US5615675A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and system for 3-D acoustic microscopy using short pulse excitation and 3-D acoustic microscope for use therein
Assignee: University of Michigan (System)
•
Filing: 1996-04-19
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Granted: 1997-04-01
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Expires: 2016-04-19
Abstract
Abstract A method and system are provided for 3-D acoustic microscopy using short pulse laser excitation. A 3-D acoustic microscope for use in such a system is also provided. In a first embodiment, wherein optical detection is utilized, a focused excitation beam is scanned by a first acoustooptic scanning device across an absorbing layer of an opto-acoustic transducer (if needed) coupled to an object under investigation to create spherical ultrasonic waves within the object which may be living tissue. The reflected spherical ultrasonic waves are detected through the use of an unfocused probe beam and an optical detector array or a focused probe beam and a single photodetector which receive the probe beam from a reflecting surface of the opto-acoustic transducer. A second acoustooptic scanning device scans the probe beam at a plurality of positions on the reflecting surface of the opto-acoustic transducer. In another embodiment, an ultrasound transducer is utilized to acoustically detect the reflected spherical ultrasonic waves. Signals from the optical detector array, the photodetector, or the ultrasound transducer are subsequently digitized and reconstructed via 3-D synthetic aperture beam-forming equations to generate a 3-D representation of the object. Then the 3-D representation of the image is displayed as an image. The microscope includes the first and second acoustooptic scanning devices and the opto-acoustic transducer housed in a housing to define a needle probe such as a conventional biopsy needle.
Inventors
- 👤 Matthew O'Donnell
- 👤 James D. Hamilton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 21:30
CPC Classifications
G; G01; G01N; G01N29/00; G01N29/04; G01N29/06; G01N29/0654; G01N29/069; G01N29/0681; G01N29/22; G01N29/24; G01N29/2418; G01S; G01S15/00; G01S15/88; G01S15/89; G01S15/8906; G01S15/8965; G01N2291/00; G01N2291/02; G01N2291/024; G01N2291/02475; G01N2291/04; G01N2291/042; G01N2291/0421
Claims Analysis
Total Claims: 64
Claim 1
Independent Claim
127 words
A method for examining an object internally, the method comprising the steps of: positioning an opto-acoustic transducer having a reflecting surface and an absorbing layer capable of converting a burst of electromagnetic energy into a thermal pulse relative to the object so that the thermal pulse propagates as an acoustic wave in the object and is internally reflected within the object; scanning a plurality of bursts of the electromagnetic energy over a surface of the absorbing layer to obtain acoustic waves in the object; detecting acoustic waves reflected within the object at a plurality of positions on the reflecting surface of the opto-acoustic transducer to generate resultant signals; calculating a 3-D representation of the object from the resultant signals; and displaying the 3-D representation as an image.
Claim 2
Independent Claim
127 words
A method for examining an object internally, the method comprising the steps of: positioning an opto-acoustic transducer having a reflecting surface and an absorbing layer capable of converting a burst of electromagnetic energy into a thermal pulse relative to the object so that the thermal pulse propagates as an acoustic wave in the object and is internally reflected within the object; scanning a plurality of bursts of the electromagnetic energy over a surface of the absorbing layer to obtain acoustic waves in the object; detecting acoustic waves reflected within the object at a plurality of positions on the reflecting surface of the opto-acoustic transducer to generate resultant signals; calculating a 3-D representation of the object from the resultant signals; and displaying the 3-D representation as an image.
Claim 3
Dependent Claim
18 words
The method as claimed in claim 1 wherein the bursts of electromagnetic energy are pulses of laser light.
Claim 4
Dependent Claim
59 words
The method as claimed in claim 2 wherein the acoustic waves have a primary wavelength, λ, and wherein the method further comprises the step of focusing the pulses of laser light so that each thermal pulse is generated at an area of the absorbing layer approximately equal to λ 2 so that the acoustic sound waves are spherical waves.
Claim 5
Dependent Claim
31 words
The method as claimed in claim 1 wherein the bursts of electromagnetic energy are pulses of laser light and wherein the absorbing layer is a material layer of the opto-acoustic transducer.
Claim 6
Dependent Claim
20 words
The method as claimed in claim 4 wherein the absorbing layer of the opto-acoustic transducer is a thin metallic film.
Claim 7
Dependent Claim
38 words
The method as claimed in claim 5 wherein the opto-acoustic transducer includes an optically semi-transparent substrate layer having a thickness of approximately λ/4 and wherein the metallic film is formed as a surface layer on the substrate layer.
Claim 8
Dependent Claim
44 words
The method as claimed in claim 1 wherein the step of detecting includes the step of scanning the reflecting surface of the opto-acoustic transducer with a focused, continuous-wave laser beam operating at a wavelength different than the wavelength of the bursts of electromagnetic energy.
Claim 9
Dependent Claim
22 words
The method as claimed in claim 7 wherein the reflecting surface is a surface of the absorbing layer of the opto-acoustic transducer.
Claim 10
Dependent Claim
53 words
The method as claimed in claim 1 wherein the acoustic waves have a primary wavelength, λ, and wherein the step of detecting includes the step of scanning a probe beam having spot size with a diameter less than λ, over the reflecting surface of the opto-acoustic transducer at a plurality of scan positions.
Claim 11
Dependent Claim
20 words
The method as claimed in claim 1 wherein the step of detecting is accomplished with an array of opto-acoustic detectors.
Claim 12
Dependent Claim
70 words
The method as claimed in claim 1 wherein the acoustic waves have a primary wavelength, λ, and wherein the step of detecting is accomplished with an ultrasonic microscope transducer for focusing an acoustic spot on the surface of the object, the spot having an area approximately equal to λ 2 and wherein the microscope transducer is utilized to scan in a plane substantially parallel to the surface of the object.
Claim 13
Dependent Claim
20 words
The method as claimed in claim 1 wherein the step of calculating is based on 3-D synthetic aperture beam-forming equations.
Claim 14
Independent Claim
108 words
A method for examining an object internally, the object being capable of converting a burst of electromagnetic energy into a thermal pulse which propagates as an acoustic wave in the object and is internally reflected within the object, the method comprising the steps of: scanning a plurality of bursts of the electromagnetic energy over a surface of the object to generate acoustic waves in the object; detecting the acoustic waves reflected within the object at a plurality of positions on the surface of the object to generate resultant signals; calculating a 3-D representation of the object from the resultant signals; and displaying the 3-D representation as an image.
Claim 15
Independent Claim
108 words
A method for examining an object internally, the object being capable of converting a burst of electromagnetic energy into a thermal pulse which propagates as an acoustic wave in the object and is internally reflected within the object, the method comprising the steps of: scanning a plurality of bursts of the electromagnetic energy over a surface of the object to generate acoustic waves in the object; detecting the acoustic waves reflected within the object at a plurality of positions on the surface of the object to generate resultant signals; calculating a 3-D representation of the object from the resultant signals; and displaying the 3-D representation as an image.
Claim 16
Dependent Claim
18 words
The method as claimed in claim 13 wherein the bursts of electromagnetic energy are pulses of laser light.
Claim 17
Dependent Claim
58 words
The method as claimed in claim 14 wherein the acoustic waves have a primary wavelength, λ, and wherein the method further comprises the step of focusing the pulses of laser light so that each thermal pulse is generated at an area of the object approximately equal to λ 2 so that the acoustic sound waves are spherical waves.
Claim 18
Dependent Claim
42 words
The method as claimed in claim 13 wherein the step of detecting includes the step of scanning the surface of the object with a focused, continuous-wave laser beam operating at a wavelength different than the wavelength of the bursts of electromagnetic energy.
Claim 19
Dependent Claim
51 words
The method as claimed in claim 13 wherein the acoustic waves have a primary wavelength, λ, and wherein the step of detecting includes the step of scanning a probe beam having spot size with a diameter less than λ, over the surface of the object at a plurality of scan positions.
Claim 20
Dependent Claim
20 words
The method as claimed in claim 17 wherein the step of detecting is accomplished with an array of opto-acoustic detectors.
Claim 21
Dependent Claim
69 words
The method as claimed in claim 17 wherein the acoustic waves have a primary wavelength, λ, and wherein the step of detecting is accomplished with an ultrasonic microscope transducer for focusing an acoustic spot on the surface of the object, the spot having an area approximately equal to λ 2 and wherein the transducer is utilized to scan in a plane substantially parallel to the surface of the object.
Claim 22
Dependent Claim
20 words
The method as claimed in claim 17 wherein the step of calculating is based on 3-D synthetic aperture beam-forming equations.
Claim 23
Independent Claim
143 words
A system for examining an object internally, the system comprising: an opto-acoustic transducer adapted to be acoustically coupled to the object and having a reflecting surface and an absorbing layer capable of converting a burst of electromagnetic energy into a thermal pulse so that the thermal pulse propagates as an acoustic wave in the object and is internally reflected within the object; an excitation beam scanner for scanning a plurality of bursts of the electromagnetic energy over a surface of the absorbing layer to obtain acoustic waves in the object; a detector for detecting the acoustic waves reflected within the object at a plurality of positions on the reflecting surface of the opto-acoustic transducer to generate resultant signals; a calculator for calculating a 3-D representation of the object from the resultant signals; and a display for displaying the 3-D representation as an image.
Claim 24
Independent Claim
143 words
A system for examining an object internally, the system comprising: an opto-acoustic transducer adapted to be acoustically coupled to the object and having a reflecting surface and an absorbing layer capable of converting a burst of electromagnetic energy into a thermal pulse so that the thermal pulse propagates as an acoustic wave in the object and is internally reflected within the object; an excitation beam scanner for scanning a plurality of bursts of the electromagnetic energy over a surface of the absorbing layer to obtain acoustic waves in the object; a detector for detecting the acoustic waves reflected within the object at a plurality of positions on the reflecting surface of the opto-acoustic transducer to generate resultant signals; a calculator for calculating a 3-D representation of the object from the resultant signals; and a display for displaying the 3-D representation as an image.
Claim 25
Dependent Claim
18 words
The system as claimed in claim 21 wherein the bursts of electromagnetic energy are pulses of laser light.
Claim 26
Dependent Claim
60 words
The system as claimed in claim 22 wherein the acoustic waves have a primary wavelength, λ, and wherein the system further comprises an optical component for focusing the pulses of laser light so that each thermal pulse is generated at an area of the absorbing layer approximately equal to λ 2 so that the acoustic sound waves are spherical waves.
Claim 27
Dependent Claim
20 words
The system as claimed in claim 23 wherein the absorbing layer of the opto-acoustic transducer is a thin metallic film.
Claim 28
Dependent Claim
38 words
The system as claimed in claim 24 wherein the opto-acoustic transducer includes an optically semi-transparent substrate layer having a thickness of approximately λ/4 and wherein the metallic film is formed as a surface layer on the substrate layer.
Claim 29
Dependent Claim
31 words
The system as claimed in claim 21 wherein the bursts of electromagnetic energy are pulses of laser light and wherein the absorbing layer is a material layer of the opto-acoustic transducer.
Claim 30
Dependent Claim
28 words
The system as claimed in claim 26 further comprising an optical fiber and wherein the probe beam is delivered to the probe beam scanner by the optical fiber.
Claim 31
Dependent Claim
44 words
The system as claimed in claim 21 wherein the detector includes a probe beam scanner for scanning the reflecting surface of the opto-acoustic transducer with a focused, continuous-wave laser beam operating at a wavelength different than a wavelength of the bursts of electromagnetic energy.
Claim 32
Dependent Claim
22 words
The system as claimed in claim 28 wherein the reflecting surface is a surface of the absorbing layer of the opto-acoustic transducer.
Claim 33
Dependent Claim
53 words
The system as claimed in claim 21 wherein the acoustic waves have a primary wavelength, λ, and wherein the detector includes a probe beam scanner for scanning a probe beam having spot size with a diameter less than λ, over the reflecting surface of the opto-acoustic transducer at a plurality of scan positions.
Claim 34
Dependent Claim
20 words
The system as claimed in claim 30 wherein at least one of the scanners includes an electronically driven acoustooptic device.
Claim 35
Dependent Claim
15 words
The system as claimed in claim 31 wherein the acoustooptic device is a Bragg cell.
Claim 36
Dependent Claim
39 words
The system as claimed in claim 30 wherein the opto-acoustic transducer including the absorbing layer and the reflecting surface, the probe beam scanner and the excitation beam scanner are housed in a housing to define an optical needle probe.
Claim 37
Dependent Claim
49 words
The system as claimed in claim 30 further comprising a single optical fiber and wherein the probe beam is delivered to the probe beam scanner, the excitation beam is delivered to the excitation beam scanner and a detecting beam is delivered to the detector by the single optical fiber.
Claim 38
Dependent Claim
28 words
The system as claimed in claim 21 further comprising an optical fiber and wherein the excitation beam is delivered to the excitation beam scanner by the optical fiber.
Claim 39
Dependent Claim
29 words
The system as claimed in claim 34 wherein the detector includes a photodetector array and wherein a detecting beam is returned to the photodetector array by the optical fiber.
Claim 40
Dependent Claim
16 words
The system as claimed in claim 21 wherein the detector includes an array of opto-acoustic detectors.
Claim 41
Dependent Claim
66 words
The system as claimed in claim 21 wherein the acoustic waves have a primary wavelength, λ, and wherein the detector includes an ultrasonic microscope transducer for focusing an acoustic spot on the surface of the object, the spot having an area approximately equal to λ 2 and wherein the microscope transducer is utilized to scan in a plane substantially parallel to the surface of the object.
Claim 42
Dependent Claim
26 words
The system as claimed in claim 21 wherein the calculator includes a programmed computer for computing the 3-D representation based on 3-D synthetic aperture beam-forming equations.
Claim 43
Independent Claim
118 words
A system for examining an object internally, the object being capable of converting a burst of electromagnetic energy into a thermal pulse which propagates as an acoustic wave in the object and is internally reflected within the object, the system comprising: an excitation beam scanner for scanning a plurality of bursts of the electromagnetic energy over a surface of the object to generate acoustic waves in the object; a detector for detecting acoustic waves reflected within the object at a plurality of positions on the surface of the object to generate resultant signals; a calculator for calculating a 3-D representation of the object from the resultant signals; and a display for displaying the 3-D representation as an image.
Claim 44
Independent Claim
118 words
A system for examining an object internally, the object being capable of converting a burst of electromagnetic energy into a thermal pulse which propagates as an acoustic wave in the object and is internally reflected within the object, the system comprising: an excitation beam scanner for scanning a plurality of bursts of the electromagnetic energy over a surface of the object to generate acoustic waves in the object; a detector for detecting acoustic waves reflected within the object at a plurality of positions on the surface of the object to generate resultant signals; a calculator for calculating a 3-D representation of the object from the resultant signals; and a display for displaying the 3-D representation as an image.
Claim 45
Dependent Claim
18 words
The system as claimed in claim 40 wherein the bursts of electromagnetic energy are pulses of laser light.
Claim 46
Dependent Claim
59 words
The system as claimed in claim 41 wherein the acoustic waves have a primary wavelength, λ, and wherein the system further comprises an optical element for focusing the pulses of laser light so that each thermal pulse is generated at an area of the object approximately equal to λ 2 so that the acoustic sound waves are spherical waves.
Claim 47
Dependent Claim
39 words
The system as claimed in claim 40 wherein the detector includes a probe beam scanner for scanning the surface with a focused, continuous-wave laser beam operating at a wavelength different than the wavelength of the bursts of electromagnetic energy.
Claim 48
Dependent Claim
51 words
The system as claimed in claim 40 wherein the acoustic waves have a primary wavelength, λ, and wherein the detector includes a probe beam scanner for scanning a probe beam having spot size with a diameter less than λ, over the surface of the object at a plurality of scan positions.
Claim 49
Dependent Claim
20 words
The system as claimed in claim 44 wherein at least one of the scanners includes an electronically driven acoustooptic device.
Claim 50
Dependent Claim
15 words
The system as claimed in claim 45 wherein the acoustooptic device is a Bragg cell.
Claim 51
Dependent Claim
32 words
The system as claimed in claim 44 further comprising a housing wherein the probe beam scanner and the excitation beam scanner are housed in the housing to define an optical needle probe.
Claim 52
Dependent Claim
28 words
The system as claimed in claim 44 further comprising an optical fiber and wherein the probe beam is delivered to the probe beam scanner by the optical fiber.
Claim 53
Dependent Claim
28 words
The system as claimed in claim 44 further comprising an optical fiber and wherein the excitation beam is delivered to the excitation beam scanner by the optical fiber.
Claim 54
Dependent Claim
29 words
The system as claimed in claim 49 wherein the detector includes a photodetector array and wherein a detecting beam is returned to the photodetector array by the optical fiber.
Claim 55
Dependent Claim
49 words
The system as claimed in claim 44 further comprising a single optical fiber and wherein the probe beam is delivered to the probe beam scanner, the excitation beam is delivered to the excitation beam scanner and a detecting beam is delivered to the detector by the single optical fiber.
Claim 56
Dependent Claim
16 words
The system as claimed in claim 40 wherein the detector includes an array of opto-acoustic detectors.
Claim 57
Dependent Claim
65 words
The system as claimed in claim 40 wherein the acoustic waves have a primary wavelength, λ, and wherein the detector includes an ultrasonic microscope transducer for focusing an acoustic spot on the surface of the object, the spot having an area approximately equal to λ 2 and wherein the transducer is utilized to scan in a plane substantially parallel to the surface of the object.
Claim 58
Dependent Claim
26 words
The system as claimed in claim 40 wherein the calculator includes a programmed computer for calculating the 3-D representation based on 3-D synthetic aperture beam-forming equations.
Claim 59
Dependent Claim
149 words
A 3-D acoustic microscope adapted to be used in a system for 3-D acoustic microscopy to examine an object internally, the microscope comprising: an opto-acoustic transducer adapted to be coupled to the object and including an optically reflecting surface and an absorbing layer capable of converting a burst of electromagnetic energy into a thermal pulse so that the thermal pulse propagates as an acoustic wave in the object and is internally reflected within the object; a first acoustooptic scanning device for scanning a plurality of bursts of the electromagnetic energy over a surface of the absorbing layer to generate acoustic waves in the object; a second acoustooptic scanning device for scanning a probe beam at a plurality of positions on the reflecting surface of the opto-acoustic transducer; and a housing for housing the opto-acoustic transducer and the first and second acoustooptic scanning devices to define an optical needle probe.
Claim 60
Dependent Claim
149 words
A 3-D acoustic microscope adapted to be used in a system for 3-D acoustic microscopy to examine an object internally, the microscope comprising: an opto-acoustic transducer adapted to be coupled to the object and including an optically reflecting surface and an absorbing layer capable of converting a burst of electromagnetic energy into a thermal pulse so that the thermal pulse propagates as an acoustic wave in the object and is internally reflected within the object; a first acoustooptic scanning device for scanning a plurality of bursts of the electromagnetic energy over a surface of the absorbing layer to generate acoustic waves in the object; a second acoustooptic scanning device for scanning a probe beam at a plurality of positions on the reflecting surface of the opto-acoustic transducer; and a housing for housing the opto-acoustic transducer and the first and second acoustooptic scanning devices to define an optical needle probe.
Claim 61
Dependent Claim
22 words
The microscope as claimed in claim 55 wherein at least one of the scanning devices is an electronically driven acoustooptic Bragg cell.
Claim 62
Dependent Claim
125 words
A 3-D acoustic microscope adapted to be used in a system for 3-D acoustic microscopy to examine an object internally, the object being capable of converting a burst of electromagnetic energy into a thermal pulse so that the thermal pulse propagates as an acoustic wave in the object and is internally reflected within the object, the microscope comprising: a first acoustooptic scanning device for scanning a plurality of bursts of the electromagnetic energy over a surface of the object to generate acoustic waves in the object; a second acoustooptic scanning device for scanning a probe beam at a plurality of positions on the surface of the object; and a housing for housing the first and second acoustooptic scanning devices to define an optical needle probe.
Claim 63
Dependent Claim
125 words
A 3-D acoustic microscope adapted to be used in a system for 3-D acoustic microscopy to examine an object internally, the object being capable of converting a burst of electromagnetic energy into a thermal pulse so that the thermal pulse propagates as an acoustic wave in the object and is internally reflected within the object, the microscope comprising: a first acoustooptic scanning device for scanning a plurality of bursts of the electromagnetic energy over a surface of the object to generate acoustic waves in the object; a second acoustooptic scanning device for scanning a probe beam at a plurality of positions on the surface of the object; and a housing for housing the first and second acoustooptic scanning devices to define an optical needle probe.
Claim 64
Dependent Claim
22 words
The microscope as claimed in claim 57 wherein at least one of the scanning devices is an electronically driven acoustooptic Bragg cell.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-03-31 | 2000-09-30 | 2001-04-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-03-31 | 2004-09-30 | 2005-04-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-03-31 | 2008-09-30 | 2009-04-01 | $7700.00 | Window Closed / Lapsed |