Abstract

System originally developed for Track-HD project (R Reilmann) due to externally opened force measuring chain, can be vulnerable to upper body and head movements, which may interfere with measured tongue force. The sensor housing is attached to the external frame against which subject suppose to rest during the measurement. The tongue pushing muscles (four extrinsic glossus muscles) are anchored in the bottom part of oral cavity. The housing of the force transducer should be attached to the same biomechanical structure which serves muscles anchoring. The most steady fixation surface provides the bite that allow comfortable holding of transducer between the teeth. Transducer housing has cylindrical form of 13 mm diameter with the butterfly plate at its top, preventing its slippage out of the mouth (a modified syringe). The opposite slotted tip of the syringe, serves as the bayonet connection, allowing to attach the force sensor in precisely centered position. Pushing force of the tongue, which always stays inside the mouth, is transmitted to the force sensor by the syringe plunger with removed sealed tip. To prevent the damage of the force sensor by applying the force above 45N, there is a short spring giving the transducer additional elasticity which passes to the excessive force to the sensor enclosure. Authors explored the possibility of characterising the tongue force instability with the single number parameter like the surface under the rectified AC force signal, as well as the number of crossings the line of required force level. Force transducer may be connected to the universal data acquisition system originally developed for measuring saccadic eye movements.