background and objective: the circle of willis (cow) supports adequate blood supply to the brain. the cardiovascular system, in the current study, is modeled using an equivalent electronic system focusing on the cow. method: in our previous study we used 42 compartments to model whole car- diovascular system. in the current study, nevertheless, we extended our model by using 63 compartments to ...

The objective of this paper is to describe current uses of oscillometric pressure pulse waveforms and to introduce several prospective applications of the waveforms. A specialized system (Carditor) for acquisition, processing and display of waveforms is described. Carditor was used to acquire a database of oscillometric blood pressure waveforms from a wrist cuff. The following prospective metho...

The "median" method for the reduction of the effect of noise and trigger jitter on waveform data is described. The effectiveness of this method was examined using simulations and experiments and, for typical jitter and noise observed in electrical pulse metrology, is shown to provide reconstructed waveforms with transition durations that accurately match those of the input signal. Also, for abe...

-Waveforms of blood pressure contain very important signals of life. Although blood pressure can be continuously measured by an intra arterial catheter, this invasive method introduces risks to patients. Knowing that blood pressure can change in just a few seconds or minutes without a sensible feeling, the waveforms of blood pressure are capable of conveying substantial cardiovascular informati...

The N-point moving average (NPMA) is a mathematical low-pass filter that can smooth peaked noninvasively acquired radial pressure waveforms to estimate central aortic systolic pressure using a common denominator of N/4 (where N=the acquisition sampling frequency). The present study investigated whether the NPMA method can be applied to brachial pressure waveforms. In the derivation group, simul...

Transfer function techniques are increasingly used for non-invasive estimation of central aortic waveform characteristics. Non-invasive radial waveforms must be calibrated for this purpose. Most validation studies have used invasive pressures for calibration, with little data on the impact of non-invasive calibration on transfer-function-derived aortic waveform characteristics. In the present s...

OBJECTIVE To discover design principles underlying the optimal waveforms for external chest and abdominal compression and decompression during cardiac arrest and cardiopulmonary resuscitation (CPR). METHOD A 14-compartment mathematical model of the human cardiopulmonary system is used to test successive generations of randomly mutated external compression waveforms during cardiac arrest and r...

This paper describes a method that uses two cuffs to improve accuracy of blood pressure and hemodynamics estimation. A specially designed dual-cuff experimental system was used to acquire and process data from the two cuffs. The arm cuff provided cuff pressures and cuff arterial pulse waveforms. The arm cuff pulse pressure waveforms were used to compute mean arterial pressure (MAP), systolic pr...