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Respiratory rate (RR) is a clinically important predictor of cardio-respiratory deteriorations. The mainstay of clinical measurement comprises the manual counting of chest movements, which is variable between clinicians and limited to sporadic readings. Emerging solutions are limited by poor adherence and acceptability or are not clinically validated. Albus HomeTM is a contactless and automated bedside system for nocturnal respiratory monitoring that overcomes these limitations. This study aimed to validate the accuracy of Albus Home compared to gold standards in real-world sleeping environments. Participants undertook overnight monitoring simultaneously using Albus Home and gold-standard polygraphy with thoraco-abdominal respiratory effort belts (SomnomedicsEU). Reference RR readings were obtained by clinician-count of polygraphy data. For both the Albus system and reference, RRs were measured in 30-s segments, reported as breaths/minute, and compared. Accuracy was defined as the percentage of RRs from the Albus system within ±2 breaths/minute of reference counts. Across a diverse validation set of 32 participants, the mean accuracy exceeded 98% and was maintained across different participant characteristics. In a Bland-Altman analysis, Albus RRs had strong agreement with reference mean differences and the limits of agreement of -0.4 and ±1.2 breaths/minute, respectively. Albus Home is a contactless yet accurate system for automated respiratory monitoring. Validated against gold -standard methods, it enables long-term, reliable nocturnal monitoring without patient burden. ispartof: SENSORS vol:22 issue:19 ispartof: location:Switzerland status: published

Breathing rate is considered one of the fundamental vital signs and a highly informative indicator of physiological state. Given that the monitoring of heart activity is less complex than the monitoring of breathing, a variety of algorithms have been developed to estimate breathing activity from heart activity. However, estimating breathing rate from heart activity outside of laboratory conditions is still a challenge. The challenge is even greater when new wearable devices with novel sensor placements are being used. In this paper, we present a novel algorithm for breathing rate estimation from photoplethysmography (PPG) data acquired from a head-worn virtual reality mask equipped with a PPG sensor placed on the forehead of a subject. The algorithm is based on advanced signal processing and machine learning techniques and includes a novel quality assessment and motion artifacts removal procedure. The proposed algorithm is evaluated and compared to existing approaches from the related work using two separate datasets that contains data from a total of 37 subjects overall. Numerous experiments show that the proposed algorithm outperforms the compared algorithms, achieving a mean absolute error of 1.38 breaths per minute and a Pearson’s correlation coefficient of 0.86. These results indicate that reliable estimation of breathing rate is possible based on PPG data acquired from a head-worn device.

International audience; This paper proposes an integrated model of cardio-respiratory interactions in preterm newborns, focused on the study of the patent ductus arteriosus (PDA). A formal model parameter sensitivity analysis on blood flow through the PDA is performed. Results show that the proposed model is capable of simulating hemodynamics in right-to-left and left-to-right shunts. For both configurations, the most significant parameters are associated with mechanical ventricular properties and circulatory parameters related to left ventricle loading conditions. These results highlight important physiological mechanisms involved in PDA and provide key information towards the definition of patient-specific parameters. © 2021 IEEE.

Breathing pattern (BP) is related to key psychophysiological and performance variables during exercise. Modern wearable sensors and data analysis techniques facilitate BP analysis during running but are lacking crucial validation steps in their deployment. Thus, we sought to evaluate a wearable garment with respiratory inductance plethysmography (RIP) sensors in combination with a custom-built algorithm versus a reference spirometry system to determine its concurrent validity in detecting flow reversals (FR) and BP. Twelve runners completed an incremental running protocol to exhaustion with synchronized spirometry and RIP sensors. An algorithm was developed to filter, segment, and enrich the RIP data for FR and BP estimation. The algorithm successfully identified over 99% of FR with an average time lag of 0.018 s (-0.067,0.104) after the reference system. Breathing rate (BR) estimation had low mean absolute percent error (MAPE = 2.74 [0.00,5.99]), but other BP components had variable accuracy. The proposed system is valid and practically useful for applications of BP assessment in the field, especially when measuring abrupt changes in BR. More studies are needed to improve BP timing estimation and utilize abdominal RIP during running.

Impedance pneumography (ImP) is widely used for respiratory rate (RR) monitoring. However, ImP-derived RRs can be imprecise. The aim of this study was to develop a signal quality index (SQI) for the ImP signal, and couple it with a RR algorithm, to improve RR monitoring. An SQI was designed which identifies candidate breaths and assesses signal quality using: the variation in detected breath durations, how well peaks and troughs are defined, and the similarity of breath morphologies. The SQI categorises 32 s signal segments as either high or low quality. Its performance was evaluated using two critical care datasets. RRs were estimated from high-quality segments using a RR algorithm, and compared with reference RRs derived from manual annotations. The SQI had a sensitivity of 77.7 %, and specificity of 82.3 %. RRs estimated from segments classified as high quality were accurate and precise, with mean absolute errors of 0.21 and 0.40 breaths per minute (bpm) on the two datasets. Clinical monitor RRs were significantly less precise. The SQI classified 34.9 % of real-world data as high quality. In conclusion, the proposed SQI accurately identifies high-quality segments, and RRs estimated from those segments are precise enough for clinical decision making. This SQI may improve RR monitoring in critical care. Further work should assess it with wearable sensor data.

Assessments of respiratory response and animal activity are useful endpoints in drug pharmacology and safety research. We investigated whether continuous, direct monitoring of breathing rate and body motion in animals in the home cage using the Vum Digital Smart House can complement standard measurements in enabling more granular detection of the onset and severity of physiologic events related to lung injury in a well-established rodent model of paraquat (PQ) toxicity. In rats administered PQ, breathing rate was significantly elevated while body motion was significantly reduced following dosing and extending throughout the 14-day study duration for breathing rate and at least 5 days for both nighttime and daytime body motion. Time course differences in these endpoints in response to the potential ameliorative test article bardoxolone were also readily detected. More complete than standard in-life measurements, breathing rate and body motion tracked injury progression continuously over the full study time period and aligned with, and informed on interval changes in clinical pathology. In addition, breathing rates correlated with terminal pathology measurements, such as normalized lung weights and histologic alveolar damage and edema. This study is a preliminary evaluation of the technology; our results demonstrate that continuously measured breathing rate and body motion served as physiologically relevant readouts to assess lung injury progression and drug response in a respiratory injury animal model.

We aimed to compare the change in exercise response to taekwondo-specific circuit workouts before and after competition rule amendments. A total of 240 workouts in 15 elite athletes were analyzed over two years. Physiological and kinematic data were gathered with the wireless Bioharness system along with capillary blood samples for lactate concentration. Progressive exercise tests until exhaustion were periodically performed to obtain reference data. The rule changes resulted in significant increases (mainly medium or large effects) in the physiological (2.9&ndash, 14.4%) and kinematic (4.8&ndash, 10.1%) response to taekwondo-specific workouts. The largest increases were for peak breathing rate (12.0%), energy expenditure (6.6%), blood lactate immediately after exercise (10.2%) and at the 30th min of recovery (14.4%), and peak kinematic activity (10.1%). Significant differences between taekwondo-specific workouts and tournament combats persisted after the shift from old to new rules, ranging from 2.4 to 38.5% for physiological and from 2.9 to 15.5% for kinematic variables. The largest workout&ndash, combat differences were revealed for post-exercise (15.9%) and recovery (38.5%) blood lactate, peak (&minus, 15.8%) and relative (&minus, 15.0%) breathing rate, and mechanical (13.5%) and physiological (14.2%) intensity. Our study suggests that the rule amendments significantly modify the exercise response to discipline-specific workouts and that taekwondo-specific training sessions do not fully recreate the tournament demands in terms of physiological and kinematic load.

International audience; Objective The objective of this paper is to obtain accurate estimation of breathing rate (BR), using only the electrocardiogram (ECG) or the photoplethysmogram (PPG) signals, to avoid wearing cumbersome and uncomfortable sensors for direct measurements. Methods Several respiration waveforms are derived from ECG or PPG signals based on amplitude, frequency, and baseline wander modulations. It is, however, difficult to determine their optimal combination for BR estimation due to the noise and patient specificity. We first propose to quantify the quality of modulation waveforms using respiratory quality indices (RQIs). We then present two methods the first automatically selects the modulation signal with highest RQI for BR estimation, and the second tracks the respiration signal using the Kalman smoother to fuse modulation signals with highest RQI. Results These two methods are evaluated on two independent datasets, one benchmark database (DB) with immobilized patients recordings and the second with those performing daily activities. Our results outperform existing methods in the literature in both the cases. Conclusion Experimental results show that the RQIs coupled with a fusion algorithm increases the accuracy for BR estimations in dealing with derived modulation signals. Significance This work describes a robust Kalman Smoother method applicable in multiple clinical contexts to improve breathing rate estimation from data fusion. © 1964-2012 IEEE.

Global Proprioceptive Resonance (GPR) is a recently developed approach conceived to solicit the various cutaneous mechanoreceptors, through application of mechanical multifocal vibration at low amplitude and at definite body sites, limiting the stimulation of the profound structures. This interventional study evaluated the effects of GPR on cardiorespiratory function during the post-exertional recovery period. A group of volunteers involved in Triathlon (a multisport discipline consisting of sequential swim, cycle, and run disciplines higly demanding in terms of metabolic engagment), underwent two maximal incremental exercise tests until exhaustion followed alternatively to (a) a 13 minutes section of GPR or (b) a standard low intensity exercise acute trend of the same duration. These effects of these two approaches were compared in terms of recovery of: heart rate (HR), respiratory rate (RR), peripheral oxygen saturation (SpO2) and venous lactate concentration (Lac). The physiological parameters (HR, RR, SpO2 and Lac) recorded in the pre-exertion session showed similar values between the 40 volunteers while several differences were recorded in the post-exertion phase. After 6 min of GPR recovery it was recorded a drop in RR below baseline (19.4±4.15 min-1 vs. 12.2± 0.4 min-1; p

The aim of this paper is designing an algorithm dubbed "pattern" to detect electrocardiogram (ECG) components accurately by searching exactly in the right places of peaks and getting exhaustive information related to the heart. Then, using the obtained results to propose a method for constructing respiration signal properly, by calculating the mean of R peaks to determine inspiration and expiration phases and calculating the amount of change for other peaks to be added during inspiration phase and subtracted during the expiration phase. The proposed method improves envelope method which only depends on the size of R to construct respiration signals. The results show that the pattern algorithm is guaranteed method and useful for detecting ECG components and exploiting them for constructing respiration signal work better than envelope method.

Objective: The simple observation of breathing rate (BR) remains the first and often the most sensitive marker of acute respiratory dysfunction. In fact, there are evidences that drastic changes in BR are a predictive indicator of adverse events (i.e. cardiac arrest). The aim of this study is to develop a camera-based technology that may provide near-continuously estimation of BR considering the effect of respiration on videoPPG (vPPG). Approach: The technology has been tested in two different experimental settings, including controlled BR and more challenging scenarios with spontaneous breathing pattern. Video data were processed offline to derive the vPPG signal. The method derives respiration from beat-to-beat PPG rate and morphology changes in amplitude and width driven by the physiological relationships between vPPG and respiration. Moreover, respiratory-induced head movements were used as additional source of information for the vPPG system. A combination of these methods has been exploited to estimate the respiratory rate every 10 second. Main Results: According to the results, respiratory frequencies in the central range (0.2-0.4 Hz) may be estimated using vPPG system with low relative error, eR < 2 % and interquartile range of order IQR < 5 %. However, the vPPG system showed a drop in performance at respiratory range boundaries, around 0.1 Hz and 0.5 Hz. Significance: This camera-based technology can be used as ubiquitous BR monitoring system. However, vPPG-based systems should consider the effect of the BR in the estimation, mainly in applications where respiratory rate is out of the range 0.2-0.4 Hz.

This study is based on the relationship between meditation, the present moment, and psychophysiology. We employed the metronome task to operationalize the extension of the present moment. A pre-post longitudinal study was conducted. The performance in the metronome task was compared before and after the interventions (meditation, story). The aim was to assess whether physiological changes (heart, breathing) during meditation influence the temporal-integration (TI) of metronome beats. Mindfulness meditators either meditated (n = 41) or listened to a story (n = 43). The heart and breathing activity were recorded during the intervention and compared to a resting-state condition. By applying path analyses we found that meditation led to an increase of the duration of integration intervals at the slowest metronome frequency (inter-stimulus interval, ISI = 3 s). After meditation, the higher the heart-rate variability (i.e., the root mean square of successive differences, RMSSD), the longer the duration of integration intervals at the fastest frequency (ISI = 0.33 s). Moreover, the higher the breathing rate during meditation, the greater the integration of intervals at ISI = 1 s. These findings add evidence to meditation-induced changes on the TI of metronome beats and the concept of the embodiment of mental functioning.

Purpose: Extracorporeal membrane oxygenation (ECMO) is a rescue therapy for patients with acute respiratory distress syndrome (ARDS). The aim of this study was to evaluate associations between ventilatory settings during ECMO for refractory hypoxemia and outcome in ARDS patients. Methods: In this individual patient data meta-analysis of observational studies in adult ARDS patients receiving ECMO for refractory hypoxemia, a time-dependent frailty model was used to determine which ventilator settings in the first 3 days of ECMO had an independent association with in-hospital mortality. Results: Nine studies including 545 patients were included. Initiation of ECMO was accompanied by significant decreases in tidal volume size, positive end-expiratory pressure (PEEP), plateau pressure, and driving pressure (plateau pressure − PEEP) levels, and respiratory rate and minute ventilation, and resulted in higher PaO2/FiO2, higher arterial pH and lower PaCO2 levels. Higher age, male gender and lower body mass index were independently associated with mortality. Driving pressure was the only ventilatory parameter during ECMO that showed an independent association with in-hospital mortality [adjusted HR, 1.06 (95 % CI, 1.03–1.10)]. Conclusion: In this series of ARDS patients receiving ECMO for refractory hypoxemia, driving pressure during ECMO was the only ventilator setting that showed an independent association with in-hospital mortality. © 2016, Springer-Verlag Berlin Heidelberg and ESICM.

This paper investigates the use of heart rate (HR) and breathing rate (BR) signals for the automatic recognition of car driver stress. The problem is defined as a binary classification problem, that is stress vs no-stress, and it is tackled by using the Support Vector Machines classification strategy. We propose the use of a combination of traditional state of the art features and raw values of the acquired signals as data representation. Experimentation is carried out on a subset of data belonging to a publicly available dataset of simulated driving. The HR and BR signals are acquired with an adrenergic sensor connected to a chest strap that is worn underneath the driver’s clothing. The experiments are made considering the leave-one-subject-out configuration, that is the subject under test is not included in the training set. The goodness of HR and BR is tested separately and then a combination of them. The results obtained are very encouraging, especially considering that the leave-one-subject-out configuration is adopted. The results reach a mean average accuracy of about 70% in the case where the combination of HR and BR is adopted.

Made available in DSpace on 2018-11-26T16:17:19Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-12-01 Natural Sciences and Engineering Research Council of Canada Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Fundação para o Desenvolvimento da UNESP (FUNDUNESP) The present study determined whether EEG and/or EMG recordings could be used to reliably define activity states in the Brazilian black and white tegu lizard (Tupinambis merianae) and then examined the interactive effects of temperature and activity states on strategies for matching O-2 supply and demand. In a first series of experiments, the rate of oxygen consumption (), breathing frequency (f (R)), heart rate (f (H)), and EEG and EMG (neck muscle) activity were measured in different sleep/wake states (sleeping, awake but quiet, alert, or moving). In general, metabolic and cardio-respiratory changes were better indictors of the transition from sleep to wake than were changes in the EEG and EMG. In a second series of experiments, the interactive effects of temperature (17, 27 and 37 A degrees C) and activity states on f (R), tidal volume (V (T)), the fraction of oxygen extracted from the lung per breath (FIO2-FEO2), f (H), and the cardiac O-2 pulse were quantified to determine the relative roles of each of these variables in accommodating changes in . The increases in oxygen supply to meet temperature- and activity-induced increases in oxygen demand were produced almost exclusively by increases in f (H) and f (R). Regression analysis showed that the effects of temperature and activity state on the relationships between f (H), f (R) and was to extend a common relationship along a single curve, rather than separate relationships for each metabolic state. For these lizards, the predictive powers of f (R) and f (H) were maximized when the effects of changes in temperature, digestive state and activity were pooled. However, the best r (2) values obtained were 0.63 and 0.74 using f (R) and f (H) as predictors of met abolic rate, respectively. Univ British Columbia, Dept Zool, Vancouver, BC V6T 1Z4, Canada Univ Estadual Paulista Rio Claro, Inst Nacl Ciencia & Tecnol Fisiol, Dept Zool, Rio Claro, SP, Brazil Brock Univ, Dept Biol Sci, St Catharines, ON L2S 3A1, Canada Univ Estadual Paulista Rio Claro, Inst Nacl Ciencia & Tecnol Fisiol, Dept Zool, Rio Claro, SP, Brazil

Maternal heat stress during late gestation affects calf function during postnatal life. The objective of the present study was to evaluate whether calves that experience heat stress in utero have altered thermoregulatory responses to acute heat stress later in life. Specifically, the hypothesis was that heat stress in utero would improve the response to acute heat stress at maturity. Females were born to dams exposed to heat stress or cooled during late gestation preceding their birth. All animals were raised postnatally under identical management. Twelve lactating Holstein cows that were exposed to in utero heat stress (HT) and 12 that were exposed to in utero control (CON) were used. A heat stress challenge was conducted in 3 blocks using 4 HT and 4 CON cows matched according to milk yield, stage of lactation, and parity. Each challenge consisted of transfer from a barn with shade and evaporative cooling to one with shade but no additional cooling for 48 h. The challenge was replicated twice for each block. Sweating rate, respiration rate, rectal temperature (RT), and skin temperature were measured on each cow at 0900, 1100, 1300, 1500, and 1700 h for 2 consecutive days. Mean ambient temperature across 6 challenge days was 26.15 +/- 4.75 degrees C. Tendencies for differences at 1700 h were observed between treatments for RT (HT: 39.5 +/- 0.1; CON: 39.6 +/- 0.1 degrees C; P = 0.065), however, there was no difference in respiration rate (HT: 77.6 +/- 1.6; CON: 79.5 +/- 1.6 bpm; P = 0.85). Sweating rate for shaved skin (HT: 29.4 +/- 2.0; CON: 36.0 +/- 2.0 g/m(2)h; P = 0.057) and for non-shaved skin (HT: 22.5 +/- 1.5; CON: 29.2 +/- 1.2 g/m(2)h; P = 0.01) differed between groups. However, there was no effect on skin temperature at the shaved location (HT: 36.2 +/- 0.2; CON: 36.0 +/- 0.2 degrees C; P = 0.81), but there was a tendency for differences for the non-shaved area (HT: 35.4 +/- 0.2; CON: 34.9 +/- 0.2 degrees C; P = 0.097). Cows that underwent in utero heat stress had greater skin temperature at 1700 h vs. in utero control cows, which may be because HT cows increased skin perfusion, and consequently greater cooling via conduction. In utero HT cows would then have higher heat loss and reduced core body temperature, which results in lower rectal temperature and lower sweating rate when exposed to heat stress. These results support the hypothesis that heat stress in utero in late gestation increases heat tolerance at maturity by increasing capacity to dissipate heat to maintain core body temperature.

Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-27T11:30:32Z No. of bitstreams: 0 Made available in DSpace on 2014-05-27T11:30:32Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-09-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) This study examined the distribution and orientation of gill O2 chemoreceptors in Oreochromis niloticus and their role in cardiorespiratory responses to graded hypoxia. Intact fish, and a group with the first gill arch excised (operated), were submitted to graded hypoxia and their cardiorespiratory responses (oxygen uptake - V̇O2, breathing frequency - fR, ventilatory stroke volume - VT, gill ventilation - V̇G, O2 extraction from the ventilatory current - EO2, and heart rate - fH) were compared. Their responses to bolus injections of NaCN into the bloodstream (internal) or ventilatory water stream (external) were also determined. The V̇O2 of operated fish was significantly lower at the deepest levels of hypoxia. Neither reflex bradycardia nor ventilatory responses were completely abolished by bilateral excision of the first gill arch. EO2 of the operated group was consistently lower than the intact group. The responses to internal and external NaCN included transient decreases in fH and increases in fR and Vamp (ventilation amplitude). These cardiorespiratory responses were attenuated but not abolished in the operated group, indicating that chemoreceptors are not restricted to the first gill arch, and are sensitive to oxygen levels in both blood and water. © 2013 Elsevier Inc. Department of Physiological Sciences Laboratory of Zoophysiology and Comparative Biochemistry Federal University of São Carlos (UFSCar), P.O. Box 676, Via Washington Luis, km 235, 13565-905 São Carlos, SP Department of Zoology and Botany São Paulo State University - UNESP/IBILCE, Rua Cristóvão Colombo, 2265, 15054-000 - São José do Rio Preto, SP National Institute of Science and Technology - Comparative Physiology (FAPESP/CNPq) Department of Zoology and Botany São Paulo State University - UNESP/IBILCE, Rua Cristóvão Colombo, 2265, 15054-000 - São José do Rio Preto, SP FAPESP: 10/03599-2

Although there is growing evidence that breathing is modulated by various motor and cognitive activities, the nature of breathing in musical performance has been little explored. The present study examined the temporal breath pattern in piano performance, aiming to elucidate how breath timing is related to musical organization/events and performance. In the experiments, the respiration of 15 professional and amateur pianists, playing 10 music excerpts in total (from four-octave C major scale, Hanon's exercise, J. S. Bach's Invention, Mozart's Sonatas, and Debussy's Clair de lune), was monitored by capnography. The relationship between breathing and musical characteristics was analyzed. Five major results were obtained. (1) Mean breath interval was shortened for excerpts in faster tempi. (2) Fluctuation of breath intervals was reduced for the pieces for finger exercise and those in faster tempi. Pianists showing large within-trial fluctuation also exhibited large inter-excerpt difference. (3) Inter-trial consistency of the breath patterns depended on the excerpts. Consistency was generally reduced for the excerpts that could be performed mechanically (i.e., pieces for finger exercise), but interestingly, one third of the participant showed consistent patterns for the simple scale, correlated with the ascending/descending sequences. (4) Pianists tended to exhale just after the music onsets, inhale at the rests, and inhibit inhale during the slur parts. There was correlation between breathing pattern and two-voice polyphonic structure for several participants. (5) Respiratory patterns were notably different among the pianists. Every pianist showed his or her own characteristic features commonly for various musical works. These findings suggest that breathing in piano performance depends not only on musical parameters and organization written in the score but also some pianist-dependent factors which might be ingrained to individual pianists.

Arachidonic acid (AA) is a polyunsaturated fatty acid that is present in the phospholipids of the cell membranes of the body and is abundant in the brain. Exogenously administered AA has been shown to affect brain metabolism and to exhibit cardiovascular and neuroendocrine actions. However, little is known regarding its respiratory actions and/or central mechanism of its respiratory effects. Therefore, the present study was designed to investigate the possible effects of centrally injected AA on respiratory system and the mediation of the central cyclooxygenase (COX) to thromboxane A2 (TXA2) signaling pathway on AA-induced respiratory effects in anaesthetized rats. Intracerebroventricular (i.c.v.) administration of AA induced dose- and time-dependent increase in tidal volume, respiratory rates and respiratory minute ventilation and also caused an increase in partial oxygen pressure (pO2) and decrease in partial carbon dioxide pressure (pCO2) in male anaesthetized Sprague Dawley rats. I.c.v. pretreatment with ibuprofen, a non-selective COX inhibitor, completely blocked the hyperventilation and blood gases changes induced by AA. In addition, central pretreatment with different doses of furegrelate, a TXA2 synthesis inhibitor, also partially prevented AA-evoked hyperventilation and blood gases effects. These data explicitly show that centrally administered AA induces hyperventilation with increasing pO2 and decreasing pCO2 levels which are mediated by the activation of central COX to TXA(2) signaling pathway. (C) 2016 Elsevier B.V. All rights reserved.

Background: Stress index at post-recruitment maneuvers could be a method of positive end-expiratory pressure (PEEP) titration in acute respiratory distress syndrome (ARDS) patients. However, airway pressure (Paw) stress index may not reflect lung mechanics in the patients with high chest wall elastance. This study was to evaluate the Pawstress index on lung mechanics and the correlation between Pawstress index and transpulmonary pressure (PL) stress index in acute respiratory failure (ARF) patients. Methods: Twenty-four ARF patients with mechanical ventilation (MV) were consecutively recruited from July 2011 to April 2013 in Zhongda Hospital, Nanjing, China and Ospedale S. Giovanni Battista-Molinette Hospital, Turin, Italy. All patients underwent MV with volume control (tidal volume 6 ml/kg) for 20 min. PEEP was set according to the ARDSnet study protocol. The patients were divided into two groups according to the chest wall elastance/respiratory system elastance ratio. The high elastance group (H group, n = 14) had a ratio ≥30%, and the low elastance group (L group, n = 10) had a ratio

This study is to investigate the effects of slow breathing on heart rate variability (HRV) and arterial baroreflex sensitivity in essential hypertension. We studied 60 patients with essential hypertension and 60 healthy controls. All subjects underwent controlled breathing at 8 and 16 breaths per minute. Electrocardiogram, respiratory, and blood pressure signals were recorded simultaneously. We studied effects of slow breathing on heart rate, blood pressure and respiratory peak, high-frequency (HF) power, low-frequency (LF) power, and LF/HF ratio of HRV with traditional and corrected spectral analysis. Besides, we tested whether slow breathing was capable of modifying baroreflex sensitivity in hypertensive subjects. Slow breathing, compared with 16 breaths per minute, decreased the heart rate and blood pressure (all P

Continued developments of sensor technology including hardware miniaturization and increased sensitivity have enabled the development of less intrusive methods to monitor physiological parameters during daily life. In this work, we present methods to recover cardiac and respiratory parameters using accelerometer and gyroscope sensors on the wrist. We demonstrate accurate measurements in a controlled laboratory study where participants (n = 12) held three different positions (standing up, sitting down and lying down) under relaxed and aroused conditions. In particular, we show it is possible to achieve a mean absolute error of 1.27 beats per minute (STD: 3.37) for heart rate and 0.38 breaths per minute (STD: 1.19) for breathing rate when comparing performance with FDA-cleared sensors. Furthermore, we show comparable performance with a state-of-the-art wrist-worn heart rate monitor, and when monitoring heart rate of three individuals during two consecutive nights of in-situ sleep measurements., National Science Foundation (U.S.) (CCF-1029585), Samsung (Firm). Think Tank Team, MIT Media Lab Consortium

The aim of this study was to compare the effects of 3 different sedative-analgesic regimens in patients with intracranial mass lesions undergoing stereotactic brain biopsy. A 135 outpatients with American Society of Anesthesiologists I to II were divided into 3 groups: group A (n = 45) received a loading dose of IV alfentanil 7.5 microg/kg followed by infusion rate of 0.25 microg/kg/min; group F (n = 45) received a bolus dose of 1 microg/kg IV fentanyl and repeated as needed; and group R (n = 45) received infusion of 0.05 microg/kg/min remifentanil. Target level of sedation was 3 to 4 of the Ramsay Sedation Scale. Systolic and diastolic blood pressure, heart rate, respiratory rate, peripheric oxygen saturation (SpO2), and end-tidal carbon dioxide were recorded at different stages of the procedures. The patients in group F had significantly lower mean heart rate than those in groups A and R, but this was not in the limits of the bradycardia. The patients in group A had significantly lower mean SpO2 than those in the other groups, but mean SpO2 values did not drop below 94%. There were no significant differences in end-tidal carbon dioxide and respiratory rate values among the groups. Our results suggest that all 3 regimens have relatively similar hemodynamic and respiratory responses. The use of bolus fentanyl technique caused less hemodynamic stability. The continuous infusion technique of remifentanil or alfentanil provided better control on hemodynamic parameters.

The aim of the present study is to evaluate the analgesic activity, patient satisfaction, and side effect profile of different concentrations of levobupivacaine plus fentanyl administered through thoracic epidural patient-controlled analgesia in patients undergoing thoracotomy. The study included 60 patients who were randomly divided into three groups. At the end of the surgery, group I (n = 20) received 0.125% levobupivacaine plus 3 mg fentanyl, group II received 0.1% levobupivacaine plus 3 mg fentanyl, and group III received 0.05% levobupivacaine plus 3 mg fentanyl via an epidural catheter placed at the level of T10-11 or T11-12. For all groups, the patient-controlled analgesia device was programmed to deliver a loading dose of 14 μl at an infusion rate of 4 μl/h, and a bolus dose of 2 μl/h, with a locked out interval of 15 minutes and 60 μl of a 4-hour limit. The following parameters were evaluated at 5, 10, 15, 20, 30, and 40 minutes and at 1, 2, 4, 8, 16, and 24 hours after admission to the intensive care unit, at which nausea and vomiting scales, Visual Analog Scale I-II, Ramsay sedation scale, Bromage scale, pupil diameter, arterial blood pressure, heart rate, respiratory rate, and SpO2 were measured and recorded. Any side effect was also documented. As the result of the evaluation, visual Analog Scale I-II scores, patient satisfaction scores, mean arterial blood pressure, and heart rate significantly differed in group I as compared with groups II and III. No side effects were encountered except mild nausea, which was seen in group III and did not require treatment. Motor blockage, pupil size, respiratory rate, and SpO2 were not monitored in any of the patients in all groups. In conclusion, our study suggested that the use of 0.125% levobupivacaine, together with 3 mg/mL fentanyl, constitutes a good combination, and can be used safely without causing hemodynamic change and motor block. Copyright © 2012, Taiwan Society of Anesthesiologists.

The aim of the present study was to confirm whether feeding influences the resting breathing rate and to observe possible alterations in blood gas and pH levels produced by feeding in unanesthetized sloths (Bradypus variegatus). Five adult male sloths (4.1 +/- 0.6 kg) were placed daily in an experimental chair for a period of at least 4 h for sitting adaptation. Five measurements were made for each sloth. However, the sloths one, two and five were studied once and the sloths three and four were studied twice. Breathing rate was determined with an impedance meter and the output signal was digitized. Arterial blood samples were collected for blood gas analysis with a BGE electrolytes analyzer and adjusted for the animal's body temperature and hemoglobin content. The data are reported as mean +/- SD and were collected during the resting period (8:00-10:00 h) and during the feeding period (16:00-18:00 h). The mean breathing rate increased during mastication of ymbahuba leaves (rest: 5.0 +/- 1, feeding: 10 +/- 1 bpm). No significant alterations were observed in arterial pH (rest: 7.42 +/- 0.05, feeding: 7.45 +/- 0.03), PCO2 (rest: 35.2 +/- 5.3, feeding: 33.3 +/- 4.4 mmHg) or PO2 (rest: 77.5 +/- 8.2, feeding: 78.4 +/- 5.2 mmHg) levels. These results indicate that in unanesthetized sloths 1) feeding evokes an increase in breathing rate without a significant change in arterial pH, PCO2 or PO2 levels, and 2) the increase in breathing rate produced by feeding probably is due to the act of mastication.

The study focuses on psychological and physical effects of stress while performing community garden activities of various intensity levels. The aim of this study was to determine the psychological and physical effects in adults with (case group) and without (control group) mental disabilities. Salivary α-amylase (sAA) levels and the stress response scale (SRS-18) were used for the psychological analysis (n = 42). For physical assessment (n = 13), electrocardiogram (ECG), surface electromyogram (sEMG), and respiration rate were continuously measured while performing the activities using a multichannel telemetry system. The results showed that following the activities, the case group exhibited decreasing sAA levels while control group exhibited increasing sAA levels. However, both groups exhibited lower SRS-18 results following the activities. Compared with the control group, the case group had a significantly lower increase in the ratio of the heart rate (IRHR) (5.5%) during low-intensity work (filling pots with soil), but a significantly higher IRHR (16.7%) during high-intensity work (turning over soil). The case group experienced significantly higher levels of fatigue during high-intensity work (digging) than during the rest condition. These findings indicate that appropriate workload allocation, according to health, is necessary in the community garden setting because reducing the intensity of work assignments for people with mental disabilities will reduce their physical stress.

The SLICK haplotype (http://omia.angis.org.au/OMIA001372/9913/) in cattle confers animals with a short and sleek hair coat. Originally identified in Senepol cattle, the gene has been introduced into Holsteins. The objectives of the current study were to determine (1) whether lactating Holsteins with the slick hair phenotype have superior ability for thermoregulation compared with wild-type cows or relatives not inheriting the SLICK haplotype, and (2) whether seasonal depression in milk yield would be reduced in SLICK cows. In experiment 1, diurnal variation in vaginal temperature in the summer was monitored for cows housed in a freestall barn with fans and sprinklers. Vaginal temperatures were lower in slick-haired cows than in relatives and wild-type cows. In experiment 2, acute responses to heat stress were monitored after cows were moved to a dry lot in which the only heat abatement was shade cloth. The increases in rectal temperature and respiration rate caused by heat stress during the day were lower for slick cows than for relatives or wildtype cows. Moreover, sweating rate was higher for slick cows than for cows of the other 2 types. In experiment 3, effects of season of calving (summer vs. winter) on milk yield and composition were determined. Compared with milk yield of cows calving in winter, milk yield during the first 90 d in milk was lower for cows calving in the slimmer. However, this reduction was less pronounced for slick cows than for wild-type cows. In conclusion, Holsteins with slick hair have superior thermoregulatory ability compared with non-slick animals and experience a less drastic depression in milk yield during the summer. USDA National Institute of Food and Agriculture (Washington, DC) (2010-85122-20623) (2013-68004-20365) Southeast Milk Inc. Milk Check-off Program

This paper presents the preliminary results of our work in detecting respiration using Doppler Radar in the 2.7 GHz operating band. We demonstrate the capability of Doppler Radar in capturing breathing patterns under various breathing forms such as normal breathing, fast breathing, as well as different rate of inhale and exhale. From the captured signals, respiration rate was obtained using Fast Fourier Transform and validated. The proposed approach could potentially be used in number of applications involving breathing rate and breathing pattern analysis via non-contact methods. Refereed/Peer-reviewed

IMPORTANCE: Definitions of sepsis and septic shock were last revised in 2001. Considerable advances have since been made into the pathobiology (changes in organ function, morphology, cell biology, biochemistry, immunology, and circulation), management, and epidemiology of sepsis, suggesting the need for reexamination.OBJECTIVE: To evaluate and, as needed, update definitions for sepsis and septic shock.PROCESS: A task force (n = 19) with expertise in sepsis pathobiology, clinical trials, and epidemiology was convened by the Society of Critical Care Medicine and the European Society of Intensive Care Medicine. Definitions and clinical criteria were generated through meetings, Delphi processes, analysis of electronic health record databases, and voting, followed by circulation to international professional societies, requesting peer review and endorsement (by 31 societies listed in the Acknowledgment).KEY FINDINGS FROM EVIDENCE SYNTHESIS: Limitations of previous definitions included an excessive focus on inflammation, the misleading model that sepsis follows a continuum through severe sepsis to shock, and inadequate specificity and sensitivity of the systemic inflammatory response syndrome (SIRS) criteria. Multiple definitions and terminologies are currently in use for sepsis, septic shock, and organ dysfunction, leading to discrepancies in reported incidence and observed mortality. The task force concluded the term severe sepsis was redundant.RECOMMENDATIONS: Sepsis should be defined as life-threatening organ dysfunction caused by a dysregulated host response to infection. For clinical operationalization, organ dysfunction can be represented by an increase in the Sequential [Sepsis-related] Organ Failure Assessment (SOFA) score of 2 points or more, which is associated with an in-hospital mortality greater than 10%. Septic shock should be defined as a subset of sepsis in which particularly profound circulatory, cellular, and metabolic abnormalities are associated with a greater risk of mortality than with sepsis alone. Patients with septic shock can be clinically identified by a vasopressor requirement to maintain a mean arterial pressure of 65 mm Hg or greater and serum lactate level greater than 2 mmol/L (>18 mg/dL) in the absence of hypovolemia. This combination is associated with hospital mortality rates greater than 40%. In out-of-hospital, emergency department, or general hospital ward settings, adult patients with suspected infection can be rapidly identified as being more likely to have poor outcomes typical of sepsis if they have at least 2 of the following clinical criteria that together constitute a new bedside clinical score termed quickSOFA (qSOFA): respiratory rate of 22/min or greater, altered mentation, or systolic blood pressure of 100 mm Hg or less.CONCLUSIONS AND RELEVANCE: These updated definitions and clinical criteria should replace previous definitions, offer greater consistency for epidemiologic studies and clinical trials, and facilitate earlier recognition and more timely management of patients with sepsis or at risk of developing sepsis.

5 pages; International audience; Although increasing attention is given to both the causes and consequences of variation in animal personality, the measurement of personality in captive or free-ranging individuals remains an issue. In particular, one important question concerns whether personality should be established from the existence of complex behavioral syndromes (a suite of correlated behavioral traits) or could be more easily deduced from a single variable. In that context, it has recently been suggested that handling stress, measured through breathing rate during handling, could be a good descriptor of personality, at least in passerine birds. The authors experimentally investigated to what extent handling stress was correlated with personality in female zebra finches (Taeniopygia guttata), as assessed from a suite of repeatable behavioral traits, including activity, exploratory behavior, neophobia, and reaction to startle. Although breathing rate was repeatable across individuals, it was not related to any behavioral trait, suggesting that it cannot be used to quickly predict personality, at least in zebra finches. Breathing rate during handling, in addition, was related to morphology, questioning the fact that breathing rate during handling reflects personality irrespective of individual state. The authors suggest that inference on global personality from a reduced number of traits should be performed with caution.

This article investigates the possibility of extracting gastric motility (GM) information from finger photoplethysmographic (PPG) signals non-invasively. Now-a-days measuring GM is a challenging task because of invasive and complicated clinical procedures involved. It is well-known that the PPG signal acquired from finger consists of information related to heart rate and respiratory rate. This thread is taken further and effort has been put here to find whether it is possible to extract GM information from finger PPG in an easier way and without discomfort to the patients. Finger PPG and GM (measured using Electrogastrogram, EGG) signals were acquired simultaneously at the rate of 100 Hz from eight healthy subjects for 30 min duration in fasting and postprandial states. In this study, we process the finger PPG signal and extract a slow wave that is analogous to actual EGG signal. To this end, we chose two advanced signal processing approaches: first, we perform discrete wavelet transform (DWT) to separate the different components, since PPG and EGG signals are non-stationary in nature. Second, in the frequency domain, we perform cross-spectral and coherence analysis using autoregressive (AR) spectral estimation method in order to compare the spectral details of recorded PPG and EGG signals. In DWT, a lower frequency oscillation (?0.05 Hz) called slow wave was extracted from PPG signal which looks similar to the slow wave of GM in both shape and frequency in the range (0-0.1953) Hz. Comparison of these two slow wave signals was done by normalized cross-correlation technique. Cross-correlation values are found to be high (range 0.68-0.82, SD 0.12, R = 1.0 indicates exact agreement, p

Motion sickness incidence (MSI) for vertical sinusoidal motion reaches a maximum at 0.167 Hz. Normal breathing frequency is close to this frequency. There is some evidence for synchronization of breathing with this stimulus frequency. If this enforced breathing takes place over a larger frequency range (0.05-0.8 Hz) and whether this contributes to the high MSI at 0.167 Hz was investigated. Sinusoidal motion (amplitude 0.3 g, frequencies 0.05, 0.1, 0.2, 0.4, and 0.8 Hz) was applied. Nausea with the MISC-scores and respiratory parameters, such as tidal volume, respiratory frequency, end-tidal CO 2 (PetCO2), and respiratory minute volume, were measured. Control conditions included rest and the hyperventilation provocation test. The nausea scores were highest at 0.2 Hz. With increasing frequencies the respiratory minute volume increased and the PetCO2 values decreased. The hyperventilation provocation test did not cause nausea. The main conclusion is that the high MSI at 0.167 Hz is not due to enforced breathing, since enforced breathing still increases with higher stimulus frequencies. © 2009 New York Academy of Sciences.

Objectives: Complaints of prolonged fatigue are considered as a major health problem, as it can affect daily functioning and may lead to work disability. To increase knowledge about the effectiveness of interventions focussing on fatigued patients, a study was designed to evaluate an established training programme for patients with prolonged fatigue. Materials and Methods: Eighteen patients who reported fatigue to be one of their major health complaints and who were suffering from functional impairments attended a training programme of six weeks, three times a week. The training consisted mainly of physical endurance training, relaxation therapy and breathing exercises in rest. At baseline, time- and frequency-domain measures of heart rate variability (HRV) and respiration rate measurements were recorded during rest and during recovery after bicycle exercise. Furthermore, fatigue complaints were assessed with the Checklist Individual Strength (CIS). These measurements were repeated at three weeks and six weeks from baseline. Results: After three weeks, HRV increased significantly in rest - SDNN, i.e. standard deviation of normal beat-to-beat intervals (p = 0.02), very low frequency (p = 0.04) and low frequency (p = 0.04) - and showed a positive trend in the remaining HRV components. No significant HRV changes during recovery were found. Respiration rate decreased significantly after six weeks during rest (from 11.8, SD = 4.65 to 8.1, SD = 2.57 b x min(-1)) and during recovery (from 15.1, SD = 4.90 to 10.4, SD = 2.97 b x min(-1)). In all patients, CIS scores decreased after six weeks training (from 106, SD = 13.3 to 78, SD = 21.8, p = 0.001). Conclusions: The results suggest that a six-week training programme has a beneficial effect on physiological and subjective parameters in patients with severe complaints of fatigue

Erythropoietin (EPO) is a hematopoietic factor, which is produced primarily by the adult kidney in response to tissue hypoxia. There is strong evidence that EPO may also be synthesized in the brain and act as a neuroprotector or neuromodulator in the central nervous system. The present study investigated the effect of centrally administered EPO on cardiovascular and respiratory parameters in anaesthetized rats. The animals were anaesthetized with ketamine (70 mg/kg) and xylazine (10 mg/kg) mixture. EPO at doses of 0.06, 0.12, 0.25 and 0.50 IU/5 μl or 0.9% saline as a control were injected intracerebroventricularly and blood pressure, heart rate, respiratory rate, tidal volume and minute ventilation were recorded. Following the administration of EPO, there was a significant increase in blood pressure, heart and respiratory rates, tidal volume and minute ventilation which were time and dose dependant. In order to investigate whether these effects of centrally injected EPO was caused by the diffusion of the drug to the periphery, the highest dose EPO (0.5 IU) in the present study, was injected intravenously but intravenously injected EPO showed no significant effect in these parameters. In conclusion, our findings showed that centrally injected erythropoietin caused pressor and tachycardic response, an increase in respiratory frequency and volume in anaesthetized rats. Moreover intravenous injection of the highest dose of EPO used in the study caused no effect suggesting a central mechanism of action for the agent. Hence, one can hypothesize that erythropoietin may play a role in the central regulation of cardiovascular and respiratory system as a neuromodulator or neuromediator.

Aim: To analyze the correlation of the Poincaré plot descriptors of RR intervals with standard measures of heart rate variability (HRV) and spontaneous baroreflex sensitivity (BRS). A physiological model of changing respiratory rates from 6 to 15 breaths/min provided a wide range of RR intervals for analysis. Material and methods: Beat-to-beat finger blood pressure, ECG, and respiratory curves were recorded noninvasively in 15 young healthy volunteers (19-25 years old; 7 females) breathing for 5 min at 4 different respiratory rates of 6, 9, 12, and 15 breaths/ min. Four descriptors of the Poincaré plot (SD1, SD2, S, and SD2/SD1), time and frequency domain HRV, and spontaneous BRS (cross-correlation method) were calculated for each 5-min recording. Results: The values of SD1 characterizing short-term HRV, SD2 describing long-term HRV, and S measuring total HRV were significantly correlated with BRS and time and frequency domain measures of short, long, and total HRV. The LF/ HF significantly correlated with SD2 and SD2/SD1 representing the balance between long- and short-term HRV. None of the Poincaré plot descriptors was correlated with the mean RR interval. The increased respiratory rate caused a significant reduction of BRS, measures of total and long-term HRV, and an increase of HF that peaked at 12 breaths/min. Conclusions: The descriptors of the Poincaré plot of RR intervals are significantly correlated with measures of BRS and time and frequency domain HRV, but not with heart rate. A faster respiratory rate reduces long-term HRV measures and temporarily increases HF.

OBJETIVO: o objetivo deste estudo foi determinar o efeito do posicionamento em prono na estabilidade cardiorrespiratória de prematuros, durante o desmame da ventilação mecânica e na evolução do desmame ventilatório. MÉTODO: de janeiro a dezembro de 1999, uma amostra de 42 prematuros, com peso de nascimento menor que 2.000 g, em ventilação mecânica na primeira semana de vida, foram, no início do desmame, randomizados em dois grupos: supino (n = 21), e prono (n = 21). A freqüência cardíaca, freqüência respiratória, saturação de oxigênio e parâmetros ventilatórios foram avaliados a cada hora. A duração e as complicações do desmame também foram avaliadas. RESULTADOS: em ambos os grupos, a média da idade gestacional foi de 29 semanas, a maioria dos pacientes foi de muito baixo peso ao nascimento, com síndrome do desconforto respiratório, e a mediana da duração do desmame foi de 2 dias. Não houve diferença entre os grupos na freqüência respiratória, na freqüência cardíaca e na saturação de oxigênio; entretanto, episódios de dessaturação foram mais freqüentes em supino (p = 0,009). No grupo prono, os parâmetros ventilatórios foram diminuídos mais rapidamente, e a necessidade de reintubação foi menos freqüente (4% x 33%). Não houve efeitos adversos da posição prona. CONCLUSÃO: aesses resultados sugerem que a posição prona é segura e benéfica durante o desmame da ventilação mecânica, e pode contribuir para o sucesso do desmame em prematuros. OBJECTIVE: the purpose of this study was to determine the effects of prone positioning on cardiorespiratory stability and weaning outcome of preterm infants during weaning from mechanical ventilation. METHOD: from January to December 1999, a sample of 42 preterm infants, with birthweight < 2,000 g, mechanically ventilated in the first week of life, were randomly divided, in the beginning of the weaning process, in two groups according to the position: supine position (n = 21) or prone position (n = 21). Heart rate, respiratory rate, transcutaneous oxygen saturation and ventilatory parameters were recorded every one hour. Length of the weaning process and complications were also assessed. RESULTS: in both groups the mean gestational age was 29 weeks, most of the patients presented very low birthweight and respiratory distress syndrome. The mean length of the weaning process was 2 days. There were no differences between the groups regarding respiratory rate, heart rate and transcutaneous oxygen saturation, however, oxygen desaturation episodes were more frequent in supine position (p = 0.009). Ventilatory parameters decreased faster and reintubation was less frequent in the prone group (4% versus 33%). No adverse effects of prone positioning were observed. CONCLUSION: these results suggest that prone position is a safe and beneficial procedure during the weaning from mechanical ventilation and may contribute to weaning success in preterm infants.