Apparatus and method for simultaneously detecting surface pressure and blood volume

Abstract

An apparatus for simultaneously detecting surface pressure and blood volume of an object and a method of detecting the same are provided. The apparatus includes a printed circuit board (PCB); a light emitter disposed on the PCB which emits light of a first wavelength and light of a second wavelength; a first light receiver which detects light of the first wavelength and a second light receiver which detects light of the second wavelength; a transparent elastic body on the PCB which covers the light emitter, the first light receiver, and the second light receiver; and a dichroic coating formed on the transparent elastic body. The dichroic coating reflects light of the first wavelength and transmits light of the second wavelength.

What is claimed is: 
     
         1 . An apparatus for simultaneously detecting a surface pressure and a blood volume of an object, the apparatus comprising:
 a printed circuit board (PCB);   a light emitter disposed on the PCB, the light emitter configured to emit light of a first wavelength and light of a second wavelength, different from the first wavelength;   a first light receiver disposed on the PCB, the first light receiver configured to detect light of the first wavelength;   a second light receiver disposed on the PCB, the second light receiver configured to detect light of the second wavelength;   a transparent elastic body disposed on the PCB and covering the light emitter, the first light receiver, and the second light receiver; and   a dichroic coating disposed on the transparent elastic body, wherein the dichroic coating reflects light of the first wavelength and transmits light of the second wavelength.   
     
     
         2 . The apparatus of  claim 1 , wherein the first wavelength is shorter than the second wavelength. 
     
     
         3 . The apparatus of  claim 2 , wherein the light of the first wavelength is green light and the light of the second wavelength is orange light. 
     
     
         4 . The apparatus of  claim 1 , wherein the light emitter is a laser diode. 
     
     
         5 . The apparatus of  claim 1 , wherein the transparent elastic body comprises one of silicon and a styrenic block copolymer. 
     
     
         6 . The apparatus of  claim 5 , wherein the transparent elastic body has a thickness in a range of about 2 mm to about 10 mm. 
     
     
         7 . The apparatus of  claim 5 , wherein the dichroic coating comprises metal. 
     
     
         8 . The apparatus of  claim 7 , wherein the dichroic coating comprises aluminum. 
     
     
         9 . The apparatus of  claim 1 , wherein
 the first light receiver comprises a first color filter disposed thereon, wherein the first color filter selectively transmits light of the first wavelength, and   the second light receiver comprises a second color filter disposed thereon, wherein the second color filter selectively transmits light of the second wavelength.   
     
     
         10 . The apparatus of  claim 1 , wherein the light emitter comprises a first light emitter configured to emit light of the first wavelength and a second light emitter configured to emit light of the second wavelength. 
     
     
         11 . The apparatus of  claim 10 , wherein
 the first light receiver and the second light receiver are a single light receiver configured to detect both light of the first wavelength and light of the second wavelength;   the first light emitter and the second light emitter are configured to alternately emit light of the first wavelength and light of the second wavelength; and   the single light receiver is configured to generate a first electrical signal in response to receiving the light of the first wavelength and is configured to generate a second electrical signal, distinguishable from the first electrical signal, in response to receiving light of the second wavelength.   
     
     
         12 . The apparatus of  claim 1 , wherein the object is a body part of a patient and the apparatus is configured to be wearable on the body part of the patient. 
     
     
         13 . A method of simultaneously detecting surface pressure and blood volume of an object, the method comprising:
 positioning a detecting apparatus such that a dichroic coating of the detecting apparatus is in contact with a skin of the object:   irradiating the dichroic coating with light of a first wavelength and irradiating the skin of the object, via the dichroic coating with light of a second wavelength, different form the first wavelength;   calculating a surface pressure of the object by detecting the light of the first wavelength that is reflected by the dichroic coating; and   calculating a blood volume by detecting the light of the second wavelength light that is scattered by the skin of the object and reflected back to the apparatus.   
     
     
         14 . The method of  claim 13 , wherein the calculating the surface pressure comprises measuring a curvature of the skin of the object by measuring an optical path of the detected light of the first wavelength based on an intensity of the detected light of the first wavelength. 
     
     
         15 . The method of  claim 13 , wherein the calculating the blood volume comprises calculating a change in the blood volume based on a change in an intensity of the detected light of the second wavelength. 
     
     
         16 . The method of  claim 13 , wherein the light of the first wavelength is green light, and the light of the second wavelength is orange light. 
     
     
         17 . A detecting apparatus comprising:
 a light emitter configured to emit light of a first wavelength and light of a second wavelength, different from the first wavelength;   a detector configured to detect light of the first wavelength and light of the second wavelength;   a transparent elastic body covering the light emitter and the detector; and   a dichroic coating disposed on the transparent elastic body, wherein the dichroic coating reflects light of the first wavelength emitted from the light emitter and transmits light of the second wavelength emitted from the light emitter.