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Scientific Reports Sep 2021Lung diseases have high mortality and morbidity, with an important impact on quality of life. Hypoxemic patients are advised to use oxygen therapy to prolong their... (Comparative Study)
Comparative Study Observational Study
Lung diseases have high mortality and morbidity, with an important impact on quality of life. Hypoxemic patients are advised to use oxygen therapy to prolong their survival, but high oxygen saturation (SpO) levels can also have negative effects. Pulse oximeters are the most common way to assess oxygen levels and guide medical treatment. This study aims to assess whether wearable devices can provide precise SpO measurements when compared to commercial pulse oximeters. This is a cross-section study with 100 patients with chronic obstructive pulmonary disease and interstitial lung disease from an outpatient pneumology clinic. SpO and heart rate data were collected with an Apple Watch Series 6 (Apple) and compared to two commercial pulse oximeters. The Bland-Altman method and interclass correlation coefficient were used to compare their values. We observed strong positive correlations between the Apple Watch device and commercial oximeters when evaluating heart rate measurements (r = 0.995, p < 0.001) and oximetry measurements (r = 0.81, p < 0.001). There was no statistical difference in the evaluation of skin color, wrist circumference, presence of wrist hair, and enamel nail for SpO and heart rate measurements in Apple Watch or commercial oximeter devices (p > 0.05). Apple Watch 6 is a reliable way to obtain heart rate and SpO in patients with lung diseases in a controlled environment.
Topics: Aged; Cross-Sectional Studies; Female; Healthy Volunteers; Heart Rate; Humans; Lung Diseases, Interstitial; Male; Middle Aged; Oximetry; Oxygen Saturation; Pulmonary Disease, Chronic Obstructive; Reproducibility of Results; Wearable Electronic Devices; Wrist
PubMed: 34556765
DOI: 10.1038/s41598-021-98453-3 -
Scientific Reports Jan 2020Availability of daily continuous blood pressure (DCBP) has a strong impact to realization of healthy society. However, existing methods to obtain blood pressure of cuff... (Observational Study)
Observational Study
Availability of daily continuous blood pressure (DCBP) has a strong impact to realization of healthy society. However, existing methods to obtain blood pressure of cuff type and cuff-less types utilizing correlation with pulse waveform, pulse transit time or pulse rate; or computation of circulation model are not suitable to obtain DCBP. Here we implemented a method based on a simple circulatory system model using pulse rate measurement to overcome the limitations, and showed that it provides appropriate estimation of DCBP. The present model consists of a circulatory dynamic system model and an inverse model of a circulatory control system with input of pulse rate and six model parameters representing standard pulse rate, elasticity of systemic arteries, peripheral vascular resistance, and characteristics of resistance and stroke volume control. Validity of the DCBP estimation method was examined by preliminary experiment for one subject in four days and that for four subjects in one day. DCBP estimation was performed with 24-hour pulse rate measurement by a wearable device and sphygmomanometer measurement for parameter determination and verification. Mean absolute errors in systolic/diastolic pressures were appropriate ones for preliminary experiments with 9.4/6.4 mmHg in four days and 7.3/5.9 mmHg in five subjects.
Topics: Adult; Blood Pressure; Blood Pressure Monitoring, Ambulatory; Blood Pressure Monitors; Healthy Volunteers; Heart Rate; Humans; Male; Middle Aged; Models, Cardiovascular; Stroke Volume; Vascular Resistance; Wearable Electronic Devices; Young Adult
PubMed: 31996723
DOI: 10.1038/s41598-020-58367-y -
Sensors (Basel, Switzerland) Aug 2022The paper presents a wearable sensor for breath and pulse monitoring using an inertial sensor and episodic broadcast radio transmission. The data transmission control...
The paper presents a wearable sensor for breath and pulse monitoring using an inertial sensor and episodic broadcast radio transmission. The data transmission control algorithm applied allows for the transmission of additional information using the standard PDU format and, at the same time, goes beyond the Bluetooth teletransmission standard (BLE). The episodic broadcast transmission makes it possible to receive information from sensors without the need to create a dedicated radio link or a defined network structure. The radio transmission controlled by the occurrence of a specific event in the monitored signal is combined with the reference wire transmission. The signals from two different types of sensors and the simulated ECG signal are used to control the BLE transmission. The presented results of laboratory tests indicate the effectiveness of episodic data transmission in the BLE standard. The conducted analysis showed that the mean difference in pulse detection using the episodic transmission compared to the wire transmission is 0.038 s, which is about 4% of the mean duration of a single cycle, assuming that the average adult human pulse is 60 BPM.
Topics: Adult; Algorithms; Heart Rate; Humans; Monitoring, Physiologic; Respiration
PubMed: 36015777
DOI: 10.3390/s22166019 -
PloS One 2023Proteinoids are thermal proteins which swell into microspheres in aqueous solution. Ensembles of proteinoids produce electrical spiking activity similar to that of...
Proteinoids are thermal proteins which swell into microspheres in aqueous solution. Ensembles of proteinoids produce electrical spiking activity similar to that of neurons. We introduce a novel method for implementing logical gates in the ensembles of proteinoid microspheres using chronoamperometry. Chronoamperometry is a technique that involves applying a voltage pulse to proteinoid microspheres and measuring their current response. We have observed that proteinoids exhibit distinct current patterns that align with various logical outputs. We identify four types of logical gates: AND, OR, XOR, and NAND. These gates are determined by the current response of proteinoid microspheres. Additionally, we demonstrate that proteinoid microspheres have the ability to modify their current response over time, which is influenced by their previous exposure to voltage. This indicates that they possess a capacity for learning and are capable of adapting to their environment. Our research showcases the ability of proteinoid microspheres to perform logical operations and computations through their inherent electrical properties.
Topics: Microspheres; Heart Rate; Learning; Neurons
PubMed: 37721941
DOI: 10.1371/journal.pone.0289433 -
Journal of Clinical Hypertension... Jan 2019The relationship between resting pulse rate (PR) and the occurrence of hypertension and cardiovascular (CV) mortality has been described in the general population. Few... (Comparative Study)
Comparative Study
The relationship between resting pulse rate (PR) and the occurrence of hypertension and cardiovascular (CV) mortality has been described in the general population. Few studies have examined the relationship between ambulatory PR, ambulatory blood pressure (BP), and target organ damage (TOD) in patients with chronic kidney disease (CKD). A total of 1509 patients with CKD were recruited in our hospital. Ambulatory blood pressure monitoring (ABPM) over a 24-hours period was performed and referenced with clinical data in this cross-sectional study. TOD was measured by estimated glomerular filtration rate (eGFR), left ventricular hypertrophy (LVH), and carotid intima-media thickness (cIMT). Univariate and multivariate analyses were used to evaluate the relationship between PR, BP, and TOD. The percentage of male patients was 58.3% with a mean age of 44.6 ± 16.2 years. Nocturnal PR rather than 24-hours PR or daytime PR was an independent risk factor for clinical hypertension, 24-hours hypertension, BP dipper state, poor renal function, and LVH. In addition, the authors found that nighttime PR >74 beats/min (bpm) group was independently associated with clinical hypertension, 24-hours hypertension, day and night hypertension, nondipping BP, lower eGFR, and LVH when compared with nighttime PR <64 bpm group. Furthermore, 1:1 propensity score matching between PR ≤74 bpm group and PR >74 bpm group was performed. Multivariate analyses indicated nighttime PR >74 bpm remained independently associated with clinical hypertension, daytime and nighttime hypertension, and LVH. An increased nocturnal PR is associated with TOD, higher BP, and nondipping BP in patients with CKD.
Topics: Adult; Blood Pressure Monitoring, Ambulatory; Cardiovascular Diseases; Carotid Intima-Media Thickness; Circadian Rhythm; Cross-Sectional Studies; Female; Glomerular Filtration Rate; Heart Rate; Humans; Hypertension; Hypertrophy, Left Ventricular; Kidney; Male; Middle Aged; Prevalence; Renal Insufficiency, Chronic; Risk Factors
PubMed: 30597750
DOI: 10.1111/jch.13438 -
Journal of Hypertension Jan 2021When assessing arterial stiffness, heart rate (HR) and blood pressure (BP) are potential confounders. It appears that the HR/BP dependences of pulse wave velocity (PWV)...
OBJECTIVES
When assessing arterial stiffness, heart rate (HR) and blood pressure (BP) are potential confounders. It appears that the HR/BP dependences of pulse wave velocity (PWV) and distensibility are different, even though both assess arterial stiffness. This study aims to compare aortic PWV as measured using pulse transit time (PWVTT) and as calculated from distensibility (PWVdist) at the same measurement site and propose a solution to the disparity in dependences of PWVTT and PWVdist.
METHODS
Adult anaesthetized rats (n = 24) were randomly paced at HRs 300-500 bpm, at 50 bpm steps. At each step, aortic PWVTT (two pressure-tip catheters) and PWVdist (pressure-tip catheter and ultrasound wall-tracking; abdominal aorta) were measured simultaneously while BP was varied pharmacologically.
RESULTS
HR dependence of PWVdist paradoxically decreased at higher levels of BP. In addition, BP dependence of PWVdist was much larger than that of PWVTT. These discrepancies are explained in that standard PWVdist uses an approximate derivative of pressure to diameter, which overestimates PWV with increasing pulse pressure (PP). In vivo, PP decreases as HR increases, potentially causing a PWVdist decrease with HR. Estimating the full pressure-diameter curve for each HR corrected for this effect by enabling calculation of the true derivative at diastolic BP. This correction yielded a PWVdist that shows HR and BP dependences similar to those of PWVTT. As expected, BP dependence of all PWV metrics was much larger than HR dependence.
CONCLUSION
Measured and calculated PWV have different dependences on HR and BP. These differences are, at least in part, because of approximations made in using systolic and diastolic values to calculate distensibility.
Topics: Animals; Aorta; Blood Pressure; Heart Rate; Pulse Wave Analysis; Rats; Vascular Stiffness
PubMed: 32784350
DOI: 10.1097/HJH.0000000000002608 -
The Western Journal of Emergency... Oct 2020The American Heart Association Guidelines for Cardiopulmonary Resuscitation (CPR) recommend pulse checks of less than 10 seconds. We assessed the effect of video...
INTRODUCTION
The American Heart Association Guidelines for Cardiopulmonary Resuscitation (CPR) recommend pulse checks of less than 10 seconds. We assessed the effect of video review-based educational feedback on pulse check duration with and without point-of-care ultrasound (POCUS).
METHODS
Cameras recorded cases of CPR in the emergency department (ED). Investigators reviewed resuscitation videos for ultrasound use during pulse check, pulse check duration, and compression-fraction ratio. Investigators reviewed health records for patient outcomes. Providers received written feedback regarding pulse check duration and compression-fraction ratio. Researchers reviewed selected videos in multidisciplinary grand round presentations, with research team members facilitating discussion. These presentations highlighted strategies that include the following: limit on pulse check duration; emphasis on compressions; and use of "record, then review" method for pulse checks with POCUS. The primary endpoint was pulse check duration with and without POCUS.
RESULTS
Over 19 months, investigators reviewed 70 resuscitations with a total of 325 pulse checks. The mean pulse check duration was 11.5 ± 8.8 seconds (n = 224) and 13.8 ± 8.6 seconds (n = 101) without and with POCUS, respectively. POCUS pulse checks were significantly longer than those without POCUS (P = 0.001). Mean pulse check duration per three-month block decreased statistically significantly from study onset to the final study period (from 17.2 to 10 seconds [P<0.0001]) overall; decreased from 16.6 to 10.5 seconds (P<0.0001) without POCUS; and with POCUS from 19.8 to 9.88 seconds (P<0.0001) with POCUS. Pulse check times decreased significantly over the study period of educational interventions. The strongest effect size was found in POCUS pulse check duration (P = -0.3640, P = 0.002).
CONCLUSION
Consistent with previous studies, POCUS prolonged pulse checks. Educational interventions were associated with significantly decreased overall pulse-check duration, with an enhanced effect on pulse checks involving POCUS. Performance feedback and video review-based education can improve CPR by increasing chest compression-fraction ratio.
Topics: Aged; American Heart Association; Cardiopulmonary Resuscitation; Education, Medical, Graduate; Emergency Service, Hospital; Female; Heart Rate; Humans; Male; Middle Aged; Monitoring, Physiologic; Time Factors; Ultrasonography; United States; Video Recording
PubMed: 33207177
DOI: 10.5811/westjem.2020.8.47876 -
Investigative Ophthalmology & Visual... Apr 2020To study the effect of changing heart rate on the ocular pulse and the dynamic biomechanical behavior of the optic nerve head (ONH) using a comprehensive mathematical...
PURPOSE
To study the effect of changing heart rate on the ocular pulse and the dynamic biomechanical behavior of the optic nerve head (ONH) using a comprehensive mathematical model.
METHODS
In a finite element model of a healthy eye, a biphasic choroid consisted of a solid phase with connective tissues and a fluid phase with blood, and the lamina cribrosa (LC) was viscoelastic as characterized by a stress-relaxation test. We applied arterial pressures at 18 ocular entry sites (posterior ciliary arteries), and venous pressures at four exit sites (vortex veins). In the model, the heart rate was varied from 60 to 120 bpm (increment: 20 bpm). We assessed the ocular pulse amplitude (OPA), pulse volume, ONH deformations, and the dynamic modulus of the LC at different heart rates.
RESULTS
With an increasing heart rate, the OPA decreased by 0.04 mm Hg for every 10 bpm increase in heart rate. The ocular pulse volume decreased linearly by 0.13 µL for every 10 bpm increase in heart rate. The storage modulus and the loss modulus of the LC increased by 0.014 and 0.04 MPa, respectively, for every 10 bpm increase in heart rate.
CONCLUSIONS
In our model, the OPA, pulse volume, and ONH deformations decreased with an increasing heart rate, whereas the LC became stiffer. The effects of blood pressure/heart rate changes on ONH stiffening may be of interest for glaucoma pathology.
Topics: Animals; Biomechanical Phenomena; Finite Element Analysis; Glaucoma; Heart Rate; Humans; Intraocular Pressure; Models, Biological; Models, Theoretical; Optic Disk; Sensitivity and Specificity; Tonometry, Ocular
PubMed: 32315378
DOI: 10.1167/iovs.61.4.27 -
Computer Methods and Programs in... Jun 2022Consumer-level cameras have provided an advantage of designing cost-effective, non-contact physiological parameters estimation approaches which is not possible with gold... (Review)
Review
BACKGROUND
Consumer-level cameras have provided an advantage of designing cost-effective, non-contact physiological parameters estimation approaches which is not possible with gold standard estimation techniques. This encourages the development of non-contact estimation methods using camera technology. Therefore, this work aims to present a systematic review summarizing the currently existing face-based non-contact methods along with their performance.
METHODS
This review includes all heart rate (HR) and oxygen saturation (SpO2) studies published in journals and a few reputed conferences, which have compared the proposed estimation methods with one or more standard reference devices. The articles were collected from the following research databases: Institute of Electrical and Electronics Engineers (IEEE), PubMed, Web of Science (WoS), Science Direct, and Association of Computer Machinery (ACM) digital library. All database searches were completed on May 20, 2021. Each study was assessed using a finite set of identified factors for reporting bias.
RESULTS
Out of 332 identified studies, 32 studies were selected for the final review. Additionally, 18 studies were included by thoroughly checking these studies. 3 out of 50 (6%) studies were performed in clinical conditions, while the remaining studies were carried out on a healthy population. 42 out of 50 (84%) studies have estimated HR, while 5/50 (10%) studies have measured SpO only. The remaining three studies have estimated both parameters. The majority of the studies have used 1-3 min videos for estimation. Among the estimation methods, Deep Learning and Independent component analysis (ICA) were used by 11/42 (26.19%) and 9/42 (21.42%) studies, respectively. According to the Bland-Altman analysis, only 8/45 (17.77%) HR studies achieved the clinically accepted error limits whereas, for SpO, 4/5 (80%) studies have matched the industry standards (±3%).
DISCUSSION
Deep Learning and ICA have been predominantly used for HR estimations. Among deep learning estimation methods, convolutional neural networks have been employed till date due to their good generalization ability. Most non-contact HR estimation methods need significant improvements to implement these methods in a clinical environment. Furthermore, these methods need to be tested on the subjects suffering from any related disease. SpO estimation studies are challenging and need to be tested by conducting hypoxemic events. The authors would encourage reporting the detailed information about the study population, the use of longer videos, and appropriate performance metrics and testing under abnormal HR and SpO ranges for future estimation studies.
Topics: Face; Heart Rate; Humans; Oxygen Saturation
PubMed: 35390724
DOI: 10.1016/j.cmpb.2022.106771 -
Sensors (Basel, Switzerland) Oct 2022With the recent advancements in the field of wearable technologies, the opportunity to monitor stress continuously using different physiological variables has gained...
With the recent advancements in the field of wearable technologies, the opportunity to monitor stress continuously using different physiological variables has gained significant interest. The early detection of stress can help improve healthcare and minimizes the negative impact of long-term stress. This paper reports outcomes of a pilot study and associated stress-monitoring dataset, named the "Stress-Predict Dataset", created by collecting physiological signals from healthy subjects using wrist-worn watches with a photoplethysmogram (PPG) sensor. While wearing these watches, 35 healthy volunteers underwent a series of tasks (i.e., Stroop color test, Trier Social Stress Test and Hyperventilation Provocation Test), along with a rest period in-between each task. They also answered questionnaires designed to induce stress levels compatible with daily life. The changes in the blood volume pulse (BVP) and heart rate were recorded by the watch and were labelled as occurring during stress-inducing tasks or a rest period (no stress). Additionally, respiratory rate was estimated using the BVP signal. Statistical models and personalised adaptive reference ranges were used to determine the utility of the proposed stressors and the extracted variables (heart rate and respiratory rate). The analysis showed that the interview session was the most significant stress stimulus, causing a significant variation in heart rate of 27 (77%) participants and respiratory rate of 28 (80%) participants out of 35. The outcomes of this study contribute to the understanding the role of stressors and their association with physiological response and provide a dataset to help develop new wearable solutions for more reliable, valid, and sensitive physio-logical stress monitoring.
Topics: Humans; Pilot Projects; Wearable Electronic Devices; Heart Rate; Monitoring, Physiologic; Respiratory Rate; Photoplethysmography
PubMed: 36365837
DOI: 10.3390/s22218135