Ultrasound Imaging for Understanding Muscle Dynamics
Muscles are biological actuators that can act as motors, clutches, and dampers. Much like how mechanical systems have operating characteristics, the magnitude and economy of force generation in skeletal muscles are dependent on length, velocity, and the amount of activation. More traditional metrics, such as electromyography and inverse dynamics, are incapable of directly measuring many of these operating characteristics. We are using ultrasound imaging to directly measure how muscles respond to robotic assistance during walking. The approach to understanding human/machine interaction combines the research areas of computer vision, engineering, biomechanics, and muscle physiology. Drawing from expertise in the lab, we are developing improved ultrasound processing techniques for tracking and understanding muscle dynamics. Through understanding how muscles respond to exosuit assistance, we can then develop improved controls and enhance the response of both healthy and clinical users.
Researchers: Letizia Gionfrida, Alperen Degirmenci, Richard Nuckols
Soft Orthotics
Stroke is the leading cause of long-term disability in the United States, affecting over 750,000 people annually. In order to regain motor function of the upper body, patients are usually treated by regular sessions with a dedicated physical therapist. However, the use of therapists is expensive, in high demand, and requires the patient to travel to a rehabilitation clinic.
We propose an inexpensive wearable upper body orthotics system that can be used at home to empower both the patients and physical therapists. The system is composed of a thin, compliant, lightweight soft orthotic device with an integrated cable actuation system that is worn over the upper body, an embedded limb position sensing system, and an actuator package.
Researchers: Ignacio Galiana, Frank Hammond III, Samuel Kesner, Leif Jentoft, and Marko Popovic
Hand Therapy Exercise Device
Patients who undergo hand surgeries requiring tendon repair often face difficulties regaining normal hand function. Among the potential problems encountered is decreased mobility, brought on by tendon adhesions, swelling, and tendon/ligament contractures. These are common undesirable effects of postoperative immobilization that reduce hand functionality and occasionally require secondary surgeries.
Tendon gliding exercises that break up unwanted scar tissue are standard practice during postoperative hand rehabilitation and have improved patient prognosis. A typical set of exercises is shown in Fig. 1, used by therapists to move the patient’s finger through six distinct positions, each targeting a different set of tendons.
This project seeks to develop a cable-driven hand exoskeleton that is capable of mimicking tendon gliding biomechanics and automating all six therapy exercises (Fig. 2). The exoskeleton also adopts a simplified actuation mechanism that reduces the number of active components by using passive return elements.
Researchers: Raye Yeow