Abstract:
Blood flow in capillary vessels can be observed by using a magnification ratio that can be altered by the magnification ratio adjustor without causing blurring so that zooming operations can be easily performed. An objective lens can easily be centered relative to a fingertip, for example, without causing a burden to patients by having the patients themselves move their fingertips to bring a desired image into focus. Heat dissipation from the illuminator can be facilitated, and the imaging units can be more compactly designed.

Description:
RELATED APPLICATIONS  
       [0001]     This application claims the benefit under 35 USC §120 of a parent Patent Cooperation Treaty application JP2004-261694 filed Mar. 16, 2004, published as kokai 2005-261494.  
       FIELD OF THE INVENTION  
       [0002]     The present disclosure generally relates to observing blood flow in capillary vessels in, for example, the nail epithelium of a fingertip. More particularly, the present disclosure relates to magnification ratio adjustment.  
       BACKGROUND  
       [0003]     Health care providers can observe the blood flow in capillary vessels of a patient in order to assess the health of the patient. Accordingly, a magnification device can be used to observe the fine details of the capillary vessels. However, the location and size of capillary vessels in a patient&#39;s finger, for example, can vary depending on the particular patient being observed. Magnification devices can adjust the magnification ratio (“zoom”) but often lose their focus when zooming. The loss of focus provides a distraction for the health care provider when zooming and panning across the capillary vessels of a patient.  
       SUMMARY OF THE INVENTION  
       [0004]     The present disclosure provides exemplary embodiments of the invention, which is defined by the claims as recited herein. In various embodiments, magnification ratio adjustment for observing blood flow in capillary vessels can be practiced using an apparatus that comprises a light source for illuminating, for example, a fingertip with light, and an optics imaging and processing component for producing an enlarged image of the fingertip. The enlarged image allows blood flow in a capillary vessel at the fingertip to be observed by a health care provider, for example.  
         [0005]     The optics imaging and processing component in the embodiment comprises a lens-barrel; a magnification ratio adjustor having an objective lens that is provided at the lower end of the lens-barrel ( 31 ) and an imaging component having an image sensor (such as a CCD, a CMOS sensor, and the like) and being provided at the upper end of the lens-barrel. The lens-barrel comprises an interval adjustment mechanism that is disposed between the imaging component and the lens-barrel in order to adjust the interval therebetween. The interval adjustment mechanism is arranged such that the focal point can be easily maintained when zooming using the interval adjustment mechanism.  
         [0006]     In another embodiment, the interval that extends from the objective lens to the image sensor is set by adjusting the interval between the imaging component and the lens-barrel with the interval adjustment mechanism, so that a focus point of the light passing through the magnification ratio adjustor matches the position of the image sensor.  
         [0007]     In yet another embodiment, the interval adjustment mechanism comprises a lower cylinder fixed to the lens-barrel and an upper cylinder fixed to the imaging component, where the upper cylinder is threadably mounted onto the outer or inner surface of the lower cylinder so that the interval can be set by rotating the upper cylinder in relation to the lower cylinder.  
         [0008]     In yet another embodiment, the optics processing and imaging component is mounted to a vertical pole having a supporting arm which allows the component to rotate on a horizontal plane that is perpendicular to the vertical pole and to move up or down along the vertical pole. The supporting arm comprises an X-axis stage, which allows the optics processing and imaging component to move in a horizontal direction perpendicular to the vertical pole, a Y-axis stage, which allows the component to move in another horizontal direction perpendicular to the horizontal direction, and a Z-axis stage, which allows the component to move in the vertical direction.  
         [0009]     In yet another embodiment, the illuminator comprises a light source provided in a housing having an opening for emitting the light from the light source to the outside of the housing through a condensing lens, and a fan for exhausting heat of the inside of the housing to the outside, the opening comprising an aperture mechanism of the light, and a mirror surface being provided on the opposite side of the opening.  
         [0010]     In yet another embodiment, the illuminator is provided with a mounting arm on the same base as the vertical pole. The mounting arm comprises two ball joints and a 360 degree-rotatable axis provided between the ball joints so that the illuminator can be placed in any desired orientation. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]     Non-limiting and non-exhaustive embodiments are described with reference to the following drawings.  
         [0012]      FIG. 1  is a perspective view that illustrates an apparatus for observing blood flow of capillary vessels.  
         [0013]      FIG. 2  illustrates a top view of the apparatus.  
         [0014]      FIG. 3  illustrates a side view from arrow III of  FIG. 1 .  
         [0015]      FIG. 4  illustrates a side view from arrow IV of  FIG. 1 .  
         [0016]      FIG. 5  illustrates a side view from arrow V of  FIG. 1 .  
         [0017]      FIG. 6  illustrates a view of a cross section of an optics processing and imaging section.  
         [0018]      FIG. 7  is an enlarged view of area A from  FIG. 6 .  
         [0019]      FIG. 8  illustrates a side view of a supporting arm.  
         [0020]      FIG. 9  illustrates an exploded perspective view of  FIG. 8 .  
         [0021]      FIG. 10  illustrates a sectional view of an illuminator.  
         [0022]      FIG. 11  is an illustration of a mounting arm.  
         [0023]      FIG. 12  is an illustration of an enlarged image of capillary blood vessels. 
     
    
     DETAILED DESCRIPTION  
       [0024]     Various embodiments will be described in detail with reference to the drawings, where like reference numerals represent like parts and assemblies throughout the several views. Reference to various embodiments does not limit the scope of the invention, which is limited only by the scope of the claims attached hereto. Additionally, any examples set forth in this specification are not intended to be limiting and merely set forth some of the many possible embodiments for the claimed invention.  
         [0025]     Throughout the specification and claims, the following terms take at least the meanings explicitly associated herein, unless the context clearly dictates otherwise. The meanings identified below are not intended to limit the terms, but merely provide illustrative examples for use of the terms. The meaning of “a,” “an,” and “the” may include reference to both the singular and the plural. The meaning of “in” may include “in” and “on.” The term “coupled” can mean a direct connection between items, an indirect connection through one or more intermediaries, or communication between items in a manner that may not constitute a connection.  
         [0026]     Briefly stated, the present disclosure generally relates to observing blood flow in a capillary vessel. An apparatus for observing blood flow in a capillary vessel is arranged having a first length that extends from an objective lens to an image sensor, so that a focus point of the light passing through the magnification ratio adjustor  922  is focused upon the image sensor. However, because it is difficult, in practice, to assemble the optics processing and imaging component with sufficiently strict tolerances, an error may occur with respect to a first length “L” (see  FIG. 6 , for example) that extends from the objective lens to the image sensor.  
         [0027]     Accordingly, when a user changes a magnification ratio with the magnification ratio adjustor (such as when zooming in or out), a shift of a focus point may result which causes the desired image to be out of focus. Conventional methods often include an additional focusing step which is conducted by moving of an optics processing and imaging component in an up or down direction. However, this operation provides a distraction and requires extra care for dealing with the tedious operation of maintaining focus.  
         [0028]      FIG. 1  is a perspective view that illustrates an apparatus for observing blood flow of capillary vessels.  FIG. 2  illustrates a top view of the apparatus.  FIG. 3  illustrates a side view from arrow III of  FIG. 1 .  FIG. 4  illustrates a side view from arrow IV of  FIG. 1 .  FIG. 5  illustrates a side view from arrow V of  FIG. 1 .  
         [0029]     In an embodiment, an apparatus  1  comprises a light source  2  for illuminating a fingertip with light, and an optics imaging and processing component  3  for producing an enlarged image of the fingertip. The enlarged image allows blood flow in a capillary vessel at the fingertip to be observed by a health care provider, for example, viewing a display (not shown).  
         [0030]     The optics imaging and processing component  3  in the embodiment comprises a lens-barrel; a magnification ratio adjustor having an objective lens that is provided at the lower end of the lens-barrel  31  and an imaging component having an image sensor (such as a CCD, a CMOS sensor, and the like) and being provided at the upper end of the lens-barrel. The lens-barrel  31  comprises an interval adjustment mechanism  7  that is disposed between the imaging component and the lens-barrel in order to adjust the interval therebetween. The interval adjustment mechanism  7  is arranged such that the focus point can be easily maintained when zooming using the interval adjustment mechanism.  
         [0031]     Optical processing/imaging component  3  is mounted to vertical pole  42  with supporting arm  5 , the vertical pole  42  being provided on base  41  in a vertical direction. Illuminator  2  is mounted on the base  41  with mounting arm  6 .  
         [0032]     The optics processing and imaging component  3 , as shown in  FIG. 6  (which is a partly-sectional view of the whole part of the component), is configured to have a lens-barrel with a cavity of the inside, magnification ratio adjustor  32  with a objective lens (not shown in figures), and imaging component  33  with CCD  331  (as discussed above other imaging sensors can be used). The example apparatus in various embodiments further comprises interval adjustment mechanism  7  in optical processing/imaging component  3 . As shown in  FIGS. 6 and 7  (which is an enlarged view of part A from  FIG. 6 ), the interval adjustment mechanism  7  is provided between lens-barrel  31  and imaging component  33  so that the interval X can be adjusted.  
         [0033]     Interval adjustment mechanism  7  comprises lower cylinder  71  that is attached to lens-barrel  31 , and upper cylinder  72  that is attached to imaging component  33 . Upper cylinder  72  is threadably mounted onto the outer surface of lower cylinder  71  (for example, through a spiral screw mechanism) so that the upper cylinder can move in a longitudinal direction (as shown by arrow B) as it rotates in relation to lower cylinder  71 . In other words, interval adjustment mechanism  7  can be configured to alter interval X by rotating upper cylinder  72 . Section  70  is helically driven. Both cylinders  71  and  72  are designed not to obstruct light passing from magnification ratio adjustor  32  to a sensor, such as CCD  331 .  
         [0034]     In the embodiment, a first interval L from the object lens of magnification ratio adjustment  32  to CCD  331  is adjustable to match with a reference interval by adjusting interval X by using interval adjustment mechanism  7 . The term “reference interval” references the interval that extends from an objective lens to a sensor, which is determined in its design so that a focus point of the light passing through magnification ratio adjustor  32  is focused upon the sensor. In many cases, the apparatus  1  has an error in dimension L when assembled (due to imprecise tolerances, for example). The manufacturing error can be corrected by adjusting interval X by using interval adjustment mechanism  7 .  
         [0035]      FIG. 8  illustrates a side view of supporting arm  5 .  FIG. 9  illustrates an exploded perspective view of  FIG. 8 . Arrows in  FIG. 9  indicate a Y-axis direction, an X-axis direction, and a Z-axis direction. The X-axis is one of the horizontal directions, the Y-axis is another horizontal direction that is perpendicular to the X-axis direction (and that defines a horizontal plane comprising the X and Y axes), and Z-axis is the vertical direction. Supporting arm  5  includes a first stage  51 , a second stage  52 , a third stage  53 , and a forth stage  54 . Supporting arm  5  is mounted on vertical pole  42  with the first stage  51  and also supports optics processing and imaging component  3  with the forth stage  54 .  
         [0036]     The first stage  51  has an aperture  511  into which vertical pole  42  can be inserted. First stage  51  can be affixed to vertical pole  42  inserted through the penetration hole  511  by tightening first knob  512 , and can also be rotatably mounted in a horizontal direction and moved up and down by loosening first knob  512 . The first stage  51  also has a second knob  513  and a third knob  514 . The first stage  51  further has a first recessed portion (or concave)  515  that generally extends in the Z-axis direction. The first recessed portion typically has a wider bottom than its opening.  
         [0037]     The second stage  52  has a first convex portion  512  stretching in the Z-axis direction, the shape of which slideably fits that of the first recessed portion  515  of the first stage  51 , and a second convex portion  522  extending in the X-axis direction. Both the convex portions  512  and  522  typically have wider top surfaces than the bottom surfaces.  
         [0038]     The third stage  53  has a second recessed portion  531  stretching in the X-axis direction, and a third recessed portion  532  stretching in the Y-axis direction. Both recessed portions  531  and  532  have wider bottoms than their openings. The shape of the second recessed portion  531  slideably fits that of the second convex portion  522 . The third stage  53  has a forth knob  533  and a fifth knob  534 .  
         [0039]     The forth stage  54  has an aperture  541  for holding the optics processing and imaging component  3 . Stage  54  also has a third convex portion  542 , the shape of which slideably fits that of the third recessed portion  532  of the third stage  53 .  
         [0040]     Accordingly, first, second, third and forth stages  51 - 54  can be coupled to supporting arm  5  as an assembly when the first convex portion  521  and the first recessed portion  515  are joined together, the second convex portion  522  and the second recessed portion  531  are joined together, and the third convex portion  542  and the third recessed portion  532  are joined together. The Z-axis stage can be coupled to the first convex portion  521  to allow rotation of an axis (not shown in figures) of the second and third knobs  513  and  514  as a rack and pinion mechanism. The second knob  513  can have a smaller number of pinions than that of the third knob  514  (those pinions are not shown in figures).  
         [0041]     The X-axis stage can be provided with a linkage of the convex portion  522  to rotation of an axis (not shown) of the forth knob  533  as a rack and pinion mechanism. The Y-axis stage can be provided with a linkage of the third convex portion  542  to rotation of an axis (not shown) of the fifth knob  534  as a rack and pinion mechanism. In the example structures of the supporting arm  5 , second stage  52  moves along the Z-axis direction in relation to the first stage  51  as the second knob  513  or the third knob  514  is rotated. The third stage  53  moves along the X-axis direction in relation to the second stage  52  as the forth knob is rotated, and the stage part  54  moves along the Y-axis direction in relation to the third stage  53  as the fifth knob  534  is rotated. With respect to adjustment using the second and third knobs  513  and  514 , a rotation of the third knob  514  can provide a smaller amount of the movement in the Z-axis direction as compared to the amount of rotation provided by the second knob.  
         [0042]      FIG. 10  illustrates a sectional view of illuminator  2 . In an embodiment, illuminator  2  comprises a housing body  21 , a light source  22  provided in the housing  21 , an opening  23  for emitting the light from the light source  22  to the outside of the housing  21  through a condensing lens  231 , and a fan  24  and air inlet  25  for exhausting heat of the inside of the housing  21  to the outside. The opening  23  typically has an aperture mechanism of the passing light (not shown). On the opposite side to the opening a coating of mirror surface is applied. The light source  22  can be, for example, a high pressure mercury lamp.  
         [0043]     The illuminator  2  is mounted on the base  41  with a mounting arm  6  as shown in  FIG. 11 . The mounting arm has two ball joints  61 ,  62 , and a 360 degree-rotatable axis  63  provided between the two ball joints. The ball joint  61  is also coupled with an edge  64  that can be fixed to the base  41 . The ball joint  62  is also coupled with another edge  65  that can be fixed to the illuminator  2 . A lock dial  66  can be provided on one end of the rotatable axis  63 . The mounting arm  6  can be configured to lock any movements related to the joint balls  61 ,  62  the rotatable axis  63 , and the parts of arm  67 ,  68  when the lock dial  66  is tightened.  
         [0044]     In operation, apparatus  1  can be used as follows. The fingertip of a subject to be tested can be placed on a finger holder  9  as shown in  FIG. 3 . The illuminator is typically adjusted so that the fingertip on the holder  9  can be successfully exposed to the light (for example, by use of rotations at the joint ball  61 ,  62  and the axis  63 ). The illuminator can be fixed in a desired position by tightening of the lock dial  66 . When the lock dial  66  is tightened, the first knob  512  can be loosened so the supporting arm  5  can be used to move the optics processing and imaging component  3  to where the component  3  is placed above the fingertip on the holder.  
         [0045]     The fingertip on the holder  9  can be illuminated by turning on the light source  22  of the illuminator  2 , while focusing the light from the source  22  through an aperture mechanism in the opening  23 . A fan  24  can also be used to cool the illuminator  2 . The objective lens of the magnification ratio adjustor  32  can be brought to a desired location adjacent to the fingertip on the holder  9  by sliding the second stage  52  with respect to the first stage  51  along the Z-axis direction by rotation of the second knob  513  or the third knob  514 , and/or sliding of the third stage  53  with respect to the second stage  52  along the X-axis direction by rotation of the forth knob  533 , and/or sliding of the forth stage  54  with respect to the third stage  53  along the Y-axis direction by rotation of the fifth knob  534 . The magnification ratio (such as when zooming is) can be performed by using the magnification ratio adjustor  32 . An image of the enlarged capillary vessels can be seen as illustrated by  FIG. 12 .  
         [0046]     Although the invention has been described herein by way of exemplary embodiments, variations in the structures and methods described herein may be made without departing from the spirit and scope of the invention. For example, the positioning and/or sizing of the various components may be varied. Individual components and arrangements of components may be substituted as known to the art. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention is not limited except as by the appended claims.