Video-based noncontact heart rate measurement using ear features

Background: Pulse oximetry is increasingly used in delivery rooms (DRs). Little is known about the newest generation of Nellcor oximeters, the Nellcor Oximax N-600x. We compared:□ HR measurements from Nellcor (HRNellcor) and Masimo oximeters (HRMasimo), against HR measured via three-lead electrocardiogram (ECG) (HRECG)□ Oxygen saturation (SpO2) measurements between the Nellcor (SpO2Nellcor) and Masimo (SpO2Masimo) oximetersMethods: Infants born via elective caesarean section were studied. ECG leads were placed on the infant's chest. Masimo and Nellcor oximeter sensors were randomly allocated to each foot. Measurements were collected for 10mins. Screens from the oximeters and ECG monitor were video recorded. Data was extracted by pausing the video every 2s to record HR and SpO2 measurements, and signal quality. The Bland-Altman method was used to determine agreement between HR measurements from the ECG and oximeters, and between SpO2 measurements from each oximeter.Results: We studied 44 infants of mean(SD) gestational age 38(1) weeks, birth weight 3246(527) grams, and median(IQR) Apgar scores of 9(9) at 1 and 5 minutes. Four infants received resuscitation. The numbers of paired observations were: ECG and Nellcor PO: 9422; ECG and Masimo PO: 8694; Nellcor and Masimo POs: 8382.The mean difference (± 2SD) between HRECG and HRNellcor was -0.8bpm (±11bpm); between HRECG and HRMasimo was 0.2bpm (±9bpm); and between HRMasimo and HRNellcor was -0.8bpm (±9bpm). The mean (±2SD) difference between SpO2Masimo and SpO2Nellcor was -3% (±15%).Conclusion: Both oximeters measure HR accurately, i.e. within 1bpm of HRECG. There was good agreement between HR and SpO2 measurements of the oximeters.

The current definition of sinus tachycardia is a heart rate >100 beats per minute (bpm).1 This limit was set arbitrarily when heart rate was not yet regarded as a risk factor for cardiovascular disease, probably with the main purpose of distinguishing between a disease state (fever, thyrotoxicosis, anemia, congestive heart failure, etc) and a normal condition. In recent years, interest has been aroused by the awareness that fast heart rate is a potent precursor of hypertension, atherosclerosis, and their sequelae.2 3 4 5 6 7 8 9 10 In addition, many leading epidemiological studies have shown that tachycardia is associated with an increased risk of death from cardiovascular and noncardiovascular causes. This relationship has been found in general populations,3 4 5 6 7 in elderly individuals,9 and in hypertensive cohorts.10 In all of these studies, the heart rate value above that in which a significant increase in risk was observed was below the 100 bpm threshold (Table 1⇓). Only in the study by Levy et al3 was tachycardia defined as a heart rate >99 bpm, but in that study the cutoff between normal and high heart rate was chosen arbitrarily, and the highest heart rate value measured during the examination was taken to define the subject’s heart rate. In all the other studies, the threshold level between normal and fast heart rate was between 79 and 90 bpm. View this table: Table 1. Heart Rate Values Above Which a Significant Increase in Risk Was Found: Data From 9 Epidemiological Studies The normalcy limits of a clinical variable can be established according to different criteria. For many parameters, such as most biochemical indexes, the 95% confidence interval is calculated to identify the upper normal limit of the variable. This statistical approach does not appear suitable for those clinical variables …

Recently, noncontact vital sign monitors have attracted attention because of issues related to the transmission of contagious diseases. We developed a real-time vital sign monitor using impulse-radio ultrawideband (IR-UWB) radar with embedded processors and software; we then evaluated its accuracy in measuring heart rate (HR) and respiratory rate (RR) and investigated the factors affecting the accuracy of the radar-based measurements. In 50 patients visiting a cardiology clinic, HR and RR were measured using IR-UWB radar simultaneously with electrocardiography and capnometry. All patients underwent HR and RR measurements in 2 postures—supine and sitting—for 2 min each. There was a high agreement between the RR measured using radar and capnometry (concordance correlation coefficient [CCC] 0.925 [0.919–0.926]; upper and lower limits of agreement [LOA], − 2.21 and 3.90 breaths/min). The HR measured using radar was also in close agreement with the value measured using electrocardiography (CCC 0.749 [0.738–0.760]; upper and lower LOA, − 12.78 and 15.04 beats/min). Linear mixed effect models showed that the sitting position and an HR < 70 bpm were associated with an increase in the absolute biases of the HR, whereas the sitting position and an RR < 18 breaths/min were associated with an increase in the absolute biases of the RR. The IR-UWB radar sensor with embedded processors and software can measure the RR and HR in real time with high precision. The sitting position and a low RR or HR were associated with the accuracy of RR and HR measurement, respectively, using IR-UWB radar.

Heart rate measurement is an important means of monitoring the physiological status of the human body. A non-contact heart rate measurement method is proposed by analyzing the change of pixels. Multi-filter and sub-region method are adopted to solve the problem of the complex heart rate signal extraction result. As the independence of the RGB color model, the green component signals can be taken from the mixed signals by using Fast ICA. The main peak noise is removed by the wavelet filtering and the band-pass filter, and the heart rate is obtained in the analysis of the energy spectrum by using the Fourier transform. The facial organs influence on the extraction of the heart rate signal is effectively reduced by dividing the face region, and the part of the face to best reflect the heart rate is further determined. The experimental results show that this method can be convenient and accurate to achieve the heart rate measurement, and the proposed division method of the most appropriate facial part to extract the heart rate enhances the application of the heart rate measurement.

We have shown that prominent changes in heart rate (HR) and blood pressure (BP) occur in dogs during classical defensive conditioning. These changes are usually analyzed as average HR and BP during control periods versus averages during conditional stimulus (CS) and unconditional stimulus (US) periods. A new method has been developed for evaluation of these functions, viz., analysis across many trials of successive beats beginning at onset of CS and working backward (control period) and forward (CS period). Nine awake dogs were continuously studied: six with HR and intra-arterial BP measurements and three with HR measurements only. A drop in HR occurs 1 to 2 beats after CS onset (often noted as a “dropped” beat on individual trials). In some dogs, on the third to fifth beat HR reaches its maximum during the CS period, thereafter falling slightly, but still above baseline; other dogs show progressively increasing HR throughout the whole CS period. At US onset (foreleg shock) HR usually rises rapidly to a peak greater than that at CS maximum. BP follows HR changes fairly closely, diastolic better than systolic. These results indicate that I) this method can reveal transients previously unsuspected, 2) a prominent initial sudden bradycardia followed by tachycardia commonly occurs in conditioning in dogs, 3) the latent period of prominent HR increase is usually quite short (1.3 to 1.6 secs.), and 4) BP follows HR directly during the early part of the CS.

Human bodily mechanisms and functions produce low-frequency vibrations. Our ability to perceive these vibrations is limited by our range of hearing. However, in-ear infrasonic hemodynography (IH) can measure low-frequency vibrations (<20 Hz) created by vital organs as an acoustic waveform. This is captured using a technology that can be embedded into wearable devices such as in-ear headphones. IH can acquire sound signals that travel within arteries, fluids, bones, and muscles in proximity to the ear canal, allowing for measurements of an individual’s unique audiome. We describe the heart rate and heart rhythm results obtained in time-series analysis of the in-ear IH data taken simultaneously with ECG recordings in two dedicated clinical studies. We demonstrate a high correlation (r = 0.99) between IH and ECG acquired interbeat interval and heart rate measurements and show that IH can continuously monitor physiological changes in heart rate induced by various breathing exercises. We also show that IH can differentiate between atrial fibrillation and sinus rhythm with performance similar to ECG. The results represent a demonstration of IH capabilities to deliver accurate heart rate and heart rhythm measurements comparable to ECG, in a wearable form factor. The development of IH shows promise for monitoring acoustic imprints of the human body that will enable new real-time applications in cardiovascular health that are continuous and noninvasive.

Developing technological issues provided that measure complex structure of team sports physiological loading during competition and trainings. During the last decade, limited numbers of researches reported about loading intensity and physiological response of junior girl basketball players during official competition. In this context, The aim of this study is determine of heart rate (HR) response during official competition in junior girl basketball players. 12 junior girl basketball players (age: 14.75±0.55 years, height: 168.48±5.3 cm, weight: 62.6±9.52 kg, predicted VO²max: 49.76±3.64 ml/kg/min) participated to this study. The HR measurements were taken official regional clubs league championship. Two days after followed up competition players performed the Shuttle Run Test (SRT) for determine maxHR levels. All HR measurement was taken by Polar Team2 (Finland). Frequency analyses were performed for the obtained data. Wilcoxon Rank Test was used for determined HR difference between halves. Friedman’s test was used for detected HR differences between periods. According to the analysis results, the maxHR levels obtained during SRT of the players were determined as 196,33 ± 10,04. The meanHR was determined 176,03±10,36 (89.66% of maxHR) in all competition. First half meanHR was 177,16±13,19 (90.23% of maxHR), second half meanHR was 175,00±11,56 (89.13% of maxHR), first period meanHR was 177,16±13,94 (90.00% of maxHR), second period meanHR was 176,87±12,10 (88.88% of maxHR), third period meanHR was 176,88±12,10 (90.08% of maxHR), fourth period meanHR was 179,40±10,71 (91.73% of maxHR). There were no difference found between halves and periods (p&gt;0.05). As a result of this study, HR response showed that intensity of junior girl basketball competition is approximately 89,66% of maxHR. This results showed that competition intensity is very high during all halves and periods. The determination of the official competition intensity of junior girl basketball players can provide important knowledge to coaches that young players have improved their sporting performance. ÖzetMüsabaka ve antrenmanlar sırasında takım sporunun fizyolojik yükünün karmaşık yapısını ölçen teknolojik gelişmeler sağlanmıştır. Son on yılda, resmi müsabaka sırasında yıldız kız basketbolcuların fizyolojik tepkileri ve yüklenme yoğunluğu ile ilgili sınırlı sayıda araştırma rapor edilmiştir. Bu bağlamda, bu çalışmanın amacı, yıldız kız basketbolcuların resmi müsabaka sırasında kalp atım hızı (KAH) yanıtlarını belirlemektir. Çalışmaya 12 yıldız kız basketbolcu (yaş: 14,75±0,55, boy: 168,48±5,30, vücut ağırlığı: 62,6±9,52, tahmini VO²maks: 49,76±3,64 ml/kg/dk) katıldı. KAH ölçümleri resmi bölgesel klüpler lig şampiyonasında alındı. Maçtan iki gün sonra KAH seviyelerini belirlemek için 20 m. Mekik Koşusu Testi (20MKT) uygulandı. Basketbolcuların müsabaka ve 20MKT sırasında kalp atım hızları Polar Team2 (Finland) sistem ile ölçüldü. Elde edilen veriler için frekans analizi uygulandı. Yarılar arasındaki KAH farkı için Wilcoxon Rank Testi kullanıldı. Periodlar arasındaki KAH farkları Friedman’s Testi ile tespit edildi. Analiz sonuçlarına göre, oyuncuların 20MKT sırasında elde edilen maksKAH değerleri 196,33±10.04 olarak tespit edildi. Basketbolcuların tüm müsabaka ortKAH 175,93±10,19 (maks KAH’ın %89.66). İlk yarı ortKAH 177,16±13,19 (maksKAH'ın %90.23), ikinci yarı ortHR 175,00±11,56 (maksKAH'ın 89.13), ilk period ortHR 177,16±13,94 (maksKAH'ın %90.00), ikinci period ortHR 176,87 ± 12,10 (maksKAH'ın %88.88), üçüncü period ortHR 176,88±12,10 (maksKAH'ın %90.08), dördüncü period ortHR 179,40±10,71 (maksKAH'ın %91.73) olarak tespit edildi. Periyotlar ve yarılar arasında ortKAH bakımından anlamlı fark bulunmamıştır (p&gt;0.05). Bu çalışmanın bir sonucu olarak, yıldız kız basketbol müsabakasında KAH cevaplarının maxKAH'ın yaklaşık %89,66 şiddetinde olduğu görüldü. Bu sonuçlar, müsabaka yoğunluğunun tüm yarılar ve periyotlar için çok yüksek olduğunu göstermektedir. Yıldız oyuncuların resmi müsabaka yoğunluğunun belirlenmesi, genç oyuncuların spor performansını geliştirdiklerine dair antrenörlere önemli bilgi sağlayabilir.

Daily heart rate (HR) is usually higher among HIV+ compared with HIV- adults, a possible aspect of chronotropic incompetence (CI) in this population. Low cardiorespiratory fitness (CRF) and metabolic syndrome (MetSyn) are prevalent among HIV+ adults, possibly influencing CI. However, information regarding 24-hr HR as an index of CI, and its association with CRF and MetSyn in this population is nonexistent. PURPOSE: To describe the association between CRF, MetSyn, and daily HR in a group of HIV+ and HIV- Hispanic adults in Puerto Rico. METHODS: Eighty-Nine adults (59-HIV+ and 30 HIV-) completed measurements of CRF (VO2 peak), 24-hr blood pressure and HR, and metabolic syndrome (fasting glucose and lipid profile, resting BP, waist circumference). T-tests were used to detect differences between groups, and correlation analyses to evaluate associations between variables. RESULTS: The proportion of low CRF based on age and sex, and MetSyn was not different between HIV+ and HIV-participants (56 vs. 40%; and 53 vs. 37%; P=0.2, respectively). However, 24-hr HR, daytime HR, and night-time HR were all significantly higher in HIV+ compared with HIV- participants (78.3±9.4 vs. 67.4±8.4, 81.9±9.9 vs. 69.7±8.6, 70.7±9.4 vs. 62.7±9.0 bpm, respectively, P<0.05 for all). VO2 peak was inversely correlated with 24-hr HR, daytime HR, and night-time HR in both groups (ρ= -0.40, -0.36, -0.49, P<0.05 for all). Considering CRF classification in each group, all HR measures were significantly lower among those with high CRF vs. low CRF regardless of HIV status (HIV+: 24-hr HR by CRF: low= 81.1±8.2 vs. high= 74.8±9.7 bpm, P=0.009; daytime HR: low=85.0±8.7 vs. high=78.0±10.2 bpm, P=0.006; night-time HR: low=72.8±8.7 vs. high=68.0±9.8 bpm, P=0.02) (HIV-: 24-hr HR by CRF: low= 72.1±4.4 vs. high= 64.2±9. bpm, P=0.009; daytime HR: low=74.1±4.9 vs. high=66.8±9.4 bpm, P=0.02; night-time HR: low=67.8±6.1 vs. high=59.2±9.1 bpm, P=0.008). No HR differences were observed by MetSyn in the HIV+ group, but HR measures in the HIV- group were lower in those without MetSyn. CONCLUSION: These results suggest that CRF but not MetSyn, influence daily HR in HIV+ participants, with potential impact on CI correction. Intervention studies must be conducted to confirm these results. Supported by: NIH/CTSA KL2-RR024151, NIH/NIMHHD 8U54MD 007587-03.

Non-invasive heart rate measurement is essential in medical and sport sciences. Typically, the first stage of heart rate measurements is obtained from non-invasive sensors. In this paper, the data from video sequences of a subject cycling are processed using short-time Fourier transform (STFT) to indicate the heart rate of the subject. The choice of using STFT is its ability to provide more accurately localized temporal and frequency information, especially for the rapidly changing heart rate pattern during the exercise routine. Experimental results show the proposed method can provide an acceptable result and the root mean square error is less than 2.5 beats per minute (BPM) for heart rate variations between 80 BPM and 130 BPM.

Heart Rate (HR) measurement using wrist-worn devices suffers from noises owing to body movement. Even though many researchers have proposed sophisticated methods for the compensation of noisy measurement, such factors cause corruption of sensor data itself, leading to difficulty in compensation. In this paper, we design a method for the reliability estimation of HR measurement. The key idea is that the change of HR correlates with the magnitude of body movement and current HR. For modeling the correlation, we construct a modified Kalman filter that estimates the displacement of HR from the statistical data of HR measured by a chest-worn device and the variance of acceleration measured by a wrist-worn device. Then, we define the reliability of HR measurement as the absolute error between the output of the modified Kalman filter and the HR measured by a wrist-worn device. For evaluation, we compare our method with a conventional outlier removal and smoothing after compensation using one of the state-of-the-art methods based on deep learning. As a result, our method successfully removes 18.9% of the measurement with low reliability while achieving the mean absolute error of 6.25bpm, superior to the conventional methods.

Indirect/noninvasive blood pressure, heart rate and central venous pressure are frequently monitored hemodynamic parameters in postoperative cardiac surgery patients. No previous studies have explored the effect of lateral position on these variables in this population. To determine differences in (1) blood pressure, central venous pressure, or heart rate measurements among postoperative cardiac surgery patients due to position (supine, 45 degrees right lateral, and 45 degrees left lateral), (2) responses to position between patients having cardiac surgery in which the myocardium was opened (valvular replacement) and those in which it was not (coronary artery bypass graft), and (3) responses to position between cardiac surgery patients having preoperatively diagnosed lung disease and those without lung disease. Phlebostatic axis in lateral positions was determined by echocardiography and geometric diagrams prior to the initiation of data collection. Postoperative cardiac surgery patients (N = 120) were studied in the three positions in random sequences. In each position, simultaneous blood pressure measurements were obtained from each arm, and central venous pressure and heart rate were recorded. Statistically significant differences were found in response to position in systolic and diastolic blood pressure, central venous pressure, and heart rate. Certain positions produced greater changes in selected variables, both in the total group and within specific subgroups. No differences were found between coronary artery bypass graft and valve (closed or opened myocardium) subgroups or between subgroups with and without lung disease. Lateral positioning of postoperative cardiac surgery patients appears to cause no detrimental effects on indirect/noninvasive blood pressure or heart rate measurements. However, significant differences in central venous pressure may occur and supine positioning for determination of central venous pressure is recommended.

Carbon monoxide (CO) is suspected of playing a major role in cigarette smoke-induced cardiovascular diseases. Hypertension is one of the common chronic cardiovascular diseases that lead to heart attacks, strokes, chronic heart failure, and chronic renal failure. We aimed to investigate the immediate effects of passive smoking on blood pressure and heart rate during and after exposure in healthy females. In addition, we examined that whether carboxyhemoglobin (COHb) levels were correlated with heart rate and blood pressure measurements. Thirty healthy nonsmoker female volunteers (mean age: 26±5 years) were prospectively enrolled in the study. Systolic and diastolic blood pressure and heart rate were obtained at baseline, 5th, 10th, 15th, 30th minute of exposure and at 5th, 15th, and 30th minute after exposure. Blood samples for measuring COHb were taken at baseline and after spending 30 min in the smoking room from all volunteers. Difference between baseline and second measurements of COHb were described as ΔCOHb. Mean COHb level was significantly higher at the end of exposure when compared with baseline values (COHb 0.5±0.1 vs. 1.8±0.4%, P<0.05). Heart rate and systolic blood pressure measurements at 15th and 30th minute of exposure were higher than at baseline and 5th minute of exposure (88±3.2 and 90±3.7 vs. 76±3.9 and 78±4.5 beats/min, P<0.05; 135±1.1 and 136±4.0 vs. 113±5.7 and 115±3.5 mmHg, P<0.05). They elevated significantly at the same time interval. Diastolic blood pressure was significantly increased at 30th minute of exposure when compared with earlier measurements (90±5.1 vs. 74±2.2, 72±3.2 vs. 71±4.5 mmHg, P<0.05). Heart rate and systolic blood pressure decreased notably at 15th minute and returned to baseline values at 30th minute after exposure (80±1.2 and 76±3.2 vs. 88±4.5 beats/min, P<0.05; 120±4.4 and 115±1.9 vs. 135±2.2 mmHg, P<0.05). Diastolic blood pressure decreased significantly at 30th minute and returned to baseline values at 60th minute after exposure (75±3.6 and 70±2.5 vs. 89±4.3 mmHg, P<0.05). Heart rate and diastolic blood pressure measurements were moderately correlated and systolic blood pressure measurements were closely correlated with ΔCOHb values at the end of the exposure. Our results suggested that passive smoking has remarkable acute effect on heart rate and blood pressure in young healthy females. Beside this, we found that ΔCOHb level is closely correlated with systolic blood pressure and moderately correlated with heart rate and diastolic blood pressure measurements.

In visual search tasks snake or spider fearful participants showed shorter reaction times (RTs) to respond to their feared animal (e.g., snake) than to the nonfeared animal (i.e., spider) (Öhman, Flykt, & Esteves, 2001). Here, we used this paradigm with heart rate (HR), RTs, and event-related potential (ERP) measures, to investigate the nature of the responses to the feared animal, a nonfeared (but fear-relevant) animal, and fear-irrelevant target stimuli with snake fearful, spider fearful, and nonfearful participants. Fearful participants showed shorter RTs and evoked larger amplitudes on a late positive potential (LPP; 500–700 ms) for their feared compared to the nonfeared and the fear-irrelevant targets. No relevant significant differences were found on early ERP components and HR measures. These findings do not support an involvement of early information processing in the detection of the feared animal in fearful participants, they favour instead a more elaborated analysis of these complex stimuli to achieve the detection.

ObjectiveThis study aimed at assessing the effectiveness of cognitive‐behavioural therapy (CBT) integrated with psychoeducation in a group of hypertensive patients with clinically significant psychopathological symptoms.MethodsOne hundred hypertensive patients completed the Symptom Checklist‐90‐Revised. Of them, 17 scored above the clinical range (cut‐off = 0.75) on the Global Severity Index and were included in the study. Psychological distress was assessed again after the intervention (T1) and 6 months after the end of treatment (T2). In addition, the cortisol dosage and the heart rate (HR) measurement were collected at both T0 and T2. Then, mediation analyses were carried out to calculate whether psychopathological distress might predict HR through elevated serum cortisol levels, at both T0 and T2.ResultsThe psychological intervention (CBT integrated with psychoeducation) reduced most of the psychopathological symptoms (anxiety, depression, somatisations, obsessions and compulsions, hostility, interpersonal sensitivity and paranoid ideation) but not cortisol dosage and HR measurement. However, psychological distress indirectly predicted HR via cortisol at T0 but not at T2.ConclusionThese results suggest and encourage the replicability of data in larger sample sizes and the comparison with a control group. Nevertheless, these results highlight a need for a multidimensional assessment of disorders affecting the mental and physical spheres of patients to support their overall well‐being.

A psychophysiological investigation of the effects of driving longer-combination vehicles