The Experts below are selected from a list of 240 Experts worldwide ranked by ideXlab platform
Alan Murray - One of the best experts on this subject based on the ideXlab platform.
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Variation of the Korotkoff Stethoscope Sounds During Blood Pressure Measurement: Analysis Using a Convolutional Neural Network
IEEE journal of biomedical and health informatics, 2017Co-Authors: Fan Pan, Alan Murray, Chengyu Liu, Dingchang ZhengAbstract:Korotkoff Sounds are known to change their characteristics during blood pressure (BP) measurement, resulting in some uncertainties for systolic and diastolic pressure (SBP and DBP) determinations. The aim of this study was to assess the variation of Korotkoff Sounds during BP measurement by examining all stethoscope Sounds associated with each heartbeat from above systole to below diastole during linear cuff deflation. Three repeat BP measurements were taken from 140 healthy subjects (age 21 to 73 years; 62 female and 78 male) by a trained observer, giving 420 measurements. During the BP measurements, the cuff pressure and stethoscope signals were simultaneously recorded digitally to a computer for subsequent analysis. Heart beats were identified from the oscillometric cuff pressure pulses. The presence of each beat was used to create a time window (1s, 2000 samples) centered on the oscillometric pulse peak for extracting beat-by-beat stethoscope Sounds. A time-frequency two-dimensional matrix was obtained for the stethoscope Sounds associated with each beat, and all beats between the manually determined SBPs and DBPs were labeled as ‘Korotkoff’. A convolutional neural network was then used to analyze consistency in sound patterns that were associated with Korotkoff Sounds. A 10-fold cross-validation strategy was applied to the stethoscope Sounds from all 140 subjects, with the data from ten groups of 14 subjects being analysed separately, allowing consistency to be evaluated between groups. Next, within-subject variation of the Korotkoff Sounds analysed from the three repeats was quantified, separately for each stethoscope sound beat. There was consistency between folds with no significant differences between groups of 14 subjects (P = 0.09 to P = 0.62). Our results showed that 80.7% beats at SBP and 69.5% at DBP were analysed as Korotkoff Sounds, with significant differences between adjacent beats at systole (13.1%, P = 0.001) and diastole (17.4%, P < 0.001). Results reached stability for SBP (97.8%, at 6th beats below SBP) and DBP (98.1%, at 6th beat above DBP) with no significant differences between adjacent beats (SBP P = 0.74; DBP P = 0.88). There were no significant differences at high cuff pressures, but at low pressures close to diastole there was a small difference (3.3%, P = 0.02). In addition, greater within subject variability was observed at SBP (21.4%) and DBP (28.9%), with a significant difference between both (P < 0.02). In conclusion, this study has demonstrated that Korotkoff Sounds can be consistently identified during the period below SBP and above DBP, but that at systole and diastole there can be substantial variations that are associated with high variation in the three repeat measurements in each subject.
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a method for extracting respiratory frequency during blood pressure measurement from oscillometric cuff pressure pulses and Korotkoff Sounds recorded during the measurement
International Conference of the IEEE Engineering in Medicine and Biology Society, 2016Co-Authors: Diliang Chen, Alan Murray, Fei Chen, Dingchang ZhengAbstract:Respiratory frequency is an important physiological feature commonly used to assess health. However, the current measurements involve dedicated devices which not only increase the medical cost but also make health monitoring inconvenient. Earlier studies have shown that respiratory frequency could be extracted from electrocardiography (ECG) signal, but little was done to assess the possibility of extracting respiratory frequency from oscillometric cuff pressure pulses (OscP) or Korotkoff Sounds (KorS), which are normally used for measuring blood pressure and more easily accessible than the ECG signal. This study presented a method to extract respiratory frequency from OscP and KorS during clinical blood pressure measurement. The method was evaluated with clinical data collected from 15 healthy participants, and its measurement accuracy was compared with a reference respiratory rate obtained with a magnetometer. Experimental results showed small non-significant mean absolute bias (0.019 Hz for OscP and 0.024 Hz for KorS) and high correlation (0.7 for both OscP and KorS) between the reference respiratory frequency and respiratory frequency extracted from OscP or KorS, indicating the high reliability of extracting respiratory frequency from OscP and KorS during normal blood pressure measurement.
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Respiratory modulation of oscillometric cuff pressure pulses and Korotkoff Sounds during clinical blood pressure measurement in healthy adults.
Biomedical engineering online, 2016Co-Authors: Diliang Chen, Alan Murray, Fei Chen, Dingchang ZhengAbstract:Background Accurate blood pressure (BP) measurement depends on the reliability of oscillometric cuff pressure pulses (OscP) and Korotkoff Sounds (KorS) for automated oscillometric and manual techniques. It has been widely accepted that respiration is one of the main factors affecting BP measurement. However, little is known about how respiration affects the signals from which BP measurement is obtained. The aim was to quantify the modulation effect of respiration on oscillometric pulses and KorS during clinical BP measurement.
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EMBC - A method for extracting respiratory frequency during blood pressure measurement, from oscillometric cuff pressure pulses and Korotkoff Sounds recorded during the measurement
Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Inte, 2016Co-Authors: Diliang Chen, Alan Murray, Fei Chen, Dingchang ZhengAbstract:Respiratory frequency is an important physiological feature commonly used to assess health. However, the current measurements involve dedicated devices which not only increase the medical cost but also make health monitoring inconvenient. Earlier studies have shown that respiratory frequency could be extracted from electrocardiography (ECG) signal, but little was done to assess the possibility of extracting respiratory frequency from oscillometric cuff pressure pulses (OscP) or Korotkoff Sounds (KorS), which are normally used for measuring blood pressure and more easily accessible than the ECG signal. This study presented a method to extract respiratory frequency from OscP and KorS during clinical blood pressure measurement. The method was evaluated with clinical data collected from 15 healthy participants, and its measurement accuracy was compared with a reference respiratory rate obtained with a magnetometer. Experimental results showed small non-significant mean absolute bias (0.019 Hz for OscP and 0.024 Hz for KorS) and high correlation (0.7 for both OscP and KorS) between the reference respiratory frequency and respiratory frequency extracted from OscP or KorS, indicating the high reliability of extracting respiratory frequency from OscP and KorS during normal blood pressure measurement.
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Effect of respiration on Korotkoff Sounds and oscillometric cuff pressure pulses during blood pressure measurement
Medical & Biological Engineering & Computing, 2014Co-Authors: Dingchang Zheng, Luigi Yuri Marco, Alan MurrayAbstract:Blood pressure (BP) measurement accuracy depends on consistent changes in Korotkoff Sounds (KorS) for manual measurement and oscillometric pulses for automated measurement, yet little is known about the direct effect of respiration on these physiological signals. The aim of this research was to quantitatively assess the modulation effect of respiration on Korotkoff Sounds and oscillometric pulses. Systolic and diastolic blood pressures were measured manually from 30 healthy subjects (age 41 ± 12 years). Three static cuff pressure conditions were studied for two respiratory rates. Cuff pressure [with oscillometric pulses (OscP)], ECG, chest motion respiration [respiration signal (Resp), from magnetometer] and Korotkoff Sounds (KorS, from digital stethoscope) were recorded twice for 20 s. The physiological data were evenly resampled. Respiratory frequency was calculated from Resp (f_R), OscP (f_O) and KorS (f_K) from peak spectral frequency. There was no statistically significant difference between f_R and f_O or f_K. Respiratory modulation was observed in all subjects. OscP amplitude modulation changed significantly between the two respiratory rates ( p
Jacques Clementy - One of the best experts on this subject based on the ideXlab platform.
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Ambulatory measurement of the timing of Korotkoff Sounds in a group of normal subjects: Influence of age and height
American Journal of Hypertension, 1999Co-Authors: Philippe Gosse, Véronique Jullien, P. Lemetayer, P. Jarnier, Jacques ClementyAbstract:Abstract Ambulatory measurement of timing of Korotkoff Sounds (QKD interval) gives an estimate of arterial distensibility derived from the velocity of the pulse wave over a vascular territory that includes the ascending aorta. The main advantages of the method are that it is entirely automatic, non–operator-dependent, and highly reproducible, and produces a measure independent of instantaneous blood pressure. This study of a group of 180 normal subjects aged between 10 and 78 years was designed to produce references values and to study the influence of height. The results confirmed the reduction with age of arterial distensibility in the whole population. However before the age of 30, QKD100-60 was positively correlated with height according to the relationship QKD100-60 = 0.73 height (cm) + 91, but not with age. This equation enables calculation of the theoretical value of QKD100-60 as a function of height for any patient to which the observed value can be expressed as a percentage. This effectively eliminates the influence of height, which reflects the length of the arterial segment under investigation.
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Prognostic Value of Ambulatory Measurement of the Timing of Korotkoff Sounds in Elderly Hypertensives: A Pilot Study
American Journal of Hypertension, 1997Co-Authors: Philippe Gosse, P. Lemetayer, Philippe Gasparoux, P Ansoborlo, Jacques ClementyAbstract:Abstract Alteration in the physical properties of the large arteries is probably an important contributory factor in morbidity and mortality in the elderly as well as in patients with hypertension or diabetes. We have developed a simple method based on the ambulatory measurement of the timing of Korotkoff Sounds (QKD interval), together with blood pressure, to assess these properties. We report its prognostic value in a retrospective survey of elderly hypertensives. We included in this study 134 hypertensive patients over 45 years of age with no cardiovascular complications, either receiving placebo or prior to treatment with antihypertensive medication and seen between January 1992 and July 1993. In June 1995, a survey was carried out to determine outcome by contacting the patients themselves and their family physicians. Data on outcome were obtained for 111 patients with a mean follow-up period of 30 ± 8 months. At least one cardiovascular complication was recorded during the follow-up period in 14 patients. From the Cox model, data obtained from QKD monitoring, namely the QKD 100-60 , was the best predictor of complications and remained significant ( P 100-60 below 187 msec was accompanied by a relative hazard of cardiovascular complications adjusted for age and mean 24 h BP of 7.3 (95% confidence interval: 2.9 to 11.7). The indices provided by the ambulatory measurement of QKD interval are significant predictors of cardiovascular complications independently of age and BP. This new method seems to add useful information to classic ambulatory blood pressure monitoring. However this will require confirmation in a large prospective study.
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Assessment of Arterial Distensibility by Monitoring the Timing of Korotkoff Sounds
American journal of hypertension, 1994Co-Authors: Philippe Gosse, Pascal Guillo, Gilles Ascher, Jacques ClementyAbstract:The timing of Korotkoff Sounds, blood pressure, and heart rate can now be monitored in the ambulatory patient: the QKD interval is the time between the onset of the depolarization on the electrocardiogram (Q) and detection of the last Korotkoff sound (K) at the level of brachial artery during cuff deflation, corresponding to diastolic blood pressure (D). Because this interval is inversely related to pulse wave velocity, this recently developed device enables evaluation of the influence of blood pressure on arterial rigidity, providing valuable information on the properties of the arteries. In this study, we examined the influence of hypertension and age on the above parameters and their correlations to left ventricular mass. QKD interval, blood pressure, and heart rate were monitored over a period of 24 h (four measurements/hour) in 33 normotensive and 70 untreated essential hypertensive patients. The slopes of the plots of QKD interval versus systolic and pulse pressure during the 24 h were calculated for each patient. The influence of age and hypertension on these slopes was tested by comparison of matched groups and multivariate analysis. Moreover the relationships between these parameters and echocardiographically assessed left ventricular mass were studied in 37 patients. We found a reduction in mean QKD interval with age and hypertension, reflecting the recognized higher pulse wave velocity in these patients. The slopes of the plots of QKD interval versus blood pressure were also lower in these patients, indicating the smaller influence of a change in blood pressure on pulse wave velocity in patients with stiffer arteries.(ABSTRACT TRUNCATED AT 250 WORDS)
Philippe Gosse - One of the best experts on this subject based on the ideXlab platform.
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Ambulatory measurement of the timing of Korotkoff Sounds in a group of normal subjects: Influence of age and height
American Journal of Hypertension, 1999Co-Authors: Philippe Gosse, Véronique Jullien, P. Lemetayer, P. Jarnier, Jacques ClementyAbstract:Abstract Ambulatory measurement of timing of Korotkoff Sounds (QKD interval) gives an estimate of arterial distensibility derived from the velocity of the pulse wave over a vascular territory that includes the ascending aorta. The main advantages of the method are that it is entirely automatic, non–operator-dependent, and highly reproducible, and produces a measure independent of instantaneous blood pressure. This study of a group of 180 normal subjects aged between 10 and 78 years was designed to produce references values and to study the influence of height. The results confirmed the reduction with age of arterial distensibility in the whole population. However before the age of 30, QKD100-60 was positively correlated with height according to the relationship QKD100-60 = 0.73 height (cm) + 91, but not with age. This equation enables calculation of the theoretical value of QKD100-60 as a function of height for any patient to which the observed value can be expressed as a percentage. This effectively eliminates the influence of height, which reflects the length of the arterial segment under investigation.
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Prognostic Value of Ambulatory Measurement of the Timing of Korotkoff Sounds in Elderly Hypertensives: A Pilot Study
American Journal of Hypertension, 1997Co-Authors: Philippe Gosse, P. Lemetayer, Philippe Gasparoux, P Ansoborlo, Jacques ClementyAbstract:Abstract Alteration in the physical properties of the large arteries is probably an important contributory factor in morbidity and mortality in the elderly as well as in patients with hypertension or diabetes. We have developed a simple method based on the ambulatory measurement of the timing of Korotkoff Sounds (QKD interval), together with blood pressure, to assess these properties. We report its prognostic value in a retrospective survey of elderly hypertensives. We included in this study 134 hypertensive patients over 45 years of age with no cardiovascular complications, either receiving placebo or prior to treatment with antihypertensive medication and seen between January 1992 and July 1993. In June 1995, a survey was carried out to determine outcome by contacting the patients themselves and their family physicians. Data on outcome were obtained for 111 patients with a mean follow-up period of 30 ± 8 months. At least one cardiovascular complication was recorded during the follow-up period in 14 patients. From the Cox model, data obtained from QKD monitoring, namely the QKD 100-60 , was the best predictor of complications and remained significant ( P 100-60 below 187 msec was accompanied by a relative hazard of cardiovascular complications adjusted for age and mean 24 h BP of 7.3 (95% confidence interval: 2.9 to 11.7). The indices provided by the ambulatory measurement of QKD interval are significant predictors of cardiovascular complications independently of age and BP. This new method seems to add useful information to classic ambulatory blood pressure monitoring. However this will require confirmation in a large prospective study.
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Prognostic value of ambulatory measurement of the timing of Korotkoff Sounds in elderly hypertensives: a pilot study.
American journal of hypertension, 1997Co-Authors: Philippe Gosse, P. Lemetayer, Philippe Gasparoux, P Ansoborlo, J. ClementyAbstract:Alteration in the physical properties of the large arteries is probably an important contributory factor in morbidity and mortality in the elderly as well as in patients with hypertension or diabetes. We have developed a simple method based on the ambulatory measurement of the timing of Korotkoff Sounds (QKD interval), together with blood pressure, to assess these properties. We report its prognostic value in a retrospective survey of elderly hypertensives. We included in this study 134 hypertensive patients over 45 years of age with no cardiovascular complications, either receiving placebo or prior to treatment with antihypertensive medication and seen between January 1992 and July 1993. In June 1995, a survey was carried out to determine outcome by contacting the patients themselves and their family physicians. Data on outcome were obtained for 111 patients with a mean follow-up period of 30 +/- 8 months. At least one cardiovascular complication was recorded during the follow-up period in 14 patients. From the Cox model, data obtained from QKD monitoring, namely the QKD(100-60), was the best predictor of complications and remained significant (P < .01) even after introduction of age, mean 24 h SBP, gender, and smoking into the model. A QKD(100-60) below 187 msec was accompanied by a relative hazard of cardiovascular complications adjusted for age and mean 24 h BP of 7.3 (95% confidence interval: 2.9 to 11.7). The indices provided by the ambulatory measurement of QKD interval are significant predictors of cardiovascular complications independently of age and BP. This new method seems to add useful information to classic ambulatory blood pressure monitoring. However this will require confirmation in a large prospective study.
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Assessment of Arterial Distensibility by Monitoring the Timing of Korotkoff Sounds
American journal of hypertension, 1994Co-Authors: Philippe Gosse, Pascal Guillo, Gilles Ascher, Jacques ClementyAbstract:The timing of Korotkoff Sounds, blood pressure, and heart rate can now be monitored in the ambulatory patient: the QKD interval is the time between the onset of the depolarization on the electrocardiogram (Q) and detection of the last Korotkoff sound (K) at the level of brachial artery during cuff deflation, corresponding to diastolic blood pressure (D). Because this interval is inversely related to pulse wave velocity, this recently developed device enables evaluation of the influence of blood pressure on arterial rigidity, providing valuable information on the properties of the arteries. In this study, we examined the influence of hypertension and age on the above parameters and their correlations to left ventricular mass. QKD interval, blood pressure, and heart rate were monitored over a period of 24 h (four measurements/hour) in 33 normotensive and 70 untreated essential hypertensive patients. The slopes of the plots of QKD interval versus systolic and pulse pressure during the 24 h were calculated for each patient. The influence of age and hypertension on these slopes was tested by comparison of matched groups and multivariate analysis. Moreover the relationships between these parameters and echocardiographically assessed left ventricular mass were studied in 37 patients. We found a reduction in mean QKD interval with age and hypertension, reflecting the recognized higher pulse wave velocity in these patients. The slopes of the plots of QKD interval versus blood pressure were also lower in these patients, indicating the smaller influence of a change in blood pressure on pulse wave velocity in patients with stiffer arteries.(ABSTRACT TRUNCATED AT 250 WORDS)
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Ambulatory measurement of Korotkoff Sounds timing (QKD interval) in a normal population
Archives des maladies du coeur et des vaisseaux, 1994Co-Authors: Philippe Gosse, C. Cailleau, J. C. Barthelemy, J. M. Chevalier, J. ClementyAbstract:Ambulatory monitoring of Korotkoff Sounds appearance time (QKD interval) was performed during 24 hours in 131 normal subjects (85 males, 46 females, aged 14-78 years, mean 36 +/- 15 years) with a new device (Diasys 200RK, Novacor-France). This device allows simultaneous measurements of blood pressure, heart rate and QKD interval at programmed intervals, every 15 minutes in this study. For each patient we calculated the average 24th QKD interval, the QKD interval for a systolic BP of 100 mmHg and a heart rate of 60 bt/min (QKD: 100-60), and the slope (S) of the variations of the QKD interval against systolic BP and pulse pressure (PP). Results are presented for each 10 years age group (mean +/- SD).
Dingchang Zheng - One of the best experts on this subject based on the ideXlab platform.
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Variation of the Korotkoff Stethoscope Sounds During Blood Pressure Measurement: Analysis Using a Convolutional Neural Network
IEEE journal of biomedical and health informatics, 2017Co-Authors: Fan Pan, Alan Murray, Chengyu Liu, Dingchang ZhengAbstract:Korotkoff Sounds are known to change their characteristics during blood pressure (BP) measurement, resulting in some uncertainties for systolic and diastolic pressure (SBP and DBP) determinations. The aim of this study was to assess the variation of Korotkoff Sounds during BP measurement by examining all stethoscope Sounds associated with each heartbeat from above systole to below diastole during linear cuff deflation. Three repeat BP measurements were taken from 140 healthy subjects (age 21 to 73 years; 62 female and 78 male) by a trained observer, giving 420 measurements. During the BP measurements, the cuff pressure and stethoscope signals were simultaneously recorded digitally to a computer for subsequent analysis. Heart beats were identified from the oscillometric cuff pressure pulses. The presence of each beat was used to create a time window (1s, 2000 samples) centered on the oscillometric pulse peak for extracting beat-by-beat stethoscope Sounds. A time-frequency two-dimensional matrix was obtained for the stethoscope Sounds associated with each beat, and all beats between the manually determined SBPs and DBPs were labeled as ‘Korotkoff’. A convolutional neural network was then used to analyze consistency in sound patterns that were associated with Korotkoff Sounds. A 10-fold cross-validation strategy was applied to the stethoscope Sounds from all 140 subjects, with the data from ten groups of 14 subjects being analysed separately, allowing consistency to be evaluated between groups. Next, within-subject variation of the Korotkoff Sounds analysed from the three repeats was quantified, separately for each stethoscope sound beat. There was consistency between folds with no significant differences between groups of 14 subjects (P = 0.09 to P = 0.62). Our results showed that 80.7% beats at SBP and 69.5% at DBP were analysed as Korotkoff Sounds, with significant differences between adjacent beats at systole (13.1%, P = 0.001) and diastole (17.4%, P < 0.001). Results reached stability for SBP (97.8%, at 6th beats below SBP) and DBP (98.1%, at 6th beat above DBP) with no significant differences between adjacent beats (SBP P = 0.74; DBP P = 0.88). There were no significant differences at high cuff pressures, but at low pressures close to diastole there was a small difference (3.3%, P = 0.02). In addition, greater within subject variability was observed at SBP (21.4%) and DBP (28.9%), with a significant difference between both (P < 0.02). In conclusion, this study has demonstrated that Korotkoff Sounds can be consistently identified during the period below SBP and above DBP, but that at systole and diastole there can be substantial variations that are associated with high variation in the three repeat measurements in each subject.
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a method for extracting respiratory frequency during blood pressure measurement from oscillometric cuff pressure pulses and Korotkoff Sounds recorded during the measurement
International Conference of the IEEE Engineering in Medicine and Biology Society, 2016Co-Authors: Diliang Chen, Alan Murray, Fei Chen, Dingchang ZhengAbstract:Respiratory frequency is an important physiological feature commonly used to assess health. However, the current measurements involve dedicated devices which not only increase the medical cost but also make health monitoring inconvenient. Earlier studies have shown that respiratory frequency could be extracted from electrocardiography (ECG) signal, but little was done to assess the possibility of extracting respiratory frequency from oscillometric cuff pressure pulses (OscP) or Korotkoff Sounds (KorS), which are normally used for measuring blood pressure and more easily accessible than the ECG signal. This study presented a method to extract respiratory frequency from OscP and KorS during clinical blood pressure measurement. The method was evaluated with clinical data collected from 15 healthy participants, and its measurement accuracy was compared with a reference respiratory rate obtained with a magnetometer. Experimental results showed small non-significant mean absolute bias (0.019 Hz for OscP and 0.024 Hz for KorS) and high correlation (0.7 for both OscP and KorS) between the reference respiratory frequency and respiratory frequency extracted from OscP or KorS, indicating the high reliability of extracting respiratory frequency from OscP and KorS during normal blood pressure measurement.
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Respiratory modulation of oscillometric cuff pressure pulses and Korotkoff Sounds during clinical blood pressure measurement in healthy adults.
Biomedical engineering online, 2016Co-Authors: Diliang Chen, Alan Murray, Fei Chen, Dingchang ZhengAbstract:Background Accurate blood pressure (BP) measurement depends on the reliability of oscillometric cuff pressure pulses (OscP) and Korotkoff Sounds (KorS) for automated oscillometric and manual techniques. It has been widely accepted that respiration is one of the main factors affecting BP measurement. However, little is known about how respiration affects the signals from which BP measurement is obtained. The aim was to quantify the modulation effect of respiration on oscillometric pulses and KorS during clinical BP measurement.
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EMBC - A method for extracting respiratory frequency during blood pressure measurement, from oscillometric cuff pressure pulses and Korotkoff Sounds recorded during the measurement
Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Inte, 2016Co-Authors: Diliang Chen, Alan Murray, Fei Chen, Dingchang ZhengAbstract:Respiratory frequency is an important physiological feature commonly used to assess health. However, the current measurements involve dedicated devices which not only increase the medical cost but also make health monitoring inconvenient. Earlier studies have shown that respiratory frequency could be extracted from electrocardiography (ECG) signal, but little was done to assess the possibility of extracting respiratory frequency from oscillometric cuff pressure pulses (OscP) or Korotkoff Sounds (KorS), which are normally used for measuring blood pressure and more easily accessible than the ECG signal. This study presented a method to extract respiratory frequency from OscP and KorS during clinical blood pressure measurement. The method was evaluated with clinical data collected from 15 healthy participants, and its measurement accuracy was compared with a reference respiratory rate obtained with a magnetometer. Experimental results showed small non-significant mean absolute bias (0.019 Hz for OscP and 0.024 Hz for KorS) and high correlation (0.7 for both OscP and KorS) between the reference respiratory frequency and respiratory frequency extracted from OscP or KorS, indicating the high reliability of extracting respiratory frequency from OscP and KorS during normal blood pressure measurement.
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Effect of respiration on Korotkoff Sounds and oscillometric cuff pressure pulses during blood pressure measurement
Medical & Biological Engineering & Computing, 2014Co-Authors: Dingchang Zheng, Luigi Yuri Marco, Alan MurrayAbstract:Blood pressure (BP) measurement accuracy depends on consistent changes in Korotkoff Sounds (KorS) for manual measurement and oscillometric pulses for automated measurement, yet little is known about the direct effect of respiration on these physiological signals. The aim of this research was to quantitatively assess the modulation effect of respiration on Korotkoff Sounds and oscillometric pulses. Systolic and diastolic blood pressures were measured manually from 30 healthy subjects (age 41 ± 12 years). Three static cuff pressure conditions were studied for two respiratory rates. Cuff pressure [with oscillometric pulses (OscP)], ECG, chest motion respiration [respiration signal (Resp), from magnetometer] and Korotkoff Sounds (KorS, from digital stethoscope) were recorded twice for 20 s. The physiological data were evenly resampled. Respiratory frequency was calculated from Resp (f_R), OscP (f_O) and KorS (f_K) from peak spectral frequency. There was no statistically significant difference between f_R and f_O or f_K. Respiratory modulation was observed in all subjects. OscP amplitude modulation changed significantly between the two respiratory rates ( p
Amir Benmira - One of the best experts on this subject based on the ideXlab platform.
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Systolic peak foot-to-apex time interval, a novel oscillometric technique for systolic blood pressure measurement
Journal of Hypertension, 2017Co-Authors: Amir Benmira, Antonia Perez-martin, Iris Schuster, Isabelle Aichoun, Sarah Coudray, Jérémy Laurent, Fethi Bereski-reguig, Michel DauzatAbstract:BACKGROUND: Noninvasive blood pressure (BP) measurement is essential for the study of human physiology but automatic oscillometric devices only estimate SBP and DBP using various, undisclosed algorithms, precluding standardization and interchangeability. We propose a novel approach by tracking, during pneumatic cuff deflation, the time interval from the foot to the apex of the systolic peak of the oscillometric signal, which reaches a maximum concomitant with the first Korotkoff sound. METHOD: In 145 study participants and patients (group 1), we measured the systolic brachial artery blood pressure by Korotkoff sound recording, conventional oscillometry, and our fully automated systolic peak foot-to-apex time interval (SFATI) technique. In 35 other patients (group 2), we compared SFATI with intra-arterial measurement. RESULTS: In group 1, the concordance correlation coefficient was 0.989 and 0.984 between SFATI and Korotkoff Sounds, 0.884 and 0.917 between oscillometry and Korotkoff Sounds, and 0.882 and 0.919 between SFATI and oscillometry, respectively, on the left and right arm. In group 2, it was 0.72 between SFATI and intra-arterial measurement, 0.67 between oscillometry and intra-arterial measurement, and 0.92 between SFATI and Korotkoff Sounds. In 40 study participants, the reproducibility study yielded a concordance coefficient of 0.95 for SFATI and 0.94 for Korotkoff Sounds. CONCLUSION: SFATI BP measurement shows an excellent concordance with the auscultatory technique, offering a major improvement over current oscillometric techniques and allowing standardization.
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An Ultrasound Look at Korotkoff Sounds: the role of pulse wave velocity and flow turbulence
Blood Pressure Monitoring, 2017Co-Authors: Amir Benmira, Antonia Perez-martin, Iris Schuster, Florent Veye, Jean Triboulet, Nicolas Berron, Isabelle Aichoun, Sarah Coudray, Jérémy Laurent, Fethi Bereksi-reguigAbstract:Aims : The aim of this study was to analyze the temporal relationships between pressure, flow, and Korotkoff Sounds, providing clues for their comprehensive interpretation. Materials and methods : When measuring blood pressure in a group of 23 volunteers, we used duplex Doppler ultrasonography to assess, under the arm-cuff, the brachial artery flow, diameter changes, and local pulse wave velocity (PWV), while recording Korotkoff Sounds 10 cm downstream together with cuff pressure and ECG.
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An ultrasound look at Korotkoff Sounds: the role of pulse wave velocity and flow turbulence.
Blood pressure monitoring, 2017Co-Authors: Amir Benmira, Antonia Perez-martin, Iris Schuster, Florent Veye, Jean Triboulet, Nicolas Berron, Isabelle Aichoun, Sarah Coudray, Jérémy Laurent, Fethi Bereksi-reguigAbstract:AimsThe aim of this study was to analyze the temporal relationships between pressure, flow, and Korotkoff Sounds, providing clues for their comprehensive interpretation.Materials and methodsWhen measuring blood pressure in a group of 23 volunteers, we used duplex Doppler ultrasonography to assess, u
