SlideShare ist ein Scribd-Unternehmen logo
1 von 10
Downloaden Sie, um offline zu lesen
International Journal of Electrical and Computer Engineering (IJECE)
Vol. 10, No. 2, April 2020, pp. 1229~1238
ISSN: 2088-8708, DOI: 10.11591/ijece.v10i2.pp1229-1238  1229
Journal homepage: http://ijece.iaescore.com/index.php/IJECE
The development of a wireless LCP-based intracranial pressure
sensor for traumatic brain injury patients
Preedipat Sattayasoonthorn1
, Jackrit Suthakorn2
, Sorayouth Chamnanvej, M.D3
1
Department of Biomedical Engineering, Mahidol University, Thailand
2
Center for Biomedical and Robotics Technology, Mahidol University, Thailand
3
Department of Surgery, Mahidol University, Thailand
Article Info ABSTRACT
Article history:
Received Jun 10, 2019
Revised Oct 9, 2019
Accepted Oct 21, 2019
Raised intracranial pressure (ICP) in traumatic brain injury (TBI) patients
can lead to death. ICP measurement is required to monitor the condition of
a patient and to inform TBI treatment. This work presents a new wireless
liquid crystal polymer (LCP) based ICP sensor. The sensor is designed with
the purpose of measuring ICP and wirelessly transmitting the signal to an
external monitoring unit. The sensor is minimally invasive and
biocompatible due to the mechanical design and the use of LCP. A prototype
sensor and associated wireless module are fabricated and tested to
demonstrate the functionality and performance of the wireless LCP-based
ICP sensor. Experimental results show that the wireless LCP-based ICP
sensor can operate in the pressure range of 0 - 60.12 mmHg. Based on
repeated measurements, the sensitivity of the sensor is found to be 25.62
µVmmHg-1, with a standard deviation of ± 1.16 µVmmHg-1. This work
represents a significant step towards achieving a wireless, implantable,
minimally invasive ICP monitoring strategy for TBI patients.
Keywords:
Finite Element Method
Intracranial Pressure sensor
LCP
MEMS Fabrication
Simulation
Copyright © 2020 Institute of Advanced Engineering and Science.
All rights reserved.
Corresponding Author:
Jackrit Suthakorn,
Center for Biomedical and Robotics Technology,
Faculty of Engineering,
Mahidol University,
25/25 Puttamonthon 4 Road, Salaya, Nakorn Pathom 73170, Thailand.
Email: jackrit.sut@mahidol.ac.th
1. INTRODUCTION
Traumatic brain injury (TBI) patients require specialist care, especially concerning intracranial
pressure (ICP) monitoring. Increased ICP leads to severe brain damage, the two major consequences are
brain shift and brain ischemia [1-3]. An excessive ICP can cause disability or death to a patient. A normal
ICP range is between 5 to 10 mmHg in adults, 3 to 7 mmHg in children and 1.5 to 6 mmHg in infants [4].
There are several techniques to measure and monitor ICP. Most conventional ICP measurement methods are
invasive catheter-based procedures [5]. A number of clinical complications are encountered with catheter-
based methods, such as infection and hemorrhage [6]. Additionally, patients with a catheter-based device are
restricted to bed and lack mobility. A wireless minimally invasive ICP monitoring approach therefore is
highly desirable to overcome the aforementioned limitations of catheter-based methods [7].
Most wireless ICP devices are designed to be an implantable system that is powered and can transfer
data in order to minimize interference with the surrounding biological tissue and prevent the risk of infection.
The design constraints are the size of device, the electrical supply of the device, and the device
functionality [8]. There are two approaches to achieving a wireless implantable ICP sensor: the use of
a passive sensor,or the use of an active sensor [8–10]. A passive sensor is a battery-free device, mostly they
are based on inductive coupling which is suitable for small data packages. The principle of operation of
 ISSN: 2088-8708
Int J Elec & Comp Eng, Vol. 10, No. 2, April 2020 : 1229 - 1238
1230
a passive ICP sensor is as follows: an off-body coil is placed at an inductively coupling distance from
the implanted coil which is inside the patient’s head. A coupled magnetic field generates power to the sensor
and transfers data from the sensor.
The data is transferred from the sensor by changing the impedance of the implanted coil that is
detected by the off-body coil. The passive sensor has a low operating frequency and a short workable
distance due to the requirement for inductive coupling [11]. Recently, several groups of researchers have
focused on this approach. For example, the recent United States Food and Drug Administration (FDA)
approved ICP sensor, AURA™ ICP Monitoring System (Branchpoint Technologies, Irvine, CA, USA) is
a battery-free wireless ICP sensor in the market [12]. The AURA™ sensor receives power inductively from
the AURA™ Monitor (Model T0011B) through the AURA™ Antenna (Model T0010A). The sensor has
a catheter tip with a strain-gauge pressure sensor that extends into the brain parenchyma to measure ICP.
The measured data is transferred to the antenna which connects to a monitor. Data connection is via low
energy Bluetooth. The dimensions of the sensor are 7 mm thickness x 21 mm diameter of body and 25 mm
long, with a catheter diameter of 2 mm. This system has the advantage that the data receiver is provided to
operate with other standard patient monitors. The monitoring duration is 29 days until the accuracy of
the device shifts.
In [13] a wirelessly powered passive implant using a piezoresistive pressure sensor (Amphenol P162
NovaSensor, Amphenol Advanced Sensor, Fremont, CA, USA) was developed to measure ICP. The system
consists of two parts; the implant and external reader. Inductive coupling was applied to the design for power
transmission. This study shows that sufficient power was generated to activate the sensor for monitoring
the pressure in the range of 0 to 28 mmHg. In a later study [14] the researchers developed a data transmission
unit using a far-field antenna. The system was evaluated in a simulated biological environment.
The pressure was measured over the range of -3 to 33 mmHg and transmitted to the external receiver at
a distance up to 1 m.
In [15] the authors used a capacitive microelectromechanical system (MEMS) pressure sensor
(Murata SCB10H-B012FB, Murata Electronics Oy, Vantaa, Finland) connecting to a 50 µm spiral coil to
form an LC tank. The coil rests on the skull and connects to the MEMS sensor in the subdural through RF
coaxial cable. An increasing pressure induces a change in resonant frequency in LC tank, the changes can be
detected by an external reader antenna. The operating pressure is in the range of 0 to 70 mmHg. In [16]
a passive ICP sensor is made from two planar coils facing each other to create an LC tank. The sensor is
designed to be placed under the dura mater. When pressure is applied on the top membrane, the two coils
move closer resulting in a change of resonant frequency. A wearable readout system was proposed to detect
the pressure changes over a wide frequency range of 35 MHz – 2.7 GHz. The author suggested that
this reader is suitable for variable designs of sensors. Passive sensors have three main limitations for ICP
measurement, such as the bulky size of the coil, magnetic resonance imaging (MRI) incompatibility, and
short operating distances.
Active ICP sensors are battery-powered devices that contain the pressure sensor, data processing
and wireless communication modules. This type of sensor allows the transmission of large data packages in
shorter time periods over a longer distance and with better signal to noise ratio (SNR) than passive devices.
There are two types of battery commonly use in implantable sensor; disposable and rechargeable.
Rechargeable batteries are charged inductively from an external magnetic source. In [17] an analog wireless
ICP sensor was developed using a capacitive MEMS pressure sensor (Murata Electronics Oy, Vantaa,
Finland). The operating frequency is at the Industrial Scientific and Medical (ISM) band of 2.4 GHz.
The change of pressure is detected by the sensor which modulates a 2.4 GHz RF oscillator. The output signal
is coupled to a planar inverted - F antenna. The transmitted data is detected by the receiver held in close
distance to the head. A 3-V 220 mAh lithium coin battery (CR2032, Panasonic, Secaucus, NJ, USA)
supplies the power to all electrical components. The sensor’s performance was evaluated in both in-vitro and
in-vivo experiments.
In [18] the analog ICP sensor from [17] was implemented to be a digital device using a modified
wireless development platform (eZ430-RF2500, Texas Instruments Incorporated, Dallas, TX, USA).
The platform consists of a wireless radio (CC2500) and a microcontroller (MSP430) which connects to
the capacitive MEMS sensor. When an increasing pressure is detected, the microcontroller measures
the change in capacitance and sends the output through the wireless radio. The annular slot antenna is
connected to the wireless radio to transmit the signal to the external readout unit. The size of the digital
sensor is 22 mm width x 26 mm length x 10 mm thickness. The performance of the sensor was evaluated by
measuring the dynamic ICP changes in a swine model.
In [19] the authors proposed a wireless sensor that measures ICP indirectly via air pressure.
The system consists of an implantable sensing device and a portable data recorder. In the implantable sensing
device, an air pouch sits in contact with the cerebrospinal fluid (CSF) and converts liquid pressure into air
Int J Elec & Comp Eng ISSN: 2088-8708 
The development of a wireless LCP-based intracranial pressure sensor for … (Preedipat Sattayasoonthorn)
1231
pressure. The changes in air pressure are detected by an air pressure sensor that connects to the data
processing and transmitting part. This system was fabricated into a 3.04 mm x 2 mm system on chip (SoC).
This device uses 3 V 50 mAh battery and was tested in a hydrostatic environment. The operating pressure is
in the range of -20 to 150 mmHg. The novelty of our work is to develop a biocompatible, implantable ICP
sensor that is easy to fabricate with a low cost of manufacture that can operate during an MRI scan, none of
the reviewed work above fully satisfy these requirements.
In this work, a wireless LCP-based ICP sensor is proposed to measure the change of ICP for TBI
patients. The sensor is designed to measure the ICP in the skull and transmit the data to an external
monitoring unit. The design of the sensor consists of three main parts: the pressure sensing unit, the data
transmission unit and the power unit. The pressure sensing unit is designed to be placed on the dura mater
to detect the changes of ICP, while the data transmission and power units will be integrated into a platform
and placed externally on the skull. The sensor is designed to be a complete LCP package. Due to LCP’s
biocompatibility, it allows for a fully implantable device. The LCP-based pressure sensing unit is described
in detail in our previous work [20, 21]. A piezoresistive concept was adopted to design the sensing unit to
operate in the 0 to 50 mmHg pressure range. The LCP-based pressure sensing unit was fabricated using
standard MEMS techniques and evaluated in a hydrostatic environment. The results showed an acceptable
performance. The main contribution of the present work is the design and fabrication of an LCP-based ICP
sensor that can measure and transmit the changes of ICP to the external unit wirelessly.
Regarding to this study, the aforementioned LCP pressure sensing unit is connected to a newly
developed data transmission and power units to demonstrate the functionality of the wireless LCP-based ICP
sensor. The sensor performance is evaluated under a pressure range of 0 to 50 mmHg. Design details of
the wireless LCP sensor are given in Section 3. The experimental setup for evaluating the wireless LCP
sensor is given in Section 4. Experimental results and analysis are given in Section 5.
2. METHODOLOGY
2.1. Wireless LCP-based ICP sensor design overview
The wireless LCP-based ICP sensor is designed to measure the change of ICP within the skull.
The implantable sensor can detect the change of ICP and remotely transmit the data to the external
monitoring unit through the scalp. The sensor structure consists of three main parts: the pressure sensing unit,
the data transmission unit and the power unit as shown in Figure 1. The pressure sensing unit is designed to
be placed under the skull to detect changes in ICP in the surrounding CSF. The data transmission and power
units will be integrated into a platform and placed on the skull, underneath the scalp.
When ICP increases, the pressure sensing unit measures the changes in pressure and sends
the sensor output to the data transmission unit. The processed data is transmitted to the external monitoring
device. The power unit supplies power to the pressure sensing unit and other electrical circuits on the data
transmission and power platform as shown in Figure 1. The size of the pressure sensing unit is smaller than
the platform. The overall size of wireless LCP-based ICP sensor can be minimized in future design iterations.
The fabrication of the wireless LCP-based ICP sensor is designed to be biocompatible and
implantable through the use of LCP. The pressure sensing unit was designed based on the piezoresistive
concept and fabricated on an LCP membrane. The fabrication process and the characterization of LCP
pressure sensing unit are described in [20]. LCP has high mechanical strength, low dielectric constant and
various chemical resistance [22, 23]. It is suitable for packaging the data transmission and power unit.
The data transmission unit is designed based on 2.4 GHz ISM bands. The data transmission unit uses
Bluetooth communication to transmit data to the external monitoring unit, this design offers ease of interface
and MRI compatibility [24]. The power unit presently requires a battery to supply power to the LCP pressure
sensing unit and other circuits. An illustration of a conceptual design of the system is shown in Figure 2.
Figure 1. Overall operating principle of the wireless LCP-based ICP sensor
 ISSN: 2088-8708
Int J Elec & Comp Eng, Vol. 10, No. 2, April 2020 : 1229 - 1238
1232
Figure 2. Illustration of a conceptual design of the proposed wireless LCP-based ICP sensor
2.2 Wireless LCP-Based ICP Sensor Prototype
The LCP pressure sensing unit contains four gold strain gauges with resistances between
449-535 Ω. The structure of this unit consists of an 8 mm x 8 mm x 100 µm outer membrane and
a 2mm x 2mm x 50 µm sensing membrane above a bottom cavity. The outer membrane is bonded with
a 10 x 10 mm x 100 µm LCP membrane to seal the bottom cavity using adhesive. The LCP pressure sensing
unit is connected to the data transmission and power platform through ribbon cables.
The platform of data transmission and power units consists of a Bluetooth to serial port module
(HC-05), microcontroller (ATmega328/P, Atmel Corporation, USA), 16-bit analog-to-digital converter
(ADC) (ADS 1115, Texas Instruments Incorporated, USA), Buck-Boost Converter (TPS63001,
Texas Instruments Incorporated, USA) and 3.6 V lithium ion coin battery (LIR2450, 120 mAh, 24.5 mm
diameter). These components are presently assembled on FR4 board, and the total dimension of the platform
is 30 x 30 mm.
Figure 3 shows the block diagram of the wireless LCP-based ICP sensor. The 3.6 V Li-on battery is
used to power the LCP pressure sensing unit, ADC, microcontroller and Bluetooth module. The output
voltage of the LCP pressure sensing unit is sent to the ADS 1115 and ATmega328/P controller respectively.
The ADC resolution is 16 bits with full-scale range of ±1.024 V, which gives a resolution of 31.25 µV.
The processed data is sent via serial communication to the HC-05 Bluetooth module. The HC-05 transmits
data at 960 bps and 0 dBm RF transmit power (programmable up to +4dBm). The transmitted data is
monitored with the serial monitor feature on Arduino 1.8.8 (Arduino, Somerville, USA). The prototype of
the wireless LCP-based ICP sensor is shown in Figure 4.
Figure 3. Block diagram of the wireless ICP measurement system
Int J Elec & Comp Eng ISSN: 2088-8708 
The development of a wireless LCP-based intracranial pressure sensor for … (Preedipat Sattayasoonthorn)
1233
Figure 4. Prototype of the wireless LCP-based ICP sensor
3. EXPERIMENT
The wireless LCP-based ICP sensor is designed to operate in the pressure range of 0 to 50 mmHg.
This experiment aims to mimic the pressures ranging from 0 to 50 mmHg in ambient conditions by using an
MTS Insight Electromechnical Testing systems (MTS Systems Corporation, Minnesota, USA). Theoretically,
the pressure (P) is generated by a force (F) acting over a surface area (A) that is in direct contact with
the applied load. Applying this theory, the range of the force is calculated to correspond to the range of
the pressure. In this case, P is the pressures ranging from 0 to 50 mmHg, and A is the 8 x 8 mm2
LCP sensing
unit’s area. The range of the corresponding force is therefore 0 to 0.5 N. The MTS Insight system is set up for
a compression test with a 100 N load cell and flat compression platens. TestWorks® software (MTS Systems
Corporation, Minnesota, USA) is used to set up the input parameters and run the MTS Insight system on
a personal computer. The parameters are the maximum force of 0.5 N, the test speed of 5 μm/s and
the sampling rate of 1 Hz. A laptop is used to monitor the sensor output voltage that is measured and
remotely transmitted on serial monitor. The clocks of these two computers are synchronized to correlate
the time stamps. The overall measurement system is shown in Figure 5.
Figure 5. The experiment set up for testing wireless implantable ICP sensor
 ISSN: 2088-8708
Int J Elec & Comp Eng, Vol. 10, No. 2, April 2020 : 1229 - 1238
1234
The LCP pressure sensing unit is sandwiched between 5 mm thick silicone membranes.
The silicone membranes act as cushions and distribute the pressure over the LCP pressure sensing unit.
This sandwiched LCP pressure sensing unit is fixed on the compression platens as shown in Figure 6 (a)
and (b). When the measurement starts, the serial monitor is run before starting the compression test on
the MTS Insight system. The sensor output voltage is monitored and recorded on the serial monitor.
When the MTS Insight system runs, the load applies the force ranging from 0 to 0.5 N at the testing speed
of 5 μm/s. The forces are acquired in TestWorks® software at the sampling rate of 1 Hz. The applied load
increases until the maximum force reaches the limitation at 0.5 N. The applied forces and the time stamps
at the starting and ending points are recorded via the MTS Insight system. The time stamp at the starting
point of the MTS Insight system is aligned to the time stamp of serial monitor to correlate the forces and
the sensor output voltages. The sensor output voltages were recorded for ten repeated measurements with
the same experimental conditions.
(a) (b)
Figure 6. The wireless LCP-based ICP sensor under the compression test (a) the sandwiched LCP sensing
unit connecting to the data transmission and power platform (b) the LCP pressure sensing unit in between
two silicone membranes on compression platens.
4. RESULTS
The experiment was carried out to demonstrate the functionality and evaluate the performance of
the wireless LCP-based ICP sensor. The sensor was subjected to loading and unloading conditions
continuously. The recorded applied forces and the calculated pressures are plotted corresponding to time for
ten repeated measurements as shown in Figure 7. From the graph, the pressure was applied from the base
pressure (less than 1 mmHg) to the maximum pressure of 60.12 mmHg within approximately 412 seconds.
The sensor output voltages of each measurement are recorded and plotted with respect to the pressure as
shown in Figure 8. The output voltage linearly increases with increasing pressure.
The sensitivity of the sensor is estimated from the slope of the best-fit line fitted to the data points
for each repeated measurement, giving ten sensitivities. The average of these ten sensitivities over
the pressure range of 0 to 60.12 mmHg is found to be 25.62 µVmmHg-1
± 1.16 µV (average ± standard
deviation) as shown in Figure 9. The graph shows that the output voltage at 0 mmHg is 0.951 ± 94.34 µV.
The repeatability of the sensor is obtained from the standard deviation of the repeated measurements at
the pressures of 0, 10, 20, 30, 40 and 50 mmHg and presented as error bars as shown in Figure 9.
The graph shows small error bars which indicates that the wireless implantable ICP sensor demonstrates
good repeatability.
Figure 10 shows the residual of the best fit line of the sensor output voltage for all ten-measurement
result. The residual captures the nonlinearity of the sensor alongside the measurement noise. There is no
obvious structure to the residual plot which suggests the sensor output is very linear with respect to pressure,
this is also supported by the R2
value of 0.984, where an R2
value of 1 would indicate a perfectly linear
relationship. The standard deviation of the measurement noise evaluated from Figure 10 is found to be 47.75
µV which indicates the meaningful resolution of the sensor is approximately 2 mmHg. The resolution of
the sensor is limited by noise in this experiment but the noise may originate from the MTS Insight system
which generates a fluctuating output signal at low forces.
Int J Elec & Comp Eng ISSN: 2088-8708 
The development of a wireless LCP-based intracranial pressure sensor for … (Preedipat Sattayasoonthorn)
1235
Figure 7. Graph of recorded applied force and pressure for ten repeated measurements
Figure 8. Graph of recorded sensor output voltage over the pressure range of 0 to 60.12 mmHg for ten
repeated measurements
Figure 9. Graph of averaged output voltages under 0, 10, 20, 30, 40 and 50 mmHg pressure range
 ISSN: 2088-8708
Int J Elec & Comp Eng, Vol. 10, No. 2, April 2020 : 1229 - 1238
1236
Figure 10. Plot of the residual of the best fit line to the measurement result of the sensor output voltage for
all ten repeated measurements.
5. DISCUSSION
The goal of this work was to demonstrate the functionality and evaluate the performance of
the developed wireless LCP-based ICP sensor. The experiment shows that the MEMS fabricated LCP
pressure sensing unit can operate successfully in conjunction with the data transmission and power platform.
The wireless LCP-based ICP sensor measured changes in pressure and transmitted the real-time data to
the external monitoring device wirelessly. The sensor is able to measure the pressure from 0 to 60.12 mmHg
which is higher than the maximum design pressure. As shown in Figure 8, the output voltage increases
linearly pressure. The sensitivity of the wireless LCP-based ICP sensor obtained from the slope in Figure 9 is
lower than the simulated sensitivity reported in our previous work [20].
In future work the LCP pressure sensing unit will be refabricated to enhance the sensitivity.
The data transmission and power platform will be further minimized by removing the battery holder,
upgrading Bluetooth module and ADCs and encapsulated in LCP for packaging. The power consumption of
the system can be improved in a number of ways, for example, enhancing the resistivity of the strain gauges
in the LCP pressure sensing unit, implementing the data transmission unit with a low energy Bluetooth
module and developing a power controller to configure the work mode of the sensor. The size of the data
transmission and power unit could be further reduced in future work by replacing the data transmission and
power platform with wireless energy harvesting technologies [25, 26].
6. CONCLUSION
A wireless LCP-based ICP sensor was proposed in this work. This study proves the concept and
demonstrates the functionality of a wireless LCP-based pressure sensor to monitor the changes of ICP for
TBI patients. The proposed prototype consists of a MEMS fabricated LCP pressure sensing unit and a data
transmission and power platform. The sensor achieved a measurement sensitivity of 25.62 µVmmHg-1 with
the sampling rate of 1 sample per second over the range of 0 to 60.12 mmHg. Repeated measurements show
close agreement which indicates a high level of repeatability of the sensor. This work shows that
the proposed wireless LCP-based ICP sensor is able to operate in a pressure range of 0 to 50 mmHg which is
within the requirement for ICP monitoring for TBI patients.
ACKNOWLEDGEMENTS
This research has been funded by FY2016 Thesis Grant for Doctoral Degree Student under National
Research Council of Thailand (NRCT) through Mahidol University.
Int J Elec & Comp Eng ISSN: 2088-8708 
The development of a wireless LCP-based intracranial pressure sensor for … (Preedipat Sattayasoonthorn)
1237
REFERENCES
[1] Kawoos U, McCarron RM, Auker CR, Chavko M., “Advances in intracranial pressure monitoring and
its significance in managing traumatic brain injury,” International Journal of Molecular Sciences;
vol. 16(12), pp. 28979–97, 2015.
[2] Hyder AA, Wunderlich CA, Puvanachandra P, Gururaj G, Kobusingye OC. The impact of traumatic
brain injuries: a global perspective. NeuroRehabilitation, vol. 22(5), pp. 341–53, 2007. [Online].
Available from: http://www.ncbi.nlm.nih.gov/pubmed/18162698
[3] Schwarzbold M, Diaz A, Martins ET, Rufino A, Amante LN, Thais ME, et al., “Psychiatric disorders
and traumatic brain injury,” Neuropsychiatric Disease and Treatment, vol. 4(4), pp. 797–816, 2008.
[4] Roytowski D, Figaji A., “Raised intracranial pressure: What it is and how to recognise it,”
Continuing Medical Education, vol. 31(11), pp. 390–5, 2013. [Online]. Available from:
http://www.cmej.org.za/index.php/cmej/article/view/2909/3284.
[5] Harary M, Dolmans RGF, Gormley WB. Intracranial pressure monitoring—review and avenues for
development. Sensors (Switzerland), vol. 18(2), pp. 3–7, 2018.
[6] Zhong J, Dujovny M, Park HK, Perez E, Perlin AR, Diaz FG. Advances in ICP monitoring techniques.
Neurological Research, vol. 25(4), pp. 339–50, 2003. [Online]. Available from:
http://www.tandfonline.com/doi/full/10.1179/016164103101201661
[7] Khan M, Shallwani H, Khan M, Shamim M., “Noninvasive monitoring intracranial pressure – A review
of available modalities,” Surgical Neurology International, vol. 8(1), p. 51, 2017. [Online]. Available
from: http://surgicalneurologyint.com/surgicalint-articles/noninvasive-monitoring-intracranial-pressure-
a-review-of-available-modalities/
[8] Bashirullah R., “Wireless implants,” IEEE Microwave Magazine, vol. 11(7 SUPPL.), pp. 14–23, 2010.
[9] Yu L, Kim BJ, Meng E., “Chronically implanted pressure sensors: Challenges and state of the field,”
Sensors (Switzerland), vol. 14(11), pp. 20620–44, 2014.
[10] Hodgins D, Bertsch A, Post N, Frischholz M, Volckaerts B, Spensley J, et al., “Healthy aims:
Developing new medical implants and diagnostic equipment,” IEEE Pervasive Computing, vol. 7(1),
pp. 14–20, 2008.
[11] Joung YH., “Development of implantable medical devices: From an engineering perspective,”
International Neurourology Journal, vol. 17(3), pp. 98–106, 2013.
[12] Mapato M, Klysuban P, Kulworawanichpong T, Chomnawang N., “Metal-embedded SU-8 slab
techniques for low-resistance micromachined inductors,” International Journal of Electrical and
Computer Engineering, vol. 8(6), pp. 4772–80, 2018.
[13] Khan MWA, Björninen T, Sydänheimo L, Ukkonen L., “Remotely Powered Piezoresistive Pressure
Sensor: Toward Wireless Monitoring of Intracranial Pressure,” IEEE Microwave and Wireless
Components Letters, vol. 26(7), pp. 549–51, 2016.
[14] Khan MWA, Sydänheimo L, Ukkonen L, Björninen T., “Inductively Powered Pressure Sensing System
Integrating a Far-Field Data Transmitter for Monitoring of Intracranial Pressure,” IEEE Sensors
Journal, vol. 17(7), pp. 2191–7, 2017.
[15] Behfar MH, Björninen T, Moradi E, Sydänheimo L, Ukkonen L. Biotelemetric Wireless Intracranial
Pressure Monitoring: An In Vitro Study. International Journal of Antennas and Propagation,
vol. 1–10, 2015.
[16] Wang F, Zhang X, Shokoueinejad M, Iskandar BJ, Medow JE, Webster JG., “A Novel Intracranial
Pressure Readout Circuit for Passive Wireless LC Sensor,” IEEE Transactions on Biomedical Circuits
and Systems, vol. 11(5), pp. 1123–32, 2017.
[17] Cabello-ruiz R, Tecpoyotl-torres M, Jácome AT, Vera-dimas G, Koshevaya S, Vargas-chable P.,
“Displacement mechanical amplifiers designed on poly-silicon,” International Journal of Electrical and
Computer Engineering (IJECE), vol. 9(2), pp. 894–901, 2019.
[18] Meng X, Browne KD, Huang SM, Mietus C, Cullen DK, Tofighi MR, et al., “Dynamic evaluation of
a digital wireless intracranial pressure sensor for the assessment of traumatic brain injury in a swine
model,” IEEE Transactions on Microwave Theory and Techniques, vol. 61(1), pp. 316–25, 2013.
[19] Jiang H, Guo Y, Wu Z, Zhang C, Jia W, Wang Z., “Implantable Wireless Intracranial Pressure
Monitoring Based on Air Pressure Sensing,” IEEE Transactions on Biomedical Circuits and Systems,
vol. 12(5), pp. 1076–87, 2018.
[20] Sattayasoonthorn P, Suthakorn J, Chamnanvej S., “On the feasibility of a liquid crystal polymer
pressure sensor for intracranial pressure measurement,” Biomedical Engineering/Biomedizinische
Technik, Mar 15. 2019, [Online]. Available from: http://www.degruyter.com/view/j/bmte.ahead-of-
print/bmt-2018-0029/bmt-2018-0029.xml
 ISSN: 2088-8708
Int J Elec & Comp Eng, Vol. 10, No. 2, April 2020 : 1229 - 1238
1238
[21] Sattayasoonthorn P, Suthakorn J, Chamnanvej S, Miao J, Kottapalli AGP., “LCP MEMS implantable
pressure sensor for Intracranial Pressure measurement LCP MEMS implantable pressure sensor
for Intracranial Pressure measurement,” In: The 7th IEEE International Conference on
Nano/Molecular Medicine and Engineering IEEE, p. 63–7, 2013. [Online]. Available from:
http://ieeexplore.ieee.org/document/6766317/
[22] Wang X, Engel J, Liu C., “Liquid crystal polymer for MEMS: Processes and applications. Journal of
Micromechanics and Microengineering; vol. 13, pp. 628–633, 2003. [Online]. Available from:
http://www.iop.org/EJ/abstract/0960-1317/13/5/314.
[23] Bouneb I, Kerrour F., “Nanometric modelization of gas structure, multidimensional using comsol
software,” International Journal of Electrical and Computer Engineering, vol. 8(4), pp. 2014–20, 2018.
[24] Vogt C, Reber J, Waltisberg D, Buthe L, Marjanovic J, Munzenrieder N, et al. “A wearable bluetooth le
sensor for patient monitoring during MRI scans,” Proceedings of the Annual International Conference
of the IEEE Engineering in Medicine and Biology Society, EMBS. 2016 pp. 4975–8, Oct 2016.
[25] Stephen NG., “On energy harvesting from ambient vibration,” Journal of Sound and Vibration,
vol. 293(1–2), pp. 409–25, 2006.
[26] Nanda A, Karami MA. “Energy harvesting from arterial blood pressure for powering embedded micro
sensors in human brain,” Journal of Applied Physics, vol. 121(12), 2017.

Weitere ähnliche Inhalte

Was ist angesagt?

A low-cost electro-cardiograph machine equipped with sensitivity and paper sp...
A low-cost electro-cardiograph machine equipped with sensitivity and paper sp...A low-cost electro-cardiograph machine equipped with sensitivity and paper sp...
A low-cost electro-cardiograph machine equipped with sensitivity and paper sp...TELKOMNIKA JOURNAL
 
A simple portable ecg monitor with iot
A simple portable ecg monitor with iotA simple portable ecg monitor with iot
A simple portable ecg monitor with iotArhamSheikh1
 
A Real Time Electrocardiogram (ECG) Device for Cardiac Patients
A Real Time Electrocardiogram (ECG) Device for Cardiac PatientsA Real Time Electrocardiogram (ECG) Device for Cardiac Patients
A Real Time Electrocardiogram (ECG) Device for Cardiac PatientsIJERD Editor
 
Instant elelectrocardiogram monitoring in android smart phones
Instant elelectrocardiogram monitoring in android smart phonesInstant elelectrocardiogram monitoring in android smart phones
Instant elelectrocardiogram monitoring in android smart phonesIjrdt Journal
 
A wearable ecg recording system for continuous arrhythmia
A wearable ecg recording system for continuous arrhythmiaA wearable ecg recording system for continuous arrhythmia
A wearable ecg recording system for continuous arrhythmiaBarracca
 
Smart hospital technology
Smart hospital technologySmart hospital technology
Smart hospital technologyhiij
 
International Journal of Computational Engineering Research(IJCER)
International Journal of Computational Engineering Research(IJCER) International Journal of Computational Engineering Research(IJCER)
International Journal of Computational Engineering Research(IJCER) ijceronline
 
Real time heart monitoring system
Real time heart monitoring systemReal time heart monitoring system
Real time heart monitoring systemShashank Kapoor
 
A Biomedical Smart Sensor for Visually impaired
A Biomedical Smart Sensor for Visually impairedA Biomedical Smart Sensor for Visually impaired
A Biomedical Smart Sensor for Visually impairedDinesh Mv
 
wireless ECG system based on android
wireless ECG system based on androidwireless ECG system based on android
wireless ECG system based on androidGhadeerAlsandi
 
Implementation of ecg signal acquisition and transmission through bluetooth t...
Implementation of ecg signal acquisition and transmission through bluetooth t...Implementation of ecg signal acquisition and transmission through bluetooth t...
Implementation of ecg signal acquisition and transmission through bluetooth t...eSAT Publishing House
 
Arduino Based Abnormal Heart Rate Detection and Wireless Communication
Arduino Based Abnormal Heart Rate Detection and Wireless CommunicationArduino Based Abnormal Heart Rate Detection and Wireless Communication
Arduino Based Abnormal Heart Rate Detection and Wireless Communicationijcisjournal
 
A Wireless ECG Plaster for Real-Time Cardiac Health Monitoring in Body Senso...
A Wireless ECG Plaster for Real-Time Cardiac  Health Monitoring in Body Senso...A Wireless ECG Plaster for Real-Time Cardiac  Health Monitoring in Body Senso...
A Wireless ECG Plaster for Real-Time Cardiac Health Monitoring in Body Senso...ecgpapers
 
Wireless Telemetry System
Wireless Telemetry SystemWireless Telemetry System
Wireless Telemetry Systemijsrd.com
 

Was ist angesagt? (17)

Sensors 21-02777
Sensors 21-02777Sensors 21-02777
Sensors 21-02777
 
A low-cost electro-cardiograph machine equipped with sensitivity and paper sp...
A low-cost electro-cardiograph machine equipped with sensitivity and paper sp...A low-cost electro-cardiograph machine equipped with sensitivity and paper sp...
A low-cost electro-cardiograph machine equipped with sensitivity and paper sp...
 
A simple portable ecg monitor with iot
A simple portable ecg monitor with iotA simple portable ecg monitor with iot
A simple portable ecg monitor with iot
 
ECG Report_2014
ECG Report_2014ECG Report_2014
ECG Report_2014
 
A Real Time Electrocardiogram (ECG) Device for Cardiac Patients
A Real Time Electrocardiogram (ECG) Device for Cardiac PatientsA Real Time Electrocardiogram (ECG) Device for Cardiac Patients
A Real Time Electrocardiogram (ECG) Device for Cardiac Patients
 
Seminar
SeminarSeminar
Seminar
 
Instant elelectrocardiogram monitoring in android smart phones
Instant elelectrocardiogram monitoring in android smart phonesInstant elelectrocardiogram monitoring in android smart phones
Instant elelectrocardiogram monitoring in android smart phones
 
A wearable ecg recording system for continuous arrhythmia
A wearable ecg recording system for continuous arrhythmiaA wearable ecg recording system for continuous arrhythmia
A wearable ecg recording system for continuous arrhythmia
 
Smart hospital technology
Smart hospital technologySmart hospital technology
Smart hospital technology
 
International Journal of Computational Engineering Research(IJCER)
International Journal of Computational Engineering Research(IJCER) International Journal of Computational Engineering Research(IJCER)
International Journal of Computational Engineering Research(IJCER)
 
Real time heart monitoring system
Real time heart monitoring systemReal time heart monitoring system
Real time heart monitoring system
 
A Biomedical Smart Sensor for Visually impaired
A Biomedical Smart Sensor for Visually impairedA Biomedical Smart Sensor for Visually impaired
A Biomedical Smart Sensor for Visually impaired
 
wireless ECG system based on android
wireless ECG system based on androidwireless ECG system based on android
wireless ECG system based on android
 
Implementation of ecg signal acquisition and transmission through bluetooth t...
Implementation of ecg signal acquisition and transmission through bluetooth t...Implementation of ecg signal acquisition and transmission through bluetooth t...
Implementation of ecg signal acquisition and transmission through bluetooth t...
 
Arduino Based Abnormal Heart Rate Detection and Wireless Communication
Arduino Based Abnormal Heart Rate Detection and Wireless CommunicationArduino Based Abnormal Heart Rate Detection and Wireless Communication
Arduino Based Abnormal Heart Rate Detection and Wireless Communication
 
A Wireless ECG Plaster for Real-Time Cardiac Health Monitoring in Body Senso...
A Wireless ECG Plaster for Real-Time Cardiac  Health Monitoring in Body Senso...A Wireless ECG Plaster for Real-Time Cardiac  Health Monitoring in Body Senso...
A Wireless ECG Plaster for Real-Time Cardiac Health Monitoring in Body Senso...
 
Wireless Telemetry System
Wireless Telemetry SystemWireless Telemetry System
Wireless Telemetry System
 

Ähnlich wie The development of a wireless LCP-based intracranial pressure sensor for traumatic brain injury patients

Design and Implementation of Real Time Remote Supervisory System
Design and Implementation of Real Time Remote Supervisory SystemDesign and Implementation of Real Time Remote Supervisory System
Design and Implementation of Real Time Remote Supervisory SystemIJERA Editor
 
Patient Monitoring System
Patient Monitoring SystemPatient Monitoring System
Patient Monitoring SystemIJERA Editor
 
Paper id 21201422
Paper id 21201422Paper id 21201422
Paper id 21201422IJRAT
 
Portable Real Time Cardiac Activity Monitoring System
Portable  Real Time Cardiac Activity Monitoring SystemPortable  Real Time Cardiac Activity Monitoring System
Portable Real Time Cardiac Activity Monitoring SystemIRJET Journal
 
IRJET- Wireless Healthcare Monitoring using Android Phones
IRJET- Wireless Healthcare Monitoring using Android PhonesIRJET- Wireless Healthcare Monitoring using Android Phones
IRJET- Wireless Healthcare Monitoring using Android PhonesIRJET Journal
 
A Healthcare Monitoring System Using Wireless Sensor Network With GSM
A Healthcare Monitoring System Using Wireless Sensor Network With GSMA Healthcare Monitoring System Using Wireless Sensor Network With GSM
A Healthcare Monitoring System Using Wireless Sensor Network With GSMIRJET Journal
 
IRJET- Patient Monitoring System
IRJET- Patient Monitoring SystemIRJET- Patient Monitoring System
IRJET- Patient Monitoring SystemIRJET Journal
 
Electrocardiogram signal processing algorithm on microcontroller using wavele...
Electrocardiogram signal processing algorithm on microcontroller using wavele...Electrocardiogram signal processing algorithm on microcontroller using wavele...
Electrocardiogram signal processing algorithm on microcontroller using wavele...IJECEIAES
 
IRJET- Human Health Monitoring using Redtacton Transceiver
IRJET- Human Health Monitoring using Redtacton TransceiverIRJET- Human Health Monitoring using Redtacton Transceiver
IRJET- Human Health Monitoring using Redtacton TransceiverIRJET Journal
 
Transmission of arm based real time ecg for monitoring remotely located patient
Transmission of arm based real time ecg for monitoring remotely located patientTransmission of arm based real time ecg for monitoring remotely located patient
Transmission of arm based real time ecg for monitoring remotely located patienteSAT Publishing House
 
IRJET- Design and Implementation of Health Monitoring System
IRJET-  	  Design and Implementation of Health Monitoring SystemIRJET-  	  Design and Implementation of Health Monitoring System
IRJET- Design and Implementation of Health Monitoring SystemIRJET Journal
 
A Low Power Wearable Physiological Parameter Monitoring System
A Low Power Wearable Physiological Parameter Monitoring SystemA Low Power Wearable Physiological Parameter Monitoring System
A Low Power Wearable Physiological Parameter Monitoring Systemijsrd.com
 
Body Temperature & Blood Pressure Remote Monitoring
Body Temperature & Blood Pressure Remote MonitoringBody Temperature & Blood Pressure Remote Monitoring
Body Temperature & Blood Pressure Remote MonitoringIJMTST Journal
 
Real Time ECG and Saline Level Monitoring System Using Arduino UNO Processor
Real Time ECG and Saline Level Monitoring System Using Arduino UNO ProcessorReal Time ECG and Saline Level Monitoring System Using Arduino UNO Processor
Real Time ECG and Saline Level Monitoring System Using Arduino UNO ProcessorAssociate Professor in VSB Coimbatore
 
Intra body communication in biomedical 1
Intra body communication in biomedical 1Intra body communication in biomedical 1
Intra body communication in biomedical 1suvedhajeyaraman
 
SMART HOSPITAL TECHNOLOGY
SMART HOSPITAL TECHNOLOGYSMART HOSPITAL TECHNOLOGY
SMART HOSPITAL TECHNOLOGYhiij
 

Ähnlich wie The development of a wireless LCP-based intracranial pressure sensor for traumatic brain injury patients (20)

Design and Implementation of Real Time Remote Supervisory System
Design and Implementation of Real Time Remote Supervisory SystemDesign and Implementation of Real Time Remote Supervisory System
Design and Implementation of Real Time Remote Supervisory System
 
Patient Monitoring System
Patient Monitoring SystemPatient Monitoring System
Patient Monitoring System
 
Paper id 21201422
Paper id 21201422Paper id 21201422
Paper id 21201422
 
Portable Real Time Cardiac Activity Monitoring System
Portable  Real Time Cardiac Activity Monitoring SystemPortable  Real Time Cardiac Activity Monitoring System
Portable Real Time Cardiac Activity Monitoring System
 
IRJET- Wireless Healthcare Monitoring using Android Phones
IRJET- Wireless Healthcare Monitoring using Android PhonesIRJET- Wireless Healthcare Monitoring using Android Phones
IRJET- Wireless Healthcare Monitoring using Android Phones
 
A Healthcare Monitoring System Using Wireless Sensor Network With GSM
A Healthcare Monitoring System Using Wireless Sensor Network With GSMA Healthcare Monitoring System Using Wireless Sensor Network With GSM
A Healthcare Monitoring System Using Wireless Sensor Network With GSM
 
IJET-V3I1P26
IJET-V3I1P26IJET-V3I1P26
IJET-V3I1P26
 
IRJET- Patient Monitoring System
IRJET- Patient Monitoring SystemIRJET- Patient Monitoring System
IRJET- Patient Monitoring System
 
Electrocardiogram signal processing algorithm on microcontroller using wavele...
Electrocardiogram signal processing algorithm on microcontroller using wavele...Electrocardiogram signal processing algorithm on microcontroller using wavele...
Electrocardiogram signal processing algorithm on microcontroller using wavele...
 
Wireless Sensor Networks for Monitoring Physiological Signals of Multiple Pat...
Wireless Sensor Networks for Monitoring Physiological Signals of Multiple Pat...Wireless Sensor Networks for Monitoring Physiological Signals of Multiple Pat...
Wireless Sensor Networks for Monitoring Physiological Signals of Multiple Pat...
 
IRJET- Human Health Monitoring using Redtacton Transceiver
IRJET- Human Health Monitoring using Redtacton TransceiverIRJET- Human Health Monitoring using Redtacton Transceiver
IRJET- Human Health Monitoring using Redtacton Transceiver
 
Transmission of arm based real time ecg for monitoring remotely located patient
Transmission of arm based real time ecg for monitoring remotely located patientTransmission of arm based real time ecg for monitoring remotely located patient
Transmission of arm based real time ecg for monitoring remotely located patient
 
IRJET- Design and Implementation of Health Monitoring System
IRJET-  	  Design and Implementation of Health Monitoring SystemIRJET-  	  Design and Implementation of Health Monitoring System
IRJET- Design and Implementation of Health Monitoring System
 
A Low Power Wearable Physiological Parameter Monitoring System
A Low Power Wearable Physiological Parameter Monitoring SystemA Low Power Wearable Physiological Parameter Monitoring System
A Low Power Wearable Physiological Parameter Monitoring System
 
Body Temperature & Blood Pressure Remote Monitoring
Body Temperature & Blood Pressure Remote MonitoringBody Temperature & Blood Pressure Remote Monitoring
Body Temperature & Blood Pressure Remote Monitoring
 
Closed Loop DBS
Closed Loop DBSClosed Loop DBS
Closed Loop DBS
 
J05136669
J05136669J05136669
J05136669
 
Real Time ECG and Saline Level Monitoring System Using Arduino UNO Processor
Real Time ECG and Saline Level Monitoring System Using Arduino UNO ProcessorReal Time ECG and Saline Level Monitoring System Using Arduino UNO Processor
Real Time ECG and Saline Level Monitoring System Using Arduino UNO Processor
 
Intra body communication in biomedical 1
Intra body communication in biomedical 1Intra body communication in biomedical 1
Intra body communication in biomedical 1
 
SMART HOSPITAL TECHNOLOGY
SMART HOSPITAL TECHNOLOGYSMART HOSPITAL TECHNOLOGY
SMART HOSPITAL TECHNOLOGY
 

Mehr von IJECEIAES

Predicting churn with filter-based techniques and deep learning
Predicting churn with filter-based techniques and deep learningPredicting churn with filter-based techniques and deep learning
Predicting churn with filter-based techniques and deep learningIJECEIAES
 
Taxi-out time prediction at Mohammed V Casablanca Airport
Taxi-out time prediction at Mohammed V Casablanca AirportTaxi-out time prediction at Mohammed V Casablanca Airport
Taxi-out time prediction at Mohammed V Casablanca AirportIJECEIAES
 
Automatic customer review summarization using deep learningbased hybrid senti...
Automatic customer review summarization using deep learningbased hybrid senti...Automatic customer review summarization using deep learningbased hybrid senti...
Automatic customer review summarization using deep learningbased hybrid senti...IJECEIAES
 
Ataxic person prediction using feature optimized based on machine learning model
Ataxic person prediction using feature optimized based on machine learning modelAtaxic person prediction using feature optimized based on machine learning model
Ataxic person prediction using feature optimized based on machine learning modelIJECEIAES
 
Situational judgment test measures administrator computational thinking with ...
Situational judgment test measures administrator computational thinking with ...Situational judgment test measures administrator computational thinking with ...
Situational judgment test measures administrator computational thinking with ...IJECEIAES
 
Hand LightWeightNet: an optimized hand pose estimation for interactive mobile...
Hand LightWeightNet: an optimized hand pose estimation for interactive mobile...Hand LightWeightNet: an optimized hand pose estimation for interactive mobile...
Hand LightWeightNet: an optimized hand pose estimation for interactive mobile...IJECEIAES
 
An overlapping conscious relief-based feature subset selection method
An overlapping conscious relief-based feature subset selection methodAn overlapping conscious relief-based feature subset selection method
An overlapping conscious relief-based feature subset selection methodIJECEIAES
 
Recognition of music symbol notation using convolutional neural network
Recognition of music symbol notation using convolutional neural networkRecognition of music symbol notation using convolutional neural network
Recognition of music symbol notation using convolutional neural networkIJECEIAES
 
A simplified classification computational model of opinion mining using deep ...
A simplified classification computational model of opinion mining using deep ...A simplified classification computational model of opinion mining using deep ...
A simplified classification computational model of opinion mining using deep ...IJECEIAES
 
An efficient convolutional neural network-extreme gradient boosting hybrid de...
An efficient convolutional neural network-extreme gradient boosting hybrid de...An efficient convolutional neural network-extreme gradient boosting hybrid de...
An efficient convolutional neural network-extreme gradient boosting hybrid de...IJECEIAES
 
Generating images using generative adversarial networks based on text descrip...
Generating images using generative adversarial networks based on text descrip...Generating images using generative adversarial networks based on text descrip...
Generating images using generative adversarial networks based on text descrip...IJECEIAES
 
Collusion-resistant multiparty data sharing in social networks
Collusion-resistant multiparty data sharing in social networksCollusion-resistant multiparty data sharing in social networks
Collusion-resistant multiparty data sharing in social networksIJECEIAES
 
Application of deep learning methods for automated analysis of retinal struct...
Application of deep learning methods for automated analysis of retinal struct...Application of deep learning methods for automated analysis of retinal struct...
Application of deep learning methods for automated analysis of retinal struct...IJECEIAES
 
Proposal of a similarity measure for unified modeling language class diagram ...
Proposal of a similarity measure for unified modeling language class diagram ...Proposal of a similarity measure for unified modeling language class diagram ...
Proposal of a similarity measure for unified modeling language class diagram ...IJECEIAES
 
Efficient criticality oriented service brokering policy in cloud datacenters
Efficient criticality oriented service brokering policy in cloud datacentersEfficient criticality oriented service brokering policy in cloud datacenters
Efficient criticality oriented service brokering policy in cloud datacentersIJECEIAES
 
System call frequency analysis-based generative adversarial network model for...
System call frequency analysis-based generative adversarial network model for...System call frequency analysis-based generative adversarial network model for...
System call frequency analysis-based generative adversarial network model for...IJECEIAES
 
Comparison of Iris dataset classification with Gaussian naïve Bayes and decis...
Comparison of Iris dataset classification with Gaussian naïve Bayes and decis...Comparison of Iris dataset classification with Gaussian naïve Bayes and decis...
Comparison of Iris dataset classification with Gaussian naïve Bayes and decis...IJECEIAES
 
Efficient intelligent crawler for hamming distance based on prioritization of...
Efficient intelligent crawler for hamming distance based on prioritization of...Efficient intelligent crawler for hamming distance based on prioritization of...
Efficient intelligent crawler for hamming distance based on prioritization of...IJECEIAES
 
Predictive modeling for breast cancer based on machine learning algorithms an...
Predictive modeling for breast cancer based on machine learning algorithms an...Predictive modeling for breast cancer based on machine learning algorithms an...
Predictive modeling for breast cancer based on machine learning algorithms an...IJECEIAES
 
An algorithm for decomposing variations of 3D model
An algorithm for decomposing variations of 3D modelAn algorithm for decomposing variations of 3D model
An algorithm for decomposing variations of 3D modelIJECEIAES
 

Mehr von IJECEIAES (20)

Predicting churn with filter-based techniques and deep learning
Predicting churn with filter-based techniques and deep learningPredicting churn with filter-based techniques and deep learning
Predicting churn with filter-based techniques and deep learning
 
Taxi-out time prediction at Mohammed V Casablanca Airport
Taxi-out time prediction at Mohammed V Casablanca AirportTaxi-out time prediction at Mohammed V Casablanca Airport
Taxi-out time prediction at Mohammed V Casablanca Airport
 
Automatic customer review summarization using deep learningbased hybrid senti...
Automatic customer review summarization using deep learningbased hybrid senti...Automatic customer review summarization using deep learningbased hybrid senti...
Automatic customer review summarization using deep learningbased hybrid senti...
 
Ataxic person prediction using feature optimized based on machine learning model
Ataxic person prediction using feature optimized based on machine learning modelAtaxic person prediction using feature optimized based on machine learning model
Ataxic person prediction using feature optimized based on machine learning model
 
Situational judgment test measures administrator computational thinking with ...
Situational judgment test measures administrator computational thinking with ...Situational judgment test measures administrator computational thinking with ...
Situational judgment test measures administrator computational thinking with ...
 
Hand LightWeightNet: an optimized hand pose estimation for interactive mobile...
Hand LightWeightNet: an optimized hand pose estimation for interactive mobile...Hand LightWeightNet: an optimized hand pose estimation for interactive mobile...
Hand LightWeightNet: an optimized hand pose estimation for interactive mobile...
 
An overlapping conscious relief-based feature subset selection method
An overlapping conscious relief-based feature subset selection methodAn overlapping conscious relief-based feature subset selection method
An overlapping conscious relief-based feature subset selection method
 
Recognition of music symbol notation using convolutional neural network
Recognition of music symbol notation using convolutional neural networkRecognition of music symbol notation using convolutional neural network
Recognition of music symbol notation using convolutional neural network
 
A simplified classification computational model of opinion mining using deep ...
A simplified classification computational model of opinion mining using deep ...A simplified classification computational model of opinion mining using deep ...
A simplified classification computational model of opinion mining using deep ...
 
An efficient convolutional neural network-extreme gradient boosting hybrid de...
An efficient convolutional neural network-extreme gradient boosting hybrid de...An efficient convolutional neural network-extreme gradient boosting hybrid de...
An efficient convolutional neural network-extreme gradient boosting hybrid de...
 
Generating images using generative adversarial networks based on text descrip...
Generating images using generative adversarial networks based on text descrip...Generating images using generative adversarial networks based on text descrip...
Generating images using generative adversarial networks based on text descrip...
 
Collusion-resistant multiparty data sharing in social networks
Collusion-resistant multiparty data sharing in social networksCollusion-resistant multiparty data sharing in social networks
Collusion-resistant multiparty data sharing in social networks
 
Application of deep learning methods for automated analysis of retinal struct...
Application of deep learning methods for automated analysis of retinal struct...Application of deep learning methods for automated analysis of retinal struct...
Application of deep learning methods for automated analysis of retinal struct...
 
Proposal of a similarity measure for unified modeling language class diagram ...
Proposal of a similarity measure for unified modeling language class diagram ...Proposal of a similarity measure for unified modeling language class diagram ...
Proposal of a similarity measure for unified modeling language class diagram ...
 
Efficient criticality oriented service brokering policy in cloud datacenters
Efficient criticality oriented service brokering policy in cloud datacentersEfficient criticality oriented service brokering policy in cloud datacenters
Efficient criticality oriented service brokering policy in cloud datacenters
 
System call frequency analysis-based generative adversarial network model for...
System call frequency analysis-based generative adversarial network model for...System call frequency analysis-based generative adversarial network model for...
System call frequency analysis-based generative adversarial network model for...
 
Comparison of Iris dataset classification with Gaussian naïve Bayes and decis...
Comparison of Iris dataset classification with Gaussian naïve Bayes and decis...Comparison of Iris dataset classification with Gaussian naïve Bayes and decis...
Comparison of Iris dataset classification with Gaussian naïve Bayes and decis...
 
Efficient intelligent crawler for hamming distance based on prioritization of...
Efficient intelligent crawler for hamming distance based on prioritization of...Efficient intelligent crawler for hamming distance based on prioritization of...
Efficient intelligent crawler for hamming distance based on prioritization of...
 
Predictive modeling for breast cancer based on machine learning algorithms an...
Predictive modeling for breast cancer based on machine learning algorithms an...Predictive modeling for breast cancer based on machine learning algorithms an...
Predictive modeling for breast cancer based on machine learning algorithms an...
 
An algorithm for decomposing variations of 3D model
An algorithm for decomposing variations of 3D modelAn algorithm for decomposing variations of 3D model
An algorithm for decomposing variations of 3D model
 

Kürzlich hochgeladen

Unit 1 - Soil Classification and Compaction.pdf
Unit 1 - Soil Classification and Compaction.pdfUnit 1 - Soil Classification and Compaction.pdf
Unit 1 - Soil Classification and Compaction.pdfRagavanV2
 
Thermal Engineering -unit - III & IV.ppt
Thermal Engineering -unit - III & IV.pptThermal Engineering -unit - III & IV.ppt
Thermal Engineering -unit - III & IV.pptDineshKumar4165
 
Bhosari ( Call Girls ) Pune 6297143586 Hot Model With Sexy Bhabi Ready For ...
Bhosari ( Call Girls ) Pune  6297143586  Hot Model With Sexy Bhabi Ready For ...Bhosari ( Call Girls ) Pune  6297143586  Hot Model With Sexy Bhabi Ready For ...
Bhosari ( Call Girls ) Pune 6297143586 Hot Model With Sexy Bhabi Ready For ...tanu pandey
 
Unit 2- Effective stress & Permeability.pdf
Unit 2- Effective stress & Permeability.pdfUnit 2- Effective stress & Permeability.pdf
Unit 2- Effective stress & Permeability.pdfRagavanV2
 
KubeKraft presentation @CloudNativeHooghly
KubeKraft presentation @CloudNativeHooghlyKubeKraft presentation @CloudNativeHooghly
KubeKraft presentation @CloudNativeHooghlysanyuktamishra911
 
Call Girls In Bangalore ☎ 7737669865 🥵 Book Your One night Stand
Call Girls In Bangalore ☎ 7737669865 🥵 Book Your One night StandCall Girls In Bangalore ☎ 7737669865 🥵 Book Your One night Stand
Call Girls In Bangalore ☎ 7737669865 🥵 Book Your One night Standamitlee9823
 
Thermal Engineering-R & A / C - unit - V
Thermal Engineering-R & A / C - unit - VThermal Engineering-R & A / C - unit - V
Thermal Engineering-R & A / C - unit - VDineshKumar4165
 
Hostel management system project report..pdf
Hostel management system project report..pdfHostel management system project report..pdf
Hostel management system project report..pdfKamal Acharya
 
Design For Accessibility: Getting it right from the start
Design For Accessibility: Getting it right from the startDesign For Accessibility: Getting it right from the start
Design For Accessibility: Getting it right from the startQuintin Balsdon
 
COST-EFFETIVE and Energy Efficient BUILDINGS ptx
COST-EFFETIVE  and Energy Efficient BUILDINGS ptxCOST-EFFETIVE  and Energy Efficient BUILDINGS ptx
COST-EFFETIVE and Energy Efficient BUILDINGS ptxJIT KUMAR GUPTA
 
VIP Call Girls Palanpur 7001035870 Whatsapp Number, 24/07 Booking
VIP Call Girls Palanpur 7001035870 Whatsapp Number, 24/07 BookingVIP Call Girls Palanpur 7001035870 Whatsapp Number, 24/07 Booking
VIP Call Girls Palanpur 7001035870 Whatsapp Number, 24/07 Bookingdharasingh5698
 
Hazard Identification (HAZID) vs. Hazard and Operability (HAZOP): A Comparati...
Hazard Identification (HAZID) vs. Hazard and Operability (HAZOP): A Comparati...Hazard Identification (HAZID) vs. Hazard and Operability (HAZOP): A Comparati...
Hazard Identification (HAZID) vs. Hazard and Operability (HAZOP): A Comparati...soginsider
 
VIP Model Call Girls Kothrud ( Pune ) Call ON 8005736733 Starting From 5K to ...
VIP Model Call Girls Kothrud ( Pune ) Call ON 8005736733 Starting From 5K to ...VIP Model Call Girls Kothrud ( Pune ) Call ON 8005736733 Starting From 5K to ...
VIP Model Call Girls Kothrud ( Pune ) Call ON 8005736733 Starting From 5K to ...SUHANI PANDEY
 
FULL ENJOY Call Girls In Mahipalpur Delhi Contact Us 8377877756
FULL ENJOY Call Girls In Mahipalpur Delhi Contact Us 8377877756FULL ENJOY Call Girls In Mahipalpur Delhi Contact Us 8377877756
FULL ENJOY Call Girls In Mahipalpur Delhi Contact Us 8377877756dollysharma2066
 

Kürzlich hochgeladen (20)

Call Girls in Ramesh Nagar Delhi 💯 Call Us 🔝9953056974 🔝 Escort Service
Call Girls in Ramesh Nagar Delhi 💯 Call Us 🔝9953056974 🔝 Escort ServiceCall Girls in Ramesh Nagar Delhi 💯 Call Us 🔝9953056974 🔝 Escort Service
Call Girls in Ramesh Nagar Delhi 💯 Call Us 🔝9953056974 🔝 Escort Service
 
Integrated Test Rig For HTFE-25 - Neometrix
Integrated Test Rig For HTFE-25 - NeometrixIntegrated Test Rig For HTFE-25 - Neometrix
Integrated Test Rig For HTFE-25 - Neometrix
 
Unit 1 - Soil Classification and Compaction.pdf
Unit 1 - Soil Classification and Compaction.pdfUnit 1 - Soil Classification and Compaction.pdf
Unit 1 - Soil Classification and Compaction.pdf
 
Thermal Engineering -unit - III & IV.ppt
Thermal Engineering -unit - III & IV.pptThermal Engineering -unit - III & IV.ppt
Thermal Engineering -unit - III & IV.ppt
 
(INDIRA) Call Girl Bhosari Call Now 8617697112 Bhosari Escorts 24x7
(INDIRA) Call Girl Bhosari Call Now 8617697112 Bhosari Escorts 24x7(INDIRA) Call Girl Bhosari Call Now 8617697112 Bhosari Escorts 24x7
(INDIRA) Call Girl Bhosari Call Now 8617697112 Bhosari Escorts 24x7
 
Call Now ≽ 9953056974 ≼🔝 Call Girls In New Ashok Nagar ≼🔝 Delhi door step de...
Call Now ≽ 9953056974 ≼🔝 Call Girls In New Ashok Nagar  ≼🔝 Delhi door step de...Call Now ≽ 9953056974 ≼🔝 Call Girls In New Ashok Nagar  ≼🔝 Delhi door step de...
Call Now ≽ 9953056974 ≼🔝 Call Girls In New Ashok Nagar ≼🔝 Delhi door step de...
 
Bhosari ( Call Girls ) Pune 6297143586 Hot Model With Sexy Bhabi Ready For ...
Bhosari ( Call Girls ) Pune  6297143586  Hot Model With Sexy Bhabi Ready For ...Bhosari ( Call Girls ) Pune  6297143586  Hot Model With Sexy Bhabi Ready For ...
Bhosari ( Call Girls ) Pune 6297143586 Hot Model With Sexy Bhabi Ready For ...
 
Unit 2- Effective stress & Permeability.pdf
Unit 2- Effective stress & Permeability.pdfUnit 2- Effective stress & Permeability.pdf
Unit 2- Effective stress & Permeability.pdf
 
KubeKraft presentation @CloudNativeHooghly
KubeKraft presentation @CloudNativeHooghlyKubeKraft presentation @CloudNativeHooghly
KubeKraft presentation @CloudNativeHooghly
 
Call Girls In Bangalore ☎ 7737669865 🥵 Book Your One night Stand
Call Girls In Bangalore ☎ 7737669865 🥵 Book Your One night StandCall Girls In Bangalore ☎ 7737669865 🥵 Book Your One night Stand
Call Girls In Bangalore ☎ 7737669865 🥵 Book Your One night Stand
 
Thermal Engineering-R & A / C - unit - V
Thermal Engineering-R & A / C - unit - VThermal Engineering-R & A / C - unit - V
Thermal Engineering-R & A / C - unit - V
 
Hostel management system project report..pdf
Hostel management system project report..pdfHostel management system project report..pdf
Hostel management system project report..pdf
 
Design For Accessibility: Getting it right from the start
Design For Accessibility: Getting it right from the startDesign For Accessibility: Getting it right from the start
Design For Accessibility: Getting it right from the start
 
Call Girls in Netaji Nagar, Delhi 💯 Call Us 🔝9953056974 🔝 Escort Service
Call Girls in Netaji Nagar, Delhi 💯 Call Us 🔝9953056974 🔝 Escort ServiceCall Girls in Netaji Nagar, Delhi 💯 Call Us 🔝9953056974 🔝 Escort Service
Call Girls in Netaji Nagar, Delhi 💯 Call Us 🔝9953056974 🔝 Escort Service
 
(INDIRA) Call Girl Aurangabad Call Now 8617697112 Aurangabad Escorts 24x7
(INDIRA) Call Girl Aurangabad Call Now 8617697112 Aurangabad Escorts 24x7(INDIRA) Call Girl Aurangabad Call Now 8617697112 Aurangabad Escorts 24x7
(INDIRA) Call Girl Aurangabad Call Now 8617697112 Aurangabad Escorts 24x7
 
COST-EFFETIVE and Energy Efficient BUILDINGS ptx
COST-EFFETIVE  and Energy Efficient BUILDINGS ptxCOST-EFFETIVE  and Energy Efficient BUILDINGS ptx
COST-EFFETIVE and Energy Efficient BUILDINGS ptx
 
VIP Call Girls Palanpur 7001035870 Whatsapp Number, 24/07 Booking
VIP Call Girls Palanpur 7001035870 Whatsapp Number, 24/07 BookingVIP Call Girls Palanpur 7001035870 Whatsapp Number, 24/07 Booking
VIP Call Girls Palanpur 7001035870 Whatsapp Number, 24/07 Booking
 
Hazard Identification (HAZID) vs. Hazard and Operability (HAZOP): A Comparati...
Hazard Identification (HAZID) vs. Hazard and Operability (HAZOP): A Comparati...Hazard Identification (HAZID) vs. Hazard and Operability (HAZOP): A Comparati...
Hazard Identification (HAZID) vs. Hazard and Operability (HAZOP): A Comparati...
 
VIP Model Call Girls Kothrud ( Pune ) Call ON 8005736733 Starting From 5K to ...
VIP Model Call Girls Kothrud ( Pune ) Call ON 8005736733 Starting From 5K to ...VIP Model Call Girls Kothrud ( Pune ) Call ON 8005736733 Starting From 5K to ...
VIP Model Call Girls Kothrud ( Pune ) Call ON 8005736733 Starting From 5K to ...
 
FULL ENJOY Call Girls In Mahipalpur Delhi Contact Us 8377877756
FULL ENJOY Call Girls In Mahipalpur Delhi Contact Us 8377877756FULL ENJOY Call Girls In Mahipalpur Delhi Contact Us 8377877756
FULL ENJOY Call Girls In Mahipalpur Delhi Contact Us 8377877756
 

The development of a wireless LCP-based intracranial pressure sensor for traumatic brain injury patients

  • 1. International Journal of Electrical and Computer Engineering (IJECE) Vol. 10, No. 2, April 2020, pp. 1229~1238 ISSN: 2088-8708, DOI: 10.11591/ijece.v10i2.pp1229-1238  1229 Journal homepage: http://ijece.iaescore.com/index.php/IJECE The development of a wireless LCP-based intracranial pressure sensor for traumatic brain injury patients Preedipat Sattayasoonthorn1 , Jackrit Suthakorn2 , Sorayouth Chamnanvej, M.D3 1 Department of Biomedical Engineering, Mahidol University, Thailand 2 Center for Biomedical and Robotics Technology, Mahidol University, Thailand 3 Department of Surgery, Mahidol University, Thailand Article Info ABSTRACT Article history: Received Jun 10, 2019 Revised Oct 9, 2019 Accepted Oct 21, 2019 Raised intracranial pressure (ICP) in traumatic brain injury (TBI) patients can lead to death. ICP measurement is required to monitor the condition of a patient and to inform TBI treatment. This work presents a new wireless liquid crystal polymer (LCP) based ICP sensor. The sensor is designed with the purpose of measuring ICP and wirelessly transmitting the signal to an external monitoring unit. The sensor is minimally invasive and biocompatible due to the mechanical design and the use of LCP. A prototype sensor and associated wireless module are fabricated and tested to demonstrate the functionality and performance of the wireless LCP-based ICP sensor. Experimental results show that the wireless LCP-based ICP sensor can operate in the pressure range of 0 - 60.12 mmHg. Based on repeated measurements, the sensitivity of the sensor is found to be 25.62 µVmmHg-1, with a standard deviation of ± 1.16 µVmmHg-1. This work represents a significant step towards achieving a wireless, implantable, minimally invasive ICP monitoring strategy for TBI patients. Keywords: Finite Element Method Intracranial Pressure sensor LCP MEMS Fabrication Simulation Copyright © 2020 Institute of Advanced Engineering and Science. All rights reserved. Corresponding Author: Jackrit Suthakorn, Center for Biomedical and Robotics Technology, Faculty of Engineering, Mahidol University, 25/25 Puttamonthon 4 Road, Salaya, Nakorn Pathom 73170, Thailand. Email: jackrit.sut@mahidol.ac.th 1. INTRODUCTION Traumatic brain injury (TBI) patients require specialist care, especially concerning intracranial pressure (ICP) monitoring. Increased ICP leads to severe brain damage, the two major consequences are brain shift and brain ischemia [1-3]. An excessive ICP can cause disability or death to a patient. A normal ICP range is between 5 to 10 mmHg in adults, 3 to 7 mmHg in children and 1.5 to 6 mmHg in infants [4]. There are several techniques to measure and monitor ICP. Most conventional ICP measurement methods are invasive catheter-based procedures [5]. A number of clinical complications are encountered with catheter- based methods, such as infection and hemorrhage [6]. Additionally, patients with a catheter-based device are restricted to bed and lack mobility. A wireless minimally invasive ICP monitoring approach therefore is highly desirable to overcome the aforementioned limitations of catheter-based methods [7]. Most wireless ICP devices are designed to be an implantable system that is powered and can transfer data in order to minimize interference with the surrounding biological tissue and prevent the risk of infection. The design constraints are the size of device, the electrical supply of the device, and the device functionality [8]. There are two approaches to achieving a wireless implantable ICP sensor: the use of a passive sensor,or the use of an active sensor [8–10]. A passive sensor is a battery-free device, mostly they are based on inductive coupling which is suitable for small data packages. The principle of operation of
  • 2.  ISSN: 2088-8708 Int J Elec & Comp Eng, Vol. 10, No. 2, April 2020 : 1229 - 1238 1230 a passive ICP sensor is as follows: an off-body coil is placed at an inductively coupling distance from the implanted coil which is inside the patient’s head. A coupled magnetic field generates power to the sensor and transfers data from the sensor. The data is transferred from the sensor by changing the impedance of the implanted coil that is detected by the off-body coil. The passive sensor has a low operating frequency and a short workable distance due to the requirement for inductive coupling [11]. Recently, several groups of researchers have focused on this approach. For example, the recent United States Food and Drug Administration (FDA) approved ICP sensor, AURA™ ICP Monitoring System (Branchpoint Technologies, Irvine, CA, USA) is a battery-free wireless ICP sensor in the market [12]. The AURA™ sensor receives power inductively from the AURA™ Monitor (Model T0011B) through the AURA™ Antenna (Model T0010A). The sensor has a catheter tip with a strain-gauge pressure sensor that extends into the brain parenchyma to measure ICP. The measured data is transferred to the antenna which connects to a monitor. Data connection is via low energy Bluetooth. The dimensions of the sensor are 7 mm thickness x 21 mm diameter of body and 25 mm long, with a catheter diameter of 2 mm. This system has the advantage that the data receiver is provided to operate with other standard patient monitors. The monitoring duration is 29 days until the accuracy of the device shifts. In [13] a wirelessly powered passive implant using a piezoresistive pressure sensor (Amphenol P162 NovaSensor, Amphenol Advanced Sensor, Fremont, CA, USA) was developed to measure ICP. The system consists of two parts; the implant and external reader. Inductive coupling was applied to the design for power transmission. This study shows that sufficient power was generated to activate the sensor for monitoring the pressure in the range of 0 to 28 mmHg. In a later study [14] the researchers developed a data transmission unit using a far-field antenna. The system was evaluated in a simulated biological environment. The pressure was measured over the range of -3 to 33 mmHg and transmitted to the external receiver at a distance up to 1 m. In [15] the authors used a capacitive microelectromechanical system (MEMS) pressure sensor (Murata SCB10H-B012FB, Murata Electronics Oy, Vantaa, Finland) connecting to a 50 µm spiral coil to form an LC tank. The coil rests on the skull and connects to the MEMS sensor in the subdural through RF coaxial cable. An increasing pressure induces a change in resonant frequency in LC tank, the changes can be detected by an external reader antenna. The operating pressure is in the range of 0 to 70 mmHg. In [16] a passive ICP sensor is made from two planar coils facing each other to create an LC tank. The sensor is designed to be placed under the dura mater. When pressure is applied on the top membrane, the two coils move closer resulting in a change of resonant frequency. A wearable readout system was proposed to detect the pressure changes over a wide frequency range of 35 MHz – 2.7 GHz. The author suggested that this reader is suitable for variable designs of sensors. Passive sensors have three main limitations for ICP measurement, such as the bulky size of the coil, magnetic resonance imaging (MRI) incompatibility, and short operating distances. Active ICP sensors are battery-powered devices that contain the pressure sensor, data processing and wireless communication modules. This type of sensor allows the transmission of large data packages in shorter time periods over a longer distance and with better signal to noise ratio (SNR) than passive devices. There are two types of battery commonly use in implantable sensor; disposable and rechargeable. Rechargeable batteries are charged inductively from an external magnetic source. In [17] an analog wireless ICP sensor was developed using a capacitive MEMS pressure sensor (Murata Electronics Oy, Vantaa, Finland). The operating frequency is at the Industrial Scientific and Medical (ISM) band of 2.4 GHz. The change of pressure is detected by the sensor which modulates a 2.4 GHz RF oscillator. The output signal is coupled to a planar inverted - F antenna. The transmitted data is detected by the receiver held in close distance to the head. A 3-V 220 mAh lithium coin battery (CR2032, Panasonic, Secaucus, NJ, USA) supplies the power to all electrical components. The sensor’s performance was evaluated in both in-vitro and in-vivo experiments. In [18] the analog ICP sensor from [17] was implemented to be a digital device using a modified wireless development platform (eZ430-RF2500, Texas Instruments Incorporated, Dallas, TX, USA). The platform consists of a wireless radio (CC2500) and a microcontroller (MSP430) which connects to the capacitive MEMS sensor. When an increasing pressure is detected, the microcontroller measures the change in capacitance and sends the output through the wireless radio. The annular slot antenna is connected to the wireless radio to transmit the signal to the external readout unit. The size of the digital sensor is 22 mm width x 26 mm length x 10 mm thickness. The performance of the sensor was evaluated by measuring the dynamic ICP changes in a swine model. In [19] the authors proposed a wireless sensor that measures ICP indirectly via air pressure. The system consists of an implantable sensing device and a portable data recorder. In the implantable sensing device, an air pouch sits in contact with the cerebrospinal fluid (CSF) and converts liquid pressure into air
  • 3. Int J Elec & Comp Eng ISSN: 2088-8708  The development of a wireless LCP-based intracranial pressure sensor for … (Preedipat Sattayasoonthorn) 1231 pressure. The changes in air pressure are detected by an air pressure sensor that connects to the data processing and transmitting part. This system was fabricated into a 3.04 mm x 2 mm system on chip (SoC). This device uses 3 V 50 mAh battery and was tested in a hydrostatic environment. The operating pressure is in the range of -20 to 150 mmHg. The novelty of our work is to develop a biocompatible, implantable ICP sensor that is easy to fabricate with a low cost of manufacture that can operate during an MRI scan, none of the reviewed work above fully satisfy these requirements. In this work, a wireless LCP-based ICP sensor is proposed to measure the change of ICP for TBI patients. The sensor is designed to measure the ICP in the skull and transmit the data to an external monitoring unit. The design of the sensor consists of three main parts: the pressure sensing unit, the data transmission unit and the power unit. The pressure sensing unit is designed to be placed on the dura mater to detect the changes of ICP, while the data transmission and power units will be integrated into a platform and placed externally on the skull. The sensor is designed to be a complete LCP package. Due to LCP’s biocompatibility, it allows for a fully implantable device. The LCP-based pressure sensing unit is described in detail in our previous work [20, 21]. A piezoresistive concept was adopted to design the sensing unit to operate in the 0 to 50 mmHg pressure range. The LCP-based pressure sensing unit was fabricated using standard MEMS techniques and evaluated in a hydrostatic environment. The results showed an acceptable performance. The main contribution of the present work is the design and fabrication of an LCP-based ICP sensor that can measure and transmit the changes of ICP to the external unit wirelessly. Regarding to this study, the aforementioned LCP pressure sensing unit is connected to a newly developed data transmission and power units to demonstrate the functionality of the wireless LCP-based ICP sensor. The sensor performance is evaluated under a pressure range of 0 to 50 mmHg. Design details of the wireless LCP sensor are given in Section 3. The experimental setup for evaluating the wireless LCP sensor is given in Section 4. Experimental results and analysis are given in Section 5. 2. METHODOLOGY 2.1. Wireless LCP-based ICP sensor design overview The wireless LCP-based ICP sensor is designed to measure the change of ICP within the skull. The implantable sensor can detect the change of ICP and remotely transmit the data to the external monitoring unit through the scalp. The sensor structure consists of three main parts: the pressure sensing unit, the data transmission unit and the power unit as shown in Figure 1. The pressure sensing unit is designed to be placed under the skull to detect changes in ICP in the surrounding CSF. The data transmission and power units will be integrated into a platform and placed on the skull, underneath the scalp. When ICP increases, the pressure sensing unit measures the changes in pressure and sends the sensor output to the data transmission unit. The processed data is transmitted to the external monitoring device. The power unit supplies power to the pressure sensing unit and other electrical circuits on the data transmission and power platform as shown in Figure 1. The size of the pressure sensing unit is smaller than the platform. The overall size of wireless LCP-based ICP sensor can be minimized in future design iterations. The fabrication of the wireless LCP-based ICP sensor is designed to be biocompatible and implantable through the use of LCP. The pressure sensing unit was designed based on the piezoresistive concept and fabricated on an LCP membrane. The fabrication process and the characterization of LCP pressure sensing unit are described in [20]. LCP has high mechanical strength, low dielectric constant and various chemical resistance [22, 23]. It is suitable for packaging the data transmission and power unit. The data transmission unit is designed based on 2.4 GHz ISM bands. The data transmission unit uses Bluetooth communication to transmit data to the external monitoring unit, this design offers ease of interface and MRI compatibility [24]. The power unit presently requires a battery to supply power to the LCP pressure sensing unit and other circuits. An illustration of a conceptual design of the system is shown in Figure 2. Figure 1. Overall operating principle of the wireless LCP-based ICP sensor
  • 4.  ISSN: 2088-8708 Int J Elec & Comp Eng, Vol. 10, No. 2, April 2020 : 1229 - 1238 1232 Figure 2. Illustration of a conceptual design of the proposed wireless LCP-based ICP sensor 2.2 Wireless LCP-Based ICP Sensor Prototype The LCP pressure sensing unit contains four gold strain gauges with resistances between 449-535 Ω. The structure of this unit consists of an 8 mm x 8 mm x 100 µm outer membrane and a 2mm x 2mm x 50 µm sensing membrane above a bottom cavity. The outer membrane is bonded with a 10 x 10 mm x 100 µm LCP membrane to seal the bottom cavity using adhesive. The LCP pressure sensing unit is connected to the data transmission and power platform through ribbon cables. The platform of data transmission and power units consists of a Bluetooth to serial port module (HC-05), microcontroller (ATmega328/P, Atmel Corporation, USA), 16-bit analog-to-digital converter (ADC) (ADS 1115, Texas Instruments Incorporated, USA), Buck-Boost Converter (TPS63001, Texas Instruments Incorporated, USA) and 3.6 V lithium ion coin battery (LIR2450, 120 mAh, 24.5 mm diameter). These components are presently assembled on FR4 board, and the total dimension of the platform is 30 x 30 mm. Figure 3 shows the block diagram of the wireless LCP-based ICP sensor. The 3.6 V Li-on battery is used to power the LCP pressure sensing unit, ADC, microcontroller and Bluetooth module. The output voltage of the LCP pressure sensing unit is sent to the ADS 1115 and ATmega328/P controller respectively. The ADC resolution is 16 bits with full-scale range of ±1.024 V, which gives a resolution of 31.25 µV. The processed data is sent via serial communication to the HC-05 Bluetooth module. The HC-05 transmits data at 960 bps and 0 dBm RF transmit power (programmable up to +4dBm). The transmitted data is monitored with the serial monitor feature on Arduino 1.8.8 (Arduino, Somerville, USA). The prototype of the wireless LCP-based ICP sensor is shown in Figure 4. Figure 3. Block diagram of the wireless ICP measurement system
  • 5. Int J Elec & Comp Eng ISSN: 2088-8708  The development of a wireless LCP-based intracranial pressure sensor for … (Preedipat Sattayasoonthorn) 1233 Figure 4. Prototype of the wireless LCP-based ICP sensor 3. EXPERIMENT The wireless LCP-based ICP sensor is designed to operate in the pressure range of 0 to 50 mmHg. This experiment aims to mimic the pressures ranging from 0 to 50 mmHg in ambient conditions by using an MTS Insight Electromechnical Testing systems (MTS Systems Corporation, Minnesota, USA). Theoretically, the pressure (P) is generated by a force (F) acting over a surface area (A) that is in direct contact with the applied load. Applying this theory, the range of the force is calculated to correspond to the range of the pressure. In this case, P is the pressures ranging from 0 to 50 mmHg, and A is the 8 x 8 mm2 LCP sensing unit’s area. The range of the corresponding force is therefore 0 to 0.5 N. The MTS Insight system is set up for a compression test with a 100 N load cell and flat compression platens. TestWorks® software (MTS Systems Corporation, Minnesota, USA) is used to set up the input parameters and run the MTS Insight system on a personal computer. The parameters are the maximum force of 0.5 N, the test speed of 5 μm/s and the sampling rate of 1 Hz. A laptop is used to monitor the sensor output voltage that is measured and remotely transmitted on serial monitor. The clocks of these two computers are synchronized to correlate the time stamps. The overall measurement system is shown in Figure 5. Figure 5. The experiment set up for testing wireless implantable ICP sensor
  • 6.  ISSN: 2088-8708 Int J Elec & Comp Eng, Vol. 10, No. 2, April 2020 : 1229 - 1238 1234 The LCP pressure sensing unit is sandwiched between 5 mm thick silicone membranes. The silicone membranes act as cushions and distribute the pressure over the LCP pressure sensing unit. This sandwiched LCP pressure sensing unit is fixed on the compression platens as shown in Figure 6 (a) and (b). When the measurement starts, the serial monitor is run before starting the compression test on the MTS Insight system. The sensor output voltage is monitored and recorded on the serial monitor. When the MTS Insight system runs, the load applies the force ranging from 0 to 0.5 N at the testing speed of 5 μm/s. The forces are acquired in TestWorks® software at the sampling rate of 1 Hz. The applied load increases until the maximum force reaches the limitation at 0.5 N. The applied forces and the time stamps at the starting and ending points are recorded via the MTS Insight system. The time stamp at the starting point of the MTS Insight system is aligned to the time stamp of serial monitor to correlate the forces and the sensor output voltages. The sensor output voltages were recorded for ten repeated measurements with the same experimental conditions. (a) (b) Figure 6. The wireless LCP-based ICP sensor under the compression test (a) the sandwiched LCP sensing unit connecting to the data transmission and power platform (b) the LCP pressure sensing unit in between two silicone membranes on compression platens. 4. RESULTS The experiment was carried out to demonstrate the functionality and evaluate the performance of the wireless LCP-based ICP sensor. The sensor was subjected to loading and unloading conditions continuously. The recorded applied forces and the calculated pressures are plotted corresponding to time for ten repeated measurements as shown in Figure 7. From the graph, the pressure was applied from the base pressure (less than 1 mmHg) to the maximum pressure of 60.12 mmHg within approximately 412 seconds. The sensor output voltages of each measurement are recorded and plotted with respect to the pressure as shown in Figure 8. The output voltage linearly increases with increasing pressure. The sensitivity of the sensor is estimated from the slope of the best-fit line fitted to the data points for each repeated measurement, giving ten sensitivities. The average of these ten sensitivities over the pressure range of 0 to 60.12 mmHg is found to be 25.62 µVmmHg-1 ± 1.16 µV (average ± standard deviation) as shown in Figure 9. The graph shows that the output voltage at 0 mmHg is 0.951 ± 94.34 µV. The repeatability of the sensor is obtained from the standard deviation of the repeated measurements at the pressures of 0, 10, 20, 30, 40 and 50 mmHg and presented as error bars as shown in Figure 9. The graph shows small error bars which indicates that the wireless implantable ICP sensor demonstrates good repeatability. Figure 10 shows the residual of the best fit line of the sensor output voltage for all ten-measurement result. The residual captures the nonlinearity of the sensor alongside the measurement noise. There is no obvious structure to the residual plot which suggests the sensor output is very linear with respect to pressure, this is also supported by the R2 value of 0.984, where an R2 value of 1 would indicate a perfectly linear relationship. The standard deviation of the measurement noise evaluated from Figure 10 is found to be 47.75 µV which indicates the meaningful resolution of the sensor is approximately 2 mmHg. The resolution of the sensor is limited by noise in this experiment but the noise may originate from the MTS Insight system which generates a fluctuating output signal at low forces.
  • 7. Int J Elec & Comp Eng ISSN: 2088-8708  The development of a wireless LCP-based intracranial pressure sensor for … (Preedipat Sattayasoonthorn) 1235 Figure 7. Graph of recorded applied force and pressure for ten repeated measurements Figure 8. Graph of recorded sensor output voltage over the pressure range of 0 to 60.12 mmHg for ten repeated measurements Figure 9. Graph of averaged output voltages under 0, 10, 20, 30, 40 and 50 mmHg pressure range
  • 8.  ISSN: 2088-8708 Int J Elec & Comp Eng, Vol. 10, No. 2, April 2020 : 1229 - 1238 1236 Figure 10. Plot of the residual of the best fit line to the measurement result of the sensor output voltage for all ten repeated measurements. 5. DISCUSSION The goal of this work was to demonstrate the functionality and evaluate the performance of the developed wireless LCP-based ICP sensor. The experiment shows that the MEMS fabricated LCP pressure sensing unit can operate successfully in conjunction with the data transmission and power platform. The wireless LCP-based ICP sensor measured changes in pressure and transmitted the real-time data to the external monitoring device wirelessly. The sensor is able to measure the pressure from 0 to 60.12 mmHg which is higher than the maximum design pressure. As shown in Figure 8, the output voltage increases linearly pressure. The sensitivity of the wireless LCP-based ICP sensor obtained from the slope in Figure 9 is lower than the simulated sensitivity reported in our previous work [20]. In future work the LCP pressure sensing unit will be refabricated to enhance the sensitivity. The data transmission and power platform will be further minimized by removing the battery holder, upgrading Bluetooth module and ADCs and encapsulated in LCP for packaging. The power consumption of the system can be improved in a number of ways, for example, enhancing the resistivity of the strain gauges in the LCP pressure sensing unit, implementing the data transmission unit with a low energy Bluetooth module and developing a power controller to configure the work mode of the sensor. The size of the data transmission and power unit could be further reduced in future work by replacing the data transmission and power platform with wireless energy harvesting technologies [25, 26]. 6. CONCLUSION A wireless LCP-based ICP sensor was proposed in this work. This study proves the concept and demonstrates the functionality of a wireless LCP-based pressure sensor to monitor the changes of ICP for TBI patients. The proposed prototype consists of a MEMS fabricated LCP pressure sensing unit and a data transmission and power platform. The sensor achieved a measurement sensitivity of 25.62 µVmmHg-1 with the sampling rate of 1 sample per second over the range of 0 to 60.12 mmHg. Repeated measurements show close agreement which indicates a high level of repeatability of the sensor. This work shows that the proposed wireless LCP-based ICP sensor is able to operate in a pressure range of 0 to 50 mmHg which is within the requirement for ICP monitoring for TBI patients. ACKNOWLEDGEMENTS This research has been funded by FY2016 Thesis Grant for Doctoral Degree Student under National Research Council of Thailand (NRCT) through Mahidol University.
  • 9. Int J Elec & Comp Eng ISSN: 2088-8708  The development of a wireless LCP-based intracranial pressure sensor for … (Preedipat Sattayasoonthorn) 1237 REFERENCES [1] Kawoos U, McCarron RM, Auker CR, Chavko M., “Advances in intracranial pressure monitoring and its significance in managing traumatic brain injury,” International Journal of Molecular Sciences; vol. 16(12), pp. 28979–97, 2015. [2] Hyder AA, Wunderlich CA, Puvanachandra P, Gururaj G, Kobusingye OC. The impact of traumatic brain injuries: a global perspective. NeuroRehabilitation, vol. 22(5), pp. 341–53, 2007. [Online]. Available from: http://www.ncbi.nlm.nih.gov/pubmed/18162698 [3] Schwarzbold M, Diaz A, Martins ET, Rufino A, Amante LN, Thais ME, et al., “Psychiatric disorders and traumatic brain injury,” Neuropsychiatric Disease and Treatment, vol. 4(4), pp. 797–816, 2008. [4] Roytowski D, Figaji A., “Raised intracranial pressure: What it is and how to recognise it,” Continuing Medical Education, vol. 31(11), pp. 390–5, 2013. [Online]. Available from: http://www.cmej.org.za/index.php/cmej/article/view/2909/3284. [5] Harary M, Dolmans RGF, Gormley WB. Intracranial pressure monitoring—review and avenues for development. Sensors (Switzerland), vol. 18(2), pp. 3–7, 2018. [6] Zhong J, Dujovny M, Park HK, Perez E, Perlin AR, Diaz FG. Advances in ICP monitoring techniques. Neurological Research, vol. 25(4), pp. 339–50, 2003. [Online]. Available from: http://www.tandfonline.com/doi/full/10.1179/016164103101201661 [7] Khan M, Shallwani H, Khan M, Shamim M., “Noninvasive monitoring intracranial pressure – A review of available modalities,” Surgical Neurology International, vol. 8(1), p. 51, 2017. [Online]. Available from: http://surgicalneurologyint.com/surgicalint-articles/noninvasive-monitoring-intracranial-pressure- a-review-of-available-modalities/ [8] Bashirullah R., “Wireless implants,” IEEE Microwave Magazine, vol. 11(7 SUPPL.), pp. 14–23, 2010. [9] Yu L, Kim BJ, Meng E., “Chronically implanted pressure sensors: Challenges and state of the field,” Sensors (Switzerland), vol. 14(11), pp. 20620–44, 2014. [10] Hodgins D, Bertsch A, Post N, Frischholz M, Volckaerts B, Spensley J, et al., “Healthy aims: Developing new medical implants and diagnostic equipment,” IEEE Pervasive Computing, vol. 7(1), pp. 14–20, 2008. [11] Joung YH., “Development of implantable medical devices: From an engineering perspective,” International Neurourology Journal, vol. 17(3), pp. 98–106, 2013. [12] Mapato M, Klysuban P, Kulworawanichpong T, Chomnawang N., “Metal-embedded SU-8 slab techniques for low-resistance micromachined inductors,” International Journal of Electrical and Computer Engineering, vol. 8(6), pp. 4772–80, 2018. [13] Khan MWA, Björninen T, Sydänheimo L, Ukkonen L., “Remotely Powered Piezoresistive Pressure Sensor: Toward Wireless Monitoring of Intracranial Pressure,” IEEE Microwave and Wireless Components Letters, vol. 26(7), pp. 549–51, 2016. [14] Khan MWA, Sydänheimo L, Ukkonen L, Björninen T., “Inductively Powered Pressure Sensing System Integrating a Far-Field Data Transmitter for Monitoring of Intracranial Pressure,” IEEE Sensors Journal, vol. 17(7), pp. 2191–7, 2017. [15] Behfar MH, Björninen T, Moradi E, Sydänheimo L, Ukkonen L. Biotelemetric Wireless Intracranial Pressure Monitoring: An In Vitro Study. International Journal of Antennas and Propagation, vol. 1–10, 2015. [16] Wang F, Zhang X, Shokoueinejad M, Iskandar BJ, Medow JE, Webster JG., “A Novel Intracranial Pressure Readout Circuit for Passive Wireless LC Sensor,” IEEE Transactions on Biomedical Circuits and Systems, vol. 11(5), pp. 1123–32, 2017. [17] Cabello-ruiz R, Tecpoyotl-torres M, Jácome AT, Vera-dimas G, Koshevaya S, Vargas-chable P., “Displacement mechanical amplifiers designed on poly-silicon,” International Journal of Electrical and Computer Engineering (IJECE), vol. 9(2), pp. 894–901, 2019. [18] Meng X, Browne KD, Huang SM, Mietus C, Cullen DK, Tofighi MR, et al., “Dynamic evaluation of a digital wireless intracranial pressure sensor for the assessment of traumatic brain injury in a swine model,” IEEE Transactions on Microwave Theory and Techniques, vol. 61(1), pp. 316–25, 2013. [19] Jiang H, Guo Y, Wu Z, Zhang C, Jia W, Wang Z., “Implantable Wireless Intracranial Pressure Monitoring Based on Air Pressure Sensing,” IEEE Transactions on Biomedical Circuits and Systems, vol. 12(5), pp. 1076–87, 2018. [20] Sattayasoonthorn P, Suthakorn J, Chamnanvej S., “On the feasibility of a liquid crystal polymer pressure sensor for intracranial pressure measurement,” Biomedical Engineering/Biomedizinische Technik, Mar 15. 2019, [Online]. Available from: http://www.degruyter.com/view/j/bmte.ahead-of- print/bmt-2018-0029/bmt-2018-0029.xml
  • 10.  ISSN: 2088-8708 Int J Elec & Comp Eng, Vol. 10, No. 2, April 2020 : 1229 - 1238 1238 [21] Sattayasoonthorn P, Suthakorn J, Chamnanvej S, Miao J, Kottapalli AGP., “LCP MEMS implantable pressure sensor for Intracranial Pressure measurement LCP MEMS implantable pressure sensor for Intracranial Pressure measurement,” In: The 7th IEEE International Conference on Nano/Molecular Medicine and Engineering IEEE, p. 63–7, 2013. [Online]. Available from: http://ieeexplore.ieee.org/document/6766317/ [22] Wang X, Engel J, Liu C., “Liquid crystal polymer for MEMS: Processes and applications. Journal of Micromechanics and Microengineering; vol. 13, pp. 628–633, 2003. [Online]. Available from: http://www.iop.org/EJ/abstract/0960-1317/13/5/314. [23] Bouneb I, Kerrour F., “Nanometric modelization of gas structure, multidimensional using comsol software,” International Journal of Electrical and Computer Engineering, vol. 8(4), pp. 2014–20, 2018. [24] Vogt C, Reber J, Waltisberg D, Buthe L, Marjanovic J, Munzenrieder N, et al. “A wearable bluetooth le sensor for patient monitoring during MRI scans,” Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBS. 2016 pp. 4975–8, Oct 2016. [25] Stephen NG., “On energy harvesting from ambient vibration,” Journal of Sound and Vibration, vol. 293(1–2), pp. 409–25, 2006. [26] Nanda A, Karami MA. “Energy harvesting from arterial blood pressure for powering embedded micro sensors in human brain,” Journal of Applied Physics, vol. 121(12), 2017.