Abstract:
An electronic thermometer including a probe to be inserted in to a portion of an outer ear to be measured by the thermometer, an infrared quantity detection means for detecting an infrared radiation quantity which is entered through the probe, a temperature computation means for applying the detected infrared radiation quantity in a predetermined computation expression to compute out a temperature such as body temperature, an infrared transmission data reading means for taking data corresponding to an infrared transmission quantity passing through the probe, and a control means for controlling the computation expression according to the taken data corresponding to the infrared transmission quantity.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    This invention relates to an electronic thermometer employing infrared radiation, and more particularly to an ear type clinical thermometer that detects an infrared radiation quantity radiated from a tympanum to measure body temperature.  
           [0003]    2. Description of the Related Art  
           [0004]    As shown in FIG. 1, there is well known an ear type clinical thermometer having a probe (an infrared radiation input unit)  1  mounted by a probe cover  2  for stain or contagion protection on measurement. In such a conventional clinical thermometer, infrared radiation passing through the probe  1  is detected by an infrared radiation sensor  3 , and applied to a CPU (central processing unit)  5  through an A/D (analog-to-digital) converter  4 . Internal temperature of the clinical thermometer is detected by a temperature sensor  6 , and applied to the CPU  5  through the A/D converter  4  in the same way. The CPU  5  detects temperature or body temperature based on the detected infrared radiation quantity and internal temperature to be indicated by a display  7 . In this kind of clinical thermometer, attenuation of infrared radiation by the probe cover  2  is considered to detect the temperature from the infrared radiation quantity detected by the infrared radiation sensor  3 . The conventional ear type clinical thermometer is designed to set a computation expression to correctly measure body temperature when the probe cover is mounted, but has a problem to indicate an abnormal measurement result when temperature is measured without mounting any probe cover.  
         SUMMARY OF THE INVENTION  
         [0005]    It is, therefore, a primary object of this invention to provide an electronic thermometer capable of precisely measuring temperature such as body temperature without affection by the presence or absence of a probe cover nor by the kind of the probe cover.  
           [0006]    According to this invention, there is provided an electronic thermometer including a probe to be inserted in to a portion of an outer ear to be measured by the thermometer, an infrared quantity detection means for detecting an infrared radiation quantity which is entered through the probe, a temperature computation means for applying the detected infrared radiation quantity in a predetermined computation expression to compute out temperature such as body temperature, an infrared transmission data reading means for taking data corresponding to an infrared transmission quantity passing through the probe, and a control means for controlling the computation expression according to the taken data corresponding to the infrared transmission quantity.  
           [0007]    The taken data corresponding to the infrared radiation transmission quantity includes, in addition to the data of an infrared radiation quantity having passed the probe, data of an infrared radiation quantity to be passed through the probe, and data correlating to these transmitted infrared radiation quantities. In this electronic thermometer, for instance, an infrared radiation quantity entering through the probe from a tympanum is detected by the infrared quantity detection means, and temperature (body temperature) is computed out by the temperature computation means according to a predetermined computation expression based on the detected infrared radiation quantity. The data corresponding to the infrared radiation quantity is taken by infrared quantity detection means, the computation expression is controlled by the taken data, for instance, constants are revised. Accordingly, even if an infrared radiation transmission quantity by the probe is different, right temperature (body temperature) can be measured by doing compensation by the difference. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]    Other objectives and advantages of this invention will be more readily apparent from the following detailed description provided in conjunction with the following figures, of which:  
         [0009]    [0009]FIG. 1 is a schematic block diagram of a conventional ear type clinical thermometer;  
         [0010]    [0010]FIG. 2 is a schematic block diagram of an ear type clinical thermometer as a preferred embodiment of this invention;  
         [0011]    [0011]FIG. 3 is a flow chart showing a main routine in an operation of the ear type clinical thermometer of the embodiment;  
         [0012]    [0012]FIG. 4 is a flow chart showing a routine to take data of an infrared radiation quantity of the ear type clinical thermometer of the embodiment;  
         [0013]    [0013]FIG. 5 is a schematic block diagram of a modification of the ear type clinical thermometer of the preferred embodiment in FIG. 1;  
         [0014]    [0014]FIG. 6 is a flow chart showing a routine to take data of an infrared radiation quantity of the modified ear type clinical thermometer;  
         [0015]    [0015]FIG. 7 is a flow chart showing a routine to take data of an infrared radiation quantity of an ear type clinical thermometer as another modification of the preferred embodiment;  
         [0016]    [0016]FIG. 8 is a flow chart showing a routine to take data of an infrared radiation quantity of an ear type clinical thermometer as still another modification of the preferred embodiment;  
         [0017]    [0017]FIG. 9 is a perspective partial view of a probe and a probe cover of an ear type clinical thermometer as still another modification of the preferred embodiment;  
         [0018]    [0018]FIG. 10 is a sectional view showing an operation of detection of an infrared radiation transmission quantity in the modified ear type clinical thermometer of FIG. 9;  
         [0019]    [0019]FIG. 11 is a flow chart showing a routine to take data of an infrared radiation quantity of the modified ear type clinical thermometer;  
         [0020]    [0020]FIG. 12 is a flow chart of an operation in an ear type clinical thermometer as a still another modification of the preferred embodiment of this invention;  
         [0021]    [0021]FIG. 13 is a flow chart of an operation in an ear type clinical thermometer as a still another modification of the preferred embodiment; and  
         [0022]    [0022]FIG. 14 is a flow chart of an operation in an ear type clinical thermometer as a still another modification of the preferred embodiment; 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0023]    Referring, now, to FIG. 2, there is shown a schematic block diagram of an ear type clinical thermometer as a first embodiment of this invention, which includes an infrared radiation (IR) input unit (probe)  1 , a probe cover  2 , an infrared radiation sensor  3 , an analog-to-digital (A/D) converter  4 , a central processing unit (CPU)  5 , a temperature sensor  6 , a display  7 , and an operation switch  8 . These components are same as those of the prior art of FIG. 1, but the thermometer of this embodiment is characterized by employing a probe cover detector  9  for detecting whether or not the probe cover  2  is mounted.  
         [0024]    The probe cover detector employs  9  may employ a switch, such as a button switch, a lead switch, an photoelectric switch and so forth, which is turned ON when the probe cover  2  is mounted. The thermometer of this embodiment stores therein a computation expression Tx=k×Ts+Ta, in which “k” represents a constant relating to an infrared radiation transmission quantity, “Ts” represents an infrared radiation sensor output, and “Ta” represents a temperature sensor output. As temperature measurement starts after inserting the probe  1  into an outer ear, an infrared radiation quantity from a tympanum is detected by the infrared radiation sensor  3  and internal temperature also is detected by the temperature sensor  6 , which are applied to CPU  5 . The probe cover detector  9  detects the presence or absence of the probe cover  2 , and the data representing the presence or absence is applied to the CPU  5 . In accordance with the presence or absence of the probe cover, the CPU  5  chooses K=k 1  when the cover exists, and K=k 2  when the cover does not exist to compute out Tx=k×Ts+Ta, thereby performing correct measurement viewing an infrared radiation quantity according to the presence or absence of the probe cover (k 1  and k 2  are values corresponding to infrared radiation transmission quantities).  
         [0025]    [0025]FIG. 3 shows a flow chart showing a main routine in an operation of the ear type clinical thermometer of this embodiment. The CPU  5  of the thermometer takes data of an infrared radiation quantity (step ST 1 ), judges if the measurement is started or a measurement switch is turned ON (step ST 2 ). When the measurement is started, the infrared radiation quantity Ts is measured by the infrared radiation sensor  3 , and the internal temperature Ta is measured by the temperature sensor  6  (step ST 3 ). Based on the taken data of the infrared radiation transmission quantity, temperature compute method is determined (step ST 4 ), temperature is computed by the temperature compute method (step ST 5 ), the computation result is shown by the display  7  (step ST 6 ), and the measurement is finished. There may be proposed several methods as described later to obtain the data of the above-described infrared radiation transmission quantity.  
         [0026]    The ear type clinical thermometer shown in FIG. 2 is provided with the probe cover detector  9 , wherein the presence or absence of the detected probe cover becomes a value or data corresponding to the infrared radiation quantity. Accordingly, in the clinical thermometer in this embodiment, the process in the step ST 1  is provided to detect the presence or absence of the mount by a probe cover (step ST 11 ), to judge if any probe cover exists (step ST 12 ), to regard the infrared radiation quantity on the presence of a probe cover as a transmission quantity when a probe cover exists (step ST 13 ) and the infrared radiation quantity on the absence of any probe cover as a transmission quantity when no probe cover exists (step ST 14 ) to be returned, as shown by the flow chart of a subroutine shown in FIG. 4. In the step ST 4 , an expression Tx=k 1 ×Ts+Ta is chosen when the probe cover exists, and an expression Tx=k 2 ×Ts+Ta is chosen when no probe cover exists.  
         [0027]    As a modification of the ear type clinical thermometer of this embodiment, the probe cover detector  9  may be replaced by an infrared radiation device  10  which radiates a known infrared radiation quantity to be received by a radiation thermometer  1  to obtain infrared radiation transmission data as shown in FIG. 5. The radiation  1  may employ the circuit diagram of FIG. 1. As shown by flow chart of a subroutine in FIG. 6, the radiation thermometer  1  upon start of measurement (step ST 21 ) measures an infrared quantity of the infrared radiation device  10  with known infrared radiation quantity by an infrared radiation sensor  3  (step ST 22 ), subsequently measures by the infrared radiation sensor  3  an infrared radiation quantity of an object to be measured for computing by an expression of (infrared transmission quantity)=(measured radiation quantity)/(known radiation quantity) (step ST 23 ).  
         [0028]    As another modification of the ear type clinical thermometer, the data of an infrared radiation transmission quantity may be entered by a ten-key. In a subroutine of the modified clinical thermometer shown in FIG. 7, upon entry of the key, the entry of input is confirmed (step ST 31 ), and the entered transmission quantity is accepted as an infrared radiation transmission quantity (step ST 32 ) for use of controlling the computation expression or decision of constants.  
         [0029]    As still another modification of the ear type clinical thermometer, a plural kinds of infrared radiation transmission quantities of probe covers having different transmission quantities are set in CPU  5  beforehand, and an infrared radiation transmission quantity is selectively entered by a switch operation. As shown by a subroutine in FIG. 8, a selection switch is read (step ST 41 ), it is identified which switch is selected (step ST 42 ). If a switch  1  is chosen, a transmission quantity corresponding to selected value  1  is regarded as the infrared radiation transmission quantity (step ST 43 ). If a switch  2  is chosen, a transmission quantity corresponding to selected value  2  is regarded as the infrared radiation transmission quantity (step ST 44 ). If a switch  3  is chosen, a transmission quantity corresponding to selected value  3  is regarded as the infrared radiation transmission quantity (step ST 45 ). Thus obtained respective infrared radiation transmission quantities may be used for controlling a computation expression, that is, decision of constants.  
         [0030]    In FIGS. 9 and 10, there are shown schematic views of a probe  1  and a probe cover  2  of an ear type clinical thermometer as still another modification of the preferred embodiment of this invention. This modified thermometer is designed to employ a plurality of probe covers  2  having different infrared radiation transmission lights. Each probe cover  2  at a flange  2   b  thereof is provided with three reading holes  2   a,  wherein each kind is represented by bit codes from 000 to 111 in which “0” represents a through hole, and “1” represents no hole. Buttons  11   a  of button switches  11  are exposed from a step  1   b  of the probe  1  of the main body confronting the reading holes  2   a  of the probe cover  2 . As the probe cover  2  is mounted on the probe  1 , the button  11   a  is not depressed and remains to be OFF in case the reading hole  2   a  is through hole as shown in FIG. 10 at (a), but is depressed and turned to ON in case the reading hole  2   a  is closed or does not exist as shown in FIG. 10 at (b). Thus, the kind of each probe cover  2  may be identified by the main body of the thermometer.  
         [0031]    [0031]FIG. 11 shows a subroutine of this modified thermometer. First, the code of a probe cover is read (step ST 51 ), and it is judged which kind is designated by the read code (set ST 52 ). As a result of the judgement, if it is code  1  (001), the transmission quantity corresponding to the code  1  is regarded as infrared radiation quantity (step ST 53 ). If it is code  2  (010), the transmission quantity corresponding to the code  2  is regarded as infrared radiation quantity (step ST 54 ). If it is code  3  (011), the transmission quantity corresponding to the code  3  is regarded as infrared radiation quantity (step ST 55 ). The computation expression is controlled according to the respectively obtained infrared radiation transmission rays.  
         [0032]    In FIG. 12, there is shown a flow chart of an operation in still another modification of the ear clinical thermometer. As data of infrared radiation transmission quantity is taken (step ST 61 ), it is inquired if the quantity is lower than a predetermined lower limit (step ST 62 ). If it is larger than the lower limit, it is inquired if the quantity is larger than a predetermined upper limit (step ST 63 ). When NO response is made, that is, the infrared radiation transmission quantity is between the upper limit and the lower limit, the sequence waits the manipulation of a measurement start switch (step ST 64 ), and the measurement starts to obtain an infrared radiation quantity Ts and an internal temperature Ta (step ST 65 ), decides a temperature compute method from the infrared radiation transmission quantity (step ST 66 ), computes out a temperature based on the detected infrared radiation quantity Ts and internal temperature Ta (step ST 67 ), and indicates a result of the measurement (step ST 68 ). When the response from step ST 62  or ST 63  is YES, viz., the infrared radiation transmission quantity is lower than the predetermined lower limit or larger than the predetermined upper limit, the sequence ends without any measurement operation.  
         [0033]    [0033]FIG. 13 shows a flow chart of an operation of still another modification of the ear type clinical thermometer of FIG. 12, in which the sequence (steps from ST 71  to ST 78 ) when the infrared radiation transmission quantity is between predetermined upper limit and lower limit is the same as that of FIG. 12. In this modified thermometer, if the infrared radiation transmission quantity is lower than the predetermined lower limit or larger than the predetermined upper limit, a measurement failure is displayed (step ST 79 ).  
         [0034]    [0034]FIG. 14 shows a flow chart of an operation of still another modification of the ear type clinical thermometer of FIG. 12, in which the sequence (steps from ST 81  to ST 88 ) when the infrared radiation transmission quantity is between predetermined upper limit and lower limit is the same as that of FIG. 12. In this modified thermometer, if the infrared radiation transmission quantity is lower than the predetermined lower limit or larger than the predetermined upper limit, it is displayed that the infrared radiation transmission quantity is out-of-range (step ST 89 ). In this modification, the measurement is executed as the measurement start switch is turned ON after out-of-range is displayed (steps ST 84  to ST 88 ).  
         [0035]    Thus, according to the above-mentioned embodiments and modifications, an infrared radiation transmission quantity of a probe is detected and a computation expression for temperature is chosen according to the detected infrared radiation transmission quantity, it may be avoided that an anomalous value is displayed when any probe cover is not mounted. Correct temperature such as body temperature may be measured irrelevant to the presence or absence of a probe cover.  
         [0036]    Though foregoing embodiments have been applied to ear type clinical thermometers, this invention may be widely applied to other thermometers. Having described embodiments of this invention, it will now be apparent to those skilled in the art that many changes may be made without departing from the inventive concepts. It is felt, therefore, that the invention should not be restricted to its disclosed embodiments, but rather should be limited only by the spirit and scope of the appended claims.