Search results for "Plethysmograph"
showing 10 items of 94 documents
Low invasive multisensor acquisition system for real-time monitoring of cardiovascular and respiratory parameters
2020
The recent advances in multiparametric monitoring of biosignals and management of big data prompt for the development of devices and techniques for the extraction of indicators with physiological relevance. In this context, we have designed and realized a portable electronic system, equipped with simple biomedical sensors, able to synchronously record multiple electrocardiographic (ECG), photoplethysmographic (PPG) and breathing signals, for carrying out a non-invasive monitoring of several cardiovascular parameters. In this work, we show the results of preliminary measurements performed following a specific physiological protocol (i.e., deep breathing with 10 s per cycle). The system allow…
Transthoracic electrical impedance during extracorporeal hemodialysis in acute respiratory failure ("Shocked Lung syndrome").
1980
The alteration (delta Z0) of transthoracic electrical impedance (TEI) during extracorporeal hemodialysis (EHD) was investigated in two Groups of patients with acute renal and acute respiratory failure, that differed with respect to the severity of respiratory insufficiency. Group I had moderate respiratory failure (FiO2 0.31 +/- 0.10, PaO2 84 +/- 14 mmHg), and Group II had severe respiratory failure (FiO2 0.75 +/- 0.17, PaO2 77 +/- 14 mmHg). There was a significant correlation between increase in TEI (delta Z0) and decrease in body weight (delta BW) in each individual patient, but the slope of regression lines was remarkably flattened in Group II. In Group I, delta TEI was 1.9 +/- 0.9 omega…
A portable electronic system for non-invasive real-time acquisition of multiple physiological signals
2019
In this work, we have designed and realised a portable and compact electronic system for the synchronous acquisition of multiple physiological signals. The system employs a Texas Instruments ADS1298 front-end with 24-bit resolution for data acquisition and supports up to 8 channels and 4 kHz sampling rate. The front-end communicates via SPI with a STM32 microcontroller which pre-processes the data and sends them through USB or Bluetooth to a suitable PC application. The system has been realized for the simultaneous acquisition of electrocardiographic (ECG) and photoplethysmographic (PPG) signals, but it can also be employed for acquiring other typologies of signals, e.g. breathing or electr…
Video-Based Heartbeat Rate Measuring Method Using Ballistocardiography
2017
International audience; Video-based heartbeat rate measurement is a rapidly growing application in remote health monitoring. Video-based heartbeat rate measuring methods operate mainly by estimating photoplethysmography or ballistocardiography signals. These methods operate by estimating the microscopic color change in the face or by estimating the microscopic rigid motion of the head/facial skin. However, the robustness to motion artifacts caused by illumination variance and motion variance of the subject poses main challenge. We present a video-based heartbeat rate measuring framework to overcome these problems by using the principle of ballistocardiography. In this paper, we proposed a b…
Effect of Motion Artifact on Digital Camera Based Heart Rate Measurement
2017
International audience; Depression is one of the most prevalent mental disorders, burdening many people world-wide. A system with the potential of serving as a decision support system is proposed, based on novel features extracted from facial expression geometry and speech, by interpreting non-verbal manifestations of depression. The proposed system has been tested both in gender independent and gender based modes, and with different fusion methods. The algorithms were evaluated for several combinations of parameters and classification schemes, on the dataset provided by the Audio/Visual Emotion Challenge of 2013 and 2014. The proposed framework achieved a precision of 94.8% for detecting p…
Photoplethysmography for bovine heat detection: the preliminary results
2020
In this study, we applied photoplethysmography (PPG) as an alternative, convenient, and affordable method for bovine heat detection. Heat detection is an essential part of effective herd reproduction management. Currently, there are many different heat detection techniques, but they can be ineffective or impractical to use. Since heat affects local vulvar blood circulation (resulting in swelling and erythema), photoplethysmography could represent an affordable alternative to detect this bovine phenomenon. In this study, we enrolled 20 animals in heat and other stages of the bovine reproduction cycle. We analyzed the PPG signal in terms of baseline (DC component), power, kurtosis, and erythe…
A study on the effect of contact pressure during physical activity on photoplethysmographic heart rate measurements
2020
Heart rate (HR) as an important physiological indicator could properly describe global subject&rsquo
Comparison of region of interest segmentation methods for video-based heart rate measurements
2018
International audience; Conventional contact photoplethysmography (PPG) sensors are not suitable in situations of skin damage or when unconstrained movement is required. As a consequence, remote photoplethysmography (rPPG) has recently emerged because it provides remote physiological measurements without expensive hardware and improves comfort for long-term monitoring. RPPG estimation methods use the spatially averaged RGB values of pixels in a Region Of Interest (ROI) to generate a temporal RGB signal. The selection of ROI is a critical first step to obtain reliable pulse signals and must contain as many skin pixels as possible with a low percentage of non-skin pixels. In this paper, we ex…
Remote Photoplethysmography for Evaluation of Cutaneous Sensory Nerve Fiber Function
2021
About 2% of the world’s population suffers from small nerve fiber dysfunction, neuropathy, which can result in severe pain. This condition is caused by damage to the small nerve fibers and its assessment is challenging, due to the lack of simple and objective diagnostic techniques. The present study aimed to develop a contactless photoplethysmography system using simple instrumentation, for objective and non-invasive assessment of small cutaneous sensory nerve fiber function. The approach is based on the use of contactless photoplethysmography for the characterization of skin flowmotions and topical heating evoked vasomotor responses. The feasibility of the technique was evaluated on volunt…
The analysis of blood flow changes under local anesthetic input using non-contact technique
2010
In this work photoplethysmography imaging (PPGI) technique was used to obtain blood flow changes in human skin under regional anesthesia (RA). PPGI was evaluated from video taken by video camera for 26 patients 2 minutes before and immediately after RA, using custom developed software. Results showed that blood flow obtained by PPGI increases immediately after RA effect and the amplitude of PPGI showed correlation with temperature changes in human skin (r=0.8±0.14, p<0.0001). We found that PPGI technique can be usable for non-contact monitoring of quality of RA.