New

guide is flexible and steerable for precise place- ment. The wire guide includes an elongated wire member having a Doppler crystal attached in longitudinal alignment at its distal end. Elec- trical leads extend from the Doppler crystal along the wire member to the appropriate test equipment for measuring the fluid flow velocity in the region of the Doppler crystal. Preferred embodiments of the Doppler means include piezoelectric crystals and piezoelectric polymers. Also disclosed is a guide wire with a laser Dop- pler means.

4921476

M E T H O D F O R P R E V E N T I N G C L O G G I N G O F A S U R G I C A L

A S P I R A T O R

David Wuchinich assigned to Cavitron Inc

The method of aspirating body tissue and blood from a surgical site along a suction passage having a suction port at an ultrasonically vibrated end of a tool for fragmenting the tissue at a surgical site is improved by introducing an irrigation fluid into the suction passage indepen- dently of the suction port.

Patents 415

of the series of unity matrix products relative to said selected principal vectors.

4922902

M E T H O D F O R R E M O V I N G C E L L U L A R M A T E R I A L W I T H E N D O S C O P I C U L T R A S O N I C

A S P I R A T O R

David G Wuchinich, Donald R Krawitt, Robert Brendolan, Louis Katz assigned to Valleylab Inc

A method and apparatus for endoscopic removal of compliant biological tissues utilizing an endoscopic ultrasonic aspirator comprising irrigation and aspiration means, a piezoelectric ultrasonic transducer, a first resonator such as a half-wave stepped velocity transformer, a probe including a second resonator such as a constant- stress velocity transformer, a blunt or modified working tip of open channel means or restricted tubular means for application of ultrasonic energy to cellular material, and a capacitive fluid sensor to detect the presence of irrigation fluid adjacent these transformers within the instru- ment. The surgery is advantageously performed by operating the transducer in the 10-20 kHz range to achieve maximum cavitation of the intracellular fluids in the tissues to be removed.

4922422

M E T H O D A N D A P P A R A T U S F O R S E L E C T I V E S U P P R E S S I O N O F

P O R T I O N S O F AN E C H O G R A P H I C S I G N A L T O

I M P R O V E I M A G E R E C O N S T R U C T I O N

Jean Pergrale, Paris, France assigned to U S Philips Corporation

A method of scanning objects by means of ul- trasonic echography, including the transmission of ultrasonic waves to the object to be scanned by means of a transducer array (101) and the recep- tion and processing of the echographic signals corresponding to the echoes returned. Digitized A-lines are divided into n elements of p points and, after various operations, the reconstruction of the elements of the echographic lines by selec- tion of principal vectors which imply factors which imply a reconstruction of the matrix sum

4922917

U L T R A S O N I C T I S S U E C H A R A C T E R I Z A T I O N

Jacques Dory, Coupvray Esbly, France assigned to EDAP International

A tissue characterization device is provided comprising means for transmitting high carrier frequency ultrasonic pulses to the tissues, means for receiving and converting the echos into high frequency electric signals and means for storing said electric signals with a sampling frequency sufficient for the high frecluency information which they contain to be correctly recorded, fur- ther comprising means for reading the stored in- formation at a rate less than the sampling frequency and such that the high frequency spectrum is transposed into the range of audible frequencies and means for converting the trans- posed spectrum into a sound signal.