JPS62200245A - Biochemical measuring apparatus - Google Patents

Abstract

PURPOSE:To eliminate large measuring errors, by providing a means for calculating a correlation between frequencies of a time counting pulse signal and a circuit operation pulse signal to detect any deviation when caused in the pulse frequency of an oscillator. CONSTITUTION:A value is calculated which is correlative to the frequencies of a time counting pulse signal and a circuit operation pulse signal and it is judged whether the value thus calculated is within a specified range or not. If no change is found in the frequencies of both pulse signals, the correlated value will be constant and also within a specified predetermined range. But when any abnormal deviation is fund in the frequency of any one pulse signal, the correlated value changes so much to be outside the specified range. If this happens, an error processing, for instance, an error display is done. For example, a CPU7 has a calibration curve table indicating correlations between received optical signals and sugar values in a built-in memory and has a function of reading a sugar value corresponding to a received light signal taken in, a function of checking abnormality in the frequency by determining both pulse signals of a system clock oscillator 13 and a timer oscillator 14, a function of processing errors in case of abnormality and the like.

Description

Detailed Description of the Invention (a) Industrial Application Field The present invention relates to a biochemical measurement device, particularly a microcomputer that receives pulse signals for timing and pulse signals for circuit operation (system operation) from separate oscillators. Regarding the adopted biochemical measuring device.

(b) Conventional technology In general, as a biochemical measuring device such as a blood analyzer, a test strip colored in response to a substance to be measured is attached to a detection section including a light emitter and a light receiver, and a microcomputer (hereinafter referred to as C.P.
The driver circuit is operated in response to a command from (referred to as U) to turn on the light emitter, and the light emitting signal is emitted onto the test paper and obtained from the light receiver.
There is a known method in which the degree of coloration of the reaction test paper is detected from the received light signal, and the substance to be detected is quantified from this degree of coloration. Conventionally, in this type of biochemical measuring device, the clock pulse signals used by the CPU for timekeeping and circuit operation are generated using separate oscillators (for example, a crystal oscillator for timekeeping and a CR oscillator for circuit operation).
There are inputs from This pulse signal for timing is used, for example, as a time count signal to turn on a buzzer to notify you after a predetermined time after a switch is turned on, and the pulse signal for circuit operation is used for the machine cycle of the CPU, etc. It is something that

(c) Problems to be solved by the invention In the above-mentioned biochemical measuring device, if the accuracy of the A/D converter is poor, variations will occur in the light reception signal taken into the CPU from the light receiver of the detection section, and If the accuracy of the timer built into the CPU is poor, for example, the set reaction time of the test strip will vary, causing a change in the degree of coloring of the test strip, and in either case, a deviation will occur in the measured value. On the other hand, A/
The D converter is controlled by the CPU's clock pulse signal for circuit operation, and the CPU's built-in timer uses the clock pulse signal for timekeeping, so if the frequency of these pulse signals becomes inconsistent, This will affect the accuracy of the A/D converter and timer, making it impossible to obtain accurate measured values.

However, in conventional biochemical measurement devices, no checks are performed on the frequency fluctuations of these pulse signals for timing and circuit operation, and even if there is frequency fluctuation, the measurement cannot be continued. Since the process continues, there is a problem in that any measurement errors that occur are overlooked.

In view of the above, it is an object of the present invention to provide a biochemical measurement device that detects deviations in the pulse frequency of an oscillator and does not cause large measurement errors.

(d) Means for Solving the Problems The biochemical measuring device of the present invention includes a first oscillator that outputs a pulse signal for time measurement, a second oscillator that outputs a pulse signal for circuit operation, and a second oscillator that outputs a pulse signal for circuit operation. A microcomputer that receives pulse signals from the first and second oscillators, a detection unit that includes a light emitter and a light receiver and to which a test strip is attached, a drive circuit that drives the light emitter, and a control from the microcomputer. An A/D converter that converts the received light output from the light receiver into a digital signal and inputs it to the microcomputer, wherein the microcomputer is provided with a pulse signal for clocking and a pulse signal for circuit operation. means for calculating a value correlated with frequency; means for determining whether the calculated value falls within a predetermined range; and error processing when the determining means determines that the value does not belong to the predetermined value. It is characteristically equipped with the means to do so.

(E) Function This biochemical measurement device calculates a value that correlates with the frequency of the pulse signal for timing and the pulse signal for circuit operation, and determines whether or not the calculated value falls within a predetermined range. .

If there is no change in the frequency of both pulse signals, the correlated value is also constant and falls within a predetermined range. However, if the frequency of either pulse signal shifts abnormally, its correlation value also changes and falls outside the predetermined range. If the correlation value falls outside a predetermined range, error processing, such as an error display, is performed.

(F) EXAMPLES The present invention will now be described in more detail with reference to examples shown in the drawings.

FIG. 3 is an external perspective view of a blood analyzer in which the present invention is implemented. This blood analyzer is a device for quantifying sugar contained in blood.

In FIG. 3, a test strip insertion slot 3 of a detection section 2, a display 4, a power switch 5, and a measurement start switch 6 are arranged on the upper surface of a case 1. In case 1, detection unit 2
A light emitting element (emitter) and a light receiving element (light receiver), as well as C
Electronic circuits such as PU are built-in.

FIG. 4 is a circuit block diagram of this embodiment device. On/off signals from the power switch 5 and the measurement start switch 6 are taken into the CPU 7. Further, the driver (drive circuit) 8 operates according to a command from the CPU 7, and the light emitting element 9 of the detection section 2 is driven to turn on, so that the light projected onto the test strip (not shown) is received by the light receiving element 10. It has become. The light-receiving current of the light-receiving element 10 is converted into a voltage value by a current/voltage conversion circuit 11, and further converted into a voltage value by an A/D converter circuit 11.
It is converted into a digital value by a converter 12 and then taken into the CPU 7.

The CPU 7 receives a system clock pulse signal from the system clock oscillator 13 and a time clock pulse signal from the timer oscillator 14, respectively. CPU
Reference numeral 7 carries out a machine cycle operation (circuit operation) based on the system clock pulse signal, and executes a timer operation in response to a clock pulse signal for timekeeping.

Furthermore, the CPU 7 stores a calibration curve table showing the correlation between the received light signal and the sugar content in its built-in memory, and has a function to read out the sugar value corresponding to the received light signal, that is, to quantify the sugar value, and a system clock. Oscillator 13 and timer oscillator 14
It has functions such as determining the correlation between both pulse signals, checking for frequency abnormalities, and performing error processing in the case of abnormalities. Details of these functions will be described later. Also CPU
7 is connected to the display 4 and the buzzer 15.

The display 4 is provided to display the determined sugar value, and the buzzer 15 is provided to make various notifications.

Next, the software configuration and operation of the embodiment apparatus will be explained with reference to flowcharts shown in FIGS. 1 and 2.

When the power switch 5 is turned on, the operation starts, and it is first determined whether the voltage of the battery (not shown) has become low (decreased below a predetermined value) [step ST (hereinafter referred to as ST)].
abbreviated as )1]. If it is determined that the battery voltage has decreased below the predetermined value, a low display is displayed on the display 4 (ST11). This display is performed by, for example, lighting up a battery-shaped mark.

If the battery voltage is OK in STI, a routine for checking the oscillation frequencies of the system clock oscillator 13 and timer oscillator 14 is entered (Sr1).

This oscillation frequency check routine will be detailed later.

Next, if there is no abnormality in the oscillation frequency according to the above check routine, that is, if the frequency calculated in the oscillation frequency check routine is within a predetermined value (Sr3), the display 4
Displays instructions for the stick set with test strips attached (Sr1). Upon seeing this display, the tester drops blood onto the test strip and turns on the measurement start switch 6 (Sr1).
Sr5).

In response to turning on the measurement start switch 6, the CPU 7 enters sample measurement (test paper measurement) processing (Sr1).

Specifically, this sample measurement process starts a timer, turns on the buzzer 15 after a predetermined time (e.g. 1 minute) to notify blood wiping, and then after a predetermined time (e.g. 1 minute) ) from the received light signal read through the A/D converter 12,
Calculate and quantify the sugar value by referring to the calibration curve table.

Next, it is determined whether there is a sample measurement error, that is, whether the quantitative value exceeds a predetermined value (Sr7).

If the quantitative value is within a predetermined value, it is determined that the measurement is normal, and the quantitative value is displayed on the display 4 (Sr1). However, if the quantitative value is not within a predetermined value, it is determined that the measurement is not normal, and a sample measurement error is displayed on the display 4 (Sr1). This completes the measurement of this sample.

Next, the measurement start switch 6 is turned on (ST10
) and return to Sr1 to prepare for the next sample measurement.

On the other hand, if Sr3 determines that the oscillation frequency is abnormal, a display indicating the oscillation frequency abnormality is displayed on the display 4 (ST12
). When this oscillation frequency abnormality display or the battery low display of 5T11 is displayed, the power is turned off after 30 seconds (ST13).

Next, the oscillation frequency check routine will be explained.

When this routine is entered, as shown in FIG. 2, the counter is initialized (5T21), the timer time T is set (ST22), and the timer operation is started (ST21).
T23). Subsequently, it is determined whether the timer end interrupt flag is on (ST24). This timer end interrupt flag is
As shown in FIG. 5, this is a flag that is turned on by hardware when the timer counts T seconds. Further, the 5T24 discrimination process is performed every M machine cycles, as shown in the flag detection timing in FIG.
If the judgment is NO, the counter is incremented (
Sr15), return to Sr14.

When the timer end flag is turned on when the pulse signal from the timer oscillator 14 counts for 1 second, the judgment of 5T24 is YES.
Then, the oscillation frequency f of the system clock oscillator 13 is calculated (ST26).

Now, the count value of the counter when the timer time T seconds has elapsed is C.
Then, the total number of machine cycles processed by the CPU in T seconds is MMC. On the other hand, this total number of machine cycles is f
It is also expressed as xT. Therefore, MXC=fXT.

is required.

Once this frequency f is calculated, the process returns to the main routine, and as described above, it is determined in ST3 whether or not the oscillation frequency is normal. If the frequency calculated by the above equation is within the preset frequency range of the system clock that can operate normally, any oscillator is considered to be normal. This is because if the oscillation frequency of either one goes out of order, T or C will fluctuate greatly and the frequency will no longer belong to the predetermined frequency range, and both frequencies will go out of order at the same time, and the frequency f will satisfy the above frequency range. This is because the probability of this is very small, and practically speaking, if the above f is not within a predetermined range, one of the oscillators can be considered to be abnormal.

In addition, in the above embodiment, a blood analyzer was used as an example, but
This invention can also be applied to other biochemical measuring devices such as a urine sugar needle.

(G) Effects of the Invention According to the present invention, a value is calculated to calculate a value that correlates with the frequency of a pulse signal for timing and the frequency of a pulse signal for circuit operation, and if the value is outside a predetermined range, Since error handling is performed, if an abnormality occurs in the timing oscillator or circuit operation oscillator, it is possible to avoid continuing measurement, thereby avoiding measurements with large errors. be able to.

[Brief explanation of drawings]

FIG. 1 is a main flow diagram for explaining the software configuration and operation of a blood analyzer according to an embodiment of the present invention, and FIG. 2 is a flow diagram showing an oscillation frequency check routine in the main flow diagram. 3 is an external perspective view of the blood analyzer of the same embodiment, FIG. 4 is a circuit block diagram of the blood analyzer, and FIG. 5 is a time chart for explaining the operation of the blood analyzer. 2: detection unit, 7: CPU (microcomputer), 8: driver, 9: light emitting element, 10: light receiving element, 12: A/D converter, 13 system clock oscillator, 14: timer oscillator. Patent applicant Tateishi Electric Co., Ltd. Agent
Patent Attorney Shigeru Nakamura Figure 2 Figure 3

Claims (1)

[Claims] (1) a first oscillator that outputs a pulse signal for timing;
a second oscillator that outputs a pulse signal for circuit operation; a microcomputer that receives the pulse signals from the first and second oscillators; and a detection section that includes a light emitter and a light receiver and to which a test strip is attached; A biochemical measuring device comprising: a drive circuit that drives the light emitter; and an A/D converter that converts the light output from the light receiver into a digital signal and inputs the digital signal to the microcomputer under control from the microcomputer. , means for calculating, in the microcomputer, a value correlated with the frequency of the pulse signal for timekeeping and the pulse signal for circuit operation; and means for determining whether the calculated value falls within a predetermined range; A biochemical measurement device characterized by comprising means for processing an error when the determination means determines that the value does not belong to a predetermined value.