TWI458979B - Biosensor having a function of environment temperature compensating and method thereof - Google Patents

Description

Biochemical sensor for compensating environmental temperature effect and method thereof

The present invention relates to a biochemical sensor, and more particularly to a biochemical sensor that utilizes a temperature sensor to compensate for detection results.

Figure 1 shows a functional block diagram of a conventional biochemical sensor. The biosensor 200 includes two electrodes 211 and 212, a reference voltage source 220, a current voltage conversion circuit 230, an analog digital conversion circuit 240, a processor 250, and a display 260. In an embodiment, a timer 270 and a temperature sensor 280 may be further included. The reference electrode contact point 211 is for electrically connecting the reference electrode 11a of the biochemical test strip 100, and the working electrode contact point 212 is for electrically connecting the working electrode 11b of the biochemical test strip 100. The reference voltage source 220 can be a ground terminal. The reference electrode 11a is electrically connected to the reference voltage source 220 through the reference electrode contact point 211, and the working electrode 11b is electrically connected to the analog digital conversion circuit 240, the current-voltage conversion circuit 230, and the processor 250 through the electrode 212. Display 260 is electrically coupled to processor 250. The timer 270 is used for counting, and the temperature sensor 280 is disposed inside the biochemical sensor 200 for measuring the ambient temperature.

When the measurement is performed, the biochemical test piece 100 is inserted into the biochemical sensor 200 to generate a voltage difference between the reference electrode 11a of the biochemical test piece 100 and the working electrode 11b, thereby measuring a current. The analog digital conversion circuit 240 and the current voltage conversion circuit 230 convert the aforementioned current into a signal that the processor 250 can process, and calculate a blood glucose concentration based on the aforementioned signal. The temperature sensor 280 senses the ambient temperature, and the processor 250 compensates the aforementioned blood glucose concentration according to the aforementioned temperature, thereby obtaining a relatively correct blood glucose concentration.

The biochemical sensor 200 of the prior art can take into account the influence of temperature on the blood glucose concentration, and obtain a relatively correct blood glucose concentration. However, there is still room for improvement in the biochemical sensor 200 according to the prior art.

It is an object of an embodiment of the present invention to provide a biochemical sensor. It is an object of an embodiment of the present invention to provide a biochemical sensor capable of measuring a relatively correct temperature.

According to an embodiment of the invention, a biochemical sensor is provided, which is adapted to couple a biochemical test piece to detect a sample. The biochemical sensor comprises a first temperature sensor, a second temperature sensor, an analog to digital conversion circuit and a processor. The first temperature sensor is adapted to measure a first temperature, the second temperature sensor is adapted to measure a second temperature, and the analog digital conversion circuit is coupled to the first temperature sensor and the second temperature sensor The processor is coupled to the analog digital conversion circuit. And the processor receives the first temperature and the second temperature processed by the analog digital conversion circuit, and determines a measurement processing program according to the first temperature and the second temperature.

According to an embodiment of the invention, a biochemical sensing method is provided for use in a biochemical sensor having a first temperature sensor and a second temperature sensor for measuring a sample. The biochemical sensing method includes the following steps. A first temperature and a second temperature are respectively measured by using the first temperature sensor and the second temperature sensor. A measurement processing program is determined according to the first temperature and the second temperature.

In an embodiment, the measurement processing program includes the following steps. It is determined whether the absolute value of the difference between the first temperature and the second temperature is greater than a predetermined threshold. When the absolute value of the difference between the first temperature and the second temperature is greater than a preset threshold, a temperature estimation value is calculated according to the first temperature and the second temperature. Determining whether the temperature estimate is between a first operating temperature and a second operating temperature. When the temperature estimation value is between the first operating temperature and the second operating temperature, the biochemical sensor is combined with the biochemical test piece to detect the sample. Preferably, the measurement processing program further comprises the step of displaying a warning symbol on a display of the biochemical sensor when the temperature estimation value exceeds the first operating temperature or the second operating temperature.

In an embodiment, the measurement processing program includes the following steps. A biochemical sensor is used to measure a measurement of the aforementioned sample. The measured value of the sample is compensated by the first temperature and the second temperature to calculate a compensation value of the measured value of the sample.

In an embodiment of the biochemical sensor and the biochemical sensing method, the first temperature sensor and the second temperature sensor are both disposed inside the biochemical sensor, and the thermal time constant of the first temperature sensor Different from the thermal time constant of the second temperature sensor, the first temperature sensor and the second temperature sensor form a different temperature return curve.

In an embodiment of the biochemical sensor and the biochemical sensing method, the first temperature sensor is disposed inside the biochemical sensor, and the second temperature sensor is disposed outside the biochemical sensor, and the first The thermal time constant of the temperature sensor is the same as or different from the thermal time constant of the second temperature sensor, so that the first temperature sensor and the second temperature sensor form a different temperature return curve.

Other objects and advantages of the present invention will become apparent from the technical features disclosed herein. The above and other objects, features, and advantages of the invention will be apparent from

2 is a functional block diagram of a biochemical sensor in accordance with an embodiment of the present invention. As shown in FIG. 2, the biochemical sensor 300 includes a pair of electrodes 311 and 312, a reference voltage source 320, a current-voltage conversion circuit 330, an analog-to-digital conversion circuit 340, a processor 350, a display 360, and a The first temperature sensor 381 and a second temperature sensor 382. In an embodiment, a timer 370 may further be included. The electrode 311 is used to electrically connect the reference electrode 11a of the biochemical test strip 100, and the electrode 312 is used to electrically connect the working electrode 11b of the biochemical test strip 100. The reference voltage source 320 can be a ground terminal. The reference electrode 11a is electrically connected to the reference voltage source 320 through the electrode 311, and the working electrode 11b is electrically connected to the analog-to-digital conversion circuit 340, the current-voltage conversion circuit 330, and the processor 350 through the electrode 312. Display 360 is electrically coupled to processor 350 for use in counting.

The first temperature sensor 381 and the second temperature sensor 382 can be, for example, a thermistor, and are disposed inside the biochemical sensor 300 for measuring the ambient temperature. The thermal time constant of the first temperature sensor 381 is different from the thermal time constant of the second temperature sensor 382.

When the measurement is performed, the biochemical test piece 100 is inserted into the biochemical sensor 300 to generate a voltage difference between the reference electrode 11a of the biochemical test piece 100 and the working electrode 11b, thereby measuring a current. The analog digital conversion circuit 340 and the current voltage conversion circuit 330 convert the aforementioned current into a signal that the processor 350 can process, and calculate a blood glucose concentration measurement value based on the aforementioned signal. The first temperature sensor 381 and the second temperature sensor 382 respectively sense a first temperature T1 and a second temperature T2 of the ambient temperature, and the processor 350 determines the first temperature T1 and the second temperature T2 according to the first temperature T1 and the second temperature T2. A measurement process. In an embodiment, the blood glucose concentration measurement value may be further compensated according to the first temperature T1 and the second temperature T2, thereby obtaining a relatively correct blood glucose concentration compensation value.

In an embodiment, it is preferable to determine whether the absolute value of the difference between the first temperature T1 and the second temperature T2 is greater than a predetermined threshold, and the absolute value of the difference between the first temperature T1 and the second temperature T2. When the threshold value is greater than the preset threshold, an environmental temperature estimation value is calculated according to the first temperature T1 and the second temperature T2. Finally, the aforementioned blood glucose concentration compensation value of the blood glucose concentration measurement value is calculated according to the foregoing environmental temperature estimation value.

In general, the use of a temperature sensor under normal operating conditions is sufficient to measure the correct ambient temperature, but with a dramatic change in ambient temperature, such as from a midday sun, with biochemical sensor 300 When entering the air-conditioned room from outside, due to the limitation of the mechanism, the air inside the biochemical sensor 300 cannot be convected rapidly with the outside air, and the temperature of the temperature sensor is slow. If the user immediately measures, the cause will be Measuring the wrong temperature results in a compensation error, resulting in a large error measurement.

Figure 3 shows a temperature sensor with a different thermal time constant, a plot of time and temperature sensor readings. As shown in FIG. 3, when the ambient temperature changes drastically, the first temperature sensor 381 and the second temperature sensor 382 change with temperature, because the thermal time constants of the two are different, and the temperature of the two is returned. Curves L1 and L2 will also differ. Therefore, at the same time, the first temperature sensor 381 and the second temperature sensor 382 measure the different first temperature T1 and the second temperature T2, and when the two temperatures are greater than a predetermined threshold, the utilization is utilized. The processor 350 calculates the ambient temperature according to the first temperature T1 and the second temperature T2, thereby calculating a relatively accurate environmental temperature estimation value Tetm (estimation), and the processor 350 further determines the blood glucose concentration according to the ambient temperature estimated value Tetm. The measured value is compensated to obtain a correct blood glucose concentration compensation value.

In addition, in an embodiment, the compensation procedure may not be performed, and only the current environmental temperature is determined according to the temperature estimation value Tetm, and the user is informed. In one embodiment, a biochemical sensing method can be used to measure blood glucose concentration. 4 is a flow chart showing a blood glucose concentration measuring method according to an embodiment of the present invention. The blood glucose concentration measurement method includes the following steps.

Step S02: The first temperature T1 and the second temperature T2 are respectively measured by the first temperature sensor 381 and the second temperature sensor 382. Preferably, the first temperature T1 and the second temperature T2 are measured at the same time t.

Step S04: determining whether the absolute value of the difference between the first temperature T1 and the second temperature T2 is greater than a predetermined threshold. In an embodiment, when it is determined that the absolute value of the difference between the first temperature T1 and the second temperature T2 is greater than a predetermined threshold, a warning message is displayed to notify the user to stop the operation, and wait for a predetermined time before re-operating At this time, it returns to step S02. In an embodiment, the operation of the temperature estimation value Tetm may also be performed, and the next step S06 may be performed.

Step S06: Calculate a temperature estimated value Tetm according to the temperatures T1 and T2. The function of time and temperature according to Newton's Law of Cooling is as follows.

T(t)=Tend+(T0-Tend)*exp(-t/τ)

In the above formula, t represents time, Tend represents the final temperature (ie, ambient temperature), T0 represents the initial temperature, exp() is an exponential function, and τ is a thermal time constant. At a known time t, for example, at 5 minutes, the first temperature sensor 381 and the second temperature sensor 382 are sampled to obtain a first temperature T1 and a second temperature T2, respectively. Therefore, T1 and T2 are known, time t is also known, and τ ₁ and τ ₂ are also known as the thermal time constants of the first temperature sensor 381 and the second temperature sensor 382, respectively. The following two equations.

T1(t)=Tend+(T0-Tend)*exp(-t/τ ₁ )

T2(t)=Tend+(T0-Tend)*exp(-t/τ ₂ )

Among them, the final temperature (that is, the ambient temperature) Tend and the initial temperature T0 are unknown. Since there are two equations and two unknowns, the final temperature Tend and the initial temperature T0 can be obtained, and the final temperature Tend is the temperature predicted value Tetm of the ambient temperature. It should be understood that, in an embodiment, the first temperature sensor 381 and the second temperature sensor 382 may also be sampled at different times t1 and t2, since both t1 and t2 are already It is to be understood that the calculation formula is as described above, and thus the related description is omitted.

Step S08: determining whether the temperature estimated value Tetm is between a first operating temperature Tlm (lower limit) and a second operating temperature Tum (upper limit).

Step S10: When the temperature estimation value Tetm is between a first operating temperature Tlm and a second operating temperature Tum, the biochemical sensor 300 is combined with the biochemical test strip 100 to perform a measurement procedure of the liquid to be tested.

Step S12: when the temperature estimated value Tetm exceeds the first operating temperature Tlm or the second operating temperature Tum (that is, the temperature estimated value Tetm is not within the range of the first operating temperature Tlm or the second operating temperature Tum), then the display A warning symbol of high temperature or low temperature is displayed on the 360 to warn the user of the current environment, and the ambient temperature has exceeded the specification of the biochemical sensor 300.

Figure 5 shows a functional block diagram of a biochemical sensor in accordance with an embodiment of the present invention. The biochemical sensor 400 of the embodiment of FIG. 5 is similar to the biochemical sensor 300 of the embodiment of FIG. 2, and therefore the same elements are denoted by the same reference numerals, and the related description is omitted. As shown in FIG. 5, in the embodiment, the first temperature sensor 381 and the second temperature sensor 382 have the same thermal time constant, and are respectively disposed inside and outside the biochemical sensor 300, and the first temperature. The sensor 381 is used to measure the temperature inside the biochemical sensor 300, and the second temperature sensor 382 uses the temperature outside it. When the temperature of the environment and the temperature inside the biochemical sensor 400 are substantially the same, the first temperature sensor 381 and the second temperature sensor 382 measure substantially the same temperature. However, when the temperature of the environment and the temperature inside the biochemical sensor 400 are too large, there will be two different rewarming curves. The first temperature and the second temperature measured at the same time will also be different. Therefore, at the first temperature T1 and the second temperature T2, when the two temperatures are greater than a predetermined threshold, the processor 350 calculates a relatively accurate temperature estimation value Tetm according to the first temperature T1 and the second temperature T2. To replace the readings T1 and T2 of the temperature sensor. In addition, in an embodiment, the first temperature sensor 381 and the second temperature sensor 382 may also have different thermal time constants.

In addition, sometimes the ambient temperature does not change, but when the user grips the biochemical sensor 400 for a long time, since the body temperature is greater than the ambient temperature, the temperature inside the biochemical sensor 400 rises, so the first temperature sensor 381 senses The first temperature T1 and the second temperature sensor 382 sense that the second temperature T2 is greater than the ambient temperature, but the TI is different from T2. At this time, the biochemical sensor 400 continues to operate, and an incorrect blood glucose concentration measurement result is obtained, so that it can be determined whether the absolute value of the difference between the first temperature T1 and the second temperature T2 is greater than a predetermined threshold value. A warning symbol is displayed on the display 360 and the user is prohibited from performing a measurement procedure to prevent the user from measuring an incorrect blood glucose concentration.

According to an embodiment of the invention, two temperature sensors are used to sense the temperature. Preferably, two temperature sensors having different temperature-return curves are used to sense the temperature, and the biochemical sensor is further based on The temperature is measured and the subsequent measurement procedure is determined, so that a more accurate measurement can be measured.

While the present invention has been described in its preferred embodiments, the present invention is not intended to limit the invention, and the present invention may be modified and modified without departing from the spirit and scope of the invention. The scope of protection is subject to the definition of the scope of the patent application. In addition, any of the objects or advantages or features of the present invention are not required to be achieved by any embodiment or application of the invention. In addition, the abstract sections and headings are only used to assist in the search of patent documents and are not intended to limit the scope of the invention.

100. . . Biochemical test piece

11a. . . Reference electrode

11b. . . Working electrode

200. . . Biochemical sensor

211. . . Reference electrode contact point

212. . . Working electrode contact point

220. . . Reference voltage source

230. . . Current-voltage conversion circuit

240. . . Analog digital conversion circuit

250. . . processor

260. . . monitor

270. . . Timer

280. . . Temperature sensor

300. . . Biochemical sensor

311. . . Reference electrode contact point

312. . . Working electrode contact point

320. . . Reference voltage source

330. . . Current-voltage conversion circuit

340. . . Analog digital conversion circuit

350. . . processor

360. . . monitor

370. . . Timer

381. . . First temperature sensor

382. . . Second temperature sensor

400. . . Biochemical sensor

Figure 1 shows a functional block diagram of a conventional biochemical sensor.

2 is a functional block diagram of a biochemical sensor in accordance with an embodiment of the present invention.

Figure 3 shows a temperature sensor with a different thermal time constant, a plot of time and temperature sensor readings.

4 is a flow chart showing a blood glucose concentration measuring method according to an embodiment of the present invention.

Figure 5 shows a functional block diagram of a biochemical sensor in accordance with an embodiment of the present invention.

100. . . Biochemical test piece

11a. . . Reference electrode

11b. . . Working electrode

300. . . Biochemical sensor

311. . . Reference electrode contact point

312. . . Working electrode contact point

320. . . Reference voltage source

330. . . Current-voltage conversion circuit

340. . . Analog digital conversion circuit

350. . . processor

360. . . monitor

370. . . Timer

381. . . First temperature sensor

382. . . Second temperature sensor

Claims (12)

A biochemical sensor is adapted to be coupled to a biochemical test piece for detecting a sample, the biochemical sensor comprising: a first temperature sensor adapted to measure a first temperature; and a second temperature sense The detector is adapted to measure a second temperature; an analog-to-digital conversion circuit coupled to the first temperature sensor and the second temperature sensor; and a processor coupled to the analog-to-digital conversion circuit The processor receives the first temperature and the second temperature processed by the analog-to-digital conversion circuit, and determines a measurement processing program according to the first temperature and the second temperature, wherein the measurement processing program includes Determining whether the absolute value of the difference between the first temperature and the second temperature is greater than a predetermined threshold; when the absolute value of the difference between the first temperature and the second temperature is greater than the preset threshold, according to the Calculating an ambient temperature estimate value for a temperature and the second temperature; determining whether the ambient temperature estimate is between a first operating temperature and a second operating temperature; and when the ambient temperature estimate is interposed At the first operating temperature and Between the second operating temperature, so that complex biochemical sensor detecting the biological test piece The specimen. The biosensor of claim 1, wherein the first temperature sensor and the second temperature sensor are both disposed inside the biosensor, and the first temperature sensor is The thermal time constant is different from the thermal time constant of the second temperature sensor. The biochemical sensor of claim 1, wherein the first temperature sensor is disposed inside the biochemical sensor, and the second temperature sensor is disposed outside the biochemical sensor And the thermal time constant of the first temperature sensor is the same or different from the thermal time constant of the second temperature sensor. A biochemical sensing method is applied to a biochemical sensor having a first temperature sensor and a second temperature sensor for measuring a sample, the biochemical sensing method comprising: utilizing the first temperature The sensor and the second temperature sensor respectively measure a first temperature and a second temperature; and determine a measurement processing program according to the first temperature and the second temperature, wherein the measurement processing program includes : causing the biochemical sensor to measure a measured value of the sample; and compensating the measured value of the sample by using the first temperature and the second temperature to calculate a compensation value of the measured value, And the step of calculating a compensation value of the measured value includes: determining whether the absolute value of the difference between the first temperature and the second temperature is large And a preset threshold; when the absolute value of the difference between the first temperature and the second temperature is greater than the preset threshold, calculating an ambient temperature estimate according to the first temperature and the second temperature; And calculating the compensation value of the measured value according to the estimated value of the ambient temperature. The biosensing method of claim 4, wherein the first temperature sensor and the second temperature sensor are both disposed inside the biosensor, and the first temperature sensor is The thermal time constant is different from the thermal time constant of the second temperature sensor. The biochemical sensing method of claim 4, wherein the first temperature sensor is disposed inside the biochemical sensor, and the second temperature sensor is disposed outside the biochemical sensor And the thermal time constant of the first temperature sensor is the same as or different from the thermal time constant of the second temperature sensor. A biochemical sensing method is applied to a biochemical sensor having a first temperature sensor and a second temperature sensor for measuring a sample, the biochemical sensing method comprising: utilizing the first temperature The sensor and the second temperature sensor respectively measure a first temperature and a second temperature; and determine a measurement processing program according to the first temperature and the second temperature, wherein the measurement processing program includes : Determining whether the absolute value of the difference between the first temperature and the second temperature is greater than a predetermined threshold; when the absolute value of the difference between the first temperature and the second temperature is greater than the preset threshold, according to the first Calculating an ambient temperature estimate value for the temperature and the second temperature; determining whether the ambient temperature estimate is between a first operating temperature and a second operating temperature; and when the ambient temperature estimate is between When the first operating temperature and the second operating temperature are between, the biochemical sensor is coupled to the biochemical test piece to detect the sample. The biochemical sensing method of claim 7, wherein the measuring processing program further comprises: when the ambient temperature estimated value exceeds the first operating temperature or the second operating temperature, the biochemical sense A warning symbol is displayed on a display of the detector. The biosensing method of claim 7, wherein the first temperature sensor and the second temperature sensor are both disposed inside the biochemical sensor, and the first temperature sensor is The thermal time constant is different from the thermal time constant of the second temperature sensor. The biochemical sensing method of claim 7, wherein the first temperature sensor is disposed inside the biochemical sensor, and the second temperature sense The detector is disposed outside the biochemical sensor, and the thermal time constant of the first temperature sensor is the same as or different from the thermal time constant of the second temperature sensor. The biochemical sensing method of claim 7, wherein the step of respectively measuring a first temperature and a second temperature comprises: using the first temperature sensor and the second at the same time The temperature sensor measures a first temperature and a second temperature, respectively. The biochemical sensing method of claim 7, wherein the measuring processing program comprises: displaying a warning message when determining that the absolute value of the difference between the first temperature and the second temperature is greater than a predetermined threshold .