1. Portable personal RFID databases
for AAL-enabled healthcare
environments.
Ignacio Díaz-de-Sarralde, Diego López-de-
Ipiña, Xabier Laiseca, Sergio Blanco
DeustoTech – Deusto Institute of Technology
Avda. Universidades 24, 48007, Bilbao, SPAIN
{isarralde,dipina,xabier.laiseca,sergio.blanco}@deusto.es
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2. Contents
• Introduction
• Objectives
• Related Work
• An NFC-supported platform:
• RFID tags as portable databases
• Relaying care data in the real-time web world
• Conclusion
• Further questions
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3. Introduction
• Technology:
– RFID is mainly used as a low-cost solution to uniquely identify objects.
• RFID tags encode a URI from where an object’s data can be accessed and operated
(Data-on-network approach)
• However, passive HF RFID tags allow significant data storage (up to 4K), enabling
immediate access to the desired object’s metadata.
• Domain:
– AAL aims to increase our quality of life and autonomy and to reduce
the need for being institutionalised or aiding it when it happens
– Healthcare and Elderly care centres are challenging environments
from the data gathering and publishing perspective.
• Solution:
– A hybrid approach where a data on tag approach is used in order to
gather lifelogs of residents, occasionally contacting a back-end in order
to synchronize or enrich said stored data.
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4. Objectives
• This work has a two-fold objective:
1. Experimental: Evaluate how much data can
actually be stored in HF RFID tags
2. Practical: Combine the RFID data-on-tag
approach with NFC to improve data
management in a healthcare centre,
where:
• RFID tags can serve as temporary repositories of care
events
• Interactions between residents’ RFID wristbands and
staff’s NFC mobiles can improve care data
management and keep relatives up-to-date
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5. Related Work
• NFC technology operating on 13.56MHz combines the
functionality of a RFID reader device and a RFID
transponder into one integrated circuit
– NFC read/write mode allows NFC devices to access data from
an object with an embedded RFID tag
• The combination of NFC technology and RFID tags has
been used in the last few years in several research
projects related to medicine and caretaking
– However, so far RFID applications have not incorporated
custom data directly onto RFID tags
• Still prevails a generic lack of standardization, only
alleviated by initiatives such as the Continua Health
Alliance
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6. A Platform to Enhance Care
Data Management
• Caretaking is a suitable domain for combining NFC
technology and the RFID data-on-tag approach in
order to enhance the data gathering process
– The ill and elderly people are looked after at different
domains (patient’s homes or their families’, residences,
hospitals) and by different people (relatives or staff),
making very difficult to reconcile the information
gathered
• Some issues:
– Residents do not always stay and sleep at the same
place
– Data capture is not highly prioritised
– IT support at care centres and family homes is diverse
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7. Features
• Supports caretaker on structured patient data
recollection and storage
• Allows collected data to be used efficiently
– By enabling easy and clean data writing and
reading of RFID tags with NFC phones
– By relying patient activity to relatives via external
services
• Research novel RFID applications in daily use
– Uses HF RFID tags as embeddable and portable DBs
– Proposes optimal data encoding and compression
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8. RFID Tags as Portable
Databases
• The NFC Forum specifies a data-
packaging format called NDEF (NFC
Data Exchange Format) to exchange
information between an NFC device
and another NFC device or an NFC tag
• Evaluation of HF RFID tags as tools to
store data:
1. Select a set of easily wearable
tags (ISO 15693-compatible) with
as much storage capacity as
possible and still compatible with
NFC
2. Identify the maximum number of
useful bytes storable in the selected
tags
3. Develop a new efficient mechanism to
store data on HF RFID tags
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9. Storage Capabilities of a 4K
Mifare Watch
Mifare 4K Watch
Actual bytes
Number of stored Average writing written (record ID of
Record Size (bytes) records time (ms) 4 bytes)
1 372 8081 1860
2 335 7724 2010
4 279 7259 2232
8 209 6846 2508
16 139 6520 2780
32 83 6283 2988
64 46 6252 3128
128 24 6093 3168
3196 1 6214 3200
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10. Efficient Recording of Data in HF
RFID Tags
• Evaluating storage capabilities, it
was decided that only one record
NDEF messages should be used
– No standard on the data structures
used by care centres to keep data on
their interns was found
– Therefore, we have developed our data
structures and encoding mechanisms:
• Patient metadata is enriched with lifelog
message entries detailing concrete
events in said patient’s medical history.
• Range Encoding Compression is applied
to said data structure.
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11. ElderCare Care Log
Encoding
• ElderCare proposes a special purpose compressed serialization
method in order to maximize the usage of HF RFID tags’ storage:
– Raw data (Stringified) – human readable string representation of a
lifelog.
– Encoded – transformation of a stringified care log into a more optimal
representation.
– Serialized data– it is a byte representation of a care log
– Compressed data – applies a Range Encoding compression algorithm
to the byte representation.
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13. An NFC-supported
Platform
Features:
Allows for anywhere at any time, asynchronous
multi-user gathering of data
Allows for asynchronous care data reporting to
both internal and external services
Integrated components
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15. Relaying care data in the
real-time web world.
• The ElderCare AAL platform does
not only keep custom data to
enhance the daily activities in a
care centre but ...
– It also allows exporting part
of that data to external
services (such as Twitter, e-
mail, SMS, RSS feeds...)
• Relatives and friends can follow
the lifelog of residents.
• Digital copies of a patient’s
medical history and reports can
be sent by e-mail.
• ...
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16. Conclusion
• ElderCare stores a log for every new care procedure applied on the
resident’s RFID wristband, following a data-on-tag approach
– It uses RFID tags as mini databases
• ElderCare makes data stay at any time with the resident and be
available in real-time and without relying on wireless links
– Our experiments show that the storage capacity of 1K (wristband) or 4K
(watch) Mifare RFID tags, aided by CareTwitter’s custom-built data
serialization format, is sufficient for storing the care logs of a
whole day
• The integration of ElderCare with external services (such as Twitter) proves
the high potential of using interactions with everyday objects or
people to automatically publish data into Internet
– The lifelog of a resident is available to authorized users
– Detailed reports can be automatically sent without additional efforts
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