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Marco A F Pimentel, Alistair E W Johnson, Peter H Charlton, Drew Birrenkott, Peter J Watkinson, Lionel Tarassenko, David A Clifton
OBJECTIVE: Current methods for estimating respiratory rate (RR) from the photoplethysmogram (PPG) typically fail to distinguish between periods of high- and low-quality input data, and fail to perform well on independent "validation" datasets. The lack of robustness of existing methods directly results in a lack of penetration of such systems into clinical practice. The present work proposes an alternative method to improve the robustness of the estimation of RR from the PPG. METHODS: The proposed algorithm is based on the use of multiple autoregressive models of different orders for determining the dominant respiratory frequency in the three respiratory-induced variations (frequency, amplitude and intensity) derived from the PPG...
November 18, 2016: IEEE Transactions on Bio-medical Engineering
Duy Dao, S M A Salehizadeh, Yeon Noj, Jo Woon Chong, Chae Cho, Dave Mcmanus, Chad E Darling, Yitzhak Mendelson, Ki H Chon
Motion and noise artifacts (MNAs) impose limits on the usability of the photoplethysmogram (PPG), particularly in the context of ambulatory monitoring. MNAs can distort PPG, causing erroneous estimation of physiological parameters such as heart rate (HR) and arterial oxygen saturation (SpO2). In this study we present a novel approach, "TifMA," based on using the Time-frequency spectrum of PPG to first detect the MNA-corrupted data and next discard the non-usable part of the corrupted data. The term "non-usable" refers to segments of PPG data from which the HR signal cannot be recovered accurately...
October 21, 2016: IEEE Journal of Biomedical and Health Informatics
Eriko Seo, Toshiyuki Sazi, Morio Togawa, Osamu Nagata, Masataka Murakami, Shigeaki Kojima, Yoshiteru Seo
Infrared photoplethysmogram (IR-PPG) and magnetic resonance image (MRI) of the Mytilus galloprovincialis heart were obtained simultaneously. Heart rate was varied by changing temperature, aerial exposure and hypoxia. Higher heart rates (35-20 beat min(-1)) were usually observed at 20°C under the aerobic condition, and typical IR-PPG represented a single peak (peak v). The upward and downward slopes of the peak v corresponded to the filling and contracting of the ventricle, respectively. A double-peak IR-PPG was observed in a wide range of heart rates (5 to 35 beats min(-1)) under various conditions...
November 15, 2016: Biology Open
Jae-Young Shin, Jun-Hwan Lee, Boncho Ku, Jang Han Bae, Min-Ho Un, Jaeuk U Kim, Tae-Hun Kim
INTRODUCTION: This study aims to investigate the effects of acupuncture stimulation on the radial artery's pressure pulse wave, along with various hemodynamic parameters, and to explore the possible underlying mechanism of pulse diagnosis in healthy participants in their twenties. METHODS AND ANALYSIS: This study is a prospective, single-arm, exploratory clinical study. A total of 25 healthy participants, without regard to gender, in their twenties will be recruited by physicians...
September 2016: Journal of Pharmacopuncture
Noriko Inoue, Hideshi Kawakami, Hideya Yamamoto, Chikako Ito, Saeko Fujiwara, Hideo Sasaki, Yasuki Kihara
The second derivative of the digital photoplethysmogram (SDPTG) is an indicator of arterial stiffness. The ratio of the height of the d wave to the a wave of the SDPTG (d/a) is associated with functional peripheral vascular tension and represents aortic-blood pressure (BP) augmented by reflection waves from the periphery. This longitudinal study aimed to investigate the relationship between SDPTG and cardiovascular mortality in middle-aged and elderly Japanese women. From 1998 to 2008, we recruited 4373 women (50-79 years old at baseline) who underwent medical check-ups and SDPTG measurement...
September 29, 2016: Hypertension Research: Official Journal of the Japanese Society of Hypertension
Xiaoman Xing, Mingshan Sun
We introduce and validate a beat-to-beat optical blood pressure (BP) estimation paradigm using only photoplethysmogram (PPG) signal from finger tips. The scheme determines subject-specific contribution to PPG signal and removes most of its influence by proper normalization. Key features such as amplitudes and phases of cardiac components were extracted by a fast Fourier transform and were used to train an artificial neural network, which was then used to estimate BP from PPG. Validation was done on 69 patients from the MIMIC II database plus 23 volunteers...
August 1, 2016: Biomedical Optics Express
Ainara Garde, Guohai Zhou, Shahreen Raihana, Dustin Dunsmuir, Walter Karlen, Parastoo Dekhordi, Tanvir Huda, Shams El Arifeen, Charles Larson, Niranjan Kissoon, Guy A Dumont, J Mark Ansermino
OBJECTIVE: Hypoxaemia is a strong predictor of mortality in children. Early detection of deteriorating condition is vital to timely intervention. We hypothesise that measures of pulse oximetry dynamics may identify children requiring hospitalisation. Our aim was to develop a predictive tool using only objective data derived from pulse oximetry and observed respiratory rate to identify children at increased risk of hospital admission. SETTING: Tertiary-level hospital emergency department in Bangladesh...
2016: BMJ Open
Wei Zong, Larry Nielsen, Brian Gross, Juan Brea, Joseph Frassica
There has been a high rate of false alarms for the critical electrocardiogram (ECG) arrhythmia events in intensive care units (ICUs), from which the 'crying-wolf' syndrome may be resulted and patient safety may be jeopardized. This article presents an algorithm to reduce false critical arrhythmia alarms using arterial blood pressure (ABP) and/or photoplethysmogram (PPG) waveform features. We established long duration reference alarm datasets which consist of 573 ICU waveform-alarm records (283 for development set and 290 for test set) with total length of 551 patent days...
August 2016: Physiological Measurement
Rui Rodrigues, Paula Couto
Our approach to detecting false arrhythmia alarms in the intensive care unit breaks down into several tasks. It involves beat detection on different signals: electrocardiogram, photoplethysmogram and arterial blood pressure. The quality of each channel has to be estimated in order to evaluate the reliability of obtained beat detections. The information about the heart rate from the different channels must be integrated in order to find a final conclusion. Some alarm types require particular detectors as is the case of ventricular fibrillation...
August 2016: Physiological Measurement
Chengyu Liu, Lina Zhao, Hong Tang, Qiao Li, Shoushui Wei, Jianqing Li
False alarm (FA) rates as high as 86% have been reported in intensive care unit monitors. High FA rates decrease quality of care by slowing staff response times while increasing patient burdens and stresses. In this study, we proposed a rule-based and multi-channel information fusion method for accurately classifying the true or false alarms for five life-threatening arrhythmias: asystole (ASY), extreme bradycardia (EBR), extreme tachycardia (ETC), ventricular tachycardia (VTA) and ventricular flutter/fibrillation (VFB)...
August 2016: Physiological Measurement
V Kalidas, L S Tamil
In this paper, as a contribution to the Physionet/Computing in Cardiology 2015 Challenge, we present individual algorithms to accurately classify five different life threatening arrhythmias with the goal of suppressing false alarm generation in intensive care units. Information obtained by analysing electrocardiogram, photoplethysmogram and arterial blood pressure signals was utilized to develop the classification models. Prior to classification, the signals were subject to a signal pre-processing stage for quality analysis...
August 2016: Physiological Measurement
Sibylle Fallet, Sasan Yazdani, Jean-Marc Vesin
The purpose of this study was to develop algorithms to lower the incidence of false arrhythmia alarms in the ICU using information from independent sources, namely electrocardiogram (ECG), arterial blood pressure (ABP) and photoplethysmogram (PPG). Our approach relies on robust adaptive signal processing techniques in order to extract accurate heart rate (HR) values from the different waveforms. Based on the quality of available signals, heart rate was either estimated from pulsatile waveforms using an adaptive frequency tracking algorithm or computed from ECGs using an adaptive mathematical morphology approach...
August 2016: Physiological Measurement
Linda M Eerikäinen, Joaquin Vanschoren, Michael J Rooijakkers, Rik Vullings, Ronald M Aarts
In this paper, we propose an algorithm that classifies whether a generated cardiac arrhythmia alarm is true or false. The large number of false alarms in intensive care is a severe issue. The noise peaks caused by alarms can be high and in a noisy environment nurses can experience stress and fatigue. In addition, patient safety is compromised because reaction time of the caregivers to true alarms is reduced. The data for the algorithm development consisted of records of electrocardiogram (ECG), arterial blood pressure, and photoplethysmogram signals in which an alarm for either asystole, extreme bradycardia, extreme tachycardia, ventricular fibrillation or flutter, or ventricular tachycardia occurs...
August 2016: Physiological Measurement
Paul S Addison
A novel method of extracting heart rate and oxygen saturation from a video-based biosignal is described. The method comprises a novel modular continuous wavelet transform approach which includes: performing the transform, undertaking running wavelet archetyping to enhance the pulse information, extraction of the pulse ridge time-frequency information [and thus a heart rate (HRvid) signal], creation of a wavelet ratio surface, projection of the pulse ridge onto the ratio surface to determine the ratio of ratios from which a saturation trending signal is derived, and calibrating this signal to provide an absolute saturation signal (SvidO2)...
June 2016: Healthcare Technology Letters
Dangdang Shao, Francis Tsow, Chenbin Liu, Yuting Yang, Nongjian Tao
We present a noncontact method to measure Ballistocardiogram (BCG) and Photoplethysmogram (PPG) simultaneously using a single camera. The method tracks the motion of facial features to determine displacement BCG, and extracts the corresponding velocity and acceleration BCGs by taking first and second temporal derivatives from the displacement BCG, respectively. The measured BCG waveforms are consistent with those reported in literature and also with those recorded with an accelerometer-based reference method...
June 29, 2016: IEEE Transactions on Bio-medical Engineering
Xiaorong Zhang, Quan Ding
This study aims to develop an accurate framework for respiratory rate (RR) monitoring from the photoplethysmogram (PPG). Sparse signal reconstruction (SSR) is used to obtain a sparse representation of the PPG signal in the spectral domain. Based on the assumption that the RR from two highly overlapped consecutive windows does not change much, RR tracking (RRT) then selects the most appropriate frequency component based on the previous RR. It also produces a signal quality index to determine whether or not to report the RR estimate for a given window...
July 2016: Physiological Measurement
Aymen A Alian, Gourg Atteya, Dorothy Gaal, Thomas Golembeski, Brian G Smith, Feng Dai, David G Silverman, Kirk Shelley
BACKGROUND: Scoliosis surgery is often associated with substantial blood loss, requiring fluid resuscitation and blood transfusions. In adults, dynamic preload indices have been shown to be more reliable for guiding fluid resuscitation, but these indices have not been useful in children undergoing surgery. The aim of this study was to introduce frequency-analyzed photoplethysmogram (PPG) and arterial pressure waveform variables and to study the ability of these parameters to detect early bleeding in children during surgery...
August 2016: Anesthesia and Analgesia
Hugo R W Touw, Milou H Verheul, Pieter R Tuinman, Jeroen Smit, Deirdre Thöne, Patrick Schober, Christa Boer
The value of capnography during procedural sedation and analgesia (PSA) for the detection of hypoxaemia during upper gastrointestinal (UGI) endoscopic procedures is limited. Photoplethysmography respiratory rate (RRp) monitoring may provide a useful alternative, but the level of agreement with capnography during PSA is unknown. We therefore investigated the level of agreement between the RRp and capnography-based RR (RRc) during PSA for UGI endoscopy. This study included patients undergoing PSA for UGI endoscopy procedures...
May 28, 2016: Journal of Clinical Monitoring and Computing
Camille L Stewart, Jane Mulligan, Greg Z Grudic, Mark E Talley, Gregory J Jurkovich, Steven L Moulton
INTRODUCTION: Humans are able to compensate for significant blood loss with little change in traditional vital signs. We hypothesized that an algorithm, which recognizes compensatory changes in photoplethysmogram (PPG) waveforms, could detect active bleeding and ongoing volume loss in injured patients. METHODS: Injured adults were prospectively enrolled at a level I trauma center. PPG data collection was conducted using a custom-made pulse oximeter. Waveform data were post-processed by an algorithm to calculate the compensatory reserve index (CRI), measured on a scale of 1 to 0, with 1 indicating fully compensated and 0 indicating no reserve, or decompensation...
September 2016: Shock
M J Butler, J A Crowe, B R Hayes-Gill, P I Rodmell
Non-contact photoplethysmography (PPG) provides multiple benefits over in-contact methods, but is not as tolerant to motion due to the lack of mechanical coupling between the subject and sensor. One limitation of non-contact photoplethysmography is discussed here, specifically looking at the topology and optical variations of the skin and how this impacts upon the ability to extract a photoplethysmogram when a subject moves horizontally across the field of view of the detector (a panning motion). When this occurs it is shown that whilst the general relationships between the speed of traversal, detection area and resultant signal quality can be found, the quality of signal in each individual case is determined by the properties of the area of skin chosen...
May 2016: Physiological Measurement
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