Extended focal region measuring apparatus and method
First Claim
1. A method of measuring an apparent depth of a section of an animal body, the section being defined by first and second interfaces, comprising the steps:
- a) focusing a monochromatic incident beam of light to a plurality or continuum of measurement locations along a measurement line passing through the section, the measurement line being generated by an optical element adapted to provide an extended focal region for monochromatic light, such that incident light is focused to all measurement locations along the measurement line concurrently;
b) detecting light reflected from at least one of the plurality of measurement locations when a respective interface is coincident therewith;
c) generating at least a first and a second signal representative of the detected light reflected from the first and second interfaces respectively; and
d) deriving from the first and second signals the apparent positions of the first and second interfaces.
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Accused Products
Abstract
A method and apparatus for measuring an apparent depth of a section of an animal body are disclosed. Light is focused concurrently to an extended focal region comprising a plurality or continuum of measurement locations. Light reflected by a refractive index interface coincident with one of the plurality of measurement locations is detected. Detected light signals are generated from light reflected from first and second interfaces respectively defining the section under investigation, so that the apparent positions of the interfaces may be derived. A confocal arrangement and an axicon element may be employed. Preferably, the section is the aqueous humor of an eye. From changes in its refractive index corresponding changes in glucose concentration in the aqueous humor and, in turn, in the bloodstream of a patient may be derived, offering a non-invasive monitoring means for diabetic patients. Other compounds and structures of the body may alternatively be investigated.
69 Citations
14 Claims
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1. A method of measuring an apparent depth of a section of an animal body, the section being defined by first and second interfaces, comprising the steps:
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a) focusing a monochromatic incident beam of light to a plurality or continuum of measurement locations along a measurement line passing through the section, the measurement line being generated by an optical element adapted to provide an extended focal region for monochromatic light, such that incident light is focused to all measurement locations along the measurement line concurrently; b) detecting light reflected from at least one of the plurality of measurement locations when a respective interface is coincident therewith; c) generating at least a first and a second signal representative of the detected light reflected from the first and second interfaces respectively; and d) deriving from the first and second signals the apparent positions of the first and second interfaces. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. An apparatus for measuring an apparent depth of a section of an animal body, the section being defined by first and second interfaces, comprising:
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a) an optical focusing assembly, comprising an optical element adapted to provide an expanded focal region for monochromatic light, the optical focusing assembly being adapted to focus a monochromatic incident beam of light to a plurality or continuum of measurement locations along a measurement line passing through the section, such that incident light is focused to all measurement locations along the measurement line concurrently; b) a detector assembly, adapted to detect light reflected from at least one of the plurality of measurement locations when a respective interface is coincident therewith and to generate a signal representative of that detected light; and c) a processor in communication with the detector assembly and adapted to receive from the detector assembly first and second signals corresponding to detected light reflected from the first and second interfaces respectively and to derive therefrom apparent positions of the first and second interfaces. - View Dependent Claims (11, 12, 13, 14)
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Specification