Abstract:
An electronic thermometer that reduces patient exposure to all sources of cross-contamination, aids in infection control, and provides a clean, uncontaminated, readily accessible source of probe covers. A probe assembly for an electronic thermometer, which does not require expensive calibration procedures during manufacturing and allows the use of inexpensive thermisters. A memory component such as an EEPROM integrated circuit stores calibration information and identifying information in each particular probe assembly which improves performance and reduces manufacturing costs.

Description:
RELATED APPLICATIONS  
       [0001]    This application claims priority to U.S. Provisional Patent Application Ser. No. 60/301,395, filed Jun. 27, 2001, the entire contents of which is hereby incorporated herein by reference. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    This invention relates to electronic thermometers, in particular, to electronic thermometers having interchangeable or removable temperature probes.  
         BACKGROUND OF THE INVENTION  
         [0003]    Electronic thermometers have been widely used for quick and accurate measurements of body temperature. A temperature sensing probe is inserted orally, rectally, or in an axillary (under the arm) position to measure a patient&#39;s temperature. The temperature sensitive probe is connected to thermal circuitry in a temperature calculating unit by an electrical cable. The temperature sensitive probe generates a signal. This signal passes through the electric cable to the temperature calculating unit, where the signal is converted into an equivalent temperature reading. The temperature calculating unit has a digital display which shows the calculated temperature reading.  
           [0004]    Before each measurement, a disposable plastic probe cover is placed over the temperature probe. The probe cover is then disposed after each temperature reading and a new probe cover is used for each subsequent measurement. When not in use, the temperature sensitive probe is stored in a housing, well or recess associated with the temperature calculating unit to minimize probe damage and probe contamination.  
           [0005]    In typical use, prior art electronic thermometers are susceptible to at least three major sources of contamination. First, these thermometers employ the same temperature sensitive probes for oral, rectal and axillary temperature measurements. Even though disposable plastic probe covers are used for each measurement, cross-contamination may still result from use of the same probe. Therefore, rectal or axillary contaminants on the probe may be passed orally to the same and/or other patients.  
           [0006]    The second source of contamination involves the probe storage chamber. Probes are stored in a single housing recess connected to the temperature calculating unit. This recess, once contaminated, may spread contamination to other probes as they may be interchangeably stored in the same recess. Over time, the storage chamber may also collect debris and contamination from the storage of multiple probes. Again, contaminants on the probe from rectal or axillary use may be passed orally to the same and/or other patients.  
           [0007]    The third source of contamination relates to the disposable probe covers. Each time a patient&#39;s temperature is measured, the probe is inserted into a box of unused disposable probe covers. The temperature probes of the prior art share a common source of probe covers. Hence, probes used for taking rectal, oral and axillary temperatures are repeatedly inserted into the same source of probe covers. The probe, then, once contaminated, may spread contamination to other unused probe covers. Contaminants deposited on the unused probe cover may then be passed on to the same patient and/or other patients.  
           [0008]    Since electronic thermometers are used for oral, axillary, and rectal temperature measurements, universal color codes have been adopted by hospitals, using red probes for rectal, temperature measurements and blue probes for oral and axillary temperature measurements. This color coding system makes it very easy for the healthcare practitioner to use the proper probe for each temperature reading, reducing the potential for cross-contamination.  
           [0009]    The use of a blue probe for oral and axillary temperature measurements and a red probe for rectal temperature measurements reduces the first source of contamination. Separating probe use in this manner also improves patient perception issues related to the health practitioners using the same probe for all types of temperature measurements. Such practice, however, requires two thermometer units to be available at each location if the probes are not interchangeable. Maintaining two units at each location has been considered an inefficient and costly measure. Such a practice also makes the practitioner susceptible to using the most convenient, yet inappropriate, unit.  
           [0010]    Some have developed thermometers with detachable probe units. U.S. Pat. No. 4,008,614, assigned to Johnson &amp; Johnson, New Brunswick, N.J., discloses an electronic thermometer unit usable with an oral temperature probe permanently attached to an oral isolation chamber. Similarly, there is a rectal probe permanently attached to a rectal isolation chamber. Connecting the probe and isolation chamber together as one unit thus precludes the inadvertent use of a probe with the wrong isolation chamber.  
           [0011]    Similarly, U.S. Pat. No. 4,619,271, assigned to Cheesebrough-Pond&#39;s, Inc., discloses an independent replaceable probe unit including a probe member and a probe chamber for holding the probe member, which can be easily removed and replaced together as a unit. The probe, cable and isolation chamber are all the same color. The permanent connection assures that the health practitioner stores the probe in the proper isolation chamber, thus reducing the risk of contamination leading to infection. A significant limitation of each of these approaches is that, even though the probe is permanently attached to an isolation chamber, both the oral and rectal probe units will be repeatedly and interchangeably inserted into the same box or boxes of probe covers, still exposing the probe to possible contamination.  
           [0012]    U.S. Pat. No. 4,572,365, assigned to Cheesebrough-Pond&#39;s Inc., discloses an improved probe cover holding and dispensing arrangement, the objective of which is to provide convenient access to clean probe covers. An electronic thermometer housing contains a chamber for receiving a canon of probe covers. Once the canon is inserted and secured within the housing, an aperture in the thermometer housing, normally closed by a sliding cover, provides access to the inserted carton of probe covers. In this arrangement, however, the probe and isolation unit may be interchanged between oral and rectal without changing the cartridge of probe covers. Both oral and rectal probe units share access to the same source of probe covers, providing a source of cross-contamination.  
           [0013]    U.S. Pat. No. 4,260,058 to Seymour et al. discloses an arrangement of mounting a holder on top of the thermometer device to receive a cartridge of probe covers. However, in this approach, probe covers are still stored with the temperature calculating unit. The disclosed arrangement does not require a dedicated probe and isolation chamber. This again may allow both oral and rectal probes access to a shared source of probe covers, providing a source of contamination.  
           [0014]    Each of these prior art approaches fail to address the exposure to contamination as each temperature sensitive probe, oral or rectal, is repeatedly inserted into the same box or boxes of probe covers. In each approach, the same source of probe covers is used whether the covers are stored in connection with the temperature calculating unit or separate from the thermometer altogether.  
           [0015]    Co-pending application entitled “Probe Tip Thermal Isolation and Fast Prediction Algorithm,” Application Ser. No. [not yet assigned] filed on Jun. 27, 2001 and incorporated herein by reference in its entirety discloses an electronic thermometer that reduces all three major sources of contamination and cross-contamination by eliminating the use of the same probe for oral, auxiliary and rectal temperature measurement, the use of the same storage chamber for each type of probe, and the use of the same supply of probe covers for each type of probe. The co-pending application discloses a removable module capable of receiving and storing both a temperature sensitive probe and a clean, uncontaminated supply of disposable probe covers. The removable module includes an isolation chamber that prevents the storage of the temperature sensitive probe with a probe cover remaining on the probe. The removable module also allows the practitioner to readily view a supply of probe covers through a transparent module housing without disassembling or physically contacting the removable module. A module housing aids in infection control by being easily cleaned or inexpensively replaced. A patient&#39;s exposure to all of the common sources of contamination encountered in the use of electronic thermometers is reduced by isolating the storage of the temperature sensitive probe and the disposable probe covers used for oral, auxiliary and rectal temperature measurement into dedicated units or modules.  
           [0016]    At least two types of removable modules are interchangeably operable with one temperature-calculating unit. The removable module is comprised of a probe assembly and a module housing. The module housing includes two chambers, one to store the probe and one to store a fresh supply of probe covers. Each of the module housing and probe assemblies are color coded according to the standard convention of red for rectal temperature measurement and blue for oral and auxiliary temperature measurements.  
           [0017]    Electronic thermometers as disclosed in the referenced co-pending application and electronic thermometers disclosed in the prior art typically employ temperature sensor elements in the probe such as thermisters. The thermisters and thermister circuits must be calibrated during manufacturing to compensate for component variation between thermisters and thermister circuits. For example, thermisters output a particular resistance value as a function of temperature. The resistance value is interpreted by the electronic components of the electronic thermometer as a temperature reading, or as an indication of a predicted temperature reading. If the thermister resistance has excessive variation or deviates from the nominal resistance at a particular temperature then, a compensation resistor must be installed during manufacturing.  
           [0018]    The calibration procedure is costly because it is labor intensive. During the calibration procedure, the resistance at the thermister must be measured at a controlled temperature and compensation resistors must be installed. Then, the resistance must be re-measured at a controlled temperature to assure that the calibration was successful. Expensive glass bulb thermisters having small component to component variation are used in typical electronic thermometer probes. These expensive thermistors also have a high thermal mass which increases the response time of the thermometer.  
           [0019]    Calibration by using compensation resistors requires temperature probes to be calibrated at a single reference temperature. Single point calibration causes relatively high linearity errors in temperature calculations resulting in decreased accuracy.  
           [0020]    The high costs associated with probe/sensor calibration and use of tight tolerance thermistors has made the use of multiple thermistors impractical in most probe applications. Some more accurate temperature calculation algorithms require input from more than one thermistor. Component costs have thereby rendered impractical the use of these more accurate temperature calculation algorithms.  
           [0021]    Although color coding and other identifying features has made probe units identifiable to users, interchangeable probe units of different types are not typically identifiable by the electronic hardware. This limits the ability of the temperature calculation components to adapt to variations between the probe unit types.  
         SUMMARY OF THE INVENTION  
         [0022]    The present invention reduces patient exposure to all sources of cross-contamination, aids in infection control, and provides a clean, uncontaminated, readily accessible source of probe covers. Embodiments of the present invention feature a probe assembly for an electronic thermometer, which does not require expensive calibration procedures during manufacturing and allows the use of inexpensive thermisters. A memory component such as an EEPROM stores calibration information and identifying information in the probe assembly.  
           [0023]    The present disclosure provides various embodiments which locate the memory component proximately with electrical connecting components where the probe assembly is electrically mated to the thermometer base unit. A circuit board including the memory component is embedded in the strain relief portion of the probe cable by insert molding or encapsulation wherein only the mating portions of the connector are exposed. When the temperature probe assembly is electrically mated to the thermometer base unit, the memory component is in electrical communication with the electronics of the base unit.  
           [0024]    Calibration information such as the resistance of the probe thermisters at corresponding calibration temperatures and probe identification data, i.e., serial numbers or probe type identifiers, is stored in the embedded memory component in the probe assembly. The electronic components of the base unit can read data from the memory component and compensate for variation in the probe thermisters according to the stored calibration information. The additional identifying information can be used by the thermometer base electronics to perform any number of functions. Such functions could include the use of separate algorithms for calculating a predicted temperature depending on the type of probe used.  
           [0025]    The invention of the present disclosure is particularly useful in electronic thermometers having interchangeable probe assemblies. Features of the invention include instant automatic identification of a temperature probe in a removable module. Effective interchangeability of different types of removable module-based temperature probes or different probes of the same type is featured without requiring labor intensive hardware modification.  
           [0026]    The invention further features improved performance and accuracy over prior art electronic thermometers. Embodiments of the invention feature more than one temperature sensor in a temperature probe for improved accuracy.  
           [0027]    The invention also features storage of all calibration parameters of the temperature sensors including calibration data for at least two different reference temperatures. This feature of the invention reduces linearity errors and improves a regression process used in the temperature calculation algorithm.  
           [0028]    The invention further features the use of a low cost, low thermal mass thermistor chip having a wide tolerance. This feature of the invention improves the thermal time constant and the overall response time of the thermometer as compared to conventional electronic thermometers which require tighter tolerance bulky glass bead type thermistors.  
           [0029]    Further features of the invention include the reduction or elimination of calibration costs during manufacturing of temperature probe. Manufacturing costs are further reduced by mounting the memory component on the same small circuit board that acts as an interface between the probe cable conductors and their connector pins. Embodiments of the invention feature encapsulation of the memory components in a strain relief portion of the probe cable. Such encapsulation provides protection against fluid incursion into the electronic components and probe cable. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0030]    The foregoing and other features and advantages of the present invention will be more fully understood from the following detailed description of the illustrative embodiments, taken in conjunction with the accompanying drawings in which:  
         [0031]    [0031]FIG. 1 is an illustration of an electronic thermometer according to at least one embodiment of the present invention;  
         [0032]    [0032]FIG. 2 is an illustration of a temperature calculation unit according to at least one embodiment of the invention;  
         [0033]    [0033]FIG. 3A is a rear view of a removable module according to at least one embodiment of the present invention;  
         [0034]    [0034]FIG. 3B is a front view of a removable module according to at least one embodiment of the present invention;  
         [0035]    [0035]FIG. 4 is an illustration of a removable module mating to a temperature calculating unit according to at least one embodiment of the present invention;  
         [0036]    [0036]FIG. 5A is an illustration of a connector assembly according to at least one embodiment of the present invention;  
         [0037]    [0037]FIG. 5B is an illustration of a connector assembly according to another embodiment of the present invention;  
         [0038]    [0038]FIG. 6A is an illustration of a connector housing/PCB sub-assembly according to at least one embodiment of the invention;  
         [0039]    [0039]FIG. 6B is an illustration of a connector housing/PCB sub-assembly according to another embodiment of the invention;  
         [0040]    [0040]FIG. 7 is an illustration of a PCB according to at least one embodiment of the present invention;  
         [0041]    [0041]FIG. 8 is an illustration of a complete probe assembly (first connector component, electrical cable and probe) according to at least one embodiment of the invention;  
         [0042]    [0042]FIG. 9A is a front and top orthographic view of a second connector component according to at least one embodiment of the present invention;  
         [0043]    [0043]FIG. 9B is a cross-sectional view of a terminal pin cavity in a second connector component according to at least one embodiment of the present invention; and  
         [0044]    [0044]FIG. 9C is an illustration of a second connector component according to an embodiment of the invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0045]    Reference is now made to the embodiments illustrated in FIGS.  1 - 9 C wherein like numerals are used to designate like parts throughout. In cases where parts have similar form and function, similar numerals may be used for ease in interpretative cross referencing.  
         [0046]    Referring to FIG. 1, a thermometer according to the present invention is shown. The thermometer includes a temperature calculating unit and a removable module that is mated and secured to the temperature calculating unit. When the removable module is secured to the temperature calculating unit, a connector assembly component and a mating header assembly component are properly aligned and together form an electrical connection. This electrical connection allows a signal detected by a temperature probe to be transmitted from the removable module to the temperature calculating unit. Once received, the temperature calculating unit converts the signal to a temperature reading. The temperature reading is observed through a display window.  
         [0047]    As shown at FIG. 2, there is shown a temperature calculating unit  200  according to at least one embodiment of the present invention. Fastening means are provided to secure a removable module to the temperature calculating unit. In an illustrative embodiment, a pair of rails  270 ,  272  are provided as fastening or alignment means to engage mating features in the removable module. Additional alignment means and securing means may be provided on the temperature calculating unit to facilitate mating with the removable module. For example, securing means  242 ,  244  includes tabs protruding from a battery compartment cover  246  and engage mating features in the removable module. The battery compartment cover  246  may be made from an elastomeric material so that the securing means  242 ,  244  are flexible and making cover  246  easily removable from the top of the battery compartment. The battery cover  246  fits within an orifice  247  in the mounting surface  240 . A battery  400  is situated within the battery compartment. In an illustrative embodiment, the top of the battery compartment coincides with a mounting surface  240  which abuts the bottom surface of the removable module when the removable module is installed to the temperature unit. The mounting surface  240  also provides a location for trigger devices  322  which may be located in recesses  320  of the mounting surface  240 . The trigger devices  322  can be used to distinguish the particular type of removable module that is installed to the temperature calculation unit by providing strikers or protrusions at particular positions on the bottom surface of the removable module which identify the particular type of removable module being used. A slot  260  is provided in the back surface  262  of the temperature calculation unit  200 . The slot  260  engages the outer walls of an isolation chamber which protrudes from a front surface of the removable module. In the illustrative embodiment, the slot is shaped to provide a lead-in feature which assists in guiding the removable module while it is slidingly mated to the temperature calculation unit  200 . A button  245  mounted in the slot is linked to the electronics of the temperature calculating unit  200 . When depressed, the button  245  causes the temperature calculating unit  200  to turn off.  
         [0048]    Now referring to FIG. 3A, a rear view of a removable module according to at least one embodiment of the present invention is shown. The removable module  100  includes a storage chamber  182  for storing disposable probe covers  184  which are packaged in cartons  186 . The removable module  100  further includes a temperature sensitive probe assembly  160  and module housing  180 . The probe assembly  160  comprises a temperature sensitive probe  161 , electrical cable  162  and a first connector component  120 . The temperature sensitive probe  161  is attached to electrical cable  162  (FIG. 8), which is connected at its opposite end to the first connector component  120 . The probe assembly  160  locks into module housing  180  at a housing orifice  122 . The probe assembly  160  may be fixedly attached or unlocked and detached from the module housing  180  for replacement if needed.  
         [0049]    The module housing  180  contains an isolation chamber  140  and a storage chamber  182 . As best shown in FIG. 3B, the isolation chamber  140  is positioned in the center of the back side wall of the module housing  180 . When not in use, the probe  161  is inserted into the isolation chamber  140 . When the removable module  100  is in its secured position with the temperature calculating unit  200 , the probe  161  rests between the temperature calculating unit  200  and the storage chamber  182 , providing additional physical protection to the probe  161 . For the purposes of the present disclosure, the isolation chamber  140  maybe located anywhere within the module housing  180 . The inside diameter of the isolation chamber  140  corresponds to the outside diameter of the probe  161 , such that, the probe  161  cannot be inserted into the isolation chamber  140  with the probe cover  184  still attached to the probe  161 .  
         [0050]    Since the probe  161  and the isolation chamber  140  are both components of the same removable module  100 , the probe  161  can be stored in only one isolation chamber  140 , thus reducing the possibility of cross-contamination and spread of infection. If there is concern that the isolation chamber  140  has in any way been contaminated, the entire removable module  100  may be removed for cleaning. Alternatively, the module housing  180  may be inexpensively replaced.  
         [0051]    At the bottom of the isolation chamber  140 , there is a switch actuating device such as a paddle indicator  145  (FIG. 3B) for triggering an automatic on/off mechanism. When the probe  161  is inserted into the isolation chamber  140  during periods of nonuse, the probe  161  pushes the paddle indicator  145  and bends it into contact with the button  145  on the temperature calculating unit  200  (FIG. 2). The button  245  is linked to the electronics of the temperature calculating unit  200 . When actuated, the button  245  causes the temperature calculating unit  200  to turn off. Upon withdrawal of the probe  161  from the isolation chamber  140 , the paddle indicator releases. This causes the temperature calculating unit  200  to turn on and prepare for a temperature measurement. This automatic on/off mechanism conserves the battery life of the temperature calculating unit  200 . The paddle indicator  145  may also be used as a reset button, indicating when a new temperature reading may be taken. If the temperature calculating unit  200  has a tied shut off mechanism, the paddle indicator  145  may be used to reactivate the temperature calculating unit  200 . This may be accomplished by inserting and removing the probe  161  from the isolation chamber  141 , thus triggering the paddle indicator  145  and turning on the temperature calculating unit  200 . The paddle indicator  145  may be any type of mechanical, electrical, magnetic or optical switch capable of differentiating between the presence and absence of the probe  161  in the isolation chamber  140 .  
         [0052]    Referring again to FIG. 3A, the module housing  180  also contains a storage chamber  182 . A carton  186  of disposable probe covers containing disposal probe covers  184  fits snuggly into the storage chamber  182 . The carton  186  may be perforated with tabs such that the practitioner can pull the perforated tear-away tab and expose several probe covers  184 .  
         [0053]    In an alternate embodiment, the storage chamber  182  may contain means to prevent the box of disposable covers from being removed and used interchangeably with other removable modules  100 . For example, the storage chamber  182  may contain small projections  189  that puncture the sides of the carton of probe covers  186  such that attempts to remove the carton would cause the carton to tear. In another embodiment, the carton  186  may have a perforated bottom that tears. Therefore, if the carton is removed the bottom would tear out. The practitioner would then need to insert a fresh carton  186  of probe covers  184  into the storage chamber  182 . This feature deters a practitioner from switching the probe covers from one removable module to another, increasing the potential for cross-contamination. The entire removable module  100 , including the probe  161 , the electrical cable  162 , the first connector component  120  and the module housing  180  is color coded according to the standard convention of blue for oral and axillary measurements and red for rectal measurements.  
         [0054]    In addition to being color coded, the module housing  180  of the present embodiment is transparent or translucent. Such a transparent housing allows the practitioner to conveniently view and count the number of probe covers  184  remaining in the carton  186  at any given time. Transparency of the module housing  180  also allows the practitioner to read the information on the carton  186 , including instructions for use, warnings and reordering information. The completely transparent module housing  180  is one example according to the present disclosure.  
         [0055]    The module housing  180  may have, for example, a single transparent portion, such as any one side, top, front or back panel. When the carton  186  (FIGS. 3B and 4) contains a top perforated tab  187 , the contents may be viewed through a transparent top. Similarly, when the carton  186  contains a side panel perforation, the contents may be viewed through a transparent back panel on the module housing  180 . In these situations, it is necessary only to have one transparent or translucent top portion or side panel to the module housing  180  for viewing and counting. The module housing  180  includes fastening means to aid in mounting the removable module  100  to the backside of the temperature calculating unit  200 . As best shown in FIGS. 2 and 3B, the fastening means used in the current embodiment are tracks  170  and  172 , which are molded, recesses in module housing  180 . These tracks  170  and  172  receive rails  270  and  272  on the temperature calculating unit  200 . In addition, the module housing  180  contains securing means  142  and  144 , which are also molded recesses in the module housing  180 . Recesses  142  and  144  receive securing means  242  and  244  located on a mounting surface  240  of the temperature calculating unit  200 . Removable module  100  is attached to the temperature calculating unit  200  by first aligning the rails  270  and  272  with tracks  170  and  172  and securing means  142  and  144  with securing means  242  and  244 , then sliding the removable module  100  down on to the mounting surface  240  until a locking tab  166  snaps into place over the top edge of the temperature calculating unit  200 . It should be understood that fastening means, securing means and locking tabs, as defined by the present disclosure, could be any connection device or configuration of connection devices that serve to firmly secure the removable module  100  in position on the temperature calculating unit  200 .  
         [0056]    The temperature calculating unit  200  includes a second connector component  220  located on the side to which the removable module  100  is mounted. The second connector component  220  (FIG. 9) is wired to the thermometer circuitry within the temperature calculating unit  200 . When the removable module  100  is secured to the temperature calculating unit  200 , the first connector component  120  and second connector component  220  mate to form an electrical connection. The temperature calculating unit  200  receives the signal detected by the probe  161 , transmitted through the first  120  and second  220  connector components, and converts the signal into a temperature reading  280 . The resulting temperature reading  280  is observed through the display window  182 .  
         [0057]    The circuitry of temperature calculating unit  200  is powered by a battery  400 . The battery  400  is accessed through a cover  246  that fits into orifice  247  within mounting surface  240 . In the embodiment shown in FIG. 4, cover  246  is made from rubber to create a water tight seal, enabling the entire temperature calculating unit  200  to be submersed in water for cleaning. The cover  246  further comprises the securing means  242  and  244 . The cover  246  can be peeled away from the mounting surface  240  to expose and replace the battery  400 .  
         [0058]    In an alternate embodiment, for example, referring again to FIGS. 2 and 3B, the removable module  100  and the temperature calculating unit  200  may also include means to detect the type of removable module  100  secured to the temperature calculating unit  200 . Such means may include a two part switch which enables the temperature calculating unit  200  to sense the presence of an object connected to the mounting surface  240 .  
         [0059]    The temperature calculating unit  200  may have a plurality of recesses  320  on the mounting surface  240 , each recess  320  containing a trigger device  322 . There may be a plurality of corresponding protrusions, such as posts  310  (FIG. 3B) on the removable module  100 . When the removable module  100  is connected to the temperature calculating unit  200 , the posts  310  fit into the recesses  320 , triggering the switches  322 . The switches  322  are then sensed by the temperature calculating unit  200 . Each type of removable module  100  may have a different number or location of posts  310 . For example, an oral module  100  may have one post  310  which corresponds to switch  322  within recess  320 , while the rectal module may have no posts  310  to trigger switches  322 .  
         [0060]    Upon connection of the module  100  to the temperature calculating unit  200 , triggering of the switches  322  will result in two alternative signals. These two part switches then enable temperature calculating unit  200  to detect the type of movable module attached. Once the module type is detected, temperature calculating unit  200  will calibrate in order to make the appropriate temperature measurements. Providing two recesses on the mounting surface  240  gives the temperature calculating unit  200  a capability of differentiating four different types of modules and operating accordingly. It should be understood, however, that the two part switches described may consist of any known electrical, mechanical, magnetic or optical switch.  
         [0061]    In at least one embodiment, the first  120  and second  220  connector components may carry encoded information related to probe identity and associated calibration parameters. Such encoded information enables temperature calculating unit  200  to detect the type of removable module  100  attached. As shown on FIGS.  5 A- 6 B, spring loaded posts  121  on the first connector component  120  may be used to engage contact pads  221  on second connector component  220  (FIGS. 2, 9A,  9 B and  9 C). It is contemplated that the first  120  and the second  220  connector components may be any mechanical, electrical, magnetic or optical contacts such that when the two connection components are in proximity, a signal can pass from the removable module  100  to the temperature calculating unit  200 . Thus, when removable module  100  is connected to temperature calculating unit  200 , temperature calculating unit  200  reads the encoded information carried by the attached removable module  100  and automatically sets the corresponding operating conditions.  
         [0062]    Now referring back to FIGS.  1 - 4 , upon the connection of an oral/axillary type removable module  100  to the temperature calculating unit  200 , the temperature calculating unit  200  reads the identity of the oral/axillary type probe  161 . Whereupon, the second connector component  220  which is connected to the electronic circuitry of the temperature calculating unit  200 , causes the display of an oral/axillary icon  283  located within window  282 . This icon  283  indicates to the practitioner, that the thermometer  10  is ready to operate in the oral/axillary mode. Similarly, when a rectal type removable module  100  is connected to the temperature calculating unit  200 , the temperature calculating unit  200  reads the identity of the rectal type removable module  100  and displays a corresponding icon  283  within window  282 , indicating that the thermometer  10  is ready to operate in the rectal mode.  
         [0063]    The operation of the thermometer  10  according to the present disclosure will now be described with reference to FIGS.  1 - 4 . When a temperature measurement is to be taken, the practitioner selects the appropriate module and mounts the removable module  100  on to the temperature calculating unit  200 . By way of example, if an oral temperature measurement is desired, a blue removable module  100  is secured to temperature calculating unit  200  by aligning the rails  270  and  272  of the temperature calculating unit  200  and the tracks  170  and  172  of the removable module  100 . As best shown in FIG. 4, once the rails  270  and  272  are aligned, the practitioner slides the removable module  100  downward such that the bottom of the module  100  rests on mounting surface  240 . In this sliding action, the securing means  242  and  244  is mated with recesses  142  and  144  until locking tab  166  snaps into place. When secured in this manner, first connector component  120  and second connector component  220  form the connection to activate the thermometer  10 .  
         [0064]    The temperature sensitive probe  161  is removed from the isolation chamber  140 , activating the thermometer to a ready mode. The probe  161  is then inserted into a probe cover  184  within storage chamber  182 . Insertion of the probe  161  into the probe cover  184  creates a snap fit between the probe  161  and probe cover  184 . The probe  161  is withdrawn from the carton  186  with cover  184  attached. The practitioner pushes a button  284  (FIG. 1) to select the oral or axillary mode. A short beep indicates that the thermometer  10  is ready to take a measurement. The probe  161  is inserted into the patient&#39;s mouth. When the measurement is complete a long beep is sounded and the final temperature reading  280  is displayed. Temperature reading  280  is observed through display window  282 . The probe  161  is then withdrawn from the patient&#39;s mouth and a probe button  168  is depressed to eject the probe cover  184  into an appropriate waste container. The probe  161  may then be inserted into another probe cover  184  in the carton  186  again if another reading is desired. Alternatively, the probe  161  is inserted back into the isolation chamber  140  for storage. The insertion of the probe  161  into the isolation chamber  140  switches the thermometer  10  to standby mode.  
         [0065]    If a rectal temperature measurement is next desired, it is necessary only to change the removable module  100 . To remove the oral type removable module  100 , the practitioner first pulls back on a locking tab  166 . Once the locking tab  166  is released, the practitioner slides the oral type removable module  100  off of rails  270  and  272  to disengage it from the temperature calculating unit  200 . The rectal type removable module  100  is then secured to the temperature calculating unit  200  in the manner described above.  
         [0066]    As discussed above, the probe  161 , the isolation chamber  140  and the probe covers  184  are contained within one unit, i.e., the removable module  100 . This removable module  100  prevents the interchangeable use of the probe  161 , the isolation chamber  140  and probe covers  184 . Thus, the removable module  100  of the current disclosure reduces all major sources of contamination by preventing the commingling of the probe  161 , the isolation chamber  140  and the disposable probe covers  184 . At the same time, the thermometer unit  10  of the current disclosure remains cost effective since it requires only one temperature calculating unit  200  to use with all types of probes  161 .  
         [0067]    According to the present disclosure, the removable module  100  is instantly detectable and identifiable to the electronic components in the temperature calculation unit  200 . Referring to FIGS.  1 - 4 , illustrative embodiments of the thermometer  10  are shown. FIGS.  5 A- 9 C further show illustrative embodiments of the connector components according to the present invention. An electrically erasable programmable read only memory EEPROM Integrated Circuit (IC) Chip  410  is soldered onto a small printed circuit board (PCB)  400  (FIG. 7) and configured to the first connector component  120  of electrical cable  162  (FIG. 6A). At least part of the PCB  400  is overmolded and encapsulated. (FIGS. 5A and 5B).  
         [0068]    FIGS.  6 A- 6 B illustrate a partially assembled first connector component  120  including PCB  400  having an EEPROM IC  410  soldered thereon. FIG. 7 illustrates the PCB  400  and EEPROM Chip  410  prior to its assembly to the first connector component  120 . The first connector component  120  and strain relief  164  (FIGS. 5A and 5B) are coupled together prior to assembly to the removable module  100 . Spring loaded posts  121  provide electrical connectivity between the electrical cable  162  and contact pads  221  in the second connector component  220  of the temperature calculating unit  200  (FIG. 2). The second connector component  220  is in electrical communication with the electronic components of the temperature calculating unit  200 .  
         [0069]    The EEPROM Chip  410 , the PCB  400  and the electrical connections to the PCB  400  are protected from environmental factors by being encapsulated or over-molded. Such encapsulation renders these components water resistant and meets the Comite European de Normalisation-European Committee for Electrotechnical Standardization&#39;s (CEN) water resistance compliance requirement. The particular EEPROM Chip  410  used in thermometer  10  may include, for instance, a Parasite Power 256 Bit Single Wire Communicating 1-Wire EEPROM IC Chip such as the DS2430A model available from Dallas Semiconductor. The data sheet for the Dallas Semiconductor model DS2430A is incorporated herein by reference in its entirety.  
         [0070]    The data line of the EEPROM Chip  410  is directly connected to a single port pin of the thermometer microprocessor. The EEPROM Chip  410  does not require any separate power connections because it receives power from the data line. The particular DS2430A model EEPROM Chip  410  communicates with the microprocessor at up to 16.3K bits per second. It is contemplated that various microprocessor communication speeds are with the spirit of the present disclosure. Upon power up, the microprocessor automatically reads a unique, factory laser-programmed and validated 64 bit registration number to identify the probe  161 . The microprocessor then reads pre-stored 256 bit calibration and algorithm parameters which characterize the particular temperature probe in which the EEPROM Chip  410  is imbedded.  
         [0071]    In at least one embodiment of the invention, one end of the electrical cable  162  is attached to the temperature probe  161  (FIG. 8) and the other end of the electrical cable  162  is connected to the PCB  400  (FIGS. 5A, 5B,  6 A,  6 B,  7  and  8 ). The PCB  400  includes eight (8) conductive metal (e.g., gold) plated pads; five (5) of which are connected to five (5) conductors located within electrical cable  162 ; two (2) of which are connected to the EEPROM Chip  410 . It is hereby contemplated that the particular connections between the EEPROM Chip  410 , PCB  400  and electrical cable  162  may be varied dependent upon the particular integrated circuits, circuit boards, cables and electrical connections used. In one embodiment, the PCB  400  containing the EEPROM Chip  410  slides into the first connector component  120  (FIG. 6B) before it is overmolded. In an alternate embodiment, the portion of the PCB  400  containing the EEPROM Chip  410  and cable connections are sealed and overmolded together with the strain relief  164 . In either embodiment, the overmolded connector portion of the electrical cable  162  is permanently attached to the wall of the removable module (FIG. 3B). The first connector component  120  housing is designed so that it can be inserted and locked into a mating space in the removable module  100  so that the temperature probe  161  and electrical cable  162  becomes an integral part of the removable module  100 .  
         [0072]    Similarly, the second connector component  220  and its terminals pins or pads  221  are environmentally encapsulated so that there is no fluid penetration into the second connector component  220  and temperature calculation unit  200  case. The mating second connector component  220  (FIGS. 2, 9A,  9 B and  9 C) includes stamped metal terminal pins  221  which are inserted into the connector housing  225  and sealed. The backend of these terminal pins  221  are soldered onto a printed circuit board of the temperature calculation unit  200  during the assembly process of other components. The connector housing  225  of the second connector component  220  is aligned and installed into a cavity (not shown) behind the back surface  262  (FIG. 2) of the temperature calculation unit  200 , providing for a sealing arrangement between the back surface  262  of the temperature calculation unit  200 , and the second connector component  220  including the terminal pins  221  and the connector housing  225 . This sealing arrangement eliminates the possibility of any fluid ingression to the temperature calculating unit  200 .  
         [0073]    An exemplary embodiment of a second connector component  220  is illustrated in FIG. 9C. Grooves  223  on each side of the periphery of the second connector component  220  accepts and locks mating flanges  127  on the first connector component  120  (FIGS. 5B and 6B) to form an electrical connection when the removable module  100  (FIGS. 3A and 3B) is installed to the temperature calculating unit  200  (FIG. 2). The flanges  127  situated along the periphery of the first connector component  120  slide into the grooves  223  in the second connector component  220  when the removable module  100  is slidingly mated to the temperature calculating unit  200 . Engagement between the flanges  127  on the first connector component  120  and the grooves  223  of the second connector component  220  ensure that spring loaded posts  121  are held in secure electrical contact with contact pads  221 . Engagement between the flanges  127  on the first connector component  120  and the grooves  223  on the second connector component  220  also prevents fluid from reaching the contact area where it could potentially degrade the electrical contacts between the spring loaded posts  121  and the contact pads  221  or enter inside the temperature calculating unit  220 .  
         [0074]    The EEPROM Chip  410 , embedded in the first connector component  120 , holds all the necessary information and/or parameters that are required for an accurate two-point calibration of the thermistor sensors in each associated temperature probe  161  (FIG. 8). This information includes calibration related parameters such as thermistor resistor values at two different temperatures.  
         [0075]    The EEPROM Chip  410  also holds information necessary for identifying the probe and probe type. This information includes the probe identification information related to type of removable module (rectal, or oral/axillary), unique assembly part numbers, date codes, Cyclical Redundancy Check (CRC) and other manufacturing related data. In an illustrative embodiment using the EEPROM IC Chip model DS2430A available from Dallas Semiconductor, the identifying information includes a unique factory laser-programmed and validated 64 bit registration number.  
         [0076]    Although the memory component described herein is implemented illustratively in the form of an EEPROM Chip  410 , it is contemplated that the temperature probe adapter according to the present disclosure can be implemented by various circuit configurations and/or memory elements. In an alternate embodiment, a radio-frequency (RF) transmission technique, that is wireless communication, can also be used to communicate between the temperature calculating unit or any other calibration station with the detachable ISO-Chamber based temperature probe assembly. The probe cable  162  can have an embedded Read only (R) or Read/Write (R/W) RFID-radio frequency identification transponder tag or microchip. The on-the-chip EEPROM can be wirelessly read and written from the base unit, i.e., the temperature calculating unit or any other calibration station.  
         [0077]    Although the present disclosure is described herein with respect to illustrative embodiments thereof, it should be appreciated that the foregoing and various other changes, omissions or additions in the form and detail thereof may be made without departing from the spirit and scope of the disclosure. It is to be understood that the described embodiments of the disclosure are illustrative only, and that modifications thereof may occur to those skilled in the art. Accordingly, this disclosure is not to be regarded as limited to the embodiments disclosed, but is to be limited only as defined by the appended claims.