EP0072185A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Reflected light measuring apparatus
Assignee: Imperial Chemical Industries Ltd
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Filing: 1982-08-03
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Granted: —
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Expires: 2002-08-03
Abstract
Abstract The invention concerns a novel apparatus for measuring the reflectance of a coloured area of skin in response to green light as a means for assessing the degree of erythema or pigmentation of the area of skin. The apparatus (shown in partial cross-section in Fig. 2) has a mutually screened, green light emitting diode (10) and photosensitive electrical component (8) (typically a cadmium sulphide photoresistor or a silicon photodiode), arranged in a holder (1) and connected to conventional electronic circuitry, so that the amount of light reflected by the area of skin and impinging on the component (8) may be measured and then displayed on a voltmeter allowing a quantitative assessment of erythema or pigmentation. The apparatus has both medical, veterinary and cosmetic applications, for example in assessing the response to treatment of inflammation of the skin, or a safe level of exposure to UV light.
Inventors
- 👤 Philip Anthony Arundel
- 👤 George Brian Horsfall
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-23 10:39
CPC Classifications
A; A61; A61B; A61B5/00; A61B5/41; A61B5/414; A61B5/415; A61B5/145; A61B5/1455; G; G01; G01N; G01N21/00; G01N21/17; G01N21/47; G01N21/4738; G01N21/474
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
124 words
An apparatus for measuring the light reflected by a coloured area of skin of a warm-blooded animal, said apparatus comprising a green light emitting diode (10) provided in use with an essentially constant electric current, and a light detector having a photosensitive electric component (8) connected to a conventional circuit for detecting and measuring light induced electrical changes in the photosensitive component (8), said diode (10) and photosensitive component (8) being situated and mutually screened within a holder which is generally closed apart from an aperture, so that, in use, substantially all the light received by said photosensitive component (8) is that which has been reflected from the area of skin under investigation, via said aperture and having been emitted by said diode (10).
Claim 2
Independent Claim
124 words
An apparatus for measuring the light reflected by a coloured area of skin of a warm-blooded animal, said apparatus comprising a green light emitting diode (10) provided in use with an essentially constant electric current, and a light detector having a photosensitive electric component (8) connected to a conventional circuit for detecting and measuring light induced electrical changes in the photosensitive component (8), said diode (10) and photosensitive component (8) being situated and mutually screened within a holder which is generally closed apart from an aperture, so that, in use, substantially all the light received by said photosensitive component (8) is that which has been reflected from the area of skin under investigation, via said aperture and having been emitted by said diode (10).
Claim 3
Dependent Claim
30 words
An apparatus as claimed in claim 1 having a light guide (6) situated between the aperture of the apparatus and the photosensitive component (8) and/or the light emitting diode (10).
Claim 4
Dependent Claim
21 words
An apparatus as claimed in claim 1 or 2 wherein the photosensitive electric component (8) is a photoresistor or photovoltaic device.
Claim 5
Dependent Claim
33 words
An apparatus as claimed in claim 1, 2 or 3 wherein the light emitting diode (10) and photosensitive component (8) are situated co-axially within the holder and centrally disposed relative to the aperture.
Claim 6
Independent Claim
62 words
An apparatus as claimed in any of claims 1-4 wherein the light detector comprises a photoresistor, connected into one arm of a conventional bridge circuit, and a voltmeter, said circuit provided in use with an essentially constant input voltage, whereby changes in light intensity reaching said photoresistor are measurable as changes in voltage output across the bridge by means of said voltmeter.
Claim 7
Dependent Claim
15 words
An apparatus as claimed in claim 5 wherein the photoresistor is a cadmium sulphide photoresistor.
Claim 8
Independent Claim
62 words
An apparatus as claimed in any of claims 1-4 wherein the light detector comprises a photovoltaic device connected via an operational amplifier to a voltmeter whereby, in use, changes in light intensity reaching said device cause a change in the short circuit current output therefrom, which output is fed to said amplifier whose voltage output is measured by means of said voltmeter.
Claim 9
Dependent Claim
15 words
An apparatus as claimed in claim 7 wherein the photovoltaic device is a silicon photodiode.
Claim 10
Independent Claim
18 words
An apparatus as claimed in any one preceding claim wherein the light emitting diode is a GaAsP device.
Claim 11
Independent Claim
173 words
A method of assessing the degree of erythema or pigmentation of an area of skin of a warm-blooded animal which includes the steps of:-(i) applying to said area of skin an apparatus comprising a green light emitting diode (10) provided with an essentially constant electric current, and a light detector having a photosensitive electric component (8) connected to a conventional circuit for detecting and measuring light induced electrical changes in the photosensitive component (8), said diode (10) and photosensitive component (8) being situated and mutually screened within a holder which is generally closed apart from an aperture so that substantially all the light received by said photosensitive component (8) is that reflected from said area of skin via said aperture and having been emitted by said diode (10); (ii) measuring the electrical changes produced in the photosensitive electric component (8) resulting from the light reflected by said area of skin; and (iii) comparing said electrical changes with those resulting from said photosensitive component (8) when said apparatus is applied to a standard surface.
Claim 12
Independent Claim
173 words
A method of assessing the degree of erythema or pigmentation of an area of skin of a warm-blooded animal which includes the steps of:-(i) applying to said area of skin an apparatus comprising a green light emitting diode (10) provided with an essentially constant electric current, and a light detector having a photosensitive electric component (8) connected to a conventional circuit for detecting and measuring light induced electrical changes in the photosensitive component (8), said diode (10) and photosensitive component (8) being situated and mutually screened within a holder which is generally closed apart from an aperture so that substantially all the light received by said photosensitive component (8) is that reflected from said area of skin via said aperture and having been emitted by said diode (10); (ii) measuring the electrical changes produced in the photosensitive electric component (8) resulting from the light reflected by said area of skin; and (iii) comparing said electrical changes with those resulting from said photosensitive component (8) when said apparatus is applied to a standard surface.
References Cited (Backward Citations)
No citation records indexed.
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