ICsense

The datalogger IC has been developed in cooperation with the department of prosthetic dentistry of the K.U.Leuven in order to study bone remodeling processes around dental implants. The datalogger, part of a dental prosthesis, measures and processes the in vivo loads on the dental implants by means of strain gauges. A wireless transceiver is included in the datalogger for (re-)programming of the operation mode in situ and data retrieval. The datalogger is able to monitor autonomously and continuously over a 2-day period independent of the hospital environment using a miniaturized battery.
The single-chip 18-channel strain-gauge datalogger IC is integrated in a 0.7-µm CMOS technology. It combines a 10-µstrain-accuracy sensor interface with digital offset-compensation, a wireless 132kHz/66kHz transceiver and a 23.4-kgates digital unit with programmable data processing. The sensor interface includes a current reference, an 8-bit DAC, together with a digital interface to achieve multi-gauge nulling, an offset-compensated SC instrumentation amplifier, a SC S/H and a 9-bit successive approximation ADC. The datalogger's maximum power consumption, including an external 2-Mbit RAM, is 136 µW/channel at 3.1 V.