Local Pulse Wave Velocity estimation using Magnetic Plethysmograph
03 Jul 2013-Vol. 2013, pp 2287-2290
TL;DR: The design of a Compact Single element MPG (CS-MPG) sensor is presented and the functionality of the sensor is verified by phantom experiments, and the utility of this sensor for in-vivo measurements of PWV is demonstrated.
Abstract: Pulse Wave Velocity(PWV) is an established measure of arterial stiffness. We present a method of measuring local pulse wave velocity by the use of Magnetic Plethysmograph(MPG) sensors. The design of a Compact Single element MPG (CS-MPG) sensor is presented. The functionality of the sensor is verified by phantom experiments. The utility of this sensor for in-vivo measurements of PWV is also demonstrated. Further, a Dual-element MPG (D-MPG) for evaluation of local PWV is also presented. The error in measurement of PWV using this sensor is characterised experimentally and shown to be within acceptable limits. The ability of this dual element sensor to measure local PWV in-vivo is also demonstrated by trials on volunteers.
Citations
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TL;DR: A literature survey covering recent developments is presented in order to identify gaps in the literature regarding the calibration of pulse transit/arrival times to blood pressure, acquisition and processing of physiological signals and the design of fully integrated blood pressure measurement systems.
Abstract: Blood pressure monitoring based on pulse transit or arrival time has been the focus of much research in order to design ambulatory blood pressure monitors. The accuracy of these monitors is limited by several challenges, such as acquisition and processing of physiological signals as well as changes in vascular tone and the pre-ejection period. In this work, a literature survey covering recent developments is presented in order to identify gaps in the literature. The findings of the literature are classified according to three aspects. These are the calibration of pulse transit/arrival times to blood pressure, acquisition and processing of physiological signals and finally, the design of fully integrated blood pressure measurement systems. Alternative technologies as well as locations for the measurement of the pulse wave signal should be investigated in order to improve the accuracy during calibration. Furthermore, the integration and validation of monitoring systems needs to be improved in current ambulatory blood pressure monitors.
130 citations
TL;DR: This review is focused on heart rate measurement methods located on forearm and more specifically on the wrist, and the superposition of motion artefacts over the signal of interest is one of the largest drawbacks for these methods, when used out of laboratory conditions.
Abstract: When evaluating general health condition on a patient, heart rate is an essential indicator as it is directly representative of the cardiac system state. Continuous measurement methods of heart rate are required for ambulatory monitoring involved in preliminary diagnostic indicators of cardiac diseases or stroke. The growing number of recent developments in wearable devices is reflective of the increasing demand in wrist-worn activity trackers for fitness and health applications. Indeed, the wrist represents a convenient location in terms of form factor and acceptability for patients. While most commercially-available devices are based on optical methods for heart rate measurement, others methods were also developed, based on various physiological phenomena. This review is focused on heart rate measurement methods located on forearm and more specifically on the wrist. For each method, the physiological mechanism involved is described, and the associated transducers for bio-signal acquisition as well as practical developments and prototypes are presented. Methods are discussed on their advantages, limitations and their suitability for an ambulatory use. More specifically, the superposition of motion artefacts over the signal of interest is one of the largest drawbacks for these methods, when used out of laboratory conditions. As such, artefact reduction techniques proposed in the literature are also presented and discussed.
21 citations
Cites methods from "Local Pulse Wave Velocity estimatio..."
...pressure evaluation using PTT method [69, 70]....
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...[69] used an electromagnet made from a U-shaped magnetic core and an associated excitation coil....
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16 citations
03 Jul 2013
TL;DR: A simultaneous analysis system for blood pressure and flow using photoplethysmography and ultrasonic-measurement-integrated simulation is developed and confirmed by analysis of blood flow field in a carotid artery and corresponding wave intensity values.
Abstract: We developed a simultaneous analysis system for blood pressure and flow using photoplethysmography and ultrasonic-measurement-integrated simulation. The validity of the system was confirmed by analysis of blood flow field in a carotid artery and corresponding wave intensity (WI) values.
4 citations
13 May 2021
TL;DR: In this paper, the use of magnetic plethysmography as a noninvasive method of diagnostics of obstructive sleep apnea syndrome was considered, and a model of biotechnical system was designed and manufactured, taking into account the requirements for ergonomics and low cost, the software for data reception and visualization was developed, an algorithm for automatic registration of respiratory movements frequency was proposed, and the product was tested.
Abstract: Sleep breathing disorder is a pathological condition characterized by changes in respiratory parameters, which includes obstructive sleep apnea syndrome, which, according to modern research, is associated with cardiovascular diseases. The high prevalence of this pathology and the lack of practical possibility to perform an in-depth examination of all potentially needy people necessitates the development of new diagnostic principles. In this article, the method of magnetic plethysmography as a noninvasive method of diagnostics of obstructive sleep apnea syndrome was considered. The model of biotechnical system was designed and manufactured, taking into account the requirements for ergonomics and low cost, the software for data reception and visualization was developed, an algorithm for automatic registration of respiratory movements frequency was proposed, and the product was tested. According to the results of the research, the performance of the product was proven: the ability to register respiratory wave from the thoracic and abdominal surface, the selection of respiratory rate and heart rate, nighttime sleep monitoring, the ability to detect apnea episodes, the ability of the algorithm to automatically register respiratory rate. It is concluded that the biotechnical system can be used for screening patients with obstructive sleep apnea syndrome and needs further development.
References
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TL;DR: The finger blood pressure monitor measures blood pressure continuously and noninvasively by means of a technique described by J. Peňaz, and algorithms determine the unloaded artery size approximately every minute and automatically correct for changes possibly induced by smooth muscle contraction or relaxation.
Abstract: The finger blood pressure monitor measures blood pressure continuously and noninvasively by means of a technique described by J. Penaz. The size of the artery is measured when its internal pressure (arterial pressure) equals the external pressure. (At this point, transmural pressure equals zero and the arterial wall is said to be "unloaded.") This unloaded condition is maintained by continuous, automatic adjustments of external pressure on the artery, adjustments that are made simultaneously with and parallel to intraarterial pressure variations. The external pressure then constantly equals internal pressure (arterial blood pressure) and is reported by the monitor as values for systolic, mean, and diastolic pressure. A finger cuff with a built-in light source and detector is used to measure finger artery size, and an inflatable bladder is used to apply the external pressure to the artery. The monitor is microprocessor based; algorithms determine the unloaded artery size approximately every minute and automatically correct for changes possibly induced by smooth muscle contraction or relaxation, and a high-speed electropneumatic servo control system enables automatic calibration and adjustment.
139 citations
TL;DR: The reliability of Complior and PulsePen devices in estimating PWV is confirmed, while the SI determined by the PulseTrace device was found to be inappropriate as a surrogate of PWV.
Abstract: Arterial stiffness, estimated by pulse wave velocity (PWV), is an independent predictor of cardiovascular mortality and morbidity. However, the clinical applicability of these measurements and the elaboration of reference PWV values are difficult due to differences between the various devices used. In a population of 50 subjects aged 20-84 years, we compared PWV measurements with three frequently used devices: the Complior and the PulsePen, both of which determine aortic PWV as the delay between carotid and femoral pressure wave and the PulseTrace, which estimates the Stiffness Index (SI) by analyzing photoplethysmographic waves acquired on the fingertip. PWV was measured twice by each device. Coefficient of variation of PWV was 12.3, 12.4 and 14.5% for PulsePen, Complior and PulseTrace, respectively. These measurements were compared with the reference method, that is, a simultaneous acquisition of pressure waves using two tonometers. High correlation coefficients with the reference method were observed for PulsePen (r = 0.99) and Complior (r = 0.83), whereas for PulseTrace correlation with the reference method was much lower (r = 0.55). Upon Bland-Altman analysis, mean differences of values +/- 2s.d. versus the reference method were -0.15 +/- 0.62 m/s, 2.09 +/- 2.68 m/s and -1.12 +/- 4.92 m/s, for PulsePen, Complior and Pulse-Trace, respectively. This study confirms the reliability of Complior and PulsePen devices in estimating PWV, while the SI determined by the PulseTrace device was found to be inappropriate as a surrogate of PWV. The present results indicate the urgent need for evaluation and comparison of the different devices to standardize PWV measurements and establish reference values.
113 citations
TL;DR: It is shown that automatic processing of blood velocity signals obtained simultaneously from the left subclavian artery and abdominal aorta enables real-time computation of the time delay observed between the systolic upstroke (or foot) of sonograms from these arteries during the same heart beat.
Abstract: An on-line technique is described for measuring aortic compliance using a two-probe Doppler ultrasound method. It is shown that automatic processing of blood velocity signals obtained simultaneously from the left subclavian artery and abdominal aorta enables real-time computation of the time delay observed between the systolic upstroke (or foot) of sonograms from these arteries during the same heart beat. An average foot-to-foot transit time (obtained from a number of cardiac cycles) and the physical separation between the two ultrasonic transducers is used to calculate aortic compliance. Using the above method, the reproducibility of aortic compliance measurements was studied in 12 healthy volunteers over different time intervals. Four of these subjects were measured 7 times each at 10 min intervals whilst the remaining eight subjects were measured 9 times each at hourly intervals. This reproducibility study indicated a significant variation of aortic compliance (P less than 0.001) in the same person regardless of time period. The coefficient of variation ranged approximately between 5% and 18%.
30 citations
"Local Pulse Wave Velocity estimatio..." refers methods in this paper
...Designs based on oscillometry [7], Doppler ultrasound [8], applanation tonometry [9], MRI based imaging methods [10] were some of the earlier reported publications in PWV evaluation....
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TL;DR: The utility of a one-dimensional magnetic resonance sequence to rapidly and accurately measure wave velocity in vivo was evaluated and the MR method was validated in a compliant tube model.
Abstract: The utility of a one-dimensional magnetic resonance (MR) sequence to rapidly and accurately measure wave velocity in vivo was evaluated. Studies were conducted in the thoracic aortas of 20 healthy subjects of varying age, and the MR method was validated in a compliant tube model. Aortic wave velocity ranged from 3.8 to 9.7 m/sec and demonstrated a positive correlation with subjects' age. Peak blood velocity ranged from 47 to 125 cm/sec and exhibited a strong negative correlation with subjects' age.
28 citations
01 Nov 2010
TL;DR: In this paper, the authors presented their experience with the use of a giant magnetic resistance (GMR) based sensor for non-invasive detection of a bio-rhythm.
Abstract: The modulated magnetic signature based method has been recently suggested for non-invasive detection of blood pulse Here we present our experience with the use of a Giant Magnetic Resistance (GMR) based sensor for non-invasive detection of a bio-rhythm The influence of the biasing magnetic field on the amplitude and shape of the detected signal is presented Guidelines for the design of a bio-medical transducer using the principle are also provided The detected biorhythm is compared to other bio signals such as the blood flow velocity and arterial distension to gain insight into the physiological significance of the detected signal The analysis shows that the magnetic sensor provides a signal that is strongly correlated to the blood volume in the neighbourhood of the sensor Finally, the possibility of using the GMR based sensor for estimation of arterial compliance is investigated Simultaneous measurements performed at two different sites on the body show that this sensor can be used to measure arterial pulse wave velocity which is a clinically accepted measure of global arterial stiffness
17 citations
"Local Pulse Wave Velocity estimatio..." refers methods in this paper
...We had presented a permanent magnet and electromagnet based MPG (EM-MPG) [12] [13]....
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...We had previously introduced a novel MPG method for non-invasive detection of the blood flow pulse [13]....
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