71 results about "Arterial flow" patented technology

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.

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.

The present invention is TAH system for auto-regulating blood flow and maintaining the asymmetric pressure balance in the mammalian cardiovascular system by decreasing the resistance in blood flow and minimizing the pressure gradients to exploit the in-flow pressure sensitivities of continuous flow pumps. The system further includes laminar flow generating manifolds connected to the atrium at one end and attached to pumps linked to the great vessels at the other, such that the in-let flow sensitivities of the pumps are maximized to auto-regulate blood flow, providing adequate pulmonary and systemic arterial flow to support normal metabolism and end-organ function and maintain the appropriate asymmetric physiologic pressure balance between the systemic and pulmonary systems of the mammalian cardiovascular system.

Diagnostic angiograms only provide the projected lumen of a coronary, which is only an indirect measure of blood flow and pressure decline. According to an exemplary embodiment of the present invention, a motion compensated determination of a flow dynamics and a pressure decline for stenosis grading is provided, in which the motion compensation is performed on the basis of a tracking of a first position of a first marker and a second position of a second marker in the projection data set. This may provide for a robust and precise flow dynamics and pressure decline determination.

Devices, systems, and methods for providing retroperfusion to at least one ischemic tissue in a minimally invasive manner are disclosed. At least some of the embodiments disclosed herein enable an anastomosis to be formed between a vein and an artery without the use of sutures and through a non-invasive procedure. In addition, various disclosed embodiments provide a cannula device comprising a Y-configuration for bifurcating arterial flow between an anastomosis and the underlying artery. The devices, systems and methods herein can further provide simultaneous autoretroperfusion therapy to more than one area of an ischemic tissue.

A noninvasive patient-specific method is provided to aid in the analysis, diagnosis, prediction or treatment of hemodynamics of the cardiovascular system of a patient. Coronary blood flow and pressure can be predicted using a 3-D patient image-based model that is implicitly coupled with a model of at least a portion of the remaining cardiovascular system. The 3-D patient image-based model includes at least a portion of the thoracic aorta and epicardial coronaries of the patient. The shape of one or more velocity profiles at the interface of the models is enforced to control complex flow features of recirculating or retrograde flow thereby minimizing model instabilities and resulting in patient-specific predictions of coronary flow rate and pressure. The invention allows for patient-specific predictions of the effect of different or varying physiological states and hemodynamic benefits of coronary medical interventions, percutaneous coronary interventions and surgical therapies.

Optical Coherence Tomography (OCT) is a high-resolution, non-invasive technique to image subsurface tissue and tissue functions. A broadband light source illuminates an object and the reflected photons are processed using an interferometer, demodulated into inphase and quadrature components and then digitized. The captured data contains information about the velocity of the moving scatterers but current Doppler estimation algorithms have a limited velocity detection range. Using a two dimensional velocity estimation, Doppler OCT (DOCT) can be used for the detection of in vivo aortic blood flow rates of over 1 m / s peak velocity through an esophageal DOCT probe. Previous methods have used a transverse Kasai (TK) autocorrelation estimation to estimate the velocity which is good for slow velocities, such as in the microvasculature. By calculating the Kasai autocorrelation with a lag in the depth or axial direction, backscattered frequency information is obtained which yields high velocity rate information. Through subtraction with stationary backscattered information, the Doppler shift is obtained by the axial Kasai (AK) technique. Through utilizing information from two dimensions, velocities can be resolved which spans rates from the microcirculation to cardiac blood flow velocities.

The invention discloses a method for calculating a sampling perfection with application-optimized contrasts by using different flip angle evolutions (SPACE) sequence signal. The method comprises the following steps of: setting blood flow speed as laminar flow distribution; calculating an accumulated phase of an SPACE sequence according to the blood flow speed of the laminar flow distribution; calculating a rotation matrix of the SPACE sequence; calculating a relaxation matrix of the SPACE sequence according to the accumulated phase; calculating the evolution process of a spinning magnetization vector according to the rotation matrix and the relaxation matrix; and according to the evolution process of the spinning magnetization vector, calculating the signal strength of each flow layer, averaging, and thus obtaining the signal strength of blood flow. The blood flow speed is set as the laminar flow distribution, blood flow speed-magnetic resonance imaging (MRI) signal strength distribution which is obtained by calculation according to the Bloch equation can be well matched with experiment data, and a calculation result is accurate. Moreover, the invention also provides a system for calculating the SPACE sequence signal and a method for fitting an aorta blood flow signal according to an SPACE sequence signal accurate calculation method and sampling the aorta blood flow signal. By the invention, optimization of sequence parameters is facilitated.

The present invention is TAH system for auto-regulating blood flow and maintaining the asymmetric pressure balance in the mammalian cardiovascular system by decreasing the resistance in blood flow and minimizing the pressure gradients to exploit the in-flow pressure sensitivities of continuous flow pumps. The system further includes laminar flow generating manifolds connected to the atrium at one end and attached to pumps linked to the great vessels at the other, such that the in-let flow sensitivities of the pumps are maximized to auto-regulate blood flow, providing adequate pulmonary and systemic arterial flow to support normal metabolism and end-organ function and maintain the appropriate asymmetric physiologic pressure balance between the systemic and pulmonary systems of the mammalian cardiovascular system.

In a method and apparatus for examination and evaluation of a blood flow in a pulmonary artery of a patient, measurement data are recorded, from which at least a part of the blood flow in the pulmonary artery is able to be re-constructed at least two-dimensionally in a plane defined by a longitudinal axis of the pulmonary artery and by an anterior-posterior direction, including at least at several diastolic points in time in the course of a heart cycle, after a closure of the pulmonary valve. The number of diastolic points for which an asymmetry in relation to the longitudinal axis of the pulmonary artery in the anterior-posterior direction exists is determined. A measure is then determined that characterizes how long, after the closure of the pulmonary valve, the aforementioned asymmetry exists.

A Doppler sensor for non-invasive continuous Doppler monitoring for arterial blood flow to a distal body part of a patient that employs a Doppler transducer holder for placement at the distal body part of the patient. The holder is adapted to allow the sensor to be inserted and removed, enabling a sterile sensor for each new use. The holder may be disposable after each use, may be provided with a cover for disposal of the cover after each use and re-use of the holder, and the sensor may be provided with a cover for sterile placement against the patient's body.

An ABPI measurement system includes a cuff for each ankle and a cuff for each arm of a patient. Each cuff has first and second chambers. The four cuffs are applied to each limb (or finger or toe), each chamber is inflated simultaneously to a pressure until a Pneumo Arterial Plethysmography (PAPG) signal related to the arterial flow in the limb is detected at the chambers. The second chambers are then simultaneously inflated until the PAPG signals are extinguished in each limb, the inflation of the second chambers continuing for 10 mmHg to 20 mmHg above the extinguishing pressure. The second chambers are then deflated and the pressure in the second chamber at which the PAPG signal returns in the first chamber is recorded for each limb and this value of the pressure is used to calculate the ABPI. The ABPI is displayed or sent to a remote site.