103 results about "Arterial blood flow" patented technology

A method and apparatus for non-invasively evaluating endothelial activity in a patient, particularly for indicating the presence of an endothelial dysfunction condition, by applying an occluding pressure to a predetermined part of an arm or leg of the patient to occlude arterial blood flow therein; maintaining the occluding pressure for a predetermined time period; removing the occluding pressure after the elapse of the predetermined time period to restore arterial blood flow; monitoring a digit of the arm or leg by a digit-probe for changes in the peripheral arterial tone therein before and after the application of the occluding pressure to the arm or leg of the patient; and utilizing any detected changes in the peripheral arterial tone for evaluating endothelial activity in the patient. Particularly important advantages are provided when the occluding cuff is applied to the digit of the patient receiving the monitoring digit-probe, on the proximal side thereof with respect to the patient's heart, and also when a reference digit-probe is applied to another digit, not influenced by the occluding pressure, to compensate for shifts inherent to vascular beds.

A technique is disclosed for determining blood flow in a living body by changing the thermal energy level in the venous blood flow path and determining temperatures in both the venous and arterial blood flow paths. Blood flow is calculated as a function of the change in energy level and the temperature differences in the venous and arterial blood flow paths.

Devices, systems, and methods for organ retroperfusion. In at least one embodiment of a method of organ perfusion of the present disclosure, the method comprises the steps of positioning at least part of a first catheter having a cannula within an artery of a patient, the first catheter configured to permit arterial blood to flow therethrough and further configured to permit a portion of the arterial blood to flow through the cannula, positioning at least part of a second catheter within a vein of the patient at or near a target organ, the second catheter configured to receive some or all of the portion of the arterial blood, and connecting the cannula of the first catheter to a portion of the second catheter so that some or all of the portion of the arterial blood flowing through the cannula is provided into the vein to treat a condition or disease of the target organ.

Disclosed herein are exemplary embodiments of an impulse therapy garment for use in pump therapy for enhancing venous and arterial blood flow. The garment may be advantageously fitted to a human foot, and may include a rotationally positionable heel-strap, an air inlet connector, separate dorsum straps, or other features. For example, other garments may include a washer having a center hole locatable around the stem and configured to be forcibly retained against the outer surface of the fabric by snap-fit using annular stem protrusions extending from an external surface of the stem. In further embodiments, a garment may include a bladder retention fastener configured to retain an end of the bladder to the fabric to allow substantially differential movement between the fabric and non-retained portions of the bladder during inflation and deflation of the bladder.

Interventional procedures on the carotid arteries are performed through a transcervical access while retrograde blood flow is established from the internal carotid artery to a venous or external location. A system for use in accessing and treating a carotid artery includes an arterial access device, a shunt fluidly connected to the arterial access device, and a flow control assembly coupled to the shunt and adapted to regulate blood flow through the shunt between at least a first blood flow state and at least a second blood flow state. The flow control assembly includes one or more components that interact with the blood flow through the shunt.

Methods and devices provide for temporary partial aortic occlusion to achieve diversion of blood flow to the brain in patients suffering from cerebral ischemia. The device can include an expandable frame with a membrane mounted on a first portion of the frame. The membrane can have at least one opening. In some embodiments, the membrane has an outer region and an inner region, and an opening in the inner region. In use, the frame can expand to conform to the inner walls of the aorta and the membrane can at least partially occlude the aorta thereby increasing cerebral perfusion. The frame can include one or more anchors to aid in maintaining the device in position against the arterial blood flow pressure.

Method and apparatus to non-invasively measure fetal blood oxygen saturation levels. Optical sensors capable of producing and detecting multiple wavelengths of tissue penetrating light are placed on the surface of the maternal abdomen, and the light beams directed to pass through at least a portion of the uterus containing the fetus. The fetal heart rate is monitored by Doppler ultrasound, and pure maternal optical signal related to maternal arterial blood flow are also measured. The optical sensors collect composite signals containing both maternal and fetal hemoglobin absorption spectral data and modulated by their respective pulsatile blood flows. The composite signals processed in the time domain and frequency domain, the pure maternal pulsatile optical signal used to extract the maternal contribution to the composite signal, and the fetal pulsatile signal is used to lock onto and extract the fetal contribution to the composite signal, and a fetal blood oxygen level deduced.

A heart-rate sensor for detecting artery blood-flow volume per unit length change in a human or animal subject, which comprises an antenna for sensing the instantaneous volume of blood in the artery of the subject, to be measured; a RADAR unit for transmitting microwave signals into a subject's body part or limb representing tissue targets. The output of the RADAR unit includes a superposition of signals each of which corresponding to a different tissue target with amplitudes that relate to the target's reflection strength; a sampling circuitry for converting reflected signals to digital; a window function circuitry for suppressing unwanted spectral sidebands originating from the subsequent processor operating on time truncated data; an FFT processor following the window function circuitry, for splitting the superposition according to its relative frequency into a multiplicity of bins, each of which with an amplitude that represents the reflection magnitude of a target at a specific distance from the antenna; a signal processor for filtering out the effect of the sensor movement with respect to the subject body part, or the movement of the body part, and for generating a signal, the amplitude of which is proportional to the artery varying dilatation representing the heart-rate; a heart-rate estimator for measuring the frequency of the artery dilatation variations and for canceling the interference of the amplitude of any signal that does not originate from the artery; a battery for powering the sensor.

A system and method for taking non-invasive blood pressure and other vascular parameter measurements includes placing a vascular compression device about an appendage of a subject. An arterial / venous occlusion cuff is placed about a base of the appendage. The vascular compression device is activated to generate compression ischemia in the appendage. The arterial / venous occlusion cuff is pressurized to generate arterial / venous occlusion in the appendage. The vascular compression device is deactivated. The arterial / venous occlusion cuff is gradually depressurized to allow blood and other body fluids to flow into the appendage and thereupon determine vascular parameters such as, for example, systolic arterial blood pressure, diastolic arterial blood pressure, venous blood pressure, arterial blood flow, blood vessel compliance, and appendage blood volume.