Interspec, Inc.

Imaging Associates

Saleem Kassam

Ajay K Luthra

Richard B Bernardi

J William Mauchly

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. The resulting image is as if the energy projected upon the body had been formed into a scanning beam which is continuously focused in range at all points in the field of view.

Body imaging using vectorial addition of acoustic reflection to achieve

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. The plurality of the stored signals from each subarray, which may be termed 'complex image' signals, are then vectorially added and further processed to derive a video signal which is used to produce a final display image.

Growing community of inventors

Bala Cynwyd, PA, United States of America

Saleem Kassam