EP0256686A1 — Method and apparatus for measuring ultrasonic vel…

Claim 1

Independent Claim 165 words

A method for measuring an ultrasonic velocity (C O ) in a region of interest (ROI) within a medium (54; 201) by exciting transducer means (10; 330), said transducer means (10; 330) including a plurality of transducer elements arranged in an array form which are subdivided into at least first and second transmitter sections (11; 12; 202; 203; 331; 334) and first and second receiver sections (13; 14; 204; 205; 332; 333), characterized by comprising the steps of: exciting said first and second transmitter sections (11; 12; 202; 203; 331; 334) to transmit first and second ultrasonic beams toward said ROI, said first ultrasonic beam being intersected by said second ultrasonic beams within said ROI; receiving ultrasonic echoes reflected from said ROI by operating said first and second receiving sections (13; 14; 204; 205; 332; 333) to produce echo signals; and processing said echo signals to obtain propagation time of said ultrasonic beams and said ultrasonic velocity within said ROI based upon said propagation time.

Claim 2

Independent Claim 165 words

A method for measuring an ultrasonic velocity (C O ) in a region of interest (ROI) within a medium (54; 201) by exciting transducer means (10; 330), said transducer means (10; 330) including a plurality of transducer elements arranged in an array form which are subdivided into at least first and second transmitter sections (11; 12; 202; 203; 331; 334) and first and second receiver sections (13; 14; 204; 205; 332; 333), characterized by comprising the steps of: exciting said first and second transmitter sections (11; 12; 202; 203; 331; 334) to transmit first and second ultrasonic beams toward said ROI, said first ultrasonic beam being intersected by said second ultrasonic beams within said ROI; receiving ultrasonic echoes reflected from said ROI by operating said first and second receiving sections (13; 14; 204; 205; 332; 333) to produce echo signals; and processing said echo signals to obtain propagation time of said ultrasonic beams and said ultrasonic velocity within said ROI based upon said propagation time.

Claim 3

Dependent Claim 61 words

A method as claimed in claim 1, characterized in that said processing step includes the steps of: adding said echo signals with each other to derive a single synthesized echo signal; envelope-detecting said single synthesized echo signal to produce an envelope-detected echo signal; and, calculating said envelope-detected echo signal to finally obtain said ultrasonic velocity (C O ) within said ROI.

Claim 4

Dependent Claim 56 words

A method as claimed in claim 1, characterized in that said processing step includes the steps of: envelope-detecting said echo signals to produce detected echo signals; adding said detected echo signals with each other to produce a single synthesized echo signal; and, calculating said synthesized echo signal to finally obtain said ultrasonic velocity within said ROI.

Claim 5

Independent Claim 218 words

An apparatus (100) for measuring an ultrasonic velocity (C O ) in a region of interest (ROI) within a medium (54) by utilizing plural ultrasonic beams characterized by comprising: transducer means (10) including a plurality of transducer elements arranged in an array form, which are subdivided into at least first and second transmitter sections (11; 12) and first and second receiver sections (13; 14), said sections being arranged in the other of transmitter-receiver-receiver-transmiter sections (11; 12; 13; 14), and being located at predetermined distances, and each of said first and second transmitter and receiver sections (11; 12; 13; 14) being constructed of a plurality of transducer elements; driver means (21; 22; 23) for driving said first and second transmitter sections (11; 12) to transmit first and second ultrasonic beams respectively to said ROI, said first ultrasonic transmit beam being intersected by said second ultrasonic transmit beam within said ROI; receiver means (25) coupled to said first and second receiver sections (13; 14), for receiving ultrasonic echoes reflected from said ROI to produce echo signals; and, processor means for processing said echo signals to calculate propagation time of said ultrasonic beams and said ultrasonic velocity (C O ) within said ROI based upon said calculated propagation time and said distance between said first and second receiver sections (13; 14).

Claim 6

Independent Claim 218 words

An apparatus (100) for measuring an ultrasonic velocity (C O ) in a region of interest (ROI) within a medium (54) by utilizing plural ultrasonic beams characterized by comprising: transducer means (10) including a plurality of transducer elements arranged in an array form, which are subdivided into at least first and second transmitter sections (11; 12) and first and second receiver sections (13; 14), said sections being arranged in the other of transmitter-receiver-receiver-transmiter sections (11; 12; 13; 14), and being located at predetermined distances, and each of said first and second transmitter and receiver sections (11; 12; 13; 14) being constructed of a plurality of transducer elements; driver means (21; 22; 23) for driving said first and second transmitter sections (11; 12) to transmit first and second ultrasonic beams respectively to said ROI, said first ultrasonic transmit beam being intersected by said second ultrasonic transmit beam within said ROI; receiver means (25) coupled to said first and second receiver sections (13; 14), for receiving ultrasonic echoes reflected from said ROI to produce echo signals; and, processor means for processing said echo signals to calculate propagation time of said ultrasonic beams and said ultrasonic velocity (C O ) within said ROI based upon said calculated propagation time and said distance between said first and second receiver sections (13; 14).

Claim 7

Dependent Claim 104 words

An apparatus (100) as claimed in claim 4, characterized in that said processor means calculates the following equation to obtain said ultrasonic velocity (C O ) within said ROI: where "dp" is said distance between the first and second receiving sections (13; 14), "At * " denotes a propagation time difference between said first and second ultrasonic beams transmitted from said first and second transmitter sections (11; 12) and received by said first and second receiver sections (13; 14), and "a" is defined by a ratio of a delay time given to said transducer element to said predetermined distance between said succeeding transducer elements.

Claim 8

Dependent Claim 67 words

An apparatus (100) as claimed in claim 4, characterized in that said processor means includes: an adder (26) for adding said echo signals to produce a single synthesized echo signal; a detector (27) for envelope-detecting said synthesized echo signal to derive an envelope-detected echo signal; and a calculator (30) for calculating said envelope-detected echo signal to finally obtain said ultrasonic velocity (C O ) within said ROI.

Claim 9

Dependent Claim 38 words

An apparatus (100) as claimed in claim 6, characterized in that said calculator (30) calculates said propagation time from said envelope-detected echo signal based upon a method of measuring a center of gravity of said envelope-detected echo signal.

Claim 10

Dependent Claim 51 words

An apparatus (100) as claimed in claim 4, characterized by further comprising: a logarithmic amplifier (31) for logarithmic- amplifying said echo signals derived from said receiver means (13; 14); and a detector (32) for detecting said logarithmic- amplified echo signals to produce an ultrasonic tomographic image signal of said medium (54).

Claim 11

Dependent Claim 42 words

An apparatus (100) as claimed in claim 4, characterized in that said first and second receiver sections (13; 14) are located inside said first and second transmitter sections (11; 12) along a longitudinal direction of the array of said transducer means (10).

Claim 12

Independent Claim 236 words

An apparatus (200; 300; 400) for measuring an ultrasonic velocity in a region of interest (ROI) within a medium (201) by utilizing plural ultrasonic beams, characterized by comprising: transducer means including a plurality of transducer elements arranged in an array form, which are subdivided into at least first and second transmitter sections (202; 203) and first and second receiver sections (204; 205), said sections being arranged in the order of transmitter-receiver-receiver-transmitter sections (11; 12; 13; 14), and being located at predetermined distances, and each of said first and second transmitter and receiver sections (202; 203; 204; 205) being constructed of a plurality of transducer elements; driver means (206; 211) for driving said first and second transmitter sections (202; 203) to transmit first and second ultrasonic beams respectively toward said ROI, said first ultrasonic beam being inte.rsected by said second ultrasonic beam within said ROI; detector (208) means coupled to said first and second receiver sections (204; 205) for envelope-detecting ultrasonic echoes reflected from four corners (J; K; L; M) of said ROI to produce four detected echo signals; adder means (209) for adding said detected echo signals to produce a single synthesized echo signal; and calculator means (212) for calculating from said synthesized echo signal, propagation time of said ultrasonic beams and said ultrasonic velocity within said ROI based upon said calculated propagation time and said distance between said first and second receiver sections (204; 205).

Claim 13

Independent Claim 236 words

An apparatus (200; 300; 400) for measuring an ultrasonic velocity in a region of interest (ROI) within a medium (201) by utilizing plural ultrasonic beams, characterized by comprising: transducer means including a plurality of transducer elements arranged in an array form, which are subdivided into at least first and second transmitter sections (202; 203) and first and second receiver sections (204; 205), said sections being arranged in the order of transmitter-receiver-receiver-transmitter sections (11; 12; 13; 14), and being located at predetermined distances, and each of said first and second transmitter and receiver sections (202; 203; 204; 205) being constructed of a plurality of transducer elements; driver means (206; 211) for driving said first and second transmitter sections (202; 203) to transmit first and second ultrasonic beams respectively toward said ROI, said first ultrasonic beam being inte.rsected by said second ultrasonic beam within said ROI; detector (208) means coupled to said first and second receiver sections (204; 205) for envelope-detecting ultrasonic echoes reflected from four corners (J; K; L; M) of said ROI to produce four detected echo signals; adder means (209) for adding said detected echo signals to produce a single synthesized echo signal; and calculator means (212) for calculating from said synthesized echo signal, propagation time of said ultrasonic beams and said ultrasonic velocity within said ROI based upon said calculated propagation time and said distance between said first and second receiver sections (204; 205).

Claim 14

Dependent Claim 116 words

An apparatus (200) as claimed in claim 10, characterized in that said calculator means (212) calculates the following equation to obtain said velocity (C O ) within said ROI: where "do" is said distance between the first and second receiving sections (204; 205), "At" represents a propagation time difference between said first and second ultrasonic beams transmitted from said first and second transmitter sections (202; 203) and received by said first and second receiver sections (204; 205), and "6 0 " is defined by an angle of one of said first and second ultrasonic beams incident upon said ROI with respect to a receiving direction of one of said first and second receiving sections (204; 205).

Claim 15

Dependent Claim 69 words

An apparatus (200) as claimed in claim 10, characterized by further comprising: first switching means (216-1) for selectively coupling said driving means (206; 211) to said first and second transmitter sections (202; 203) so as to selectively excite said transmitter sections (202; 203); and, second switching means (216-2) for selectively coupling said detector means (208) to said first and second receiver sections (204; 205) to receiver said ultrasonic echoes.

Claim 16

Dependent Claim 40 words

An apparatus (200; 300; 400) as claimed in claim 10, characterized in that said calculator (212) calculates said propagation time from said synthesized echo signal based upon a method of measuring a center of gravity of said synthesized echo signal.

Claim 17

Dependent Claim 39 words

An apparatus (200; 300; 400) as claimed in claim 10, characterized in that said calculator (212) calculates said propagation time from said synthesized echo signal based upon a method of measuring a peak value of said synthesized echo signal.

Claim 18

Dependent Claim 43 words

An apparatus (200; 300; 400) as claimed in claim 10, characterized in that said first and second receiver sections (204; 205) are located inside said first and second transmitter sections (202; 203) along a longitudinal direction of the array of said transducer means.

Claim 19

Dependent Claim 51 words

An apparatus (400) as claimed in claim 10, characterized by further comprising: a logarithmic amplifier (31) for logarithmic- amplifying said echo signals derived from said receiver means (332; 333); and, a detector (32) for detecting said logarithmic- amplified echo signals to produce an ultrasonic tomographic image signal of said medium (201).

Method and apparatus for measuring ultrasonic velocity in a medium by crossed beams

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