LOW COHERENCE INTERFEROMETRY UTILIZING PHASE
First Claim
1. A method for diagnosing a human condition from a characteristic of plaque in a subject, the method comprising:
- directing broadband light by means of a sensing light path at an area of interest in the subject, at a target depth defined by said sensing light path and a reference light path;
receiving said broadband light reflected from the area of interest in the subject by means of said sensing light path;
directing said broadband light by means of said reference light path at a reflecting device;
receiving said broadband light reflected from said reflecting device by means of said reference light path;
modulating at about a distance of a center wavelength of said broadband light an effective light path length of at least one of said reference light path and said sensing light path with respect to said target depth;
detecting said broadband light resulting from said broadband light reflected from said target depth in the biological sample and said broadband light reflected from said reflecting device, to generate a signal indicative of an interference of said broadband light reflected from said target depth at the area of interest in the subject and said broadband light reflected from said reflecting device, wherein said signal is a product of a cosine function;
determining a phase component that is an argument of the cosine function;
determining a change in the phase component angle of said signal resulting from a change of said effective light path length that is itself induced by a change of a property of the area of interest in the subject;
determining a variation in an index of refraction from said change in the phase component of said signal;
determining the characteristic of the plaque in the subject from said variation in said index of refraction; and
diagnosing a human condition from the characteristic.
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Accused Products
Abstract
A method for diagnosing a human condition from a characteristic of a plaque or tissue in a subject is presented. The method includes directing broadband light by means of a sensing light path at an area of interest in the subject, at a target depth defined by the sensing light path and a reference light path. The continues with receiving the broadband light reflected from the area of interest in the subject by means of the sensing light path. The method further includes directing the broadband light by means of the reference light path at a reflecting device, and receiving the broadband light reflected from the reflecting device by means of the reference light path. The method also includes modulating at about a distance of a center wavelength of the broadband light an effective light path length of at least one of the reference light path and the sensing light path with respect to the target depth. The method still further includes detecting the broadband light resulting from the broadband light reflected from the target depth in the biological sample and the broadband light reflected from the reflecting device, to generate a signal indicative of an interference of the broadband light reflected from the target depth at the area of interest in the subject and the broadband light reflected from the reflecting device, wherein the signal is a product of a cosine function. The method continues with determining a phase component that is an argument of the cosine function, determining a change in the phase component angle of the signal resulting from a change of the effective light path length that is itself induced by a change of a property of the area of interest in the subject, determining a variation in an index of refraction from the change in the phase component of the signal, and determining the characteristic of the plaque or tissue in the subject from the variation in the index of refraction. Finally the method includes diagnosing a human condition from the characteristic.
120 Citations
46 Claims
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1. A method for diagnosing a human condition from a characteristic of plaque in a subject, the method comprising:
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directing broadband light by means of a sensing light path at an area of interest in the subject, at a target depth defined by said sensing light path and a reference light path;
receiving said broadband light reflected from the area of interest in the subject by means of said sensing light path;
directing said broadband light by means of said reference light path at a reflecting device;
receiving said broadband light reflected from said reflecting device by means of said reference light path;
modulating at about a distance of a center wavelength of said broadband light an effective light path length of at least one of said reference light path and said sensing light path with respect to said target depth;
detecting said broadband light resulting from said broadband light reflected from said target depth in the biological sample and said broadband light reflected from said reflecting device, to generate a signal indicative of an interference of said broadband light reflected from said target depth at the area of interest in the subject and said broadband light reflected from said reflecting device, wherein said signal is a product of a cosine function;
determining a phase component that is an argument of the cosine function;
determining a change in the phase component angle of said signal resulting from a change of said effective light path length that is itself induced by a change of a property of the area of interest in the subject;
determining a variation in an index of refraction from said change in the phase component of said signal;
determining the characteristic of the plaque in the subject from said variation in said index of refraction; and
diagnosing a human condition from the characteristic. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 31)
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13. A system for determining a characteristic of a plaque in a subject, the system comprising:
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a broadband light source for providing a broadband light;
a sensing light path receptive to said broadband light from said broadband light source, said sensing light path configured to direct said broadband light at an area of interest in the subject and to receive said broadband light reflected from the biological sample;
a reflecting device;
a reference light path receptive to said broadband light from said broadband light source, said reference light path configured to direct said broadband light at said reflecting device and to receive said broadband light reflected from said reflecting device, said reference light path and said sensing light path cooperating to define a target depth;
a modulator associated with at least one of said reference light path and said sensing light path, said modulator for modulating at about a distance of a center wavelength of said broadband light an effective light path length of said at least one of said reference light path and said sensing light path;
a detector receptive to said broadband light resulting from said broadband light reflected from the area of interest in the subject and said broadband light reflected from said reflecting device, said detector generating a signal indicative of an interference of said broadband light reflected from said target depth at the area of interest in the subject and said broadband light reflected from said reflecting device, wherein said signal is a product of a cosine function; and
processing means configured to determine a phase component that is an argument of the cosine function, said processing means further configured to determine a change in the phase component of said signal resulting from a change of said effective light path length that is itself induced by a change of a property of the area of interest in the subject, a variation in an index of refraction from said change in the phase component of said signal, and the characteristic of the plaque in the subject from said variation in said index of refraction. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20, 21, 22, 23)
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24. A method for diagnosing a human condition from a characteristic of a tissue in a subject, the method comprising:
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directing broadband light by means of a sensing light path at an area of interest in the subject, at a target depth defined by said sensing light path and a reference light path;
receiving said broadband light reflected from the area of interest in the subject by means of said sensing light path;
directing said broadband light by means of said reference light path at a reflecting device;
receiving said broadband light reflected from said reflecting device by means of said reference light path;
modulating at about a distance of a center wavelength of said broadband light an effective light path length of at least one of said reference light path and said sensing light path with respect to said target depth;
detecting said broadband light resulting from said broadband light reflected from said target depth in the biological sample and said broadband light reflected from said reflecting device, to generate a signal indicative of an interference of said broadband light reflected from said target depth at the area of interest in the subject and said broadband light reflected from said reflecting device, wherein said signal is a product of a cosine function;
determining a phase component that is an argument of the cosine function;
determining a change in the phase component angle of said signal resulting from a change of said effective light path length that is itself induced by a change of a property of the area of interest in the subject;
determining a variation in an index of refraction from said change in the phase component of said signal;
determining the characteristic of the tissue in the subject from said variation in said index of refraction; and
diagnosing a human condition from the characteristic. - View Dependent Claims (25, 26, 27, 28, 29, 30, 32, 33, 34, 35)
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36. A system for determining a characteristic of a tissue in a subject, the system comprising:
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a broadband light source for providing a broadband light;
a sensing light path receptive to said broadband light from said broadband light source, said sensing light path configured to direct said broadband light at an area of interest in the subject and to receive said broadband light reflected from the biological sample;
a reflecting device;
a reference light path receptive to said broadband light from said broadband light source, said reference light path configured to direct said broadband light at said reflecting device and to receive said broadband light reflected from said reflecting device, said reference light path and said sensing light path cooperating to define a target depth;
a modulator associated with at least one of said reference light path and said sensing light path, said modulator for modulating at about a distance of a center wavelength of said broadband light an effective light path length of said at least one of said reference light path and said sensing light path;
a detector receptive to said broadband light resulting from said broadband light reflected from the area of interest in the subject and said broadband light reflected from said reflecting device, said detector generating a signal indicative of an interference of said broadband light reflected from said target depth at the area of interest in the subject and said broadband light reflected from said reflecting device, wherein said signal is a product of a cosine function; and
processing means configured to determine a phase component that is an argument of the cosine function, said processing means further configured to determine a change in the phase component of said signal resulting from a change of said effective light path length that is itself induced by a change of a property of the area of interest in the subject, a variation in an index of refraction from said change in the phase component of said signal, and the characteristic of the tissue in the subject from said variation in said index of refraction. - View Dependent Claims (37, 38, 39, 40, 41, 42, 43, 44, 45, 46)
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Specification