scholarly journals MW-PPG Sensor: An on-Chip Spectrometer Approach

Sensors ◽  
2019 ◽  
Vol 19 (17) ◽  
pp. 3698 ◽  
Author(s):  
Cheng-Chun Chang ◽  
Chien-Ta Wu ◽  
Byung Il Choi ◽  
Tong-Jing Fang
Keyword(s):  
Blood Pressure ◽  
Daily Life ◽  
Signal To Noise Ratio ◽  
Blood Oxygen ◽  
Signal To Noise ◽  
Signal Wavelength ◽  
Sensing Technology ◽  
Multi Wavelength ◽  
On Chip ◽  
Signal Processing Methods

Multi-wavelength photoplethysmography (MW-PPG) sensing technology has been known to be superior to signal-wavelength photoplethysmography (SW-PPG) sensing technology. However, limited by the availability of sensing detectors, many prior studies can only use conventional bulky and pricy spectrometers as the detectors, and hence cannot bring the MW-PPG technology to daily-life applications. In this study we developed a chip-scale MW-PPG sensor using innovative on-chip spectrometers, aimed at wearable applications. Also in this paper we present signal processing methods for robustly extracting the PPG signals, in which an increase of up to 50% in the signal-to-noise ratio (S/N) was observed. Example measurements of saturation of peripheral blood oxygen (SpO2) and blood pressure were conducted.

3 T: the good, the bad and the ugly

2021 ◽  
Author(s):  
Martin John Graves
Keyword(s):  
Signal To Noise Ratio ◽  
Relaxation Times ◽  
Blood Oxygen Level Dependent ◽  
Blood Oxygen ◽  
Rf Power ◽  
Blood Oxygen Level ◽  
Signal To Noise ◽  
Improve Image Quality ◽  
Mr Physics ◽  
T System

It is around 20 years since the first commercial 3 T MRI systems became available. The theoretical promise of twice the signal-to-noise ratio of a 1.5 T system together with a greater sensitivity to magnetic susceptibility-related contrast mechanisms, such as the blood oxygen level dependent (BOLD) effect that is the basis for functional MRI (fMRI), drove the initial market in neuroradiology. However, the limitations of the increased field strength soon became apparent, including the increased radiofrequency (RF) power deposition, tissue dependent changes in relaxation times, increased artifacts, and greater safety concerns. Many of these issues are dependent upon MR physics and work arounds have had to be developed to try and mitigate their effects. This article reviews the underlying principles of the good, the bad and the ugly aspects of 3 T, discusses some of the methods used to improve image quality and explains the remaining challenges and concerns.

Development of All Time Multi-Wavelength Lidar System and Analysis of Its Signal to Noise Ratio

2015 ◽  
Vol 42 (1) ◽  
pp. 0113001
Author(s):  
赵虎 Zhao Hu ◽  
华灯鑫 Hua Dengxin ◽  
狄慧鸽 Di Huige ◽  
侯晓龙 Hou Xiaolong ◽  
阎蕾洁 Yan Leijie ◽  
...  
Keyword(s):  
Signal To Noise Ratio ◽  
Signal To Noise ◽  
Lidar System ◽  
Multi Wavelength ◽  
Noise Ratio

Engulfment of Protruding Micro-Nails Fabricated on Chip Surface by Cultured Neurons Improve Their Adhesion to The Electronic Device

2007 ◽  
Vol 1004 ◽  
Author(s):  
Micha E. Spira ◽  
Dotan Kamber ◽  
Ada Dormann ◽  
Ariel Cohen ◽  
Carmen Bartic ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Electrical Resistance ◽  
Electronic Device ◽  
Signal To Noise Ratio ◽  
Electrical Coupling ◽  
Physical Contact ◽  
Cultured Neurons ◽  
Signal To Noise ◽  
Chip Surface ◽  
On Chip

AbstractOne of the major problems in assembling efficient neuro-electronic hybrids systems is the low electrical coupling between the components. This is mainly due to the low resistance, extracellular cleft formed between the cell's plasma membrane and the substrate to which it adhere. This cleft shunts the current generated by the neuron, or the device and thus reduces the signal to noise ratio. To increase the clefts electrical resistance we fabricated gold micronails that protrude from the transistor gate surface. The micronails were functionalized by phagocytosis facilitating peptides. Cultured neurons readily engulf the functionalized micronails forming tight physical contact between the cells and the surface of the device

(Invited) InGaP Photodiode with 50% Increased EQE and Higher Signal to Noise Ratio for Blood Pressure Measurement

2018 ◽  
Vol 85 (9) ◽  
pp. 87-91
Author(s):  
Yung-Hua Kao ◽  
Chang-Po Chao ◽  
Amarendra Kumar ◽  
Yi-Chieh Lin ◽  
Chia-Liang Hsu
Keyword(s):  
Blood Pressure ◽  
Pressure Measurement ◽  
Signal To Noise Ratio ◽  
Blood Pressure Measurement ◽  
Signal To Noise ◽  
Noise Ratio

A Case Study of Signal-to-Noise Ratio in Ring-Based Optical Networks-on-Chip

2014 ◽  
Vol 31 (5) ◽  
pp. 55-65 ◽  
Author(s):  
Luan H. K. Duong ◽  
Mahdi Nikdast ◽  
Sebastien Le Beux ◽  
Jiang Xu ◽  
Xiaowen Wu ◽  
...  
Keyword(s):  
Optical Networks ◽  
Signal To Noise Ratio ◽  
Signal To Noise ◽  
Networks On Chip ◽  
Noise Ratio ◽  
On Chip

A tunable multi-wavelength Brillouin-erbium linear cavity fiber laser with higher optical signal to noise ratio

Laser Physics ◽  
2018 ◽  
Vol 28 (12) ◽  
pp. 125105
Author(s):  
Lei Ma ◽  
Hui Zou ◽  
Hui Xiong ◽  
Guanhong You ◽  
Yunshan Zhang ◽  
...  
Keyword(s):  
Fiber Laser ◽  
Signal To Noise Ratio ◽  
Optical Signal ◽  
Signal To Noise ◽  
Linear Cavity ◽  
Multi Wavelength ◽  
Noise Ratio

Correlation of Brillouin Stokes Signals and Optical-Signal-to-Noise-Ratio in Multi-Wavelength Brillouin Fiber Laser with Additional Fiber Bragg Grating

2016 ◽  
Vol 857 ◽  
pp. 560-564 ◽  
Author(s):  
A. Zakiah Malek ◽  
N.A.M. Ahmad Hambali ◽  
M.H.A. Wahid ◽  
M.M. Shahimin ◽  
M.A.M. Azidin
Keyword(s):  
Pump Power ◽  
Fiber Laser ◽  
Fiber Bragg Grating ◽  
Ring Resonator ◽  
Signal To Noise Ratio ◽  
Optical Signal ◽  
Signal To Noise ◽  
Brillouin Pump ◽  
Multi Wavelength ◽  
Noise Ratio

We experimentally demonstrate unidirectional propagation of multi-wavelength Brillouin fiber laser system with additional fiber Bragg grating. The configuration is arranged in a ring resonator by utilizing five different Brillouin gain mediums. In this experiment, the input Brillouin pump power was varied in order to maximize the generated Brillouin Stokes signals based on the respective fiber lengths. The influence of these controllable parameters leads to the correlation between of Brillouin Stokes signals and optical-signal-to-noise-ratio. In this case, at 10 km of single mode fiber the maximum of 38 Brillouin Stokes signals were generated together with 15.07 dB of average optical-signal-to-noise-ratio when the 17 dBm Brillouin pump power was launched into the ring resonator.

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