SMARTER HEALTH:SENSORS

Fred Ziecina

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Smarter Health - Instrumentation• Overview of human-body sensors

• Focus on wearable, continuously recoding sensors• Not lab, major imaging (MRI, CT)• Not exhaustive – very broad field, rapidly advancing

• Sensors and sensor technology• Communications• Data collection and storage• Issues

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Sensors and Sensing Devices• Sensor - A device that measures or detects a

real-world condition, such as motion, heat, or light and converts the condition into an analog or digital representation

• Sensing device – A group of subsystems that use one or more sensors to provide measures of conditions

• For this discussion, we will be discussing sensing devices but the terms will be used interchangeably

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Physical Measures• Motion

• Body movement, inertia, joint position

• Mechanical properties• Pressure and flow rate of fluid or gas• Temperature• Weight

• Chemical properties• Blood oxygen and glucose• Sweat pH and electrolyte concentration

• Electrical activity• Electrocardiogram (ECG)• Electroencephalogram (EEG)• Electromyogram (EMG)

• Sound• Images

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Sensor Technologies• Pervasive consumer technologies

• Accelerometers• Gyroscopes• Light and imaging, high resolution cameras• Microphones• Proximity and motion sensors• Location - Global Positioning Systems (GPS)*

• Medical specific technologies• Electrical activity

• ECG/EEG/EMG• Bio-impedance

• Pressure • Flow• Temperature

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Smart Helmets

• Riddell – Head Impact Telemetry System (HITS)• Monitors and records every significant head impact • On-board electronics measure and record location,

magnitude, duration, and direction of head impacts

• Upload and evaluate each occurrence on computer• Send warnings to sideline coaches• Upload data to medical centers for real-time analysis6

© 2011 IBM Corporation

Building a smarter planet

© 2011 IBM Corporation

NFL Combines - Under Amour G39

• Biometric (Smart) shirt with embedded sensors

• Measures:– Heart rate– Breathing Rate– Skin Temperature– Accelerometer (G-Force)

• Embedded hard drive/Transmitter

• Upload to a computer using Zepher software to analyze the athlete's individual movements and biometric data

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Smart Clothing• Post-stroke physical rehabilitation - Laboratory for

Biomedical Informatics, Department of Computer Engineering and Systems Science University of Pavia (Italy)• Patient wears garment embedded kinesthetic

sensors connected wirelessly to a computer• Computer detects in real time whether the patient is

performing the exercises correctly or not, and provides feedback through y visual representation on the screen

• University of Minnesota – Lucy Dunne• Working to embed sensors into regular clothing• http://www.youtube.com/watch?v=y4HBZ-ggUG8

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Athletic Monitor• Garmin Edge 705• Wirelessly monitors

• Heart rate• Cadence• Power generation• Uses ANT protocol

• GPS and barometric altimeter• Speed, distance, elevation,

course, ….• Upload and analyze rides on

computer

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GrandCare System• Integrated monitoring

system• Activity and wellness

information is accessible by caregiver

• Customized alerts• Includes entertainment

and socialization capabilities

• Produced by GrandCare Systems LLC, West Bend, WI

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GrandCare System

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GrandCare – Rule Based Actions• Sensors: motion, door, bed sensors, alert/action buttons, blood pressure

device, weight scale, temperature (indoor/outdoor), lighting control, CallerID modem

• Can graph data daily, weekly, monthly and identify trends• Does excessive motion indicate a problem?

• Sleeping pattern

• Rules and actions:• If NO motion in kitchen from 8am to noon, email daughter.• If ANY motion at foot of bed at night, turn on bathroom light.• If EXCESSIVE motion in bathroom for more than 45 minutes between 10p and

6am, then contact Emergency Call List.• If WANDERING motion detected in the home, then call daughter.• If door OPENED from 10pm to 6am, call neighbor• If nobody IN BED for more than 45 minutes between 10pm and 6am, text

night nurse (got up and didn’t return to bed)• If weight increases by more than 5 pounds in 2 days, call caregiver. • If blood pressure is not taken, show message on GrandCare TouchScreen “Dad,

It’s Time To Take Your Blood Pressure”.• If inside temperature is less than 65, text maintenance guy.• If unknown person calls, email daughter-in-law.

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Wireless Data Collection

• A&D Bluetooth Blood Pressure Monitor

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• BC-590BT Wireless Body Composition Monitor• Bluetooth• Compatible with

Microsoft's HealthVault

Wireless Data Collection

• MyGlucoHealth Meter• Blood Glucose Meter• Uploads reading to website

via Bluetooth and Smartphone

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• NatureSpirit® • Fingertip Pulse Oximeter • Uploads reading via

Bluetooth

TRANSDERMAL CONTINUOUS GLUCOSE MONITORING

• Symphony tCGM - Biochemical glucose sensor• Adheres to the skin• Sends continuous blood glucose

readings to a handheld wireless device

• Prelude SkinPrep• Removes skin and hair• Passes electric pulses into the skin

and senses when it has reached live underlying skin cells

• Will also be used for transdermal drug delivery

• Echo Therapeutics 15

Smart Pill

• Sensors and microprocessor chip attached to pill• Fully digestible• Stomach acid activates it• Data received by patch

on skin which relays data via Bluetooth to smartphone

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• Developed by Proteus Biomedical, soon to be distributed by Novartis AG

• Initial use to collect biometric data in organ in transplant patients to monitor drug timing and dosage

Smart Clothing

• Biotex – European research project

• Develop intelligent fabrics with embedded sensors

• Remotely monitor vital signs as well as body fluids

• First biochemical use will monitor sweat pH, salinity and perspiration rate

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Remote Oxygen Sensing• University of Regensburg, Germany

• Photograph patch on skin to determine O2 level• Inexpensive sensing film containing two dyes• Emit light at frequencies to match the red and

green channels of digital camera when exposed to purple light

• Amount of light from red dye depends on oxygen level

• Amount of light from green dye is constant• Illuminate with purple LED flash• Current response time 2-10 seconds

• Sensor film could be placed on skin to reveal areas of low oxygen concentration where a tumor could be developing 18

Food Portions – Image Sensing• Meal Snap by Daily Burn

• iPhone App• Identifies food and

estimates calories• Tracks meals

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• NTT • Working with

University of Tokyo

• Estimates calories• Suggests foods for

next to stay under calorie target

Robot Pills• Endoscopic Imaging Robot - colonoscopy• Remotely controlled

• Can move in any direction• 11.1 mm diameter, 27 mm long

• Scuola Superiore Sant'Anna—CRIM Lab (Italy), Vanderbilt University, Italian Institute of Technology Network (Italy)

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Sleep Monitor – Audio Sensing• Sleeping U

• iPhone App• Monitors and records sleep using

audio• Provides longer term, low cost, at

home sleep monitoring• Disclaimer:

• “Sleeping U does not claim to be, nor intends to be, a medical or clinical application”

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• SleepSound• Android App by Preventice• Monitors and records sleep using

audio• Provides longer term, low cost, at

home sleep monitoring

MONITORED AUTOMATIC PILL DISPENSER

• MAPD hands out pills on a strict schedule• Verbally reminds

patient to take pills, getting more insistent

• Requires button press• Calls caregiver if pills

not taken within 20 minutes

• One month supply, calls caregiver if supply is running low

• Produced by Philips22

Heart-powered Nanogenerator• Research at Georgia Institute of Technology

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• Zinc-oxide nanowires deposited on a flexible polymer substrate

• 2 mm by 5 mm device sealed in a polymer to shield it from body

• Attached with adhesive to rat heart

• Generated 30 picoamps at 3 millivolts• Expect to scale up output to power implantable

nanosensors• Blood pressure or glucose sensors• Have modest power requirements and don't need a

continuous supply

Smartphone Sensors• Common data capture capabilities

• Accelerometer• Compass• Gyroscope• Camera – imaging• Microphone – audio• Location – GPS

• Common communication• Cellular• WiFi• Bluetooth

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Device Design Considerations• Physical size • Computing power needs• Data storage • Sensor capabilities• Wireless communications • Frequency and size of data transmissions• Battery type and life• User interface • Receiver of the data• Cost

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Cost Tradeoffs

Data Storage

Computing Power

Battery Capacity

Miniaturization

Cost

Sensing Capabilities

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Data Tradeoffs

Communication Frequency

Power Consumption

Computing Demand

Sensing/Sampling Frequency

Amount of Data

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Data Frequency and Sampling• User driven individual measures

• Blood pressure, weight, glucose

• Periodic measures• Very low frequency sampling• Fluid retention changes

• Continuous monitoring• High frequency sampling• ECG, EEG, Oxygen saturation

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Achieving Balance is Key• Sampling frequency tends to drive data

storage, communication and battery needs

• Communication tends to have largest impact on power consumption

• Communication options could be limited by the devices that will consume the data

• Battery solutions and cost play the largest roles when trying to make a device small

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Data Communications• What will the device communicate with?

• Internet or cloud based machine• Dedicated PC• Mobile phone• Other sensors

• How much data will be sent and received?• Bursts of small amounts of data• Regular or continuous transfer• Onboard logic for smart data selection

• How secure does connecting and transmitting need to be?• Device requires authentication• Compression and encryption

• What protocol will be used?

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Communications Comparison Summary

  ZigBee ANT Bluetooth WiFi 802.11b

Data capacity (Kbps):

250 1,000 1,000 11,000+

Range (meters): 70 10 100

Battery life Years Years Days Hours

Nodes per network

255 - 65,000 80 8 30

Software size (Kbytes):

4 - 32 250 1,000+

Cell Phone Support

No No Yes Yes

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WiFi – 802.11Good Bad

Good for devices and sensors used in a fixed location that communicate with PCs, smart phones or internet connected devices

Significant power consumption when compared to alternatives

Provides communication over longer distances than Bluetooth or ZigBee

Limited options for communicating while mobile, potentially requiring more data storage to stage information

Allows several options for security Requires significant intelligence and overhead for managing a connection (i.e. large code footprint)

Easy for general end users to understand and configure

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Bluetooth

Good Bad

Good for devices and sensors that will communicate with mobile phones or PCs

Short range for communication

Allows options for secure connection and transmission

Limited number of nodes allowed

Low power options becoming more standard

Better than ZigBee for large data transfers

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ZigBee

Good Bad

Good for devices and sensors that communicate with other sensors or PCs

Not supported by most cell phones

Allows options for secure connection and transmission

Not as good as Bluetooth for large amounts of data

Consumes less power than WiFi or Bluetooth

Allows longer range communication than Bluetooth

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ANT

Good Bad

Good for devices and sensors that communicate with other sensors or PCs

Not supported by most cell phones

Allows options for secure connection and transmission

Most available devices do not fully leverage security features

Consumes less power than WiFi, Bluetooth or ZigBee

Better than ZigBee for large data transfers

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SmartPhone as the Host Device• Mobile and personal

• 42% of teens can text blindfolded

• 173M smartphones sold in 2008 -> 298M sold in 2010

• 31M people viewed mobile ads in 2008

• >27% now have only mobile no land line

• 2013 US mobile market > 100% per capita

• Capable of significant processing and staging data

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Mobile Medical Home

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Alternative Host Devices• PCs• Home hubs

• Plug Computers• Tablet devices• Set-top boxes

• TVs

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Medical Body Area Networks• MBANs are the future

• Still need more low-power sensors• Still need dedicated wireless spectrum – can’t afford

interference• Also called Mobile Body Area Networks

• Some players• GE Healthcare• Phillips Healthcare• Intelesens• Realtime Technologies

• FCC has gotten public comment and is working on rules• Decision expected this year

• IEEE 802.15.4 working group• Subgroup of Wireless Personal Area Networks (802.15)

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Standards and Data Interchange• Continua

Industry alliance establishing a system of interoperable personal connected health solutions

http://www.continuaalliance.org

• IEEE 11073 Health informatics - Medical / health device communication standards

http://standards.ieee.org

• HL7Health Level Seven International (HL7) is the global authority on standards for interoperability of health information technology

http://www.hl7.org)

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Case Study: bodyguardian• Developed by Preventice in

Rochester

• Long term, unobtrusive cardiac monitoring to promote mobility and independence

• Focused on emerging epidemics• Atrial fibrillation• Congestive heart failure• Obstructive sleep apnea

• Integration of physiological signals

• Ensure system non-proprietary, adaptable, integrated 41

Bodygardian System• Sensing device communicates to:

• PCs and Android-based smartphones using Bluetooth

• Smartphone is the user’s primary user interface device

• Host device provides• User interface• Data staging and storage• Analysis logic • Data transmission to the cloud

environment

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Measures• Activity level using a 3 axis accelerometer

• Formula to derive a relative measure of activity• Value calculated every 10 seconds

• ECG• Sampled at either 128 or 256 samples per second• Transmitted at least once every 3 hours

• Heart rate derived from an ECG• Average calculated every 10 seconds

• Respiration rate determined using bio-impedance to measure breathing• Average calculated every 60 seconds

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ECG Interpretation

• Low and high thresholds• Segment distances and

variability• Correlation between

sensor measures

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• Remotely configurable thresholds to support clinical logic• ECG noise elimination• Triggers or markers for noteworthy events

bodyguardian Challenges• Weight and size• Battery life• Signal processing and interpretation• Communication flexibility

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Sensors - Conclusion• Sensors are becoming very small and inexpensive

• All sorts of body information can be sensed• Basis for pervasive and continual health monitoring

• Networks are everywhere• Easy to collect and move data

• Power is an issue but sensors are using less and creative sources are being explored

• Major issues:• Huge amount of data can be collected

• Data transmission (power consumption) and storage• Human review• Requires intelligent outboard filtering

• What do we do with the data?

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Big Picture Activities• National Institute of Standards and Technology (NIST)

Initiatives• Medical Device Interoperability• Body Area Networks & Pervasive Health Monitoring• Content-based Access to Electronic Health Records• Long-term Data Preservation and Management of

Electronic Health Records• Image Quality for Healthcare Applications• http://www.nist.gov/healthcare/emerging/

• CHIRON - Cyclic and person-centric Health management: Integrated appRoach for hOme, mobile and clinical eNvironments• European Research Project• http://www.chiron-project.eu/

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