WO1987002876A1 - DEVICE FOR DETERMINING THE BASAL TEMPERATURE CURVE - Google Patents

Abstract

A device for determining the basal temperature curve (31) and the days when conception is possible. The device includes an instrument for measuring the inner temperature of the body, a processor which can record and process the inner temperature values of the body measured daily against the measurement date, a display and operation unit and if need be a clock and alarm function. This device is characterized by the fact that the processor, in order to determine when the ovulation has taken place, first compares a series of consecutive most recently measured temperature values, the number of which may be predetermined, with an initial temperature value determined in such a way that more than half of the temperature values measured at the beginning of the cycle are at least 0.1oC lower than the initial temperature value. When more than half of the temperatures most recently measured are higher than the initial value, the processor verifies against a second temperature value which is 0.1oC higher than the initial value which series of measured temperature values has for the first time more than half of its temperature values equal to or higher than the second control temperature and displays the day when the first temperature value of this series was measured as the day of ovulation. Ovulation can thus be reliably determined even when artefacts (temperature disturbances) occur.

Description

 Description

Apparatus for irradiation of the basal emperature curve

Technical area

The invention relates to a device for determining the basal temperature curve and for determining the conception days, with a device for measuring the body core temperature, an evaluation unit in which the daily measured body core temperature values can be stored and evaluated in association with the measurement date, and a display and Control unit and possibly a clock and alarm function.

Furthermore, the invention relates to a device for measuring the body core temperature and to a battery operated device for measuring and evaluating temperatures.

State of the art

Devices according to the preamble of claim 1 are known for example from US-PS 4,151,831, US-PS 4,377,171 or DE 32 21 999 AI.

Although electronic thermometers have been proposed at the present time, within very short measuring times of less than one minute, very accurate measurements with an accuracy of at least 0.1 ° C. are proposed. Measuring tolerances of 25/1000 ° C are required, as required for the measurement of basal body temperature in women and the determination of the conception day. But so that such accurate thermometer can be used meaningfully for this purpose, an evaluation is required by the appropriate facilities, the possible Uncertainties that are not due to the physical temperature measurement switches off.

A significant uncertainty factor in the conception determination results from the relatively complex evaluation of the multiplicity of basal measurements. So far only guarantees the experience of the gynecologist, with knowledge of exceptional temperature shifts, as z. As can be caused by medication, disease, fever, etc., to make a reliable statement about the conception. The evaluation of the measured temperature data is therefore only optimal if, with a relatively small storage volume, all combination cases that can occur can be correctly assessed in the medical sense.

The basal temperature curve is basically subdivided into individual cycles, the duration of which extends from the beginning of a menstrual period to the next. Each normal cycle consists of two main sections, the first postmenstrual, which is between 36.3 ° C and 36.8 ° C, taking into account the temperature fluctuations, and the second praemenstrual, which takes into account the temperature fluctuations between 36.9 ° C and 37.4 ° C is. Accordingly, the mean values of the post- and pre -mentru- mental cycles also vary, and thus can not be assumed to be constant. The first half of the cycle ends with ovulation, followed by a temperature rise of 0.2 C to 0.6 ° C. Often it comes directly before a Kurven¬ minimum, which can last one to three days. The last day of this low phase before the beginning of the climb is considered the most likely ovulation day.

The problem in determining the critical temperature As a result of ovulation, a similar increase in temperature can be caused by a number of other causes. Thus, even a slight illness, a journey or any unfortunate events, as well as intensive mental occupation, eating, consumption of alcohol or insufficient sleep can lead to a rise in body temperature of up to 0.5 ° C.

The mature follicle usually jumps on the fifteenth day before menstruation, it is be¬ fertile for up to 24 hours. The self-motile sperm normally retain the ability to fertilize the follicle in the uterine tract for three days. Therefore, the conception is possible only up to three days before and up to one day after the follicle jump. Thus, when the ovulation day is known, a distinction can be made precisely between fertile and infertile days. With the temperature method, however, only an already occurring follicular jump can be detected, so that only the following days until the next menstrual period can be classified as infertile with high reliability. A reliable prediction of the follicle jump is not possible. Therefore, the conception probability before ovulation can only be determined by extrapolation of the temperature data of past cycles. The definition of the World Health Organization for the transition from the low to the high temperature level of the basal temperature curve is: "A significant increase in temperature is characterized by the fact that it takes place within 48 hours or less and that the temperatures of three consecutive days are at least 0.2 ° C higher than in the previous six days ". This criterion of the World Health Organization for a significant rise in temperature in the basal temperature curve occurs only in ideal cases Cases that are very rare. The basal temperature curve, which is composed of the measured and stored temperature works, is called not only by disturbed temperature values, artifacts, which are caused by illness and excitement, but also by missing measurement data and by deviating measurement data, which are caused by fever , changed. In addition, the evaluation device must clearly highlight the two different temperature levels of the basal temperature curve and filter out disturbing fluctuations without distorting the curve.

Such filtering can be done, for example, with a low-pass function, which must be determined on the basis of measured discrete temperature data. A fundamental possibility is to calculate a new value for each measured temperature value, which results from the mean value of a certain number of data before and after this value. The width of this data field, called window or row, determines the strength of the low-pass characteristic. With it the degree of leveling of disturbed temperature values can be determined. Is the window or row wide and the contents z. For example, if there are nine to eleven values, then temperature disturbances of two to three days are also filtered out if their amplitudes are not far beyond the normal values. On the other hand, a narrow data window leaves greater fluctuations, since a wrong value exerts a strong influence on the mean value.

It would therefore be possible to move such a data window over a basal temperature curve and thereby set value by value by the respective average result. In this way, a wide data window paves the way Curve well, but also blurs the temperature jump in the middle of the cycle. The beginning of the cycle with elevated temperature can therefore never be calculated exactly. A narrow data window preserves this jump characteristic, but also leaves false temperature jumps, since abnormal temperatures (fever etc), which are also referred to as artifacts, are not sufficiently filtered out. The evaluation of the measured temperature values according to the screening method has - as has been recognized according to the invention - such considerable defects that no satisfactory solution is possible with it.

Presentation of the invention

The invention is therefore based on the object, a device according to the "preamble of claim 1 in such a way that even in the presence of disturbed Tempera.turwerte the temperature jump in the middle of the cycle detected with certainty and from this the most likely Ovulationstag can be determined.

An inventive solution to this problem is characterized by its developments in the claims.

The advantages of the invention are, in particular, that the device according to the invention detects the temperature jump of 0.2 ° C undistorted and accurately between the cycle with low and the cycle with high temperature level. For this purpose, a data window, ie a series of successive measured values of the body core temperature, is considered, which, however, does not replace the individual measured temperature value with an average result of the preceding and following values. Furthermore, according to the invention, it is only judged whether a temperature value has a certain height has reached, but not what amplitude he has achieved.

It probably needs no further explanation that a highly accurate measurement of the body core temperature is required for a reliable determination of the e pfängniskrist and contraception days. In the measurement of the basal temperature curve in particular a fast response and the smallest possible systematic Me߬ error is a prerequisite for a reliable measurement.

For this reason, German Patent Application P 35 27 942, for example, does not describe how a sensor must be designed to measure reproducible temperature values in as short a time as possible. The Ergeb¬ between the measured temperature values of the temperature sensor is influenced by the holder to which the Tempera¬ tursensor for handling ^'and is mounted for use. This holder particularly influences the dynamic behavior of the temperature sensor. The state of the art corresponds to the generally prevailing view that a good conductive temperature sensor must be attached to a very poorly conductive holder in order to extract as little heat as possible from the temperature sensor. A Fiebermeßfühler recently published on the market, which has been constructed strictly according to this principle, makes it clear by its transient behavior that - as erfin¬ has been recognized according to this principle - this principle is disadvantageous. Precisely because the holder consists of poorly heat-conducting material, it heats up only very slowly and, even after several minutes, absorbs heat from the temperature sensor, which is prevented from reaching its final temperature value, namely the body core temperature. The invention is therefore based on the further object of developing a device for measuring body core temperature in such a way that the response is improved, systematic measurement errors are reduced and the required measurement time is significantly reduced

An inventive solution to this problem is characterized gekenn¬ with their developments in the claims 9 to 15.

According to the invention, the device for measuring the body core temperature consists of the actual temperature sensor, an intermediate part and a handle for handling the device.

The sensor should have the lowest possible heat capacity and the best possible thermal contact between the sensor element and the sensor housing; advantageous, for example, a large-scale solder joint between the two.

The intermediate part is contrary to the prevailing opinion of a material with the best possible thermal conductivity, e.g. from a thin-walled metal tube.

The handle, on the other hand, consists of a poorly heat-conductive material, for example a plastic or a foam.

This design results in the temperature distribution curve shown in FIG. 6, in the realization of which the general concept of the invention is contained; In this case, the objective realization may differ from the above-described. The basic principles according to the invention can also be applied to probes which are preheated prior to insertion into body cavities or also heated during the measurement. Examples of such heated devices are described in the earlier mentioned earlier patent application, DE 32 20 124 Äl or in claim 15. The device specified in claim 15 has the particular advantage that it is very easy to implement.

In particular, in the basal body temperature measurement for the detection of fertility-free and low-risk days, for example, for biological contraception, it is necessary to measure the body core temperature very accurately and with a high reproducibility for years. On the other hand, since daily temperature measurement is required in biological contraception due to basal body temperature measurement, the use of a stationary mains-operated temperature measuring device is not recommended. In order to ensure a daily Temperatur¬ measurement, the temperature and Auswertemeßgerät should be small tand handy and not dependent on an external power supply, so have their own supply battery or a Versorgungsakku.

On the other hand, the high-precision measurement of temperatures with battery-operated devices at changing locations raises considerable measurement problems, which result inter alia from the fluctuating, temperature-dependent supply voltage, large fluctuations in the ambient temperature and the energy capacity of the supply battery that is low due to the battery operation.

The invention therefore continues to be based on the object de to provide a battery-operated device for measuring temperatures, which ensures a very high resolution, good Reproduzier¬ availability and high long-term stability of the measurement even with fluctuating, tempe¬ raturabhängigen supply voltages and large fluctuations of the ambient temperature over long periods.

A solution according to the invention of this object is indicated by its developments in the claims 16 following ge.

Surprisingly, this object can be achieved in that of a device according to the preamble of claim 16, that is, a device with a measuring bridge, in which a temperature-dependent resistance was used ,, assumed and this device by the characterizing part of claim 16 specified features is developed. The device according to the invention is based on the following statement:

A basal body temperature measurement, which provides a largely safe indication of non-fertile days, must be a highly accurate and reproducible temperature measurement with an accuracy in the range of 36-42 ° C in the range of 0.025 ° C. Among other things, to achieve such accuracy with battery powered devices over long periods of time, it is necessary to compensate for offset voltage variations of the amplifier due to aging and / or temperature effects. The use of operational amplifiers whose offset voltage is age- and temperature-compensated, ie, for example, by so-called chopper amplifiers, is disadvantageous because of the high cost of such amplifiers Furthermore, it is not possible to use high-precision and highly stabilized reference voltage sources for temperature measurement, since the energy consumption of such voltage sources would be too great a load on the battery.

Therefore, the invention uses as a temperature sensor on a sensor whose resistance value changes depending on temperature. This sensor is switched in a manner known per se into a half or full measuring bridge. Since the "detuning" of the measuring bridge is small, especially in the case of small temperature measuring ranges, as required for measuring the basal temperature, it is not necessary to apply a highly stabilized voltage to the measuring bridge. Under certain circumstances, it is even sufficient according to claim 3, if the battery voltage is applied directly to the measuring bridge without additional stabilization measures. Due to the measuring bridge circuit, it is only necessary to compensate for the significant offset voltages of integrated semiconductor amplifications which occur due to ambient temperature and / or time influences, since such compensation either involves the use of expensive amplifiers or of According to the invention, use is made of an operational amplifier in which no special measures are taken for zero-point and temperature compensation, and the offset error voltage is compensated by the measuring principle described below:

For this purpose, three switches are provided whose switching state controls a control unit. Depending on the switching state, the first switch applies the reference voltage or the reference potential to the bridge. Is the reference potential applied? lies between the Eingangskle men of Operationsverstär¬ kers no external voltage. The occurring output voltage is thus the offset voltage amplified by the amplification factor of the operational amplifier. If, on the other hand, the reference voltage is applied to the measuring bridge, then the output voltage is the "sum voltage" amplified by the amplification factor of "bridge voltage" and "offset voltage".

By subtracting the output voltage value occurring at the applied reference potential from the output voltage value when the reference voltage is applied, the actual "bridge voltage" -naturally amplified by the amplification factor-is thus obtained, which is a measure of the temperature of the temperature sensor. This subtraction of the two output voltage values makes it possible in a simple and cost-effective manner to achieve the inventive design claimed in features (c) and (d) of claim 16 ^' . In addition, the design according to the invention has the advantage that the energy consumption is low and, on account of the low energy consumed in the temperature sensor, its self-heating can also be neglected. Compared with known circuits can be reduced by a factor of 10 2 to 103 with respect to known devices according to the preamble of claim 1 with a suitable choice of the measurement time / pause ratio of the energy consumption. Correspondingly, the self-heating of the sensor is reduced, which is extremely advantageous, especially for measurements in biological tissue.

Further developments of the invention are specified in the claims 17 ff.

In claim 17 is a simple and inexpensive Formation of the memory circuit geknnzeichnet, in addition - since no active elements such as in a sample and hold circuit are required - further reduces energy consumption. As storage capacitors, it is possible to use any capacitors which are free of so-called post-polarization, ie in which voltages do not build up again in the interior after discharge of the capacitor.

The device according to the invention has a surprisingly high long-term stability and measuring accuracy. Therefore, it is possible to apply the output voltage of the battery without additional stabilization measures to the bridge as a reference voltage (claim 18). As a result, the power consumption of the device according to the invention is further reduced. Of course, it can be particularly ^{advantageous'} in this Zusammen¬ hang to use battery types whose output voltage as little as possible changes in discharge.

The control circuit, which controls the switching state of the individual switches, can in principle be constructed as desired and switch over the individual switches in a fixed clock ratio. For this purpose, it can have, for example, a clock generator whose output signal assumes a plurality of states in a predetermined clock ratio, by which the switching of the individual switches takes place (claim 19).

However, it is particularly advantageous to use the microprocessor circuit according to claim 20 for temperature calculation as a control circuit for the switches. The microprocessor circuit can be an internal clock or a special sequence program whose length is known exactly, for controlling the switching states on point.

However, it is particularly advantageous if the microprocessor circuit determines the number of measurements per time unit corresponding to the measured temperature change rate (claim 22):

You. almost stationary case, ie at low Temperatur¬ changes per unit time, then correspondingly fewer M-editions are required than at rapid Temperaturände¬ ments .. This further reduces the burden of Versorgungsbat¬ terie and thus increases the battery life.

In any case, it is particularly advantageous if the switches are electronic switches, since such switches can be actuated by the control unit or the microprocessor circuit without much effort and with low power consumption.

The "clocked" measurement, which carries out the device according to the invention, is particularly advantageously combined with a digital display, since the storage effect of such digital displays compensates for "display fluctuations" of the device according to the invention over a certain "interrogation time".

As a digital display while an LCD display is advantageously used, since in such a display, the power consumption and thus the battery load is low.

Of course, the device according to the invention can be used for arbitrary temperature measurements. The inventions In accordance with the advantages achieved, however, are particularly pronounced in a battery-powered handset, which is used to measure body temperature and in particular the basal body temperature. In the latter case, the microprocessor circuit can also perform additional functions and, for example, display days free of cures via the digital display.

Short description of the drawing

The invention will be explained in more detail below with reference to the drawing, in which:

FIG. 1 shows a basal temperature curve which has been evaluated according to the average method,

Figure 2 is a basal temperature, which has been evaluated by the ^inventions' to the invention device,

FIG. 3 shows a device according to the invention for measuring the body core temperature,

FIG. 4 shows an equivalent circuit diagram of this device,

FIG. 5 shows the temperature absorption curves of the sensor and the components of the holder,

Figure 6 shows the temperature distribution curves for the sensor and the holder at different times.

Figure 7 is a block diagram of a device according to the invention and

8 shows the signal formation in the dargestell¬ th in Figure 7 device. Way to carry out the invention

FIG. 1 shows the evaluation of a basal temperature curve with the average method. A window width of seven days has been used, i. in each case seven consecutive temperature measured values are considered, wherein value for value of the measured temperatures has been replaced by the respective average result. In the basal temperature curve according to FIG. 1, an artifact, that is to say a disturbed temperature value, has been recorded on the seventh and eighth day. The result of the evaluation with the average method of the basal temperature curve 31 is shown with the drawn crosses 32 and their connection to a curve. It can be clearly seen that the artifact on the seventh and eighth day causes a significant error in the evaluation of the basal temperature curve.

FIG. 2 is based on the same basal temperature curve 31 as in FIG. 1, an artifact likewise being recorded on the seventh and eighth day. The evaluation circuit of the device according to the invention, which consists, for example, of a microprocessor with RAM and ROM memories, a memory, a clock with alarm device and a display device for the measured and stored temperature values, leads more closely to the following explained operations, the discrete version of the electronic evaluation circuit is not shown here.

The device according to the invention also works to evaluate the basal temperature curve with a window function. Wide windows have the disadvantage that the double-ten- To find jump between the cycle with the low and the cycle with the high Temperaturiyiyeau later, since of them correspondingly more high Temperaturwer¬ te must be detected in order to recognize at least half of all values at the same level. For this reason, an average window width of seven temperature values was selected. This means that up to three artefacts per window can be filtered out and that the temperature jump in the middle of the cycle is recognized at the latest on the day after it starts. A normal cycle begins with a low temperature phase, therefore, the temperature value of the low temperature phase of the cycle is first started. For this purpose, a certain starting value is assigned to the data window, ie the series of consecutive temperature values that are jointly considered for the evaluation, which was placed at the beginning of the cycle curve. This starting value is referred to as the first temperature threshold value and set so that it is safely below the expected temperature level of the postmenstrual phase. The temperature level of the first temperature threshold value is then compared with each individual temperature value detected by the data window and counted as many values are at or above this first temperature threshold value. If it is more than half of all temperature values detected by the window, then the post-menstrual temperature level has not yet been found. The temperature thresholds for the next run of the window are each increased by a constant amount, namely by 0.1 ° C and compared again in the next run with each temperature er¬ detected by window. This comparison is made from the beginning of the cycle on the measured and stored data and in a stepwise manner, each step associated with a defined temperature threshold is. This comparison with repeatedly increased temperature threshold values of the window is repeated until, for the first time, less than half of these temperature values lie at or above the temperature level of the data window. Thus, a level of the temperature threshold of the window is reached, which is referred to value with second Temperaturschwell¬. This second temperature threshold is 0.1 ° C above the level of the postmenstrual phase. In order to determine the temperature jump of at least 0.2 ° C., it is then checked in an additional run of the data window without increasing the temperature threshold value (ie with the second temperature threshold value) if more than half of all temperature values are equal to or greater than the second temperature threshold value , The data window with the second temperature threshold value is therefore pushed at the currently determined level, step by step, towards the end of the cycle. If it is true that more than half of all window temperature values are equal to or greater than what was the case when the window was pushed into the high temperature level of the premenstrual phase, then the window is returned to the start location at the beginning of the cycle again increase the associated temperature threshold of the window by 0.1 ° C, which is referred to as the third temperature threshold, again to seek the beginning of the higher temperature phase of the praemenstruellen cycle. The third temperature threshold is now exactly 0.2 ° C above the postmenstrual phase. If more than half of the temperature values of the window are at the same or higher level in the last step with a third tempera ture threshold value assigned to the window during the passage, the location of the first temperature value of this window is stored. From this point, the first temperature value is sought whose amplitude at least at the same level as the temperature level of the window, so the third temperature threshold is. As a result, the starting point of the two-tenth jump has been found between the post-menstrual cycle and the pre-menstrual cycle.

To determine the Ovulationstages the curve minimum of the basal temperature curve is used, which occurs mostly before the temperature jump of 0.2 ° C and lasting about one to two days. The last day within this postmenstrual phase with a low temperature level before the beginning of the slope is considered a probable ovulation day. For its determination, the period is now examined, which extends three days before the start day of the pre-menstrual phase and up to three days thereafter. The evaluation begins on the third day of the pre-menstrual phase and passes through these seven temperature values in the direction of the beginning of the cycle in order to find the temperature value and the place with the lowest temperature value. The day which first corresponds to this value is initially the ovulation day determined by approximation. Since perturbations can only increase core core temperature, with two or more minimum temperature values within that time period, the one closest to the end of the cycle is the critical one. Namely, the high temperature level of the premenstrual phase begins only after the ovulation day, and health disorders can not normally lower the temperature.

The device according to the invention for evaluating the basal temperature curve filters out temperature fluctuations through a broad window of seven temperature values without changing the respective measured and stored absolute values of the temperatures. This will tenth-step not blurred in this process. In addition, since only checks whether the measured Tem¬ peraturwerte have reached a certain height, but not more Ampli¬ tude of temperatures even in the Be¬ bill comes in, the dominance ^'of the artifacts is no longer important.

It must additionally be noted that at the start of the cycle in the postmenstrual phase a drop in temperature is to be expected, which converts the high temperature level of the premenstrual phase into that of the postmenstrual phase. Therefore, the data window for finding the postmenstrual temperature values is set not to the first position of the cycle, but to the fifth position, thereby neglecting the first four temperature values within each cycle. In the most cases, this leads to no error, since four values already suffice for the evaluation at a low level, but a post-menstrual phase duration of less than eight days can not occur. During evaluation of the basal temperature curve, the data window cycles through the fifth day cycle with a temperature threshold of 0.1 ° C, the second temperature threshold, above the postmenstrual phase to the end of the cycle to ensure that it is the temperature jump is not a long-lasting disturbance that would be detected at a premature temperature drop. Since a decrease in the temperature must be expected at the cycle time, only nine temperature values are checked with the data window at the two-tenth level, ie the third temperature threshold value. Fever and missing data are eliminated simply by widening each window of data until there are seven pieces of no-fault data in it. The method according to the invention of the evaluation unit for evaluating the measured and stored temperature values of a basal temperature curve has been used in the illustration according to FIG. The basal temperature curve 31 was evaluated with a window with a total of seven data of temperatures. The evaluation of the basal temperature curve 31 according to the mode of operation according to the invention is carried out by the crosses 33 or by the curve drawn by these crosses. From the evaluation curve with the crosses 33, it is quite clear that the device according to the invention can clearly determine the beginning of the tenth of a second and also the day of ovulation. FIG. 2 also shows a data window 35, which extends over seven temperature values, and also the start tag 34 of this data window.

In order to be able to measure, for example, the measurement of the basal temperature as reliably as possible, it is necessary that the measured and stored temperature values can not be influenced at all or only very slightly by the heat supply or heat removal caused by the holder of the sensor.

Therefore, FIG. 3 shows a device according to the invention for measuring the body core temperature or the basal temperature, in which a temperature sensor 1 is fastened to a holder, this holder consisting of an intermediate part 36 and a handle 37. Here, as the prior art, the general opinion prevails that a good heat-conducting temperature sensor must be attached to an extremely poorly conductive holder in order to extract as little heat as possible from the temperature sensor. A Fiebermeßfühler, which was constructed strictly according to this principle, is up recently come to the market. Its transient behavior makes it clear that this principle does not prove itself. Just because the holder is made of poor thermal conductivity material, it heats up only very slowly and takes after several minutes of heat from the temperature sensor, which is prevented from reaching its final temperature, namely the body core temperature.

In one measurement, not only the temperature sensor a-itself, but a much larger part of the device is in contact with the heated tissue. This fact, which makes use of the invention, allows a wesent¬ Lich more favorable construction. If a part of the holder, namely the intermediate part 36, following the tempera ture sensor 1 made of a good heat conducting metal tube and thereby selected the wall thickness so thin that the heat capacity per unit area of the intermediate part is smaller than in the temperature sensor 1, then The intermediate part 36 also heat up faster than the temperature sensor 1 and therefore can even give off heat to it. The prerequisite for this, however, is that the intermediate part 36 is made large enough to be able to cover even the low heat flow, which is absorbed by the subsequently attached poorly conductive handle 37.

FIG. 3 shows this device according to the invention, which is constructed from a temperature sensor 1, an intermediate part 36 and a handle 37. In this case, the temperature sensor 1 and the intermediate part 36 are in contact with the measurement object 6. FIG. 4 shows a simplified equivalent circuit of the electronic thermometer embodied according to the invention. TK means the body core temperature. The resistor 38 and the capacitor 39 form the Ersatz¬ circuit diagram for the sensor, the resistor 40 and the Capacitance 41 form the equivalent circuit diagram for the intermediate part 36 and the resistor 42 and the capacitance 43 form the equivalent circuit diagram for the handle 37.

FIG. 5 shows the transient curves of the characteristic volume elements of the electronic thermometer, namely the temperature sensor 1, the intermediate part 36 and the handle 37. These volume elements can be assumed to be uninfluenced by the temperature gradients in the middle part. From this, temperature distribution curves for the entire electronic thermometer can be derived, which are plotted in FIG. 6 for different times.

The required for the evaluation of the measured temperature values microprocessor can also control or regulate a possible heating of the intermediate part and the sensor at the same time. , ^*

Figure 7 shows an inventive device having a measuring bridge (1), in which a temperaturabhändiger resistor (2), for example, a platinum resistor, a thermistor, etc. is used. As a supply or reference voltage, the terminal voltage of the battery (3) also used for the voltage supply is applied to the bridge circuit via an electronic switch (4). The bridge voltage is applied to the input terminals of an operational amplifier (5) connected in a known manner, the output terminal of which is connected via switches (6) and (7) to one terminal of a capacitor (8) or one input terminal of a subtractor (9) , The capacitor (8) is further connected via the switch (7) with the other input terminal of the subtractor (9) connectable. The output terminal of the subtractor (9) is connected via an analog / digital converter (10) with a microprocessor circuit designated by the reference numeral (11) which also controls the switching state of the switches via an I / O connection. Furthermore, a digital display (12) is provided.

The operation of the circuit shown in Figure 7 will be explained in more detail below with reference to Figure 8.

FIG. 8 (A) shows the profile (V) of the bridge voltage (Pb) as a function of the time (t) as a result of a temperature change of the temperature-dependent resistor. To the Zeit¬ points Tl, T2, ... switches the microprocessor circuit (11) ^* the electronic switch (4) for a very ^'short time, in which neither the measurement nor the offset error voltage of the amplifier changes to , so that the battery voltage is applied to the measuring bridge (1). At the output terminal of the amplifier, the superposition of the amplified offset voltage and the bridge voltage results in the signal shown in FIG. 8 (B). Since the reference potential is applied to the bridge with the exception of the short time periods (T1, T2,...), The output voltage of the amplifier is the amplification factor-boosted offset voltage whose time profile is shown by way of example in FIG. 8 (C).

The difference formation in the subtracter (9) illustrated in FIG. 8 (D) results in the amplified bridge voltage shown in FIG. 8 (E), without drifting zero-point etc. of the amplifier having influenced the result. FIG. 8 (F) shows the energy requirement or the current as a function of time. As F.igur.8 (F) can be seen, the energy requirement is reduced by a large factor as a result of the interrogation of the measuring bridge, which takes place only at certain points in time, with respect to circuits in which the reference voltage is applied continuously to the bridge. In many applications, it is sufficient if the supply voltage is applied for 10 -5 to 10-6 seconds and the

Measured values are to be interrogated at intervals of 1/10 s. In this case, the energy requirement can be reduced approximately by a factor of 10 3 to 104.

Above, the invention has been described with reference to a Ausführungsbei¬ game without limitation of niederge¬ in the claims laid down general inventive concept.

Claims

Patent claims 1. A device for determining the basal temperature curve and for determining the conception days, with a device for measuring Kδrperkerntempera- ture, an evaluation unit in which the daily measured body core temperature values in association with the measurement date can be stored and evaluated, and a display and Bedie¬ tion unit, as well as possibly a clock and Weckfunk¬ tion, characterized in that the evaluation unit for determining the ovulation egg first compares a series of measured, successive temperature values whose number is specifiable ver¬, with a temperature starting value, they from the measured temperature value series at the beginning of the cycle has been determined such that more than half of the temperature values measured at the beginning of the cycle by at least 0.1 ° C is less than the temperature starting value, and that the evaluation unit, if more than half the last measured temperature value of this row is greater than the starting value, mi t at 0.1 ° C compared to the start If the second temperature value increases, the number of temperature values which is shifted from the beginning of the cycle to the end of the cycle or to the current measuring day is for the first time more than half of the measured temperature values equal to or greater than the second temperature value and determining the day of measurement of the first temperature value of this series, which is at least at the level of the second temperature value, as the center of a new series in which the minimum representing the ovulation day is calculated, wherein at the time of occurrence several minimums that are next to the cycle. 2. Device according to claim 1, characterized in that the evaluation unit for determining the temperature starting value starts with an initial value which is certainly below the temperature value of the premenstrual phase and this value at each check of the initial temperature value Row increased by a constant amount. 3. A device according to claim 2, characterized in that the increase of the initial temperature value in steps of 0.1 ° C takes place. 4. Device according to one of claims 1 to 3, characterized in that the number of last measured nen temperature values, which are compared with the temperature starting value, seven. 5. Device according to one of claims 1 to 4, characterized in that the series of temperature values must be met on the second temperature value to the end of the cycle, and so false Temperautursprünge not be evaluated final. 6. Device according to one of claims 1 to 5, characterized in that when evaluating the temperature values contained in a row, the evaluation unit does not evaluate their mean value, but only checks whether the temperature value has reached a certain size. 7. Device according to one of claims 1 to 6, characterized in that the determination of the temperature start value begins only with the temperature value measured on the 5th day after the beginning of the cycle. 8. Device according to one of claims 1 to 7, characterized in that fever and missing data are eliminated by the number of Temperaturwer¬ te a row is increased until there are seven data without disturbances in the series. 9. A device for measuring the body core temperature of living beings with a holder for gripping the sensor insebsondere for use in conjunction with a device according to one of claims 1 to 8, characterized in that the holder of a Zwischen¬ part (36) and an actual handle (37), which is connected to the temperature sensor via the intermediate part, that the heat capacity of the intermediate part (36) per unit area is smaller than the heat capacity of the Tempera¬ tursensors (1), and that the thermal conductivity of the intermediate part is large. 10. The device according to claim 9, characterized in that the intermediate part consists of a good thermal conductivity, thin-walled metal tube. 11. The device according to claim 9 or 10, characterized in that the handle (37) is poorly wärme¬ conducting. 12. Device according to one of claims 9 to 11, characterized in that the intermediate part (36) is designed so large that it applies the small from the intermediate part (36) in the handle (37) flowing heat flow. 13. Device according to one of claims 9 to 12, characterized in that the intermediate part and the temperature sensor are heatable before insertion into a body cavity to a temperature which is in the range of temperatures to be measured. 14. Device according to one of claims 9 to 13, characterized in that the intermediate part and the temperature sensor are heated during the measurement. 15. The apparatus according to claim 14, characterized in that a constant heating power can be applied to the intermediate part and the temperature sensor, and the determination of the body temperature by Ermitt¬ ment of the "break point" of the time change of gemes¬ senen temperature value. 16. Battery-operated device for measuring temperatures with a temperature sensor whose ohmic resistance value changes as a function of temperature, and which is connected in a branch of a full or half measuring bridge, to which a reference voltage is applied, and whose bridge voltage is an amplifier whose Ausgangs¬ signal is a measure of the temperature to be measured, in particular for use with a device according to a of claims 1 to 15, characterized by the combination _. following features: (a) a first switch (4), depending on the switching state, applies to the bridge (1) the reference voltage or the reference potential, (b) an operational amplifier (5) without additional zero point and temperature compensation is used as the amplifier, (c) a second and a third switch (6,7) connect, depending on the switching state, the output terminal of the operational amplifier with a memory circuit (8) for the output voltage or the one input terminal of a subtractor (9) and the memory circuit with the other input terminal of the subtractor, (d) a control circuit (11) controls the switches such that in a first operating state the reference potential is applied to the measuring bridge and the memory circuit stores the offset output voltage of the operational amplifier, and in a second operating state the reference voltage at the Measuring bridge is applied and the subtractor of the output voltage of the operational amplifier subtracts the voltage stored in the memory circuit voltage. 17. Device according to claim 16, characterized in that the memory circuit is a connectable via the second switch to the output terminal of the Opera¬ tion amplifier capacitor (8). 18. Device according to claim 16 or 17, characterized in that the output voltage of the battery is applied without additional stabilization to the bridge as a reference voltage. 19. Device according to one of claims 16 to 18, characterized in that the control circuit comprises a clock generator. 20. Device according to one of claims 16 to 19, characterized in that the AusgangsanSchluß of the subtractor is connected via an A / D converter with a Mikropro¬ zessorschaltung (11), which determines the temperature be¬. 21. Device according to claim 20, characterized in that the microprocessor circuit also serves as a control circuit for the switches. 22. Device according to claim 20 or 21, characterized in that the microprocessor circuit determines the number of measurements per unit time according to the measured temperature change rate. 23. Device according to one of claims 16 to 22, characterized in that the switches (4,6,7) are electronic switches. 24. Device according to one of claims 16 to 23, characterized in that a digital display (12) is provided for the measured temperature value. 25. Use of a device according to one of claims 16 to 24 in a battery-powered hand-held device for measuring the body temperature of living beings.