Considering that the noises resulting from low modulation frequency are serious and cannot be totally eliminated by the classic filters,a novel infrared(IR) gas concentration detection system based on the least square...Considering that the noises resulting from low modulation frequency are serious and cannot be totally eliminated by the classic filters,a novel infrared(IR) gas concentration detection system based on the least square fast transverse filtering(LS-FTF) self-adaptive modern filter structure is proposed.The principle,procedure and simulation on the LS-FTF algorithm are described.The system schematic diagram and key techniques are discussed.The procedures for the ARM7 processor,including LS-FTF and main program,are demonstrated.Comparisons between the experimental results of the detection system using the LS-FTF algorithm and those of the system without using this algorithm are performed.By using the LS-FTF algorithm,the maximum detection error is decreased from 14.3 to 5.4,and also the detection stability increases as the variation range of the relative error becomes much smaller.The proposed LS-FTF self-adaptive denoising method can be of practical value for mid-IR gas detection,especially for weak signal detection.展开更多
Based on wide-band infrared(IR) light source and dual-channel pyroelectric detector with detection channel of 4.66 μm and reference channel of 3.95 μm,a differential mid-infrared(MIR) carbon monoxide(CO) detector is...Based on wide-band infrared(IR) light source and dual-channel pyroelectric detector with detection channel of 4.66 μm and reference channel of 3.95 μm,a differential mid-infrared(MIR) carbon monoxide(CO) detector is designed and implemented.In order to reduce the detection limit and improve the detection sensitivity,an open spherical mirror chamber is designed and fabricated according to the divergence angle of the light source.The CO detection system is established using the welded and debugged detection circuits,a series of CO gases with different concentrations are prepared,and gas concentration calibration experiment is carried out.Experimental results indicate that after the amplifying circuit,the signal-to-noise ratios(SNRs) of the two channels are 17.58 dB and 18.46 dB,respectively,and the detection error of this system is less than 9% in 0%-4% measuring range.The detection sensitivity in the low concentration range is approximately 0.05%.6 h measurement on the 0 ppm sample gas shows that the fluctuation range is about ±0.02%,and the measurement standard deviation is about 0.89%.展开更多
A low power wavelet denoising chip for photoplethysmography （PPG） detection and portable heart rate monitoring is presented. To eliminate noise and improve detection accuracy, Harr wavelet （HWT） is chosen as the p...A low power wavelet denoising chip for photoplethysmography （PPG） detection and portable heart rate monitoring is presented. To eliminate noise and improve detection accuracy, Harr wavelet （HWT） is chosen as the processing tool. An optimized finite impulse response structure is proposed to lower the computational complexity of proposed algorithm, which is benefit for reducing the power consumption of proposed chip. The modulus max- ima pair location module is design to accurately locate the PPG peaks. A clock control unit is designed to further reduce the power consumption of the proposed chip. Fabricated with the 0.18μm N-well CMOS 1P6M technol- ogy, the power consumption of proposed chip is only 8.12μW in 1 V voltage supply. Validated with PPG signals in multiparameter intelligent monitoring in intensive care databases and signals acquired by the wrist photoelectric volume detection front end, the proposed chip can accurately detect PPG signals. The average sensitivity and positive prediction are 99.91% and 100%, respectively.展开更多
A design for a CMOS frontend integrated circuit （chip） for neural signal acquisition working at wide voltage supply range is presented in this paper. The chip consists of a preamplifier, a serial instrumental amplif...A design for a CMOS frontend integrated circuit （chip） for neural signal acquisition working at wide voltage supply range is presented in this paper. The chip consists of a preamplifier, a serial instrumental amplifier （IA） and a cyclic analog-to-digital converter （CADC）. The capacitive-coupled and capacitive-feedback topology combined with MOS-bipolar pseudo-resistor element is adopted in the preamplifier to create a -3 dB upper cut-off frequency less than 1 Hz without using a ponderous discrete device. A dual-amplifier instrumental amplifier is used to provide a low output impedance interface for ADC as well as to boost the gain. The preamplifier and the serial instrumental amplifier together provide a midband gain of 45.8 dB and have an input-referred noise of 6.7 μVrms integrated from 1 Hz to 5 kHz. The ADC digitizes the amplified signal at 12-bits precision with a highest sampling rate of 130 kS/s. The measured effective number of bits （ENOB） of the ADC is 8.7 bits. The entire circuit draws 165 to 216 μA current from the supply voltage varied from 1.34 to 3.3 V. The prototype chip is fabricated in the 0.18-μm CMOS process and occupies an area of 1.23 mm2 （including pads）. In-vitro recording was successfully carried out by the proposed frontend chip.展开更多
基金supported by the National "863" Project of China (Nos. 2007AA06Z112,2007AA03Z446 and 2009AA03Z442)the National Natural Science Foundation of China (No.61077074)the Science and Technology Department of Jilin Province of China (Nos. 20070709 and 20090422)
文摘Considering that the noises resulting from low modulation frequency are serious and cannot be totally eliminated by the classic filters,a novel infrared(IR) gas concentration detection system based on the least square fast transverse filtering(LS-FTF) self-adaptive modern filter structure is proposed.The principle,procedure and simulation on the LS-FTF algorithm are described.The system schematic diagram and key techniques are discussed.The procedures for the ARM7 processor,including LS-FTF and main program,are demonstrated.Comparisons between the experimental results of the detection system using the LS-FTF algorithm and those of the system without using this algorithm are performed.By using the LS-FTF algorithm,the maximum detection error is decreased from 14.3 to 5.4,and also the detection stability increases as the variation range of the relative error becomes much smaller.The proposed LS-FTF self-adaptive denoising method can be of practical value for mid-IR gas detection,especially for weak signal detection.
基金supported by the National Natural Science Foundation of China(No.61077074)the National Key Technology R&D Program(No.2013BAK06B04)+1 种基金the Science and Technology Department of Jilin Province of China(No.20120707)the Science and Technology Development of Changchun City of China(No.11GH01)
文摘Based on wide-band infrared(IR) light source and dual-channel pyroelectric detector with detection channel of 4.66 μm and reference channel of 3.95 μm,a differential mid-infrared(MIR) carbon monoxide(CO) detector is designed and implemented.In order to reduce the detection limit and improve the detection sensitivity,an open spherical mirror chamber is designed and fabricated according to the divergence angle of the light source.The CO detection system is established using the welded and debugged detection circuits,a series of CO gases with different concentrations are prepared,and gas concentration calibration experiment is carried out.Experimental results indicate that after the amplifying circuit,the signal-to-noise ratios(SNRs) of the two channels are 17.58 dB and 18.46 dB,respectively,and the detection error of this system is less than 9% in 0%-4% measuring range.The detection sensitivity in the low concentration range is approximately 0.05%.6 h measurement on the 0 ppm sample gas shows that the fluctuation range is about ±0.02%,and the measurement standard deviation is about 0.89%.
文摘A low power wavelet denoising chip for photoplethysmography （PPG） detection and portable heart rate monitoring is presented. To eliminate noise and improve detection accuracy, Harr wavelet （HWT） is chosen as the processing tool. An optimized finite impulse response structure is proposed to lower the computational complexity of proposed algorithm, which is benefit for reducing the power consumption of proposed chip. The modulus max- ima pair location module is design to accurately locate the PPG peaks. A clock control unit is designed to further reduce the power consumption of the proposed chip. Fabricated with the 0.18μm N-well CMOS 1P6M technol- ogy, the power consumption of proposed chip is only 8.12μW in 1 V voltage supply. Validated with PPG signals in multiparameter intelligent monitoring in intensive care databases and signals acquired by the wrist photoelectric volume detection front end, the proposed chip can accurately detect PPG signals. The average sensitivity and positive prediction are 99.91% and 100%, respectively.
基金Project supported by the National Natural Science Foundation of China(Nos.61474107,61372060,61335010,61275200,61178051)the Key Program of the Chinese Academy of Sciences(No.KJZD-EW-L11-01)
文摘A design for a CMOS frontend integrated circuit （chip） for neural signal acquisition working at wide voltage supply range is presented in this paper. The chip consists of a preamplifier, a serial instrumental amplifier （IA） and a cyclic analog-to-digital converter （CADC）. The capacitive-coupled and capacitive-feedback topology combined with MOS-bipolar pseudo-resistor element is adopted in the preamplifier to create a -3 dB upper cut-off frequency less than 1 Hz without using a ponderous discrete device. A dual-amplifier instrumental amplifier is used to provide a low output impedance interface for ADC as well as to boost the gain. The preamplifier and the serial instrumental amplifier together provide a midband gain of 45.8 dB and have an input-referred noise of 6.7 μVrms integrated from 1 Hz to 5 kHz. The ADC digitizes the amplified signal at 12-bits precision with a highest sampling rate of 130 kS/s. The measured effective number of bits （ENOB） of the ADC is 8.7 bits. The entire circuit draws 165 to 216 μA current from the supply voltage varied from 1.34 to 3.3 V. The prototype chip is fabricated in the 0.18-μm CMOS process and occupies an area of 1.23 mm2 （including pads）. In-vitro recording was successfully carried out by the proposed frontend chip.
