ULTRASONIC BLOOD VOLUME FLOW RATE METER

摘要

A volume flow meter for displaying two-dimensional volume flow through a vessel, comprising an ultrasound instrument with scan head, a location and orientation sensor mounted to the scan head, and a computer connected to the ultrasound instrument and the sensor. The scan head is adapted to be positioned adjacent the vessel under investigation, for generating a raster of pixels which defines a colour image representing flow velocities in the vessel through an image plane of the scan head. The sensor measures position and orientation of the scan head in three dimensions and generates a signal representative thereof to the computer. The computer receives said raster of pixels and the signal from the sensor and in response calculates the position and orientation of the vessel axis in three-dimensions responsive to orientation of the image plane longitudinally of the vessel. The computer then determines an angle ? between this axis and the image plane responsive to orientation of the image plane transversally to the vessel. Finally, the computer calculates and displays the volume flow as a summation of the flow velocities scaled by the tangent of the angle ?.