Measurement Of Arterial Pulse Research Articles

Evaluation of primary hemodynamic parameters using in-house developed flexible microstructured pressure sensor

Noninvasive measurement of arterial pulse provides information about the heart condition through the evaluation of primary hemodynamic parameters such as blood pressure (BP), pulse rate (PR), and pulse regularity. Moreover, BP is one of the most important biomarkers of cardiovascular disease, mainly hypertension. To prevent this, accurate measurement of BP becomes necessary. Currently, flexible pressure sensors have drawn a lot of interest due to their prospective applications in wearable devices for healthcare monitoring. We have collected the human oscillometric pulse by a polymer-based flexible capacitive pressure sensor and calculated the BP as well as PR using the maximum amplitude algorithm. The results are compared with a pre-calibrated oscillometric BP monitor available in the market. Based on the error criteria, the device followed the universal standard. In addition, the flexibility and high accuracy of the device result in the assessment of the possible medical applications, including abnormal pulse rates such as tachycardia or bradycardia and irregular heart rhythm such as cardiac arrhythmia.

Air Cuff Transducer Design for Occlusion-Based Hemodynamic Measurements—An Experimental and Simulation Study

In standard clinical practice, cuff devices are widely used for non-invasive blood pressure measurements (NIBP). However, cuff-based NIBP is prone to large errors especially in cases of hypo- and hypertension. In addition to this, the cuff measurement principle allows for estimation of a number of other hemodynamic parameters (e. g. cardiac output, arterial stiffness, augmentation index) by means of analysis of the pulse waveform and/or pulse amplitude recorded in the cuff pressure. However, in standard practice, the cuff is still only used for the measurement of BP.A key reason for the observed measurement errors and the limited set of extracted parameters lies in our poor understanding of the cuff device as a transducer; the cuff pressure response to arm volume pulsations (the cuff transfer function <i>TF</i>_cuff) depends on a large number of factors. It is not yet clear to what extent the cuff contributes to the NIBP error, or if the cuff in its current format is reliable for measurement of arterial pulse waveform/amplitude. In this study, we investigate the isolated cuff in order to gain a better understanding of the main sources of measurement errors. By using an experimental setup which measures the cuff response to mechanically simulated arm pulsations, we find that the cuff can explain part of the NIBP errors in cases of hypotension. Also, we find that pulse waveforms can be estimated using a standard cuff; however, measurement of the pulse volume amplitude is unfeasible. We demonstrate that the observed inaccuracies can be eliminated by usage of a calibrator device which obtains real-time information on <i>TF</i>_cuff. These findings will enable further investigation of the effects related to the pulse travel along the compressed limb and the interaction between cuff, arm tissue, distal arm hemodynamics and arterial walls for the development of improved occlusion-based measurement strategies.

Low-frequency response test device of electret condenser microphone

Arterial pulse measurement using electret condenser microphone requires the standard to validate the value of the measurement. This standard requires the test device to reproducing the mechanical vibration to emulate the arterial pulse vibration. The main objective of this paper is to discuss the test device of electret condenser microphone using class A amplifiers and low-frequency loudspeaker. To validate this pulse measurement, this class a amplifier is examined under an experimental setup. The experiments showed that the device can be used as an alternative solution to generate the mechanical signal source to simulate the human arterial pulse.

Flexible and Stretchable Electronic Skin with High Durability and Shock Resistance via Embedded 3D Printing Technology for Human Activity Monitoring and Personal Healthcare

AbstractElectronic skin (e‐skin) integrating pressure sensors and strain sensors has shown great potential applications in smart robotics and healthcare monitoring for their flexibility and wearability. However, making the sensor low cost and highly durable for industrialization and commercialization is still a problem to be addressed. An embedded 3D printing technology is developed based on novel thermosetting printing ink which is prepared using the Ecoflex and carbon nanoparticles. The properties of the printing ink including printability and electrical conductivity are first studied and then optimized. By using this technology, a glove‐shaped e‐skin integrating both strain sensors and pressure sensors is fabricated, and the properties of the sensors are studied. Both types of sensors have excellent stability and reliability which are verified by multiple long‐term measurements (10 000 testing cycles). Specifically, the sensors possess a great shock resistance and high durability which are significant for application in real life. Furthermore, some applications for human activity monitoring and personal healthcare are demonstrated, including complex gesture recognition using 15 strain sensors, hardness sensing using pressure sensors coupled with strain sensors, and arterial pulse measurement using pressure sensors, which are promising for smart robotic sensing and wearable biomedical devices.

Effect of work posture on operator complaints: Choice between sitting and standing work

Workers perform manual handling activities with sitting and standing work postures. In sitting work posture, this activity is performed using a 15-cm-long spade, so the workers must bend both their bodies and feet, meanwhile in standing work posture, workers use stainless steel squeegee. Workers on both postures complain of pain but on different parts of the body. Limited work facilities cause this handling activity uses body muscle repetitively. The aim of this study is to obtain an ergonomic work facility so that workers can use standing work posture with minimal pain complaints. The methods used are arterial pulse measurement, pain complaints measurement, anthropometry measurement, and designing handling device using QFD method. The subjects in this study are 6 male workers in a steel company producing threaded steel. The handling device stands 77.9 cm tall with a 15° slope so that silicomanganese can move down by taking advantage of the vibration. Workers only direct silicomanganese into the sack in standing work posture, so that performance can increase.

A Fiber Bragg Grating Sensor for Radial Artery Pulse Waveform Measurement.

In this paper, we report the design and experimental validation of a novel optical sensor for radial artery pulse measurement based on fiber Bragg grating (FBG) and lever amplification mechanism. Pulse waveform analysis is a diagnostic tool for clinical examination and disease diagnosis. High fidelity radial artery pulse waveform has been investigated in clinical studies for estimating central aortic pressure, which is proved to be predictors of cardiovascular diseases. As a three-dimensional cylinder, the radial artery needs to be examined from different locations to achieve optimal pulse waveform for estimation and diagnosis. The proposed optical sensing system is featured as high sensitivity and immunity to electromagnetic interference for multilocation radial artery pulse waveform measurement. The FBG sensor can achieve the sensitivity of 8.236nm/N, which is comparable to a commonly used electrical sensor. This FBG-based system can provide high accurate measurement, and the key characteristic parameters can be then extracted from the raw signals for clinical applications. The detecting performance is validated through experiments guided by physicians. In the experimental validation, we applied this sensor to measure the pulse waveforms at various positions and depths of the radial artery in the wrist according to the diagnostic requirements. The results demonstrate the high feasibility of using optical systems for physiological measurement and using this FBG sensor for radial artery pulse waveform in clinical applications.

A novel method for pulsometry based on traditional iranian medicine

Arterial pulse measurement is one of the most important methods for evaluation of healthy conditions. In traditional Iranian medicine (TIM), physician may detect radial pulse by holding four fingers on the patient's wrist. By using this method, under standard condition, the detected pulses are subjective and erroneous, in case of weak and/or abnormal pulses, the ambiguity of diagnosis may rise. In this paper, we present an equipment which is designed and implemented for automation of traditional pulse detection method. By this novel system, the developed noninvasive diagnostic method and database based on the TIM are way forward to apply traditional medicine and diagnose patients with present technology. The accuracy for period measuring is 76% and systolic peak is 72%.

Simulations of piezoelectric pressure sensor for radial artery pulse measurement

Abstract A radial artery pulse is used to diagnose human body constitution (Prakruti) in Ayurveda. A system consisting of piezoelectric sensor (22 mm × 12 mm), data acquisition card and LabView software was used to record the pulse data. The pulse obtained from the sensor was noisy, even though signal processing was done. Moreover due to large sized senor accurate measurements were not possible. Hence, a need was felt to develop a sensor of the size of the order of finger tip with a resonant frequency of the order of 1 Hz. A micromachined pressure sensor based on piezoelectric sensing mechanism was designed and simulated using CoventorWare. Simulations were carried out by varying dimensions of the sensor to optimize the resonant frequency, stresses and voltage generated as a function of applied pressure. All simulations were done with pressure ranging of 1–30 kPa, which is the range used by Ayurvedic practitioners for diagnosis. Preliminary work on fabrication of such a sensor was carried out successfully.

Modeled Decomposition of Aortic Pressure Waveforms Does Not Provide Estimates for Pulse Wave Velocity

To the Editor: With great interest we have read the article by Qasem and Avolio,1 in which they propose a new method to determine aortic pulse wave velocity (PWV) from waveform decomposition of the central aortic pressure pulse as derived from a single radial artery pulse measurement. The pulse transit time in the aorta is estimated by determining the time difference between the derived forward and backward waves. The validity of the pulse transit time assessment was tested in 2 groups of subjects. In the first group, the relation between measured carotid-femoral artery transit time and pulse transit time was determined using a regression model, and in the second group, the outcome of this relation was tested with presumed independent methods. Measurement of aortic PWV, an important predictor of cardiovascular risk in humans, …

Ultrasound measurement of mandibular arterial blood supply: Techniques for defining ischemia in the pathogenesis of alveolar ridge atrophy and tooth loss in the elderly?

To adapt ultrasound methods used to measure blood flow in the extremities to quantify mandible blood flow in order to determine the role of ischemia in the pathogenesis of mandible atrophy and tooth loss in the elderly. Doppler and duplex ultrasound techniques as used in measurement of arterial pulse in the extremities were adapted for recording the intraoral pulse profile at 7 sites in 57 patients of varying ages. After omitting the large number (26 patients) with signals of indeterminate strength, the mental artery pulse was strong in 11 of 12 (92%) in those younger than 65 versus 9 of 19 (47% in those older than 65 years; P = .02). The equivalent figures for the sublingual artery were 15 of 15 strong for those younger than 65 and 11 of 17 (65%) for those older than 65 years ( P = .02). The varying depth of soft tissue overlying the inferior alveolar artery made its signal difficult to evaluate, but there was no statistically significant age-related difference in the inferior alveolar artery signals. In 4 elderly patients (2 with established carotid artery disease), Doppler and duplex scanning showed reversal of mental artery flow, indicating collateral flow to the mandible. Ultrasound Doppler techniques used for measuring peripheral arterial flow can be adapted to quantify mandible alveolar ridge perfusion. This provides means to evaluate the role of arterial obstruction in mandible alveolar ridge atrophy and tooth loss in the elderly. The mental artery is the best site for this purpose. Preliminary data suggest an age-related reduction in mental artery flow.

Underestimation of Vasodilator Effects of Nitroglycerin by Upper Limb Blood Pressure

To determine why upper limb blood pressure measurement underestimates the vasodilator effects of nitroglycerin on lowering ascending aortic systolic pressure, we studied 24 patients (58 +/- 11 years, mean +/- SD). Ascending aortic pressure and radial artery pulse calibrated by cuff blood pressure measurement at the brachial artery were recorded simultaneously before and 5 minutes after sublingual administration of 0.3 mg nitroglycerin. Waves were analyzed by a signal processor, and the fourth derivative wave was used to find the early (S1) and late (S2) systolic shoulders (S1 corresponds to the second zero crossing and S2 to the third zero crossing). Before nitroglycerin administration, maximal systolic pressure in the ascending aorta (141 +/- 21 mm Hg) coincided with the late systolic peak in all patients, and in most patients (21 of 24) maximal systolic pressure in the radial artery (140 +/- 19 mm Hg) coincided with the early systolic peak. Maximal systolic pressure decreased more in the ascending aorta than in the radial artery (22 +/- 13 and 11 +/- 11 mm Hg, respectively; P < .001). However, the reduction in the shoulder of late systolic pressure in the radial artery (24 +/- 13 mm Hg) clearly indicated the reduction in maximal systolic pressure (late systolic peak) in the ascending aorta. The augmentation index of the ratio of the height of late systolic pressure to early systolic pressure fell proportionally (r = .74, P < .001) in the radial artery (from 0.88 +/- 0.13 to 0.60 +/- 0.11) and in the ascending aorta (from 1.57 +/- 0.25 to 1.26 +/- 0.24), which indicated the reduction in late systolic pressures.(ABSTRACT TRUNCATED AT 250 WORDS)