A medical imaging system is described that comprises an heating element configured to apply at least one heating pattern element to a material to locally heat the material; a sensor configured to capture the position of the heated material a predetermined time after the application of the heating pattern element; and circuitry configured to determine the change of the heating pattern applied to the material based upon the captured position of the heated material after the predetermined time.

A medical imaging system is described that comprises an heating element configured to apply at least one heating pattern element to a material to locally heat the material; a sensor configured to capture the position of the heated material a predetermined time after the application of the heating pattern element; and circuitry configured to determine the change of the heating pattern applied to the material based upon the captured position of the heated material after the predetermined time.

Degree of occlusion is monitored for an occlusive device configured to occlude passage of fluid between two compartments in a lumenal space of a body of a patient. In some embodiments, changes in an electrical signal measured from the body of the patient are induced by perturbing the fluid; for example, by “tagging” a portion of fluid with a perturbation of temperature and/or composition. The degree of occlusion is estimated based on the measured changes. The electrical signal changes may be indicative of fluid movements redistributing the perturbed fluid among the two compartments; for example, by diffusion, mixing, and/or jetting of fluid.

An intra-cardiac mapping system is based on locating the ports through which blood flows in or out the heart chambers. For many procedures, such as ablation to cure atrial fibrillation, locating the pulmonary veins and the mitral valve accurately allows to perform a Maze procedure. The location of the ports and valves is based on using the convective cooling effect of the blood flow. The mapping can be performed by a catheter-deployed expandable net or a scanning catheter. The same net or catheter can also perform the ablation procedure.

An intra-cardiac mapping system is based on locating the ports through which blood flows in or out the heart chambers. For many procedures, such as ablation to cure atrial fibrillation, locating the pulmonary veins and the mitral valve accurately allows to perform a Maze procedure. The location of the ports and valves is based on using the convective cooling effect of the blood flow. The mapping can be performed by a catheter-deployed expandable net or a scanning catheter. The same net or catheter can also perform the ablation procedure.

Devices, systems, and methods are disclosed for improved laser speckle imaging of samples, such as vascularized tissue, for the determination of the rate of movement of light scattering particles within the sample. The system includes a structure adjoining a light source and a photo-sensitive detector. The structure can be positioned adjacent the sample (e.g., coupled to the sample) and configured to orient the light source and detector relative the sample such that surface reflections, including specular reflections and diffuse reflections, are discouraged from entering the detection field of the detector. The separation distance along the structure between the light source and the detector may further enable selective depth penetration into the sample and biased sampling of multiply scattered photons. The system includes an operably coupled processor programmed to derive contrast metrics from the detector and to relate the contrast metrics to a rate of movement of the light scattering particles.

Devices, systems, and methods are disclosed for improved laser speckle imaging of samples, such as vascularized tissue, for the determination of the rate of movement of light scattering particles within the sample. The system includes a structure adjoining a light source and a photo-sensitive detector. The structure can be positioned adjacent the sample (e.g., coupled to the sample) and configured to orient the light source and detector relative the sample such that surface reflections, including specular reflections and diffuse reflections, are discouraged from entering the detection field of the detector. The separation distance along the structure between the light source and the detector may further enable selective depth penetration into the sample and biased sampling of multiply scattered photons. The system includes an operably coupled processor programmed to derive contrast metrics from the detector and to relate the contrast metrics to a rate of movement of the light scattering particles.

The invention relates to a system for determining blood flow within a blood vessel (18). A fluid infusion unit (4, 10, 11) continuously infuses a fluid into the blood vessel, and a temperature values determining unit (14, 21) determines simultaneously a first temperature value at a first location and a second temperature value at a second location such that the first temperature value is indicative of the temperature of the fluid and the second temperature value is indicative of the temperature of a mixture of the fluid and the blood. The blood flow is determined based on the measured first and second temperature values and the infusion rate. This kind of determining the blood flow leads to an increased accuracy and is less cumbersome than known techniques requiring a movement of a temperature sensor for measuring temperatures at different locations.

The invention relates to a system for determining blood flow within a blood vessel (18). A fluid infusion unit (4, 10, 11) continuously infuses a fluid into the blood vessel, and a temperature values determining unit (14, 21) determines simultaneously a first temperature value at a first location and a second temperature value at a second location such that the first temperature value is indicative of the temperature of the fluid and the second temperature value is indicative of the temperature of a mixture of the fluid and the blood. The blood flow is determined based on the measured first and second temperature values and the infusion rate. This kind of determining the blood flow leads to an increased accuracy and is less cumbersome than known techniques requiring a movement of a temperature sensor for measuring temperatures at different locations.

A medical system for minimally-invasive measurement of blood flow in an artery (AT). An interventional device (IVD) with an optical fiber (FB) comprising a plurality of temperature-sensitive optical sensor segments, e.g. Fiber Bragg Gratings, spatially distributed along its longitudinal extension is configured for insertion into an artery (AT). A temperature changer (TC) is arranged in the WD to introduce a local change in temperature (ΔT) of a bolus of blood in the artery, to allow thermal tracking over time with the optical fiber (FB). A measurement unit (MU) with a laser light source (LS) delivers light to the optical fiber (FB) and receives light reflected from the optical fiber (FB) and generates a corresponding time varying output signal. A first algorithm (A1) translates this time varying output signal into a set of temperatures corresponding to temperatures at respective positions along the optical fiber (FB). A second algorithm (A2) calculates a measure of blood flow (BF) at respective positions along the optical fiber (FB) in accordance with a temporal behavior of said set of temperatures. Such system can be used to quickly scan an artery for diagnosing stenotic regions without the need for pullbacks or injection of toxic liquids. A good spatial resolution of the blood flow measurement can be obtained in real-time.