Patent US5719399A successfully refreshed from Google Patents.
US5719399A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Imaging and characterization of tissue based upon the preservation of polarized light transmitted therethrough
Assignee: Research Foundation of City University of New York
•
Filing: 1995-12-18
•
Granted: 1998-02-17
•
Expires: 2015-12-18
Abstract
Abstract A method and apparatus for imaging and/or characterizing a tissue based upon the extent to which initially polarized light maintains its polarization after propagating through the tissue. In a preferred embodiment, the present invention relates to a method for identifying a tissue in question, the method comprising the steps of: (a) illuminating the tissue with a pulse of light, the pulse of light being polarized and having an initial state of polarization, whereby light consisting of a ballistic component, a snake-like component and a diffuse component emerges from the illuminated tissue; (b) passing the emergent light from the illuminated tissue through one of a polarizer oriented parallel to the initial state of polarization of the pulse of light and an analyzer oriented perpendicular to the initial state of polarization of the pulse of light; (c) detecting the light passed through one of the polarizer and the analyzer; and (d) comparing the detected light to appropriate standards so as to identify the type of tissue tested, i.e., breast and brain for optical mammography and tomography.
Inventors
- 👤 Robert R. Alfano
- 👤 Stavros G. Demos
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 19:33
CPC Classifications
A; A61; A61B; A61B5/00; A61B5/0059; A61B5/0082; A61B5/0091; A61B1/00; A61B1/04; A61B1/042; A61B5/0084; A61B5/0086; A61B5/43; A61B5/4306; A61B5/4312; G; G01; G01N; G01N21/00; G01N21/17; G01N21/47; G01N21/4795; G01N21/49
Claims Analysis
Total Claims: 70
Claim 1
Independent Claim
137 words
A method for imaging an object located in or behind a human breast tissue sample, said method comprising the steps of: (a) illuminating the object through the human breast tissue sample with a pulse of light, the pulse of light having a wavelength selected from the group consisting of 532 nm and 1064 nm, being polarized and having an initial state of polarization, whereby light consisting of a ballistic component, a snake-like component and a diffuse component emerges from the illuminated human breast tissue sample; (b) passing the emergent light from the illuminated human breast tissue sample through a polarizing means oriented parallel to the initial state of polarization of said pulse of light to preferentially select said ballistic component and said snake-like component; and (c) forming an image of the light passed through said polarizing means.
Claim 2
Independent Claim
137 words
A method for imaging an object located in or behind a human breast tissue sample, said method comprising the steps of: (a) illuminating the object through the human breast tissue sample with a pulse of light, the pulse of light having a wavelength selected from the group consisting of 532 nm and 1064 nm, being polarized and having an initial state of polarization, whereby light consisting of a ballistic component, a snake-like component and a diffuse component emerges from the illuminated human breast tissue sample; (b) passing the emergent light from the illuminated human breast tissue sample through a polarizing means oriented parallel to the initial state of polarization of said pulse of light to preferentially select said ballistic component and said snake-like component; and (c) forming an image of the light passed through said polarizing means.
Claim 3
Dependent Claim
20 words
The method as claimed in claim 1 wherein the initial state of polarization of the pulse of light is linear.
Claim 4
Dependent Claim
20 words
The method as claimed in claim 1 wherein the initial state of polarization of the pulse of light is elliptical.
Claim 5
Independent Claim
113 words
A method for imaging an object located in or behind a turbid medium, said method comprising the steps of: (a) providing a beam of light; (b) polarizing the beam of light, whereby the beam of light has an initial state of polarization; (c) illuminating the object through the turbid medium with the polarized beam of light, whereby light consisting of a ballistic component, a snake-like component and a diffuse component emerges from the illuminated turbid medium; (d) detecting the degree of polarization of the emergent light to determine the extent to which the emergent light includes the ballistic and snake-like components; and (e) forming an image of the object using the detected light.
Claim 6
Independent Claim
113 words
A method for imaging an object located in or behind a turbid medium, said method comprising the steps of: (a) providing a beam of light; (b) polarizing the beam of light, whereby the beam of light has an initial state of polarization; (c) illuminating the object through the turbid medium with the polarized beam of light, whereby light consisting of a ballistic component, a snake-like component and a diffuse component emerges from the illuminated turbid medium; (d) detecting the degree of polarization of the emergent light to determine the extent to which the emergent light includes the ballistic and snake-like components; and (e) forming an image of the object using the detected light.
Claim 7
Dependent Claim
19 words
The method as claimed in claim 4 wherein said detecting step comprises passing the emergent light through polarizing means.
Claim 8
Dependent Claim
19 words
The method as claimed in claim 5 wherein said polarizing means includes a retardation plate and a linear polarizer.
Claim 9
Dependent Claim
32 words
The method as claimed in claim 4 wherein said detecting step comprises detecting light point by point or over an area using photomultiplier or photocathode or CCD camera or other equivalent photodetector.
Claim 10
Dependent Claim
17 words
The method as claimed in claim 4 wherein said beam of light is a pulse of light.
Claim 11
Dependent Claim
21 words
The method as claimed in claim 4 wherein said beam of light is provided by means of a continuous light source.
Claim 12
Independent Claim
136 words
A method for imaging an object located in or behind a turbid medium, said method comprising the steps of: (a) illuminating the object through the turbid medium with a pulse of light, the pulse of light being passed through a polarizer and having an initial state of polarization, whereby light consisting of a ballistic component, a snake-like component and a diffuse component emerges from the illuminated turbid medium; (b) passing the emergent light from the illuminated turbid medium through an analyzer appropriately oriented relative to said polarizer so as to alternately transmit light of two polarization states; (c) collecting the emerged light in the two polarization states to measure the emerged polarized light which belongs to the ballistic and snake-like components; and (d) forming an image of the degree of polarization D of the emerged light.
Claim 13
Independent Claim
136 words
A method for imaging an object located in or behind a turbid medium, said method comprising the steps of: (a) illuminating the object through the turbid medium with a pulse of light, the pulse of light being passed through a polarizer and having an initial state of polarization, whereby light consisting of a ballistic component, a snake-like component and a diffuse component emerges from the illuminated turbid medium; (b) passing the emergent light from the illuminated turbid medium through an analyzer appropriately oriented relative to said polarizer so as to alternately transmit light of two polarization states; (c) collecting the emerged light in the two polarization states to measure the emerged polarized light which belongs to the ballistic and snake-like components; and (d) forming an image of the degree of polarization D of the emerged light.
Claim 14
Dependent Claim
65 words
The method as claimed in claim 10 wherein the degree of polarization D is measured by a function containing the two polarization components I a and I b of the emergent light, such as d(t)=I a (t)-I b (t), p(t)=I a (t)/I b (t), D(t)= I a (t)-I b (t)!/ I a (t)+I b (t)! or D'(t)= I b (t)!/ I a (t)-I b (t)!.
Claim 15
Dependent Claim
19 words
The method as claimed in claim 11 wherein the degree of polarization D is the peak value of D(t).
Claim 16
Dependent Claim
22 words
The method as claimed in claim 11 wherein the degree of polarization D is the averaged integral in time value of D(t).
Claim 17
Dependent Claim
30 words
The method as claimed in claim 11 wherein the degree of polarization is obtained using the averaged integral in time value of the two polarization components of the emerged light.
Claim 18
Dependent Claim
17 words
The method as claimed in claim 11 wherein the emergent light is time-gated using appropriate time-gating apparatus.
Claim 19
Dependent Claim
24 words
The method as claimed in claim 11 wherein the emergent light is passed through a spatial gate, such as a 4F Fourier spatial gate.
Claim 20
Dependent Claim
39 words
The method as claimed in claim 11 wherein subtraction of the two polarization components of the emergent light is equivalent to a time gate of less than 100 ps in time duration following the arrival of the ballistic component.
Claim 21
Dependent Claim
64 words
The method as claimed in claim 11 wherein the image is recorded in two or three dimensional map of D(R,t) or D(R) wherein R is the spatial coordinate in the sample and t is time, describing the dependence of the degree of polarization of the emergent light from different parts of the tissue D(R) and the time profile of the degree of polarization D(t).
Claim 22
Dependent Claim
26 words
The method as claimed in claim 11 wherein the pulse of light has a wavelength selected from the group consisting of 532 nm and 1064 nm.
Claim 23
Independent Claim
254 words
A method for imaging a tissue and for identifying the tissue, said method comprising the steps of: (a) illuminating the tissue with a first pulse of light passing through a polarizer, the first pulse of light having an initial state of polarization, whereby light from the first pulse consisting of a ballistic component, a snake-like component and a diffuse component emerges from the illuminated tissue; (b) passing the light from the first pulse emergent from the illuminated tissue through an analyzer appropriately oriented relative to said polarizer so as to alternately transmit light of two polarization states; (c) forming an image of the degree of polarization of the emergent light from the first pulse; (d) illuminating the tissue with a second pulse of light having a different wavelength than the first pulse, the second pulse of light passing through a polarizer and having an initial state of polarization, whereby light from the second pulse consisting of a ballistic component, a snake-like component and a diffuse component emerges from the illuminated tissue; (e) passing the light from the second pulse emergent from the illuminated tissue through an analyzer appropriately oriented relative to said polarizer so as to alternately transmit light of two polarization states; (f) forming an image of the degree of polarization of the emergent light from the second pulse; (g) repeating steps (d) through (f) if required; and (h) forming an image of the tissue, said image containing information regarding the type of tissue using the images formed in steps (c) and (f).
Claim 24
Independent Claim
254 words
A method for imaging a tissue and for identifying the tissue, said method comprising the steps of: (a) illuminating the tissue with a first pulse of light passing through a polarizer, the first pulse of light having an initial state of polarization, whereby light from the first pulse consisting of a ballistic component, a snake-like component and a diffuse component emerges from the illuminated tissue; (b) passing the light from the first pulse emergent from the illuminated tissue through an analyzer appropriately oriented relative to said polarizer so as to alternately transmit light of two polarization states; (c) forming an image of the degree of polarization of the emergent light from the first pulse; (d) illuminating the tissue with a second pulse of light having a different wavelength than the first pulse, the second pulse of light passing through a polarizer and having an initial state of polarization, whereby light from the second pulse consisting of a ballistic component, a snake-like component and a diffuse component emerges from the illuminated tissue; (e) passing the light from the second pulse emergent from the illuminated tissue through an analyzer appropriately oriented relative to said polarizer so as to alternately transmit light of two polarization states; (f) forming an image of the degree of polarization of the emergent light from the second pulse; (g) repeating steps (d) through (f) if required; and (h) forming an image of the tissue, said image containing information regarding the type of tissue using the images formed in steps (c) and (f).
Claim 25
Dependent Claim
17 words
The method as claimed in claim 20 wherein the tissue sample is a human brain tissue sample.
Claim 26
Dependent Claim
40 words
The method as claimed in claim 20 wherein the pulse of light is a laser pulse of light generated by a laser selected from the group consisting of Ti:Sapphire, Cr 4+ :Forsterite, Cr 4+ :YAG, Nd:YAG and semiconductor diode lasers.
Claim 27
Dependent Claim
25 words
The method as claimed in claim 20 wherein the pulse of light is replaced with a continuous monochromatic light source from a lamp or laser.
Claim 28
Dependent Claim
20 words
The method as claimed in claim 20 wherein the pulse of light is replaced with a continuous non-monochromatic light source.
Claim 29
Dependent Claim
29 words
The method as claimed in claim 23 wherein the different wavelengths of the first and second pulses are measured from the central wavelength of the band of frequencies utilized.
Claim 30
Dependent Claim
28 words
The method as claimed in claim 24 wherein the different wavelengths of the first and second pulses are measured from the bandwidth of the band of frequencies utilized.
Claim 31
Dependent Claim
37 words
The method as claimed in claim 20 wherein the polarization of the illuminating light pulse is linear and the two states of polarization of the emergent light is parallel and perpendicular to the incident light pulse polarization.
Claim 32
Dependent Claim
28 words
The method as claimed in claim 20 wherein the polarization is circular and the two states of polarization of the emergent light is right-hand and left-hand circularly polarized.
Claim 33
Dependent Claim
23 words
The method as claimed in claim 20 wherein the polarizer comprises appropriate optical elements to define the polarization state of the illuminating light.
Claim 34
Dependent Claim
17 words
The method as claimed in claim 28 wherein the polarizer comprises a retardation plate and linear polarizer.
Claim 35
Dependent Claim
25 words
The method as claimed in claim 20 wherein the imaging is performed point by point or over area using photomultiplier or photodiode or CCD camera.
Claim 36
Dependent Claim
65 words
The method as claimed in claim 20 wherein the degree of polarization D is measured by a function containing the two polarization components I a and I b of the emergent light, such as d(t)=I a (t)-I b (t), p(t)=I a (t)/I b (t), D(t)= I a (t)-I b (t)!/ I a (t)+I b (t)! or D'(t)= I b (t)!/ I a (t)-I b (t)!.
Claim 37
Dependent Claim
19 words
The method as claimed in claim 32 wherein the degree of polarization D is the peak value of D(t).
Claim 38
Dependent Claim
22 words
The method as claimed in claim 32 wherein the degree of polarization D is the averaged integral in time value of D(t).
Claim 39
Dependent Claim
30 words
The method as claimed in claim 32 wherein the degree of polarization is obtained using the averaged integral in time value of the two polarization components of the emerged light.
Claim 40
Dependent Claim
17 words
The method as claimed in claim 20 wherein the emergent light is time-gated using appropriate time-gating apparatus.
Claim 41
Dependent Claim
24 words
The method as claimed in claim 20 wherein the emergent light is passed through a spatial gate, such as a 4F Fourier spatial gate.
Claim 42
Dependent Claim
35 words
The method as claimed in claim 20 wherein the image containing the information regarding the type of tissue is obtained utilizing the different degree of polarization that different types of tissues exhibit at different wavelengths.
Claim 43
Dependent Claim
91 words
The method as claimed in claim 20 wherein the image containing the information regarding the type of tissue is recorded in a two or three dimensional map of D(R,t,λ) or D(R) wherein R is the spatial coordinate in the sample, t is time and λ is wavelength, describing the dependence of the degree of polarization of the emergent light from different parts of the tissue D(R), the time profile of the degree of polarization D(t) and the dependence of the degree of polarization in the wavelength of the illuminating light D(λ).
Claim 44
Dependent Claim
64 words
The method as claimed in claim 20 wherein the image containing the information regarding the type of tissue is recorded in a two or three dimensional map of D(R,λ) describing the dependence of the degree of polarization of the emergent light from different parts of the tissue D(R) and the dependence of the degree of polarization in the wavelength of the illuminating light D(λ).
Claim 45
Dependent Claim
38 words
The method as claimed in claim 20 wherein the selection of different wavelengths is based on the wavelength of absorption peaks and minima of the tissue under investigation arising from H 2 O and/or fat to highlight tumors.
Claim 46
Independent Claim
260 words
A method for imaging an object located in or behind a turbid medium, said method comprising the steps of: (a) illuminating the object through the turbid medium with a first pulse of light, the first pulse of light being polarized and having an initial state of polarization, whereby light from the first pulse consisting of a ballistic component, a snake-like component and a diffuse component emerges from the illuminated turbid medium; (b) passing the light from the first pulse emergent from the illuminated turbid medium through one of a polarizer oriented parallel to the initial state of polarization of said first pulse of light and an analyzer oriented perpendicular to the initial state of polarization of said first pulse of light; (c) detecting the light from the first pulse passed through one of said polarizer and said analyzer; (d) illuminating the object through the turbid medium with a second pulse of light, the, second pulse of light being polarized in an initial state parallel to that of said first pulse of light, whereby light from the second pulse consisting of a ballistic component, a snake-like component and a diffuse component emerges from the illuminated turbid medium; (e) passing the light from the second pulse emergent from the illuminated turbid medium through the other of said polarizer and said analyzer; (f) detecting the light from the second pulse passed through the other of said polarizer and said analyzer; and (g) forming an image of the object in or behind the turbid medium using the light detected in steps (c) and (f).
Claim 47
Independent Claim
260 words
A method for imaging an object located in or behind a turbid medium, said method comprising the steps of: (a) illuminating the object through the turbid medium with a first pulse of light, the first pulse of light being polarized and having an initial state of polarization, whereby light from the first pulse consisting of a ballistic component, a snake-like component and a diffuse component emerges from the illuminated turbid medium; (b) passing the light from the first pulse emergent from the illuminated turbid medium through one of a polarizer oriented parallel to the initial state of polarization of said first pulse of light and an analyzer oriented perpendicular to the initial state of polarization of said first pulse of light; (c) detecting the light from the first pulse passed through one of said polarizer and said analyzer; (d) illuminating the object through the turbid medium with a second pulse of light, the, second pulse of light being polarized in an initial state parallel to that of said first pulse of light, whereby light from the second pulse consisting of a ballistic component, a snake-like component and a diffuse component emerges from the illuminated turbid medium; (e) passing the light from the second pulse emergent from the illuminated turbid medium through the other of said polarizer and said analyzer; (f) detecting the light from the second pulse passed through the other of said polarizer and said analyzer; and (g) forming an image of the object in or behind the turbid medium using the light detected in steps (c) and (f).
Claim 48
Dependent Claim
15 words
The method as claimed in claim 42 wherein the turbid medium is a tissue sample.
Claim 49
Dependent Claim
16 words
The method as claimed in claim 43 wherein the tissue sample is a human tissue sample.
Claim 50
Dependent Claim
17 words
The method as claimed in claim 44 wherein the tissue sample is a human breast tissue sample.
Claim 51
Dependent Claim
18 words
The method as claimed in claim 42 wherein the pulse of light is a pulse of laser light.
Claim 52
Dependent Claim
24 words
The method as claimed in claim 42 wherein the pulse of light has a wavelength in the spectral region between 400 and 1600 nm.
Claim 53
Dependent Claim
26 words
The method as claimed in claim 47 wherein the pulse of light has a wavelength selected from the group consisting of 532 nm and 1064 nm.
Claim 54
Independent Claim
127 words
A method for identifying a tissue, said method comprising the steps of: (a) illuminating the tissue with a pulse of light, the pulse of light being polarized and having an initial state of polarization, whereby light consisting of a ballistic component, a snake-like component and a diffuse component emerges from the illuminated tissue; (b) passing the emergent light from the illuminated tissue through one of a polarizer oriented consistent with the initial state of polarization of said pulse of light and an analyzer oriented opposite to the initial state of polarization of said pulse of light; (c) detecting the light passed through one of said polarizer and said analyzer; and (d) comparing the detected light to appropriate standards so as to identify the type of tissue tested.
Claim 55
Independent Claim
127 words
A method for identifying a tissue, said method comprising the steps of: (a) illuminating the tissue with a pulse of light, the pulse of light being polarized and having an initial state of polarization, whereby light consisting of a ballistic component, a snake-like component and a diffuse component emerges from the illuminated tissue; (b) passing the emergent light from the illuminated tissue through one of a polarizer oriented consistent with the initial state of polarization of said pulse of light and an analyzer oriented opposite to the initial state of polarization of said pulse of light; (c) detecting the light passed through one of said polarizer and said analyzer; and (d) comparing the detected light to appropriate standards so as to identify the type of tissue tested.
Claim 56
Dependent Claim
32 words
The method as claimed in claim 49 wherein said passing step comprising passing the emergent light through a polarizer oriented consistent with the initial state of polarization of said pulse of light.
Claim 57
Dependent Claim
32 words
The method as claimed in claim 49 wherein said passing step comprising passing the emergent light through an analyzer oriented opposite to the initial state of polarization of said pulse of light.
Claim 58
Dependent Claim
14 words
The method as claimed in claim 49 wherein the tissue is a human tissue.
Claim 59
Dependent Claim
15 words
The method as claimed in claim 52 wherein the tissue is a human breast tissue.
Claim 60
Dependent Claim
18 words
The method as claimed in claim 49 wherein the pulse of light is a pulse of laser light.
Claim 61
Dependent Claim
24 words
The method as claimed in claim 49 wherein the pulse of light has a wavelength in the spectral region between 400 and 1600 nm.
Claim 62
Dependent Claim
26 words
The method as claimed in claim 55 wherein the pulse of light has a wavelength selected from the group consisting of 532 nm and 1064 nm.
Claim 63
Independent Claim
135 words
An apparatus for imaging an object in a turbid medium, the apparatus comprising: (a) means for illuminating an object in a turbid medium from a first side thereof with light, said light being polarized and having an initial state of polarization, whereby light consisting of a ballistic component, a snake-like component and a diffuse component emerges from the turbid medium; (b) polarization means for alternately passing the parallel and perpendicular components of the light emergent from the turbid medium; (c) means for detecting the parallel and perpendicular components of the emergent light; (d) means for calculating one of a ratio and a difference of the parallel and perpendicular components of the emergent light; (e) means for forming an image of the object in the turbid medium using said one of said ratio and said difference.
Claim 64
Independent Claim
135 words
An apparatus for imaging an object in a turbid medium, the apparatus comprising: (a) means for illuminating an object in a turbid medium from a first side thereof with light, said light being polarized and having an initial state of polarization, whereby light consisting of a ballistic component, a snake-like component and a diffuse component emerges from the turbid medium; (b) polarization means for alternately passing the parallel and perpendicular components of the light emergent from the turbid medium; (c) means for detecting the parallel and perpendicular components of the emergent light; (d) means for calculating one of a ratio and a difference of the parallel and perpendicular components of the emergent light; (e) means for forming an image of the object in the turbid medium using said one of said ratio and said difference.
Claim 65
Dependent Claim
31 words
The apparatus as claimed in claim 57 further comprising means, located between said detecting means and the turbid medium for time and/or space gating the light emergent from the turbid medium.
Claim 66
Independent Claim
92 words
An apparatus for imaging an object in a turbid medium, the apparatus comprising: (a) a light source for emitting a beam of light towards the turbid medium; (b) means for polarizing the beam of light prior to illuminating the turbid medium; (c) analyzing means for selectively passing the light emergent from the turbid medium based upon its polarization; (d) means for detecting the analyzed light; and (e) means for generating a one or two or three dimensional map of the degree of polarization (D or d or p) of the emerged light.
Claim 67
Independent Claim
92 words
An apparatus for imaging an object in a turbid medium, the apparatus comprising: (a) a light source for emitting a beam of light towards the turbid medium; (b) means for polarizing the beam of light prior to illuminating the turbid medium; (c) analyzing means for selectively passing the light emergent from the turbid medium based upon its polarization; (d) means for detecting the analyzed light; and (e) means for generating a one or two or three dimensional map of the degree of polarization (D or d or p) of the emerged light.
Claim 68
Dependent Claim
23 words
The apparatus as claimed in claim 59 further comprising a time and/or space gate disposed between the turbid medium and the analyzing means.
Claim 69
Dependent Claim
23 words
The apparatus as claimed in claim 59 further comprising a time and/or space gate disposed between the analyzing means and the detecting means.
Claim 70
Dependent Claim
27 words
The apparatus as claimed in claim 59 further comprising a movable mounting table upon which the light source, polarizing means, analyzing means and detecting means are mounted.
References Cited (Backward Citations)
US4945239A
Cited
US5371368A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-02-16 | 2001-08-18 | 2002-02-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-02-16 | 2005-08-18 | 2006-02-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-02-16 | 2009-08-18 | 2010-02-17 | $7700.00 | Window Closed / Lapsed |