Project Title: Wrist Strength Testing Device
Presenter Names: Whitney Karpen, Mike Woizeschke, Garrett Hansen
Department: Mechanical Engineering
Faculty Advisor: Mike Twedt
Sponsor: Mayo Clinic: Motion Analysis Lab

              The objective of this project is to design, calibrate, and build a fully functional wrist strength testing device that does not require the patient to have the ability to grasp the handle. The wrist strength testing device’s original intention was to be able to determine the forces a patient could create with his wrist. The current design is a pistol style grip attached to an assembly with three torque cells; one on each of the three axes. Presently, the subject grips the handle and pronates, supinates, flexes, and extends his hand. The subject also deviates his arm in the radial and ulnar directions. This produces a moment that is read by the torque cells. This information is then sent to a computer interface that is read by the technician. 
              The problem encountered with the current design is that not all test subjects are able to grasp the pistol grip effectively. Some subjects who are being tested have suffered an injury to their wrist or have recently undergone surgery and they do not possess the strength to grasp the handle. The new design will restrain the subject’s hand in a manner that will comfortably stabilize it. The problem encountered with the new design is the compromise between comfort and stability. All of the newly designed parts and mechanisms must also fit in the space that the current model fills.
              The new design was not intended to replace the current system. If the subject has grasping capabilities, the current system will be used. This presents a design issue. The current and new designs need to be interchangeable. A quick change-out mechanism is required to provide efficient switching of parts from the current model to the newly designed model. After the design is created, the final portion of the project is calibration. The new design will be calibrated using an improved computer interface. The calibration technique will ideally be simple enough to complete on a regular basis.