Low-frequency photoplethysmograph signals

Harness, J.B.; Marjanovic, D

doi:10.1088/0143-0815/10/4/009

Cited by 7 publications

(3 citation statements)

References 5 publications

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“…This AC component is superimposed onto a large quasi-DC component that relates to the tissues and to the average blood volume. This DC component varies slowly due to respiration, vasomotor activity and vasoconstrictor waves, Traube Hering Mayer (THM) waves and also thermoregulation (Burton 1939, Burton and Taylor 1940, Hertzman and Dillon 1940b, Hertzman and Roth 1942a, 1942b, 1942c, Hertzman and Flath 1963, Hyndman et al 1971, Peñáz 1978, Ahmed et al 1982, Harness and Marjanovic 1989, Nitzan et al 1996b, 1996a, general thermoregulatory pulse changes in Shusterman et al (1997), Schultz-Ehrenburg and Blazek (2001), Nitzan et al (2001)). These characteristics are also body site dependent (Allen and Murray 2000b).…”

Section: The Photoplethysmography Waveformmentioning

confidence: 99%

Photoplethysmography and its application in clinical physiological measurement

2007

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Photoplethysmography (PPG) is a simple and low-cost optical technique that can be used to detect blood volume changes in the microvascular bed of tissue. It is often used non-invasively to make measurements at the skin surface. The PPG waveform comprises a pulsatile ('AC') physiological waveform attributed to cardiac synchronous changes in the blood volume with each heart beat, and is superimposed on a slowly varying ('DC') baseline with various lower frequency components attributed to respiration, sympathetic nervous system activity and thermoregulation. Although the origins of the components of the PPG signal are not fully understood, it is generally accepted that they can provide valuable information about the cardiovascular system. There has been a resurgence of interest in the technique in recent years, driven by the demand for low cost, simple and portable technology for the primary care and community based clinical settings, the wide availability of low cost and small semiconductor components, and the advancement of computer-based pulse wave analysis techniques. The PPG technology has been used in a wide range of commercially available medical devices for measuring oxygen saturation, blood pressure and cardiac output, assessing autonomic function and also detecting peripheral vascular disease. The introductory sections of the topical review describe the basic principle of operation and interaction of light with tissue, early and recent history of PPG, instrumentation, measurement protocol, and pulse wave analysis. The review then focuses on the applications of PPG in clinical physiological measurements, including clinical physiological monitoring, vascular assessment and autonomic function.

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Section: The Photoplethysmography Waveformmentioning

confidence: 99%

Photoplethysmography and its application in clinical physiological measurement

2007

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“…Now that the channels are separated by the S/H, it is possible to filter the signal to remove unnecessary components, typically noise. Common cutoff frequencies present in literature range from 8 to 30 Hz [63][64][65][66][67][68]. After analysing the PPG signal and testing some different frequencies, 20 Hz was chosen as a good value for cutoff frequency.…”

Section: Signal Conditioningmentioning

confidence: 99%

Photoplethysmographic logger with contact force and hydrostatic pressure monitoring

Santos

Almeida

Cardoso

et al. 2013

2013 IEEE 3rd Portuguese Meeting in Bioengineering (ENBENG)

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Esta cópia da tese é fornecida na condição de que quem a consulta reconhece que os direitos de autor são pertença da Universidade de Coimbra e que nenhuma citação ou informação obtida a partir dela pode ser publicada sem a referência apropriada.This copy of the thesis has been supplied on condition that anyone who consults it is understood to recognize that its copyright rests with University of Coimbra and that no quotation from the thesis and no information derived from it may be published without proper acknowledgement. This work is funded by FEDER, through the Programa Operacional Factores deCompetitividade -COMPETE -and by National funds through FCT -Fundação para a Ciência e Tecnologia -in the frame of -Centro Aos companheiros Gonçalo Costa, Hugo Ramalho e Tiago Leal, que ao meu lado deram incontáveis braçadas (eu mais do que eles!) dentro e fora da piscina, um agradecimento particular. Uma palavra de apreço também para o amigo de infância, Ricardo Pimentel, pelos muitos momentos partilhados ao longo de todo este tempo.Ainda um brinde em honra de quem nestes anos me acompanhou: Carla Guerra, Carolina Francisco, Gabriel Campos, Mariana Sequeira e Susete Neiva. The current work aims to develop a stand-alone pulse oximeter and a photoplethysmographic (PPG) system with measurements of the contact force and height of the finger relatively to the heart. This module, together with other measurements (e.g.electrocardiogram and pulse wave velocity), will be part of a multichannel platform that will be taken to clinical environment.The project comprises the design of hardware for signal conditioning, as well as the development of firmware to implement in a microcontroller unit (the Arduino™). The latter is used to control the system, acquire data and compute , heart rate ( ), contact force and height.Currently, the system is able to retrieve a stable PPG waveform and compute the in real time through the PPG signal peaks and valleys. Signals acquired in a healthy subject lead to a value of . Moreover, the subject arm and forearm orientation is retrieved by the use of accelerometers and used to compute the offset of the finger relatively to the heart. Contact force between the finger and the probe is also measured. Keywords

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“…Clinical PPG applications range from monitoring of blood pressure, heart and respiration rate, blood oxygen saturation, to detection of peripheral vascular diseases. The technique functions by illuminating skin with penetrating optical radiation usually from a light emitting diode and detecting the transmitted signal in the case of transmission mode PPG, where the photodetector is positioned directly across from the light source, or the reflected signal, for the case of reflection mode PPG achieved by locating the photodetector next to the light source (Harness andMarjanovic 1989, Stojanovic andKaradaglic 2007). The modified Beer-Lambert law suffices in explaining the origin of the PPG waveform (Shelley 2007).…”

Section: Introductionmentioning

confidence: 99%

Investigating a smartphone imaging unit for photoplethysmography

Jonathan¹,

Leahy²

2010

Physiol. Meas.

165

105

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Current-generation smartphones boast a video unit comprising a camera next to a white light emitting diode and this configuration would be suitable for reflection-mode bio-optical sensing and imaging applications. We demonstrate reflection photoplethysmographic (PPG) imaging using this technology on the index finger of a male volunteer during rest and immediately after performing a short run. The returned signals carry useful PPG signals and were used, for example, to compute change in heart rate. Our results are encouraging, especially in the area of personal and home-based care applications.

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Low-frequency photoplethysmograph signals

Cited by 7 publications

References 5 publications

Photoplethysmography and its application in clinical physiological measurement

Photoplethysmography and its application in clinical physiological measurement

Photoplethysmographic logger with contact force and hydrostatic pressure monitoring

Investigating a smartphone imaging unit for photoplethysmography

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