APPARATUS FOR PHOTOELECTRIC DERMACHROMOGRAPHY

• US 3,602,213 A
• Filed: 02/13/1968
• Issued: 08/31/1971
• Est. Priority Date: 02/13/1968
• Status: Expired due to Term

• Current Assignee: William B. Leaf, William L. Howell
• Original Assignee: William B. Leaf, William L. Howell
• Inventors: Howell, William L., Leaf, William B.
• Primary Examiner(s): Oechsle, Anton O.
• Application Number:
  US04/705,209
• Time in Patent Office: 1,295 Days
• Field of Search: 128/2.5P,2.5R,2.5NC,2.5F,2.5PR,2.5T 250/217,227,239
• US Class Current: 600/479
• CPC Class Codes: A61B 5/02416 using photoplethysmograph signals, e.g. generated by infrared radiation A61B5/14552 takes precedence
• CPC Class Codes: A61B 5/0261 using optical means, e.g. infrared light

Abstract

A method and apparatus for detecting occlusions in one of the internal carotid arteries by the differential sensing of epidermal blood flow in the supraorbital areas. A pair of photoelectric transducers that sense the relative absorption or reflection of light by the blood at the surface of the skin as an indication of blood flow are positioned over the supraorbital notches above the eyes. The blood contributions to these areas from the superficial temporal, angular and occipital arteries are eliminated by compression, leaving the internal carotids as the only suppliers. The sensor outputs are then compared, and any unbalance indicates an occlusion in one of the carotid arteries. Same may also be detected by momentarily compressing the supraorbital areas as well, and then comparing the refilling curves produced by the sensors. The location of the occlusion above or below the carotid bifurcation may be determined by removing all compression and repositioning the transducers to sense the external carotid flows.

Claims

1. Apparatus for photoelectric dermachromography including, in combination, a transducer unit adapted to be removably attached to a skin area in which the blood flow is to be measured, means for removably attaching the transducer unit to a skin area which is pressureless with respect to the skin area and is operable to maintain said transducer removably fixed to the skin area and maintain said unit on the skin area preventing sliding movement with respect thereto, electric light sensitive means disposed in said transducer, a light source, and ringlike means in said transducer for conducting light rays from said light source to the skin annularly about said electric light sensitive means, said electric light sensitive means being disposed in said transducer in position therein in the path of light reflected from the skin area, and an electric circuit controlled by said electric light sensitive means.

2. Apparatus for photoelectric dermachromography in accordance with claim 1, wherein said means for removably attaching said transducer unit to a skin area comprises a transparent adhesive adapted to be removably fixed to the skin area and fixed to at least the lower surface of said ringlike means.

3. Apparatus for photoelectric dermachromography including, in combination, a transducer unit adapted to be removably attached to a skin area in which the blood flow is to be measured, electric light sensitive means disposed in said transducer, a light source, and a continuously annular ringlike means in said transducer conducting light rays from said light source to the skin in a continuously extending annulus about said light sensitive means, said light source being so positioned in said transducer unit relative to said ringlike means that light may be transmitted from said light source to the skin solely by said ringlike means, said electric light sensitive means being disposed in said transducer unit in position therein in the path of light reflected from the skin area, and an opaque housing of generally inverted cuplike form, and said light source, said ringlike means for directing light from said light source, and said electric light sensitive means are disposed in concentric relation in said housing, said ringlike means being provided with a body and an annular skirt depending therefrom, said body being provided with a duct extending therethrough and said light source being positioned in said duct and said electric light sensitive means being in position encompassed by said annular skirt, and further opaque means positioned between said light source and said electric light sensitive means for preventing light from said light source from directly impinging on said electric light sensitive means, said opaque housing comprising a top portion having an annular skirt depending therefrom, and said further opaque means comprises a reflective casing having an open lower side, and the lower annular edges of said annular skirt of the opaque housing and of the annular skirt of the ringlike means for conducting light, and the lower edge of said casing are in substantially the same horizontal plane, adhesive means applied to said lower edges for removably securing the transducer unit to the skin, and an electric circuit controlled by said electric light sensitive means.

4. Apparatus for photoelectric dermachromographY including, in combination a transducer unit adapted to be removably attached to a skin area in which the blood flow is to be measured, electric light sensitive means disposed in said transducer, a light source, means in said transducer unit for conducting light from said light source to the skin area adjacent said electric light sensitive means, said electric light sensitive means being so positioned in said transducer relative to said means for conducting light that it is in position adapted to receive light reflected from the skin area, means for removably attaching said transducer unit to a skin area and said last-named means adapted to be positioned between the electric light sensitive means and the skin, and an electric circuit controlled by said electric light sensitive means.

5. Apparatus for photoelectric dermachromography according to claim 4, wherein said transducer unit comprises an opaque band having an operative surface adapted to be removably attached to a skin area in which the blood flow is to be measured, said light sensitive means comprising a plurality of spaced apart electric light sensitive means mounted on the other surface of said band, the band having areas beneath each light sensitive means for the passage of reflected light therethrough to a light sensitive means, said light conducting means comprising an optical system mounted on said other surface of said band for conducting light from said light source and emitting the light at a plurality of stations on said band, each of said stations of said plurality of stations being adjacent one electric light sensitive means, said band having areas adjacent each station of the optical system for transmission of light therefrom to the skin area beneath each electric light sensitive means for the reflection of said light from the skin to each electric light sensitive means, said electric circuit having means for detachably connecting each of said electric light sensitive means, serially, into said electric circuit, and said electric circuit being controlled by the electric light sensitive means which is connected into said circuit.

6. Apparatus for Photoelectric dermachromography in accordance with claim 5, wherein each of said stations is equally spaced from its respective electric light sensitive means.

7. Apparatus for Photoelectric dermachromography in accordance with claim 5, wherein said opaque band is flexible.

8. Apparatus for Photoelectric dermachromography in accordance with claim 5, wherein said electric light sensitive means are longitudinally spaced apart on said band.

9. Apparatus for Photoelectric dermachromography in accordance with claim 5, wherein said attaching means comprises a transparent adhesive adhered to the operative surface of said opaque band for removably attaching the band to the skin.

10. Apparatus for Photoelectric dermachromography in accordance with claim 5, wherein said optical system includes a manifold for gathering and transmitting light from said light source, and a plurality of light pipes each positioned to receive and conduct light from said manifold to a station adjacent an electric light sensitive means, there being a light pipe for each electric light sensitive means.

11. Apparatus for Photoelectric dermachromography in accordance with claim 10, wherein said light pipes are flexible.