MR compatible strain gauge based force transducer.

In order to evaluate brain activation during motor tasks accurately one must also measure output parameters such as muscle force or muscle activity. Especially in clinical situations where the force output can be compromised by changes at different levels of the motor system, it is essential to standardize the task or force level. We have therefore developed a magnetic resonance compatible force transducer that is capable of recording index finger abduction force and to display the produced force in real-time. This transducer is based on strain-gauges techniques and designed to measure both small and large forces accurately (range 0.7-60N) as well as fast force fluctuations. Experiments showed that the MR environment did not affect the force measurements or vice versa. Although, this transducer is developed for measuring index finger forces, detailed schematic diagrams are provided such that the transducer can easily be adapted for measuring forces of other muscle groups.