Automatic analysis device and automatic analysis method

Abstract

In an automatic analysis device, the influence of an interfering component on a measurement result can be appropriately suppressed. To this end, the automatic analysis device (1) is provided with a first light source (102) that irradiates light to a sample (44), a drive circuit (101) that supplies a first drive current (I3) whose frequency (f1-f2) is intermittently or continuously varied to the first light source (102), a light receiver (113) that outputs a light detection signal (IR) based on light transmitted through the sample (44), and a signal processing circuit (111) that demodulates the light detection signal (IR) in accordance with the frequency (f1-f2) of the first drive current (I3) and outputs a measurement signal (VL) based on a demodulation result.

Description

TECHNICAL FIELD

[0001] The present application relates to an automatic analysis device and an automatic analysis method. BACKGROUND

[0002] As background art in the technical field, Patent Literature 1 describes the following content: light from two light sources that differ from each other in emission wavelength and modulation frequency is irradiated to serum, and based on the intensity of transmitted light that has transmitted the serum, the amount of light absorption of the serum per wavelength is calculated. In addition, Patent Literature 2 describes the following content: a plurality of light sources are respectively modulated at different modulation frequencies, and only a desired signal component is detected by frequency separation.

[0003] PRIOR ART DOCUMENTS

[0004] PATENT LITERATURE

[0005] Patent Literature 1: Japanese Patent Application Publication No. 2008-26036

[0006] Patent Literature 2: Japanese Patent Application Publication No. 2006-329920 SUMMARY

[0007] PROBLEMS TO BE SOLVED BY THE INVENTION

[0008] However, in the above-described technology, there is a desire to appropriately suppress the influence of an interfering component on a measurement result.

[0009] Therefore, an object of the present application is to provide an automatic analysis device and an automatic analysis method that can appropriately suppress the influence of an interfering component on a measurement result.

[0010] MEANS FOR SOLVING THE PROBLEMS

[0011] To solve the above-described problems, the automatic analysis device of the present application is characterized by comprising: a first light source that irradiates light to a sample; a drive circuit that supplies a first drive current that discontinuously or continuously changes in frequency to the first light source; a light receiver that outputs a light detection signal based on light that has transmitted the sample; and a signal processing circuit that demodulates the light detection signal in accordance with the frequency of the first drive current, and outputs a measurement signal based on a demodulation result.

[0012] EFFECTS OF THE INVENTION

[0013] According to the present application, the influence of an interfering component on a measurement result can be appropriately suppressed. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 is a block diagram of an automatic analysis device of a first embodiment.

[0015] Figure 2 isFigure 1 a block diagram of the main part of the automatic analysis device.

[0016] Figure 3 is Figure 2 an example of a waveform chart of each part in the first comparative example.

[0017] Figure 4 is an example of a waveform chart of each part in the first comparative example.

[0018] Figure 5 a block diagram of the main part of the automatic analysis device of the second embodiment.

[0019] Figure 6 indicates a spectrum appearing in a photocurrent signal of the second embodiment.

[0020] Figure 7 indicates a spectrum appearing in a photocurrent signal of the second comparative example.

[0021] Figure 8 indicates a spectrum appearing in a photocurrent signal of the third comparative example. DETAILED DESCRIPTION

[0022] [PREMISE OF THE EMBODIMENT]

[0023] First, a case is assumed in which a light source is driven with a current having a fixed frequency, and the emitted light is made incident on a sample. In this case, if an interference having the same frequency as the driving frequency is mixed in, when the driving frequency component is separated from the measurement result, the interference component cannot be separated from the transmitted light component as an analysis object, and an error can be generated in the measurement result. In addition, when a plurality of light sources are driven with different frequencies as in the above-described Patent Literature 2, a signal corresponding to the difference in driving frequency becomes a beat signal, and it is possible that the signal is overlapped with a measurement value as noise. In addition, a signal generator of different frequencies, a frequency separation unit are required in the process of the light receiving signal, and there is a problem that the structure is complicated and high cost.

[0024] Therefore, in the embodiment described later, when an interference having the same frequency as the driving frequency is mixed in the output of the light receiver, the influence of the interference component is reduced. In addition, in the embodiment, when a plurality of light sources are driven, noise caused by a beat phenomenon is reduced without complicating the circuit structure.

[0025] [THE FIRST EMBODIMENT]

[0026] Figure 1 is a block diagram of the automatic analysis device 1 of the first embodiment.

[0027] In Figure 1In the present embodiment, the automatic analysis device 1 mainly includes a sample tray 10, a reagent tray 20, a reaction tray (incubator) 30, a light emitting section 40, a light receiving section 41, a light signal control section 42, and a computer 54.

[0028] The reaction tray 30 is formed in a substantially circular plate shape, and a plurality of (for example, about 100 to 200) reaction vessels 31 are arranged on the peripheral edge portion of the upper surface thereof. The reaction vessel 31 is a container formed in a substantially cuboid box shape of a light-transmissive material. The reaction vessel 31 is maintained at a predetermined temperature (for example, 37°C) by a thermostat 32.

[0029] In the illustrated example, a plurality of specimen containers 11 for housing biological samples such as blood or urine are arranged on the sample tray 10 in a circumferential direction in duplicate. In addition, a sample dispensing mechanism 16 is arranged in the vicinity of the sample tray 10. The sample dispensing mechanism 16 includes a movable arm 15 and a pipette nozzle 17 mounted to the movable arm 15.

[0030] With the above-described structure, when dispensing a sample, the pipette nozzle 17 is moved to a dispensing position by the movable arm 15, a predetermined amount of sample is sucked from a specimen container 11 located at a suction position of the sample tray 10, and the sample is discharged into a reaction vessel 31 located at a discharge position on the reaction tray 30.

[0031] A reagent refrigerator 22 formed in a substantially cylindrical shape is arranged in the reagent tray 20. A plurality of reagent bottles 21 are arranged in the reagent refrigerator 22 in the circumferential direction of the reagent tray 20. A label (not shown) showing reagent identification information such as a bar code is attached to each reagent bottle 21.

[0032] A reagent liquid corresponding to an analysis item that can be analyzed by the automatic analysis device 1 is housed in each reagent bottle 21. In addition, a bar code reading device 27 is arranged in the vicinity of the reagent tray 20. The bar code reading device 27 reads the bar code displayed on the outer wall of each reagent bottle 21 at the time of registering the reagent. The read reagent information is registered in the storage device 53 together with the position on the reagent tray 20.

[0033] In addition, a reagent dispensing mechanism 25 configured substantially the same as the sample dispensing mechanism 16 is arranged in the vicinity of the reagent tray 20. When dispensing a reagent, the reagent tray 20 arranges the reagent bottle 21 corresponding to the inspection item in the vicinity of the reagent dispensing mechanism 25. In addition, the reaction tray 30 arranges the corresponding reaction vessel 31 in the vicinity of the reagent dispensing mechanism 25. Then, the reagent dispensing mechanism 25 sucks the reagent liquid from the reagent bottle 21 by the pipette nozzle 25a and discharges it to the reaction vessel 31.

[0034] A stirring mechanism 36 is arranged in a position surrounded by the reaction disk 30, the reagent disk 20, and the reagent dispensing mechanism 25. The reaction liquid (sample) of the sample and the reagent accommodated in the reaction container 31 is stirred by the stirring mechanism 36 to promote the reaction. The light emitting section 40 is arranged near the center portion of the reaction disk 30, and the light receiving section 41 is arranged on the outer peripheral side of the reaction disk 30. The row of the reaction containers 31, which has completed the stirring, is moved in rotation so as to pass through the measurement light position sandwiched between the light emitting section 40 and the light receiving section 41.

[0035] For example, the reaction disk 30 is intermittently driven at a rotation angle of 45 degrees each time, and the reaction disk 30 rotates one turn in 9 seconds. The reaction liquid of the sample and the reagent in each reaction container 31 is irradiated with light from the light emitting section 40 each time the reaction liquid passes through the measurement light position by the rotation action of the reaction disk 30. The period during which one reaction container 31 passes through the measurement light position is, for example, about 10 to 30 msec. The transmitted light attenuated according to the absorbance of the reaction liquid is incident on the light receiving section 41 arranged in opposition. The light receiving section 41 separates the received light by wavelength, and supplies a photoelectric current signal corresponding to the intensity of each wavelength to the light signal control section 42.

[0036] Next, the control system and the signal processing system in the automatic analysis device 1 will be described. Figure 1 The computer 54 is connected to the sample dispensing control section 19, the reagent dispensing control section 29, and the light signal control section 42 via the interface 50. The computer 54 sends an instruction to the sample dispensing control section 19 to control the dispensing action of the sample. In addition, the computer 54 sends an instruction to the reagent dispensing control section 29 to control the dispensing action of the reagent.

[0037] The light signal control section 42 generates a measurement signal VL based on the photoelectric current signal of each wavelength measured by the light receiving section 41. Furthermore, the light signal control section 42 converts the measurement signal VL into numerical data, and supplies the numerical data to the computer 54 via the interface 50. A printer 56 for printing, a storage device 53 as a storage device, an external output medium (not shown), an input device 52 for inputting an operation instruction and the like, and a display device 51 for displaying a screen are connected to the interface 50.

[0038] The storage device 53 has, for example, a hard disk memory or an external memory (not shown). The storage device 53 stores information such as the password of each operator, the display level of each screen, the analysis parameters, the analysis item commissioning content, the calibration result, and the analysis result.

[0039] Next, the control system and the signal processing system in the automatic analysis device 1 will be described. Figure 1The automatic analysis device 1 performs sample analysis. Analysis parameters related to the items that the automatic analysis device 1 can analyze are pre-input via an input device 52 such as a keyboard, and these parameters are stored in the storage device 53. The operator uses the operation function screen of the display device 51 to select the examination items for each sample.

[0040] At this time, patient ID and other information are also input from the input device 52. In order to analyze the examination items indicated for each sample, the pipette nozzle 17 of the sample dispensing mechanism 16 dispenses a predetermined amount of sample from the sample container 11 to the reaction container 31 according to the analysis parameters.

[0041] The reaction vessel 31, having been dispensed with the sample, is moved by the rotation of the reaction plate 30 and stops at the reagent receiving position near the reagent dispensing mechanism 25. The pipette nozzle 25a of the reagent dispensing mechanism 25 dispenses a predetermined amount of reagent solution into the reaction vessel 31 according to the analytical parameters of the corresponding test item. Alternatively, the dispensing order of the sample and reagent can be reversed, with the reagent dispensing preceding the sample dispensing.

[0042] Then, the sample and reagent are stirred by the stirring mechanism 36 to mix them. When the reaction vessel 31 crosses the photometric position, the transmitted light of the reaction liquid is measured by the light receiving unit 41. The transmitted light obtained by photometry is converted into numerical data corresponding to the light intensity by the signal processing circuit and then input into the computer 54 via the interface 50.

[0043] Using the converted values, concentration data is calculated based on pre-determined calibration curves using the analytical method specified for each test item. The component concentration data, as the analytical results for each test item, is output to the printer 56 or the display screen 51. Before performing the above measurement actions, the operator sets various parameters required for the analysis and registers the sample via the operation screen on the display device 51. Furthermore, the operator confirms the analytical results after the measurement via the operation screen on the display device 51.

[0044] Figure 2 yes Figure 1 A block diagram of the main parts. Specifically... Figure 2 The details of the optical transmitter 40, optical receiver 41, and optical signal control unit 42 are shown.

[0045] exist Figure 2 In this light signal control unit 42, there is a light source driving circuit 101 (driving circuit) and a signal processing circuit 111. In addition, the light transmitting unit 40 has a light source 102 (first light source). The light source 102 is preferably a light source with good frequency response to the driving current, such as an LED.

[0046] The reaction container 31 has a pair of wall surfaces 31a parallel to the irradiation light L3 from the light source 40 and a pair of wall surfaces 31b orthogonal to the irradiation light L3. The hollow arrow 34 is the transport direction of the reaction disk 30 to the reaction container 31. In addition, a reaction solution 44 (a sample) after mixing a sample and a reagent is injected in the reaction container 31. In addition, the light receiving section 41 has a light splitter 112 that separates the received light by wavelength and a light receiver 113 that outputs a photoelectric current signal corresponding to the intensity of each wavelength.

[0047] Figure 3 is Figure 2 an example of a waveform chart of each part in

[0048] In Figure 3 , the horizontal axis of each chart is time t. In addition, the vertical axes of V, I, and L respectively indicate voltage, current, and intensity of light. Figure 3 Each waveform in Figure 2 is described below together with the content of

[0049] The light source driving circuit 101 has a direct current power supply 103 (a direct current component control section), an alternating current power supply 104 (an alternating current component control section), an adder 105, and a voltage / current converter 106. The direct current power supply 103 outputs a direct current voltage V1, and the alternating current power supply 104 outputs an alternating current voltage V2. Figure 3 The first paragraph of shows an example of the waveforms of the direct current voltage V1 and the alternating current voltage V2 and a driving current I3 supplied to the light source 102. Here, the frequency of the alternating current voltage V2 is continuously or intermittently varied in a range of f1 (the lowest frequency) to f2 (where f1 < f2) continuously or intermittently.

[0050] In addition, the frequencies f1 and f2 are preferably, for example, in a range of 1 kHz to 1 MHz, and more preferably in a range of 10 kHz to 100 kHz. In Figure 3 the example of the alternating current voltage V2 shown in , the amplitude is small around time t2. This is because the amplitude is reduced with the switching of the frequency of the alternating current voltage V2.

[0051] Figure 2 In , the adder 105 synthesizes the direct current voltage V1 and the alternating current voltage V2 and outputs a pulsating voltage V3 as a result thereof. The voltage / current converter 106 supplies a pulsating current, that is, a driving current I3 (a first driving current) of a size proportional to the pulsating voltage V3 to the light source 102. Thus, the light source 102 generates the irradiation light L3 whose intensity and frequency vary with time.

[0052] That is, the direct-current power supply 103 has a function of controlling the direct-current component of the drive current I3 by the direct-current voltage V1, and the alternating-current power supply 104 has a function of controlling the alternating-current component of the drive current I3 by the alternating-current voltage V2. The irradiation light L3 is irradiated to the reaction solution 44 as a measurement target when the irradiation light L3 crosses a light measurement position (not shown) of the reaction solution 44. Figure 3 The first and second paragraphs of FIG. 10 show examples of waveforms of the drive current I3 and the irradiation light L3. In the example shown, the waveforms of the drive current I3 and the irradiation light L3 are substantially the same.

[0053] In addition, in the second paragraph of FIG. 10, the waveform of the interference component VD is shown. Figure 3

[0054] In the example shown, the interference component VD is expressed in the dimension of voltage (V), but the interference component VD is generated in various dimensions and can affect the signals of each part of the automatic analysis device 1. For example, as examples of the interference component VD, there are interference caused by electric coupling of a substrate pattern or wiring of a commercial power supply, interference mixed into the automatic analysis device from other equipment, interference of a pulse signal for actuating a motor within the device, interference of a temperature control signal of a reagent refrigerator or a thermostat, interference accompanying periodic changes in inductive or capacitive coupling states along with the operation of each mechanism, changes in the amount of light generated along with vibration at the time of rotation of a disk, and the like.

[0055] Further, in the second paragraph of FIG. 10, the waveform of the interference component VD is shown. Figure 2 In the second paragraph of FIG. 10, the signal processing circuit 111 includes a current / voltage converter 114, a high-pass filter 115, an amplifier 116, a multiplier 117, a phase shifter 118, a low-pass filter 119, and an A / D converter 120.

[0056] The spectrometer 112 spectrally splits the light that has passed through the reaction solution 44 into components of a plurality of wavebands. The light receiver 113 converts the light of each waveband after the spectral splitting into a photocurrent signal IR (a light detection signal). Figure 3 The second paragraph of FIG. 11 shows an example of a waveform of the photocurrent signal IR. In addition, the light receiver 113 outputs the photocurrent signal IR in the number of wavebands, and in the second paragraph of FIG. 11, the waveform of the photocurrent signal IR corresponding to one waveband is shown. Figure 3 In the second paragraph of FIG. 11, with respect to the photocurrent signal IR and a signal generated in the subsequent stage, the signal corresponding to one waveband is shown. In addition, the waveform of an ideal photocurrent signal IRX is shown by a dashed line, overlapping the waveform of the photocurrent signal IR. Here, the ideal photocurrent signal IRX is a virtual photocurrent signal IR assuming that there is no interference component VD at all. In other words, the photocurrent signal IR actually observable is a signal in which the interference component VD is superimposed on the ideal photocurrent signal IRX.

[0057] Returning to Figure 2 ​The current-to-voltage converter 114 converts the photocurrent signal IR into a voltage signal. A high-pass filter 115 removes components in the voltage signal that are lower than a predetermined cutoff frequency ft, and outputs the result as an AC signal VH. Here, the cutoff frequency ft is set to a frequency lower than the lowest frequency (i.e., frequency f1) of the drive current I3.

[0058] Figure 3 The third section shows an example waveform of the AC signal VH. Overlapping with this, a dashed line represents the waveform of the ideal AC signal VHX assuming no interference component VD. Thus, the high-pass filter 115 removes components corresponding to the DC component of the drive current I3, offsets appearing in the photocurrent signal IR, offsets generated in the current / voltage converter 114, etc.

[0059] Return to Figure 2 Amplifier 116 amplifies the AC signal VH and outputs it as the AC signal VH'. Additionally, the light source drive circuit 101 supplies a synchronization signal V2S to the signal processing circuit 111. Figure 3 The third paragraph shows an example waveform of the synchronization signal V2S. In the example shown, the synchronization signal V2S has the same waveform as the AC voltage V2.

[0060] Return to Figure 2 Phaser 118 adjusts the phase of the synchronization signal V2S to match the phase of the AC signal VH', and outputs the result as the synchronization signal V2S'. Multiplier 117 multiplies the synchronization signal V2S' with the AC signal VH', and outputs the result as the multiplication signal VM. Alternatively, if the phase of the output signal of amplifier 116 is approximately the same as the phase of the synchronization signal V2S, phaser 118 can be omitted, and the synchronization signal V2S can be directly supplied to multiplier 117 as the synchronization signal V2S'.

[0061] exist Figure 3 The third section shows an example waveform of the multiplication signal VM. Overlapping with this, the waveform of the ideal multiplication signal VMX, assuming no interference component VD, is represented by a dashed line.

[0062] It can be considered that Figure 2 The process of multiplying the AC signal VH' and the synchronization signal V2S' in multiplier 117 involves pattern matching between the two. That is, it can be assumed that the multiplied signal VM is obtained by extracting the photocurrent component of the AC signal VH' that has a strong correlation with the synchronization signal V2S'. In fact, as... Figure 3 As shown in the example waveform of the multiplication signal VM, if two signals of the same frequency are multiplied, the result of the multiplication becomes a waveform close to a sine wave after squaring, with the frequency component at twice the frequency being more prominent.

[0063] This correlation strong photocurrent component is a photocurrent signal modulated according to the absorbance of the reaction solution 44. Therefore, the multiplication signal VM is approximately proportional to the result of squaring the photocurrent signal. Therefore, by measuring the amplitude intensity of the multiplication signal VM, the absorbance of the reaction solution 44 can be measured. Also, even if envelope detection is performed to draw the envelope of the maximum value of the multiplication signal VM, the level of the envelope detection result is measured, and the absorbance of the reaction solution 44 can be measured.

[0064] In Figure 2 , the low-pass filter 119 smoothes the multiplication signal VM and outputs it as a measurement signal VL. The A / D converter 120 converts the measurement signal VL into numerical data and supplies it to the computer 54 via the interface 50 (refer to Figure 1 ). Figure 3 The fourth paragraph of the above shows a waveform example of the measurement signal VL. When the low-pass filter 119 smoothes the multiplication signal VM, the frequency band of the interference component VD is almost removed. Therefore, the waveform of the illustrated measurement signal VL is approximately the same as the waveform of an ideal measurement signal (omitted from illustration) assuming that there is no interference component VD at all. In this way, the signal processing circuit 111 has a function of demodulating the photocurrent signal IR according to the frequency fl to f2 of the drive current I3 and outputting the measurement signal VL based on the demodulation result.

[0065] In the present embodiment, if the frequency of the drive current I3 is changed over time, a significant difference appears between the multiplication signal VM and the ideal multiplication signal VMX at the moment when the frequency of the drive current I3 coincides with the frequency of the interference component VD. However, during other periods, the influence of the interference component VD is dispersed, and therefore it is known that the influence of the interference component VD hardly appears in the multiplication signal VM.

[0066] Then, the multiplication signal VM thus changed from the frequency fl to the frequency f2 is supplied to the low-pass filter 119, and the multiplication signal VM including the interference component is integrated over time, whereby the influence of the interference component appearing instantaneously on the measurement signal VL can be reduced. Also, in the present embodiment, it is not necessary to investigate the frequency of the interference component VD in advance, and the influence of the interference component VD under various environments can be reduced with the same circuit structure.

[0067] Here, the cut-off frequency of the low-pass filter 119 is described. The cut-off frequency of the low-pass filter 119 can be determined according to the frequency of the drive current I3 and the rotation speed of the reaction disk 30 (refer to Figure 1 ). Incidentally, in the above, the wall surface 31a (refer to Figure 2When the photometer crosses the measurement position, square-wave noise is superimposed on the photocurrent signal IR. Therefore, it is preferable to set the cutoff frequency of the low-pass filter 119 to a frequency that can sufficiently suppress the influence of this square-wave noise from the measurement signal VL.

[0068] However, even when noise generated by the wall 31a is superimposed on the measurement signal VL, this noise can be removed by various methods. For example, consider setting up a detection circuit (not shown) to enter the photometric area, i.e., a pair of walls 31a (see reference 10000) at the photometric position. Figure 2 A predetermined trigger signal is output at a time point within the region between () and (). By feeding this trigger signal back to the multiplication signal VM, the smoothing responsiveness in the low-pass filter 119 can be improved. Alternatively, in the A / D converter 120, the same trigger signal can be used as a starting point for A / D conversion, and the measurement signal VL can be averaged through discrete data manipulation.

[0069] [First Comparative Example]

[0070] Next, the first comparative example will be explained.

[0071] The structure of the first comparative example is the same as the structure of the first embodiment described above. Figure 1 , Figure 2 They are the same, but the difference is that the frequency of the AC voltage V2 generated by AC power supply 104 is fixed.

[0072] Figure 4 These are examples of waveform diagrams for each part in the first comparative example. Figure 4 In, also with Figure 3 Similarly, the horizontal axis of each chart represents time t. Additionally, the vertical axes V, I, and L represent voltage, current, and light intensity, respectively.

[0073] exist Figure 4 In the first paragraph, the DC voltage V1 and Figure 3 The DC voltage shown is the same. Furthermore, the AC voltage V2C is the AC voltage V2 in this comparative example. The AC voltage V2C is the same as the DC voltage V2 in that it has a fixed frequency. Figure 3 The waveform of the AC voltage V2 shown is different. Furthermore, the drive current I3C is the same as the drive current I3C in this comparative example, and it remains consistent with the fixed frequency. Figure 3 The waveforms of the driving current I3 shown are different.

[0074] exist Figure 4 In the second paragraph, the illumination light L3C is the illumination light L3 in this comparative example. Additionally, the interfering component VD and... Figure 3The illustrated interference component is the same. However, the frequency of the interference component VD is set to coincide with the pulsation frequency of the irradiation light L3C in the present comparative example. Further, the photocurrent signal IRC is the photocurrent signal IR in the present comparative example, and is still the same in the point that the frequency is fixed. Figure 3 The illustrated photocurrent signal IR waveform is different. Further, the waveform of the ideal photocurrent signal IRCX assumed in the case where the interference component VD is completely absent is indicated by a broken line, superimposed on this.

[0075] In the third paragraph of FIG. 10, Figure 4 the AC signal VHC is the AC signal VH in the present comparative example, and is still the same in the point that the frequency is fixed. Figure 3 The illustrated AC signal VH waveform is different. Further, the synchronization signal V2SC is the synchronization signal V2S in the present comparative example. In the illustrated example, the synchronization signal V2S has the same waveform as the AC voltage V2.

[0076] Further, the multiplication signal VMC is the multiplication signal VM in the present comparative example, and is still the same in the point that the frequency is fixed. Figure 3 The illustrated multiplication signal VM waveform is different. Further, the waveforms of the ideal AC signal VHCX and the ideal multiplication signal VMCX assumed in the case where the interference component VD is completely absent are indicated by broken lines, superimposed on each of the graphs of the AC signal VHC and the multiplication signal VMC.

[0077] As described above, in the present comparative example, the frequency of the interference component VD coincides with the pulsation frequency of the irradiation light L3C. Therefore, the relationship of the AC signal VHC to the ideal AC signal VHCX is the same in each cycle of the AC signal VHC. For example, in the illustrated example, the amplitude of the AC signal VHC is larger than the amplitude of the ideal AC signal VHCX in any cycle. As a result, the maximum value in each cycle of the multiplication signal VMC is higher than the maximum value of the ideal multiplication signal VMCX in any cycle.

[0078] In the fourth paragraph of FIG. 10, Figure 4 the measurement signal VLC is the measurement signal VL in the present comparative example. Further, the waveform of the ideal measurement signal VLCX assumed in the case where the interference component VD is completely absent is indicated by a broken line, superimposed on the graph of the measurement signal VLC. According to the relationship of the multiplication signal VMC to the ideal multiplication signal VMCX in the third paragraph described above, a significant difference occurs in the measurement signal VLC with respect to the ideal measurement signal VLCX. This occurring difference becomes an error of the measurement signal VLC. Thus, in the first comparative example, there is a problem that a significant error occurs for the measurement signal VLC when the frequency of the interference component VD coincides with (or is close to) the pulsation frequency of the drive current I3C.

[0079] [Second Embodiment]

[0080] Figure 5 is a block diagram of main parts of the automatic analysis device 2 of the second embodiment. Further, in the following description, the same reference numerals are attached to the parts corresponding to the respective parts of the above-described first embodiment, and the description thereof is sometimes omitted.

[0081] The overall structure of the automatic analysis device 2 is the same as that of the automatic analysis device 1 (refer to Figure 1 ) of the above-described first embodiment. However, in the present embodiment, instead of the light source driving circuit 101 and the light transmitting section 40 in the first embodiment, a light source driving circuit 151 (driving circuit) and a light transmitting section 140 shown in Figure 5 are provided.

[0082] The light transmitting section 140 has, in addition to the above-described light source 102, another light source (second light source) 152. The light sources 102, 152 preferably use light sources having different wavelength distributions of radiated light. Thereby, it is possible to obtain measurement results in a wider band. Further, the light source driving circuit 151 has, in addition to the same constituent elements 103 to 106 as those of the light source driving circuit 101 (refer to Figure 2 ) of the first embodiment, a direct current power supply 153, a summer 155, and a voltage / current converter 156.

[0083] The direct current power supply 153 outputs a direct current voltage V21. The summer 155 synthesizes the direct current voltage V21 and the alternating current voltage V2, and outputs a pulsating voltage V23 as a result thereof. The voltage / current converter 156 supplies a pulsating current, that is, a driving current I23 (second driving current) having a magnitude proportional to the pulsating voltage V23, to the light source 152. Thereby, the light source 152, like the light source 102, generates irradiation light whose intensity and frequency vary with time. According to the above-described structure, the light sources 102, 152 both emit light in time variation at the same frequency based on the alternating current voltage V2.

[0084] Figure 6 represents the frequency spectrum SP1 appearing in the photocurrent signal IR of the second embodiment.

[0085] When the alternating current voltage V2 varies in the range of frequencies fl to f2, frequency components such as beat frequencies fbl, fb2 appear in the frequency spectrum SP1. Here, the beat frequencies fbl, fb2 are values of "fbl = f2 - fl, fb2 = fl + f2".

[0086] However, as shown in the figure, the beat frequencies fbl and fb2 are sufficiently apart from the frequencies fl and f2. Therefore, for example, when the cut-off frequency ft of the high-pass filter 115 is set as shown in the figure, it is possible to remove the component of the beat frequency fbl from the alternating current signal VH. Further, the component of the beat frequency fb2 is removed from the synchronous signal V2S (refer to Figure 5The frequency fl~f2 dependence of this component is low. Therefore, this component can be sufficiently reduced by pattern matching in the multiplier 117 and smoothing processing by the low-pass filter 119.

[0087] In the present embodiment, the light sources 102, 152 (refer to Figure 5 ) emit light in association with temporal changes in the same frequency. Therefore, in the photoelectric current signals of each of the transmitted lights that are emitted from the respective light sources 102, 152 and transmitted through the reaction solution 44, frequency difference components based on the beat phenomenon are difficult to occur. Also, the photoelectric current signals based on both of the transmitted lights exhibit temporal changes in the same frequency, and therefore a common high-pass filter 115, a multiplier 117, a low-pass filter 119, and the like can be used to obtain the measurement signal VL.

[0088] From the viewpoint of "matching the frequencies" of the drive currents supplied to the light sources 102, 152, for example, an AC power source of the same kind as the AC power source 104 is further added, and the AC voltages output from each of the AC power sources are supplied to the adders 105, 155, respectively. However, if a plurality of AC power sources of the same kind are applied, the following problem occurs: a slight frequency difference occurs due to variations in the manufacturing process, usage conditions, and the like. Therefore, if the common AC voltage V2 output from the one AC power source 104 is supplied to both of the adders 105, 155 as in the present embodiment, it is considered preferable in terms of being able to avoid such a problem. As described above, according to the present embodiment, a wide wavelength band of measurement results can be obtained using a plurality of light sources 102, 152, and the influence of the beat phenomenon can be sufficiently suppressed, and intensity measurement of light can be easily achieved.

[0089] [Second Comparative Example]

[0090] Next, the second comparative example will be described.

[0091] The structure of the second comparative example will be omitted from illustration, and in the second comparative example, the same light transmission section 140 (refer to Figure 5 ) as in the second embodiment is applied. Also, a drive current of a pulsating current whose pulsating frequency is fixed at fl is supplied to the light source 102. In addition, a drive current of a pulsating current whose pulsating frequency is fixed at f3 (where fl < f3) is supplied to the light source 152. The structure of the second comparative example other than the above is the same as the structure of the second embodiment (refer to Figure 1 , Figure 5 ).

[0092] Figure 7 A frequency spectrum SP2 that occurs in a photoelectric current signal IR of the second comparative example is shown.

[0093] Since the pulsation frequency of the driving current supplied to the light source 102 is f1 and the pulsation frequency of the driving current supplied to the light source 152 is f3, beat frequencies such as fb4 and fb5 are generated in the frequency spectrum SP2. Here, the beat frequencies fb4 and fb5 are values ​​of "fb4 = f3 - f1, fb5 = f1 + f3".

[0094] like Figure 7 As shown, beat frequencies fb4 and fb5 are sufficiently far from frequencies f1 and f3. Therefore, similar to the second embodiment described above, it is possible to remove the components of beat frequencies fb4 and fb5 from the AC signal VH or the multiplication signal VM. However, when the interference VD (refer to...) Figure 4 When the frequency of the second paragraph is the same as that of frequency f1 or f3, similar to the first comparative example above, the problem of errors being mixed into the measurement signal VL will occur.

[0095] [Third Comparative Example]

[0096] Next, the third comparative example will be explained.

[0097] The structure of the third comparative example is omitted from the illustration, but in the third comparative example, the same light transmitting unit 140 as in the second embodiment is used (see reference). Figure 5 Furthermore, similar to the second embodiment described above, a driving current with a pulsation frequency varying within the range of f1 to f2 is supplied to the light source 102. On the other hand, a driving current with a pulsation frequency varying within the range of f3 to f4 (where f1 < f2 < f3 < f4) is supplied to the light source 152. The structure of the third comparative example other than those described above is similar to the structure of the second embodiment (see...). Figure 1 , Figure 5 )same.

[0098] Figure 8 The spectrum SP3 represents the photocurrent signal IR of the third comparative example.

[0099] In the third comparative example, beat frequency components are generated over a wide frequency band based on the interrelationship of frequencies f1, f2, f3, and f4. In particular, the beat frequencies fb6 and fb7 in the figure are, for example, values ​​of "fb6 = f4 - f1, fb7 = f1 + f2", which are close to the frequency range of f1 to f4.

[0100] Therefore, in this third comparative example, when the cutoff frequency ft of the high-pass filter 115 is set as shown in the figure, the beat frequency component cannot be sufficiently reduced, and the error caused by the beat phenomenon in the measurement signal VL increases. Furthermore, when the cutoff frequency ft of the high-pass filter 115 is made higher than the beat frequency fb6, the component near frequency f1 is also attenuated in the high-pass filter 115, and the error in the measurement signal VL still increases.

[0101] In addition, in the present comparative example, in order to supply the light sources 102, 152 with driving currents of different frequencies, a power source corresponding to the alternating current power source 104 needs to be provided for each frequency. In addition, in the light receiving section 41 or the signal processing circuit 111 (refer to Figure 5 ), a unit that separates these frequencies is needed. Therefore, in the present comparative example, there is also the problem of the structure of the device becoming complicated and the cost becoming high.

[0102] [Third Embodiment]

[0103] Next, the automatic analysis device of the third embodiment will be described. In the following description, the same reference numerals are assigned to portions corresponding to the respective parts of the above-described other embodiments, and the description thereof will be omitted at times.

[0104] The structure of the automatic analysis device of the third embodiment is the same as that of the automatic analysis device 1 (refer to Figure 1 , Figure 2 ) of the first embodiment or the automatic analysis device 2 (refer to Figure 5 ) of the second embodiment. However, in the first and second embodiments described above, the direct current voltages VI, V21 output from the direct current power sources 103, 153 are fixed values, and in contrast, in the present embodiment, the difference is that the direct current power sources 103, 153 vary the direct current voltages VI, V21.

[0105] That is, the direct current power sources 103, 153 of the present embodiment set the direct current voltages VI, V21 to a first level that is relatively high at the timing when the energization of the light sources 102, 152 is started. Thereafter, as the time of the energization of the light sources 102, 152 elapses, the level of the direct current voltages VI, V21 is gradually lowered, and when the time of the energization reaches a predetermined time, the direct current voltages VI, V21 are set to a second level that is lower than the first level.

[0106] Here, the significance of varying the direct current voltages VI, V21 as described above will be described. In order to extend the life of the light sources 102, 152, it is preferable to make the direct current components of the driving currents I3, I23 as small as possible within a range in which the desired light emission characteristics are obtained. However, if the direct current components are suppressed, a long time is needed until the temperature of the light sources 102, 152 reaches a certain temperature. The light emission characteristics of the light sources 102, 152 are affected by the temperature of these elements. Therefore, if the direct current components of the driving currents I3, I23 are simply suppressed, the following problem arises: a long time is needed until the light emission characteristics of the light sources 102, 152 stabilize.

[0107] In the present embodiment, at the timing at which the light sources 102, 152 are started to be energized, the direct current component of the drive currents I3, I23 is increased, and thus the temperature of the light sources 102, 152 can be rapidly increased to the vicinity of the above certain temperature. Thereafter, the level of the direct current component is gradually decreased, and when the energization time reaches the predetermined time, the direct current component is suppressed to the size corresponding to the second level. Thus, according to the present embodiment, the light emission characteristics of the light sources 102, 152 can be rapidly stabilized, and the long life of the light sources 102, 152 can be realized.

[0108] [Effects of Embodiments]

[0109] According to the above embodiment, the automatic analysis device 1 includes a first light source (102) that irradiates light to a sample (44), a drive circuit (101) that supplies a first drive current (I3) whose frequency (f1-f2) is intermittently or continuously varied to the first light source (102), a light receiver 113 that outputs a light detection signal (IR) based on light transmitted through the sample (44), and a signal processing circuit 111 that demodulates the light detection signal (IR) in accordance with the frequency (f1-f2) of the first drive current (I3) and outputs a measurement signal VL based on the demodulation result.

[0110] In addition, from another viewpoint, the embodiment is an automatic analysis method having a process of irradiating light from a first light source (102) to a sample (44) by supplying a first drive current (I3) whose frequency (f1-f2) is intermittently or continuously varied to the first light source (102), outputting a light detection signal (IR) based on light transmitted through the sample (44), and demodulating the light detection signal (IR) in accordance with the frequency (f1-f2) of the first drive current (I3) and outputting a measurement signal VL based on the demodulation result. Thus, in the embodiment, even when an interference component VD is mixed in the light detection signal (IR), the influence of the interference component VD can be appropriately suppressed in the measurement signal VL.

[0111] In addition, more preferably, the automatic analysis device 2 further includes a second light source (152) that irradiates light to the sample (44) and is different from the first light source (102), and the drive circuit (151) supplies a second drive current (I23) having the same frequency (f1-f2) as the first drive current (I3) to the second light source (152). Thus, the measurement results in a wide wavelength band can be obtained using a plurality of light sources, and the influence of the beat phenomenon can be appropriately suppressed.

[0112] Further, it is more preferable that the first drive current (I3) is a pulsating current having a direct current component and an alternating current component, the drive circuit (101) has a direct current component control section (103) that controls the direct current component and an alternating current component control section (104) that controls the alternating current component, the signal processing circuit 111 has a high pass filter 115 that attenuates components below a cutoff frequency ft that is lower than a lowest frequency (fl) of the alternating current component among frequency components of the light detection signal (IR), and the direct current component control section (103) has a function of reducing the direct current component as the energization time to the first light source (102) elapses. Thus, the first light source (102) can be rapidly heated to rapidly stabilize the light emission characteristics, and the current supplied to the first light source (102) can be suppressed thereafter to achieve long life of the first light source (102).

[0113] [Modified example]

[0114] The present application is not limited to the above-described embodiments, and various modifications can be made. The above-described embodiments are example embodiments illustrated for easy understanding of the present application, and are not limited to necessarily having all the structures described. Further, a part of the structure of one embodiment can be replaced with the structure of another embodiment, and the structure of one embodiment can be added with the structure of another embodiment. Further, a part of the structure of each embodiment can be deleted, or other structures can be added or replaced. Further, the control lines and information lines shown in the drawings represent parts considered necessary for explanation, and do not necessarily show all the control lines and information lines necessary for products. In fact, it can be considered that almost all the structures are connected to each other. Modifications that can be made to the above-described embodiments are, for example, the following modifications.

[0115] (1) In each of the above-described embodiments, as an example of the sample, the case where the reaction solution 44 is applied is described. However, the sample is not limited to the reaction solution 44, and can be various solids, liquids, or gases.

[0116] Explanation of reference numerals

[0117] 1, 2 automatic analysis device 44 reaction solution (sample)

[0118] 101, 151 light source drive circuit (drive circuit) 102 light source (first light source)

[0119] 103 direct current power supply (direct current component control section)

[0120] 104 alternating current power supply (alternating current component control section)

[0121] 111 signal processing circuit

[0122] 113 light receiver

[0123] 115 high-pass filter 152 light source (second light source)

[0124] I3 drive current (first drive current)

[0125] IR photocurrent signal (light detection signal)

[0126] VL measurement signal

[0127] f1 frequency (lowest frequency)

[0128] f2, f3, f4 frequencies

[0129] ft cut-off frequency

[0130] I23 drive current (second drive current).

Claims

1. An automatic analyzing apparatus characterized by comprising: Possessing: a first light source that irradiates a sample with light; a drive circuit that supplies the first light source with a first drive current that varies discontinuously or continuously in frequency; a light receiver that outputs a light detection signal based on light transmitted through the sample; and a signal processing circuit that demodulates the light detection signal in accordance with the frequency of the first drive current and outputs a measurement signal based on the demodulation result; wherein the first drive current is a pulsating current having a direct current component and an alternating current component, the drive circuit possesses a direct current component control section that controls the direct current component and an alternating current component control section that controls the alternating current component, the signal processing circuit possesses a high-pass filter that attenuates components of the light detection signal that are below a cutoff frequency that is lower than the lowest frequency of the alternating current component, the direct current component control section has a function of reducing the direct current component as the elapsed time of energization to the first light source passes.

2. The automatic analysis device according to claim 1, characterized in that: the automatic analysis device further possesses a second light source that irradiates the sample with light and is different from the first light source, the drive circuit supplies the second light source with a second drive current that has the same frequency as the first drive current. having the processes of:

3. An automated analysis method characterized by, irradiating a sample with light from a first light source by supplying the first light source with a first drive current that varies discontinuously or continuously in frequency; outputting a light detection signal based on light transmitted through the sample; and demodulating the light detection signal in accordance with the frequency of the first drive current and outputting a measurement signal based on the demodulation result; wherein the first drive current is a pulsating current having a direct current component and an alternating current component, controlling the direct current component and controlling the alternating current component, attenuating components of the light detection signal that are below a cutoff frequency that is lower than the lowest frequency of the alternating current component, reducing the direct current component as the elapsed time of energization to the first light source passes. ​ ​

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