New applications of ultrasound-based muscle activity sensing for rehabilitation engineering

Traditionally, electromyography using surface electrodes has been the dominant method for sensing muscle activity. Major challenges with surface electromyography include the difficulty in resolving signals from overlying muscles and low signal to noise ratio. In recent years, ultrasound has been investigated as an alternative and complementary modality for sensing functional muscle activity that overcomes several limitations of surface electromyography. Ultrasound imaging can non-invasively resolve individual muscles, including deep and overlying muscles, and detect dynamic activity within different functional compartments in real-time. While the use of ultrasound in the biomechanics community has a long history, the continuing miniaturization of ultrasound instrumentation has opened up new opportunities for using ultrasound in rehabilitation engineering as a biosignal sensing modality for assistive devices. This talk will describe results from our current work on developing miniaturized low-power ultrasound instrumentation for wearable systems, including next generation prostheses and exoskeletons. I will also describe opportunities and limitations for applications of ultrasound in rehabilitation engineering.