Pub Date : 2010-11-01DOI: 10.1109/BIOCAS.2010.5709619
C. Posch, D. Matolin, R. Wohlgenannt, M. Hofstatter, P. Schon, M. Litzenberger, Daniel Bauer, H. Garn
This paper presents a high DR, high temporal resolution, frame-free image/video camera that encodes and processes visual information in asynchronous spikes. The event-driven optical sensor features 9.3-bit grayscale imaging at up to 143dB DR and <0.25% FPN with hardware-based lossless video compression and time-domain correlated double sampling. The main components of the camera — the asynchronous, time-based image sensor (ATIS) and a general purpose Address-Event processor (GAEP) with 20-Bit 10ns-resolution sensor data interface — have been specifically designed with the goal to implementing a biomimetic, asynchronous, frame-free approach to vision. The presented system optimally combines the advantages of time-based (PWM) imaging, bio-inspired temporal contrast dynamic vision and event-based (AER) information encoding and data communication, and achieves exceptional performance in terms of dynamic range, FPN, temporal resolution, gray-level resolution and data compression.
{"title":"Biomimetic frame-free HDR camera with event-driven PWM image/video sensor and full-custom address-event processor","authors":"C. Posch, D. Matolin, R. Wohlgenannt, M. Hofstatter, P. Schon, M. Litzenberger, Daniel Bauer, H. Garn","doi":"10.1109/BIOCAS.2010.5709619","DOIUrl":"https://doi.org/10.1109/BIOCAS.2010.5709619","url":null,"abstract":"This paper presents a high DR, high temporal resolution, frame-free image/video camera that encodes and processes visual information in asynchronous spikes. The event-driven optical sensor features 9.3-bit grayscale imaging at up to 143dB DR and <0.25% FPN with hardware-based lossless video compression and time-domain correlated double sampling. The main components of the camera — the asynchronous, time-based image sensor (ATIS) and a general purpose Address-Event processor (GAEP) with 20-Bit 10ns-resolution sensor data interface — have been specifically designed with the goal to implementing a biomimetic, asynchronous, frame-free approach to vision. The presented system optimally combines the advantages of time-based (PWM) imaging, bio-inspired temporal contrast dynamic vision and event-based (AER) information encoding and data communication, and achieves exceptional performance in terms of dynamic range, FPN, temporal resolution, gray-level resolution and data compression.","PeriodicalId":440499,"journal":{"name":"2010 Biomedical Circuits and Systems Conference (BioCAS)","volume":"117 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133491537","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-11-01DOI: 10.1109/BIOCAS.2010.5709584
A. Zbrzeski, P. Hasler, Florian Kolbl, Emilie Syed, N. Lewis, S. Renaud
Neural recording and processing systems are key instruments for investigating brain mechanisms, related to pathologies for example. For preliminary investigations on the mechanisms, we don't exactly know what the useful information is and how we should process it; thus we propose to use a reconfigurable device for the recording systems before full-custom ASIC fabrication. We use Large-Scale FPAA for interactive prototyping of the analog front-end functions involved in bio-potential recording. This paper presents a configurable measurement bench for in vivo brain LFP recording. We give electrical performances and detail the experimental methodology and measurements conducted on anesthetized and moving rats.
{"title":"A programmable bioamplifier on FPAA for in vivo neural recording","authors":"A. Zbrzeski, P. Hasler, Florian Kolbl, Emilie Syed, N. Lewis, S. Renaud","doi":"10.1109/BIOCAS.2010.5709584","DOIUrl":"https://doi.org/10.1109/BIOCAS.2010.5709584","url":null,"abstract":"Neural recording and processing systems are key instruments for investigating brain mechanisms, related to pathologies for example. For preliminary investigations on the mechanisms, we don't exactly know what the useful information is and how we should process it; thus we propose to use a reconfigurable device for the recording systems before full-custom ASIC fabrication. We use Large-Scale FPAA for interactive prototyping of the analog front-end functions involved in bio-potential recording. This paper presents a configurable measurement bench for in vivo brain LFP recording. We give electrical performances and detail the experimental methodology and measurements conducted on anesthetized and moving rats.","PeriodicalId":440499,"journal":{"name":"2010 Biomedical Circuits and Systems Conference (BioCAS)","volume":"79 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117221217","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-11-01DOI: 10.1109/BIOCAS.2010.5709577
Cheng-Kai Lu, T. Tang, F. Alan, A. Laude, B. Dhillon
Parapapillary atrophy (PPA) in the retina has been associated with eye diseases (e.g. glaucoma) and certain eye conditions (e.g. myopia). However, no computer-aided measuring tool thus far is available to quantify the extent of the PPA. In this paper, a novel approach to automatically segment and quantify the optic disc (OD) and PPA is proposed. The methodology exploits both the red and blue channels of the colour image to maximise information extraction of features (PPA) whilst keeping interference (blood vessels) to a minimum. A combination of several techniques, including scanning filter, thresholding, region growing as well as modified Chan-Vese (C-V) model with a shape constraint is used to segment and quantify the OD and PPA. Our proposed approach is evaluated against the reference boundary drawn by an ophthalmologist. Experimental results show that our method can repeatedly detect both the sizes of the OD and PPA region automatically, and achieved a mean accuracy level of 91.3% and 92.5% in defining the size of the OD and PPA, respectively. Moreover, the correlation coefficient of the ground truth and the results from proposed method is 0.98 for both the PPA and OD.
{"title":"Automatic parapapillary atrophy shape detection and quantification in colour fundus images","authors":"Cheng-Kai Lu, T. Tang, F. Alan, A. Laude, B. Dhillon","doi":"10.1109/BIOCAS.2010.5709577","DOIUrl":"https://doi.org/10.1109/BIOCAS.2010.5709577","url":null,"abstract":"Parapapillary atrophy (PPA) in the retina has been associated with eye diseases (e.g. glaucoma) and certain eye conditions (e.g. myopia). However, no computer-aided measuring tool thus far is available to quantify the extent of the PPA. In this paper, a novel approach to automatically segment and quantify the optic disc (OD) and PPA is proposed. The methodology exploits both the red and blue channels of the colour image to maximise information extraction of features (PPA) whilst keeping interference (blood vessels) to a minimum. A combination of several techniques, including scanning filter, thresholding, region growing as well as modified Chan-Vese (C-V) model with a shape constraint is used to segment and quantify the OD and PPA. Our proposed approach is evaluated against the reference boundary drawn by an ophthalmologist. Experimental results show that our method can repeatedly detect both the sizes of the OD and PPA region automatically, and achieved a mean accuracy level of 91.3% and 92.5% in defining the size of the OD and PPA, respectively. Moreover, the correlation coefficient of the ground truth and the results from proposed method is 0.98 for both the PPA and OD.","PeriodicalId":440499,"journal":{"name":"2010 Biomedical Circuits and Systems Conference (BioCAS)","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128899443","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-11-01DOI: 10.1109/BIOCAS.2010.5709616
R. Singh, K. Abdelhalim, R. Genov
We present a simple, high-sensitivity, array-based capacitive sensing architecture for biological applications. Conventional charge based capacitance measurement (CBCM) techniques sense grounded coupling capacitances along with unwanted parasitics. These parasitics can be orders of magnitude higher than the coupling capacitances, thus severely reducing the usable sensor dynamic range. The presented architecture utilizes an accurate charge integration technique [1] to attenuate the effect of unwanted parasitics. Unlike CBCM, the architecture can also perform capacitance-voltage profiling of nonlinear biological capacitances at very low voltages. The architecture includes a first order ΔΣ modulator with dual input frequency to increase the sensor dynamic range. We verify the circuit implemented in a 0.35μm CMOS technology by simulating for different values of parasitic capacitances, process corners and varying test voltages across capacitors.
{"title":"A compact parasitic-insensitive dual-frequency ΔΣ modulated CMOS capacitive architecture","authors":"R. Singh, K. Abdelhalim, R. Genov","doi":"10.1109/BIOCAS.2010.5709616","DOIUrl":"https://doi.org/10.1109/BIOCAS.2010.5709616","url":null,"abstract":"We present a simple, high-sensitivity, array-based capacitive sensing architecture for biological applications. Conventional charge based capacitance measurement (CBCM) techniques sense grounded coupling capacitances along with unwanted parasitics. These parasitics can be orders of magnitude higher than the coupling capacitances, thus severely reducing the usable sensor dynamic range. The presented architecture utilizes an accurate charge integration technique [1] to attenuate the effect of unwanted parasitics. Unlike CBCM, the architecture can also perform capacitance-voltage profiling of nonlinear biological capacitances at very low voltages. The architecture includes a first order ΔΣ modulator with dual input frequency to increase the sensor dynamic range. We verify the circuit implemented in a 0.35μm CMOS technology by simulating for different values of parasitic capacitances, process corners and varying test voltages across capacitors.","PeriodicalId":440499,"journal":{"name":"2010 Biomedical Circuits and Systems Conference (BioCAS)","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126716267","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-11-01DOI: 10.1109/BIOCAS.2011.6107794
P. Degenaar, B. McGovern, R. Berlinguer-Palmini, N. Vysokov, N. Grossman, V. Pohrer, E. Drakakis, M. Neil
I Here we demonstrate the use of a micro-Light Emitting Diode Arrays as a powerful tool for complex spatiotemporal control of photosensitized neurons. The array can generate arbitrary, 2D, excitation patterns with millisecond and micrometer resolution. In particular, we describe an active matrix control address system to allow simultaneous control of 256 individual micro light emitting diodes. We present the system optically integrated into a microscope environment and patch clamp electrophysiology. The results show that the emitters have sufficient radiance at the required wavelength to stimulate neurons expressing channelrhodopsin-2 (ChR2).
{"title":"Individually addressable optoelectronic arrays for optogenetic neural stimulation","authors":"P. Degenaar, B. McGovern, R. Berlinguer-Palmini, N. Vysokov, N. Grossman, V. Pohrer, E. Drakakis, M. Neil","doi":"10.1109/BIOCAS.2011.6107794","DOIUrl":"https://doi.org/10.1109/BIOCAS.2011.6107794","url":null,"abstract":"I Here we demonstrate the use of a micro-Light Emitting Diode Arrays as a powerful tool for complex spatiotemporal control of photosensitized neurons. The array can generate arbitrary, 2D, excitation patterns with millisecond and micrometer resolution. In particular, we describe an active matrix control address system to allow simultaneous control of 256 individual micro light emitting diodes. We present the system optically integrated into a microscope environment and patch clamp electrophysiology. The results show that the emitters have sufficient radiance at the required wavelength to stimulate neurons expressing channelrhodopsin-2 (ChR2).","PeriodicalId":440499,"journal":{"name":"2010 Biomedical Circuits and Systems Conference (BioCAS)","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126066391","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-11-01DOI: 10.1109/BIOCAS.2010.5709631
Daniel Svard, A. Cichocki, A. Alvandpour
Electrophysiological signal acquisition such as ECG and EEG play an important part in modern medical monitoring and diagnostics. The measurement of these very low-level, low-frequency signals are normally made from the skin with a directly coupled sensor utilizing a conductive gel to create a low resistance path for the charge. The application of the gel is tedious and time consuming as well as requiring a clinical environment and prevents long period measurements. In this paper, a contact-less, capacitively coupled sensor — without any need for gel — together with an electronic readout circuit using a PCB is presented. A design with a very high input impedance allows for measurements of signals with amplitudes down to a few tens of microvolts and at frequencies between a few hertz to tens of hertz. Measurements show that the circuit could detect an input signal of 25 μV at 10 Hz with an SNR of 9.7 dB.
{"title":"Design and evaluation of a capacitively coupled sensor readout circuit, toward contact-less ECG and EEG","authors":"Daniel Svard, A. Cichocki, A. Alvandpour","doi":"10.1109/BIOCAS.2010.5709631","DOIUrl":"https://doi.org/10.1109/BIOCAS.2010.5709631","url":null,"abstract":"Electrophysiological signal acquisition such as ECG and EEG play an important part in modern medical monitoring and diagnostics. The measurement of these very low-level, low-frequency signals are normally made from the skin with a directly coupled sensor utilizing a conductive gel to create a low resistance path for the charge. The application of the gel is tedious and time consuming as well as requiring a clinical environment and prevents long period measurements. In this paper, a contact-less, capacitively coupled sensor — without any need for gel — together with an electronic readout circuit using a PCB is presented. A design with a very high input impedance allows for measurements of signals with amplitudes down to a few tens of microvolts and at frequencies between a few hertz to tens of hertz. Measurements show that the circuit could detect an input signal of 25 μV at 10 Hz with an SNR of 9.7 dB.","PeriodicalId":440499,"journal":{"name":"2010 Biomedical Circuits and Systems Conference (BioCAS)","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115298000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-06-02DOI: 10.1109/BIOCAS.2010.5709621
E. Neftci, G. Indiveri
Device mismatch in neuromorphic VLSI implementations of spiking neural networks can be a serious and limiting problem. Classical engineering solutions can reduce the effect of mismatch, but require increasing layout sizes or using additional precious silicon real-estate. Here we propose a complementary strategy which exploits the Address-Event Representation used in neuromorphic systems and does not affect the device layout. We propose a method that selectively changes the connectivity profile in the neural network to normalize its response. We provide a theoretical analysis of the approach proposed and demonstrate its effectiveness with experimental data obtained from a VLSI Soft Winner-Take-All network.
{"title":"A device mismatch compensation method for VLSI neural networks","authors":"E. Neftci, G. Indiveri","doi":"10.1109/BIOCAS.2010.5709621","DOIUrl":"https://doi.org/10.1109/BIOCAS.2010.5709621","url":null,"abstract":"Device mismatch in neuromorphic VLSI implementations of spiking neural networks can be a serious and limiting problem. Classical engineering solutions can reduce the effect of mismatch, but require increasing layout sizes or using additional precious silicon real-estate. Here we propose a complementary strategy which exploits the Address-Event Representation used in neuromorphic systems and does not affect the device layout. We propose a method that selectively changes the connectivity profile in the neural network to normalize its response. We provide a theoretical analysis of the approach proposed and demonstrate its effectiveness with experimental data obtained from a VLSI Soft Winner-Take-All network.","PeriodicalId":440499,"journal":{"name":"2010 Biomedical Circuits and Systems Conference (BioCAS)","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125062908","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1970-07-01DOI: 10.1109/peci.2011.5740482
{"title":"Copyright page","authors":"","doi":"10.1109/peci.2011.5740482","DOIUrl":"https://doi.org/10.1109/peci.2011.5740482","url":null,"abstract":"","PeriodicalId":440499,"journal":{"name":"2010 Biomedical Circuits and Systems Conference (BioCAS)","volume":"139 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1970-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115137496","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.1109/BIOCAS.2010.5709576
Shao-Yen Tseng, W. Fang
In this paper, a system for time-frequency analysis of heart rate variability (HRV) using a fast windowed Lomb periodogram is proposed. Time-frequency analysis of HRV is achieved through a de-normalized fast Lomb periodogram with a sliding window configuration. The Lomb time-frequency distribution (TFD) is suited for spectral analysis of unevenly spaced data and has been applied to the analysis of HRV. The system has been implemented in hardware as an HRV processor and verified on FPGA. Simulations show that the proposed Lomb TFD is able to achieve better frequency resolution than short-time Fourier transform of the same hardware size. The proposed system is suitable for portable monitoring devices and as a biomedical signal processor on an system-on-chip (SOC) design.
{"title":"An effective heart rate variability processor design based on time-frequency analysis algorithm using windowed Lomb periodogram","authors":"Shao-Yen Tseng, W. Fang","doi":"10.1109/BIOCAS.2010.5709576","DOIUrl":"https://doi.org/10.1109/BIOCAS.2010.5709576","url":null,"abstract":"In this paper, a system for time-frequency analysis of heart rate variability (HRV) using a fast windowed Lomb periodogram is proposed. Time-frequency analysis of HRV is achieved through a de-normalized fast Lomb periodogram with a sliding window configuration. The Lomb time-frequency distribution (TFD) is suited for spectral analysis of unevenly spaced data and has been applied to the analysis of HRV. The system has been implemented in hardware as an HRV processor and verified on FPGA. Simulations show that the proposed Lomb TFD is able to achieve better frequency resolution than short-time Fourier transform of the same hardware size. The proposed system is suitable for portable monitoring devices and as a biomedical signal processor on an system-on-chip (SOC) design.","PeriodicalId":440499,"journal":{"name":"2010 Biomedical Circuits and Systems Conference (BioCAS)","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128492424","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.1109/BIOCAS.2010.5709613
H. Hong, A. Demosthenous, I. Triantis, P. Langlois, R. Bayford
Advances in bioimpedance measurement applications need current drivers with high output impedance in the frequencies ranging from DC to a number of MHz. In particular, it needs greater than 10 MΩ output impedance at low frequencies, e.g., 10 kHz. This paper presents an current driver based on operational transconductance amplifiers (OTAs) using a feedback loop to provide over 10 MΩ output impedance ranging from DC to 10 kHz and 1 MΩ at 1 MHz. In addition, a stable performance over a wide frequency range (<4 MHz) is simulated. The circuit has been designed in a 0.6-μm CMOS process using ±2.5 V power supplies. Simulated results are presented.
{"title":"A high output impedance CMOS current driver for bioimpedance measurements","authors":"H. Hong, A. Demosthenous, I. Triantis, P. Langlois, R. Bayford","doi":"10.1109/BIOCAS.2010.5709613","DOIUrl":"https://doi.org/10.1109/BIOCAS.2010.5709613","url":null,"abstract":"Advances in bioimpedance measurement applications need current drivers with high output impedance in the frequencies ranging from DC to a number of MHz. In particular, it needs greater than 10 MΩ output impedance at low frequencies, e.g., 10 kHz. This paper presents an current driver based on operational transconductance amplifiers (OTAs) using a feedback loop to provide over 10 MΩ output impedance ranging from DC to 10 kHz and 1 MΩ at 1 MHz. In addition, a stable performance over a wide frequency range (<4 MHz) is simulated. The circuit has been designed in a 0.6-μm CMOS process using ±2.5 V power supplies. Simulated results are presented.","PeriodicalId":440499,"journal":{"name":"2010 Biomedical Circuits and Systems Conference (BioCAS)","volume":"110 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115025224","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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