Pub Date : 2016-01-04DOI: 10.1109/TBCAS.2015.2501359
Mohsen Shokouhian, R. Morling, I. Kale
Ambient light and optical interference can severely affect the performance of pulse oximeters. The deployment of a robust modulation technique to drive the pulse oximeter LEDs can reduce these unwanted effects and increases the resilient of the pulse oximeter against artificial ambient light. The time division modulation technique used in conventional pulse oximeters can not remove the effect of modulated light coming from surrounding environment and this may cause huge measurement error in pulse oximeter readings. This paper presents a novel cross-coupled sigma delta modulator which ensures that measurement accuracy will be more robust in comparison with conventional fixed-frequency oximeter modulation technique especially in the presence of pulsed artificial ambient light. Moreover, this novel modulator gives an extra control over the pulse oximeter power consumption leading to improved power management.
{"title":"Interference Resilient Sigma Delta-Based Pulse Oximeter","authors":"Mohsen Shokouhian, R. Morling, I. Kale","doi":"10.1109/TBCAS.2015.2501359","DOIUrl":"https://doi.org/10.1109/TBCAS.2015.2501359","url":null,"abstract":"Ambient light and optical interference can severely affect the performance of pulse oximeters. The deployment of a robust modulation technique to drive the pulse oximeter LEDs can reduce these unwanted effects and increases the resilient of the pulse oximeter against artificial ambient light. The time division modulation technique used in conventional pulse oximeters can not remove the effect of modulated light coming from surrounding environment and this may cause huge measurement error in pulse oximeter readings. This paper presents a novel cross-coupled sigma delta modulator which ensures that measurement accuracy will be more robust in comparison with conventional fixed-frequency oximeter modulation technique especially in the presence of pulsed artificial ambient light. Moreover, this novel modulator gives an extra control over the pulse oximeter power consumption leading to improved power management.","PeriodicalId":13151,"journal":{"name":"IEEE Transactions on Biomedical Circuits and Systems","volume":null,"pages":null},"PeriodicalIF":5.1,"publicationDate":"2016-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1109/TBCAS.2015.2501359","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62965201","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-12-29DOI: 10.1109/TBCAS.2015.2500911
Jin-Hong Ahn, Sang-Hoon Hong, Youngjune Park
This paper presents a double-side CMOS-carbon nanotube (CNT) sensor array for simple bare-die measurements in a medical environment based on a 0.35 μm standard CMOS process. This scheme allows robust measurements due to its inherent back-side rectifying diodes with a high latch-up resistance. In particular, instead of using pads, only two contact metal structures: a wide ring structure around the sensor area on the front side and a plate structure at the backside are used for both power and single I/O line. The back-side rectification is made possible by creating VDD and VSS through the back-side and front-side, respectively. The single I/O line is conditioned such that it doubles as either the power source or the ground, depending on whether the chip is face down or face up. A modified universal asynchronous receiver/transmitter (UART) serial communication scheme with pulse based I/O signal transmission is developed to reduce the power degradation during the signaling intervals. In addition, communication errors and I/O power dissipation for the receiver path are minimized by using level sensitive switch control and double sampling difference amplifier. In order to implement these special functions, a controller chip with a special I/O protocol is designed. Using this controller chip, issuing commands and receiving data can both be performed on a single line and the results are flexibly measured through either the backside or the front side of the chip contacts. As a result, a stable operation of under 150 mW maximum power at 2 MHz data rate can be achieved. The double-side chips with 32 × 32 and 64 × 64 sensor arrays occupy areas of 1.9×2.3 mm2 and 3.7×3.9 mm2, respectively.
{"title":"A Double-Side CMOS-CNT Biosensor Array With Padless Structure for Simple Bare-Die Measurements in a Medical Environment","authors":"Jin-Hong Ahn, Sang-Hoon Hong, Youngjune Park","doi":"10.1109/TBCAS.2015.2500911","DOIUrl":"https://doi.org/10.1109/TBCAS.2015.2500911","url":null,"abstract":"This paper presents a double-side CMOS-carbon nanotube (CNT) sensor array for simple bare-die measurements in a medical environment based on a 0.35 μm standard CMOS process. This scheme allows robust measurements due to its inherent back-side rectifying diodes with a high latch-up resistance. In particular, instead of using pads, only two contact metal structures: a wide ring structure around the sensor area on the front side and a plate structure at the backside are used for both power and single I/O line. The back-side rectification is made possible by creating VDD and VSS through the back-side and front-side, respectively. The single I/O line is conditioned such that it doubles as either the power source or the ground, depending on whether the chip is face down or face up. A modified universal asynchronous receiver/transmitter (UART) serial communication scheme with pulse based I/O signal transmission is developed to reduce the power degradation during the signaling intervals. In addition, communication errors and I/O power dissipation for the receiver path are minimized by using level sensitive switch control and double sampling difference amplifier. In order to implement these special functions, a controller chip with a special I/O protocol is designed. Using this controller chip, issuing commands and receiving data can both be performed on a single line and the results are flexibly measured through either the backside or the front side of the chip contacts. As a result, a stable operation of under 150 mW maximum power at 2 MHz data rate can be achieved. The double-side chips with 32 × 32 and 64 × 64 sensor arrays occupy areas of 1.9×2.3 mm2 and 3.7×3.9 mm2, respectively.","PeriodicalId":13151,"journal":{"name":"IEEE Transactions on Biomedical Circuits and Systems","volume":null,"pages":null},"PeriodicalIF":5.1,"publicationDate":"2015-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1109/TBCAS.2015.2500911","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62965116","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-12-28DOI: 10.1109/TBCAS.2015.2498643
Abhishek Roy, Alicia Klinefelter, Farah B. Yahya, Xing Chen, Luis Gonzalez-Guerrero, Christopher J. Lukas, Divya Akella, James Boley, Kyle Craig, M. Faisal, Seunghyun Oh, N. Roberts, Y. Shakhsheer, A. Shrivastava, D. Vasudevan, D. Wentzloff, B. Calhoun
This paper presents a batteryless system-on-chip (SoC) that operates off energy harvested from indoor solar cells and/or thermoelectric generators (TEGs) on the body. Fabricated in a commercial 0.13 μW process, this SoC sensing platform consists of an integrated energy harvesting and power management unit (EH-PMU) with maximum power point tracking, multiple sensing modalities, programmable core and a low power microcontroller with several hardware accelerators to enable energy-efficient digital signal processing, ultra-low-power (ULP) asymmetric radios for wireless transmission, and a 100 nW wake-up radio. The EH-PMU achieves a peak end-to-end efficiency of 75% delivering power to a 100 μA load. In an example motion detection application, the SoC reads data from an accelerometer through SPI, processes it, and sends it over the radio. The SPI and digital processing consume only 2.27 μW, while the integrated radio consumes 4.18 μW when transmitting at 187.5 kbps for a total of 6.45 μW.
{"title":"A 6.45 $mu{rm W}$ Self-Powered SoC With Integrated Energy-Harvesting Power Management and ULP Asymmetric Radios for Portable Biomedical Systems","authors":"Abhishek Roy, Alicia Klinefelter, Farah B. Yahya, Xing Chen, Luis Gonzalez-Guerrero, Christopher J. Lukas, Divya Akella, James Boley, Kyle Craig, M. Faisal, Seunghyun Oh, N. Roberts, Y. Shakhsheer, A. Shrivastava, D. Vasudevan, D. Wentzloff, B. Calhoun","doi":"10.1109/TBCAS.2015.2498643","DOIUrl":"https://doi.org/10.1109/TBCAS.2015.2498643","url":null,"abstract":"This paper presents a batteryless system-on-chip (SoC) that operates off energy harvested from indoor solar cells and/or thermoelectric generators (TEGs) on the body. Fabricated in a commercial 0.13 μW process, this SoC sensing platform consists of an integrated energy harvesting and power management unit (EH-PMU) with maximum power point tracking, multiple sensing modalities, programmable core and a low power microcontroller with several hardware accelerators to enable energy-efficient digital signal processing, ultra-low-power (ULP) asymmetric radios for wireless transmission, and a 100 nW wake-up radio. The EH-PMU achieves a peak end-to-end efficiency of 75% delivering power to a 100 μA load. In an example motion detection application, the SoC reads data from an accelerometer through SPI, processes it, and sends it over the radio. The SPI and digital processing consume only 2.27 μW, while the integrated radio consumes 4.18 μW when transmitting at 187.5 kbps for a total of 6.45 μW.","PeriodicalId":13151,"journal":{"name":"IEEE Transactions on Biomedical Circuits and Systems","volume":null,"pages":null},"PeriodicalIF":5.1,"publicationDate":"2015-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1109/TBCAS.2015.2498643","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62964930","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-12-28DOI: 10.1109/TBCAS.2015.2500101
Zhuo Wang, Jintao Zhang, N. Verma
In wearable and implantable medical-sensor applications, low-energy classification systems are of importance for deriving high-quality inferences locally within the device. Given that sensor instrumentation is typically followed by A-D conversion, this paper presents a system implementation wherein the majority of the computations required for classification are implemented within the ADC. To achieve this, first an algorithmic formulation is presented that combines linear feature extraction and classification into a single matrix transformation. Second, a matrix-multiplying ADC (MMADC) is presented that enables multiplication between an analog input sample and a digital multiplier, with negligible additional energy beyond that required for A-D conversion. Two systems mapped to the MMADC are demonstrated: (1) an ECG-based cardiac arrhythmia detector; and (2) an image-pixel-based facial gender detector. The RMS error over all multiplication performed, normalized to the RMS of ideal multiplication results is 0.018. Further, compared to idealized versions of conventional systems, the energy savings obtained are estimated to be 13× and 29×, respectively, while achieving similar level of performance.
{"title":"Realizing Low-Energy Classification Systems by Implementing Matrix Multiplication Directly Within an ADC","authors":"Zhuo Wang, Jintao Zhang, N. Verma","doi":"10.1109/TBCAS.2015.2500101","DOIUrl":"https://doi.org/10.1109/TBCAS.2015.2500101","url":null,"abstract":"In wearable and implantable medical-sensor applications, low-energy classification systems are of importance for deriving high-quality inferences locally within the device. Given that sensor instrumentation is typically followed by A-D conversion, this paper presents a system implementation wherein the majority of the computations required for classification are implemented within the ADC. To achieve this, first an algorithmic formulation is presented that combines linear feature extraction and classification into a single matrix transformation. Second, a matrix-multiplying ADC (MMADC) is presented that enables multiplication between an analog input sample and a digital multiplier, with negligible additional energy beyond that required for A-D conversion. Two systems mapped to the MMADC are demonstrated: (1) an ECG-based cardiac arrhythmia detector; and (2) an image-pixel-based facial gender detector. The RMS error over all multiplication performed, normalized to the RMS of ideal multiplication results is 0.018. Further, compared to idealized versions of conventional systems, the energy savings obtained are estimated to be 13× and 29×, respectively, while achieving similar level of performance.","PeriodicalId":13151,"journal":{"name":"IEEE Transactions on Biomedical Circuits and Systems","volume":null,"pages":null},"PeriodicalIF":5.1,"publicationDate":"2015-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1109/TBCAS.2015.2500101","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62965000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-12-01DOI: 10.1109/TBCAS.2015.2504563
Seongwook Park, Junyoung Park, Kyeongryeol Bong, Dongjoo Shin, Jinmook Lee, Sungpill Choi, H. Yoo
Deep Learning algorithm is widely used for various pattern recognition applications such as text recognition, object recognition and action recognition because of its best-in-class recognition accuracy compared to hand-crafted algorithm and shallow learning based algorithms. Long learning time caused by its complex structure, however, limits its usage only in high-cost servers or many-core GPU platforms so far. On the other hand, the demand on customized pattern recognition within personal devices will grow gradually as more deep learning applications will be developed. This paper presents a SoC implementation to enable deep learning applications to run with low cost platforms such as mobile or portable devices. Different from conventional works which have adopted massively-parallel architecture, this work adopts task-flexible architecture and exploits multiple parallelism to cover complex functions of convolutional deep belief network which is one of popular deep learning/inference algorithms. In this paper, we implement the most energy-efficient deep learning and inference processor for wearable system. The implemented 2.5 mm ×4.0 mm deep learning/inference processor is fabricated using 65 nm 8-metal CMOS technology for a battery-powered platform with real-time deep inference and deep learning operation. It consumes 185 mW average power, and 213.1 mW peak power at 200 MHz operating frequency and 1.2 V supply voltage. It achieves 411.3 GOPS peak performance and 1.93 TOPS/W energy efficiency, which is 2.07× higher than the state-of-the-art.
深度学习算法被广泛用于各种模式识别应用，如文本识别、对象识别和动作识别，因为与手工算法和基于浅学习的算法相比，深度学习算法具有同类最佳的识别精度。但由于其结构复杂，学习时间长，目前仅局限于高成本服务器或多核GPU平台。另一方面，随着更多深度学习应用的开发，个人设备对定制模式识别的需求将逐渐增长。本文提出了一个SoC实现，使深度学习应用程序能够在低成本平台(如移动或便携式设备)上运行。与传统的大规模并行架构不同，本文采用了任务柔性架构，利用多重并行性覆盖了卷积深度信念网络的复杂功能，卷积深度信念网络是目前流行的深度学习/推理算法之一。在本文中，我们为可穿戴系统实现了最节能的深度学习和推理处理器。实现的2.5 mm ×4.0 mm深度学习/推理处理器采用65 nm 8金属CMOS技术制造，用于具有实时深度推理和深度学习操作的电池供电平台。在200mhz工作频率和1.2 V电源电压下，平均功耗为185mw，峰值功耗为213.1 mW。峰值性能达到411.3 GOPS，能效达到1.93 TOPS/W，比目前先进水平提高2.07倍。
{"title":"An Energy-Efficient and Scalable Deep Learning/Inference Processor With Tetra-Parallel MIMD Architecture for Big Data Applications","authors":"Seongwook Park, Junyoung Park, Kyeongryeol Bong, Dongjoo Shin, Jinmook Lee, Sungpill Choi, H. Yoo","doi":"10.1109/TBCAS.2015.2504563","DOIUrl":"https://doi.org/10.1109/TBCAS.2015.2504563","url":null,"abstract":"Deep Learning algorithm is widely used for various pattern recognition applications such as text recognition, object recognition and action recognition because of its best-in-class recognition accuracy compared to hand-crafted algorithm and shallow learning based algorithms. Long learning time caused by its complex structure, however, limits its usage only in high-cost servers or many-core GPU platforms so far. On the other hand, the demand on customized pattern recognition within personal devices will grow gradually as more deep learning applications will be developed. This paper presents a SoC implementation to enable deep learning applications to run with low cost platforms such as mobile or portable devices. Different from conventional works which have adopted massively-parallel architecture, this work adopts task-flexible architecture and exploits multiple parallelism to cover complex functions of convolutional deep belief network which is one of popular deep learning/inference algorithms. In this paper, we implement the most energy-efficient deep learning and inference processor for wearable system. The implemented 2.5 mm ×4.0 mm deep learning/inference processor is fabricated using 65 nm 8-metal CMOS technology for a battery-powered platform with real-time deep inference and deep learning operation. It consumes 185 mW average power, and 213.1 mW peak power at 200 MHz operating frequency and 1.2 V supply voltage. It achieves 411.3 GOPS peak performance and 1.93 TOPS/W energy efficiency, which is 2.07× higher than the state-of-the-art.","PeriodicalId":13151,"journal":{"name":"IEEE Transactions on Biomedical Circuits and Systems","volume":null,"pages":null},"PeriodicalIF":5.1,"publicationDate":"2015-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1109/TBCAS.2015.2504563","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62966130","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-12-01DOI: 10.1109/TBCAS.2015.2507618
Po-Hung Kuo, Jui-Chang Kuo, Hsiao-Ting Hsueh, J. Hsieh, Yi-Chun Huang, Tao Wang, Yen-Hung Lin, Chih-Ting Lin, Yao-Joe Yang, Shey-Shi Lu
A micro-controller unit (MCU) assisted immunoassay lab-on-a-chip is realized in 0.35 μm CMOS technology. The MCU automatically controls the detection procedure including blood filtration through a nonporous aluminum oxide membrane, bimolecular conjugation with antibodies attached to magnetic beads, electrolytic pumping, magnetic flushing and threshold detection based on Hall sensor array readout analysis. To verify the function of this chip, in-vitro Tumor necrosis factor- α (TNF- α) and N-terminal pro-brain natriuretic peptide (NT-proBNP) tests are performed by this 9 mm 2-sized single chip. The cost, efficiency and portability are considerably improved compared to the prior art.
{"title":"A Smart CMOS Assay SoC for Rapid Blood Screening Test of Risk Prediction","authors":"Po-Hung Kuo, Jui-Chang Kuo, Hsiao-Ting Hsueh, J. Hsieh, Yi-Chun Huang, Tao Wang, Yen-Hung Lin, Chih-Ting Lin, Yao-Joe Yang, Shey-Shi Lu","doi":"10.1109/TBCAS.2015.2507618","DOIUrl":"https://doi.org/10.1109/TBCAS.2015.2507618","url":null,"abstract":"A micro-controller unit (MCU) assisted immunoassay lab-on-a-chip is realized in 0.35 μm CMOS technology. The MCU automatically controls the detection procedure including blood filtration through a nonporous aluminum oxide membrane, bimolecular conjugation with antibodies attached to magnetic beads, electrolytic pumping, magnetic flushing and threshold detection based on Hall sensor array readout analysis. To verify the function of this chip, in-vitro Tumor necrosis factor- α (TNF- α) and N-terminal pro-brain natriuretic peptide (NT-proBNP) tests are performed by this 9 mm 2-sized single chip. The cost, efficiency and portability are considerably improved compared to the prior art.","PeriodicalId":13151,"journal":{"name":"IEEE Transactions on Biomedical Circuits and Systems","volume":null,"pages":null},"PeriodicalIF":5.1,"publicationDate":"2015-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1109/TBCAS.2015.2507618","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62965698","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-12-01DOI: 10.1109/TBCAS.2015.2501320
A. Donida, G. Dato, Paolo Cunzolo, M. Sala, Filippo Piffaretti, P. Orsatti, D. Barrettino
This paper presents a new system to measure the Intraocular Pressure (IOP) with very high accuracy (0.036 mbar) used for monitoring glaucoma. The system not only monitors the daily variation of the IOP (circadian IOP), but also allows to perform an spectral analysis of the pressure signal generated by the heartbeat (cardiac IOP). The system comprises a piezoresistive pressure sensor, an application-specific integrated circuit (ASIC) to read out the sensor data and an external reader installed on customized glasses. The ASIC readout electronics combines chopping modulation with correlated double sampling (CDS) in order to eliminate both the amplifier offset and the chopper ripple at the sampling frequency. In addition, programmable current sources are used to compensate for the atmospheric pressure ( 800-1200 mbar ) and the circadian component ( ±7 mbar) thus allowing to read out the very weak cardiac signals ( ±1.6 mbar) with a maximum accuracy of 0.036 mbar.
{"title":"A Circadian and Cardiac Intraocular Pressure Sensor for Smart Implantable Lens","authors":"A. Donida, G. Dato, Paolo Cunzolo, M. Sala, Filippo Piffaretti, P. Orsatti, D. Barrettino","doi":"10.1109/TBCAS.2015.2501320","DOIUrl":"https://doi.org/10.1109/TBCAS.2015.2501320","url":null,"abstract":"This paper presents a new system to measure the Intraocular Pressure (IOP) with very high accuracy (0.036 mbar) used for monitoring glaucoma. The system not only monitors the daily variation of the IOP (circadian IOP), but also allows to perform an spectral analysis of the pressure signal generated by the heartbeat (cardiac IOP). The system comprises a piezoresistive pressure sensor, an application-specific integrated circuit (ASIC) to read out the sensor data and an external reader installed on customized glasses. The ASIC readout electronics combines chopping modulation with correlated double sampling (CDS) in order to eliminate both the amplifier offset and the chopper ripple at the sampling frequency. In addition, programmable current sources are used to compensate for the atmospheric pressure ( 800-1200 mbar ) and the circadian component ( ±7 mbar) thus allowing to read out the very weak cardiac signals ( ±1.6 mbar) with a maximum accuracy of 0.036 mbar.","PeriodicalId":13151,"journal":{"name":"IEEE Transactions on Biomedical Circuits and Systems","volume":null,"pages":null},"PeriodicalIF":5.1,"publicationDate":"2015-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1109/TBCAS.2015.2501320","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62965192","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-12-01DOI: 10.1109/TBCAS.2015.2508439
Hao-Yen Tang, D. Seo, Utkarsh Singhal, Xi Li, M. Maharbiz, E. Alon, B. Boser
We present a miniaturized portable ultrasonic imager that uses a custom ASIC and a piezoelectric transducer array to transmit and capture 2-D sonographs. The ASIC, fabricated in 0.18 μm 32 V CMOS process, contains 7 identical channels, each with high-voltage level-shifters, high-voltage DC-DC converters, digital TX beamformer, and RX front-end. The chip is powered by a single 1.8 V supply and generates 5 V and 32 V internally using on-chip charge pumps with an efficiency of 33% to provide 32 V pulses for driving a bulk piezoelectric transducer array. The assembled prototype can operate up to 40 MHz, with beamformer delay resolution of 5 ns, and has a measured sensitivity of 225 nV/Pa , minimum detectable signal of 622 Pa assuming 12 dB SNR ( 4σ larger than the noise level), and data acquisition time of 21.3 ms. The system can image human tissue as deep as 5 cm while consuming less than 16.5 μJ per pulse-echo measurement. The high energy efficiency of the imager can enable a number of consumer applications.
{"title":"Miniaturizing Ultrasonic System for Portable Health Care and Fitness","authors":"Hao-Yen Tang, D. Seo, Utkarsh Singhal, Xi Li, M. Maharbiz, E. Alon, B. Boser","doi":"10.1109/TBCAS.2015.2508439","DOIUrl":"https://doi.org/10.1109/TBCAS.2015.2508439","url":null,"abstract":"We present a miniaturized portable ultrasonic imager that uses a custom ASIC and a piezoelectric transducer array to transmit and capture 2-D sonographs. The ASIC, fabricated in 0.18 μm 32 V CMOS process, contains 7 identical channels, each with high-voltage level-shifters, high-voltage DC-DC converters, digital TX beamformer, and RX front-end. The chip is powered by a single 1.8 V supply and generates 5 V and 32 V internally using on-chip charge pumps with an efficiency of 33% to provide 32 V pulses for driving a bulk piezoelectric transducer array. The assembled prototype can operate up to 40 MHz, with beamformer delay resolution of 5 ns, and has a measured sensitivity of 225 nV/Pa , minimum detectable signal of 622 Pa assuming 12 dB SNR ( 4σ larger than the noise level), and data acquisition time of 21.3 ms. The system can image human tissue as deep as 5 cm while consuming less than 16.5 μJ per pulse-echo measurement. The high energy efficiency of the imager can enable a number of consumer applications.","PeriodicalId":13151,"journal":{"name":"IEEE Transactions on Biomedical Circuits and Systems","volume":null,"pages":null},"PeriodicalIF":5.1,"publicationDate":"2015-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1109/TBCAS.2015.2508439","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62965749","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-12-01DOI: 10.1109/TBCAS.2015.2501816
M. Bakhshiani, M. Suster, P. Mohseni
This paper presents a fully integrated transceiver IC as part of a self-sustained, microfluidic-CMOS platform for miniaturized dielectric spectroscopy (DS) from MHz to GHz. Fabricated in AMS 0.35 μm 2P/4M RF CMOS, the transmitter (TX) part of the IC generates a single-tone sinusoidal signal with frequency tunability in the range of to excite a three-dimensional (3D), parallel-plate, capacitive sensor with a floating electrode and 9 μL microfluidic channel for sample delivery. With a material-under-test (MUT) loaded into the sensor, the receiver (RX) part of the IC employs broadband frequency response analysis (bFRA) methodology to measure the amplitude and phase of the RF excitation signal after transmission through the sensor. A one-time, 6-point sensor calibration algorithm then extracts both the real and imaginary parts of the MUT complex permittivity, εr, from IC measurements of the sensor transmission characteristics in the voltage domain. The “sensor + IC” is fully capable of differentiating among de-ionized (DI) water, phosphate-buffered saline (PBS), and alcoholic beverages in tests conducted at four excitation frequencies of ~ 50 MHz, 500 MHz, 1.5 GHz, and 2.4 GHz generated by the TX. Moreover, permittivity readings of PBS by the sensor interfaced with the IC at six excitation frequencies in the range of are in excellent agreement (rms error of 1.7% (real) and 7.2% (imaginary)) with those from bulk-solution reference measurements by commercial benchtop equipment. The total power consumption of the IC is with 1.5 V (analog) and 3.3 V (digital) supplies.
{"title":"A 9 MHz–2.4 GHz Fully Integrated Transceiver IC for a Microfluidic-CMOS Platform Dedicated to Miniaturized Dielectric Spectroscopy","authors":"M. Bakhshiani, M. Suster, P. Mohseni","doi":"10.1109/TBCAS.2015.2501816","DOIUrl":"https://doi.org/10.1109/TBCAS.2015.2501816","url":null,"abstract":"This paper presents a fully integrated transceiver IC as part of a self-sustained, microfluidic-CMOS platform for miniaturized dielectric spectroscopy (DS) from MHz to GHz. Fabricated in AMS 0.35 μm 2P/4M RF CMOS, the transmitter (TX) part of the IC generates a single-tone sinusoidal signal with frequency tunability in the range of to excite a three-dimensional (3D), parallel-plate, capacitive sensor with a floating electrode and 9 μL microfluidic channel for sample delivery. With a material-under-test (MUT) loaded into the sensor, the receiver (RX) part of the IC employs broadband frequency response analysis (bFRA) methodology to measure the amplitude and phase of the RF excitation signal after transmission through the sensor. A one-time, 6-point sensor calibration algorithm then extracts both the real and imaginary parts of the MUT complex permittivity, εr, from IC measurements of the sensor transmission characteristics in the voltage domain. The “sensor + IC” is fully capable of differentiating among de-ionized (DI) water, phosphate-buffered saline (PBS), and alcoholic beverages in tests conducted at four excitation frequencies of ~ 50 MHz, 500 MHz, 1.5 GHz, and 2.4 GHz generated by the TX. Moreover, permittivity readings of PBS by the sensor interfaced with the IC at six excitation frequencies in the range of are in excellent agreement (rms error of 1.7% (real) and 7.2% (imaginary)) with those from bulk-solution reference measurements by commercial benchtop equipment. The total power consumption of the IC is with 1.5 V (analog) and 3.3 V (digital) supplies.","PeriodicalId":13151,"journal":{"name":"IEEE Transactions on Biomedical Circuits and Systems","volume":null,"pages":null},"PeriodicalIF":5.1,"publicationDate":"2015-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1109/TBCAS.2015.2501816","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62965229","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-12-01DOI: 10.1109/TBCAS.2015.2503418
Xing Li, Xiaodong Meng, C. Tsui, W. Ki
Wireless power transfer using reconfigurable resonant regulating ( R3) rectification suffers from limited range in accommodating varying coupling and loading conditions. A primary-assisted regulation principle is proposed to mitigate these limitations, of which the amplitude of the rectifier input voltage on the secondary side is regulated by accordingly adjusting the voltage amplitude Veq on the primary side. A novel current-sensing method and calibration scheme track Veq on the primary side. A ramp generator simultaneously provides three clock signals for different modules. Both the primary equalizer and the R3 rectifier are implemented as custom integrated circuits fabricated in a 0.35 μm CMOS process, with the global control implemented in FPGA. Measurements show that with the primary equalizer, the workable coupling and loading ranges are extended by 250% at 120 mW load and 300% at 1.2 cm coil distance compared to the same system without the primary equalizer. A maximum rectifier efficiency of 92.5% and a total system efficiency of 62.4% are demonstrated.
{"title":"Reconfigurable Resonant Regulating Rectifier With Primary Equalization for Extended Coupling- and Loading-Range in Bio-Implant Wireless Power Transfer","authors":"Xing Li, Xiaodong Meng, C. Tsui, W. Ki","doi":"10.1109/TBCAS.2015.2503418","DOIUrl":"https://doi.org/10.1109/TBCAS.2015.2503418","url":null,"abstract":"Wireless power transfer using reconfigurable resonant regulating ( R3) rectification suffers from limited range in accommodating varying coupling and loading conditions. A primary-assisted regulation principle is proposed to mitigate these limitations, of which the amplitude of the rectifier input voltage on the secondary side is regulated by accordingly adjusting the voltage amplitude Veq on the primary side. A novel current-sensing method and calibration scheme track Veq on the primary side. A ramp generator simultaneously provides three clock signals for different modules. Both the primary equalizer and the R3 rectifier are implemented as custom integrated circuits fabricated in a 0.35 μm CMOS process, with the global control implemented in FPGA. Measurements show that with the primary equalizer, the workable coupling and loading ranges are extended by 250% at 120 mW load and 300% at 1.2 cm coil distance compared to the same system without the primary equalizer. A maximum rectifier efficiency of 92.5% and a total system efficiency of 62.4% are demonstrated.","PeriodicalId":13151,"journal":{"name":"IEEE Transactions on Biomedical Circuits and Systems","volume":null,"pages":null},"PeriodicalIF":5.1,"publicationDate":"2015-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1109/TBCAS.2015.2503418","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62966122","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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