METHOD FOR OPERATING THE HEATING SYSTEM OF AN ENDOSCOPE, HEATING SYSTEM OF AN ENDOSCOPE, AND ENDOSCOPE SYSTEM

Abstract

A method for operating a heating system of an endoscope. The endoscope including a heating element and a temperature sensor in a distal region of the endoscope and a supply unit outside of the endoscope, the supply unit being connected to the heating element and the temperature sensor, wherein the supply unit activates and deactivates a power supply for the heating element on a basis of a temperature measurement value ascertained by means of the temperature sensor using two-state control, and a monitoring unit including a monitoring circuit which is powered by the power supply for the heating element. The method including: monitoring, with the monitoring circuit, the temperature sensor for a malfunction; and interrupting the power supply to the heating element if the malfunction of the temperature sensor is determined.

Claims

1. A method for operating a heating system of an endoscope, the endoscope comprising a heating element and a temperature sensor in a distal region of the endoscope and a supply unit outside of the endoscope, the supply unit being connected to the heating element and the temperature sensor, wherein the supply unit activates and deactivates a power supply for the heating element on a basis of a temperature measurement value ascertained by means of the temperature sensor using two-state control, and a monitoring unit comprising a monitoring circuit which is powered by the power supply for the heating element, the method comprising: monitoring, with the monitoring circuit, the temperature sensor for a malfunction; and interrupting the power supply to the heating element if the malfunction of the temperature sensor is determined.

2. The method according to claim 1, wherein the monitoring unit comprises a monitoring temperature sensor connected to the monitoring circuit, wherein the method comprises: checking, with the monitoring circuit, whether the one or more of the endoscope and the heating system were newly activated after a break of a predefined length sufficient for cooling the heating element to an ambient temperature, or if only the energizing of the heating element was interrupted while the endoscope and the heating system continued to be operated, where one or more of the endoscope and the heating system are determined to be newly activated, comparing, with the monitoring circuit, temperature measurements of the temperature sensor and the monitoring temperature sensor with one another; and where the temperature measurements deviate beyond a predefined tolerance range, determining a malfunction of the temperature sensor.

3. The method according to claim 1, wherein the method comprises: monitoring, in the monitoring circuit, successive temperature measurements of the temperature sensor for jumps; and where a predefined temperature increase threshold is determined determining a malfunction of the temperature sensor.

4. The method according to claim 1, wherein the method comprising: monitoring, in the monitoring circuit, in regular operation after activation of the power supply for the heating element, whether the temperature measurement of the temperature sensor does not fall below a predefined lower temperature threshold; and determining, in the monitoring circuit a malfunction of the temperature sensor if the temperature measurement falls below the predefined lower temperature threshold.

5. The method according to claim 1, wherein the method further comprising: storing, in the monitoring circuit, the determination of a malfunction of the temperature sensor in a non-volatile memory; and keeping the power supply to the heating element interrupted until the memory is purged.

6. The method according to claim 5, further comprising purging the memory on the basis of one of an external command or if a subsequent measurement does not confirm the malfunction.

7. The method according to claim 1, wherein the method comprises: detecting, at one or more of the supply unit and a central control unit that the power supply to the heating element has been interrupted by the monitoring circuit; and outputting a notification of the interruption.

8. A heating system of an endoscope, the heating system comprising: a heating element disposed in a distal region of the endoscope; a temperature sensor disposed in the distal region of the endoscope; a supply unit disposed outside of the endoscope, the supply unit being connected to the heating element and to the temperature sensor, wherein the supply unit is configured to activate and deactivate a power supply for the heating element on a basis of a temperature measurement value ascertained by the temperature sensor using a two-state control; and a monitoring unit disposed in the endoscope, the monitoring unit comprises a monitoring circuit powered by the power supply for the heating element; and wherein the monitoring circuit being signal-linked to the temperature sensor and configured to monitor the temperature measurements of the temperature sensor and to interrupt the power supply to the heating element if a malfunction of the temperature sensor is determined.

9. The heating system according to claim 8, wherein the monitoring unit is disposed in a proximal part of the endoscope.

10. The heating system according to claim 8, wherein the monitoring unit comprises a monitoring temperature sensor connected to the monitoring circuit.

11. The heating system according to claim 8, wherein the monitoring circuit comprises a time member for monitoring a time during which the monitoring circuit is not energized.

12. The heating system according to claim 11, wherein the time member is an analog time member.

13. The heating system according to claim 12, wherein the analog time member is a discharging RC member.

14. The heating system according to claim 8, wherein the monitoring circuit comprises first and second energy accumulators, wherein the first energy accumulator is chargeable via the power supply for the heating element and the second energy accumulator is chargeable via a conductor from the supply unit to the temperature sensor.

15. The heating system according to claim 8, wherein the monitoring circuit comprises a non-volatile memory for storing malfunctions of the temperature sensor.

16. An endoscope system comprising: an endoscope; and the heating system according to claim 8.

Description

BRIEF DESCRIPTION OF THE DRAWING

[0029] Further features will become evident from the description of the embodiments together with the claims and the attached drawing. Embodiments can fulfill individual features or a combination of several features.

[0030] The embodiments are described below, without restricting the general idea of the invention, based on exemplary embodiments in reference to the drawing, whereby we expressly refer to the drawing with regard to the disclosure of all details that are not explained in greater detail in the text.

[0031] FIG. 1 illustrates an endoscope system according to an embodiment.

[0032] FIG. 2 illustrates an embodiment of the monitoring circuit of FIG. 1.

[0033] FIG. 3 illustrates an embodiment of the time member of FIG. 2.

DETAILED DESCRIPTION

[0034] FIG. 1 schematically shows an endoscope system 10, which comprises an endoscope 30 and a central unit 20, which is configured for the supply and control of the endoscope 30. The central unit 20 comprises a supply unit 22, which is connected via two two-core conductors 26, 28 to a distal heating element 32 and a distal temperature sensor 34, such as a thermistor with a negative temperature coefficient. The heating element 32 can be a heating resistor. The connection is implemented via a coupling interface 24 in which the conductors 26, 28 in the endoscope are connected to external conductors that lead to the supply unit 22. The small numerals 2 below the slashes which cross the two conductors 26, 28 near the connecting lines to the reference signs symbolize the two-core nature of the two conductors 26, 28.

[0035] The elements described thus far form the traditional heating system of an endoscope the distal region of which is shown in FIG. 1 on the right. The heating element 32 and the temperature sensor 34 are located in the immediate vicinity of an entrance window (not shown) at the distal end of the endoscope shaft and ensure by heating this region to roughly a body temperature of a patient that the other window does not fog up when the window is introduced into a body cavity of the patient.

[0036] The supply unit 22 serves as a controller using a two-state control. For this purpose, it is connected as a constant current source to the temperature sensor 34 via the line 28 and is configured to carry out a temperature measurement via the measurement of the voltage dropping across the temperature sensor 34. Depending on the measured temperature or the measured voltage value corresponding to a temperature value, power to the heating element 32 via line 26 is turned on or off. When an upper threshold is reached, the power supply is deactivated and reactivated when the temperature has dropped to a lower threshold. This is a very simple control which is sufficient for setting the temperature for this purpose.

[0037] A monitoring unit 40 is added in the proximal region of the endoscope 30, the monitoring unit comprising a monitoring circuit 42 and a monitoring temperature sensor 44 in the exemplary embodiment shown in FIG. 1. The monitoring circuit 42 is connected to the power supply via the conductor 26, which serves as the power supply for the heating element 32. The monitoring circuit 42 is thus supplied with power parasitically and is thus only powered when the operation of the power supply 22 is in a state such that the heating element 32 is also intended to be energized. In the cooling phases, the monitoring circuit 42 is not energized either.

[0038] The monitoring circuit 42 is moreover connected to the conductor 28, which leads from the power supply 22 in its function as a constant current source to the temperature sensor 34. Thereby, the monitoring circuit 42 is able to measure the voltage drop across the temperature sensor 34 independently from the external unit and thus to monitor the functioning of the temperature sensor 34.

[0039] In the embodiment depicted in FIG. 1, the monitoring unit 40 moreover comprises a monitoring temperature sensor 44 that is connected to the monitoring circuit 42 such that the latter can perform a temperature measurement using the monitoring temperature sensor 44 so long as it is powered. This is the case for example after activation of the endoscope 30, which is already being heated immediately after activation in the distal region. Thus, it is possible to perform a so-called power-on detection during which the surroundings of the temperature sensor 34 and of the monitoring temperature sensor 44 have adapted to the ambient temperature and thus have the same temperature. The temperature measurement with the monitoring temperature sensor 44 is used in this case for verifying the temperature measurement by means of the temperature sensor 34 at room temperature.

[0040] Even after activation and during heating of the heating element 32, further monitoring can take place. To this end, successive measurements of the temperature by means of the temperature sensor 34 are performed by the monitoring circuit 42. For this purpose, the monitoring circuit 42 comprises memories for successive temperature measurement values or voltage measurement values, respectively, and a logic, that allow for a comparison of these measurement values and a comparison with thresholds for the maximum permissible differences. This makes it possible to detect jumps in the temperature curve of the temperature sensor 34.

[0041] Furthermore, a further monitoring can take place even after regular operation has been achieved, which is made more difficult by the fact that cooling phases occur regularly during regular operation during which neither the heating element 32 nor the monitoring circuit 42 is powered. In this case, the monitoring circuit 42 verifies when the power supply is reactivated whether it was merely a typical cooling phase in that, for example, it is determined that a slowly discharging time member (FIG. 2), for example an RC member, is only slightly discharged, or in that, by means of an energy accumulator (FIG. 2) of the monitoring circuit 42, which is charged via the conductor 28 to the continually operated temperature sensor 34, it is determined that such accumulator is still charged. Once it is ensured that the case is that of a reactivation after a cooling phase during regular operation, it is determined whether the temperature measured with the temperature sensor 34 is below the lower threshold for the control action or a threshold slightly below that. Such an event is the consequence of a malfunction of the temperature sensor 34.

[0042] Furthermore, the central unit 20 and/or optionally the supply unit 22 can be configured to detect if, despite current being supplied by the supply unit 22, the temperature does not change in the distal region of the endoscope. This is an indication that the monitoring circuit 42 has determined a malfunction of the temperature sensor 34 and is blocking the energizing of the heating element 32. If this is detected, a notification or a warning is output that a corresponding event has occurred, and that a maintenance, verification, or repair action of the heating system, such as of the temperature sensor 34, is necessary.

[0043] Referring now to FIG. 2, there is shown an embodiment of the monitoring circuit 42 having the time member 50, which can be implemented as a discharging RC member, as shown in FIG. 3. As shown in FIG. 3, the discharging RC member can comprise a resistor 56 and a capacitor 58. The time member 50 of FIG. 3 is set to a predetermined voltage and when timing is started, the capacitor 58 starts to discharge over the resistor 56. The decreasing voltage is indicative of the time expired since the start of the discharging. The voltage can be measured at the end clamps shown in FIG. 3.

[0044] Referring back to FIG. 2, the monitoring circuit 42 can further comprise a first energy accumulator 52 and a second energy accumulator 54. The first accumulator 52 is coupled to the power supply 22 and to the heating element 32, via line 26 (FIG. 1). The second energy accumulator 54 is coupled to the line 28 between the supply unit 22 and the temperature sensor 43. Each of line 26 and line 28, can be twin wired supply lines, this, it is possible to charge the first and the second energy accumulator 52, 54, respectively, by connection to only one of the two lines.

[0045] While there has been shown and described what is considered to be preferred embodiments, it will, of course, be understood that various modifications and changes in form or detail could readily be made without departing from the spirit of the invention. It is therefore intended that the invention be not limited to the exact forms described and illustrated, but should be constructed to cover all modifications that may fall within the scope of the appended claims.

LIST OF REFERENCE SIGNS

[0046] 10 Endoscope system [0047] 20 Central unit [0048] 22 Supply unit [0049] 24 Coupling interface [0050] 26 Two-core electric conductor [0051] 28 Two-core electric conductor [0052] 30 Endoscope [0053] 32 Heating element [0054] 34 Temperature sensor [0055] 40 Monitoring unit [0056] 42 Monitoring circuit [0057] 44 Monitoring temperature sensor [0058] 50 Time member [0059] 52 First energy accumulator [0060] 54 Second energy accumulator [0061] 56 Resistor [0062] 58 Capacitor