Abstract: The present invention is directed to apparatuses and methods for determining blood flow characteristics and imaging interior surface contours within vessel walls. In a preferred embodiment, the method of the invention includes a hollow tubular lumen having a proximal end and distal end wherein the distal end includes a microbubble forming arrangement for forming microbubbles when a gas is passed through the distal end of the hollow tube.

Abstract: In a cardiac assist device, a housing has an inlet and outlet connectable to a patient's cardiovascular system. A pump is located within the housing to force blood that has entered through the inlet out through the outlet. The pump is connectable between the patient's left atrium and the aorta so as to assist the function of the left ventricle. A motor unit is also disposed within the housing, hermetically sealed from the pump. The whole unit is wholly implantable in a patient's chest. Permanently sealable valves, disposed in the inlet and outlet, may be closed without any invasive procedure to isolate the device from the heart once cardiac function assist is no longer required. The device may remain implanted within the patient indefinitely after the valves have been closed, and there is no requirement for a surgical procedure to remove the device once it is de-activated.

Abstract: A device for marking a planned guide path of a medical instrument such as a puncture needle is disclosed. The device incorporates two sources of electromagnetic radiation, such as lasers, which produce two light rays. The intersecting line of the light rays marks the guide path for the puncture needle. Deviations of the angle position of the puncture needle from the planned guide path are visible by examining the reflection of the light from the puncture needle. Different colors of light may be used with the light rays being formed in a fan-shape in a common plane. In this manner, the color of the reflected light on the surface of the puncture needle changes depending on whether the puncture needle is located at the intersection of the light rays.