Pulsecor Ltd

Auckland, New Zealand

Pulsecor Ltd

Auckland, New Zealand
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Lan H.,Auckland University of Technology | Al-Jumaily A.M.,Auckland University of Technology | Lowe A.,Pulsecor Ltd | Hing W.,Auckland University of Technology
Medical Engineering and Physics | Year: 2011

This paper presents a 3D finite element upper arm model, validated by experiments as well as clinical data, used to study the error introduced in blood pressure measurements due to variability of arm tissue mechanical properties. The model consists of three separate cylindrical parts: soft tissue, bone and brachial artery. The artery volume changes under the cuff are used to represent the cuff pressure oscillations for analyzing blood pressure measurements. These oscillation trends are identical to observed clinical data. Also an upper arm simulator is designed and built for model validation. The model shows that the variation of soft tissue compressibility introduces an error up to 5% in blood pressure measurements. It is also revealed that the variation of the brachial artery and arm tissue stiffness has an insignificant effect on oscillometric blood pressure measurement method. © 2011 IPEM.


Lin A.C.W.,Green City | Lowe A.,Auckland University of Technology | Lowe A.,Pulsecor Ltd. | Sidhu K.,Green City | And 3 more authors.
Journal of Hypertension | Year: 2012

Background: Central arterial pressure is a better predictor of adverse cardiovascular outcomes than brachial blood pressure, but noninvasive measurement by applanation tonometry is technically demanding. Method: Pulsecor R6.5 is a novel device adapted from a standard sphygmomanometer which estimates the central aortic pressure from analysis of low-frequency suprasystolic waveforms at the occluded brachial artery. A physics-based model, which simulates the arterial system using elastic, thin-walled tube elements and Navier-Stokes equations, is used to calculate arterial pressure and flow propagation. To determine the reliability of the device, we compared 94 central systolic pressures estimated by Pulsecor to the simultaneous directly measured central aortic pressures at the time of coronary angiography in 37 individuals. Results: There was good correlation in central SBP between catheter measurements and Pulsecor estimates by either invasive or noninvasive calibration methods (r=0.99, P<0.0001 and r=0.95, P<0.0001, respectively). The mean difference in central systolic pressure was 2.78 (SD 3.90)mmHg and coefficient of variation was 0.03 when the invasive calibration method was used.When the noninvasive calibration method was used, the mean difference in central systolic pressure was 0.25 (SD 6.31)mmHg and coefficient of variation was 0.05. Conclusion: We concluded that Pulsecor R6.5 provides a simple and easy method to noninvasively estimate central SBP, which has highly acceptable accuracy. © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins.


Al-Jumaily A.,Auckland University of Technology | Lowe A.,Pulsecor Ltd
Mathematical and Computer Modelling | Year: 2013

This paper investigates the effect of the various terms in the one-dimensional acoustic wave equation on the pulse characteristics within the aorta. To mimic the physiological nature of the systemic arteries, the aorta is modelled as an elastic conical tube. The frequency spectrum is used to study the effect of different terms in this equation on the pressure ratio between the aortic root at the heart exit and the iliac bifurcation. For validation, the effective reflection distance calculated using this model is within 7% error of clinical observations, suggesting that the model is able to mimic physiological pressure propagation with a high degree of accuracy and can therefore be used to generate and test hypotheses. This work demonstrates that: (i) tapering in the aorta lumen radius causes supplementary amplification of the pressure pulses in the system and increases the propagation velocity; however, tapering in the aorta wall thickness generates opposite effects, (ii) increasing the wall stiffness causes a change in the natural frequency of the system and increases the propagation velocity, and (iii) inclusion of either the advective momentum correction term or the viscosity term insignificantly affects the pressure ratio. The last observation suggests that the flow pattern does not influence the pressure propagation characteristics. © 2012 Elsevier Ltd.


Trademark
Uscom Ltd. and Pulsecor Ltd. | Date: 2013-04-09

MEDICAL APPARATUS FOR NON-INVASIVE OSCILLOMETRIC MEASUREMENT OF BLOOD PRESSURE SIGNALS AND FOR PROVIDING PHYSIOLOGICAL INFORMATION IN ADDITION TO BLOOD PRESSURE.


Trademark
Uscom Ltd. and Pulsecor Ltd. | Date: 2013-03-26

MEDICAL APPARATUS FOR NON-INVASIVE OSCILLOMETRIC MEASUREMENT OF BLOOD PRESSURE SIGNALS AND FOR PROVIDING PHYSIOLOGICAL INFORMATION IN ADDITION TO BLOOD PRESSURE.


Trademark
Uscom Ltd. and Pulsecor Ltd. | Date: 2013-03-26

MEDICAL COMPUTER SOFTWARE FOR PROCESSING NON-INVASIVELY OBTAINED OSCILLOMETRIC BLOOD PRESSURE SIGNALS AND PROVIDING PATIENT PHYSIOLOGICAL INFORMATION IN ADDITION TO BLOOD PRESSURE.


Bp+

Trademark
Uscom Ltd. and Pulsecor Ltd. | Date: 2013-01-01

MEDICAL APPARATUS FOR NON-INVASIVE OSCILLOMETRIC MEASUREMENT OF BLOOD PRESSURE SIGNALS AND FOR PROVIDING PHYSIOLOGICAL INFORMATION IN ADDITION TO BLOOD PRESSURE.


Mookerjee A.,University of Auckland | Al-Jumaily A.M.,University of Auckland | Lowe A.,Pulsecor Ltd
Biomechanics and Modeling in Mechanobiology | Year: 2010

Different characteristic points used for the evaluation of pulse wave velocity (PWV) give significantly different results. Hence, the accuracy of using these points is questionable. There is need for quantitative comparison of different techniques to determine PWV. Previous studies aimed at comparing different PWV measurement techniques have been noted, however, on a limited number of smaller animals (mice, dogs, etc.). This simulation-based study aims to compare different techniques for PWV measurement in a large representative human population. A computer model is developed for simulating the pressure wave propagation between the carotid and femoral arteries. Using relationships observed in clinical trials, the model input parameters for a statistically representative population are expressed in terms of a person's age, gender and height. The model is used to calculate the carotid-femoral pressure ratio for different individuals, which is then parameterised into a number of features, and the equivalent propagation time is calculated using the phase-slope method. Using this time, the apparent phase velocity is determined and compared with PWV determined by the foot-to-foot technique. The two velocities compare well with a difference of 0.0059±0.0904 m/s. An averaging criterion for the calculation of apparent phase velocity has been tested and shown to give good estimates compared to the foot-to-foot technique. As it does not involve the identification of characteristic points on the measured pressure waves, the phase-slope method is more suitable for implementation in PWV monitors. © 2010 Springer-Verlag.


A method and apparatus determine certain cardiac medical parameters that are useful is diagnosing cardiovascular disease. The apparatus is designed to carry out the method, which includes the steps of:


Trademark
Pulsecor Ltd. | Date: 2011-08-18

MEDICAL APPARATUS FOR NON-INVASIVE OSCILLOMETRIC MEASUREMENT OF BLOOD PRESSURE SIGNALS AND FOR PROVIDING PHYSIOLOGICAL INFORMATION IN ADDITION TO BLOOD PRESSURE.

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