New Patents

ments of a linear transducer array are altered by collimation of ultrasonic waves using critical angle effects. A phased array transducer for a medical imaging system with a 90 degrees image sensor has a collimator which is a thin sheet of polyethylene. Acoustic waves whose angle of in- cidence is greater than the critical angle are totally reflected. Insignificant ultrasonic energy is generated outside of the imaged sector and there is a modest insertion loss over the ac- ceptance region.

4442715

VARIABLE FREQUENCY ULTRASONIC SYSTEM

Axe1 F Brisken, Lowell S Smith assigned to General Electric Company

The ultrasonographer changes the frequency of ultrasound pulses emitted from an ultrasonic transducer as a result of adjusting the RF fre- quency of the transmitter burst exciting the broadband transducer; this adjustment takes place between pulse transmissions, while ex- amining the patient. In a phased array imager utilizing baseband processing of received echo signals, the same adjustment supplies the cor- responding frequency to the demodulator cir- cuits. An alternative method of changing the system spectrum is to have a narrow bandwidth receiver whose center frequency is varied over the available bandwidth.

4444197

ULTRASONIC DIAGNOSTIC PROBE SCANNER

Akir Koyano, Seiichiro Mizuno, Tokyo, Japan assigned to Aloka Co Ltd

An ultrasonic diagnostic probe scanner for an ultrasonic diagnostic apparatus. The scanner in- cludes a scanner system having six joints, each of which can be rotated within a predetermined plane. The scanner system is supported on a scanner base at one end and has an ultrasonic probe attached thereto at the other end. Each of the six joints is provided with an angle detector to detect the angle of the joint. As a result, the ul- trasonic probe can be arbitrarily positioned with an arbitrary beam direction. The positional in- formation obtained from the angle detectors is used to provide the ultrasonic diagnostic ap- paratus with additional functions.

4445379

APPARATUS FOR RECEIVING REFLECTED ULTRASONIC

WAVES IN ULTRASONOGRAPHY

Keiki Yamaguchi, Yasuhit Takeuchi, Shinichi Sano, Taka Higashiizumi, Tokyo, Japan as- signed to Yokogawa Hokushin Electric Cor- poration

An echo signal receiver receives higher level echo signals reflected from strong reflections sources