Browsing by Author "Yang, Tzu-Sen"

Now showing 1 - 4 of 4

A Contact Lens Sensor System with a Micro-Capacitor for Wireless Intraocular Pressure Monitoring
(2013)
Huang, Yu-Chieh
;
Yeh, Guan-Ting
;
Yang, Tzu-Sen
;
Chiou, Jin-Chern
;
電控工程研究所
This paper proposes a novel micro-capacitor sensor for intraocular pressure (IOP) measurement on soft contact lens. The sensor was designed and fabricated by using MEMS fabrication technologies. The contact lens is for wearing on a cornea such that a curvature of the contact lens corresponds substantially to that of the cornea, and is preferably made of Hydroxyethylmethacrylate (HEMA) by cast-molding method of soft contact lens for high oxygen permeability and comfortable long-duration wearing. The prototype without wireless antenna has been implemented with a sensitivity of 0.43 pF/mmHg in measurement of human eye like balloon pressure test between 100 mmHg and 180 mmHg. The results show its high stability and reproducibility in a series of repeatable pressure variation. In future work the micro-capacitor will be tested on enucleated porcine eyes with better and integrated with a radio frequency integrated circuit and antenna on soft contact lens so that IOP value could be transferred to voltage value via capacitor to voltage converter and transmits IOP sensing signal by wireless telemetry system.
A Novel Pseudo Resistor Structure for Biomedical Front-end Amplifiers
(2015)
Huang, Yu-Chieh
;
Yang, Tzu-Sen
;
Hsu, Shun-Hsi
;
Chen, Xin-Zhuang
;
Chiou, Jin-Chern
This study proposes a novel pseudo resistor structure with a tunable DC bias voltage for biomedical front-end amplifiers (FEAs). In the proposed FEA, the high-pass filter composed of differential difference amplifier and a pseudo resistor is implemented. The FEA is manufactured by using a standard TSMC 0.35 mu m CMOS process. In this study, three types FEAs included three different pseudo resistor are simulated, fabricated and measured for comparison and electrocorticography (ECoG) measurement, and all the results show the proposed pseudo resistor is superior to other two types in bandwidth. In chip implementation, the lower and upper cutoff frequencies of the high-pass filter with the proposed pseudo resistor are 0.15 Hz and 4.98 KHz, respectively. It also demonstrates lower total harmonic distortion performance of -58 dB at 1 kHz and higher stability with wide supply range (1.8 V and 3.3 V) and control voltage range (0.9 V and 1.65 V) than others. Moreover, the FEA with the proposed pseudo successfully recorded spike-and-wave discharges of ECoG signal in in vivo experiment on rat with pentylenetetrazol-induced seizures.
An RFID-based On-lens Sensor System for Long-Term IOP Monitoring
(2015)
Hsu, Shun-Hsi
;
Chiou, Jin-Chern
;
Liao, Yu-Te
;
Yang, Tzu-Sen
;
Kuei, Cheng-Kai
In this paper, an RFID-based on-lens sensor system is proposed for noninvasive long-term intraocular pressure monitoring. The proposed sensor IC, fabricated in a 0.18um CMOS process, consists of capacitive sensor readout circuitry, RFID communication circuits, and digital processing units. The sensor IC is integrated with electroplating capacitive sensors and a receiving antenna on the contact lens. The sensor IC can be wirelessly powered, communicate with RFID compatible equipment, and perform IOP measurement using on-lens capacitive sensor continuously from a 2cm distance while the incident power from an RFID reader is 20 dBm. The proposed system is compatible to Gen2 RFID protocol, extending the flexibility and reducing the self-developed firmware efforts.
Novel Application of Ring-oscillator-based Sensor for 3D IC Temperature and IR Drop Monitoring
(2017-01-01)
Chiou, Jin-Chern
;
Yang, Tzu-Sen
;
Tsai, Shang-Wei
;
電機工程學系
;
Department of Electrical and Computer Engineering
This paper proposes a novel method to clearly differentiate the distinct problems of temperature and IR drop inside a chip. This method involves the placement of two same ring-oscillator-based sensors in specific areas. Simulation results show that as temperature increases, the digital counter output of the ring-oscillator-based sensor decreases. Alternatively, a decrease in the power supply decreases the digital output of the ring-oscillator-based sensor. Results also show that when the digital circuit speed was slow, the difference between the digital count outputs of the two sensors became very small; this difference was very large when the speed was high. Thus, the difference between the digital count outputs of the two sensors represents the internal power status of the chip.