Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B5/00—Measuring for diagnostic purposes; Identification of persons
  • A61B5/145—Measuring characteristics of blood in vivo, e.g. gas concentration or pH-value ; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid or cerebral tissue
  • A61B5/1455—Measuring characteristics of blood in vivo, e.g. gas concentration or pH-value ; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid or cerebral tissue using optical sensors, e.g. spectral photometrical oximeters
  • A61B5/14558—Measuring characteristics of blood in vivo, e.g. gas concentration or pH-value ; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid or cerebral tissue using optical sensors, e.g. spectral photometrical oximeters by polarisation
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B5/00—Measuring for diagnostic purposes; Identification of persons
  • A61B5/0059—Measuring for diagnostic purposes; Identification of persons using light, e.g. diagnosis by transillumination, diascopy, fluorescence
  • A61B5/0082—Measuring for diagnostic purposes; Identification of persons using light, e.g. diagnosis by transillumination, diascopy, fluorescence adapted for particular medical purposes
  • A61B5/0088—Measuring for diagnostic purposes; Identification of persons using light, e.g. diagnosis by transillumination, diascopy, fluorescence adapted for particular medical purposes for oral or dental tissue
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B5/00—Measuring for diagnostic purposes; Identification of persons
  • A61B5/41—Detecting, measuring or recording for evaluating the immune or lymphatic systems
  • A61B5/411—Detecting or monitoring allergy or intolerance reactions to an allergenic agent or substance
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
  • G01J4/00—Measuring polarisation of light
  • G01J4/04—Polarimeters using electric detection means
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
  • G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
  • G01N21/21—Polarisation-affecting properties
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
  • G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
  • G01N21/21—Polarisation-affecting properties
  • G01N21/211—Ellipsometry
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B5/00—Measuring for diagnostic purposes; Identification of persons
  • A61B5/0002—Remote monitoring of patients using telemetry, e.g. transmission of vital signals via a communication network
  • A61B5/0031—Implanted circuitry

Definitions

• the present invention uses an optically controllable optical rotation control element to measure the concentration of an optical rotation substance in a solution in which a substance having optical rotation is dissolved by a purely electronic control mechanism without using a mechanical movable mechanism. It is about technology. Ideally, the sugar concentration in the blood inside the body is measured non-invasively, or the sugar concentration in urine is detected optically without contact, or a linearly polarized light emitting device embedded in the human body and a liquid crystal type The voltage and low power miniature optical rotation angle detection element performs stable and harmless sugar measurement for a long time, and realizes a safe measurement of sugar concentration in blood, and a system for concentration management and alarm.
• a sound or graphic display will sound an alarm, or as an emergency measure, automatically use insulin or sugar as a convenient treatment. It provides a social activity aid for people with diabetes who need blood sugar management in their daily lives. If non-invasive blood glucose monitoring is realized, socially active bodies without blood sampling injections will be possible, especially for those in the reserve group of potential diabetic patients who are close to 10% of the population, and are ideal as health aids. And useful equipment. Conventional technology
• Non-invasive blood sugar to measure sugar concentration in human blood without blood collection The purpose is to realize a minute monitor device. Therefore, the sugar concentration must be calculated by measuring the light transmittance of the human body using a mechanism without moving parts.
• the blood bran content can be measured by clock control, and the results can be fed to the patient. If it is presumed that the patient's sugar supplement or insulin administration is not in time, as a remedy, the mechanism for automatic administration of the above drug in a safe range is connected to the blood glucose automatic measurement mechanism, and Accidents can be prevented before they occur.
• Such a device facilitates the social activities of diabetics or those in the reserve group. Even if there is some error in blood noninvasive sugar measurement, it is effective to be able to warn the person before an accident occurs due to deviation from the appropriate sugar content range of blood, if there is little actual harm. Unlike precise sugar content measuring devices for diagnostics and scientific analysis, there is a strong demand for a simple blood sugar content predictive measurement system that allows finite errors for social activity assistance applications. There is a social demand for a non-invasive and portable blood sugar concentration estimation device.
• the key point of the structure of the present invention is electro-optical rotation modulation by a twisted nematic liquid crystal element. In principle, this can be applied to linear polarizers and light receiving elements. More sugar content can be measured. Furthermore, the accuracy of optical rotation measurement is improved by combining an electro-optical phase modulation element composed of parallel alignment liquid crystal elements and converting elliptically polarized light into linearly polarized light and measuring the amount of light.
• the optically rotatory sample is irradiated with linearly polarized light, the elliptically polarized light from the sample is compensated for by an electro-optical rotation angle modulation device composed of a swist nematic liquid crystal element, and the elliptically polarized light is converted to linearly polarized light by an electro-optical phase modulation device.
• the extreme values of the detected light intensity are read, and the drive voltages of the twisted nematic liquid crystal element and the parallel-modulated phase modulation liquid crystal element are controlled by feedback, respectively, and the solution concentration of the rotatory substance is estimated and calculated from the electric control voltage. I do.
• the transmitted light intensity measurement and the optical rotation measurement were carried out in parallel or sequentially in a short time, and were normalized by the light intensity in the sugar range wavelength range. From the value of the optical rotation, for example, the sugar concentration in blood is estimated.
• a wavelength selection filter for the measurement light in combination, or perform time-series coding and modulation, and output the electrical signal output corresponding to the detection light to the filter corresponding to the code. It is also effective to measure the blood sugar level by reducing the effect of disturbance light by performing the measurement.
• a laser diode with linearly polarized light output or the output light of an element combining a light emitting diode and a linearly polarizing plate is used as a light source, and this is the angle of the optical rotation surface generated by optical rotation modulation when passing through the sample.
• the optical rotation angle of the specimen is inversely corrected by combining the twisted nematic liquid crystal element for controlling the optical rotation angle and the parallel alignment liquid crystal element for controlling the phase difference of each component of the birefringent light. Automatic control is performed so as to return to linearly polarized light, and the sugar concentration in blood is estimated from the value of the liquid crystal element drive voltage required for the optical rotation angle control.
• the linearly polarized light is rotated in the opposite direction to the rotation angle of the specimen by the rotation angle control liquid crystal element in advance, and the polarization angle of the light passing through the specimen is obtained. Is applied to the optical rotation angle control liquid crystal element so that the angle returns to the original angle. In the case of elliptically polarized light, it is corrected by a phase modulation liquid crystal element and converted to linearly polarized light.
• FIG. 1 is a block diagram showing a configuration of a concentration measuring device according to a first embodiment of the present invention.
• FIG. 2 is a graph showing the relationship between the voltage applied to the liquid crystal optical rotation element and the output of the light detection element.
• FIG. 3 is a graph showing the relationship between the sugar concentration and the applied voltage.
• FIG. 4 is a block diagram showing a configuration of a concentration measuring device according to a second embodiment of the present invention.
• FIG. 5 is a block diagram showing a configuration of a concentration measuring device according to a third embodiment of the present invention.
• FIG. 6 is a block diagram illustrating a configuration of a concentration measuring device according to a fourth embodiment of the present invention.
• FIG. 7 is a block diagram illustrating a configuration of a concentration measuring device according to a fifth embodiment of the present invention.
• FIG. 8 is a block diagram illustrating a configuration of a concentration measuring device according to a sixth embodiment of the present invention.
• FIG. 9 is a block diagram showing a configuration of a concentration measuring device according to a seventh embodiment of the present invention.
• Fig. 1 OA is a diagram for explaining the operation of the concentration measuring device of the present invention.
• Fig. 10B is a diagram for explaining the operation of the concentration measuring device of the present invention.
• Fig. 11 is an eighth embodiment of the present invention. Configuration of concentration measuring device according to the embodiment FIG.
• FIG. 12 is a schematic diagram showing a configuration of a concentration measuring device according to a ninth embodiment of the present invention.
• FIG. 13 is a block diagram showing the configuration of the concentration measuring device according to the tenth embodiment of the present invention.
• FIG. 14 is a block diagram showing a configuration of the concentration measuring device according to the first embodiment of the present invention.
• FIG. 15 is a diagram showing an example of the optical rotation control characteristic of the liquid crystal optical rotation control element used in the concentration measuring device of the present invention.
• FIG. 16A is a diagram showing the first half of a flowchart showing a measurement procedure for measuring the sugar concentration in a solution using the concentration measurement device shown in FIG.
• FIG. 16B is a diagram showing the latter half of the flowchart showing the measurement procedure for measuring the sugar concentration in the solution using the concentration measurement device shown in FIG. Example
• FIG. 1 is a block diagram showing a configuration of a concentration measuring device according to a first embodiment of the present invention.
• reference numeral 1 denotes a light source that outputs linearly polarized light, and is composed of, for example, a laser diode or the like.
• Reference numeral 2 denotes a specimen whose concentration of the optical rotation substance in the solution is measured by the apparatus of the present invention. If the sample is blood and the rotatory substance is sugar, then dextrorotatory darcose will be the target of measurement.
• Reference numeral 3 denotes a liquid crystal element having optical rotation, which is composed of a twisted nematic liquid crystal.
• a left-handed twisted nematic liquid crystal element is used when the concentration measuring device of the present invention is used as an optical rotation compensation type device, and a right-handed twisted nematic liquid crystal is used when the concentration measurement device is used in an additional optical rotation type.
• An element is used.
• a linear polarizing plate 5 denotes a photodetector composed of a photodiode or a light receiving element, and 6 denotes a light intensity detection circuit.
• reference numeral 7 denotes a control circuit, which determines a voltage to be applied to the liquid crystal optical rotation element 3 based on a detection value of the light detection element 5.
• Reference numeral 8 denotes a power supply circuit that supplies a voltage required for the liquid crystal optical rotation element 3 and a voltage required for driving the light source 1 based on the output of the control circuit.
• Reference numeral 9 denotes a concentration calculation circuit that calculates the concentration of the optical rotation substance in the solution based on the control output of the control circuit 7.
• the reverse bias voltage may be supplied by the power supply circuit 8.
• the linearly polarized light emitted from the light source 1 rotates in the polarization plane while passing through the sample 2 and becomes elliptically polarized light. Therefore, when the twisted nematic liquid crystal element 3 having an optical rotation in the opposite direction to the light passing through the sample is arranged, the elliptically polarized light passing through the element 3 is modulated in a direction in which the optical rotation is restored.
• the sample 2 is pure water and a voltage of, for example, 10 V is applied to the twisted nematic liquid crystal element 3 (having no optical rotation)
• the direction of the polarization plane of the linear polarizer 4 is orthogonal to the polarization plane of the light source 1. With this setting, the polarized light from the light source reaches the polarizing plate 4 without being modulated by the sample, and does not pass through the polarizing plate 4. Therefore, the output of the photodetector 5 takes the lowest value.
• the polarizer is set at a position rotated 90 degrees. In this case, when the applied voltage of the 90 ° twisted nematic liquid crystal element is 0, the pure water sample is in the darkest state, and the applied voltage increases as the sugar content of the D-type glucose solution increases.
• the extinction state is not completely eliminated, which causes an error in the measurement of sugar content.
• FIG. 2 shows the measured data when the voltage applied to the twisted nematic liquid crystal element was changed every time and no alignment liquid crystal element for phase correction was used
• Fig. 3 shows the calibration curve derived therefrom.
• the horizontal axis represents the voltage (V) applied to the swist nematic liquid crystal element
• the vertical axis represents the light intensity detection circuit output (V).
• the horizontal axis represents the sugar concentration in weight%
• the vertical axis represents the liquid crystal drive voltage (V) that gives the minimum light intensity. From this graph, it is understood that the sugar content in the solution can be calculated by detecting the voltage applied to the liquid crystal optical rotation element 3 where the output of the light detection element 5 is minimum in the apparatus of FIG. .
• the concentration calculating circuit 9 in FIG. 1 calculates the concentration of the optical rotation substance in the solution from the voltage applied to the liquid crystal optical rotation element 3 obtained by the control circuit 7 based on, for example, previously obtained data as shown in FIG. Is a circuit for obtaining.
• FIG. 4 is a block diagram showing a configuration of a concentration device according to a second embodiment of the present invention.
• a light wavelength selection filter 10 is provided on the emission surface of the light source 1, and further, the light passes through the wavelength selection filter 10 between the polarizing plate 4 and the photodetector 5.
• a second wavelength selection filter 11 that transmits only light is provided.
• FIG. 5 is a block diagram showing a configuration of a concentration measuring device according to a third embodiment of the present invention.
• the control circuit 7 further includes a modulation circuit 71 for modulating the emission intensity of the light source 1 with a specific code or frequency, and a light intensity detection element 5.
• a modulation circuit 71 for modulating the emission intensity of the light source 1 with a specific code or frequency
• a light intensity detection element 5 for extracting the modulation signal contained in the electrical output signal
• FIG. 6 is a block diagram showing a configuration of a concentration measuring device according to a fourth embodiment of the present invention.
• a transmitter 12 and a receiver 13 are provided, and a light source 1, a liquid crystal rotation element 3, a light detection element 5, a light intensity detection circuit 6, a control circuit
• This configuration enables remote control of the sensor part consisting of 7 and the power supply circuit 8.
• This configuration is suitable when the concentration measuring device of the present invention is used while worn on the body or when it is implanted in the body. That is, the light source 1, the liquid crystal optical rotation element 3, the polarizing plate 4, the light detection element 5, the light intensity detection circuit 6, the control circuit 7, the power supply circuit 8 and the transmitter 12 of FIG.
• the output can be sent to a control and analysis device installed outside the body via the transmitter 12 and the receiver 13. This makes it possible to minimize the portion to be implanted in the body and reduce the burden on the body.
• the control circuit 7 can be installed outside the body.
• FIG. 7 is a functional block diagram for explaining the configuration of the fifth embodiment according to the present invention.
• 122 is a linearly polarized light source means.
• a light source light emitting diode and a linear polarizing plate 102 are combined.
• a laser diode that outputs linearly polarized light is used as the light source 101.
• the linear polarizing plate 102 can be omitted.
• 103 is a polarimetric sample
• 112 is an electro-optical rotation modulation means for optical rotation compensation of a polarimetric sample
• 124 is a linearly polarized light intensity test. It is an exit means.
• the specimen 103 involves light scattering or polarization disorder.
• the light transmittance changes as a function of time.
• the optical rotation compensating means is used to detect the elliptically polarized light that has been subjected to the optical rotation angle modulation and birefringence in the specimen at a high 3 (signal-to-noise ratio) using the light intensity detecting means 124.
• This is means for performing compensation modulation of the optical rotation angle and phase compensation modulation for converting elliptical polarization into linear polarization.
• a liquid crystal element having a twisted structure of liquid crystal molecular alignment called a twist structure is used.
• the optical rotation angle is rotated by a twist angle with respect to the incidence of the polarized light component that matches the substrate alignment direction.
• the rotation angle rotation component decreases, and the rotation angle changes. This is used to electrically adjust the angle of rotation.
• a liquid crystal element having a parallel alignment is used as the phase modulation element.
• the substrate orientation angle is set to about 45 degrees with respect to the main axis of elliptically polarized light, the phase difference between ordinary light and extraordinary light is adjusted by the voltage applied to the same element, and the incoming elliptically polarized light is linearly polarized. Change to
• a parallel-aligned liquid crystal element for adjusting birefringence phase difference which returns elliptically polarized light to linearly polarized light, is converted to linearly polarized light.
• the linearly polarized light intensity detecting means 124 is composed of a combination of a linearly polarized light plate 106 and a light intensity detecting element 107.
• the light incident on the photodetector 107 is light that has passed through the linear polarizer, and an output proportional to the intensity of the linearly polarized light is obtained by the photodetector 107 independent of the optical rotation.
• a photodetecting element a PN junction element made of a reverse-biased silicon semiconductor, a phototransistor element, a sulfided photoconductive element, or the like can be used.
• As the linear polarizing plate a commercially available 50% absorption type inexpensive linear polarizing plate can be used.
• a method of a null method for detecting leakage light of detection light at the time of compensation and minimizing the leakage light, and compensation In some cases, both a maximum value tracking type method in which the amount of incident light on the detection element is detected and a control for maximizing the amount is configured.
• the specimen 103 is, for example, a blood holding part of a human body using a part of a finger, an earlobe or an arm.
• the optical rotation control element 104 is a twist-type liquid crystal element for optical rotation control with a twist angle provided with a pair of transparent substrates with transparent electrodes that have been subjected to alignment processing at a low tilt angle close to the substrate parallel. is there.
• the twist angle is not necessarily 90 degrees, but can be used from the rotation of the specimen to about 360 degrees.
• the plane of polarization of the incident polarized light rotates by the twist angle. If the polarization plane angle of the incident light and the liquid crystal molecule orientation angle do not match, the light velocity differs between the coincident component and the orthogonal component.
• the applied voltage is much higher than the threshold of the liquid crystal element, the optical rotation is lost because the liquid crystal molecules of the liquid crystal element are arranged perpendicular to the substrate, and the optical rotation becomes zero.
• the applied voltage is near the threshold, the optical rotation and the ratio of elliptically polarized light change simultaneously according to the applied voltage.
• the parallel alignment liquid crystal element 105 a transparent electrode was formed on a transparent substrate, and two substrates subjected to alignment processing were arranged in opposing parallel with the alignment processing directions aligned, and a liquid crystal material was injected and sealed between them. Element. At an applied voltage of 0, there is a difference in the phase of the transmitted light between the parallel component and the orthogonal component of the directional molecules.When a high voltage above the threshold is applied between the transparent electrodes sandwiching the liquid crystal phase, the liquid crystal molecules are oriented perpendicular to the substrate Therefore, the phase difference becomes zero. When an RMS voltage near the threshold is applied, the degree of the phase difference changes depending on the applied RMS voltage.
• the optical rotation compensating element 104 and the phase control element 105 return the optical rotation to the original, and the ellipticity of the light that has passed through the specimen 103 and changed in optical rotation and became elliptically polarized
• the effective value voltage applied to each liquid crystal element is adjusted so as to return to the state of linear polarization before passing through 103.
• the linear polarizer 107 the polarization plane passing through the polarizer 102 and the optical rotation control element when no voltage is applied is orthogonal so that the amount of light passing through when the specimen 103 is removed is minimized. And adjust the rotation.
• the photocurrent of the photodetector 107 is converted to a voltage, and the optical rotation control element 104 and the phase control element 105 are set so that this value is minimized.
• the driving effective value voltage of the liquid crystal control element is controlled by negative feedback by driving the liquid crystal control element.
• the polarizers 102 and 106 are arranged so that the polarization plane directions thereof are aligned in parallel so that when the specimen 103 is removed, the output of the photodetector is maximized.
• the voltage applied to the liquid crystal phase modulation element and the liquid crystal rotation angle modulation element is adjusted so that the output current of the light detection element 107 at the time of measurement when the sample is sandwiched between the phase control element 105 and the optical rotation Write formula force s Mel for feedback controlling the effective voltage of each of the element drive for driving a degree control element (1) 0 4.
• the first method has the advantage that high-precision measurement can be performed when the amount of disturbance light is small
• the second method has the advantage that the signal voltage of the electric circuit can be controlled while being large when the light amount of the light source is small.
• the light detection signal voltage level when the light source light quantity is set to a small value L0 is stored in a sampling and holding circuit and is set as S0, and the light source light quantity is set as L1.
• the voltage level of the photodetection signal at the time of the increase is set to S1
• the signals of S1 and SO are connected to the two differential input terminals of the differential amplifier circuit, and the difference is detected and amplified. This method can reduce the influence of extraneous light.
• the detection signal component can be converted to AC by time modulation
• an AC amplifier circuit can be used, and the amplified signal passes through only the vicinity of the time modulation signal component.
• a lock-in amplifier amplification method can be used.
• FIG. 8 is a block diagram showing a configuration of a concentration measuring device according to a sixth embodiment of the present invention.
• 2 2 2 is a linearly polarized light source
• 2 0 1 is a light emitting element
• 2 0 2 is a linear polarizing plate
• 2 0 1 is a laser diode Can be omitted.
• Reference numeral 204 denotes an optical rotation control element, in which the polarization plane of the polarized light source and the liquid crystal molecule alignment direction of the optical rotation control element are made to coincide.
• the output of the optical rotation control element 204 is linearly polarized light, and the plane of polarization is rotated by a twist angle at an applied voltage of 0. When the applied voltage is increased, the rotation of the plane of polarization is reduced.
• the drive voltage of the optical rotation control element 204 is adjusted so that the optical rotation of the specimen 203 becomes equal to the rotation of the polarization plane of the optical rotation control element 204 with the opposite sign.
• the polarization plane of the light that has passed through both the optical rotation control element 204 and the specimen 203 is corrected so that it is in the direction that includes the same paper plane and optical axis as the polarization plane of the light source 222, but becomes elliptically polarized light. I have.
• Elliptical polarization can be adjusted by applying a drive voltage to the phase modulation element 205.
• the phase modulation element 205 is arranged so that the orientation direction is different from the light source polarization plane by 45 degrees.
• FIG. 9 is a block diagram showing a configuration of a concentration measuring device according to a seventh embodiment of the present invention.
• Reference numeral 3222 denotes a linearly polarized light source
• reference numeral 301 denotes a light emitting element
• reference numeral 302 denotes a linear polarizing plate, which can be omitted when the light source 301 is a laser diode.
• Reference numeral 304 denotes an optical rotation control element, in which the polarization plane of the polarized light source and the liquid crystal molecule alignment direction of the optical rotation control element are matched.
• the linearly polarized light becomes elliptically polarized light, and the optical rotation control element 304 and the optical rotation control element 304 are adjusted so that the result of passing through the specimen 303 is approximated to linearly polarized light.
• the phase control element 305 is controlled.
• the elliptically polarized light that has passed through both elements is approximated to linearly modulated light through the specimen 303, and rotation is detected.
• Reference numeral 306 denotes a linearly polarizing plate
• reference numeral 307 denotes a light detecting element
• reference numeral 324 denotes a linearly polarized light detecting means.
• the optical rotation of the specimen 303 is adjusted by the drive voltage of the optical rotation control element 304 so that it becomes equal to the rotation of the polarization plane of the optical rotation control element 304 with the opposite sign.
• the polarization plane of the light that has passed through both the optical rotation control element 304 and the specimen 303 is corrected so that it is in the direction including the same paper plane and optical axis as the polarization plane of the light source 322, but is elliptically polarized. .
• Elliptically polarized light can be adjusted to linearly polarized light by applying a drive voltage to the phase modulation element 305.
• Phase modulation element 3 In FIG. 1 OA and B, the polarization wavefront control of FIG. 7 and FIG. In FIG.
• the output light 408 of the linearly polarized light source passes through the linearly polarizing plate 401 and is incident on the specimen 402, and the output optical rotation control element 403 compensates for the angle of the polarization plane.
• the elliptically polarized light returns to the same direction as the source light 408, and the elliptically polarized light further returns to linearly polarized light by the birefringent phase difference modulator 404.
• the output light 428 of the linearly polarized light source passes through the linearly polarizing plate 421 and is incident on the specimen 423 after the angle of the polarization plane is pre-adjusted by the optical rotation control element 422.
• the compensated result returns to the polarized light of the same direction as the source light 428, and the elliptically polarized light is corrected to linearly polarized light by the birefringent phase difference modulator 424, passes through the linear polarizer 425, and is detected.
• the light intensity is detected by the element 4 2 6.
• the optical rotation angle of the specimen 203 is represented by 0 1, and the optical rotation angle of the compensating element ⁇ 2.
• ⁇ 1 (X) a ⁇ a is a constant.
• the optical rotation angle 0 (V) of the optical rotation compensating element is a function of the drive voltage el of the optical rotation control liquid crystal element 204.
• the output voltage V dt of the light detecting means 224 is set so that the rotation position of the polarizing plate is selected and the optical rotation characteristic of the sample becomes 0 and the amount of transmitted light becomes 0 in order to increase the control sensitivity. Therefore, the initial position of the rotation angle of the polarizing plate 206 is ( ⁇ 0 + 90 degrees).
• the photodetecting element 107 Has an electrical output of V dt> 0. Amplify V dt to create a voltage e 1 that drives the liquid crystal rotation control element 203 and apply negative feedback. e When the value of 1 is gradually increased, the rotation angle change
• ⁇ s ⁇ a ⁇ — b ⁇ e l ⁇
• the amount of attenuation of the light amount due to the passage of the sample is measured, and the optical rotation is divided by the amount of attenuation to reduce the effect of changes in the amount of blood in the measured part of the body. You can do it.
• FIG. 11 shows an embodiment of the structure of a control system for measuring the concentration of an optical rotation substance according to the present invention.
• the overall configuration consists of a linearly polarized light source 504 including a laser diode, a liquid crystal optical rotation control element 506, a liquid crystal phase modulation element 508, and a light detection means combining a linear polarizer and a photodetector.
• Oscillation circuit mechanism consisting of crystal oscillation circuit, etc.5.Drive control circuit mechanism 5 that modulates the output light of linearly polarized light source 504 based on the Cook signal of constant and accurate frequency created by 14 16 Created in step 6
• the light source 504 is driven via the path 502.
• the detection signal of the optical detection means 510 is analyzed by the detection circuit mechanism 518 which extracts the optical rotation information with the synchronized time step signal generated from the same oscillator 514, and the concentration of the optical rotation sample is calculated. I do.
• the light source 504 is frequency-modulated by setting a certain rule, and the detection circuit mechanism 518 extracts the detection signal with a narrow-band extraction filter having a light source modulation frequency corresponding to the frequency, and cuts off the frequency.
• the detection signal component can be extracted with high S / N.
• the synchronous detection method and the coded modulation / demodulation method are effective in measuring the concentration of optically polar substances while eliminating the effects of various electrical noise and optical noise encountered by the subject.
• the generation and use of a lock signal is also effective.
• FIG. 12 shows an example in which the sugar content detection device of the present invention is worn on the body.
• a mechanical member that clamps at a constant thickness is effective.
• the sample is sandwiched by using a panel with a mechanism such as a washing pinch, but a projection or a clamp member for dimensional restriction is provided on the panel side or the pinching side, and the pinching thickness is always kept almost constant.
• reference numeral 602 denotes a density measuring device sandwiched between ear tabs
• reference numeral 604 denotes a module in which a polarized light emitting element and a polarized light detecting element are integrated, and the opposite side of the sandwiching member has a mirror surface.
• Reference numeral 608 denotes a circuit module including a signal processing and power supply battery and a wireless transmitter, which is disposed in an earlobe-type concentration measuring device.
• 606 is an earlobe.
• Reference numeral 610 denotes a washing pinching member for holding the earlobe, and reference numeral 612 denotes a panel for generating pinching pressure.
• Earlobes have the advantage that blood circulation does not change much and is not disturbed when worn.
• a method of setting such wearing equipment on the abdomen or in the limb inside the kimono is adopted.
• measurement is performed intermittently at a fixed time interval or time under clock control, and the measured data is stored and read out as needed.
• FIG. 13 shows an example of a system configuration when the sugar content detection device of the present invention is worn on the body.
• the sensor part is integrated into a minimal mechanism equipped with a power supply, taking into account the wearability, and the collected detection information is transmitted to the main portable device by short-range wireless communication.
• the main portable device further stores information in the patient's biometric data puncture using a public wireless telephone line so that the physician can make a diagnosis and judgment.
• reference numeral 708 denotes a sensor module, which is, for example, a wireless detection module such as an earlobe pinch module, a bracelet module, or an abdomen module shown in FIG.
• Reference numeral 702 denotes a sample
• reference numeral 706 denotes an optical rotation substance concentration detecting element of the present invention
• reference numeral 704 denotes a built-in clock which is synchronized with a clock of the main portable device 712.
• 714 is a short-distance communication transmission path using low-frequency magnetic waves of less than 10 kHz or weak radio waves.
• Reference numeral 716 denotes a short-range receiver of the main portable sensing device
• 718 denotes a main body processing mechanism including a signal analysis processing unit and a wireless transmission / reception connection mechanism with a public wireless telephone line.
• 7 2 8 is a public wireless telephone line
• 7 2 4 is a hospital system having a patient tracking management judgment function.
• the hospital system has a hospital wireless base station function using a public wireless telephone line, can be connected to a large number of portable testing devices, and can track and monitor patients at the time of patient access and patients who are entrusted with management. .
• the communication base function can be left to the central office.
• the information transmitted via the circuit 728 is bidirectionally connected to the portable device via the cellular transceiver, and the patient data is stored in the library 726 of the physician's diagnostic mechanism 720. .
• biosensing is not limited to local targeted therapies, and is widely used for information analysis and comparative diagnosis. Contacting the system will increase your benefits.
• a mechanism that does not impose excessive functions or energy burden on the sensing module is possible.
• the non-movable concentration detection method of the present invention can be made ultra-small and ultra-low power, and is suitable for a wireless concentration detection device worn on the body or a blood glucose concentration detection implanted in the body. Measurement is performed by intermittent measurement or time control to reduce average power consumption.
• FIG. 14 shows a system configuration example when the sugar content detection device of the present invention is worn on the body.
• FIG. 14 shows a configuration example of an implantable blood sugar concentration detecting device.
• Reference numeral 802 denotes a specimen
• 808 denotes a detection device
• 806 denotes a sensor element
• 804 denotes a built-in clock
• 822 denotes a secondary battery
• 824 denotes a charging coil.
• the 8 4 4 is a sugar monitoring device installed outside the body.
• the device 844 is a charger / information exchange device and is installed outside the human body.
• Reference numeral 834 denotes a low-frequency magnetic wave generator having a frequency of 10 kHz or less, which sends electric energy to the sensor device 850 for implantation in the body.
• 8 3 6 is the energy source of the charging device, which is obtained from the battery or the commercial power supply.
• 8 3 8 is a data analysis / alarm device that analyzes the in-vivo data input via the transceiver 8 2 8 and issues an alarm when the data indicates an internal abnormality. Synchronize with the device clock. The alarm may be displayed by providing a display device, for example, or may be displayed by sound or vibration.
• Reference numeral 828 denotes a transceiver, which transmits information to the embedded device using weak electromagnetic waves and collects information from the embedded device.
• Reference numeral 814 denotes the short-range communication path.
• the implantable sensor device 850 can be used in a titanium metal case, a sapphire, and a quartz member, which does not react to allergic reactions of the body.
• the measurement of the sugar concentration is always performed inside the body, and the measurement result can be safely transmitted outside the body.
• an automatic injection mechanism 860 and spare tanks for insulin and sugar are prepared in this configuration, an automatic injection mechanism for emergencies will be completed.
• the automatic injection mechanism and the reserve tank for insulin and sugar are prepared outside the body, and the data analysis in the sugar monitoring device 844 is performed according to the in-vivo information from the implanted sensor device 85. 8 issues a warning to the patient via the transmitter / receiver 828 or drives the automatic injection mechanism 860 to perform automatic injection of insulin or sugar.
• the sugar monitoring device 844 may monitor the implanted sensor device 850 at regular intervals, and may issue an alarm if an abnormality occurs, or may drive an automatic injection mechanism.
• FIG. 15 shows an example of the characteristics of the optical rotation control element used in the present invention.
• the characteristics show that an AC pulse of 32 kHz is applied to a liquid crystal device having a 45-degree twist structure.
• the optical rotation is 45 degrees.
• the optical rotation angle monotonically decreases to about 2 V.
• FIG. 16 is a flowchart showing a measurement procedure for measuring the sugar concentration in a solution using the concentration measurement device shown in FIG. FIG. 16A shows the first half of the flowchart, and FIG. 16B shows the latter half. The procedure of the concentration measurement will be described below with reference to this figure.
• a laser diode which is a linearly polarized light source is arranged, and then a transparent container containing the liquid to be tested is arranged perpendicularly to the output light of the diode as viewed from the light emitting position.
• the angle of the linear polarization plane of the laser beam is assumed to be 0 degree.
• One ⁇ degree swiss tone The angle of the plane of polarization of the linear polarizer is arranged orthogonally to the alignment axis of the exit side of the liquid crystal device, and then the photodetector is arranged.
• the detection light is blocked when the voltage applied to the twisted nematic liquid crystal element is 0, and the output of the light detection circuit outputs a signal with a light intensity of 0 level. (The value of this 0-level signal is stored in the storage circuit as VL0.) In this state, the sample solution is placed in the sample container.
• the orientation of the optically rotating molecules in the solution has a random distribution, so that the molecules whose long axis of the optical rotation coincides with the direction of the linear polarization plane have sufficient optical rotation.
• molecules at angles perpendicular to the long axis do not exhibit optical rotation, while molecules at intermediate angles exhibit intermediate optical activity, and, on average, concentration-dependent +
• the concentration measurement is started in step S1 in FIG. At this time, initialize the memories of the measuring device. At the same time, the counter value n is set to 0.
• next step S2 the light emitting diode is turned on, and the initial values of the measurement system are checked and stored.
• the output value VL of the photometric circuit is measured and the initial value VL0 is stored.
• the photometric value VL is stored with the applied voltage VT as an address value.
• the polarization plane is rotated by 8 ° due to the optical rotation of the sample solution, and elliptically polarized light is also generated to leak light.
• the optical rotation component of 1a decreases, and the output light of the liquid crystal element becomes elliptically polarized light.
• the light component passing through the linear polarizing plate temporarily decreases with an increase in the applied voltage, and then increases due to the above-described effect.
• the voltage of the twisted nematic liquid crystal element at which the transmitted light takes a minimum value increases.
• a relatively easy method is to take advantage of the fact that the width of the drive voltage that increases in a staircase waveform is set to a constant value, take a moving average of the 21 adjacent LCD drive voltages, and measure the light intensity of the average value Smoothing processing is performed so that the correction measurement value of the middle of the 21st is the first 1st correction measurement value, and the drive voltage that minimizes the correction light amount is the swivel drive voltage that gives the minimum value VLm of light.
• VTm is defined, and this voltage value VTm is applied to the twisted nematic liquid crystal element (step S6).
• phase modulation liquid crystal element When the phase modulation liquid crystal element is further arranged between the twisted nematic liquid crystal element and the polarizing plate on the liquid crystal element where the light transmission amount converges to a minimum value, and the phase difference is adjusted, the minimum value of the transmitted light becomes It is even lower.
• This phase compensation is performed in order to increase the accuracy of finding the minimum value of the light transmittance of the swist nematic liquid crystal.
• an apparatus that does not use a phase modulation liquid crystal element as in the first embodiment of the present invention shown in FIG. In the case of, step X below is omitted.
• step S7 the optical detection is performed when the driving voltage of the swiss nematic liquid crystal is VTm.
• the output circuit output voltage VL is stored.
• steps S8 to S10 the voltage VP applied to the phase modulation liquid crystal element is increased stepwise from 0 V to 6 V, and a voltage value VPm at which the output voltage VL takes a minimum value is detected. This voltage is applied to the phase modulation liquid crystal element.
• step S11 the number of measurements n, the voltage value VTm (n) obtained as described above, and the output voltage value VLm (n) are stored.
• step S12 convergence determination is performed. That is, in the (n_1) th and nth measurements, VLm (n) -one VLm (n-1) is obtained, and the measurement is repeated until this value converges within a predetermined fixed error ⁇ . . That is, while the data of the driving voltage VTm of the twisted nematic liquid crystal element which keeps the transmitted light minimum each time as the number of measurements ⁇ increases greatly returns to step S3 and repeats the measurement, the measurement result is within a certain error ⁇ The measurement is stopped when it becomes (Yes in step S12).
• step S 13 the applied voltage V Tm at that time is stored as “VT me”, and in step S 14, the solution sugar content corresponding to the value VTm e is obtained from the comparison table of the value V Tm e and the solution sugar concentration. Calculate the concentration. In step S15, the sugar concentration data G thus calculated is output.
• the measurement limit of the sugar concentration measurement is given by a noise signal added to the measured value ', a light intensity measurement error, a position fluctuation when the subject wears the sensor, and light noise outside the body.
• smoothing processing based on temporal averaging and averaging processing corresponding to the conditions near the measured values are performed.
• the liquid crystal drive voltage is changed from 0 V to 2 V through 200 steps with a staircase increase of 10 mV width, and the average of 11 data that are close to each other is averaged.
• the moving average method which replaces the average value of one piece of data with the sixth data in the center, the data from the sixth data to the 194th data will be smoothed by the above moving average.
• the individual moving average data is about 1/10 of the measurement error. Since we want to precisely grasp not the minimum value itself but the value of the applied voltage that gives the minimum value, performing the smoothing as described above is effective in eliminating the effect of sudden noise. Furthermore, the proximity data near the extremum of the smoothed 18 8 data is selected, a simple function such as a quadratic function is applied by the least square method, and this function is differentiated to give an extremum. It is possible to finely estimate the applied voltage. In this way, it is possible to easily calculate the minimum value based on the smoothed data.
• the above measurement procedure consists of installing a laser light-emitting element on a toilet bowl, placing a laser light reflection member on the toilet, and measuring the optical rotation of the reflected light with a twisted nematic liquid crystal element and a photodetector. Applicable to Washing toilets are washed each time and filled with a certain amount of water. Therefore, the level of urine can be estimated by measuring the water level, and the sugar concentration can be corrected.
• a liquid crystal device having a twisted structure has a rotatory power for the light of the principal axis component of the molecular orientation and can be used as an electronically controlled rotatory device. Since the light becomes elliptically polarized light with the applied voltage, the elliptically polarized light can be controlled to linearly polarized light by using a parallel alignment liquid crystal element for controlling a birefringence component phase difference.
• the alignment direction of the parallel alignment liquid crystal element and the main axis of elliptically polarized light are twisted by several tens of degrees, for example, 45 degrees, and the length of elliptically polarized light is determined by utilizing the difference between the main axis speed and the short axis speed of light passing through the parallel alignment liquid crystal element.
• linear polarization can be obtained.
• concentration of the optically active substance dissolved in the solvent can be relatively measured.
• the information on the polarization plane is different from the light intensity information, so it can be extracted.
• the detection of blood sugar content by electronic control of the liquid crystal optical rotation element can be reduced in volume and electric power, and is suitable for wearing or implanting on the body.
• an extremely portable saccharimeter By measuring the concentration of the optical rotatory solution by electronic control of the liquid crystal optical element, an extremely portable saccharimeter can be realized in an extremely small volume. It is low power and adapts to wearing or implanting. Since there are no moving parts, there is no debris, and stable operation for a long time is possible.

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