JPS6126012B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a preheating type electronic thermometer having a function of preheating a temperature sensing element.

Conventionally, in electronic thermometers, a temperature-sensitive probe is inserted into the measuring section, the rate of increase in temperature of the temperature-sensitive element detected moment by moment is monitored, and the measurement is terminated when this rate of increase reaches a predetermined value. The temperature of the thermosensing element at that time is displayed as the measured body temperature by displaying a certain value, or the thermosensor is preheated in advance to compensate for the drawdown of body temperature, and then the probe is inserted into the measurement site and detected. Some devices are designed to end the measurement when the temperature becomes stable, or use a timer to end the measurement after a certain period of time, and use the temperature of the temperature sensing element at that time as the body temperature.

However, in the case of the former, the temperature-sensing element temperature changes as shown in line a in Figure 1, and it takes a longer time for it to approach body temperature than line b, which shows the temperature of the preheated type temperature-sensing element, and moreover, at the beginning (before the measurement starts). The curve will deviate greatly depending on the temperature of the thermosensor, so if you try to increase the accuracy by reducing the surging value, the measurement time will increase, and if you try to shorten the measurement time, the surging value will increase. The disadvantage is that the measurement error increases. In addition, with the latter preheating type, waiting until the temperature stabilizes will take a long time to measure body temperature, and when using a timer, the preheating temperature must be set to stabilize the temperature within the set time. There is the trouble of having to control it so that it remains constant.

This invention was made in view of the above-mentioned drawbacks, and it preheats the temperature sensing element, monitors the rate of change in temperature of the temperature sensing element, and measures the temperature when the rate of change in temperature of the temperature sensing element reaches a predetermined value. By displaying the measured body temperature, the measurement time is shortened and the measurement accuracy is improved.

In other words, even if it is a preheating type electronic thermometer, since only a part of the probe (temperature-sensing element part) is preheated, a slight drawdown phenomenon of body temperature occurs, and this causes the phenomenon shown in Figure 1b. As shown in Figure 1a, which shows a part of the line enlarged, in the vicinity where the rate of change in temperature suddenly decreases, the temperature of the thermosensing element once drops below the true body temperature, and then tends to approach the body temperature again. By first investigating the rate of temperature change at which the true body temperature is reached, and using the temperature of the thermosensor when this rate of change is reached as the measured body temperature, it is possible to shorten measurement time and improve measurement accuracy. This is to stabilize the body temperature, and if the temperature of the thermosensing element subsequently rises above the measured body temperature, the previously measured body temperature is corrected, thereby making it possible to detect a more accurate body temperature.

Embodiments of the present invention will be described below using block diagrams. Figure 2 shows a hardware control system composed of discrete circuits.
Reference numeral 1 denotes a temperature-sensitive temperature-sensitive element with a preheating mechanism, and the output of this temperature-sensitive element 1 is amplified by an amplifier 2, and converted into a digital signal corresponding to the temperature of the temperature-sensitive element 1 by an A/D converter 3. . 4 is a latch circuit, and this latch circuit 4 takes in the temperature signal 3a outputted from the A/D converter 3 in response to a latch signal 5b from the control circuit 5 and temporarily stores it. Reference numeral 6 denotes a comparator, which compares the temperature signal 4a stored in the latch circuit 4 with the temperature signal 3a from the A/D converter 3 at the timing of the comparison signal 5c from the control circuit 5. By comparison, when 4a≦3a, the set signal 6a is output and the flip-flop 7
is set to "1", and when 4a<3a, an acquisition signal 6b is output to cause the latch circuit 4 to acquire a new temperature signal 3a. 8 is a display circuit which, when the flip-flop 7 is set to "1", takes in the temperature signal 4a stored in the latch circuit 4, converts it into a display signal, and then displays it on the display. Further, when the flip-flop 7 is set to "1", the output of the latch signal 5b from the control circuit 5 is prohibited.

In the above configuration, when the power switch (not shown) of the device is turned on to measure body temperature, the flip-flop 7 is first reset by the signal 5a from the control circuit 5, and the latch signal 5b is reset.
and the comparison signal 5c are output at a constant cycle with a predetermined time interval T between them. A/D converter 3
The temperature signal outputted from the latch circuit 5b is taken into the latch circuit 4 and temporarily stored, and the temperature signal 4a and the temperature signal 3a after T time are compared in the comparator 6. In comparator 6, 4a≦3
As can be seen from the line b in Figure 1, the rate of temperature change is larger at the beginning, so there is no output from the comparator 6 at first, and the signal from the control circuit 5. The above operation is repeated by 5b and 5c, and temperatures close to body temperature are sequentially taken in. When the temperature drops to around point A in the graph of FIG. 1a, the minimum unit of the output of the A/D converter 3 becomes 4a=3a, and the comparator 6 first outputs the set signal 6a. That is, the comparator 6 monitors the temperature change rate 3a-4a/T by determining whether the temperature change 3a-4a within time T has become 0 or less, and this temperature change rate is When the temperature falls below a predetermined value (determined in advance by setting time T so that the temperature change within time T becomes 0 near point A in the figure), the set signal 6a is output. This signal 6a sets the flip-flop 7, and the temperature signal stored in the latch circuit 4 is taken into the display circuit 8 and displayed on the display, and the latch signal 5b from the control circuit 5 is
The temperature signal stored in the latch circuit 4 is held. Therefore, even if the temperature of the temperature sensing element decreases thereafter (between A and B in Fig. 1a),
The displayed temperature does not change, and the display is corrected only when the temperature increases, as described below. That is, when the temperature rises (between C and D in the figure) and the comparator determines that 3a>4a, the acquisition signal 6b is output, the AND gate 9 is opened, and the latch circuit 4 receives a new temperature signal 3a. >Take in 4a. Since the flip-flop 7 has already been set, this captured temperature is immediately displayed on the display.

In this way, the rate of temperature change near point A, which is close to the true body temperature, is checked in advance and the latch signal 5b and comparison signal 5 are set.
The output interval T of c is set appropriately, and 4a=3a
Since the measured temperature is displayed when the temperature is stabilized, a value close to the true body temperature is displayed before the temperature stabilizes, and together with preheating, the measurement time is shortened, and the temperature is Since the display is corrected when the temperature rises, measurement accuracy also improves.

Next, an embodiment in which the present invention is applied to an electronic thermometer in which various controls are performed by software using a microprocessor will be described based on the flowchart shown in FIG.

First, in the first step S1, when the power switch of the device is turned on and measurement is started, the display on the display is first reset in step S2, and the flag F is cleared in step S3, and the preset data is stored in the memory M2. Set a large value X. Next, in step S4, the temperature of the sensor at that point in time is measured and the data is read, and in step S5, the data is stored in the memory M.
1 and proceed to step S6. Step S
6, data DAT1 of memory M1 and memory M2
data DAT2, but first the data
Since DAT2 has been set to a large value X, the answer is NO and the process moves to step S7. In step S7, it is determined whether the flag F is "1", but since F=O was initially set in the above step S3, it is determined NO, and the process proceeds to step S8, where the data DAT in the memory M1 is
1 to memory M2. Next, in step S9, after waiting for a certain period of time using a timer, the process jumps to step S4 again. In step S6 below
The above operation is repeated until it is determined that DAT1≧DAT2, and when YES is determined in step S6, the process moves to step S10 and flag F is set to "1". Next, the process advances to step S11, where the current data, that is, the data DAT1 in the memory M1, is displayed on the display.
The process moves to step S8 and the display data DAT1 is transferred to the memory M2. However, the above operation is repeated again, but in step S6 DAT1<DAT2
At this time, flag F has already been set, so the process jumps from step S7 to step S9, and
When DAT1≧DAT2, new data DAT1 is sequentially displayed and transferred to memory M2.

As explained above, the electronic thermometer according to the present invention preheats the temperature sensing element and focuses on the rate of change in temperature of the temperature sensing element during the drawdown phenomenon of body temperature. By monitoring the temperature and displaying the temperature when the rate of change becomes smaller than a predetermined value as the measured body temperature, the measurement time is shortened and the measurement accuracy is stabilized. Since the previously measured body temperature is corrected if the temperature of the thermosensing element increases, more accurate body temperature can be detected. Also, instead of displaying the temperature of the temperature sensing element at the time when the rate of change of body temperature of the temperature sensing element becomes completely 0 from an analog perspective (point B in Figure 1a), the rate of change of temperature is checked as in the example. By setting the rate of change appropriately and displaying it at point A in Figure 1a, the drop in body temperature due to drawdown can be compensated for.
The effect is similar to that of glaze, and by this,
It is possible to display a temperature closer to the true body temperature in a shorter time.

[Brief explanation of the drawing]

Figure 1 is a graph showing how the temperature of the temperature sensing element changes when the temperature sensing element is preheated and when it is not preheated. FIG. 3 is a timing chart of the main parts thereof, and FIG. 4 is a control flowchart of the second embodiment of the present invention. 1... Temperature sensing element, 4... Latch circuit, 5... Control circuit, 6... Comparator, 7... Flip-flop, 8... Display circuit.

Claims (1)

[Claims] 1. A temperature sensing probe having a temperature sensing element, a preheating means for preheating the temperature sensing probe to a temperature higher than the body temperature, and a preheating type electronic thermometer that measures the body temperature in the process of decreasing the temperature after completion of preheating. A means for determining the rate of change in temperature by detecting it at predetermined time intervals, a comparison means for detecting when the determined rate of change has become less than a predetermined value, and a feeling when detected by the comparison means. a storage means for storing and storing the temperature of the heating element as a measured body temperature; an updating control means for comparing the stored measured body temperature and updating the measured body temperature when a temperature higher than the body temperature is detected; A preheating type electronic thermometer comprising a display means for displaying the measured body temperature.