Assessment of neuromuscular blockade during anesthesia is achieved using the Train of Four (TOF) monitoring technique. However, current devices are limited to conditions in which the hand can move freely during operation. The goal of this project was to design, prototype, and test a device which extends the TOF technique to conditions where movement is restricted. Interviews were conducted with stakeholders to better understand the need for this device and to get feedback on preliminary designs. The resulting device consists of a thumb-mounted balloon, which converts the force due to thumb twitches into pressure, which then acts as the physical analog to muscle response. This pressure is transduced and analyzed to produce a TOF count and TOF ratio. A prototype was constructed and tested on human subjects with different hand geometries.