Abstract:
An apparatus and method for measuring a contact pressure and a method of manufacturing the apparatus. The apparatus includes: a material layer configured to provide a light path along which incident light travels to a subject being in contact with the material layer; a spectrum analyzer configured to detect light emitted from the material layer and perform a light absorption spectrum analysis on the detected light to determine an intensity of the detected light; and a pressure calculator configured to determine the contact pressure of the subject based on the determined intensity.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority from Korean Patent Application No. 10-2014-0119371, filed on Sep. 5, 2014 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference. 
       BACKGROUND 
       [0002]    1. Field 
         [0003]    Apparatuses and methods consistent with exemplary embodiments relate to obtaining data generated by contacting a subject, and more particularly to, a contact pressure measuring apparatus, a method of measuring contact pressure using the apparatus and a method of manufacturing the apparatus. 
         [0004]    2. Description of the Related Art 
         [0005]    Various types of data regarding a subject may be obtained when diagnosing the subject. However, when the subject is a living body, the subject may move during a diagnosis process, and thus desired information regarding the subject may be affected due movement of the subject when diagnosis is performed. 
         [0006]    Accordingly, the reliability of information obtained through diagnosis may be increased by correcting the information or by using a correction system embedded in a diagnosis device during the diagnosis. 
         [0007]    An example of information obtained through a subject diagnosis process may be subject contact pressure. The accuracy of measured data may be increased by consistently maintaining the subject contact pressure. The subject contact pressure may be currently measured in a mechanical way. 
       SUMMARY 
       [0008]    One or more exemplary embodiments provide an apparatus for measuring contact pressure in an optical way. 
         [0009]    Further, one or more exemplary embodiments provide a method of manufacturing apparatuses for measuring contact pressure in an optical way. 
         [0010]    Further still, one or more exemplary embodiments provide a method of measuring contact pressure using the apparatuses for measuring contact pressure in an optical way 
         [0011]    According to an aspect of an exemplary embodiment, there is provided an apparatus for measuring contact pressure, the apparatus including: a material layer configured to provide a light path along which incident light travels to a subject being in contact with the material layer; a spectrum analyzer configured to detect light emitted from the material layer and perform a light absorption spectrum analysis on the detected light to determine an intensity of the detected light; and a pressure calculator configured to determine the contact pressure of the subject based on the determined intensity. 
         [0012]    The spectrum analyzer and the pressure calculator may be mounted on a same substrate. 
         [0013]    The pressure calculator may be separately independently provided from the material layer and the spectrum layer. The apparatus may further include a substrate on which the spectrum analyzer is mounted, and the pressure calculator is provided outside the substrate, the pressure calculator is electrically connected to the spectrum analyzer through the substrate. The apparatus may further include a substrate on which the spectrum analyzer is mounted, a contact pad formed on the substrate, wherein the pressure calculator is electrically connected to the spectrum analyzer through the contact pad. 
         [0014]    The spectrum analyzer may include light absorption spectrum data measured at various contact pressures. 
         [0015]    The pressure calculator may include mapping data indicating relation between a plurality of contact pressure values and a corresponding plurality of light intensity values. 
         [0016]    The material layer may be an attenuated total reflectance (ATR) crystalline layer. 
         [0017]    The apparatus may further include a light source configured to emit the incident light to the material layer with an incidence angle and adjust the incidence angle to be greater than a critical angle to occur total internal reflection. 
         [0018]    The spectrum analyzer may be further configured to perform the light absorption spectrum analysis based on a wavelength or a range of wavelengths of the detected light, and the pressure calculator may be further configured to consider the wavelength or the range of wavelengths of the detected light to determine the contact pressure. 
         [0019]    According to an aspect of another exemplary embodiment, there is provided a method of manufacturing a contact pressure measuring apparatus, the method including: providing a light source and a spectrum analyzer on a substrate; forming, on the substrate, a structure that covers the light source and the spectrum analyzer; forming a material layer which is disposed on a surface of the structure and has a total reflection characteristic; and providing a pressure calculator connected to the spectrum analyzer. 
         [0020]    The pressure calculator may be provided on the substrate. 
         [0021]    The pressure calculator may be provided outside the substrate. 
         [0022]    The structure may be a housing or a material layer. When the structure is the housing, the surface of the structure may correspond to a ceiling of the housing and the structure is mounted on the substrate to cover the light source and the spectrum analyzer. 
         [0023]    The method may further include: when the structure is the material layer, forming a groove to mount the material layer thereon; and attaching the material onto the groove. 
         [0024]    According to an aspect of another exemplary embodiment, there is provided a method of a contract pressure measuring apparatus, the method including: detecting a light absorption spectrum with respect to a subject; analyzing the detected light absorption spectrum; obtaining light intensity data that corresponds to a result of the analyzing; and outputting a pressure value corresponding to the obtained light intensity data. 
         [0025]    The detecting the light absorption spectrum may include: recognizing that a material layer of the apparatus is in contact with the subject; radiating light into the material layer; and detecting light emitted through a light emission surface of the material layer. 
         [0026]    The method may further include: displaying the output pressure value on a display. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0027]    The above and/or other aspects will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings in which: 
           [0028]      FIG. 1  is a block diagram of a subject contact pressure measuring apparatus according to an exemplary embodiment; 
           [0029]      FIG. 2  is a detailed diagram of the subject contact pressure measuring apparatus of  FIG. 1  according to an exemplary embodiment; 
           [0030]      FIG. 3  is a cross-sectional view of a subject pressure measuring apparatus including a pressure calculator of  FIG. 2  that is connected to a substrate and independently separate from other elements, according to an exemplary embodiment; 
           [0031]      FIG. 4  is a cross-sectional view of a pressure measuring apparatus including a pressure calculator of  FIG. 2  that is connected to a spectrum analyzer through a contact pad and independently separate from other elements, according to an exemplary embodiment; 
           [0032]      FIGS. 5 through 7  are cross-sectional views of a subject contact pressure measuring apparatus for explaining a method of manufacturing the subject contact pressure measuring apparatus according to an exemplary embodiment; and 
           [0033]      FIG. 8  is a flowchart of a method of measuring a subject contact pressure by using an apparatus for measuring subject contact pressure according to an exemplary embodiment. 
       
    
    
     DETAILED DESCRIPTION 
       [0034]    Exemplary embodiments are described in greater detail below with reference to the accompanying drawings. 
         [0035]    In the following description, like drawing reference numerals are used for like elements, even in different drawings. The matters defined in the description, such as detailed construction and elements, are provided to assist in a comprehensive understanding of the exemplary embodiments. However, it is apparent that the exemplary embodiments can be practiced without those specifically defined matters. Also, well-known functions or constructions are not described in detail since they would obscure the description with unnecessary detail. 
         [0036]    An subject contact pressure measuring apparatus using optical absorptivity of subject(hereinafter, a pressure measuring apparatus) according to an exemplary embodiment will be described as well as a method of manufacturing the pressure measuring apparatus and a method of measuring subject contact pressure using the pressure measuring apparatus. 
         [0037]    First, a pressure measuring apparatus according to an embodiment is described. 
         [0038]      FIG. 1  is a block diagram of a pressure measuring apparatus  100  according to an exemplary embodiment. 
         [0039]    As shown in  FIG. 1 , the pressure measuring apparatus  100  includes a light source  20 , an attenuated total reflectance (ATR) device  30  including a total reflection material layer, a spectrum analyzer  40 , and a pressure calculator  50 . The light source  20  radiates light onto the ATR device  30 . The light source  20  may be, for example, a laser light source, a light-emitting diode (LED), etc. The laser light source may be a semiconductor laser. The light radiated onto the ATR device  30  from the light source  20  may be transferred to the spectrum analyzer  40  through internal total reflection. Specifically, the ATR device  30  may include a crystal of a high refractive index, and light incident on the ATR device  30  may undergo multiple internal reflections in the crystal and be collected by the spectrum analyzer  40  as it exits the crystal. When a subject is in contact with the ATR device  30  during the internal total reflections, a part of the light is absorbed by the subject and the remaining light is transferred to the spectrum analyzer  40 . That is, a light absorption spectrum of the subject is transferred to the spectrum analyzer  40 . A spectrum of the light transferred to the spectrum analyzer  40  may be analyzed so that data of the spectrum intensity (for example, the intensity of light having a wavelength) of the transferred light may be output. The spectrum of the transferred light may be analyzed by using a specific wavelength or a range of wavelengths that belongs to a spectrum range. For example, the intensity of light corresponding to the specific wavelength or the range of wavelengths may be analyzed from the spectrum of the transferred light and data of the intensity of the light having the specific wavelength or the range of wavelengths may be output. The specific wavelength or the range of wavelengths may correspond to a wavelength having no an optical reaction (for example, light absorption) or having a minimum optical reaction with structure (or chemical) constituting the subject. 
         [0040]    The output data is transferred to the pressure calculator  50 . The pressure calculator may be implemented by a processor and a memory. The pressure calculator  50  calculates pressure from the data transferred from the spectrum analyzer  40  based on a predetermined algorithm. The calculated pressure is subject contact pressure with respect to the pressure measuring apparatus  100  (or the ATR device  30 ). Data of the light absorption spectrum of the subject measured at various contact pressures may be stored in the spectrum analyzer  40  during a process of manufacturing the pressure measuring apparatus  100 . The spectrum analyzer  40  may compare and analyze the light absorption spectrum transferred from the ATR device  30  by using the stored data as a database to obtain data regarding the intensity of the light absorption spectrum at a specific location. 
         [0041]    The pressure calculator  50  may store data of the intensity of the light absorption spectrum-the contact pressure based on data regarding the intensity of the light absorption spectrum of the subject that is measured at various contact pressures and data regarding the various contact pressures during the process of manufacturing the pressure measuring apparatus  100 . Specifically, the pressure calculator  50  may use mapping data indicating relation between a plurality of contact pressure values and a corresponding plurality of light intensity values. Thus, if the intensity of a predetermined location of the light absorption spectrum of the subject is provided to the pressure measuring apparatus  100 , the subject contact pressure may be output. The pressure measuring apparatus  100  may include a display window to display the output subject contact window. Alternatively, the pressure measuring apparatus  100  may transfer data regarding the output subject contact pressure to a display  200  that is spaced apart therefrom to display the output subject contact pressure on the display  200 . 
         [0042]      FIG. 2  is a detailed diagram of the pressure measuring apparatus  100  of  FIG. 1 . 
         [0043]    As shown in  FIG. 2 , a light source  62 , a spectrum analyzer  64 , and a pressure calculator  66  are provided on a substrate  60 . The substrate  60  may be, for example, a printed circuit board. The spectrum analyzer  64  may be provided at a location facing a light emission surface  68 S 2  of an ATR crystalline layer  68 . The spectrum analyzer  64  may detect and analyze light emitted from the light emission surface  68 S 2  of the ATR crystalline layer  68 . The spectrum analyzer  64  and the pressure calculator  66  are spatially spaced apart from each other but are electrically connected to each other. That is, the spectrum analyzer  64  and the pressure calculator  66  may be connected to each other by an electric wiring for data transfer. The light source  62  may be, for example, a laser diode (LD), an LED, etc. but is not limited thereto. An incident angle of light incident onto a light incident surface  68 S 1  of the ATR crystalline layer  68  from the light source  62  may be an angle at which the light incident onto the ATR crystalline layer  68  makes total reflection in upper and lower surfaces of the ATR crystalline layer  68 . For example, if the incident angle of the light is adjusted to be greater than a critical angle, the light does not cross the boundaries of the ATR crystalline layer  68  and be totally reflected back internally. Here, the critical angle refers to an angle above which total internal reflection occurs. 
         [0044]    When a subject  72  contacts the upper surface of the ATR crystalline layer  68 , a total reflection condition for the upper surface of the ATR crystalline layer  68  may differ than when the subject  72  is not in contact with the ATR crystalline layer  68 . For example, a part of the light incident onto the upper surface of the ATR crystalline layer  68  is absorbed by the subject  72 , and the remaining light is reflected into the ATR crystalline layer  68 . The light reflected into the ATR crystalline layer  68  is totally reflected from the lower surface of the ATR crystalline layer  68 . The light incident in the ATR crystalline layer  68  transmits the ATR crystalline layer  68  in the manner described above and is emitted through the light emission surface  68 S 2 . The light emitted through the light emission surface  68 S 2  of the ATR crystalline layer  68  includes light absorption information regarding a plurality of regions of the subject  72 . Thus, the spectrum analyzer  64  may detect the light emitted through the light emission surface  68 S 2  of the ATR crystalline layer  68  and extract light intensity data regarding a specific location of an absorption spectrum of the detected light through spectrum analysis. The extracted light intensity data is transferred to the pressure calculator  66  via the electric wiring. The pressure calculator  66  analyzes the light intensity data transferred from the spectrum analyzer  64  and outputs contact pressure corresponding to the light intensity data. 
         [0045]    A structure  70  may cover the light source  62 , the spectrum analyzer  64 , and the pressure calculator  66 . When the structure  70  is a housing (or a case), the ATR crystalline layer  68  may be attached to a ceiling of the structure  70 . A part of the structure  70  contacting the ATR crystalline layer  68  may be transparent. 
         [0046]    According to another example, the structure  70  is not the housing and may be a material layer covering the light source  62 , the spectrum analyzer  64 , and the pressure calculator  66  and may include a groove for mounting the ATR crystalline layer  68 . In this case, a refractive index of the structure  70  may be smaller than that of the ATR crystalline layer  68  that may be mounted in the groove. The ATR crystalline layer  68  may be an example of a material layer exhibiting an ATR characteristic. 
         [0047]    The pressure calculator  66  may be separate from other elements including the substrate  60  and may be independently provided as the examples illustrated in  FIGS. 3 and 4 . 
         [0048]    As shown in  FIG. 3 , the pressure calculator  66  is present outside the substrate  60  and the structure  70 . The pressure calculator  66  may be electrically connected to the substrate  60 . Thus, the pressure calculator  66  may be electrically connected to the spectrum analyzer  64  through the substrate  60 . 
         [0049]    As shown in  FIG. 4 , the pressure calculator  66  disposed outside the substrate  60  and the structure  70  may be electrically connected to the spectrum analyzer  64  through a contact pad  80  provided on the substrate  60 . The contact pad  80  is spatially spaced apart from the spectrum analyzer  64  but is electrically connected thereto. The pressure calculator  66  of  FIGS. 3 and 4  may be provided with a display apparatus on which contact pressure output by the pressure calculator  66  is displayed. 
         [0050]    A method of manufacturing a pressure measuring apparatus, according to an embodiment, will now be described with reference to  FIGS. 5 through 7 . The same reference numerals denote the same elements throughout. 
         [0051]    As shown in  FIG. 5 , the light source  62 , the spectrum analyzer  64 , and the pressure calculator  66  are mounted on the substrate  60 . The light source  62  and the spectrum analyzer  64  may be disposed in consideration of locations of light incident and emission surfaces of the ATR crystalline layer  68 . The pressure calculator  66  may not be mounted on the substrate  60  but may be separately provided outside the substrate  60  (see  FIGS. 3 and 4 ). 
         [0052]    As shown in  FIG. 6 , the structure  70  that covers the light source  62 , the spectrum analyzer  64 , and the pressure calculator  66  are formed on the substrate  60 . When the structure  70  is a housing, the ATR crystalline layer  68  is attached to a ceiling of the structure  70  before the structure  70  is mounted on the substrate  60 . Thereafter, the structure  70  may be mounted in such a way that the ATR crystalline layer  68  is disposed between the light source  62  and the spectrum analyzer  64 . When the structure  70  is a material layer having a refractive index that is smaller than that of the structure  70 , as shown in  FIG. 7 , the structure  70  that covers the light source  62 , the spectrum analyzer  64 , and the pressure calculator  66  is formed on the substrate  60 , and then a groove  68 G for attaching the ATR crystalline layer  68  is formed in a location on which the ATR crystalline layer  68  of the structure  70  is to be attached. In this regard, one side of an inclination surface of the groove  68 G is parallel to the light incident surface of the ATR crystalline layer  68 , and the other side thereof is parallel to the light emission surface of the ATR crystalline layer  68 . After the groove  68 G is formed, the ATR crystalline layer  68  is attached into the groove  68 G of the structure  70 . In this regard, an adhesive agent that does not prevent light from being incident and emitted may be used to attach the ATR crystalline layer  68  into the groove  68 G. A refractive index of the adhesive agent is smaller than that of the ATR crystalline layer  68 . 
         [0053]    A method of measuring subject contact pressure by using the pressure measuring apparatus  100  according to an embodiment will now be described with reference to  FIGS. 1 and 8 . 
         [0054]    As shown in  FIG. 8 , light is radiated onto the subject  72  (operation S 1 ) through the ATR crystalline layer  68  of the pressure measuring apparatus  100 . Light incident onto the ATR crystalline layer  68  with an incident angle between the light incident surface  6851  of the ATR crystalline layer  68  and the line perpendicular to the light incident surface  68 S 1  is reflected from an upper surface of the ATR crystalline layer  68  and a part of the light is absorbed by the subject  72 . In this regard, degree of light absorption of the subject  72  may differ according to contact pressure of the subject  72  contacting the ATR crystalline layer  68 . 
         [0055]    Thereafter, a light absorption spectrum with respect to the subject  72  is measured (detected) (operation S 2 ). In more detail, the light incident onto the ATR crystalline layer  68  is repeatedly reflected from upper and lower surfaces of the ATR crystalline layer  68  and is emitted through the light emission surface  68 S 2  of the ATR crystalline layer  68 . During the process, part of the light incident on the upper surface of the ATR crystalline layer  68  is absorbed by the subject  72 . Thus, the light emitted through the light emission surface  68 S 2  of the ATR crystalline layer  68  includes light absorption information of the subject  72 . The light emitted through the light emission surface  68 S 2  of the ATR crystalline layer  68  is incident onto and detected by the spectrum analyzer  64 . The spectrum analyzer  64  analyzes a spectrum of the detected light (operation S 3 ). Light intensity data of a predetermined location of the spectrum of the detected light may be determined by the spectrum analysis. Contact pressure is output by the light intensity data obtained through the spectrum analysis (operation S 4 ). The contact pressure may be output by using a program that uses a light intensity-contact pressure database. The output contact pressure may be a contact pressure of the subject  72 . 
         [0056]    The subject  72  provided in the pressure measuring apparatus and the manufacturing and measuring methods described above may be, for example, the skin of a living body, a finger, a toe, etc. but is not limited thereto. 
         [0057]    An apparatus for measuring subject contact pressure, according to at least one embodiment, measures the subject contact pressure by using a change in light absorption of a subject. Thus, a configuration of the apparatus may be simpler than that of an existing mechanical apparatus, and the reliability of measured data may be increased.