NON-COHERENT FREQUENCY SOURCE AND SECTOR SCANNING APPARATUS FOR ULTRASONIC IMAGING SYSTEM USING A LIQUID CRYSTAL DETECTOR CELL

• Main Author: SANDHU, JASWINDER S
• Format: Patent
• Language: English; French
• Published: 21.03.1989
• Edition: 4
• Subjects: ACOUSTICS; ACOUSTICS NOT OTHERWISE PROVIDED FOR; ANALOGOUS ARRANGEMENTS USING OTHER WAVES; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; DEVICES OR ARRANGEMENTS, THE OPTICAL OPERATION OF WHICH ISMODIFIED BY CHANGING THE OPTICAL PROPERTIES OF THE MEDIUM OF THEDEVICES OR ARRANGEMENTS FOR THE CONTROL OF THE INTENSITY,COLOUR, PHASE, POLARISATION OR DIRECTION OF LIGHT, e.g.SWITCHING, GATING, MODULATING OR DEMODULATING; DIAGNOSIS; FREQUENCY-CHANGING; HUMAN NECESSITIES; HYGIENE; IDENTIFICATION; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION ORRERADIATION OF RADIO WAVES; MEASUREMENT OF MECHANICAL VIBRATIONS OR ULTRASONIC, SONIC ORINFRASONIC WAVES; MEASURING; MEDICAL OR VETERINARY SCIENCE; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING,NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; MUSICAL INSTRUMENTS; NON-LINEAR OPTICS; OPTICAL ANALOGUE/DIGITAL CONVERTERS; OPTICAL LOGIC ELEMENTS; OPTICS; PHYSICS; RADIO DIRECTION-FINDING; RADIO NAVIGATION; SOUND-PRODUCING DEVICES; SURGERY; TECHNIQUES OR PROCEDURES FOR THE OPERATION THEREOF; TESTING

There is disclosed herein an ultrasonic imaging system using a liquid crystal detector cell and a source of non-coherent acoustic energy to produce substantially artifact-free images. The ultrasound source and cell are matched with one another, and the source is caused to operate over a range of frequencies or phases so as to produce the non-coherent ultrasonic energy. The frequency response of the cell and its response time are matched to the operating characteristics of the transducer. The transducer may be mounted in a pendulum-like sector scanning apparatus so as to assure a uniform insonification of the object, a uniform beam and a substantially uniform non-coherent insonification of the cell. The movement of the scanning apparatus is also matched to the cell and transducer characteristics.