JP2012071036A - Structure and method for calibration for calibrating blood component measuring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce more measurement errors of a blood component measuring device by calibrating with a structure for calibration and to improve its measurement accuracy.SOLUTION: The structure 10 for calibration includes a body part 24 having a light scatterer 22 therein and a flow cell 28 filled with a calibration liquid 26. The flow cell 28 comprises a transmitter 40 to transmit a near-infrared light irradiated from a light emission part 18 of the blood component measuring device 12 and a tube 42 to be connected to the transmitter 40. A transmission part includes a first transmission part 44 with a short optical path length of the near-infrared light and a second transmission part 46 with a long optical path length of the near-infrared light to be connected to the first transmission part 44, which switches a position of the transmitter 40 to the light emission part 18 by sliding displacement of the structure for calibration 10.

Description

  The present invention relates to a calibration structure used for calibrating a blood component measuring apparatus for measuring a blood component in a living body with transmitted light, and to a calibration method thereof.

  It is recommended that diabetic patients routinely measure their own blood glucose fluctuations. For example, patients themselves have conventionally punctured their fingers to collect blood and use a measuring device to measure blood sugar levels. Measuring was done. However, since the measurement method described above imposes a great burden on the patient, in recent years, a non-invasive technique capable of measuring a blood component contained in blood by irradiating the patient with near infrared light has been used. An apparatus for measuring blood components has been developed.

  In this measurement method using the blood component measurement device, for example, glucose contained in blood absorbs a part of near-infrared light and is close to a part of a patient's body (for example, a finger). The blood glucose level (glucose concentration) is calculated by receiving near-infrared light transmitted through the body by irradiating infrared light and measuring the transmittance or absorbance. Further, when measuring this blood glucose level, it is difficult to determine whether the measured transmittance or absorbance is the glucose concentration in blood or the glucose concentration contained in body tissue. Is used to calculate the glucose concentration of blood based on the amount of glucose that periodically changes (see, for example, Patent Document 1).

  On the other hand, since the blood component measuring apparatus as described above requires measurement accuracy, calibration work is performed in order to reduce the measurement error. This calibration work is performed, for example, at the time of factory shipment of the apparatus or during regular maintenance and before blood glucose level measurement, and is performed using a predetermined calibration body. The calibration body transmits near infrared light and is filled with an aqueous solution containing a predetermined concentration of glucose inside. A blood component measurement device that transmits near-infrared light sequentially to a plurality of calibration bodies filled with aqueous glucose solutions of different concentrations and creates a calibration curve from the signal intensity obtained based on the transmittance or absorbance. In the database. By calculating the blood glucose level based on this calibration curve, the accuracy is improved in measuring the blood glucose level (see, for example, Patent Document 2).

Japanese Patent No. 3903340 JP 2000-258344 A

  When calibrating the blood component measuring apparatus by the above-described method, after transmitting near infrared light to the first calibration body, performing the work of transmitting the near infrared light by replacing with the next calibration body; Become. However, variations in the material and shape of the container, the concentration of blood components in the calibration liquid filled in the container, the temperature, the content of impurities, etc., and changes in the environment of the measuring device due to the exchange of calibration bodies, etc., exist among multiple calibration bodies. In this case, there is a concern that an error may occur in the signal intensity based on the transmittance or the absorbance when the near infrared light is transmitted. As a result, there arises a problem that the blood component concentration cannot be calculated with high accuracy based on the calibration curve obtained from the signal intensity.

  The present invention has been made in consideration of the above-described problems, and is a calibration structure used in a blood component measurement device that can further reduce measurement errors in the blood component measurement device and improve measurement accuracy. An object is to provide a body and a calibration method thereof.

In order to achieve the above-mentioned object, the present invention is used in a blood component measuring apparatus for measuring blood components by transmitting infrared light through the body, and a calibration structure for calibrating the blood component measuring apparatus. In the body,
A transmissive body that is filled with a calibration solution containing the blood component at a predetermined concentration and transmits the infrared light;
A moving means for moving the transmission body on an optical path between the light emitting unit and the light receiving unit between a light emitting unit emitting the infrared light and a light receiving unit receiving the infrared light;
Have
The transmissive body includes at least two or more transmissive portions having different optical path lengths in the transmissive body of the infrared light, or a transmissive portion in which the optical path length continuously changes, and the transmissive portion is the moving The optical path length is different along the direction.

  Thereby, the transmission part can be reliably and easily arranged between the light emitting part and the light receiving part by the moving means, and the transmission body is integrally formed with at least two transmission parts. Therefore, compared with the prior art in which calibration work is performed using a plurality of separate transmissive bodies, the material and shape of the transmissive body, the concentration of blood components contained in advance, the exchange of the calibrated body, etc. Variations can be avoided. As a result, it is possible to create a highly accurate calibration curve based on the transmission spectrum obtained by the transmission part, and by measuring the blood component using the calibration curve, the measurement error of the blood component can be further reduced. This can be further reduced and the measurement accuracy can be improved.

  In addition, a light scatterer is provided on the light path of the transmission body on at least one of the incident side of infrared light and the emission side transmitted through the transmission body, so that when actually measuring blood components of the body It is possible to reproduce the scattering in the living tissue around the blood vessel, and more accurate calibration can be performed.

  Furthermore, the moving means is provided with a positioning mechanism that positions the transmitting part at a position facing the light emitting part, so that at least two or more transmitting parts are reliably and simply arranged at positions facing the light emitting part, respectively. It becomes possible to perform a calibration operation of the component measuring apparatus.

  Furthermore, by providing a circulation path through which the calibration liquid circulates and a pump for causing the calibration liquid to flow, the solution is made to flow using a blood cell component of blood and a solution containing scattering particles imitating the blood cell component. Therefore, the calibration can be performed in a state closer to the natural state of the blood.

Further, the present invention is a method for performing calibration using a calibration structure for a blood component measuring apparatus that measures blood components by transmitting infrared light to an affected area,
In the calibration structure, at least one of at least two transmission parts having different optical path lengths of infrared light is disposed between the light emitting part that emits the infrared light and the light receiving part that receives the infrared light. And transmitting the infrared light to the transmission part to obtain a transmission spectrum;
The calibration structure is moved with respect to the blood component measuring device, and another transmissive part having a different optical path length is positioned between the light emitting part and the light receiving part, and the infrared light is transmitted to the other transmissive part. A transmission spectrum to obtain a transmission spectrum;
Calculating a signal intensity by differential analysis from the obtained at least two or more transmission spectra, and obtaining a calibration curve based on the signal intensity;
It is characterized by having.

  According to the present invention, the following effects can be obtained.

  That is, the transmissive body includes at least two transmissive portions having different optical path lengths, or a transmissive portion in which the optical path length continuously changes, and the transmissive portion transmits infrared light via a moving means. By enabling movement between the light emitting unit that emits light and the light receiving unit that receives the infrared light, the transmitting unit can be reliably and easily arranged on the optical path from the light emitting unit to the light receiving unit by the moving means. In addition, since at least two or more transmission parts are integrally formed in the transmission body, the transmission body can be compared with the prior art in which calibration work is performed using a plurality of transmission bodies that are separate from each other. Variations in measurement results due to the material and shape, the concentration of the predetermined blood component, the exchange of the calibration body, and the like can be avoided. As a result, it is possible to create a highly accurate calibration curve based on the transmission spectrum obtained by the transmission part, and by measuring the blood component using the calibration curve, the measurement error of the blood component can be further reduced. This can be further reduced and the measurement accuracy can be improved.

1 is a schematic configuration diagram of a blood component measurement device to which a calibration structure according to a first embodiment of the present invention is applied. It is a partial cross section side view of the blood component measuring device of FIG. It is an external appearance perspective view of the flow cell which comprises the structure for a calibration. In the blood component measuring device shown in FIG. 1, it is a schematic block diagram which shows the case where the structure for a calibration is moved to the base end side. It is a graph which shows the calibration curve based on the relationship between the signal intensity of the near infrared light obtained using the structure for calibration, and the density | concentration of a calibration liquid. It is a graph which shows the calibration curve based on the relationship between the signal intensity | strength obtained using the several calibration liquid which has a different density | concentration, and the density | concentration of this calibration liquid. It is an external appearance perspective view of the structure for a calibration which concerns on the 2nd Embodiment of this invention. 8A is a longitudinal sectional view of the flow cell shown in FIG. 7, FIG. 8B is a transverse sectional view of the flow cell shown in FIG. 8A, and FIG. 8C shows a transverse sectional view of the flow cell according to the modification. It is an external appearance perspective view of the structure for a calibration which concerns on the 3rd Embodiment of this invention. FIG. 10 is a top view of the calibration structure shown in FIG. 9. FIG. 10 is an external perspective view showing a state in which the calibration structure shown in FIG. 9 is moved along the guide groove with respect to the light emitting unit and the light receiving unit.

  Preferred embodiments of a calibration structure and a calibration method for calibrating a blood component measurement apparatus according to the present invention will be described below in detail with reference to the accompanying drawings.

  First, the blood component measuring apparatus 12 that is calibrated by the calibration structure 10 will be briefly described with reference to FIGS. 1 and 2.

  This blood component measuring device 12 measures the glucose concentration in the blood non-invasively, and is provided on the base body 14 and an upper portion on the distal end side of the base body 14 as shown in FIGS. When measuring blood components, for example, a socket 16 into which a finger of a subject is inserted, a light emitting unit 18 provided inside the base body 14 and capable of emitting light toward the socket 16 side, And a light receiving unit 20 to which light emitted from the light emitting unit 18 and transmitted through the finger is incident. The blood component measuring device 12 is integrally controlled by a computer (not shown) including the light emitting unit 18 and the light receiving unit 20.

  In FIG. 1, the upper side of blood component measuring device 12 having socket 16 is referred to as the “tip” side (arrow A direction), and the lower side of blood component measuring device 12 is referred to as the “base end” side (arrow B direction). The same applies to the other drawings.

  The upper surface of the base body 14 is formed in a planar shape. For example, the base body 14 is formed so that a finger or the like can be moved along the upper surface toward the socket 16 (arrow A direction).

  For example, the socket 16 is formed in a cover shape having a space into which the tip of a finger can be inserted, and a light receiving unit 20 is provided so as to face the space and the upper surface of the base body 14. The light receiving unit 20 is made of a photodiode, for example.

  The light emitting unit 18 includes, for example, a halogen lamp provided with a spectroscope that extracts near infrared light, or an LED capable of emitting near infrared light, and is provided at a position facing the light receiving unit 20 in the base body 14. In other words, the light emitting unit 18 and the light receiving unit 20 are disposed to face each other in the vertical direction in the base body 14 and the socket 16 through the space of the socket 16. That is, in the blood component measurement device 12, light is emitted from the light emitting unit 18 provided below in the vertical upward direction and received by the light receiving unit 20 (see FIG. 2).

  In the blood component measuring device 12, after inserting a finger (for example, an index finger) into the socket 16, the operator presses a measurement button (not shown), whereby the near infrared light emitted from the light emitting unit 18 is The light passes through the artery, vein and other tissues in the finger and is received by the light receiving unit 20. The computer receives a signal from the light receiving unit 20 during a period corresponding to a pulse, and obtains a blood glucose level through spectrum analysis and difference analysis.

  Next, the calibration structure 10 according to the first embodiment used for calibrating the blood component measuring apparatus 12 described above will be described with reference to FIGS.

  As shown in FIGS. 1 to 3, the calibration structure 10 includes a main body 24 in which a light scatterer 22 is housed, and a part of the main body 24 provided in the main body 24 and filled with a calibration liquid 26. The flow cell 28, a reservoir tank 30 provided at the end of the flow cell 28 in which the calibration liquid 26 is stored, and a pump 32 that circulates the calibration liquid 26 along the flow cell 28. As the calibration liquid 26, for example, a glucose aqueous solution or a particle suspension containing scattering particles is used.

  The main body 24 is formed, for example, in the shape of an ellipse having a circular arc at the tip, imitating a finger, and is filled with agar or the like that is the light scatterer 22. That is, in the calibration structure 10, by providing the light scatterer 22 inside, the scattering generated in the living tissue around the blood vessel when near infrared light is transmitted through the finger of the subject is reproduced.

  In addition, two sets of first and second recesses 34 and 36 are spaced apart from each other at a predetermined interval along the axial direction (arrow A, B direction) of the main body 24 on the side surface along the width direction of the main body 24. Formed. The first and second recesses 34 and 36 are formed, for example, so as to be recessed in a triangular cross section. The first recess 34 is the base end side (in the direction of arrow B) of the main body 24, and the second recess 36 is the main body. 24, the calibration structure 10 is inserted into the socket 16, and when the calibration structure 10 is inserted into the socket 16, the socket 16 A convex portion 38 having a triangular cross section formed on the inner wall surface is engaged. As a result, the calibration structure 10 including the main body 24 is positioned and fixed with respect to the socket 16.

  That is, the first and second concave portions 34 and 36 and the convex portion 38 function as a positioning mechanism that positions the calibration structure 10 with respect to the blood component measuring device 12.

  The flow cell 28 includes, for example, a transparent body 40 made of a transparent glass or resin material capable of transmitting near-infrared light and formed in a hollow shape, and tubes 42 respectively connected to both ends of the transparent body 40. Thus, the inside of the transmission body 40 and the tube 42 communicate with each other, and the calibration liquid 26 is filled. The transmissive body 40 is formed in a rectangular cross section, and is joined to the first transmissive portion 44 formed in a wide shape along the width direction of the main body portion 24 and the end portion of the first transmissive portion 44, and the main body portion 24. And a second transmission portion 46 formed in a wide shape along a height direction orthogonal to the width direction (see FIG. 3).

  As shown in FIG. 3, the first and second transmission parts 44 and 46 are hollow and have a rectangular cross section and are formed in substantially the same shape, and are joined so that their end parts intersect with each other at a substantially right angle at the central part. At the same time, the first transmission portion 44 is disposed on the proximal end side (in the direction of arrow B) and the second transmission portion 46 is disposed on the front end side (in the direction of arrow A).

  In other words, the horizontal cross-sectional area of the first transmission part 44 and the vertical cross-sectional area of the second transmission part 46 as viewed along the axial direction (arrow A, B direction) of the tube 42 are formed to be the same. Has been. Here, since the first and second transmission parts 44 and 46 are formed so as to have the same volume, the flow velocity does not change when the calibration liquid 26 is circulated inside the transmission body 40. Is preferred.

  As shown in FIG. 1, the transmissive body 40 has the first transmissive portion 44 in the state where the first concave portion 34 of the main body portion 24 is engaged with the convex portion 38 of the blood component measuring device 12. In the state where the second recess 36 is engaged with the projection 38 as shown in FIG. 4, the second transmission unit 46 and the light receiving unit 18 receive the light. It is arranged at a position facing the portion 20.

  The tube 42 includes a first conduit 48 that connects between the first transmission part 44 and the reservoir tank 30 in the transmission body 40, and a second connection that connects the second transmission part 46 and the reservoir tank 30 in the transmission body 40. The first pipe 48 extends from the first transmission part 44 toward the base end side (in the direction of arrow B) of the main body part 24, while the second pipe 50 is provided. Is extended from the second transmission part 46 toward the distal end side (arrow A direction) of the main body part 24 and then bent into a U shape and extends toward the proximal end side (arrow B direction). ing.

  A pump 32 is provided in the middle of the first conduit 48 to cause the calibration liquid 26 in the reservoir tank 30 to flow to the permeate 40 through the first conduit 48 and again through the second conduit 50 to the reservoir. It is circulated to the tank 30. That is, the flow cell 28 and the reservoir tank 30 constitute a circulation path for the calibration liquid 26.

  The pump 32 is used, for example, to flow the calibration liquid so that contained particles do not settle when the particle suspension is used as the calibration liquid. If it is not necessary to flow, the pump 32 need not be provided.

  Further, as shown in FIGS. 1 and 4, for example, another reservoir tank 30a in which calibration solutions 26 of different concentrations are stored is provided, and a plurality of reservoir tanks 30 and 30a and a flow cell 28 are connected via switching means (not shown). It is also possible to selectively switch the connection state. In this case, in the single calibration structure 10, it is possible to supply the calibration liquid 26 having different concentrations to the flow cell 28 and perform the calibration operation of the blood component measuring device 12.

  Next, a calibration method of the blood component measurement device 12 will be described. Here, the glucose solution having the same concentration Q is used as the calibration liquid 26, and the calibration liquid 26 is filled in advance in the permeation body 40 and the tube 42 constituting the calibration structure 10, and is supplied via the pump 32. Always keep in circulation.

  First, the operator holds the calibration structure 10 in the preparation state, and inserts it into the socket 16 of the blood component measuring device 12 from the distal end side of the main body 24. Then, as shown in FIG. 1, by engaging the first concave portion 34 of the main body 24 with the convex portion 38 of the socket 16, the first transmission portion 44 constituting the transmission body 40 becomes a blood component. It is positioned and fixed at a position facing the light emitting unit 18 and the light receiving unit 20 of the measuring device 12.

  Next, when the operator presses a measurement button (not shown) of the blood component measuring device 12, the near infrared light emitted from the light emitting unit 18 is transmitted through the main body 24 and the first transmission in the calibration structure 10. The light is transmitted through the unit 44 and received by the light receiving unit 20. At this time, since the main body 24 has the light scatterer 22, near-infrared light is scattered and included in the calibration liquid 26 when the near-infrared light passes through the first transmission part 44. A part of the near-infrared light is absorbed by glucose molecules and then received by the light receiving unit 20. Specifically, a portion of near infrared light having a unique wavelength is absorbed by glucose molecules.

  Then, an output signal based on the intensity of transmitted light received by the light receiving unit 20 is output to a computer (not shown), and a transmission spectrum PA is created through spectrum analysis performed in the computer. Specifically, the computer calculates the absorbance from the intensity of the light emitted from the light emitting unit 18 to the calibration structure 10 and the intensity of the transmitted light based on the output signal from the light receiving unit 20, and the absorbance. Based on this, a transmission spectrum PA is created.

  Next, the operator pulls the calibration structure 10 away from the socket 16 of the blood component measuring device 12, that is, by pulling in the base end side (direction of arrow B) of the blood component measuring device 12. The convex portion 38 is detached from the concave portion 34 and engaged with the second concave portion 36 (see FIG. 4). As a result, as shown in FIG. 4, the second transmitting portion 46 of the calibration structure 10 is positioned at a position facing the light emitting portion 18 and the light receiving portion 20 of the blood component measuring device 12.

  When the operator presses the measurement button again, the near infrared light emitted from the light emitting unit 18 passes through the main body 24 and the second transmitting unit 46 of the calibration structure 10 and is received by the light receiving unit 20. The At this time, as shown in FIG. 3, the second transmission part 46 that transmits near-infrared light has an optical path length L2 (cross-sectional area) along the irradiation direction of the near-infrared light. Is formed larger than the optical path length L1 (cross-sectional area) (L2> L1), the distance of the near-infrared light passing through the calibration liquid 26 becomes longer.

  As a result, in the second transmission unit 46, light absorbed by the calibration liquid 26 is increased as compared with the case where near infrared light is transmitted through the first transmission unit 44, and accordingly, the light reception unit 20 receives light. The near-infrared light emitted will be reduced. That is, when the near-infrared light is transmitted through the calibration structure 10, the absorbance when transmitted through the second transmission unit 46 is larger than the absorbance when transmitted through the first transmission unit 44.

  That is, the first transmission part 44 with a short optical path length L1 is for reproducing the transmission spectrum of the body when the blood vessel contracts due to pulsation and the blood volume is reduced, while the first transmission part 44 with a long optical path length L2 is used. The 2 transmission part 46 is provided in order to reproduce the transmission spectrum of the body when the blood vessel is expanded by pulsation and the blood volume is increased.

  Then, an output signal based on the intensity of the transmitted light received by the light receiving unit 20 is output again to a computer (not shown). The computer performs spectrum analysis and creates a transmission spectrum PB based on the absorbance.

  Finally, differential analysis is performed based on the transmission spectra PA and PB obtained when the first and second transmission parts 44 and 46 in the calibration structure 10 are transmitted, and the signal intensity S in the calibration liquid 26 is calculated. By doing so, a linear calibration curve K based on the relationship between the signal intensity S and the concentration Q of the calibration liquid 26 as shown in FIG. 5 is obtained.

  And in the blood component measuring device 12, this calibration curve K is preserve | saved as a database, A highly accurate measurement can be performed by referring when measuring a blood glucose level.

  In the above description, the case where the blood component measuring device 12 is calibrated using a single calibration solution 26 having a predetermined concentration Q has been described. For example, as shown in FIGS. A plurality of reservoir tanks are provided in the calibration structure 10, and calibration liquids 26 having different concentrations Q and Q1 to Q3 are sequentially sent to the flow cell 28 to obtain signal intensities S and S1 to S3 in the respective calibration liquids 26. Also good. In this case, as shown in FIG. 6, it is possible to create a calibration curve K1 with higher accuracy from the relationship between the signal strengths S and S1 to S3 and the concentrations Q and Q1 to Q3 of the calibration liquid 26. As a result, the blood component measurement device 12 can improve the measurement accuracy of the blood glucose level using the calibration curve K1 created with higher accuracy.

  As described above, in the first embodiment, in the calibration structure 10 that calibrates the blood component measurement device 12, the flow cell 28 filled with the calibration liquid 26 has different optical path lengths L1 and L2. The first transmission section 44 is provided by sliding and displacing the calibration structure 10 toward the distal end side or the proximal end side with respect to the blood component measurement device 12. Alternatively, either one of the second transmission parts 46 is surely positioned at a position facing the light emitting part 18 that irradiates near infrared light and the light receiving part 20 that receives the near infrared light transmitted through the calibration structure 10. And it can arrange easily.

  As described above, since the first and second transmission portions 44 and 46 are integrally formed and the same calibration liquid 26 is filled in the transmission body 40, the transmission body 40 is replaced with the blood component measurement device. 12 is slid to perform the calibration work, thereby avoiding variations in the material of the transmissive body 40, the concentration Q of the calibration liquid 26, the temperature, the content of impurities, and the like. There is no difference between the transmission spectrum PA obtained in step 1 and the transmission spectrum PB obtained in the second transmission section 46 due to variations.

  As a result, calibration curves K and K1 are created from the signal intensities S based on the transmission spectra PA and PB obtained with high accuracy, and are stored and used as a database in the blood component measuring device 12, for example. When the blood glucose level of the subject is measured by the component measuring device 12, a highly accurate measurement result can be obtained. In other words, the measurement error of the blood sugar level in the blood component measuring device 12 can be further reduced.

  In addition, since the first and second transmission parts 44 and 46 are integrally formed, a simple operation of slidingly displacing the calibration structure 10 including the transmission body 40 with respect to the blood component measurement device 12, The calibration structure 10 can be continuously calibrated via the first and second transmission parts 44 and 46 having different optical path lengths L1 and L2 without detaching the calibration structure 10 from the blood component measurement device 12 each time. . As a result, it is possible to efficiently perform the calibration work of the blood component measuring device 12 as compared with the conventional calibration method.

  Next, a calibration structure 100 according to a second embodiment is shown in FIGS. The same components as those of the calibration structure 10 according to the first embodiment described above are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIGS. 7 and 8, the calibration structure 100 according to the second embodiment includes a transmission body 102 having a substantially rectangular cross section and tubes 104 connected to both ends of the transmission body 102. And a holder 108 for holding the flow cell 106 in a displaceable manner.

  The transmissive body 102 is made of, for example, a transparent glass or resin material capable of transmitting near-infrared light, and has a light emitting unit 18 and a light receiving unit in the blood component measuring apparatus 12 with a wide lower surface and upper surface via a holder 108. 20 so as to face each other.

  A first conduit 48 of the tube 104 is connected to one end of the transmission body 102, and a second conduit 50 of the tube 104 is connected to the other end, and the first and second conduits are connected. 48 and 50 communicate with the communication passage 110 penetrating along the longitudinal direction (arrow A, B direction) of the transmission body 102.

  The communication passage 110 is formed in a substantially rectangular horizontal cross section, and when the calibration structure 100 is installed in the blood component measurement device 12, as shown in FIG. 8A, the near-infrared light from the light emitting unit 18 is transmitted. While the width dimension orthogonal to the irradiation direction is formed substantially constant, as shown in FIG. 8B, the width dimension of the communication path 110 along the irradiation direction is the base end side (the direction of arrow B) of the flow cell 106. The first transmission part 112 formed in the first is the largest, and the second transmission part 114, the third transmission part 116, and the fourth transmission part 118 formed in order toward the distal end side (the direction of arrow A) of the flow cell 106 are stages. It is set so that it gradually becomes smaller.

  In other words, the communication passage 110 has the largest width dimension on the base end side (arrow B direction) to which the first pipe line 48 is connected, and conversely, the tip end side (arrow A) to which the second pipe line 50 is connected. Direction) is set to the smallest width dimension.

  Thereby, when irradiating and transmitting the near infrared light from the light emitting unit 18 to the transmission body 102, the optical path lengths L3 to L6 are different in the first to fourth transmission units 112, 114, 116, and 118, respectively. Become. Therefore, a plurality of transmission spectra can be obtained from the single transmission body 102 by transmitting the near infrared light to the first to fourth transmission parts 112, 114, 116, and 118.

  Further, a scale 120 is provided on the side surface of the transmissive body 102, and the scale 120 is engraved at equal intervals along the longitudinal direction of the transmissive body 102 (directions of arrows A and B). The scale 120 is provided so as to be visible when facing the opened window 122 when the flow cell 106 is attached to the holder 108.

  The holder 108 is formed in a hollow shape into which the flow cell 106 can be inserted, has a pair of openings 124 through which the flow cell 106 is inserted, and has a window on a side surface different from the side where the opening portion 124 is formed. The part 122 is open. An indicator 126 used for confirming the position of the scale 120 is provided at a substantially central portion of the window portion 122.

  The flow cell 106 is inserted into the inside through the opening 124 of the holder 108, and the tube 104 protrudes to the outside of the holder 108, and the holder 108 is provided on the lower surface and the upper surface of the holder 108. The light emitting unit 18 and the light receiving unit 20 are connected to the probe through the main body unit 128 including the light scatterer 22. That is, the light emitting unit 18 is disposed below the holder 108 and the flow cell 106, and the light receiving unit 20 is provided at a position above the light emitting unit 18 with the holder 108 and the flow cell 106 interposed therebetween.

  When the calibration structure 100 is mounted on the blood component measuring device 12, the indicator 126, the light emitting unit 18, and the light receiving unit 20 are provided in a straight line when viewed from the window 122 side of the holder 108.

  Next, when calibrating the blood component measurement device 12 using such a calibration structure 100, first, the operator slides the flow cell 106 with respect to the holder 108 to emit light from the first transmission part 112. It arrange | positions to the position between the part 18 and the light-receiving part 20. In this case, for example, the operator moves the flow cell 106 while using the scale 120 provided on the transmission body 102 of the flow cell 106 and the indicator 126 of the holder 108 as a guideline, and moves the first transmission unit 112 to the light emitting unit 18 and the light receiving unit. It arrange | positions to the position which faces the part 20. FIG.

  Next, the near infrared light irradiated from the light emitting unit 18 and transmitted through the first transmitting unit 112 is received by the light receiving unit 20 to create a transmission spectrum PA, and then the flow cell 106 is slid again to move the second transmitting unit 114. It arrange | positions in the position which faces the light emission part 18 and the light-receiving part 20. FIG. Then, the near infrared light irradiated from the light emitting unit 18 and transmitted through the second transmitting unit 114 is received by the light receiving unit 20 to create a transmission spectrum PB. In this way, the third and fourth transmission units 116 and 118 in the flow cell 106 are sequentially irradiated with near-infrared light from the light emitting unit 18 and transmitted, and the light receiving unit 20 receives and transmits the transmission spectra PC and PD. Will continue to create.

  In this case, since the first to fourth transmission parts 112, 114, 116, and 118 have different optical path lengths L3 to L6 when near infrared light is transmitted, the first transmission part having the maximum optical path length L3. Absorbance when transmitting through 112 is the highest, and the absorbance of the near-infrared light decreases stepwise toward the fourth transmission section 118 having the minimum optical path length L6.

  Finally, the signal intensity of the calibration liquid 26 is calculated from the obtained transmission spectra PA, PB, PC, PD by differential analysis, and a calibration curve K based on the signal intensity can be obtained.

  Thereby, the transmissive body 102 of the flow cell 106 constituting the calibration structure 100 can be stably slid along the holder 108, and the scale 120 of the transmissive body 102 is displaced as a guideline, whereby the optical path The first to fourth transmission parts 112, 114, 116, and 118 having different lengths can be reliably moved to positions facing the light emitting part 18 and the light receiving part 20.

  As a result, it is possible to reduce the measurement error of the blood sugar level by performing the calibration operation of the blood component measuring device 12 reliably and with high accuracy.

  Note that the communication path 110 in the transmission body 102 is not limited to the case where the width dimension (optical path length) differs in a stepped manner as in the first to fourth transmission parts 112, 114, 116, and 118 described above. For example, as in a flow cell 138 shown in FIG. 8C, a tapered communication path 142 that gradually decreases in width (optical path length L7) from one end to the other end of the transmission 140 may be used. In this case, it is possible to continuously change the optical path length L7 in the transmission body 140 by displacing the flow cell 106 by a minute amount using the scale 120 provided in the flow cell 138 and the indicator 126 of the holder 108. Become. As a result, it is possible to dramatically increase the number of transmission spectrum samples obtained with the single transmission body 140, and to improve the accuracy of the calibration curve K obtained accordingly. Therefore, the blood sugar level measurement error can be further reduced by performing the calibration operation of the blood component measuring device 12 with higher accuracy.

  Finally, a calibration structure 150 according to a third embodiment is shown in FIGS. The same components as those in the calibration structures 10 and 100 according to the first and second embodiments described above are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the calibration structure 150 according to the third embodiment, as shown in FIGS. 9 to 11, the light emitting unit 18 and the light receiving unit 20 are slidable with respect to the main body 152, and the flow cell is used. It is different from the calibration structures 10 and 100 according to the first and second embodiments in that 154 is formed in a tubular shape.

  The main body 152 is formed in a substantially cylindrical shape having the light scatterer 22 therein, and a flow cell 154 is provided along the axial direction thereof. The flow cell 154 has a tubular shape through which the calibration liquid 26 can circulate. The flow cell 154 is on one end side of the flow cell 154 and has a first transmission path (permeation section) 156 having a pipe diameter D1 and the other end side. And a second transmission path (transmission portion) 158 having a large pipe diameter D2 (see FIG. 10). The first and second permeation paths 156 and 158 are arranged substantially parallel to each other with a predetermined distance therebetween, and project from one end of the main body 152 to be connected to a reservoir tank 30 (not shown). The first and second transmission paths 156 and 158 protrude from the other end of the main body 152 and are connected by being bent into a U-shaped cross section in plan view. At this time, the pipe diameter of the flow cell 154 is formed so as to gradually increase from the first transmission path 156 toward the second transmission path 158.

  In addition, a set of guide grooves 160 are formed on the outer peripheral surface of the main body 152 at positions that are orthogonal to the axes of the first and second transmission paths 156 and 158 and face the first and second transmission paths 156 and 158. Is done. The guide groove 160 is disposed so as to sandwich the first and second transmission paths 156 and 158, and extends in a direction orthogonal to the first and second transmission paths 156 and 158.

  The light emitting unit 18 constituting the blood component measuring device 12 is inserted into one guide groove 160, and the light receiving unit 20 of the blood component measuring device 12 is inserted into the other guide groove 160, respectively. It is held so as to be slidable along 160. In this case, the light emitting unit 18 and the light receiving unit 20 are displaced along the guide groove 160 while maintaining positions facing each other.

  When calibrating the blood component measurement device 12 using such a calibration structure 150, an operator holds a probe (not shown) coupled to the light emitting unit 18 and the light receiving unit 20 and guides the groove 160. The light emitting unit 18 and the light receiving unit 20 are arranged at positions facing the first transmission path 156 of the flow cell 154. Then, after the near infrared light transmitted through the first transmission path 156 is received by the light receiving unit 20 and the transmission spectrum PA is created, the probe is held again and moved along the guide groove 160, and the light emitting unit 18 and The light receiving unit 20 is disposed at a position facing the second transmission path 158 of the flow cell 154.

  And the near-infrared light which permeate | transmitted the 2nd transmission path 158 is received by the light-receiving part 20, and the transmission spectrum PB is produced. Since the pipe diameter D2 of the second permeation path 158 is set larger than the pipe diameter D1 of the first permeation path 156, the absorbance by the calibration liquid 26 filled therein is increased. Then, the signal intensity of the calibration liquid 26 is calculated from the transmission spectra PA and PB by differential analysis, and a calibration curve based on the signal intensity can be obtained. In the present embodiment, the light emitting unit 18 and the light receiving unit 20 are slid with respect to the main body 152. However, the main body 152 may be slid.

  Thereby, the configuration of the calibration structure 150 can be simplified to reduce the manufacturing cost, and the blood component measuring device 12 can be calibrated reliably and with high accuracy to reduce the blood sugar level measurement error. .

  The calibration structure and the calibration method for calibrating the blood component measurement apparatus according to the present invention are not limited to the above-described embodiments, and various configurations can be adopted without departing from the gist of the present invention. Of course.

DESCRIPTION OF SYMBOLS 10, 100, 150 ... Calibration structure 12 ... Blood component measuring device 16 ... Socket 18 ... Light-emitting part 20 ... Light-receiving part 22 ... Light-scattering body 24, 128, 152 ... Main-body part 26 ... Calibration liquid 28, 106, 138, 154 ... Flow cell 30, 30a ... Reservoir tank 32 ... Pump 40, 102, 140 ... Permeator 42, 104 ... Tube 44, 112 ... First permeation part 46, 114 ... Second permeation part 48 ... First conduit 50 ... First 2 pipes 108 ... holder 110 ... communication path 116 ... third transmission part 118 ... fourth transmission part 120 ... scale 126 ... indicator 156 ... first transmission path 158 ... second transmission path 160 ... guide groove

Claims (5)

In a structure for calibration used to calibrate the blood component measurement device, used in a blood component measurement device that measures the blood component by transmitting infrared light through the body,
A transmissive body that is filled with a calibration solution containing the blood component at a predetermined concentration and transmits the infrared light;
A moving means for moving the transmission body on an optical path between the light emitting unit and the light receiving unit between a light emitting unit emitting the infrared light and a light receiving unit receiving the infrared light;
Have
The transmissive body includes at least two or more transmissive portions having different optical path lengths in the transmissive body of the infrared light, or a transmissive portion in which the optical path length continuously changes, and the transmissive portion is the moving A calibration structure used in a blood component measurement device, wherein the optical path length is different along a direction. The calibration structure according to claim 1,
A calibration used for a blood component measuring apparatus, characterized in that a light scatterer is provided on at least one of the incident side of the infrared light and the emission side transmitted through the transmissive body on the optical path of the transmissive body. Structure. The calibration structure according to claim 1 or 2,
A calibration structure for use in a blood component measuring apparatus, wherein the moving means includes a positioning mechanism that positions the transmitting portion at a position facing the light emitting portion. The calibration structure according to any one of claims 1 to 3,
A calibration structure for use in a blood component measurement apparatus, comprising: a circulation path through which the calibration liquid circulates; and a pump for flowing the calibration liquid. A calibration method for calibrating a blood component measuring device that transmits infrared light through an affected area and measures a blood component using a calibration structure,
In the calibration structure, at least one of at least two transmission parts having different optical path lengths of infrared light is disposed between the light emitting part that emits the infrared light and the light receiving part that receives the infrared light. And transmitting the infrared light to the transmission part to obtain a transmission spectrum;
The calibration structure is moved with respect to the blood component measuring device, and another transmissive part having a different optical path length is positioned between the light emitting part and the light receiving part, and the infrared light is transmitted to the other transmissive part. A transmission spectrum to obtain a transmission spectrum;
Calculating a signal intensity by differential analysis from the obtained at least two or more transmission spectra, and obtaining a calibration curve based on the signal intensity;
A method for calibrating a blood component measuring apparatus, comprising:

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