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Physiological Measurement

Spencer J Williams, Mark Porter, Juliette Westbrook, Gerrard Francis Rafferty, Victoria MacBean
Parasternal intercostal muscle electromyography (EMGpara) has been used as an index of respiratory load in health and disease. While reference values are available, such data have been obtained with subjects in the seated position only. The objective of the current study was to determine the influence of posture on measurements of EMGpara.
 Approach: Fifty-one healthy adult participants underwent measurement of EMGpara, respiratory flow and volume in the seated, reclined at 45 degrees, and supine positions...
January 16, 2019: Physiological Measurement
Paolo Riccardo Brustio, Roberto Casale, Giampiero Buttacchio, Marzia Calabrese, Marco Bruzzone, Alberto Rainoldi, Gennaro Boccia
The neuromuscular quickness capacity can be assessed calculating the rate of torque development (RTD) during ballistic contractions of maximal (RTDmaximal) or submaximal (RTDsubmaximal) amplitudes. In a series of ballistic contractions of submaximal amplitudes, RTD scaling factor (RTD-SF) represents the slope of the linear regression between achieved peak torques and the corresponding RTD. We firstly investigated if the RTD-SF contributes to predict, together with maximal voluntary torques (MVT), the RTDmaximal...
January 16, 2019: Physiological Measurement
Wee-Lih Lee, Nicholas Campbell Sinclair, Mary Jones, Joy Lynn Tan, Elizabeth Libby Proud, Richard Peppard, Hugh J McDermott, Thushara Perera
Quantification of bradykinesia (slowness of movement) is crucial for the treatment and monitoring of Parkinson's disease. Subjective observational techniques are the de-facto 'gold standard', but such clinical rating scales suffer from poor sensitivity and inter-rater variability. Although various technologies have been developed for assessing bradykinesia in recent years, most still require considerable expertise and effort to operate. Here we present a novel method to utilize an inexpensive off-the-shelf hand-tracker (Leap Motion) to quantify bradykinesia...
January 16, 2019: Physiological Measurement
Ayan Mukherjee, Anirban Dutta Choudhury, Shreyasi Datta, Chetanya Puri, Rohan Banerjee, Rituraj Singh, Arijit Ukil, Soma Bandyopadhyay, Arpan Pal, Sundeep Khandelwal
Atrial Fibrillation (AF) and other types of abnormal heart rhythms are related to multiple fatal cardiovascular diseases that impact the quality of human life. Hence, the development of an automated robust method that can reliably detect AF in addition to other non-sinus and sinus rhythms can aid in better dispersion of medical care. The present study focuses on developing an algorithm for classification of short, single lead Electrocardiogram (ECG) recordings into <i>normal</i>, <i>AF</i>, <i>other</i> abnormal rhythms and <i>noisy </i>classes...
January 16, 2019: Physiological Measurement
Nicholas G Murray, Brian Szekely, Ryan Moran, Gregory Ryan, Douglas Powell, Barry A Munkasy, Thomas Buckley, Kevin Guskiewicz
OBJECTIVE: Postural control deficits have been extensively reported following sport-related concussions. Concussed athletes demonstrate these deficits as early as 24 hours post-concussion and may persist for up to six months. Many of these prior studies have included mixed samples with prior injury history that may affect the postural control data. The purpose of this investigation was to evaluate the effect of concussion history on postural control 24-48 hours following sport-related concussion in Division I athletes...
January 9, 2019: Physiological Measurement
Remi Kowalski, Jonathan P Mynard, Joseph J Smolich, Michael M H Cheung
Wave intensity (WI) and wave power (WP) analyses are powerful approaches for assessing ventricular-vascular interactions and arterial dynamics using invasive and non-invasive methods. However, in vivo comparison of these methods for large arteries is lacking. This study assessed agreement, correlation and relative changes in wave size in invasive and non-invasive aortic WI/WP analyses, and associated sources of error. 
 Methods: The proximal descending thoracic aorta (DTA) of nine wethers was instrumented with a micromanometer and perivascular transit-time flow probe to measure high-fidelity blood pressure (P) and flow (Q) for invasive WI/WP analyses at baseline and during haemodynamic perturbations produced by cardiac pacing, distal DTA constriction and dobutamine-induced inotropic stimulation...
January 9, 2019: Physiological Measurement
Richard Charles Stoneham, Gill Barry, Lee Saxby, Michael Wilkinson
OBJECTIVE: The purpose of this study was to quantify measurement error of 3-D kinematic and kinetic measures during overground endurance running between two sessions separated by 48 hours. APPROACH: 13 recreational runners were assessed on two occasions while running overground, over embedded force plates and through an array of 3-D cameras. MAIN RESULTS: In the sagittal, frontal and transverse planes, over the entire stance phase, the typical error of kinematic variables ranged from 1...
December 21, 2018: Physiological Measurement
Jatinder Singh Minhas, Charlotte Kennedy, Thompson G Robinson, Ronney B Panerai
 Capnography is a key monitoring intervention in several neurologically vulnerable clinical states. Cerebral autoregulation (CA) describes the ability of the cerebrovascular system to maintain a near constant cerebral blood flow (CBF) throughout fluctuations in systemic arterial blood pressure (ABP), with the partial pressure of arterial carbon dioxide (PaCO<sub>2</sub>) known to directly influence CA. Previous work has demonstrated dysautoregulation lasting around 30 seconds prior to the anticipated augmentation of hyperventilation-associated hypocapnia...
December 21, 2018: Physiological Measurement
Xiuyun Liu, Kais Gadhoumi, Ran Xiao, Nate Tran, Peter Smielewski, Marek Czosnyka, Steven W Hetts, Nerissa Ko, Xiao Hu
Cerebrovascular reactivity (CR) is a mechanism that maintains stable blood flow supply to the brain. Pressure reactivity index (PRx), the correlation coefficient between slow waves of invasive arterial blood pressure (ABP) and intracranial pressure (ICP) has been validated for CR assessment. However, in clinical ward, not every subarachnoid hemorrhage (SAH) patient has invasive ABP monitoring. Pulse transit time (PTT), the propagation time of a pulse wave travelling from the heart to peripheral arteries, has been suggested as a surrogate measure of ABP...
December 21, 2018: Physiological Measurement
Jana Pokorná, Erik Staffa, Vladimír Čan, Vladan Bernard, Vojtěch Mornstein, Martina Farkašová, Andrea Zetelová, Zdeněk Kala
 Surgical resection of a part of the intestine is a standard procedure in gastrointestinal surgery and in order to perform this type of surgery successfully, tissue blood flow must be evaluated clearly. There exists a theoretical indication that the Infrared thermography (IRT) would be possible to use for this purpose. Therefore, the main objective of the study is the qualitative evaluation of the infrared thermography method as an ancillary method for determining the resection lines and forming an optimal intestinal anastomosis on the porcine model...
December 21, 2018: Physiological Measurement
Frida Sandberg, Mattias Holmer, Bo Olde
OBJECTIVE: Although respiratory problems are common among patients with end-stage renal disease, respiration is not continuously monitored during dialysis. The purpose of the present study is to investigate the feasibility of monitoring respiration using the pressure sensors of the dialysis machine. APPROACH: Respiration induces variations in the blood pressure that propagates to the extracorporeal circuit of the dialysis machine. However, the magnitude of these variations are very small compared to pressure variations induced by the dialysis machine...
December 18, 2018: Physiological Measurement
Murad Megjhani, Ayham Alkhachroum, Kalijah Terilli, Jenna Ford, Clio Rubinos, Julie Kromm, Brendan K Wallace, E Sander Connolly, David Roh, Sachin Agarwal, Jan Claassen, Raghav Padmanabhan, Xiao Hu, Soojin Park
Intracranial pressure (ICP) is an important and established clinical measurement that is used in the management of severe acute brain injury. ICP waveforms are usually triphasic and are susceptible to artifact because of transient catheter malfunction or routine patient care. Existing methods for artifact detection include threshold-based, stability-based, or template matching, and result in higher false positives (when there is variability in the ICP waveforms) or higher false negatives (when the ICP waveforms lack complete triphasic components but are valid)...
December 18, 2018: Physiological Measurement
Priscila Custódio Martins, Fernanda Hansen, Analiza Mónica Silva, Diego Augusto Santos Silva
The objective was to compare indicators of fluid distribution and cellular integrity in university athletes. Cross-sectional study with 167 university athletes (18-35 years), of team and individual sports. The bioimpedance was used to measure body water (TBW), intracellular water (ICW), extracellular water (ECW), ECW/ICW, impedance (Z), reactance (Xc), resistance (R), phase angle, body cell mass (BCM) and ECW/BCM at frequency 50khz. To measure lean soft tissue mass and body fat was used the dual-emission X-ray absorptiometry (DXA)...
December 17, 2018: Physiological Measurement
Rebecca Doran Butler, Ryan J Halter
OBJECTIVE: Multiple surgical procedures require drilling through bone to access underlying anatomy or for device placement. In dental applications, iatrogenic injury caused by accidental perforation of cortical bone into critical anatomy occurs in a significant number of dental implant procedures. Limited real-time sensing methods are available to guide clinicians while drilling through cancellous bone towards cortical interfaces. Early interface detection could prevent accidental damage to underlying anatomic structures...
December 10, 2018: Physiological Measurement
Maksym Gaiduk, Thomas Penzel, Juan Antonio Ortega, Ralf Seepold
OBJECTIVE: This paper presents an algorithm for non-invasive sleep stage identification using respiratory, heart rate and movement signals. The algorithm is part of a system suitable for long-term monitoring in a home environment, which should support experts analysing sleep. APPROACH: As there is a strong correlation between bio-vital signals and sleep stages, multinomial logistic regression was chosen for categorical distribution of sleep stages. Several derived parameters of three signals (respiratory, heart rate and movement) are input for the proposed method...
December 4, 2018: Physiological Measurement
Hisham ElMoaqet, Jungyoon Kim, Thomas Penzel
Apneas are the most common type of sleep-related breathing disorders; they cause patients to move from restorative sleep into inefficient sleep. The American Academy of Sleep Medicine (AASM) considers sleep apnea as a hidden health crisis that affects 29.4 million adults costing USA billions of Dollars. Traditional detection methods of sleep apnea are achieved by human observation of the respiration signals. This introduces limitations in terms of access and efficiency of diagnostic sleep studies. However, alternative device technologies have limited diagnostic accuracy for detecting apnea events although many of the previous investigational algorithms are based on multiple physiological channel inputs...
November 28, 2018: Physiological Measurement
Blaž Cugmas, Eva Štruc, Janis Spigulis
Photoplethysmography (PPG) is an increasingly popular health and well-being tool for monitoring heart rate and oxygen saturation. Due to pigmentation and hairiness of dogs and cats, a pulse oximeter is routinely placed solely on the tongue. As this approach is feasible only for the pet monitor use during surgical procedures, we investigate PPG signal quality on several other measurement sites that would be better tolerated by conscious animals.
 Approach: Acquired PPG signals are analyzed by four signal quality indices (SQI): mean baseline, signal power, kurtosis, and tolerance score...
November 27, 2018: Physiological Measurement
Berend E Westerhof, Nico Westerhof
In hypertension research aortic pressure wave travel and wave shape play a central role. Presently the explanation of aortic pressure is mainly based on wave travel and reflection in tube models with a single distal reflection. Increased pulse pressure with age is assumed to result from increased magnitude of distal reflection (higher SVR), and earlier return of the reflected wave (higher PWV). However, recent in vivo data show that the reflected wave runs towards the periphery rather than towards the heart as tube models predict...
November 26, 2018: Physiological Measurement
Muhammed Rizwan, Bradley M Whitaker, David V Anderson
The objective of this paper is to provide an algorithm for accurate, automated detection of atrial fibrillation from ECG signals. Four types of ECG signals are considered: normal signals, signals representing symptoms of atrial fibrillation (AF), other signals, and noisy signals. This paper represents follow-up work to the authors' entry in the 2017 PhysioNET Challenge as reported in the 2017 Computing in Cardiology Conference.
 Approach: Our approach involves extracting features from the ECG waveform and training a machine learning classifier...
November 23, 2018: Physiological Measurement
Qiao Li, Qichen Li, Chengyu Liu, Supreeth Prajwal Shashikumar, Shamim Nemati, Gari D Clifford
This study classifies sleep stages from a single lead electrocardiogram (ECG) using beat detection, cardiorespiratory coupling in the time-frequency domain and a deep convolutional neural network (CNN). 
 Approach: An ECG-derived respiration (EDR) signal and synchronous beat-to-beat heart rate variability (HRV) time series were derived from the ECG using previously described robust algorithms. A measure of cardiorespiratory coupling (CRC) was extracted by calculating the coherence and cross-spectrogram of the EDR and HRV signal in five-minute windows...
November 23, 2018: Physiological Measurement
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