Wearable sensor Technology

1. Wearable sensor Technology Bonato & Chan

2. Overview • Describe clinical need for wearable sensors • Discuss sensor functionality • Present technical aspects of sensor/system implementation (e-textile and wireless) • Provide specific examples of sensors/systems developed by European groups • Gloves • Shirts • Bed linen

3. Motivation • Health Care Reform (Independence at Home Medical Practice Demonstration Program) • electronic health information systems, remote monitoring, and mobile diagnostic technology • Less intrusive patient monitoring • Improve diagnoses • Enhance safety • Increase community participation • Maintain independence

4. Motivation • Community Based research • Take the gait lab out of the hospital • Measure research phenotyping • Medication titration • N of 1 trials

5. European commission Peter Wintlev-Jensen and Andreas Lymberis

6. Motivation Percentage of GDP (EU27) Source: EC '2009 Ageing Report: economic and budgetary projections for the EU-27 Member States (2008-2060)'

7. Motivation Framework Programme 7 ICT research ICT & Aging • Advanced Prototypes for independent living/active aging (Ambient Intelligence, Robotics) • Open Systems, Reference Architectures, Platforms • Support: roadmaps, ethics, standards, Int’l cooperation Currently~30 projects, ~90 M€ funding

8. TELECARE IN SCOTLAND Motivation • 46,500 hospital bed days saved by facilitating early hospital discharge • 225,000 care home bed days saved by delaying the requirement for people to enter care homes • 46,000 nights of sleep-over care and 905,000 home check visits saved by substitution of remote monitoring arrangements • Collectively, these savings are valued at around £43 million - an anticipated benefit to program funding cost ratio of 5:1.

9. Utility • Physiological Monitoring • ECG • Body Temp • Blood pressure • Respiratory Rate • Oxygen saturation • Surface EMG • Biomarkers (sweat) • Sympathetic/parasympathetic balance (e.g. mood)

10. Utility • Movement monitoring • Body position (e.g. falls) • Activity monitoring • Energy expenditure • Geolocation • Track activities • Localize people in need of urgent clinical care • Fuse with sensors embedded in the environment • Merging with survey data gathering in the field • Merging sensor and survey data

11. Related clinical conditions • Cardiac arrhythmias- 15 million • Sleep Apnea- Millions • Sudden Infant Death Syndrome 2,000/year • Nursing home • Falls 10%/year

12. Wearable Sensor Categories • Ambulatory Systems • First generation systems based on traditional sensor technology and data loggers (similar to Holter systems) with limited capability. • Cloth-Based Systems • Second generation systems based on sensors integrated in garments and relying on either wireless technology or e-textile solutions for data gathering.

13. First Generation (Ambulatory) Systems • NASA Lifeguard (2004)

14. Second Generation (Wearable) Systems • Systems based on wireless technology or e-textile solutions to gather and relay data to a remote site.

15. Second Generation (Wearable) Systems

16. Sensor Technology • Electrical resistance • Piezoelectric • Hall Sensors • Foam based • Wires wrapped around thread • Traditional Electrodes • Wireless controls

17. Examples • Zurich • Pisa • Madrid • Twente

18. Univ of Zurich (Balgrist Hospital) Prof. GregoireCourtine

19. Instrumented Glove • To date, the gloves developed, as far as now, present drawbacks • - sensor saturation • - sensor signal drift • - not being able to record all finger joints • To overcome these drawbacks, a new sensorized glove has been developed: the NeuroAssess Glove NeuroAssess Glove

20. Instrumented Glove • Specifications: • 6 resistive bend sensors • 0.5° resolution • 0.9° repeatability error • ± 3° accuracy • 100 Hz sampling rate

21. Smartex and University of Pisa Prof. DeRossi and Dr. Paradiso

22. Overview • Smartex (spin-off of University of Pisa) - Goal is to use textiles as a platform for unobtrusive monitoring • Devised a novel way of “printing” piezoelectric sensors onto elastic cloth at very low cost • 10 years old-company with 10 staff • Funding Milan textile industry, DARPA, NIH • Functional focus-manipulation, posture, balance, transfers and locomotion

23. Smartex Capabilities

24. Smartex products • Shirt (commercialized) with ECG and respiratory rate sensors. • Jumpsuit/pants with position sensors.

25. Products • Bed sheet (ECG, Resp Rate, Movement) • Elbow Sleeve (EMG, FES in development) • Glove (conductive elastomers, microbubbles for force measurement in development)

26. Tremor Project Prof. Jose Pons

27. TREMOR Project • Consortium of 8 European partners • Prof. José L. Pons (Project Coordinator), Consejo Superior de InvestigacionesCientíficas, Madrid, Spain along with 8 other European institutions http://www.iai.csic.es/tremor/index.htm • “An ambulatory BCI-driven tremor suppression system based on functional electrical stimulation” • “Tremor is most common movement disorder” • Managed with drugs, surgery (thalamotomy), and deep brain stimulation • Treatments are ineffective in 25% of patients

28. TREMOR PROJECT • Uses EEG and EMG along with IMUs to detect voluntary motion and tremor, using a sensor fusion approach • Use FES to either • Cancel tremor with out-of-phase stimulation • Stiffen the limb by co-contraction, to reduce tremor amplitude • Project at an early stage • Interesting use of FES making use of wearable sensors

29. University of Twente - MIRA Prof. Peter Veltink

30. Wearable Motion Analysis Laboratory

31. Human Movement Sensing • Inertial & magnetic sensors • 10+ years of research • Now commercially available (Xsens) • Utilized in peer-reviewed publications • Enables community, institution, and home based evaluations

32. Monitoring Dynamic Interactions • Foot – Ground interaction • Instrumented shoe • Two 6 DOF sensors • 2 inertial sensors • Hand – object • In development

33. Instrumented Shoe • Ground Reaction Forces • Center of Mass Leidtke et. al., 2007 Schepers et al, 2009

34. XSENS 3D Motion tracking Dr. Per Slycke

35. Company Overview • Founded 10 years ago - University of Twente spin-off. • Focus is 3D motion tracking. • 65 employees with 50% in research & development. • Focus is on 3 industries: 1) Industrial applications (unmanned vehicles), 2) Entertainment/training & simulation (movie special effects and video games), and 3) Movement science (how they started).

36. First Generation Sensor Technology • Real-time motion capture system. • Wired suit with power packs required. • Usable indoors or outdoors (difficult for video motion capture) with no marker occlusion issues. • Integration drift an issue for position estimates. First Generation Sensor

37. Second Generation Sensor Technology • Real-time motion capture. • No wires or power packs required. • Increased accuracy. • Usable indoors or outdoors with no occlusion issues. • Integration drift resolved through UWB RF technology. UWB RF Receiver Second Generation Sensor Recharge Station

38. Wearable Technology Gaps • Technology is not yet reliable for enough safety applications • EKG applications will need to be as good as standard electrodes to get traction • Kinematic technology not yet accurate enough for precise research applications (gait lab) • Xsens (1/10th level of accuracy)

39. Wearable Technology Gaps • System integration not yet adequate for commercialization and clinical application • Technical and data security issues • Wellness vs. medical applications • Unclear if end users are adequately involved in the design process

40. Conclusions • Wearable sensors hold great promise to: • Improve diagnostics • Monitor treatment • Enhance research outcomes • Increase independence and participation • Reduce healthcare costs • However, technology is only in its “second generation” • Will need to improve accuracy, reliability and system integration for true translation to occur