Testing the reliability of commercially available smart devices to remotely assess the intensity of physical exertion during respiratory rehabilitation

Quantifying physiological vital sign differences in newborns from 34+0/7 weeks of gestation and establishment of vital sign reference ranges for the late preterm population

High-altitude hypoxia affects human physiology and primarily regulates the cardiovascular system by hypoxia-inducible factor and relative factors. This review introduces physiological changes in heart rate and blood oxygen saturation, commonly used monitoring techniques, and their limitations for the diagnosis of acute mountain sickness (AMS). Under acute hypoxia, peripheral oxygen saturation (SpO2) decreases, and heart rate increases; under subacute hypoxia, SpO2 rebound but remain below sea level baseline values, and heart rate gradually decreases; under long-term hypoxia heart rate returns to baseline values at sea level, but SpO2 remains below them. Tibetans exhibit lower heart rate than Han Chinese at identical altitudes, while Andeans show elevated heart rate versus lowlanders. SpO2 reductions persist in Tibetans/Andeans but approach lowlander levels in Ethiopians. Cerebral oxygen saturation is also used as a complementary indicator of blood oxygen saturation and could be applied to the monitoring of high-altitude hypoxic level, but there are fewer studies in this area. Current heart rate and blood oxygen saturation monitoring mainly relies on photoplethysmography (PPG). Researchers are aiming to use more objective monitoring of PPG to diagnose AMS, mainly focused on heart rate and blood oxygen saturation. While they have been identified as potential early warning indicators of AMS, significant individual variability leads to use them as definitive criteria for AMS diagnosis difficultly. Future research requires enhanced monitoring precision, exploring how individual genetic differences impact hypoxic responses, and developing personalized prevention and treatment strategies in order to provide new insights into high-altitude medicine.

Many COVID-19 survivors face various functional disorders. The purpose of this article was to determine the association between the degree of lung tissue damage and functional capacity of patients after COVID-19 pneumonia. Materials and methods. We examined patients (n = 264) aged 46–86 years that had suffered moderate or severe COVID-19 and undergone treatment for bilateral multisegmental pneumonia followed by rehabilitation. Functional capacity was measured using a walk test (at a normal pace to the first signs of exhaustion), taking into account heart rate (HR) and peripheral oxygen saturation (SpO2). The association between the degree of lung tissue damage and test results was analysed using simple and multiple regression analysis. Regression models included the following variables: walking distance, HR and SpO2 at rest and after the test, as well as demographic and clinical characteristics of patients. Results. At normal values of resting SpO2(96.3 ± 1.6 %) and resting HR (81.4 ± 12.1 bpm), fatigue occurred after walking the distance of 130.3 ± 96.4 m, SpO2 decreased to 93.8 ± 3.5 %, HR increased to 96.8 ± 14.0 bpm, the Borg score was 6 ± 3 points. Simple regression analysis showed a negative association of the degree of lung tissue damage with walking distance as well as with resting and after-test SpO2 and a positive association with resting HR. Multiple regression analysis indicated a tendency towards a greater decrease in walking distance and a larger increase in resting HR in men compared to women as well as an increase in walking distance and a reduction in resting HR in patients with chronic diabetes as the degree of lung tissue damage increased. Thus, greater degree of lung tissue damage is associated with decreased functional capacity in patients; however, the extent of this decrease may depend on their burdened history and sex.

Current monitoring systems available to track changes in the vital signs of patients (such as heart rate, respiratory rate or peripheral oxygen saturation) require contact with the subject. Most patients requiring regular monitoring find the probes difficult to wear over prolonged periods of time. Research in non-contact vital sign monitoring has recently expanded through the use of off-the-shelf video cameras; nevertheless, most of the current work in video-based non-contact vital sign monitoring has so far been performed over short time periods (typically up to a couple of minutes), under tightly controlled conditions with relatively still and healthy volunteer subjects. Using an off-the-shelf camera, we have been able to compute estimates of heart rate and respiratory rate, and also detect changes in peripheral oxygen saturation in a real hospital scenario, without interfering with regular patient care. Videos were recorded for 369.1 hours from 40 patients undergoing haemodialysis treatment in the Renal Unit of the Churchill Hospital in Oxford, UK. The mean absolute error between the heart rate estimates from the camera and the average from two reference pulse oximeters (positioned at the finger and earlobe respectively) was 2.8 beats per minute for over 65% of the time, which was comparable to the error between the two reference pulse oximeters. The mean absolute error between the respiratory rate estimates from the camera and the reference values (computed from the Electrocardiogram and a thoracic expansion sensor - chest belt) was 2.1 breaths per minute for over 69% of the time for which the reference signals were valid. By calibrating the camera data with the reference pulse oximeters, changes in peripheral oxygen saturation could also be tracked during time periods with minimal patient motion.

Background: Breast cancer survivors often experience cardiovascular and respiratory impairments due to treatment. This study evaluated the effects of a 12-week supervised aerobic exercise program on heart rate (HR) and peripheral oxygen saturation (SpO₂) in female breast cancer survivors. Methods: In a randomized controlled trial, 52 participants were allocated to either a 12-week supervised, moderate-intensity aerobic exercise group (n=27) or a usual care control group (n=25). Sessions were held thrice weekly in a community sports facility under professional supervision. HR and SpO₂ were recorded before and after each session at baseline, week 6, and week 12. Repeated-measures ANOVA and paired t-tests were used for statistical analysis (p<0.05). The study was ethically approved and registered with the Iranian Registry of Clinical Trials. Results: All participants completed the trial. By week 12, the intervention group demonstrated a significant increase in HR during exercise (from 77.7 ± 2.9 bpm pre-exercise to 127.3 ± 10.2 bpm post-exercise, p = 0.0001), while no significant change occurred in the control group (p = 0.21). Post-exercise SpO₂ was significantly higher in the intervention group compared to controls (97.7 ± 0.4% vs. 97.4 ± 0.4%, p = 0.008). Within-group analyses showed significant improvements from baseline in both HR and SpO₂ at week 12 (p < 0.001). High adherence (92.6%) and absence of adverse events confirmed the intervention’s safety. Conclusion: A 12-week supervised aerobic exercise program significantly improved cardiovascular and respiratory outcomes in breast cancer survivors, underscoring the value of structured exercise interventions in this population.

Cardiorespiratory instability may be undetected in monitored step-down unit patients. We explored whether using an integrated monitoring system that continuously amalgamates single noninvasive monitoring parameters (heart rate, respiratory rate, blood pressure, and peripheral oxygen saturation) into AN instability index value (INDEX) correlated with our single-parameter cardiorespiratory instability concern criteria, and whether nurse response to INDEX alert for patient attention was associated with instability reduction. Prospective, longitudinal evaluation in sequential 8-, 16-, and 8-wk phases (phase I, phase II, and phase III, respectively). A 24-bed trauma step-down unit in single urban tertiary care center. All monitored patients. Phase I: Patients received continuous single-channel monitoring (heart rate, respiratory rate, blood pressure, and peripheral oxygen saturation) and standard care; INDEX background was recorded but not displayed. Phase II: INDEX was background-recorded; staff was educated on use. Phase III: Staff used a clinical response algorithm for INDEX alerts. Any monitored parameters even transiently beyond local cardiorespiratory instability concern triggers (heart rate of <40 or >140 beats/min, respiratory rate of <8 or >36 breaths/min, systolic blood pressure of <80 or >200 mm Hg, diastolic blood pressure of >110 mm Hg, and peripheral oxygen saturation of <85%) defined INSTABILITYmin. INSTABILITYmin further judged as both persistent and serious defined INSTABILITYfull. The INDEX alert states were defined as INDEXmin and INDEXfull by using same classification. Phase I and phase III admissions (323 vs. 308) and monitoring (18,258 vs. 18,314 hrs) were similar. INDEXmin and INDEXfull correlated significantly with INSTABILITYmin and INSTABILITYfull (r = .713 and r = .815, respectively, p < .0001). INDEXmin occurred before INSTABILITYmin in 80% of cases (mean advance time 9.4 ± 9.2 mins). Phase I and phase III admissions were similarly likely to develop INSTABILITYmin (35% vs. 33%), but INSTABILITYmin duration/admission decreased from phase I to phase III (p = .018). Both INSTABILITYfull episodes/admission (p = .03) and INSTABILITYfull duration/admission (p = .05) decreased in phase III. The integrated monitoring system INDEX correlated significantly with cardiorespiratory instability concern criteria, usually occurred before overt instability, and when coupled with a nursing alert was associated with decreased cardiorespiratory instability concern criteria in step-down unit patients.

Effects of anodal transcranial direct current stimulation on intracranial compliance in the subacute phase of stroke

In animal studies it has been observed that the inhibitory neuromodulator adenosine is released into the cerebral interstitial space during hypoxic challenges. Adenosine's actions on the A1 adenosine receptor (A1AR) protect the brain from oxygen deprivation and overexertion through adjustments in cerebral blood flow, metabolism, and electric activity. Methods: Using 8-cyclopentyl-3-(3-[18F]fluoropropyl)-1-propylxanthine ([18F]CPFPX), a PET tracer for the A1AR, we tested the hypothesis that hypoxia-induced adenosine release reduces A1AR availability in the human brain. Furthermore, we investigated whether this response is associated with altered brain perfusion and psychomotor vigilance. Ten healthy volunteers completed a 110-min bolus-plus-constant-infusion [18F]CPFPX PET/MRI hybrid experiment including a 30-min interval of normobaric hypoxia with peripheral oxygen saturation between 70% and 75%. We obtained blood samples to calculate metabolite-corrected steady-state A1AR distribution volumes and measured gray matter brain perfusion via arterial spin labeling in high temporal resolution. A 3-min psychomotor vigilance test was conducted every 10 min, and heart rate and peripheral blood oxygen saturation were continuously measured. Results: In all 7 examined brain regions, hypoxia reduced A1AR availability significantly (e.g., frontal lobe, 13.5%; P = 0.0144) whereas gray matter brain perfusion increased (e.g., frontal lobe, 42.5%; P = 0.0007). Heart rate increased by 19% (P = 0.0039). Mean reaction speed decreased by 4.3% (P = 0.0021). Conclusion: Our study is the first, to our knowledge, to demonstrate that acute hypoxia, corresponding to a mean altitude of 5,500 m (18,000 ft), reduces A1AR availability in the human brain. The finding is consistent with hypoxia-induced cerebral adenosine release leading to increased A1AR occupancy.

Virtual Reality Glasses Reduce Patients' Anxiety During Emergency Surgical Procedures Under Local Anesthesia: A Randomized Controlled Clinical Study.

BackgroundThe acute physiological response to increased altitude includes increased cardiac output, via increased heart rate with no change in stroke volume, for improved oxygen delivery to tissues. An inability to adapt to decreased oxygen availability can result in hypoxemia and thus, hypoxia. Acclimatizing after extended exposure to the environment results in a return of cardiac output to baseline by maintaining an elevated heart rate with a reduction in stroke volume. Both training duration and intensity can impact the changes in heart rate and oxygen saturation. A significant fraction of climbers who attempt to summit Mt. Kilimanjaro (5895 m) are unsuccessful, usually due to inability to adapt to altitude. We wished to determine whether the physiological adjustments during the climb of Mt. Kilimanjaro were related to training before the climb, and whether the physiological adjustments of climbing guides differed from those of guided climbers.MethodsAll subjects provided informed consent. Ten guided climbers (6 male, 4 female, ages 21 to 69) and five guides (male, ages 24 to 31) completed an 8‐day climb of Mt. Kilimanjaro. Each guided climber completed a survey assessing their training regimen leading up to the climb. Guided climbers were classified into four categories based upon the intensities of their training regimens. Heart rate (HR) and peripheral oxygen saturation (SpO2) were measured by pulse oximeter. Each data point was measured twice to ensure accuracy. Data was collected from guided climbers and guides before beginning the climb, as well as each morning and evening while resting at camp from climbing day one to day six (summit night). Correlations were assessed with Spearman's rho, and differences between groups were assessed with the Mann Whitney U test.ResultsThere was a significant correlation between training intensity and overall change in heart rate from day one to day six (rs= 0.918, p&lt;.001) among the guided climbers, where those who trained harder before the climb increased their HR more during the climb. There was not a significant correlation between training intensity and decrease in oxygen saturation during the ascent (rs= □0.35, p&gt;0.3). There was a significant difference in the change in heart rate from day one to day six in the guides compared to the guided climbers (median ΔHR=+9.0 bpm for guides versus +20.5 bpm for guided climbers, U=0, p&lt;0.01). The change in oxygen saturation from day one to day six was not significantly different at the p&lt;.05 level between guides and guided climbers (median ΔSpO2 =−9.0% for guides and −11.5% for guided climbers, U=9.5, 0.05&lt;p&lt;0.10).ConclusionThe intensity of training prior to summit attempt impacts the changes in heart rate in Mt. Kilimanjaro climbers. Climbers who completed a higher intensity training program had a greater change in heart rate, allowing them to complete the climb with less difficulty than untrained individuals. There was a significant difference between the changes in heart rate as altitude increases between mostly unacclimatized individuals (guided climbers) and highly acclimatized individuals (guides).Support or Funding InformationThe David A. Plastino Scholars ProgramThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Introduction: The Kangaroo Mother Care (KMC) method is a significant neonatal alternative that ensures better quality humanized care for preterm and low birth weight newborns. Objective: To analyze the immediate physiological effects of the kangaroo position in critically ill newborns. Methods: Open clinical trial with parallel interventions, involving preterm (up to 28 days old) low or very low birth weight newborns (minimum weight of 1,250 grams) of both sexes, that were clinically stable and undergoing enteral nutrition. The degree of respiratory distress was assessed and quantified using the Silverman-Anderson scoring system. Heart rate and peripheral oxygen saturation were collected using a pulse oximeter. Respiratory rate was determined by auscultation for one minute. The newborns were submitted to the kangaroo position once only, for 90 minutes. Results: Participants were 30 newborns, 56.7% of which were girls. Comparison of the variables before and after application of the kangaroo position using the Wilcoxon test showed a statistically significant reduction in respiratory rate (p = 0.02) and Silverman-Anderson score (p &lt; 0.01). The remaining variables showed no significant differences: heart rate (p = 0.21), peripheral oxygen saturation (p = 0.26) and axillary temperature (p = 0.12). Conclusion: There was a decline in the respiratory rate and Silverman-Anderson score after application of the kangaroo position, while peripheral oxygen saturation, axillary temperature and heart rate remained stable.

Studies have indicated that natural environments have the potential to improve the relationship between a stressful life and psychological well-being and physical health. Forest therapy has recently received widespread attention as a novel solution for stress recovery and health promotion. Bamboo is an important forest type in many countries, especially in East and Southeast Asia and in African countries. Bamboo is widespread throughout southwestern China. Empirical field research on the physiological effects of bamboo forest therapy is currently lacking. To explore the benefits of bamboo forest therapy on the physiological responses of university students, 120 university volunteers between the ages of 19 and 24 participated in this study (60 males and 60 females) and were randomly divided into four groups of equal size (15 males and 15 females in each). Four sites were selected for the experiment, including two natural bamboo forests (YA and YB), a bamboo forest park (DJY), and an urban environment (CS). During the testing period, all participants were asked to view the landscape for 15 min in the morning and then walk in the testing area for 15 min in the afternoon. Blood pressure (BP), heart rate (HR), and peripheral oxygen saturation (SpO2) were measured as the physiological indexes, and the semantic differential method (SDM) questionnaire was completed for the environmental satisfaction evaluation. The SDM for the subjective environmental evaluation differed significantly among the university students; they obtained a better environmental experience, in terms of sensory perception, atmosphere, climate, place, and space, in the bamboo forest sites. The three-day bamboo forest therapy session improved the physiological well-being of university students. First, the blood pressure and heart rate of the university students decreased, and the SpO2 increased, after the three-day viewing and walking activities of the three-day bamboo forest therapy session. The viewing activities had a more pronounced effect on decreased heart rate in university students. Additionally, three-day bamboo forest therapy had a positive impact on decreased systolic blood pressure and heart rate in the university students, and it was significantly decreased in females, while peripheral oxygen saturation (SpO2) remained relatively low. Finally, compared with the urban site (CS), the bamboo forest sites effectively improved the university students’ physiological state of health, decreased their physical pressure, and stabilized their physiological indicators. These findings provide scientific evidence that a three-day bamboo forest therapy session can increase positive physiological responses. The potential for a longer-term effect on human physiological health requires further investigation.

Introduction: Exercise training by modulating blood pressure and heart rate have a protective role for middle-aged cardiac patients. Aim of this study was to compare the effect of eight weeks of aerobic and combined exercise on some hemodynamic indicators in middle-aged male patients undergoing coronary artery bypass graft surgery.&#x0D; Methods: In this clinical trial, a sample of 30 middle-aged men who underwent coronary artery surgery in 2023 were enrolled after meeting predetermined eligibility criteria and randomized for participation. They were divided into three aerobic (n=10), combined (n=10) and control (n=10) groups. The individuals of the 2 intervention groups performed selected aerobic and combined exercises (with an intensity of 55 - 75% of the maximum heart rate, for 60 minutes) for 8 weeks, 3 sessions per week. Blood pressure, heart rate and peripheral oxygen saturation (SpO2) were measured before and after the intervention. The parametric paired sample t-test, one-way ANOVA test and Tukey's Test were used to examine differences at a significance level of P ≤ 0.05.&#x0D; Results: The effect of aerobic exercises on systolic blood pressure (P=0.036), diastolic blood pressure (P=0.040) and heart rate (P=0.013) was significant and caused a decrease in these indicators, but the decrease in the combined group was not significant (P&gt;0.05). The intergroup effect difference was not significant (P&gt;0.05). In both aerobic (P=0.000) and combined (P=0.007) groups, the peripheral oxygen saturation has increased significantly and intergroup mean difference was significant (P=0.004).&#x0D; Conclusion: It seems that aerobic and combined exercises as a helpful intervention strategy to improve hemodynamic indicators, make the patient more adaptable to the conditions after coronary artery bypass graft surgery.

Hypoxia and hyperoxia can affect the acute psycho-physiological response to exercise. Recording various perceptual responses to exercise is of particular importance for investigating behavioral changes to physical activity, given that the perception of exercise-induced pain, discomfort or unpleasure, and a low level of exercise enjoyment are commonly associated with a low adherence to physical activity. Therefore, this study aimed to compare the acute perceptual and physiological responses to aerobic exercise under intermittent hypoxia-hyperoxia (IHHT), hypoxia-normoxia (IHT), and sustained normoxia (NOR) in young, recreational active, healthy males. Using a randomized, single-blinded, crossover design, 15 males (age: 24.5 ± 4.2 yrs) performed 40 min of submaximal constant-load cycling (at 60% peak oxygen uptake, 80 rpm) under IHHT (5 × 4 min hypoxia and hyperoxia), IHT (5 × 4 min hypoxia and normoxia), and NOR. Inspiratory fraction of oxygen during hypoxia and hyperoxia was set to 14% and 30%, respectively. Heart rate (HR), total hemoglobin (tHb) and muscle oxygen saturation (SmO2) of the right vastus lateralis muscle were continuously recorded during cycling. Participants' peripheral oxygen saturation (SpO2) and perceptual responses (i.e., perceived motor fatigue, effort perception, perceived physical strain, affective valence, arousal, motivation to exercise, and conflict to continue exercise) were surveyed prior, during (every 4 min), and after cycling. Prior to and after exercise, peripheral blood lactate concentration (BLC) was determined. Exercise enjoyment was ascertained after cycling. For statistical analysis, repeated measures analyses of variance were conducted. No differences in the acute perceptual responses were found between conditions (p ≥ 0.059, ηp 2 ≤ 0.18), while the physiological responses differed. Accordingly, SpO2 was higher during the hyperoxic periods during the IHHT compared to the normoxic periods during the IHT (p < 0.001, ηp 2 = 0.91). Moreover, HR (p = 0.005, ηp 2 = 0.33) and BLC (p = 0.033, ηp 2 = 0.28) were higher during IHT compared to NOR. No differences between conditions were found for changes in tHb (p = 0.684, ηp 2 = 0.03) and SmO2 (p = 0.093, ηp 2 = 0.16). IHT was associated with a higher physiological response and metabolic stress, while IHHT did not lead to an increase in HR and BLC compared to NOR. In addition, compared to IHT, IHHT seems to improve reoxygenation indicated by a higher SpO2 during the hyperoxic periods. However, there were no differences in perceptual responses and ratings of exercise enjoyment between conditions. These results suggest that replacing normoxic by hyperoxic reoxygenation-periods during submaximal constant-load cycling under intermittent hypoxia reduced the exercise-related physiological stress but had no effect on perceptual responses and perceived exercise enjoyment in young recreational active healthy males.

To evaluate the accuracy for 2 smartwatches with oximetry technology and optical wrist heart rate (HR) or single-lead Electrocardiography (ECG) technology (Fenix 5X Plus [GF5xp], Garmin Ltd and Apple Watch 6 [AppW6], Apple Inc, respectively) versus reference methods (ECG and transmittance pulse oximetry [TPO], respectively) in measuring HR and peripheral oxygen saturation of hemoglobin (SpO2) in cats. 10 male client-owned cats aged 8 to 12 months and weighing 3.2 to 4.5 kg. All cats that were presented for elective castration at the Atatürk University Animal Hospital between March 10 and April 15, 2022, were considered for enrollment. Monitoring of HR and SpO2 during anesthesia was performed with a 3-lead ECG and transmittance pulse oximetry, respectively, connected to a multiparameter monitor (reference methods) along with a GF5xp and a AppW6. Agreement between reference methods and the smartwatches were assessed by the Bland-Altman plot, in which the differences (%) between methods were plotted against their mean HR or SpO2 (reference method measurement - test device measurement) and the limits of agreement (mean ± 1.96 × SD). Compared with ECG measurements of HR, GF5xp had superior bias (-0.1%) and limit of agreement (LoA, 3.0 to -3.3%) versus those of the AppW6 (bias, 0.2%; LoA, 3.7 to -3.4%). Compared with TPO measurements of SpO2, AppW6 had superior bias (0.2%) and LoA (3.0% and -2.5%) versus those of the GF5xp (bias, -2.1%; LoA, 0.2 to -4.4%). Results indicated that the GF5xp and AppW6 exhibited high accuracy in evaluating HR and SpO2 in cats when compared with the reference methods. However, it should be noted that these comparisons were made in anesthetized patients without any systemic disease.