129 results about "Vascular resistance" patented technology

A method and apparatus of automatically locating in an image of a blood vessel the lumen boundary at a position in the vessel and from that measuring the diameter of the vessel. From the diameter of the vessel and estimated blood flow rate, a number of clinically significant physiological parameters are then determined and various user displays of interest generated. One use of these images and parameters is to aid the clinician in the placement of a stent. The system, in one embodiment, uses these measurements to allow the clinician to simulate the placement of a stent and to determine the effect of the placement. In addition, from these patient parameters various patient treatments are then performed.

A long-term implantable arterio-venous shunt device or creation of a fistula is provided that can be used as a therapeutic method for treating chronic obstructive pulmonary disease (COPD). The shunt device is implanted between an artery and a vein, preferably between a peripheral artery and the inferior vena cava. The shunt device and method of creating a fistula increases cardiac output and decreases the systemic vascular resistance and allows a blood flow rate through the shunt device of at least 5 ml/min after the implantation. Based on the effects of the method and device to the respiratory, cardiac and circulatory system, the method and device are beneficial as a therapy to patients with problems or conditions related to these systems.

A method and apparatus of automatically locating in an image of a blood vessel the lumen boundary at a position in the vessel and from that measuring the diameter of the vessel. From the diameter of the vessel and estimate blood flow rate, a number of clinically significant physiological parameters are then determine and various user displays of interest generated. One use of these images and parameters is to aid the clinician in the placement of a stent. The system, in one embodiment, uses these measurements to allow the clinician to simulate the placement of a stent and to determine the effect of the placement. In addition, from these patient parameters various patient treatments are then performed.

A long-term implantable arterio-venous shunt device is provided that can be used as a therapeutic method. The shunt device is implanted between an artery and a vein, preferably between the aorta and the inferior vena cava. The shunt device decreases the systemic vascular resistance and allows a blood flow rate through the shunt device of at least 5 ml/min after the implantation. The blood flow rate could be controlled either via an open loop or a closed loop control means. The shunt device could also be a self-adjustable shunt device to self-adjust its structure to control the blood flow rate through its lumen. Based on the effects of the shunt device to the respiratory, cardiac and circulatory system, the implantable shunt device could be beneficial as a therapy to patients with problems or conditions related to these systems.

An arterially measured pressure signal is continuously read in and temporarily stored in the working memory (RAM). The function p(t) is processed by the central processing unit (CPU), to calculate the heart/time volume PCCO and other hemodynamic parameters. The calculation comprises the following steps: The systemic vascular resistance SVR_k is calculated for the current pulse period. The stroke volume SV_k is numerically determined from the pressure values of a pulse period, according to the following equation: ${\mathrm{SV}}_k\propto \sum \left(\frac{p_i\left(t\right)}{{\mathrm{SVR}}_k}+C_k\left(p_i\right)\frac{d{p}_i}{dt}\right)$

with the compliance C(p)=(MAP−CVP)_k/[SVR·<dp/dt>_k]·f(p). The difference between the mean arterial pressure MAP and the central venous pressure CVP, and the mean incline of the pressure curve in the diastole <dp/dt>, are re-determined for the current pulse period. The heart/time volume calculated in the current pulse period results from PCCO_k=SV_k·HR. Therefore, continuous recalibration of the systemic vascular resistance and of the compliance takes place, from the continuously determined pressure measurement data.

A non-invasive device for evaluating circulatory state parameters, and specifically, a pulsewave analysis device capable of evaluation by separating blood vessel compliance and blood vessel resistance into central and peripheral components of the arterial system is provided. Microcomputer 4 detects the waveform at a test subject's radius artery via pulsewave detector 1, and uptakes the stroke volume in the test subject which is measured by a stroke-volume measurer. Next, based on the measured stroke volume, microcomputer 4 adjusts the values of each element in a lumped five parameter model made up of an electrical circuit which models the arterial system from the center to the periphery of the body, so that the response waveform obtained when an electric signal corresponding to the pressure waveform at the proximal portion of the aorta in a test subject is provided to the electric circuit coincides with the waveform at the radius artery. Microcomputer 4 then outputs the thus-obtained values of each element as circulatory state parameters. In addition, microcomputer 4 calculates the diastolic pressure value, systolic pressure value and pulse waveform at the proximal portion of the aorta from the values of each element, and outputs the calculated result to output device 6.

Methods and apparatuses for a tissue mechanical property monitoring system are disclosed herein. In one embodiment, a tissue mechanical property monitoring system is disclosed. The tissue mechanical property monitoring system may comprise a probe, wherein the probe comprises a light source and a photodetector; and a main unit, wherein the main unit comprises a microcontroller and wireless transmitter. The probe may be hermetically sealed and may be capable of being implanted onto tissue. The photodetector may be capable of collecting reflectance data from the light emitted by the light source. The reflectance data may be capable of being sorted and processed into tissue mechanical property data such as tissue compliance, vascular resistance, and the like for the tissue illuminated with the probe.

A method is disclosed for using fructose-1,6-diphosphate (FDP) to reduce and prevent two very serious problems caused by surgery that requires cardiopulmonary bypass. Before bypass begins, a liquid that contains FDP is intravenously injected into the patient, preferably over a period such as about 10 to 30 minutes, to allow the FDP to permeate in significant quantity into the heart and lungs while the heart is still beating. FDP can be added to the cardioplegia solution that is pumped through the heart to stop the heartbeat, and/or during bypass. This treatment was found to reduce two very important and serious problems that have unavoidably plagued CPB surgery in the past, which are: (1) elevated levels of pulmonary vascular resistance (PVR), which includes pulmonary hypertension; and (2) high occurrence rates for atrial fibrillation. Prior to this discovery, there has never been any satisfactory treatment which could reduce the severity and occurrence rates for these two major problems. FDP also can be co-administered in this manner, along with (1) a buffering or alkalizing agent that counteracts acidosis, such as sodium bicarbonate or THAM, and/or (2) a drug that reduces the formation of lactic acid, such as dichloroacetate.

The invention relates to acquiring information concerning the hemodynamic status of the brain (or any other organ) by measuring and analysing the pulsatile properties of blood flow (velocities) in the organ's feeding vessels in relation to the pulsatile properties of the systemic arterial blood pressure. Provided is a system for the analysis of arterial blood flow velocity measurements, comprising means for receiving input signals delivered by an arterial blood flow velocity (FV) sensor and by an arterial blood pressure (BP) sensor, wherein said FV and BP signals are recorded simulataneously and continuously, further comprising means for processing and outputting signals, wherein said processing comprises calculating the pulsatile apparent resistance (PaR) or the Pulse Flow Velocity Mismatch (PFVM). Plotting PAR or PVFM against mean arterial blood pressure and/or end tidal CO2 levels can serve as an indicator for the effectiveness of imposed therapy.

Fructose-1,6-diphosphate (FDP) is used to treat patients who are undergoing coronary artery bypass grafting (CABG) surgery. Before cardiopulmonary bypass begins, a liquid that contains FDP is intravenously infused in the patient, preferably for about 10 to 30 minutes, to allow the FDP to enter the heart and lung tissue while the heart is still beating. FDP can also be added to cardioplegia solution; in addition, FDP can be injected after bypass is terminated, but if post-bypass injection is used, steps should be taken to avoid excess lactic acid accumulation, which appears to increase the risk of atrial fibrillation. To prevent or control lactic acidosis, a buffering or alkalizing agent, such as sodium bicarbonate, or an agent which reduces lactic acid formation, such as dichloroacetate, can be used. In double-blinded trials, this use of FDP substantially reduced heart damage and improved overall outcomes, as shown by lower levels of creatine kinase in blood, improvements in pumping performance, reduced requirements for vasodilator and inotropic drugs, and shorter stays in intensive care units. Certain dosages also reduced the likelihood of atrial fibrillation; however, FDP at high dosages increased the likelihood of A-fib. FDP also helped reduce pulmonary vascular resistance (PVR); this is an important finding, since pulmonary hypertension following cardiopulmonary bypass is a very difficult and often intractable problem, and is a contributing factor in nearly all deaths following CPB surgery.

The invention relates to a blood pressure measurement device an electronic device and a blood pressure measurement method. The blood pressure measurement device includes: a light emitting unit configured to irradiate a living body with measurement light; a light receiving unit configured to receive reflected or transmitted light of the measurement light; and a computational unit configured to calculate a blood flow and a volume pulse wave based on a light-receiving result from the light receiving unit, and to calculate blood pressure based on the blood flow and blood vessel resistance that is obtained from the volume pulse wave.

The invention discloses an orally taken traditional Chinese medicine for treating migraine, and belongs to the field of traditional Chinese medicines. The traditional Chinese medicine is prepared from the following raw materials: astragalus root, lumbricus, ligusticum wallichii, atractylodes macrocephala, Chinese parsnip root, tuckahoe, red paeony root, semen cassiae, radix paeoniae alba, prepared rehmannia root, large-leaved gentian, selfheal, red flower, schizonepeta, chrysanthemum, peach seeds, asarum, radix bupleuri, codonopsis pilosula, angelica sinensis, gastrodia elata, angelica root and fructus viticis. The traditional Chinese medicine is mainly used for realizing the effects of promoting circulation of qi, relieving depression, activating blood, dredging collaterals, reducing phlegm, removing stagnation, expelling wind and alleviating pain, and also achieving the purposes of improving circulation of blood, reducing drag of blood vessels, and increasing the microcirculation blood flow rate. The traditional Chinese medicine has the advantages that the effect is instant, the treatment course is short, the cost is low, and the like.

A method for determining haemodynamic performance in a human or animal subject comprises receiving at a processor data representing haemodynamic variables measured from the subject over time. The haemodynamic variables comprise at least two of Systemic Perfusion Pressure (SPP), Systemic Vascular Resistance (SVR), Cardiac Output (CO), Heart Rate (HR) and Stroke Volume (SV). The data are processed to produce a display signal for causing a display device to present a visual mapping relating the haemodynamic variables according to the relationship SPP=CO×SVR and the visual mapping is displayed on a display device. The visual mapping may be corrected Heart Rate (HR) or include a second mapping which facilitates an adjustment to take account of HR.

A method for evaluating a cardiac function by using pulse waves includes the following steps: (1) acquiring a finger tip photoelectric capacity pulse wave signal through a photoelectric capacity sensor; (2) amplifying and filtering the finger tip photoelectric capacity pulse wave signal; (3) separating alternating quantity; (4) performing analog-to-digital conversion on the alternating quantity, and performing re-sampling on the converted digital signal to acquire a pulse waveform; (5) determining the pulse rate PR by using feature points of the pulse waveform; (6) segmenting the signal by using ascending ramus start point of the pulse waveform, acquiring waveform feature parameters for reflecting the human body cardiovascular resistance and a microvessel microcirculation state, and acquiring parameters including the cardiac output, the cardiac index, the stroke volume, and the stroke index which can reflect the cardiac function. The method can acquire the pulse wave signal of a human body through photoelectric capacity pulse waves, can evaluate the cardiac function through the pulse waves without drawing blood, can avoid injure, is high in adaptability, is simple in detection, is high in efficiency, and can accurately reflect the health condition of the cardiac function.

Systems and methods using a database of physiological information for the design, development, testing and use of therapeutics. In one aspect, the physiological information can include at least one of: hemodynamic monitoring information, pulmonary arterial pressure, cardiac output, heart rate, respiratory rate, peripheral vascular resistance, total peripheral resistance or dicrotic notch information. Optionally, the cardiovascular physiology information can include ambulatory physiological information.