Research Interests
Dr. Fite’s research interests lie in the area of dynamic systems and control, with specific focus in the design and control of electromechanical and fluid power systems. A major thrust of this work is in the development of self-powered human-scale robotic systems.
Applications of particular interest include upper and lower-extremity powered prosthetic limbs. The major goal of this work is the restoration of human-level functionality and performance to the amputee. One aspect involves the design of prosthetic limbs capable of force and power outputs comparable to those of normal human limbs. Such designs require the integration of the power supply, actuation system, and control electronics all within the volumetric envelope of a normal human limb. Another component of the prosthesis development entails the development of the communication interface with the amputee. Current work is investigating the use of EMG-based control approaches where measured muscle activity in the residual limb is utilized as input commands to the prosthetic limb. The objective is an artificial limb which behaves as a natural extension of the amputee’s residual limb.
Other broad areas of interest include the development of power and actuation for portable power systems. The goal of this research is to improve upon the limitations inherent in battery-powered DC-motor actuated systems by investigating the use of alternative energy sources (e.g., compressed gas sources, liquid and solid propellants) and actuation systems (e.g., pneumatic and hydraulic actuators) that can be used to deliver controllable mechanical work outputs. Relevant applications include self-powered robots, portable power and rescue tools, and lawn care equipment.
Below are some of the topics that Dr. Fite’s lab is currently exploring.
Body-Powered Prosthetic Fingers for an Individual with Partial-Hand Amputation due to Traumatic Injury
Project Summary
The objective of this project was to develop a passive (non-powered) hand prosthesis to enhance grip and grasp function for an individual with partial-hand amputation. A team of undergraduate students worked collaboratively with our client end-user (a child in an elementary school local to Clarkson University) and his family in the design of prosthetic fingers for improved grip/grasp when playing sports such as hockey and lacrosse. The client end-user for this project was a 10 year-old boy who suffered a traumatic injury as an infant that resulted in the loss of his thumb and the distal segments of fingers four and five. As a result of the injury, almost all thumb function was lost, but the child retained the ability to flex the remaining segments of the ring and pinky fingers.
The design team developed a body-powered, linkage-based solution for flexing the prosthetic fingers. The socket interface for the prosthesis consists of a three-ring system, each of which is sized to fit the user’s intact middle finger and residual ring and pink fingers, respectively. A mechanical linkage connects the prosthetic fingers to the intact middle finger, enabling flexion of the prosthetic fingers using middle-finger movement. The prototype prosthetic finger system improves the user’s ability to perform cylindrical grips conducive to holding objects with rectangular or circular cross-sections, such as hockey and lacrosse sticks.
- A body-powered, linkage-based prosthetic finger system
- A three-ring socket interface sized to the user’s intact middle finger and residual fingers
- Prosthetic finger motion mechanically linked to flexion/extension of the intact middle finger
- Provides improved cylindrical grip function for holding objects with rectangular and circular cross-sections
An Energy-Storage-and-Release Device to Assist Nordic Ski Poling for Individuals with Muscular Degeneration in the Upper Arm
and elbow interfaces.
Project Summary
The object of this effort was the development of an energy-storage-and-return (ESAR) system to assist with arm raising functions when cross-country skiing. The specific client end-user for this project is an avid cross-country and back-country skier who suffers from monomelic amyotrophy of the right arm, a rare motor-neuron disease that results in significant single-limb muscle weakness. The impact of the disease on skiing is such that, while the user has significant arm strength to push on the pole for forward propulsion, weakness when swinging the arm forward and bending the elbow on the return stroke is highly impaired.
An undergraduate design team developed an arm assist system comprising shoulder/torso harness, wrist and elbow interfaces, and rubber springs spanning from the wrist and elbow to the rear of the harness. When the user extends their elbow and rotates their arm back, the springs are stretched to store energy that is returned to the user during the forward return stroke. The design prototype incorporates adjustable-length, quick-connect springs to facilitate a customized fit. Additionally, the level of assist at both the wrist and elbow can be modulated by choosing among four different spring stiffness values.
- User attachment via shoulder/torso harness and wrist and elbow braces
- Energy storage and return using rubber springs spanning from harness to the wrist and elbow
- Energy storage during the push stroke as the elbow extends and the rotates back
- Energy returned to the arm during the forward return stroke
- Size of the system is customizable to the individual user
- Level of assist at both the wrist and elbow is user-selectable