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Jenshan Lin - One of the best experts on this subject based on the ideXlab platform.
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authors reply to respiration rate measurement under 1 d body motion using single continuous wave doppler radar Vital Sign detection system
IEEE Transactions on Microwave Theory and Techniques, 2019Co-Authors: Taesong Hwang, Jenshan LinAbstract:Random body movement (RBM) is one of the most challenging issues in non-contact Vital Sign detection using Doppler radar technique. The large and irregular displacement of the human body could corrupt the Vital Sign Signal and Significantly degrade the accuracy of detection. Even the respiration rate (RR) sometimes cannot be measured accurately under RBM. In this paper, the characteristic of the frequency spectrum of the Vital Sign Signal under body motion (the motion modulation effect) is analyzed. Based on that effect, an RR measurement method under one-dimensional (1-D) body motion is developed using only one non-contact continuous-wave (CW) Doppler radar Vital Sign detection system. The direction of body motion is extracted along with the new position of the respiration peaks in the frequency spectrum and RR can be calculated. Simulations of the theory using a model of the Vital Sign detection system are performed, followed by experiments to verify the theory. Experiments are performed on an actuator and a human subject by only one 5.8-GHz non-contact CW Vital Sign detection system. Under large 1-D body motion that has a displacement 5–10 times larger than the respiratory displacement, the proposed method successfully measures RR with only 7.15% error.
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fast acquisition of heart rate in noncontact Vital Sign radar measurement using time window variation technique
IEEE Transactions on Instrumentation and Measurement, 2016Co-Authors: Jenshan LinAbstract:The fast acquisition of heart rate (HR) is a challenge in noncontact Vital Sign detection using a Doppler radar system. Most of the previous studies use long-period time windows to guarantee a sufficient frequency spectrum resolution for HR measurement using the peak searching method on the frequency spectrum. For fast acquisition of HR, the length of the time window is less than 5 s and the accuracy is Significantly degraded due to insufficient spectrum resolution. For Vital Sign detection using complex Signal demodulation (CSD), measuring HR variation becomes a difficult job due to respiration harmonic interference and insufficient frequency spectrum resolution. In this paper, a time-window-variation technique is developed for fast acquisition of HR from short-period time windows and measuring HR variation using CSD. Experiments are performed on four human subjects under controlled laboratory conditions by a 5.8-GHz continuous-wave Doppler radar Vital Sign detection system. The HR measurement results within 2–5-s time windows are compared by applying a simple fast Fourier transform (FFT) and peak searching method, a 10-s sliding-time-window FFT method, and the proposed method. The proposed method achieves the smallest average error among the three techniques. The proposed method has also proved to be able to measure HR variation using CSD.
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Vital Sign radars: Past, present, and future
WAMICON 2014, 2014Co-Authors: Jenshan LinAbstract:The research of Vital Sign radars using microwave technologies grows rapidly in recent years. Such type of radars, whether using continuous-wave (CW), ultra-wideband (UWB), or other types of Signals, spurred interests and new applications because of the capability of detecting respiration and heartbeat without any sensor device contacting the body. Several applications that may potentially save lives or improve healthcare have been suggested. Since 1975 when the experimental demonstration of this noncontact Vital Sign detection concept was first reported, it has been nearly 40 years. One might be wondering what have been achieved in the past four decades, why this technology has not been transformed to real products around us, and what might happen next. This presentation intends to address the questions by reviewing the past research accomplishments of Vital Sign radars and envisioning the future trends in both research and commercialization.
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respiration harmonics cancellation for accurate heart rate measurement in non contact Vital Sign detection
International Microwave Symposium, 2013Co-Authors: Jenshan LinAbstract:Measuring the respiration rate (RR) and heart rate (HR) simultaneously in non-contact Vital Sign detection requires large dynamic range which is caused by large difference in respiratory and heart induced displacements. Generated by the demodulation method and displacements, the higher order harmonics of RR near HR might appear and cause error in HR measurement. A respiration harmonics cancellation method is proposed to eliminate the interference. Experiments are performed by a 5.8-GHz non-contact Doppler radar Vital Sign detection system with an S12 Any-Touch ECG-Accurate Heart Rate Monitor as the reference to verify the method. HR is measured by searching the highest peak within the typical HR range in the frequency spectrum. Results of HR measurement with and without the respiration harmonics cancellation method are compared. When the harmonics of the respiration Signal are strong, using the respiration harmonics cancellation method reduces the average error from 15.9% to 3.2%.
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high sensitivity software configurable 5 8 ghz radar sensor receiver chip in 0 13 mu m cmos for noncontact Vital Sign detection
IEEE Transactions on Microwave Theory and Techniques, 2010Co-Authors: Chienming Lee, Lixin Ran, Jenshan LinAbstract:In this paper, analyses on sensitivity and link budget have been presented to guide the deSign of high-sensitivity noncontact Vital Sign detector. Important deSign issues such as flicker noise, baseband bandwidth, and gain budget have been discussed with practical considerations of analog-to-digital interface and Signal processing methods in noncontact Vital Sign detection. Based on the analyses, a direct-conversion 5.8-GHz radar sensor chip with 1-GHz bandwidth was deSigned and fabricated. This radar sensor chip is software configurable to set the operation point and detection range for optimal performance. It integrates all the analog functions on-chip so that the output can be directly sampled for digital Signal processing. Measurement results show that the fabricated chip has a sensitivity of better than -101 dBm for ideal detection in the absence of random body movement. Experiments have been performed successfully in laboratory environment to detect the Vital Signs of human subjects.
João Paulo Silva Cunha - One of the best experts on this subject based on the ideXlab platform.
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wearable health devices Vital Sign monitoring systems and technologies
Sensors, 2018Co-Authors: Duarte Dias, João Paulo Silva CunhaAbstract:Wearable Health Devices (WHDs) are increasingly helping people to better monitor their health status both at an activity/fitness level for self-health tracking and at a medical level providing more data to clinicians with a potential for earlier diagnostic and guidance of treatment. The technology revolution in the miniaturization of electronic devices is enabling to deSign more reliable and adaptable wearables, contributing for a world-wide change in the health monitoring approach. In this paper we review important aspects in the WHDs area, listing the state-of-the-art of wearable Vital Signs sensing technologies plus their system architectures and specifications. A focus on Vital Signs acquired by WHDs is made: first a discussion about the most important Vital Signs for health assessment using WHDs is presented and then for each Vital Sign a description is made concerning its origin and effect on heath, monitoring needs, acquisition methods and WHDs and recent scientific developments on the area (electrocardiogram, heart rate, blood pressure, respiration rate, blood oxygen saturation, blood glucose, skin perspiration, capnography, body temperature, motion evaluation, cardiac implantable devices and ambient parameters). A general WHDs system architecture is presented based on the state-of-the-art. After a global review of WHDs, we zoom in into cardiovascular WHDs, analysing commercial devices and their applicability versus quality, extending this subject to smart t-shirts for medical purposes. Furthermore we present a resumed evolution of these devices based on the prototypes developed along the years. Finally we discuss likely market trends and future challenges for the emerging WHDs area.
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Wearable Health Devices—Vital Sign Monitoring, Systems and Technologies
MDPI AG, 2018Co-Authors: Duarte Dias, João Paulo Silva CunhaAbstract:Wearable Health Devices (WHDs) are increasingly helping people to better monitor their health status both at an activity/fitness level for self-health tracking and at a medical level providing more data to clinicians with a potential for earlier diagnostic and guidance of treatment. The technology revolution in the miniaturization of electronic devices is enabling to deSign more reliable and adaptable wearables, contributing for a world-wide change in the health monitoring approach. In this paper we review important aspects in the WHDs area, listing the state-of-the-art of wearable Vital Signs sensing technologies plus their system architectures and specifications. A focus on Vital Signs acquired by WHDs is made: first a discussion about the most important Vital Signs for health assessment using WHDs is presented and then for each Vital Sign a description is made concerning its origin and effect on heath, monitoring needs, acquisition methods and WHDs and recent scientific developments on the area (electrocardiogram, heart rate, blood pressure, respiration rate, blood oxygen saturation, blood glucose, skin perspiration, capnography, body temperature, motion evaluation, cardiac implantable devices and ambient parameters). A general WHDs system architecture is presented based on the state-of-the-art. After a global review of WHDs, we zoom in into cardiovascular WHDs, analysing commercial devices and their applicability versus quality, extending this subject to smart t-shirts for medical purposes. Furthermore we present a resumed evolution of these devices based on the prototypes developed along the years. Finally we discuss likely market trends and future challenges for the emerging WHDs area
Cheng-chung Chen - One of the best experts on this subject based on the ideXlab platform.
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Concurrent Vital Sign and Position Sensing of Multiple Individuals Using Self-Injection-Locked Tags and Injection-Locked I/Q Receivers With Arctangent Demodulation
IEEE Transactions on Microwave Theory and Techniques, 2013Co-Authors: Fu-kang Wang, Tzyy-sheng Horng, Kang-chun Peng, Jian-yu Li, Chia-hui Fang, Cheng-chung ChenAbstract:This work presents a wireless system that operates in the 2.4 GHz ISM band for concurrently sensing the Vital Signs and positions of multiple individuals. Characterized by low complexity and high accuracy, the proposed system consists of two main parts. One is a self-injection-locked (SIL) tag carried by a subject, which emits a sinusoidal frequency-modulated (SFM) Signal with Vital Sign information. The other is a group of injection-locked (IL) I/Q receivers, which performs arctangent demodulation of the SFM Signal to obtain the position information without using RF reference Signals, and simultaneously extracts the Vital Sign information of the subject. In the experiment, the system is capable of sensing multiple individuals based on frequency division multiple access (FDMA) technique. Moreover, fidgeting effect on the detection of Vital Signs has been greatly reduced by a spectral product approach. Accordingly, it is demonstrated that the experimental prototype provides accurate information about the Vital Signs and positions of different individuals in an indoor environment.
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A Novel Vital-Sign Sensor Based on a Self-Injection-Locked Oscillator
IEEE Transactions on Microwave Theory and Techniques, 2010Co-Authors: Fu-kang Wang, Chien-jung Li, Tzyy-sheng Horng, Chieh-hsun Hsiao, Kang-chun Peng, Jian-yu Li, Cheng-chung ChenAbstract:A novel Vital-Sign sensor with a self-injection-locked oscillator and a frequency demodulator to reduce system complexity and improve sensitivity is proposed. The theory provides a delta-sigma model to account for the excellent Signal-to-noise spectral density ratio in a parametric study of the sensitivity performance. Then, the experiments verify the sensing principle and the predicted performance. Accordingly, a prototype sensor with high sensitivity is realized for noncontact cardiopulmonary monitoring, achieving a long sensing distance without the need for a low-noise amplifier. The sensing distance can grow four times longer by doubling the operating frequency. Furthermore, the sensor using a swept frequency can eliminate the null detection points and the external radio interference. As an experimental result, the sensor, which is placed 4 m away from the subject, can reliably detect the heartbeat Signal an the operating frequency of 3.6 GHz and an output power level of 0 dBm.
Jonggwan Yook - One of the best experts on this subject based on the ideXlab platform.
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Sensitivity Enhanced Vital Sign Detection Based on Antenna Reflection Coefficient Variation
IEEE Transactions on Biomedical Circuits and Systems, 2015Co-Authors: Yong-jun An, Jonggwan YookAbstract:This paper presents a Vital Sign detection sensor based on reflection coefficient variance from an antenna used in wireless communication devices. The near-field effect is estimated by performing 3D full-wave simulations using a dipole antenna and the magnitude variation of the reflection coefficient induced by human thorax movement due to heart and lungs is observed. The results support the possibility of Vital Sign detection based on the magnitude variation of the reflection coefficient from an antenna, which can be explained as a narrowband modulation scheme. In particular, a sensitivity enhancement method is proposed and analyzed, and experiments are carried out for heartbeat detection using a dipole antenna with the proposed system. Experimental results are compared between the direct detection and sensitivity enhancement detection schemes. FM Signal is also applied to confirm that the proposed sensor works properly in conjunction with an existing communication system. The proposed cardiopulmonary detection sensor is implemented with off-the-shelf components at 2.4 GHz and excellent performance is obtained.
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noncontact proximity Vital Sign sensor based on pll for sensitivity enhancement
IEEE Transactions on Biomedical Circuits and Systems, 2014Co-Authors: Yunseog Hong, Sung Jae Ha, Jonggwan YookAbstract:: In this paper, a noncontact proximity Vital Sign sensor, using a phase locked loop (PLL) incorporated with voltage controlled oscillator (VCO) built-in planar type circular resonator, is proposed to enhance sensitivity in severe environments. The planar type circular resonator acts as a series feedback element of the VCO as well as a near-field receiving antenna. The frequency deviation of the VCO related to the body proximity effect ranges from 0.07 MHz/mm to 1.8 MHz/mm (6.8 mV/mm to 205 mV/mm in sensitivity) up to a distance of 50 mm, while the amount of VCO drift is about 21 MHz in the condition of 60 (°)C temperature range and discrete component tolerance of ± 5%. Total frequency variation occurs in the capture range of the PLL which is 60 MHz. Thus, its loop control voltage converts the amount of frequency deviation into a difference of direct current (DC) voltage, which is utilized to extract Vital Signs regardless of the ambient temperature. The experimental results reveal that the proposed sensor placed 50 mm away from a subject can reliably detect respiration and heartbeat Signals without the ambiguity of harmonic Signals caused by respiration Signal at an operating frequency of 2.4 GHz.
Duarte Dias - One of the best experts on this subject based on the ideXlab platform.
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wearable health devices Vital Sign monitoring systems and technologies
Sensors, 2018Co-Authors: Duarte Dias, João Paulo Silva CunhaAbstract:Wearable Health Devices (WHDs) are increasingly helping people to better monitor their health status both at an activity/fitness level for self-health tracking and at a medical level providing more data to clinicians with a potential for earlier diagnostic and guidance of treatment. The technology revolution in the miniaturization of electronic devices is enabling to deSign more reliable and adaptable wearables, contributing for a world-wide change in the health monitoring approach. In this paper we review important aspects in the WHDs area, listing the state-of-the-art of wearable Vital Signs sensing technologies plus their system architectures and specifications. A focus on Vital Signs acquired by WHDs is made: first a discussion about the most important Vital Signs for health assessment using WHDs is presented and then for each Vital Sign a description is made concerning its origin and effect on heath, monitoring needs, acquisition methods and WHDs and recent scientific developments on the area (electrocardiogram, heart rate, blood pressure, respiration rate, blood oxygen saturation, blood glucose, skin perspiration, capnography, body temperature, motion evaluation, cardiac implantable devices and ambient parameters). A general WHDs system architecture is presented based on the state-of-the-art. After a global review of WHDs, we zoom in into cardiovascular WHDs, analysing commercial devices and their applicability versus quality, extending this subject to smart t-shirts for medical purposes. Furthermore we present a resumed evolution of these devices based on the prototypes developed along the years. Finally we discuss likely market trends and future challenges for the emerging WHDs area.
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Wearable Health Devices—Vital Sign Monitoring, Systems and Technologies
MDPI AG, 2018Co-Authors: Duarte Dias, João Paulo Silva CunhaAbstract:Wearable Health Devices (WHDs) are increasingly helping people to better monitor their health status both at an activity/fitness level for self-health tracking and at a medical level providing more data to clinicians with a potential for earlier diagnostic and guidance of treatment. The technology revolution in the miniaturization of electronic devices is enabling to deSign more reliable and adaptable wearables, contributing for a world-wide change in the health monitoring approach. In this paper we review important aspects in the WHDs area, listing the state-of-the-art of wearable Vital Signs sensing technologies plus their system architectures and specifications. A focus on Vital Signs acquired by WHDs is made: first a discussion about the most important Vital Signs for health assessment using WHDs is presented and then for each Vital Sign a description is made concerning its origin and effect on heath, monitoring needs, acquisition methods and WHDs and recent scientific developments on the area (electrocardiogram, heart rate, blood pressure, respiration rate, blood oxygen saturation, blood glucose, skin perspiration, capnography, body temperature, motion evaluation, cardiac implantable devices and ambient parameters). A general WHDs system architecture is presented based on the state-of-the-art. After a global review of WHDs, we zoom in into cardiovascular WHDs, analysing commercial devices and their applicability versus quality, extending this subject to smart t-shirts for medical purposes. Furthermore we present a resumed evolution of these devices based on the prototypes developed along the years. Finally we discuss likely market trends and future challenges for the emerging WHDs area
