A 2.3 mu W Wireless Intraocular Pressure/Temperature Monitor

作者：Shih Yi Chun^*; Shen Tueng; Otis Brian P

来源：IEEE Journal of Solid-State Circuits, 2011, 46(11): 2592-2601.

DOI：10.1109/JSSC.2011.2164134

• Bioelectronics
• biomedical
• capacitance sensing
• implantable electronics
• intraocular pressure
• low-power
• pressure sensing
• relaxation oscillator
• temperature sensing

We present the design of an ultra-low power, wireless pressure/temperature sensing device for continuous intraocular pressure monitoring. The device is wirelessly powered and demonstrates a power consumption of 2.3 mu W at 1.5 V during continuous monitoring. The chip converts both capacitance and temperature to frequency using a time-interleaved relaxation oscillator, which modulates RF backscatter to a reader for computation of measured samples. A significant reduction in power consumption results from the elimination of the digitization circuitry, time-multiplexed operation, and moving the signal processing burden to the external reader using analog IF-modulated backscatter. The chip exhibits measured capacitance and temperature standard deviations of 1.4 fF and 0.4 degrees C, respectively.