A Comparative Evaluation of Heart Rate Estimation Methods using Face Videos

This paper presents a comparative evaluation of methods for remote heart rate estimation using face videos, i.e., given a video sequence of the face as input, methods to process it to obtain a robust estimation of the subjects heart rate at each moment. Four alternatives from the literature are tested, three based in hand crafted approaches and one based on deep learning. The methods are compared using RGB videos from the COHFACE database. Experiments show that the learning-based method achieves much better accuracy than the hand crafted ones. The low error rate achieved by the learning based model makes possible its application in real scenarios, e.g. in medical or sports environments.Comment: Accepted in "IEEE International Workshop on Medical Computing (MediComp) 2020

DistancePPG: Robust non-contact vital signs monitoring using a camera

Vital signs such as pulse rate and breathing rate are currently measured using contact probes. But, non-contact methods for measuring vital signs are desirable both in hospital settings (e.g. in NICU) and for ubiquitous in-situ health tracking (e.g. on mobile phone and computers with webcams). Recently, camera-based non-contact vital sign monitoring have been shown to be feasible. However, camera-based vital sign monitoring is challenging for people with darker skin tone, under low lighting conditions, and/or during movement of an individual in front of the camera. In this paper, we propose distancePPG, a new camera-based vital sign estimation algorithm which addresses these challenges. DistancePPG proposes a new method of combining skin-color change signals from different tracked regions of the face using a weighted average, where the weights depend on the blood perfusion and incident light intensity in the region, to improve the signal-to-noise ratio (SNR) of camera-based estimate. One of our key contributions is a new automatic method for determining the weights based only on the video recording of the subject. The gains in SNR of camera-based PPG estimated using distancePPG translate into reduction of the error in vital sign estimation, and thus expand the scope of camera-based vital sign monitoring to potentially challenging scenarios. Further, a dataset will be released, comprising of synchronized video recordings of face and pulse oximeter based ground truth recordings from the earlobe for people with different skin tones, under different lighting conditions and for various motion scenarios.Comment: 24 pages, 11 figure

Neonatal non-contact respiratory monitoring based on real-time infrared thermography

<p>Abstract</p> <p>Background</p> <p>Monitoring of vital parameters is an important topic in neonatal daily care. Progress in computational intelligence and medical sensors has facilitated the development of smart bedside monitors that can integrate multiple parameters into a single monitoring system. This paper describes non-contact monitoring of neonatal vital signals based on infrared thermography as a new biomedical engineering application. One signal of clinical interest is the spontaneous respiration rate of the neonate. It will be shown that the respiration rate of neonates can be monitored based on analysis of the anterior naris (nostrils) temperature profile associated with the inspiration and expiration phases successively.</p> <p>Objective</p> <p>The aim of this study is to develop and investigate a new non-contact respiration monitoring modality for neonatal intensive care unit (NICU) using infrared thermography imaging. This development includes subsequent image processing (region of interest (ROI) detection) and optimization. Moreover, it includes further optimization of this non-contact respiration monitoring to be considered as physiological measurement inside NICU wards.</p> <p>Results</p> <p>Continuous wavelet transformation based on Debauches wavelet function was applied to detect the breathing signal within an image stream. Respiration was successfully monitored based on a 0.3°C to 0.5°C temperature difference between the inspiration and expiration phases.</p> <p>Conclusions</p> <p>Although this method has been applied to adults before, this is the first time it was used in a newborn infant population inside the neonatal intensive care unit (NICU). The promising results suggest to include this technology into advanced NICU monitors.</p

Adaptive Movement Compensation for In Vivo Imaging of Fast Cellular Dynamics within a Moving Tissue

In vivo non-linear optical microscopy has been essential to advance our knowledge of how intact biological systems work. It has been particularly enabling to decipher fast spatiotemporal cellular dynamics in neural networks. The power of the technique stems from its optical sectioning capability that in turn also limits its application to essentially immobile tissue. Only tissue not affected by movement or in which movement can be physically constrained can be imaged fast enough to conduct functional studies at high temporal resolution. Here, we show dynamic two-photon Ca2+ imaging in the spinal cord of a living rat at millisecond time scale, free of motion artifacts using an optical stabilization system. We describe a fast, non-contact adaptive movement compensation approach, applicable to rough and weakly reflective surfaces, allowing real-time functional imaging from intrinsically moving tissue in live animals. The strategy involves enslaving the position of the microscope objective to that of the tissue surface in real-time through optical monitoring and a closed feedback loop. The performance of the system allows for efficient image locking even in conditions of random or irregular movements

In-Suit Doppler Technology Assessment

The objective of this program was to perform a technology assessment survey of non-invasive air embolism detection utilizing Doppler ultrasound methodologies. The primary application of this technology will be a continuous monitor for astronauts while performing extravehicular activities (EVA's). The technology assessment was to include: (1) development of a full understanding of all relevant background research; and (2) a survey of the medical ultrasound marketplace for expertise, information, and technical capability relevant to this development. Upon completion of the assessment, LSR was to provide an overview of technological approaches and R&D/manufacturing organizations

Catatonia during deep brain stimulator implantation complicated by intracranial hemorrhage

No abstract.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/77450/1/23041_ftp.pd

Video pulse rate variability analysis in stationary and motion conditions

Background: In the last few years, some studies have measured heart rate (HR) or heart rate variability (HRV) parameters using a video camera. This technique focuses on the measurement of the small changes in skin colour caused by blood perfusion. To date, most of these works have obtained HRV parameters in stationary conditions, and there are practically no studies that obtain these parameters in motion scenarios and by conducting an in-depth statistical analysis. Methods: In this study, a video pulse rate variability (PRV) analysis is conducted by measuring the pulse-to-pulse (PP) intervals in stationary and motion conditions. Firstly, given the importance of the sampling rate in a PRV analysis and the low frame rate of commercial cameras, we carried out an analysis of two models to evaluate their performance in the measurements. We propose a selective tracking method using the Viola–Jones and KLT algorithms, with the aim of carrying out a robust video PRV analysis in stationary and motion conditions. Data and results of the proposed method are contrasted with those reported in the state of the art. Results: The webcam achieved better results in the performance analysis of video cameras. In stationary conditions, high correlation values were obtained in PRV parameters with results above 0.9. The PP time series achieved an RMSE (mean ± standard deviation) of 19.45 ± 5.52 ms (1.70 ± 0.75 bpm). In the motion analysis, most of the PRV parameters also achieved good correlation results, but with lower values as regards stationary conditions. The PP time series presented an RMSE of 21.56 ± 6.41 ms (1.79 ± 0.63 bpm). Conclusions: The statistical analysis showed good agreement between the reference system and the proposed method. In stationary conditions, the results of PRV parameters were improved by our method in comparison with data reported in related works. An overall comparative analysis of PRV parameters in motion conditions was more limited due to the lack of studies or studies containing insufficient data analysis. Based on the results, the proposed method could provide a low-cost, contactless and reliable alternative for measuring HR or PRV parameters in non-clinical environments.Peer ReviewedPostprint (published version

VIDEO KINEMATIC EVALUATION OF THE HEART (VI.KI.E.): AN IDEA, A PROJECT, A REALITY

Introduction: The technological development of the last 20 years pledges the intensity of efforts for implementing novel imaging contactless modalities that accelerate the translation from the research bench to the patient bedside, especially in the cardiac field. In this work, a novel intraoperative cardiac imaging approach, named Video Kinematic Evaluation (Vi.Ki.E.), is presented and explained in detail. This technology is able to monitor, contactless, the cardiac mechanics and deformation in-situ during heart surgery. Cardiac kinematics have been deeply evaluated ranging from the experimental animal approach to the human myocardial pathologies in both left and right ventricles. Methods: Vi.Ki.E. can be defined \u201cas simple as innovative\u201d. It only consists of a high-speed camera placed upon an exposed beating heart in-situ to record cardiac cycles. Afterwards a tracker software is used on the recorded video to follow the epicardial tissue movements. This tracker provides information about trajectories of the epicardium and, thanks to a custom-made algorithm, the technology supplies heart mechanical information such as: Force of contraction or cardiac fatigue, Energy expenditure, Contraction velocity, displacement of the marker and epicardial torsion. This approach has been tested on 21 rats (9 ischemia/reperfusion and/or for validation, 12 for the gender difference study) and on 37 patients who underwent different surgery between 2015 and 2019. In detail 10 patients underwent Coronary Artery Bypass Grafting, 12 underwent Valve Replacement after Tetralogy of Fallot correction surgery, 6 implanted a Left Ventricular Assist Device (1 is moved in the case study section), 6 patients with Hypoplastic Heart Syndrome underwent GLENN or FONTAN surgery, 2 patients underwent Heart Transplantation and finally 1 patient underwent double valve replacement (this patient is moved into case study section). Results: The patients\u2019 results demonstrated that the Vi.Ki.E. technology was able to discriminate, with statistic potency, the kinematic differences before and after the surgery in real-time, suggesting possible clinical implications in the treatment of the patients before the chest closure and/or in the intensive care unit. As it concerns the experimental animals, the results are the basics of the validation technology. Some of them were used as accepted model in comparison with the Vi.Ki.E. results on patients. Conclusions: In conclusion, this study has shown that Vi.Ki.E. is a safe and contactless technology with promising possible clinical application. The ease in the evaluation and the algorithm-based approach makes Video Kinematic Evaluation a widespread technique from cellular level to human cases covering the entire experimental field with in-vivo evaluation and possibly Langendorff/Working Heart approaches

VIDEO KINEMATIC EVALUATION OF THE HEART (VI.KI.E.): AN IDEA, A PROJECT, A REALITY

Introduction: The technological development of the last 20 years pledges the intensity of efforts for implementing novel imaging contactless modalities that accelerate the translation from the research bench to the patient bedside, especially in the cardiac field. In this work, a novel intraoperative cardiac imaging approach, named Video Kinematic Evaluation (Vi.Ki.E.), is presented and explained in detail. This technology is able to monitor, contactless, the cardiac mechanics and deformation in-situ during heart surgery. Cardiac kinematics have been deeply evaluated ranging from the experimental animal approach to the human myocardial pathologies in both left and right ventricles. Methods: Vi.Ki.E. can be defined \u201cas simple as innovative\u201d. It only consists of a high-speed camera placed upon an exposed beating heart in-situ to record cardiac cycles. Afterwards a tracker software is used on the recorded video to follow the epicardial tissue movements. This tracker provides information about trajectories of the epicardium and, thanks to a custom-made algorithm, the technology supplies heart mechanical information such as: Force of contraction or cardiac fatigue, Energy expenditure, Contraction velocity, displacement of the marker and epicardial torsion. This approach has been tested on 21 rats (9 ischemia/reperfusion and/or for validation, 12 for the gender difference study) and on 37 patients who underwent different surgery between 2015 and 2019. In detail 10 patients underwent Coronary Artery Bypass Grafting, 12 underwent Valve Replacement after Tetralogy of Fallot correction surgery, 6 implanted a Left Ventricular Assist Device (1 is moved in the case study section), 6 patients with Hypoplastic Heart Syndrome underwent GLENN or FONTAN surgery, 2 patients underwent Heart Transplantation and finally 1 patient underwent double valve replacement (this patient is moved into case study section). Results: The patients\u2019 results demonstrated that the Vi.Ki.E. technology was able to discriminate, with statistic potency, the kinematic differences before and after the surgery in real-time, suggesting possible clinical implications in the treatment of the patients before the chest closure and/or in the intensive care unit. As it concerns the experimental animals, the results are the basics of the validation technology. Some of them were used as accepted model in comparison with the Vi.Ki.E. results on patients. Conclusions: In conclusion, this study has shown that Vi.Ki.E. is a safe and contactless technology with promising possible clinical application. The ease in the evaluation and the algorithm-based approach makes Video Kinematic Evaluation a widespread technique from cellular level to human cases covering the entire experimental field with in-vivo evaluation and possibly Langendorff/Working Heart approaches