WARF: P06028US

Electromechanical Force-Magnitude, Force-Angle Sensor


Kreg Gruben, Matthew Schmidt

The Wisconsin Alumni Research Foundation (WARF) is seeking commercial partners interested in developing an improved, less expensive force sensor.
OVERVIEWUW-Madison researchers previously described a piece of exercise equipment for rehabilitation of stroke patients and sport-specific training of athletes that allows users to measure and train the magnitude and direction of the force generated with the leg (see WARF reference number P05358US).
THE INVENTIONUW-Madison researchers have now developed an improved, less expensive force sensor for that device. The new sensor measures force direction from the orientation of a mechanical linkage between a pedal and the base. The linkage moves like a weathervane—always aligning itself with the force. This increases accuracy and simplifies measurement of force direction and magnitude.

The orientation of the linkage is measured to obtain force direction, while strain gages are only used along a single axis to determine force magnitude. This design eliminates several problems inherent in existing multi-axis strain gage systems, such as the need for multiple strain gages along multiple axes, the complex vector mathematics required to use them, the difficulties of calibrating the strain gages and the inaccuracies caused by cross-talk between sensors.
  • Rehabilitation of stroke patients
  • Training for high performance athletes, particularly bicyclists
  • Compact
  • Less expensive than current devices
  • Less complex than currently available devices
  • Accurately measures direction and magnitude of force
  • Does not exhibit inaccuracies due to sensor cross-talk
  • Eliminates need for multiple force sensors, which must be calibrated with each other
For More Information About the Inventors
Contact Information
For current licensing status, please contact Jeanine Burmania at or 608-960-9846.
The WARF Advantage

Since its founding in 1925 as the patenting and licensing organization for the University of Wisconsin-Madison, WARF has been working with business and industry to transform university research into products that benefit society. WARF intellectual property managers and licensing staff members are leaders in the field of university-based technology transfer. They are familiar with the intricacies of patenting, have worked with researchers in relevant disciplines, understand industries and markets, and have negotiated innovative licensing strategies to meet the individual needs of business clients.