Project Summary
A great deal of development has occurred in the past few decades to allow electronics for body monitoring to be worn comfortably on the body. New methods for developing smaller microprocessors, lower power devices and new techniques for creating flexible fibers for electrical wiring in the textile industry have created opportunities for new applications in the market for wearables. However, although this technology is increasingly available, the next challenge is for developers and engineers to translate this technology into a meaningful product which regards the human body as a context. During my fellowship year I worked with Textile Engineers to test a prototype for acquiring surface electromyographic signals. The band was created using an intarsia knitting technique to connect the electrical channels to allow for ease of manufacturing and high level wearability and integration.
My Role
During the course of the fellowship year I worked with signal processing techniques to analyze surface electromyographic signals picked up from the muscle activation of the lower arm for arm rotation (supination and pronation) , wrist flexion and extension and grasping movements using dry and wet textile electrodes. I was responsible for setting up the experimental protocols and testing for the textile electrode performance in offline prediction algorithms as well as real time prediction.
About the Garment:
The textile electrodes (textrodes) were integrated into a sensorized arm band using intarsia, a knitting technique in which there is only one active yarn on any given stitch, and yarn is not carried across the back of the work; when a yarn changes on a given row, the old yarn is left hanging which allows for the creation of insulated electrical channels and electrode surfaces. The advantages of textile electrodes integrated into a garment used for the acquisition of muscle signals (sEMG) is that a properly designed and fitted garment would allow the user to don on and off the garment without having to understand optimal positioning of the electrodes and would allow for a quicker set up and clean up period when compared to the traditional industry standard adhesive silver chloride electrodes and the fully integrated solution allows for the highest level of wearability.
Signal Processing Tools
Matlab
Biopatrec (first open source platform for the development and benchmarking of advanced prosthetic control strategies based on pattern recognition of myoelectric signals, i.e., BioPatRec allows prediction of motor intent through the decoding of muscular activity)
Testing Results
Textile electrodes when compared to the industry standard for sEMG acquisition was found to be roughly equivalent in signal quality for applications predicting motor volition. Further research ongoing in improving the quality of the signal acquisition interface includes developing methods for reduction in motion artifacts both through signal filtering techniques and lead off detection as well as manufacturing the garment so that it increases the local pressure at the skin electrode interface therefore decreasing the impedance, motion artifacts and ground noise in the muscle signals.
Reflection:
During my time as a Whitaker International Research fellow I was given the opportunity to work with a wide range of talented researchers and professionals from around the world and the chance to pursue my interest in Human Computer Interaction and developing ubiquitous wearable interfaces for improving human health. Over the course of the year, I was introduced to the science of Textile Engineering as well as developed a deeper understanding of biometric signal processing. I realized that my strength as a researcher in this field was to act as a bridge between disciplines and my background as a Biomedical engineer with a strong interest in design, textiles and user experience allowed me to delve deep into this emerging field. The mentors and researchers I met during this project guided me toward future opportunities to grow as a researcher in Sweden which led me to pursue my Masters Degree in Interaction Design Engineering at Chalmers University of Technology.
Conference Proceedings
1. Brown, S., Ortiz-Catalan, M., Petersson, J., Rödby, K., and Seoane, F., Intarsia-Sensorized Band and Textrodes for the Real-Time Acquisition of Myoelectric Signals, 38th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC), Orlando, Aug. 16-20, 2016.
2. Brown, S., Ortiz-Catalan, M., Petersson, J., Rödby, K., and Seoane, F., Intarsia-Sensorized Band and Textrodes for the Acquisition of Myoelectric Signals, 2nd International Conference on Smart Portable, Wearable, Implantable and Disability-oriented Devices and Systems (SPWID), Valencia, May 22-26, 2016.
Read Full Text (Research Gate)
Read more about the smart textile design lab and their efforts to create ubiquitous technologies embedded in textiles in the link below.
