75 results about "Pulse wave propagation" patented technology

A blood pressure monitoring apparatus which continuously estimates and monitors the blood pressure by using the pulse wave propagation time can accurately estimate the blood pressure. While an estimated blood pressure is continuously calculated by using the pulse wave propagation time, the correlation between the pulse wave propagation time and the interval between feature points contained in two consecutive heart beat waveforms of an electrocardiogram is monitored. If the correlation is reversed, the blood pressure is actually measured, and the estimated blood pressure is corrected on the basis of the difference between the estimated blood pressure and actually measured blood pressure.

A blood pressure monitoring system includes a blood pressure measurement device for measuring blood pressure using a cuff, a memory for storing an externally inputted pulse wave propagation time fluctuation threshold, a time interval detection reference point detection section for detecting a time interval detection reference point in a pulse wave on the side of aortae of a living organism, a pulse wave detection section for detecting a pulse wave on the side of peripheral blood vessels appearing with a time lag with respect to the pulse wave on the side of aortae, a pulse wave propagation time measurement section for measuring a pulse wave propagation time based on respective detected outputs from the time interval detection reference point detection section and the pulse wave detection section, an operation device for calculating a pulse wave propagation fluctuation from two measured pulse wave propagation times, a judgment device for judging whether or not the calculated pulse wave propagation time fluctuation exceeds the pulse wave propagation time fluctuation threshold read from the memory, and a control device for controlling the blood pressure measurement device based on an output of the judgment device so that the blood pressure of a subject is measured using the cuff.

In blood pressure monitoring apparatus which continuously estimates and monitors blood pressure by using the pulse wave propagation time, blood pressure fluctuation can be accurately estimated. If both blood pressure estimated from the pulse wave propagation time and a waveform parameter obtained from the accelerated pulse wave have abnormal values, it is determined that the blood pressure is truly fluctuating, and blood pressure measurement by another method, e.g., blood pressure measurement using a cuff is performed.

Provided is an arterial stiffness evaluation apparatus using a new arterial stiffness index which serves as an index to evaluate a degree of arterial stiffness, and a program therefor. The arterial stiffness apparatus includes pulse wave detecting means, pulse wave propagation velocity deciding means, blood pressure detecting means, and arterial stiffness index calculating means, in which the arterial stiffness index calculating means executes: a first step of calculating a pulse wave propagation velocity PWVori after pressure calibration and CAVI=ln(Ps/Pd)×PWV², and deriving a regression equation where PWVori is represented by a quadratic equation of CAVI; a second step of setting the regression equation as an equation representing a arterial stiffness index PWVpcm1; a third step of deriving a regression equation where the PWVori is represented by a linear equation of the PWVpcm1; a fourth step of setting the regression equation as an equation representing an arterial stiffness index PWVpcm2; and a fifth step of obtaining a PWVpcm2 value by substituting a measured value, and the degree of arterial stiffness is evaluated based on the PWVpcm2.

The invention relates to the field of biomedical monitoring, in particular to a non-contact blood pressure measuring method which does not restrain a human subject. According to the non-contact bloodpressure measuring method, a single biomedical radar is adopted to be aligned with the abdomen and the back of the human subject, then the human subject is required to hold breath, an aorta pulse wavewaveform signal collected during breath holding is recorded, feature extraction is conducted through an EMD algorithm, all feature points of the aorta pulse wave waveform signal are obtained, and themapping relation of each feature point and the time period of a pulse wave is determined; according to the mapping relation, the pulse wave propagation time which corresponds to the aorta pulse wavewaveform signal and is obtained by the biomedical radar is obtained; and a corresponding blood pressure value can be obtained through the pulse wave propagation time. Compared with a traditional bloodpressure value measuring method, only a single radio frequency senor is needed in the measuring method, precision is higher, and the obvious advantages that instrument contact is not needed and the human subject is not retrained are achieved. The non-contact blood pressure measuring method is effective and feasible, the property is reliable, and the blood pressure value can be obtained accurately.

The invention relates to a method for measuring a local pulse wave propagation speed of a carotid blood vessel, which comprises the following steps: a step 1 of designing an ultrafast comb-tooth-shaped focus beam transmitting and receiving sequence and simultaneously acquiring a plurality of points of radio frequency echo signals in the long axis direction of the carotid blood vessel; a step 2 of identifying and tracking an echo signal of front and rear walls of the vessel in each scanning line after carrying out filtering preprocessing on a plurality of focus beam echo signals, which are simultaneously received, in the long axis direction of the carotid blood vessel; a step 3 of respectively carrying out one-dimensional self-correlation phase shifting estimation on adjacent frames of echo signals of the front and rear walls of the vessel in each scanning line to obtain a corresponding phase shifting speed waveform and then obtaining a corresponding phase shifting waveform of the vessel wall along with variation of a cardiac cycle in each scanning line; a step 4 of calculating relative time delay between the phase shifting waveforms of the vessel wall in the adjacent scanning lines and carrying out linear fitting on the time delay so as to obtain a reciprocal of a slope, i.e. the estimated local pulse wave propagation speed. The method provides new basis for early detection of the atherosclerosis.

Provided is a pulse wave propagation detection system including electrocardiographic signal detection means, and eyeground image detection means for detecting an eyeground image in synchronization with an electrocardiographic signal detected through the detection means, which system further includes means for correlating a change in the diameter of an eyeground vein—which diameter is measured, at the optic papilla, by use of an eyeground image synchronized with an arbitrary electrocardiographic signal—with the state of pulse wave propagation through an intracerebral blood vessel or with the state of sclerosis of a capillary artery. Provision of the pulse wave propagation detection system; i.e., means for conveniently and accurately identifying the state of blood flow in the brain or the state of sclerosis of a capillary artery, enables prevention of adverse effects of, for example, excessive drop in blood pressure.

In the measurement device, the blood pressure of the upper arm and the blood pressure of the lower limb are measured using cuffs attached to the upper arm and the lower limb (ankle), respectively. The pulse wave of the upper arm and the pulse wave of the lower limb are measured in synchronization using such cuffs. The upper arm-lower limb pulse wave propagation velocity (baPWV) is calculated based on the appearance time difference of the two pulse waves. The upper arm pulse wave propagation velocity (upper arm PWV) is calculated based on the appearance time difference of the ejection wave and the reflection wave in the upper arm pulse wave. If the values of such propagation velocities are different, a warning is issued.

The invention discloses a measuring method and a measuring device for pulse wave propagation time. The method comprises: synchronously collecting a pulse wave signal and an electrocardiogram signal ofa measured person, extracting characteristic points of the pulse wave signal and the electrocardiogram signal, and calculates a pulse conduction time PAT. The pre-ejection PEP was calculated according to the electrocardiogram signal. The pulse wave propagation time (PTT) is obtained by subtracting the pre-ejection PEP from the calculated pulse propagation time (PAT). The invention eliminates theinfluence of the pre-ejection period and improves the measurement accuracy of the pulse wave propagation time PTT.

A biological-information detecting apparatus includes a first blood-flow measuring device provided at a seat surface of a seat, the first blood-flow measuring device measuring a condition of a blood flow of a popliteal artery of a measurement subject seated in the seat, a second blood-flow measuring device provided at a back of the seat, the second blood-flow measuring device measuring a condition of a blood flow of a thoracic aorta of the measurement subject, and a blood-pressure calculation device determining a pulse-wave propagation velocity and a degree of arteriosclerosis from blood flow data acquired by the first blood-flow measuring device and blood flow data acquired by the second blood-flow measuring device and calculating blood pressures of the popliteal artery and the thoracic aorta of the measurement subject based on the pulse-wave propagation velocity and the degree of arteriosclerosis.