Abstract:
An ultrasonic diagnostic system is provided which automatically sets up the TGC characteristic to be used for a given ultrasound examination. Upon user selection of a particular ultrasound application, a setup controller accesses a predetermined TGC characteristic for the selected application. The predetermined TGC characteristic is used to control the gain of a TGC amplifier and is also displayed to the user. By adjustment of a series of TGC controls the user can vary the TGC characteristic from the predetermined characteristic.
Abstract:
An ultrasonic diagnostic imaging system is provided for scanning with a linear transducer array and displaying an image area which is truncated with respect to a conventional triangular image sector to take the form of a trapezoid. Uniformity of image resolution and ease of signal processing enhancement is provided by transmitting adjacent ultrasonic beams at equal angular increments over the sector area. The ultrasonic beams transmitted are focused around predetermined transmit focal points and the transmit aperture employed for each transmission is determined by a transducer sensitivity criterion applied to the focal point. Means are provided for delaying signal components received from the beam directions so that the sum of the components will form a coherent echo signal. Means are provided for dynamically focusing received signal components by dynamically focusing received signal components by dynamically varying the sampling frequencies of laterally disposed signal components, and the receive aperture is dynamically varied in correspondence with the number of array elements which satisfy a sensitivity criterion at different depths of field.
Abstract:
An abrasive tipped rotating cutting tool (10) for use in removing abnormal deposits within a patient's vessels is described. The tip (12) is preferably covered with a material such as diamond grit, and rotated at high speed to pulverize any abnormal deposits contained within the vessel.
Abstract:
The transducer of the present invention is diced into subelements which have a height-to-width ratio which determines the modality of their vibration. The subelements are then electrically connected to provide a transducer having the desired electrical configuration, i.e., an annular array transducer. Using the present invention, the electro-acoustic characteristics of the transducer are not determinitive of the vibrational characteristics of the individual subelements.
Abstract:
The invention is an apparatus for breaking up a thrombus by introducing a rotating drive shaft (14) into the thrombus whereby the fibrin of the thrombus will be withdrawn from the thrombus onto the rotating drive shaft (14), thereby breaking up the network of the thrombus which prevents blood flow. The apparatus includes a drive shaft housing (16) which can be used to withdraw fluid from the area of the thrombus or to introduce enzymes, such as streptokinase which will further break up the thrombus or contrast agent for visualizing the vascular anatomy.
Abstract:
The invention is a fiber-optic endoscope which has an elongated ultrasonic array such as a linear array or a phased array. The array is mounted on either the distal portion of the bending section (not under operator control) portion of the endoscopic tube or on the proximal portion of bendable portion of the tube. Thus, the present invention includes both a fiber-optic endoscope and an ultrasonic transducer. Yet, the presence of the ultrasonic transducer does not interfere with the operation of the placement of the fiber-optic probe.
Abstract:
A digital scan converter is disclosed wherein signal information supplied by a sector scanning surveillance system relative to a polar coordinate system is converted to a signal for driving a television-type display or other Cartesian coordinate device by: (a) sampling the signal associated with each consecutive scanning path of the surveillance system at a rate determined by the azimuthal angle that defines the scanning path of interest; (b) storing each set of signal samples as a column of data in a rectangular memory array: (c) accessing the stored data on a row-by-row basis; and (d) utilizing a previously determined mapping strategy to cause each accessed signal sample to form a segment of a line of display within the Cartesian-formulated display devices so that the length of the segment formed by each signal sample is determined by the row and column address of the storage location that is associated therewith when forming a television compatible signal, each signal sample dictates video signal level during a portion of a corresponding horizontal sweep period that is determined by the mapping strategy.