Assisting Human Grasping
Robots hold the potential to assist people through direct physical contact. Our work focuses on wearable robotic devices, like orthotics and prosthetics, and psychophysical studies in the context of physical human-robot interaction.
Current researchers (August 2024): Erin Chang, Drew McPherson, Wilson Torres, Jungpyo Lee, Ben Davis.
< Back to previous pageBody powered devices, such as bowden-cable driven prosthetic hands, offer the benefit of passive extended physiological proprioception. We are studying the role and characteristics of this kinesthetic feedback method in order to better augment passive systems and design more intuitive active systems.
Characterizing the force-motion tradeoff in body-powered transmission design
Kinesthetic feedback improves grasp performance in cable-driven prostheses
Effect of variable transmission on body-powered prosthetic grasping
A wearable testbed for studying variable transmission in body-powered prosthetic gripping
The back of the hand is rarely considered a feasible grasping surface, in part because the skin is fragile and flexible and it is not consciously used in normative grasping. We are exploring how we can enable grasping with the back of the hand with the addition of supernumerary palm and fingers, and how this technology may be useful especially for people who have impaired finger function.
Assistive supernumerary grasping with the back of the hand
In hand orthotics, operators are often asked to use their wrist pose to command finger pose. However, linking wrist and hand movements can create kinematic constraints on the body that make some grasping motions difficult to achieve. We are modeling the potential negative consequences of this user input command strategy in a number of devices, from the completely passive Wrist-Driven-Orthosis linkage designed for people with certain types of Spinal Cord Injury, to fully-active solutions like the Single-Sized Semi-Soft Assistive Mitten (SSAM). We are exploring how a hybrid solution, the Motor-Augmented Wrist Driven Orthosis (MWDO) can be used to reduce the challenges that arise from such a device while harnessing the benefits of intuitive body-power.
Modulating Wrist-Hand Kinematics in Motorized Assisted Grasping With C5-6 Spinal Cord Injury
Tenodesis Grasp Emulator: Kinematic Assessment of Wrist-Driven Orthotic Control
Robotically adjustable kinematics in a wrist- driven orthosis eases grasping across tasks
Motor-Augmented Wrist-Driven Orthosis: Flexible Grasp Assistance for People with Spinal Cord Injury
Hybrid Control Interface of a Semi-soft Assistive Glove for People with Spinal Cord Injuries
Ongoing work is looking at characterizing and describing various methods that people with cervical spinal cord injury use to perform dexterous tasks in their daily lives. Our first work in the area can be found here: A Grasp Taxonomy for People with C5-7 Spinal Cord Injury
Skin sensitivity changes can be a marker of underlying health concerns and changing symptoms. However, clinical measures of sensitivity of the fingertips are not often collected with much frequency. We found the first correlation between the monofilament test and a smartphone enabled vibration perception threshold, providing key evidence that smartphones could enable more regular and accessible fingertip diagnostics at home.
Tap and swipe smartphone gestures indicate hand tremor and finger joint range of motion
Skin Sensitivity Assessment Using Smartphone Haptic Feedback