Saleem A Kassam

45534373, Nov 19, 1985

Jan 30, 1984

6/574883

Ajay K. Luthra - Bala Cynwyd PA
Saleem Kassam - Bala Cynwyd PA
J. William Mauchly - Ambler PA

Imaging Associates - Villanova PA

G01N 2904

73602

Certain ones of a total array of ultrasonic transducers constitute a small aperture and are so energized as to project acoustic energy onto predetermined parts of a scene. Reflections of the transmitted signals are received by certain ones of the array, are converted to electrical signals and are appropriately delayed to enable additive combination of the amplitude of the received signals emanating from the same points in the scene ("targets"). The phase (or time delay) as well as the amplitude information of the reflective signals are stored. Next, the same transmitting elements ("subarray") project acoustic energy upon the remaining parts of the scene in sequence and the reflected signals are similarly processed and stored. This continues until all the parts of the predetermined scene have been interrogated by insonification from that subarray and the reflected signals have been similarly processed. Then, at least one more set of transducers of the total array, which also constitute a small aperture, are caused to scan the same parts of the image in the same sequence thereby producing the same types of reflected signals which are processed similarly, and whose amplitude and phase information is similarly stored.

46046976, Aug 5, 1986

Aug 5, 1983

6/520573

Ajay K. Luthra - Bala Cynwyd PA
Saleem Kassam - Bala Cynwyd PA
Richard B. Bernardi - Strafford PA

Interspec, Inc. - Conshohocken PA

G01N 2900

364414

An array of acoustic transmit/receive transducers is placed near the body to be imaged. Acoustic energy is projected upon the body sequentially from different ones of the transducers, each projection covering the entire scene or field of view which it is desired to image. The electrical signals produced from reflected acoustic energy picked up by different transducers are phase shifted, or time delayed as appropriate, so that those from any particular point within the body will additively combine in amplitude, while signals from other points will not. In so doing, there is preserved not only the information about the amplitude of the combined signal from the transducers, but also any information about phase shifts (or time delays as the case may be) which does not result in complete alignment of the signals from the different transducers. The resulting complex signals are further processed, to vectorially add them. The signals produced by this further vectorial addition are then used for the visual display of the image.

52787575, Jan 11, 1994

Nov 15, 1991

7/792789

Ralph T. Hoctor - Wilmington DE
Saleem A. Kassam - Bala Cynwyd PA

The Trustees of The University of Pennsylvania - Philadelphia PA

G06F 1500
G01N 2900

36441325

A synthetic aperture ultrasonic imaging system for imaging a target with a resolution limited by a designated aperture. A phased array of nonuniformly spaced ultrasound transducers having an average inter-transducer spacing which is greater than a. lambda. /2 Nyquist spacing for the transducers is used for imaging in a manner so as to either obtain a desired point spread function which is unattainable by a single image taken by the nonuniformly spaced transducers or to provide coarray equivalence to a phased array of transducers which are uniformly spaced at the. lambda. /2 Nyquist spacing for the designated aperture. Coarray equivalence makes possible the technique of applying amplitude weightings to each of the nonuniformly spaced ultrasound transducers during transmit and receive modes and by forming a number of component images which when added together form a sum image substantially equivalent to a single image formed by a scan beam of the uniformly spaced transducers with the designated aperture. The complex values of the resulting component images are then added on a point by point basis, preserving phase, such that a point spread function of the sum image is substantially equivalent to the desired point spread function of the single image formed by the uniformly spaced transducers with the designated ape STATEMENT OF GOVERNMENT INTEREST This invention was made with government support under contract N00014-89-J-1538 awarded by the Department of the Navy. The government has certain rights in the invention.