Ambiguity of mapping the relative phase of blood pulsations

Teplov, Victor; Nippolainen, Ervin; Makarenko, Alexander A.; Giniatullin, Rashid; Kamshilin, Alexei A.

doi:10.1364/boe.5.003123

Cited by 25 publications

(25 citation statements)

References 27 publications

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“…We used a custom iPPG system to collect the data from the palm area of a subject. The system was described in detail by Teplov et al [21]. In summary, we used two conventional lightemitting diodes (LED) operating at a wavelength of 525 nm (green light) to illuminate the subject's palm.…”

Section: Instrumentationmentioning

confidence: 99%

Influence of a skin status on the light interaction with dermis

Kamshilin¹,

Mamontov²,

Koval³

et al. 2015

Biomed. Opt. Express

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We present experimental evidence that the parameters of green light remitted from a human tissue in-vivo strongly depend on skin contact status. In case when the skin is free of any contact, simultaneous recording of imaging photoplethysmogram (iPPG) and electrocardiogram revealed that contactless iPPG fails in correct estimates of the heart rate in almost half of the cases. Meanwhile, the number of successful correlations between ECG and iPPG is significantly increased when the skin is in contact with a glass plate. These observations are in line with the recently proposed model in which pulsatile arteries deform the connective-tissue components of the dermis thus resulting in temporal modulation of the capillary density interacting with slightly penetrating light.

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Section: Instrumentationmentioning

confidence: 99%

Influence of a skin status on the light interaction with dermis

Kamshilin¹,

Mamontov²,

Koval³

et al. 2015

Biomed. Opt. Express

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“…At the first step of the algorithm, we calculated the spatial distribution of the blood pulsations amplitude (BPA) by using synchronous amplification of the recorded frames with the heartbeat frequency, which was described in details in our previous papers [21,28]. Briefly, the technique includes the following steps.…”

Section: Data Processingmentioning

confidence: 99%

“…(A) Finding the beginning and duration of each cardiac cycle from frame-to-frame evolution of the mean pixel value in a region of 11 × 11 pixels (2.5 × 2.5 mm 2 ) situated in the distal phalanx of the long finger. (B) Using these data for defining the complex reference function of the sinusoidal type for every cardiac cycle, which is required for lock-in amplification [28]. (C) Calculating a correlation matrix between each pixel intensity in the frame and the reference function for each cardiac cycle.…”

Section: Data Processingmentioning

confidence: 99%

“…(C) Calculating a correlation matrix between each pixel intensity in the frame and the reference function for each cardiac cycle. The modulus of the correlation matrix represents the spatial distribution of BPA as the AC/DC ratio measured in percent [28]. The set of correlation matrices calculated for each cardiac cycle shows BPA evolution in time and space.…”

Section: Data Processingmentioning

confidence: 99%

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Local Thermal Impact on Microcirculation Assessed by Imaging Photoplethysmography

Kamshilin¹,

Belaventseva²,

Romashko³

et al. 2016

Biol Med (Aligarh)

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Laser Doppler Flowmetry and Laser Speckle Contrast Imaging are applied usually for assessment of parameters of the cutaneous blood flow during thermoregulation. Alternatively, this work explores the feasibility of blood pulsation imaging under incoherent green illumination for measuring the response of human body on local thermal impact. The proposed technique allows assessment of the cutaneous blood flow changes during thermoregulation simultaneously in different areas of the body. The preliminary experiments show that the blood pulsation amplitude (BPA) is sufficiently reliable index, which could characterize the relative change of the cutaneous blood flow similarly to the parameter measured with the Laser Doppler Flowmetry technique. It is shown that BPA grows up proportionally to the skin temperature increase in the preliminary cooled finger, whilst it is in the steady state in another finger having the constant temperature. The rate of BPA increase is individual characteristic of a subject, which could serve as a parameter of the subject's vasomotor reactivity on the temperature changes. High quality of visualized distribution of blood pulsations, good repeatability of the BPA, and revealed dependencies of its response on the skin-temperature change offer the prospect for development new system of studying microcirculation.

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“…By using the BPI technique, it was recently shown [Kamshilin (2013)] that the amplitude of blood pulsations is unevenly distributed over the observed area forming clearly visible hot spots in which the amplitude of blood pulsations is higher than in other areas. Position of these hot spots is specific for each individual [Kamshilin (2013), Teplov (2014)]. However, no experimental study of the amplitude of blood pulsations in these spots has been carried out.…”

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confidence: 99%