Sensor factors influencing photoplethysmography

An essential part of efficient herd reproduction management is the prompt insemination of fertile cows after successfully noticing bovine heat. Signs of heat demonstrate that an animal is in estrus, ready to be inseminated. An affordable technique for heat detection is photoplethysmography (PPG, pulse oximetry), which can quantify changes in vulvar blood circulation (swelling and erythema). Previously, only experienced operators applied PPG devices. In this study, an inexperienced user clinically tested PPG for heat detection in nine cows. The analysis focused on the signal baseline (DC component), power, and kurtosis between 0.7 and 3 Hz. Compared to the experienced, inexperienced operator's PPG signal variability significantly increased. The green PPG signal baseline's range (a difference between the 25th and 75th percentile) almost tripled. Furthermore, variability in signal power increased between 6.9 and 13.1 times, indicating several operator-introduced oscillations. The results showed that inexperienced PPG operator retrieves more variable PPG signals than professionals, indicating a need for consistent device handling. The potential changes could include a pressure sensor or a clamp, guaranteeing constant pressure between the PPG sensor and the vaginal wall.

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“…Fourthly, we calculated erythema index (EI) 20 as the ratio between the red (BR) and green baseline (BG):…”

Section: Signal Processingmentioning

confidence: 99%

“…Furthermore, various physiological conditions like regional anesthetic blocks, sepsis, stress, and cold can affect the PPG signal 19 . Finally, PPG signal quality is also impacted by sensor position, motion artifacts, contact force, and bad contact 20 . In our previous study 4 , an experienced PPG operator made all measurements.…”

Section: Introductionmentioning

confidence: 99%

Impact of an inexperienced operator on photoplethysmogram for bovine heat detection

Plavšic¹,

Mavrič²,

Štruc³

et al. 2023

Optical Diagnostics and Sensing XXIII: Toward Point-of-Care Diagnostics

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“…The PPG signal includes essential features based on the original PPG waveform, combined features, and derivative features [ 8 ]. However, the estimation of these attributes is influenced by several factors, which can be classified into three categories: cardiovascular, biological, and acquisition [ 9 , 10 , 11 ]. Acquisition factors are related to the properties and intensity of the emitted light [ 12 ], ambient light [ 13 ], photo-detector sensitivity [ 14 ], measurement point [ 15 ], temperature [ 16 ], motion artifacts [ 17 ], and contact force (CF) between the sensor and the skin [ 18 ], among others.…”

Section: Introductionmentioning

confidence: 99%

Novel Multi-Parametric Sensor System for Comprehensive Multi-Wavelength Photoplethysmography Characterization

Cause

Morillo

Silva

et al. 2023

Sensors

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Photoplethysmography (PPG) is widely used to assess cardiovascular health. However, its usage and standardization are limited by the impact of variable contact force and temperature, which influence the accuracy and reliability of the measurements. Although some studies have evaluated the impact of these phenomena on signal amplitude, there is still a lack of knowledge about how these perturbations can distort the signal morphology, especially for multi-wavelength PPG (MW-PPG) measurements. This work presents a modular multi-parametric sensor system that integrates continuous and real-time acquisition of MW-PPG, contact force, and temperature signals. The implemented design solution allows for a comprehensive characterization of the effects of the variations in these phenomena on the contour of the MW-PPG signal. Furthermore, a dynamic DC cancellation circuitry was implemented to improve measurement resolution and obtain high-quality raw multi-parametric data. The accuracy of the MW-PPG signal acquisition was assessed using a synthesized reference PPG optical signal. The performance of the contact force and temperature sensors was evaluated as well. To determine the overall quality of the multi-parametric measurement, an in vivo measurement on the index finger of a volunteer was performed. The results indicate a high precision and accuracy in the measurements, wherein the capacity of the system to obtain high-resolution and low-distortion MW-PPG signals is highlighted. These findings will contribute to developing new signal-processing approaches, advancing the accuracy and robustness of PPG-based systems, and bridging existing gaps in the literature.

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Effects of Measurement Site on Heart Rate Variability Derived from Photoplethysmography

Sarkar

Pahuja

2022

ICT Systems and Sustainability

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Sensor factors influencing photoplethysmography

Cited by 6 publications

References 11 publications

Impact of an inexperienced operator on photoplethysmogram for bovine heat detection

Impact of an inexperienced operator on photoplethysmogram for bovine heat detection

Novel Multi-Parametric Sensor System for Comprehensive Multi-Wavelength Photoplethysmography Characterization

Effects of Measurement Site on Heart Rate Variability Derived from Photoplethysmography

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