[Six channels telemetry system for recording masticatory forces of complete denture wearers]

A six channels telemetry system for recording masticatory force of complete denture wearers has been developed. This system is consisted of three blocks, the transmission block, the receiver block and the data storage and correction block. The transmission block is embedded in a lower complete denture. System has six load sensors and a standard resistor to correct sensor data. Data from six load sensors and standard resistor as well as standard zero are multiplexed using a division multiplex communication method. The sampling frequency is 666 Hz. And the signal is transmitted by FM modulation. The carrier wave frequency is 64 MHz. Receive data are decoded using start-stop system. The wave form noise is reduced using a signal averaging technique at an integrator. The data are input into the computer with an A/D converter. In this system, the sensor data is corrected at the computer with the standard resistor data. This method could reduce the influence of battery power changes and thermal drift significantly. For the load of 10 kg or less, the total linearity of the system remained at +/- 4% of the calibrated value. The noise level is 300 g.