A Flexible Capacitive Tactile Sensor Array With CMOS Readout Circuits for Pulse Diagnosis

• Published in: IEEE sensors journal Vol. 15; no. 2; pp. 1170 - 1177
• Main Authors: Jen-Yu Peng, Lu, Michael S-C
• Format: Journal Article
• Language: English
• Published: IEEE 01.02.2015
• Subjects: Capacitance; Capacitive sensors; CMOS; Electrodes; Flexible capacitive tactile sensor; Pulse diagnosis; Sensitivity; Sensor arrays; flexible capacitive tactile sensor; CMOS; pulse diagnosis
• ISSN: 1530-437X; 1558-1748
• DOI: 10.1109/JSEN.2014.2360777

Pulse diagnosis is one of the major methods used in traditional Chinese medicine to evaluate a patient's health conditions. Determination of pulse patterns is, however, a matter that depends on technical skill and subjective experience of a doctor. Development of a pulse diagnosis apparatus can lead to modernization and advancement of the field by providing more objective and accurate evaluations. This paper aims at demonstrating real-time pulse measurement using the developed flexible capacitive tactile sensors. A 5\times 5 sensor array of 0.75 cm \times 1 cm in size was implemented using flexible printed circuit boards and integrated with CMOS switched-capacitor readout circuits. The measured average output sensitivity was 1.57 mV/mmHg and minimum detectable pressure and capacitance were at the sub-mmHg and sub-fF levels, respectively. The cross sensitivity was measured to be 7.8%. Real-time pulse measurement has been successfully demonstrated using the developed flexible sensor array.