Technology fundamentals

CONTENTS
6 Building the body area network
17 Industry alliance tackles technical, policy challenges 29
22 European project helps manage broken hearts
at home
27 Medical imaging makeover
24
29 Data acquisition systems allow stop-action cardiac
imaging in one scan
33 Managing digital imaging’s mountains of data 27
38 Mixed-signal, embedded open doors
for digital imaging
43 Automated blood test is a breeze “This digital edition was designed to play on
most browsers using Adobe Flash 8.0 or
47 Camera in a pill surveys GI tract higher. Should you encounter any difficulties
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60 Inside the art of pulse oximetry
2 E E T i m e s |The diagnosis for medical electronics | D e c e m b e r 7 , 2 0 0 9

Opinion

Technology fundamental to reform
By George Leopold

or for blocking “fundamental reform” of a

O
nce the political posturing,
demagoguery and horse trad- system that accounts from anywhere be-
ing cease, it’s far from clear tween one-fifth to one-sixth of the U.S.
whether Americans will actu- economy, depending on which Senate floor
ally achieve health care re- speech you choose to believe.
form. The guess here is that, in This is indeed a sad state of affairs, but
time-honored Washington fashion, all sides not wholly unexpected, given the political
in this noisy, high-stakes debate will claim and economic stakes for the health care
political victory while condemning the other industrial complex.
side either for effecting a “government Assuming Congress approves health
takeover” of the U.S. health care system care legislation this year and President

3 EE Times |The diagnosis for medical electronics | December 7, 2009

Opinion

Barack Obama signs it
into law, a key question
in implementing re-
forms is what role tech-
nology can play in
reducing skyrocketing
medical bills.
Up to now, many diag-
nostic technologies
have greatly improved
U.S. health care while
saving countless lives.
Those technologies re-
main expensive, how-
ever, making it awfully
tempting for a medical
specialist to order
another high-ticket
test—which may or
may not be needed—
Music: Cross Douglas Road by Patrick O’Rourke, www.patrickorourke.com


Opinion

as a way to pay off the huge up- forms. One office worker left to take care system, but it is a critical tool
front investment in the latest med- a job at Starbucks, where she could in the fight to put patients ahead of
ical equipment. get the medical benefits the doctor profits and politics. p
If we are to reduce medical costs, could not afford to provide.
such practices must stop. It is physicians like this one who About the Author
George Leopold is news director for
Part of the problem with soaring desperately need technology’s help EE Times.
health care costs is that medical to survive and, perhaps one day,
email: gleopold@techinsights.com
school graduates confront huge thrive. For technology companies that
tuition bills that drive them into have created the senior position of
lucrative specialty medicine and chief medical officer, a huge opportu-
away from general practice. nity exists to customize existing tech-
One of the best stories we’ve nologies to serve these medical
seen during the health care debate professionals and not just the spe-
focused on a general practitioner cialists whose offices are already
who was struggling to meet the filled with the latest diagnostic tools.
needs of her community and keep None of us is getting any younger,
her practice afloat amid a ceaseless and some of us are facing life-and-
tide of health insurance paperwork. death medical decisions about our
The MD could barely afford to em- aging parents. Technology alone
ploy file clerks to handle the flood of won’t heal what ails the U.S. health


Body area nets

Building the body area network
By Rick Merritt

neering at the University of Washington,

N
etworked medical devices hold
the promise of more-effective notes that much of that spending was for
and lower-cost health care, as costly hospital care, often delivered long
services traditionally delivered after the onset of chronic problems that
in clinical settings become could have been better managed early on.
accessible in the home. The rationale be- A critical component of the solution “is
hind the shift is sound, but the business, in embedded or wearable devices linked to
regulatory and technical hurdles are many. therapy,” said Joseph Smith, vice president
The problem is clear: The United States of emerging technologies at Johnson &
last year spent an estimated $2.5 trillion—
Wearable devices and implants could
18 percent of its GDP—on health care.
Yong-Min Kim, a professor of electrical engi-
help cure what ails health care


Health care, American style
High costs are due in part to late-stage treatments, administered with expensive equipment in hospital settings

$2.5 trillion Johnson Services Inc. (New
Amount spent domestically each year on health care Brunswick, N.J.), which oversees
18% dozens of medical businesses.
Portion of U.S. GDP spent on health care “We don’t yet have the treatment
45% paradigms for continuous care for
U.S. share of world health care spending in dollars
chronic diseases, but I think we will
45-50 million get there,” Smith said in September
Number of uninsured Americans
at the IEEE Engineering in Medicine
66% and Biology Society’s annual confer-
Percentage of Americans who are overweight
ence (EMBC).
65 million “We all have a responsibility to
Number of Americans with chronic heart problems
be involved in health care reform,”
20 million: Rebecca Bergman, a vice president
Number of Americans with diabetes
of new therapies at Medtronic (Min-
100,000 neapolis), said at EMBC. “Tech is
Number of people who die in the U.S. each year from preventable treatment errors
not at the core of this issue, but we
One hour should make tech part of the solu-
Amount of time spent on paperwork for each hour of health care delivered in the U.S.
tion and not part of the problem.”
50% A group from Australia reported
Amount of U.S. health care dollars typically spent in the last six months of a patient’s life
Sources: Yong-Min Kim, University of Washington; Joseph Smith, vice president of emerging technologies at at the conference on a program
Johnson & Johnson Services Inc.; EE Times


Body area nets

that remotely monitored former car- Mir Imran, who in the mid-1980s de- Business hurdles
diac patients participating in an ex- veloped one of the first implantable It’s easy to think of ways to extend
ercise program. The program, cardiac defibrillators. “I’m thinking today’s wealth of consumer and
developed in conjunction with Nokia, about clinical problems and optimiz- computer technologies to medical
helped reduce the number of pa- ing solutions for them, and leverag- applications. What’s harder is mak-
tients readmitted to hospitals from ing electronics heavily—whether for ing such concepts reliable enough
the typical 28 percent to 8 percent. drug delivery or new kinds of im- to earn the trust of the doctors who
Such efforts are fueling interest in plants, or putting sensors where they would use them, the regulators who
a rising tide of networked medical have never been, for example in a
devices and services. “I’m in the hip or knee replacement.”
thick of it,” said serial entrepreneur In one project, Imran is working
with Texas Instruments to equip

R
R The body electric

Julien Penders, a
cardiac stents with an RFID tag, a
microelectromechanical system
(MEMS) flow sensor and a tiny radio
to report on the flow of blood
program manager for
body area network through the passage. The goal is an
technologies at IMEC
(Leuven, Belgium), early warning system for the nearly
offers a primer on 7 percent of stents that become
BANs and wearable
devices. blocked over time.
Click image to launch video


Body area nets

would approve them and the insurers geared for their special needs. But “if Analyst Stephan Ohr, who co-
who would pay for them. a couple of [medical electronics] ven- authored a recent Gartner report on
Jonathan Collins, principal analyst dors solidify around a particular wire- telemedicine, noted that “today, a
at ABI Research, predicts the use of less spec, it won’t need to be a nurse comes to your home, takes
wearable consumer fitness devices [standard on the scale of] Bluetooth,” your blood pressure and transmits
will grow rapidly over the next few Collins noted. the reading to a remote doctor using
years as the devices adopt standards EEG
Body Area Network for health
like Bluetooth. By contrast, devices
& comfort monitoring Vision Hearing
for professional clinical use in hospi-
tals and homes will take longer to Positioning
adopt proprietary technologies ECG
Glucose Blood pressure

R
R
POTS
Heart and home
Network DNA
protein
Philips describes how Cellular Toxins
a variety of home
sensors could work
with cell phones and
TVs to allow remote WLAN
monitoring of patients’
cardiac conditions. Implants
Source: IMEC

9 EE Times |The diagnosis for medical electronics | December 7,

Body area nets

an Internet connection, but more- care systems and services. By the ance providers. Despite the many
automated patient monitoring using end of 2008, as many as 600,000 experiments, “the business models
wireless is still 10 years out. The of the estimated 2.5 million im- in place today just do not get it
biggest reason is that doctors don’t planted devices in use were linked to done,” LaLonde said. “I contend we
trust [the new devices]—they really home systems that transmitted data are in a race to the bottom, in
don’t know what to do with the automatically to clinics for remote which investment drives up expec-
data—and insurance companies monitoring. But none of the compa- tations and more investment with-
won’t pay for them.” nies providing those remote services out capturing value.”
Indeed, the biggest challenge may is being adequately compensated
be getting someone to pay for home for them, said John LaLonde, vice
president of R&D for Boston Scien-

R
R Not just a Band-Aid
Bandages one day
could integrate
tific’s pacemaker group, which has
150,000 implant users on its re-
mote monitoring service.
Some companies sell the remote
active
components services bundled into the cost of the
that stimulate implants, LaLonde said; others
the skin to
speed healing, then lease the home devices and sell the
let you know when services outright, and a few have se-
they are ready to be
Click image to launch video removed. cured reimbursement from insur-


Body area nets

R
R Dialysis untethered

By 2014, startup
Nanodialysis
Global shipment forecasts for wireless body sensors:
2009 vs. 2014
Units (millions)

Segment 2009 2014 CAGR
(Eindhoven, (’09 –’14)
Netherlands) hopes
to field a wearable Sports and fitness 10.42 180.55 76.91%
system for patients
with kidney failure, In-home health
eliminating regular
trips to the hospital.
management 0.35 59.41 179.31%

There are technical issues, too. For
Hospital/clinic-based 0.88 180.48 189.95%
monitors
example, making sure that digital
health records can be read by any Total 11.65 420.44 104.87%
system in a way that’s both secure Source: ABI research

and bandwidth-stingy is “a monumen- skin, but few users will fuss with the “That’s the big problem, and so far
tal task involving many disciplines, gels. So researchers are working on researchers are just scratching the
and it’s going to take 10 years to re- a class of dry sensors that could be surface of it,” said Lindsay Brown, a
solve,” said entrepreneur Imran. worn in clothing, reliably detecting body area networking specialist at
As for hardware, today’s monitor- microvolt-level biosignals while filter- IMEC (Leuven, Belgium).
ing devices often require conductive ing out the noise that comes from Engineers at Analog Devices Inc.
gels to make good contact with the brushing against skin and cloth. are combining capacitive converters


Body area nets

R
R Watch your step

Sensors that clip
on to shoes could
A low-energy Bluetooth variant de-

will be ratified in December. Compa-
nies including CSR, Nordic Semi-
ical Implant Communications Service
signed to work on button-cell devices (MICS) band, a 402- to 405-MHz snip-
pet of spectrum approved in the mid-
1990s for communications with
monitor the gait of
conductor and Texas Instruments external programmers and gateways.
people who have
difficulty walking, are testing chips for it. An IEEE The FCC approved 1-MHz sidebands
helping to prevent
802.15.6 standard for BANs, mean- for MICS in March that developers
debilitating falls.
while, is in an early stage of defini- such as Saurin Shah of Medtronic will
tion. The FCC could rule before the support in next-generation chip sets
and a ring of electrodes in a design
end of the year on a request from GE for various uses, including one-way
that could enable better sensors as
Healthcare to allow a Wi-Fi variant for links between external devices.
well as touch-sensitive surfaces. ADI
BANs in the 2,360- to 2,400-MHz “The jury is still out on [which
is also working on ways to inject a
band. ZigBee is yet another player wireless approach will be] the win-
signal into the body to measure im-
with its own health care profile. ner,” said Karthik Vasanth, product
pedance, for gauging fat content or
The Continua Health Alliance, an line manager for the medical busi-
even for modeling the dynamics of
ad hoc industry group promoting ness unit at Texas Instruments.
the skin, said Paul Errico, a strategic
home care systems and services, Multiple wireless links will proba-
marketing manager with ADI’s con-
has blessed both Bluetooth and bly coexist in tomorrow’s BANs,
sumer health segment.
ZigBee to date. and all of them will likely have to be
Another issue is which wireless
Implants are already using the Med- tooled or retooled to meet medical
technologies BANs should ride.


Body area nets

R
R Night patrol

A wireless monitor
Tapping into the brain
Neural stimulators open new directions for implants beyond the heart
worn at home can
check for sleep apnea Now that implants are a well- this tipping point,” said company acquired in 2005 by
with as much accuracy established therapy for a Christopher Chavez, who St. Jude Medical. That group
as the more-complex
handful of heart conditions, heads a neuromodulation will see its business in neural
and more-expensive
medical electronics compa-
systems now used only
in clinics.
applications’ unique requirements.
At EMBC, a Shenzhen, China, re-
nies are working on a host of
new devices and uses for
them. Many of the efforts are
R Videos
R
search institute showed a modified focused on the brain.
802.15.4 media access controller A growing body of research
using simplified protocols to en- suggests that well-targeted
hance sensor node battery life. And electrical stimulation of
Qualcomm showed a compressed nerves can generate positive Tim Denison, a senior engineering Mir Imran gives a tour of his design
manager at Medtronic in Minneapolis, for the first implanted cardiac defibril-
sensing algorithm that reduces the results across a broad range shows a prototype for an implant that lator, approved by the FDA in 1985
amount of data acquired and sent of conditions, from addiction listens to brain waves and stimulates and now used by thousands. Now a
neurons to test for a variety of ailments. serial entrepreneur, Imran is helping
on a BAN using any radio. Thus far, to epilepsy, Parkinson’s See the full story at: to establish a foundry for implants.
the company has applied it to blood disease and depression. “I www.eetimes.com/showArticle.jhtml;?
articleID=219500873"
pressure and heart rate sensors. p think we are on the verge of

13 EE Times |The diagnosis for medical electronics

Body area nets

implants rise from $24 mil- eight uses for neural stimula- declining number of smokers some kinds of pain and de-
lion in 2000 to an estimated tors thus far. “We believe and rising use of stents to generative diseases,” said
$320 million this year, each one is less than 10 per- lessen need for heart im- Richard Kuntz, chief science
Chavez said. Industrywide, cent penetrated in its target plants. By contrast, more than officer at Medtronic.
neural implants represent application, and 10 new uses a third of global health issues Earlier this year, Medtronic
about a $2 billion business are still waiting to be ap- are neurological in nature, a said it had begun animal tri-
today, growing at double-digit proved,” Chavez said. percentage that is expected to als of a closed-loop system
rates to about $3.9 billion in The shift comes at a good expand as people live longer. to listen and respond to brain
2014, he estimated. time for implant makers, Pacemaker giant Medtronic waves automatically.
The U.S. Food and Drug which are expecting the already has devices for ail- Neural stimulators have
Administration has approved ments like Parkinson’s and been shown to be effective in
Neural stimulators are “has a pipeline [of neural im- tests, though much of the un-
plants in development for] derlying brain science remains
effective in tests, but
OCD [obsessive-compulsive a mystery. For example, de-
much of the underlying disorder, depression, epilepsy, pressed patients who did not
science is a mystery migraine, fecal incontinence, respond to shock therapy can


Body area nets

be shown smiling in videos when with tissues taught to beat on their
stimulated by a neural implant. own,” said Joseph Smith, vice pres-
“It’s a little eerie,” said Kuntz.
The future ident of emerging technologies at
“We really don’t know how it works, belongs to Johnson & Johnson Services Inc.
because we are talking about genetic (New Brunswick, N.J.).
some of the most complicated But a more immediate task for
therapies,
physiology of the body.” companies such as Medtronic lies
Jonathan Sackner-Bernstein, an
some in shrinking the size of today’s
associate center director at the researchers 10-cc cardiac implants, eliminating
FDA, took a contrarian position in argue the electronic leads that are the
one of several forums on deep cause of most failures.
brain stimulation at an IEEE bio- “We believe it is possible to get
engineering conference in Septem- tions in genetic therapies. this device down to 1 cc in size
ber. “You still have to have brain Indeed, the long-term future be- without a lead, so the device itself
surgery [to have an implant in- longs to biological treatments, is in the heart,” said Rebecca
stalled], and I am not sure many many researchers believe. For ex- Bergman, a vice president of new
people would want to have a scar ample, “we need to think different therapies at Medtronic. “We hope
across their skull,” he said, calling and make a cell a genetically con- [to have such prototypes] in
instead for more radical innova- trolled, programmable pacemaker, animals to define those issues


Body area nets

in the near future.” designed by an expanding set of
Others see further directions ‘The next sometimes small companies and
for implants. revolution startups. Today most implants are
“The next big revolution will be will be made by large, vertically integrated
implantable, closed-loop drug companies, such as Medtronic and
closed-
delivery systems,” said Mir Imran, St. Jude Medical, that control most
who developed one of the first loop aspects of the design.
implantable cardiac defibrillators. drug “If you develop an implant today,
“There are therapeutic proteins delivery you have to go to a dozen manufac-
and peptides available, but they turers to put it all together,” Imran
systems’
have to be delivered directly into said. “You end up spending three
the brain because the stomach as an artificial pancreas for dia- times as long and 10 times as
chews them up.” betes, Imran said. much money to get the result you
Such devices will eliminate side Imran is working on as many as should.” — Rick Merritt
effects when drugs are delivered to five different implant concepts
the entire body. Closed-loop sys- today. He also acquired Modulus About the Author
tems that can sense the need for a (San Jose), an implant maker, to Rick Merritt is editor at large
of EE Times.
drug and deliver a proper dosage bolster its role as a foundry for
will be key to breakthroughs such devices that he believes will be email: rmerritt@techinsights.com


Telehealth

Industry alliance tackles
technical, policy challenges
By Dylan McGrath

to transmit their vital signs seam-

I
nformation technology is already
used today to exchange health- lessly to the health care profes-
related information, but proponents sionals monitoring their status.
of the nascent telehealth concept Such technology, they argue, would
see an opportunity to do far more. improve the quality of care while
They envision a world in which elderly requiring fewer face-to-face doctor
patients and others with chronic health visits, thereby increasing the effi-
problems use connected medical devices ciency of health care delivery and


Telehealth

containing its cost. a sea change in how they conduct adoption of telehealth solutions is
Before that vision can be realized business. the lack of open, standards-based
on a grand scale, however, there are According to Rick Cnossen, direc- architectures.
technical, regulatory and cultural tor of personal health enabling for Cnossen, who is also president
hurdles to clear, including getting Intel’s Digital Health Group, an and chairman of the Continua
health care professionals to accept immediate obstacle to widespread Health Alliance, believes telehealth

The making of an implant
Although the market for internal medical devices is expanding rapidly, the process for making implants
still relies heavily on painstaking manual labor

Welcome to the foundry Small hybrids Ties that bond
Mir Imran, developer of one of the first Imran describes the unique (hybrid, dense Wire bonding is one of the methods used to
implantable defibrillators, opened the doors and flexible) printed-circuit boards used deliver dense boards for implants.
of his Silicon Valley company Modulus to in implants.
show how implants are made.
Click images to launch video


Telehealth

will not achieve its potential unless terfaces and revolutionized the way than 200 member companies, span-
devices are based on nonproprietary computers communicate with pe- ning the gamut from tech heavy-
protocols and are interoperable. ripheral devices. weights like IBM, Intel and Samsung
“We’ve seen this [interoperability The Continua Health Alliance is Electronics to powerful health insur-
scenario] play out time and time a nonprofit industry coalition dedi- ance firms such as Aetna Inc. and
again,” said Cnossen. He pointed to cated to establishing a system of Kaiser Permanente Inc.
the standardization effort around interoperable, connected personal Continua includes technical work-
the Universal Serial Bus, which dis- health products. The organization, ing groups that evaluate existing
placed a plethora of proprietary in- established in 2006, now has more

Some assembly required In the can
Technicians attach a battery and lead The pc board is then folded and inserted
wires to each implant by hand. into a titanium container.



Telehealth

standards and work with standards have achieved certification.
bodies such as the IEEE and ISO to Cnossen said he expects the
bridge gaps on the road to interop- pace of certifications to pick up a
erable telehealth solutions. Con- bit “now that we’ve got the ball
tinua’s policy working groups lobby rolling.” The alliance is currently

Laser welding governments with an eye toward working on version two of its
influencing legislation. guidelines.
In one of the few automated processes in
the final assembly stage, a laser welder Taking a page from the playbook Continua’s initial thrust has heav-
seals the titanium can.
of the Wi-Fi Alliance, Continua has ily focused on the technical as-
also established a rigorous test pects of creating interoperability
and certification program to ensure between devices, Cnossen said,
that products bearing the Continua but lately there has been a shift
logo are fully interoperable. toward more focus on the organiza-
In February, Continua announced tion’s policy activities.
it had completed the first version In the United States, that effort
A plastic hat
of its design guidelines, developed consists primarily of pushing for
A plastic header is fitted onto the can,
forming a seal that also shields the lead for device manufacturers that in- more reimbursement for telehealth
wires that attach to the body. tend to put their products through services from Medicare and Medic-
the Continua certification process. aid. Similar lobbying efforts are
Since then, a total of eight products under way in other regions, notably


Telehealth

Europe and Japan, Cnossen said. Another hurdle that telehealth technology, Cnossen said. “They
Telehealth is taking off, Cnossen must clear, however, is getting doc- know this is happening. They want
said, but it would grow more quickly tors to buy in. With demands on their to work with the industry.” p
if government programs reimbursed time rising for training and other ac-
providers for more services. “Gov- tivities, physicians are wary of how About the Author
Dylan McGrath is West Coast online
ernments can be a little slow to much effort might be required to editor at EE Times.
change,” he said. “They like to see a accumulate and monitor the poten- email: dmcgrath@techinsights.com
lot of data.” tially voluminous data generated by
But with the debate currently connected healthcare devices.
raging in Washington over U.S. Software that manages the flow of
health care reform, and with a new information and provides high-level
political party in power in Japan for analysis is therefore required,
the first time in decades, this is a Cnossen said.
time when Continua’s policy efforts Regulatory bodies that approve
could have an impact, according medical equipment for disease
to Cnossen. monitoring, such as the U.S. Food
“In the U.S., we have a great op- and Drug Administration are also
portunity over the next six months cautious, he said.
that could be very positive for tele- Continua has had preliminary dis-
health legislation,” he said. cussions with the FDA about the


HeartCycle

European project helps manage
broken hearts at home
By Peter Clarke

mix of hardware and software built

A
HeartCycle aims to create a closed-loop
into everyday items such as cloth- feedback system to help cardiac patients
ing and bedding could let cardiac monitor their conditions without numerous
patients manage their health at visits to their physicians. The system
home under the European Union’s would report automatically to clinicians so
HeartCycle project. The four-year collabora- that if changes needed to be made in the
tive research effort is part of a wider push treatment protocol or in the patient’s
to find innovative ways to deliver health lifestyle, that information could be con-
care more effectively—and at lower cost— veyed over a computer network.
as Europe’s population grays. While face-to-face consultations are


HeartCycle

more personal, the monitoring en- Measurements, detection, prediction
abled by systems such as Heart-
Cycle could alert patients and clini- Important
cians quickly to small changes in a decision point!
patient’s condition that might not
otherwise be spotted until they be-
Telemedicine

Analysis, decisions
came serious problems. Such sys-
tems would complement face- platform
(e.g. MOTIVA)
to-face visits, though ideally the lat- “At home”/Patient
ter would be required less often— platform “At home” Medical
and would less often take place Patient (e.g. MyHeart) healthcare professionals
under dire circumstances.
The HeartCycle project launched
on March 1, 2008, and has a budget Value is created
of 22 million euros (about $33 mil- by closing the loop!
lion), with the EU providing about 14
million euros (about $21 million).
The work is led by Philips Research
(Aachen, Germany) and involves 17
other academic and industry groups, Therapy, feedback
including Clothing Plus Oy (Kankaan-
paa, Finland), Koninklijke Philips
The HeartCycle closed-loop management approach comprises two loops.
Electronics NV (Amsterdam, Nether-
lands) and Medtronics Iberica SA


HeartCycle

(Madrid, Spain).
Developing “the next generation of
telemonitoring systems requires a
multidisciplinary approach” that in-
volves more than just bridging exist-
ing islands of automation and
networking, said HeartCycle project
coordinator Harald Reiter, who is
based at Philips Research. “Defi-
nitely, the project is based on inno-
vation,” Reiter said. “If you just try Bio-impedence monitor.
to use the existing technology, it is
not enough.”
To that end, the project targets the
“domestication” of a number of sen-
Matsense sensor
sor types and equipment. Some of
the technology is in use now in hos-
foil for the Smartbed
pitals but is being customized for system.
home use; other work involves novel
sensors.
One technology is a bio-impe-
dence monitor (BIM), used to meas-
ure the presence of fluid in the
tissues. BIM systems can be used


HeartCycle

to predict decompensation, or the is the MatSense foil, a bed-sized
inability of the heart to maintain ad- pressure sensor on which the pa-
A vest with
equate circulation. tient sleeps. Composed of an array
Frequent home bio-impedence of capacitive sensors, it can provide textile
measurement can open up the pre- both ballistocardiogram and move- electrodes
diction window for decompensation ment signals. is one
from only one or two days (via sim- Specific algorithms are being element of
ple blood-pressure measurement) to developed to calculate heartbeat the in-home
two weeks, according to Heartcycle intervals, respiration cycle and bio-impedance
documentation. “This allows treating movement. The technology can be monitor.
the patient at home, and the hospi- used to monitor sleep quality,
tal is avoided,” said Reiter. as a change in sleep patterns could
The challenge is to remake bulky
hospital equipment so that patients
The goal is a daily measurement procedure
can manage the gear in a home set-
ting. Toward that end, electronic tex-
that takes only 15 minutes. Use of the vest
tile developer Clothing Plus is ensures that electrodes are positioned the
working on a measurement vest that same way on the body each time the test
would let patients easily position is run. The measurement is started via an
electrodes in the correct place for interfacing PDA and runs automatically.
testing and might have to be worn
for only 10 minutes a day.
Another sensor within the program


HeartCycle

presage the need for an in-person Thus far, the EU project has under- The Clothing
exam or a change in medication. taken extensive consultation to Plus-designed vest
The flow of data and intelligence develop the usage cases and the should need to be
across networks and around the requirements for equipment and worn for only a few
system is a key aspect of the Heart- software. Preparatory work has also
minutes a day.
Cycle project. For example, auto- begun for a program of clinical trials.
mated systems are needed to All of the equipment must be CE
monitor the data, extract useful in- certified for medical device use, and
formation and alert professionals at that requires planning.
appropriate times. A longer-term goal is to include
“There are not enough nurses to data from implanted devices such
be looking at the data all the time,” as pacemakers, although that work
said Reiter. “This is our main focus. is still in the conceptual stage,
“While the networks for communi- Reiter said.
cation will be ZigBee, Bluetooth, Clinical trials of HeartCycle tech-
USB and so on, the algorithms to nology are due to start in March
alert the nurses [must be devel- 2011 and could take six months to
oped]; this is our major work.” one year to complete.
Successful completion “would The Smartbed, based on the MatSense foil,
About the Author mark the end of the project, but captures a person’s vital signs—including heart
Peter Clarke is European news before that we will have pretrials to rate, breathing rate and sleep quality—during the
director for EE Times.
test and justify certain elements, night in an unobtrusive way, without the need to
email: pclarke@techinsights.com including sensors and electronics,” glue electrodes to the skin.
said Reiter. p


Digital imagi ng

Medical imaging makeover
By Nicolas Mokhoff

igital medical imaging is an en-

D
standards had to be established. The
abler for the anticipated adop- Medical Imaging & Technology Alliance,
tion of electronic medical a division of the National Electrical Manu-
records by health care providers facturers Association, is the collective
industrywide, replacing analog voice of medical imaging equipment devel-
films—which must be carried by hand from opers and manufacturers. One of the
one health care provider to the next—with group’s goals is expanded global accept-
digital bits that are acquired, processed, ance of the Digital Imaging and Communi-
seamlessly streamed to multiple locations cation in Medicine standard. DICOM allows
via wired and wireless transmission, and digital imaging technologies to interact
archived electronically for ready
retrieval.
Films carried by hand are giving way
For it all to work as envisioned, to bits seamlessly streamed

Digital imagi ng

seamlessly, so imaging results can Analog Devices’ Scott Pavlik de- sheer volume. Samplify’s answer is a
be shared among all the parties re- tails what he calls the most cutting- solution whose signal compression
sponsible for a patient’s care, with edge technology for heart imaging in ratios provide reductions in data ac-
an eye toward effecting the best the emergency room: CT scanners quisition rates from 2:1 up to 3:1.
course of treatment. with data acquisition systems that Allowing the raw data to be readily
Radiology began as a medical sub- can enable stop-action imaging of a repurposed avoids the need to repeat
specialty in the first decade of the beating heart in one scan. The costly medical imaging procedures.
1900s, after the discovery of X-rays. equipment produces a complete Texas Instruments’ Suribhotla
For the first 50 years of radiology, image in just one rotation around (Raja) Rajasekhar addresses the
the primary examination involved the body, completing the scan so trends and challenges affecting the
creating an image by focusing X-rays quickly that the heart does not move electronics for various imaging
through the body part of interest appreciably during the procedure. In modalities, including digital X-ray,
and directly onto a single piece this way, the scan does not need to ultrasound, CT scan and MRI. Digital
of film inside a special cassette. be synchronized with the period be- imaging in the 21st century, Ra-
Digital imaging techniques emerged tween heartbeats. jasekhar notes, promises superior
in the 1970s with the first clinical Samplify’s Allan Evans and Al diagnostic capability, image archiv-
use and acceptance of the com- Wegener observe that the sharing of ing and on-demand image retrieval
puted tomography (CT) scanner. medical imaging data among health anytime, anywhere. p
In the three contributed articles care providers requires portability
that follow, authors from Analog De- not only of the reconstructed images About the Author
vices, Samplify and Texas Instru- but also of the raw data used to re- Nicolas Mokhoff is research editor
of EE Times.
ments touch upon the main issues construct the images. The challenge
that make digital medical images in archiving such data in the context email: nmokhoff@techinsights.com
such powerful diagnostic tools. of electronic medical records is its


Signal acqui s i t i on

Data acquisition systems allow
stop-action cardiac imaging in one scan
By Scott Pavlik

he most cutting-edge technology

T
during the procedure; therefore, the proce-
for heart imaging in the emer- dure does not need to be synchronized
gency room is a computed to- with the period between heartbeats.
mography (CT) scanner that can If this can be achieved, the patient does
provide a high-quality image of a not need to go through the extensive prep
patient’s heart with one scan and very little of having an ECG (electrocardiogram) at-
prep time. Two factors are key to achieving tached and monitored to pinpoint the exact
this: The CT scanner can do the entire time between beats when the heart is still.
image in one rotational scan around the The resultant time savings enables a quick
body, and the scanner is fast enough so diagnosis and saves costs.
that the heart does not move appreciably To get a complete, accurate image in one



revolution, a 256-slice scan must be Those specs lead to a system that diode. The photodiode current (I) is
done, for a sufficient horizontal reso- needs 256,000 channels of fast, converted to voltage (V) through a
lution of about 0.5 mm. To achieve accurate data acquisition. Each low noise I-V amplifier/integrator.
sufficient radial resolution, about channel includes a crystal scintilla- The I-V channels are then multiplexed
1,000 scanning channels are used. tor that converts X-ray energy into through a 24-bit, 128-channel A/D
light, which is detected by a photo- converter, and the digital outputs are
fed to the signal processor to pro-
Single slice vs. Multi slice vide the decoded CT image.
Analog Devices Inc.’s ADAS1128
24-bit, 128-channel A/D converter
packs this capability into a 10 x

Detector array
CrystalScintillators
convert X-rays to light,
followed by photo diodes
that generate current
proportional to light and
Linear pixel vs. Grid area pixel X-ray intensity, which is
detector array detector array measured by Current-to-digital
(1 pixel by Y pixels) (X pixel by Y pixels) converters
Data Acquisition Systems (ADCs)
1,000 AFE signal chains per slice



10-mm mini-BGA using 4.5 Ultrasonic the moving particles can be used
Frequency and/or
mW/channel. The total power Transducer phase of reflected
to calculate the particle, or flow,
sound changes with
for the data acquisition section velocity. With a finely focused ul-
speed/direction
is then just over 1 kW for a of blood flow
trasound beam, the velocity can
256-slice system, enabling a be plotted across the width of
better than 50 percent power the blood vessel to determine
reduction over typical equip- uniformity of blood flow. If the ve-
ment of comparable complexity. locity plot is the classic parabola,
Overall power is further re- then there is smooth, laminar
duced by the improved speed. flow; a distorted pattern would
Applications include dynamic reveal obstructions or structural
imaging, to observe the heart problems in the vessel.
or other organs in motion. The use of a pulse ultrasound
waveform provides additional in-
Finding blood flow anomalies formation by measuring transit
The blood delivery system has A CW signal or pulse is sent into the blood time to provide a map of a given
two major components: the stream and reflected back from the cells. vessel. While the technique can
heart and the vascular system be valuable for diagnosing and
of arteries, veins and capillaries. uous wave (CW) signal, usually a locating vascular disease, it will also
Doppler ultrasound imaging systems sine wave, or pulse into the blood become increasingly useful for diag-
can be used to determine blood flow stream which is reflected back from nosing traumatic injury and stroke.
rates as well as identify blockages, the blood cells. As in all Doppler sys- The pulse ultrasound image can be
restrictions or leaks. tems, the change in frequency result- used to find stoppage or leakage in
Doppler ultrasound sends a contin- ing from the wave’s interaction with the flow pattern.



Ultrasound signal acquisition is at- Doppler ultrasound enables fast point-of-care diagnosis
tenuated by the square-of-the-dis- of vascular anomalies that can lead to disease
tance law, both in transmission and
in reflection, leading to the need to Stroke
•Progressive blockage of brain arteries (ischemic)
handle a dynamic signal range ap- •Rupture or aneurysm (hemorrhagic)
proaching 160 dB. One development Carotid artery blockage
•Progressive blockage of arteries to brain
that provided ultrasound systems •Most common cause of paralyzing strokes
with the accuracy and discrimination Heart disease
•No. 1 cause of death in the U.S.
needed to provide clear images was
a combined low-noise amplifier and Abdominal aortic aneurysm (AAA)
•Tenth leading cause of death in men 50+
I&Q demodulator or phase shifter •700,000 undiagnosed in U.S.
developed by Analog Devices. The
concepts have been expanded to
yield the AD9276/77.
Ultrasound designers can now de-
velop smaller systems for use in
point-of-care applications. p
Peripheral artery disease
•Poor circulation in the legs
About the Author •Can cause serious disability
•Can lead to amputation
Scott Pavlik is worldwide strategic •20% of people 70+ have PAD
marketing manager for Analog
Devices’ Healthcare Group. He holds
a BSEE from Clarkson University.

email: scott.pavlik@analog.com


Data Compres s i on

Managing digital imaging’s
mountains of data
By Allan Evans and Al Wegener

t no time has digital imaging been

A
only for archiving of final images created
more important to medical imag- by medical imaging technologies, but also
ing applications than in today’s cli- for storage of the raw data from which
mate of health care reform. those images are formed. In an environ-
Indeed, the current U.S. economic ment where medical records are trans-
stimulus program calls for $19 billion in ferrable from one health care provider
funding to facilitate health care providers’ to another, portability of the raw data en-
adoption of electronic medical records. ables that data to be repurposed for dif-
Such a move will drive up demand not ferent end uses and thereby avoids the


Data Compres s i on

need to repeat costly medical imag- data from a single CT scan can be Among the imaging modalities,
ing procedures. reused to form volumetric images CT scans could benefit the most
Among the imaging modalities, that can support multiple end uses.
from raw-data portability
computed tomography may stand to For example, when the X-ray data
benefit the most from raw-data from the scan is first captured, gen-
portability to support multiple end erally an image is reconstructed to ogist may retrospectively recon-
uses. First, CT scans are expensive, support an initial diagnosis by the struct new volumetric images using
running in excess of $1,000 per attending radiologist. If a second different back-projection algorithms
scan, second only to MRI. Second, opinion is required, a second radiol- to highlight certain anatomical

Click either image for correct answer


Data Compres s i on

Click either image for correct answer

features. If the diagnosis requires CT image data captured in digital CT image data captured in
surgical intervention, the surgeon form becomes portable across digital form becomes portable
may utilize the CT data to plan a health care providers, enabling the
across health care providers
laparoscopic or endoscopic proce- patient to seek the provider who can
dure. Finally, the CT data might be provide the greatest probability of a
used a fourth time, as registration successful outcome, without having bility of medical imaging data among
of the anatomical features to to pay each provider to repeat the health care providers requires not
guide the surgeon during the surgi- costly scans. just portability of the reconstructed
cal procedure. As we have just illustrated, porta- images, but also portability of the


Data Compres s i on

X-ray or sonogram data used to re- Signal compression holds the authors challenge the readers to
construct the images. The challenge promise for enabling portability pick which image was formed from
for archiving this data in the context raw data and which one from com-
of medical imaging data
of electronic medical records is its pressed data.
sheer volume. Samplify has performed similar
A modern CT machine captures greatly exceeds the time to repeat studies with ultrasound OEMs, using
X-ray data at a rate of 1 Gbyte/ the scan. images formed from pre- and post-
second, resulting in 30 Gbytes for a Signal compression represents a beamformed data at compression
30-second scan. Ultrasound can promising solution to the problem of ratios of up to 3:1. Another image
generate similar volumes of data, portability of medical imaging data.
with each frame composed of hun- In a paper presented at the SPIE
dreds of scan lines that themselves Medical Imaging Conference in Feb-
are composed of thousands of sam- ruary, Samplify Systems, GE Health-
ples. At 30 frames per second, ultra- care and Stanford University
sound data acquisition can exceed demonstrated the efficacy of signal
20 Mbytes/s and result in data sets compression, in both lossless and
on the order of 10 Gbytes for scans near-lossless modes, to achieve
lasting a few minutes. compression ratios that provide
The size of these data sets can be compelling reductions in data acqui-
a limitation to their portability if they sition rates, from 2:1 up to 3:11. A
cannot be easily provided on a stor- set of images accompanying this ar-
age medium to the patient, or if the ticle (page 34) presents one of the
time to transmit them from one image pairs used in the survey that
health care provider to another was highlighted in the SPIE paper;


Data Compres s i on

set accompanying this article (page promise of reducing health care bedded in the data acquisition
35) repeats the image comparison, costs by increasing the portability silicon without added cost relative to
but with ultrasound images. Again, of medical imaging data and there- that of existing A/D converters built
the authors challenge the readers by reducing the need for duplicate on legacy processes. p
to find any differences—and this scans. References
time we have even made it easier Moreover, signal compression can 1Wegener A., Chandra N., Ling Y., Senzig R.,
Herfkens R. 2009. Real-time compression of raw
by showing wire phantoms. provide this benefit while actually computed tomography data: Technology, architec-
By providing a 75 percent reduc- decreasing the cost of medical ture and benefits. Proceedings of the SPIE Medical
Imaging Conference, Vol. 7258 (March).
tion in the storage or transmission imaging equipment, by reducing data http://tiny.cc/6Nemt
requirements for medical imaging acquisition times.
data, signal compression makes the In CT machines, faster data ac-
data portable by enabling the data quisition rates result in lower costs
sets to be provided to the patient on for mechanical rotary joints or slip
low-cost dual-layer DVDs or by reduc- rings as well as for the RAID drives
ing the transmission time for send- used to buffer the data prior to
ing the data sets from one provider image reconstruction.
to another. Similarly, signal compression in
Signal compression provides the ultrasound machines reduces I/O
bottlenecks between the analog
About the Authors front end and the digital signal
Allan Evans is vice president of marketing processing elements.
at Samplify Systems Inc.
Signal compression can be em-
Al Wegener is Samplify founder and CTO.

email: AEvans@samplify.com; AWegener@samplify.com


M ixed-signa l apps

Mixed-signal, embedded
open doors for digital imaging
By Suribhotla (Raja) Rajasekhar

igital imaging in the 21st cen-

D
ties in imaging systems, leading to tremen-
tury comes with the promise of dous advancements in medical imaging. At
superior diagnostic capability, the same time, embedded processors
image archiving and on-demand have dramatically increased the capabili-
retrieval anytime, anywhere. ties for medical image processing and real-
Since the advent of digital techniques for time image display for faster and more
medical imaging in the early 1970s, digital accurate diagnosis.
imaging has grown significantly in impor- The convergence of these technolo-
tance. Recent advances in design capabili- gies, coupled with emerging standards for
ties for mixed-signal semiconductors offer electronic health records, is providing the
unprecedented electronics packing densi- impetus for better patient care.


Technology fundamentals

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