US 5,966,169 AGranted

Three dimensional beamformed television

OwnerJames K. Bullisinventor

Life of this patent

Estimating the term…

Loading patent…

Abstract

The system provides three-dimensional real time imaging, with features that serve to control acoustic effects that cause interference. Systems are disclosed for medical imaging and other applications in fields that utilize radiated wave signals. The system includes visualization methods to enable guidance of surgical instruments as well as general medical diagnostic usage. The present invention uses a beamformed television method which achieves visual format imaging. Beamformed television includes orthogonal arrays to efficiently resolve two dimensions of a scene with measures to control grating lobes. Beamformed television also includes a method that reduces the time to transmit and receive signals by use of a single burst transmission of multiple frequency codes from each transducer which causes multiple, coded transmit beams that are radiated simultaneously. The addition of step chirp operations achieves highly precise range resolution which makes visual format imaging possible at selected ranges. It also enables a variety of visualization capabilities. The step chirp operation involves repeating the burst transmission at sequentially stepped frequencies. Thus, the frequency codes, that enable the transmit beamforming process, are shifted as a group for each frequency step of the stepped chirp. Frequency domain to time domain conversion using an FFT method efficiently yields range resolved signals.

Claims50

Dependent claims

An imaging apparatus comprising:

(a) a plurality of transmitting transducers in a transmitting array having a plurality of dimensions where said transmitting transducers simultaneously transmit radiated signals, and said radiated signals are radiated over a common field of view wherein objects modify said radiated signals to cause reflected signals, and
(b) signal means of coding, phase adjusting, and distributing transmit signals that drive said transmitting transducers such that radiated signals form into a plurality of simultaneous, coded transmit beams that serve to identify transmit regions of said common field of view, by respective codes of said coded transmit beams passing through respective said transmit regions, and said coded transmit beams are simultaneously produced by a single burst transmission, where codes used are discrete frequency codes, and
(c) a plurality of receiving transducers in a receiving array having a plurality of dimensions where said receiving transducers simultaneously sense said reflected signals, and thereby produce received signals, and
(d) signal means of combining signals to form virtually simultaneous receive beam channels that are associated with respective receive regions, and signal means of processing signals to separate coded signals such that virtually simultaneous code channels are formed where said code channels are associated with respective said coded transmit beams, such that for a receive beam there is a plurality of said code channels, and
(e) said transmitting array and said receiving array are relatively oriented to enable said transmit regions and said receive regions to determine location of said objects in two dimensions, and
(f) signal means of frequency adjusting said transmit signals, and a sequence of operations such that said single burst transmission is repeated with said discrete frequency codes at successively different, respective, frequency values, and
(g) signal means of performing transform operations to process signals resulting from said sequence of operations to form range increment channels that are associated with range increments, and
(h) signal means of processing signals such that a combination of said range increments, said transmit regions, and said receive regions determine location of said objects in three dimensions, and
(i) signal means of processing signals to form image signals.

6 more elements

A sensing system comprising:

(a) a plurality of transmitting transducers in a transmitting array having a plurality of dimensions where said transmitting transducers simultaneously transmit radiated signals, and said radiated signals are radiated over a common field of view wherein objects modify said radiated signals to cause reflected signals, and
(b) signal means of coding, phase adjusting, and distributing transmit signals that drive said transmitting transducers such that radiated signals form into transmit beams and transmit beams pass through respective said transmit regions, and
(c) a plurality of receiving transducers in a receiving array having a plurality of dimensions where said receiving transducers simultaneously sense said reflected signals, and thereby produce received signals, and
(d) signal means of combining signals to form receive beam channels that are associated with respective receive regions, and
(e) said transmitting array and said receiving array are relatively oriented to enable said transmit regions and said receive regions to determine location of said objects in two dimensions, and
(f) signal means of frequency adjusting said transmit signals, and a sequence of operations such that said transmit signals are repeated at successively different frequency values, and
(g) signal means of performing transform operations to process signals resulting from said sequence of operations to form range increment channels that are associated with range increments, and
(h) an efficient distribution of elements in an array that causes grating lobe effects, and said grating lobe effects are suppressed by directional effects of a different array, and
(i) signal means of processing signals such that a combination of said range increments, said transmit regions, and said receive regions determines location of said objects in three dimensions, and
(j) signal means of processing signals to form sensing signals.

7 more elements

Dependencies are inferred from the claim text.