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
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
Motivation Community Based research Take the gait lab out of the hospital Measure research phenotyping Medication titration N of 1 trials
EUROPEAN COMMISSION Peter Wintlev-Jensen and Andreas Lymberis
Percentage of GDP (EU27) Source: EC '2009 Ageing Report: economic and budgetary projections for the EU-27 Member States (2008-2060)' 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. TELECARE IN SCOTLAND Motivation
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
Related clinical conditions Cardiac arrhythmias - 15 million Sleep Apnea- Millions Sudden Infant Death Syndrome 2,000/year Nursing home Falls 10%/year
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.
First Generation (Ambulatory) Systems NASA Lifeguard (2004)
Second Generation (Wearable) Systems Systems based on wireless technology or e-textile solutions to gather and relay data to a remote site.
UNIV OF ZURICH (BALGRIST HOSPITAL) Prof. Gregoire Courtine
Instrumented Glove To date, the gloves developed, as far as now, present drawbacksTo 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 GloveTo overcome these drawbacks, a new sensorized glove has been developed: the NeuroAssess Glove NeuroAssess Glove
SMARTEX AND UNIVERSITY OF PISA Prof. DeRossi and Dr. Paradiso
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
TREMOR Project Consortium of 8 European partners Prof. José L. Pons (Project Coordinator), Consejo Superior de Investigaciones Científicas, Madrid, Spain along with 8 other European institutions http://www.iai.csic.es/tremor/index.htmhttp://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
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
UNIVERSITY OF TWENTE - MIRA Prof. Peter Veltink
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
Monitoring Dynamic Interactions Foot – Ground interaction Instrumented shoe Two 6 DOF sensors 2 inertial sensors Hand – object In development
Instrumented Shoe Ground Reaction Forces Center of Mass Leidtke et. al., 2007 Schepers et al, 2009
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).
First Generation Sensor Technology First Generation Sensor 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.
Second Generation Sensor Technology Second Generation Sensor 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. Recharge Station UWB RF Receiver
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 (1/10 th level of accuracy)
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
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