A measuring device for measuring temperature at medical electrodes.

Abstract

A measuring device (1) for measuring the temperature and / or temperature change of a separate medical electrode (2), preferably a neutral electrode, wherein the measuring device (1) has a support (3) and at least two temperature sensors (4) disposed on the support (3), the at least two temperature sensors (4) being spatially separated from each other, and is provided with an adhesive layer (5) that allows the measuring device (1) to be placed on the medical electrode (2), preferably on the upper surface (2a) of the medical electrode (2) opposite to the skin.

Description

Technical Field

[0001] The present invention relates to a measuring device for measuring temperature and / or temperature change at a separate medical electrode, preferably a neutral electrode, the measuring device comprising a support and at least two temperature sensors arranged on the support, a device comprising the medical electrode and the above-mentioned measuring device, a device for monitoring the temperature at the neutral electrode provided with the above-mentioned measuring device, and the use of a measuring device for measuring the temperature at a separate medical electrode.

[0002] Electrosurgery is a widely used method that is routinely used in many applications. In the German-speaking region, electrosurgery is used in approximately 80% of surgical procedures. In electrosurgical treatment, high-frequency currents for excision and coagulation are used by passing an electric current through human tissue. In this case, a neutral electrode is provided for redrawing the current from the patient's body.

[0003] During ablation of tissue or during electrosurgery according to the AAMI HF18 standard, the neutral electrode must not heat the patient's skin to a temperature exceeding 6°C. HF current feedback usually concentrates around the edge of the neutral electrode (edge effect), so excessive heating occurs when the current density is high. If used inappropriately or if the neutral electrode peels off, there is a risk of second- or third-degree burns in the patient. Therefore, mandatory monitoring of the neutral electrode is essential to prevent patient injury.

[0004] For this purpose, so-called split electrodes are often used in the prior art. In this electrode, the conductive region is divided into at least two sections. If the electrode is not properly attached or comes off during the operation process, this can be determined through impedance measurement of the electrode and a corresponding alarm can be triggered. The drawback in this case is that the temperature itself cannot be calculated.

[0005] Solutions to these problems are known from the prior art. For example, U.S. Patent Application Publication No. 2013 / 0158543 discloses a counter electrode with temperature monitoring for electrosurgical procedures. Various embodiments for temperature monitoring are described, for example, one using a matrix of two different conductors utilizing the Seebeck effect, or one using a layer of ferromagnetic material. These elements are incorporated into the electrode in this example.

[0006] However, this means that manufacturing such electrodes is time-consuming and expensive, and for solid items like neutral electrodes, even small differences can lead to a significant increase in weight.

[0007] Furthermore, these electrodes are not compatible with conventional HF generators used in HF surgery. Therefore, in such cases, they must be replaced.

[0008] The object of the present invention is to at least partially overcome the aforementioned drawbacks and to provide an improved measuring device compared to the prior art, a medical electrode, and an apparatus comprising the measuring device, an apparatus for monitoring the temperature and / or temperature change at a neutral electrode using the measuring device, and the use of a measuring device for measuring the temperature and / or temperature change at a medical electrode separate from the measuring device.

[0009] The above problems are solved by the features of independent claims 1 and 10, 14 and 20.

[0010] Therefore, according to the present invention, at least two temperature sensors are spatially separated from each other, and an adhesive layer is provided that allows the measuring device to be placed on a medical electrode, preferably on the upper surface of the medical electrode opposite to the skin.

[0011] This allows the measuring device to be attached to a conventional neutral electrode, enabling monitoring of the temperature at the neutral electrode.

[0012] Remarkably, measurements on the substrates of medical electrodes (web, tape, foam) were sufficiently accurate, and temperature changes between human skin and the gel / conductor layer of the neutral electrode were reliably detected. Any correction factors that may arise are set by the temperature sensor itself and / or the evaluation unit.

[0013] Furthermore, because the measuring device can be bonded to conventional electrodes, low-cost conventional neutral electrodes can continue to be used. The measuring device can also be easily attached to medical electrodes when necessary.

[0014] Conventional HF generators can still be used, and a separate evaluation unit can be provided for the measuring device.

[0015] By spatially separating at least two temperature sensors, the temperature at the medical electrode can be measured at two spatially separated points, thereby achieving an even higher level of safety.

[0016] The apparatus according to the present invention includes a medical electrode, preferably a neutral electrode, and a measuring device positioned on the medical electrode, preferably on the upper surface of the medical electrode opposite to the skin.

[0017] The apparatus for monitoring the temperature at a neutral electrode according to the present invention includes a measuring device and an evaluation unit which is preferably connected to or connectable to the measuring device via a signal line.

[0018] Furthermore, the use of a measuring device for measuring temperature on a medical electrode separate from the measuring device is also configured, wherein the measuring device is positioned on the medical electrode, preferably on the upper surface of the medical electrode opposite to the skin.

[0019] Other advantageous embodiments of the present invention are provided in each dependent claim.

[0020] The support can be formed to be self-adhesive, and the adhesive layer can be further formed from the self-adhesive support. This further simplifies the manufacturing of the measuring device.

[0021] Preferably, the measuring device can have 10 to 20, and more preferably 12 to 16, temperature sensors. Using this number of sensors, the temperature at the medical electrode can be measured at virtually all points of interest.

[0022] At least two temperature sensors can be configured as resistance temperature sensors, bimetallic sensors, or thermocouples. However, basically, any temperature sensor of the appropriate type is acceptable. Therefore, temperature sensors include conventional temperature sensors or chips.

[0023] Advantageously, at least two temperature sensors can be configured to be printed on the support. This reduces both the space required for the measuring device and the manufacturing effort.

[0024] The measuring device may also be configured to have at least one conductor for contacting at least two temperature sensors. Temperature sensor signals and / or energy can be transmitted to the temperature sensors through at least one conductor.

[0025] Advantageously, at least one conductor can be printed on the support.

[0026] Preferably, at least two temperature sensors can be configured to have an accuracy of 0.5°C or less, preferably 0.1°C or less. In particular, achieving an accuracy of 0.1°C or less is advantageous in the 30°C to 45°C range. This ensures that sufficiently accurate temperature measurements can be performed.

[0027] Furthermore, the measuring device can be configured to have at least one connection position for connecting the signal line. Signals can be transported from the measuring device to the evaluation unit via the signal line and vice versa from the evaluation unit to the measuring device.

[0028] Regarding the device according to the present invention, the measuring device can be configured to be separate from the medical electrode.

[0029] Advantageously, the measuring device can be configured to be substantially congruent with the medical electrode. This facilitates the attachment of the measuring device to the medical electrode. In particular, it is possible to ensure proper orientation and placement of the measuring device and thus the temperature sensor on the medical electrode.

[0030] Particularly preferably, the medical electrode can have at least one contact surface for contact connection to the patient's skin, where at least two temperature sensors are arranged in the edge region of the at least one contact surface. Since the HF current feedback usually concentrates around the edge (edge region of the contact surface) of the neutral electrode, it is advantageous to measure the temperature at such locations.

[0031] Regarding the device, the evaluation unit can be configured to evaluate the signals of the measuring device. In the context of this application, this means that it is designed such that the changes generated by the signals arriving from the measuring device (in the case of an active temperature sensor) and / or by the temperature change (in the case of a passive sensor) are evaluated by the measuring device.

[0032] According to one embodiment, energy can be supplied to the measuring device via the evaluation unit. Thereby, the energy supply of the measuring device can be easily ensured.

[0033] Preferably, the evaluation unit can preferably have an acoustic signal device and / or an optical signal device. Through such a signal device, the user of the evaluation unit, for example, the surgeon, can be alerted to unacceptable temperature drops or temperature increases.

[0034] To this end, the evaluation unit can be configured to output a signal via a signaling device when a predetermined temperature change is detected, preferably when a temperature change of ±4°C occurs. This allows for an early response by surgical or medical staff. If appropriate coupling to an HF generator is possible, it is also possible to actively intervene in the current flow.

[0035] Furthermore, in addition to being able to measure the upward temperature increase (up to +6°K) required by the standard, it is also possible to measure the temperature decrease. The temperature decrease can be an indicator that the electrode has detached from human skin, because the average ambient temperature in an operating room (approximately 20°C) is clearly below the normal skin surface temperature (approximately 33°C). Therefore, the temperature decrease can also be used as an indicator that the electrode is not properly attached.

[0036] In this case, the relative temperature change is preferably measured, and any unacceptable temperature rise or fall is detected from it. It is also possible to calculate the absolute temperature.

[0037] The device can also be configured to have a measurement cycle of 30 seconds or less. This ensures that an early warning signal can be issued during heating or temperature drops.

[0038] Further details and advantages of the present invention will be described in detail below with reference to the drawings. [Brief explanation of the drawing]

[0039] [Figure 1a] This is a schematic top view showing the measuring device. [Figure 1b] This is a schematic bottom view showing the measuring device. [Figure 2] This is a schematic exploded view showing the measuring device. [Figure 3a] This is a schematic bottom view showing one embodiment of the measuring device. [Figure 3b] This is a schematic bottom view showing another embodiment of the measuring device. [Figure 4a] This is a schematic perspective view showing the device from above. [Figure 4b] This is a schematic perspective view showing the device from below. [Figure 5] This is a schematic diagram showing the device.

[0040] Figure 1a shows a schematic top view of the measuring device 1, and Figure 1b shows a corresponding bottom view. In this embodiment, this relates to an application for a neutral electrode used in HF surgery.

[0041] The measuring device 1 has a support 3, on which, in this embodiment, a conductor 6 and a temperature sensor 4 are printed. In this case, the conductor 6 can be manufactured from, for example, silver, and the temperature sensor 4 can be manufactured from carbon. Variations using other materials are also possible.

[0042] Here, the temperature sensor 4 is configured as a resistance temperature sensor, that is, a sensor that changes its electrical resistance depending on the temperature. Basically, various sensors, such as thermocouples or bimetallic sensors, can be used in the measuring device 1. Furthermore, there is absolutely no need to print the temperature sensor 4 and conductor 6 onto the support 3. Conventional conductors 6 and temperature sensor 4 can also be used.

[0043] A conductor 6 is in contact with each temperature sensor 4 both in front of and behind it, with the conductor 6 extended to the connection position 1a. This allows for the measurement of the voltage drop across the temperature sensor 4. From this, a temperature rise or fall can be calculated. This is preferably done by measuring the relative temperature change. It is also possible to calculate the absolute temperature value.

[0044] An adhesive layer 5 is also placed on the support 3. The measuring device 1 can be placed on the medical electrode 2 via the adhesive layer 5. However, the support 3 may be formed to be self-adhesive. In this case, the adhesive layer 5 is formed from the self-adhesive support 3.

[0045] Finally, a protective film 7 is placed on the adhesive layer 5 to protect it until the measuring device 1 is attached to the medical electrode 2.

[0046] Figure 2 shows a schematic exploded view of the measuring device 1. Here, too, the various layers of the measuring device 1 can be seen.

[0047] Figure 3a shows a schematic bottom view of one embodiment of the measuring device 1, and Figure 3b shows a schematic bottom view of another embodiment of the measuring device 1. The protective film 7 and adhesive layer 5 are not shown in these figures.

[0048] The number of temperature sensors 4 differs between the embodiment shown in Figure 3a and the embodiment shown in Figure 3b, with Figure 3b having two additional temperature sensors 4.

[0049] Furthermore, the location of the contact surface 2c of the medical electrode 2 when the measuring device 1 is placed on the medical electrode 2 is shown. It can be seen that the temperature sensor 4 is positioned in the edge region of the contact surface 2c. In other words, since the concentration of the current fed back through the medical electrode 2 occurs in the edge region, the maximum temperature rise can be predicted in that region.

[0050] Figure 4a shows a schematic perspective view of the apparatus 8, which consists of a medical electrode 2 and a measuring device 1, as seen from above, and Figure 4b shows a schematic perspective view of the same apparatus 8 as seen from below.

[0051] At this time, the measuring device 1 is positioned on the upper surface 2a opposite to the skin. The contact surface 2c of the medical electrode 2 is positioned on the lower surface 2b of the electrode on the support 2d.

[0052] It can be seen that the measuring device 1 is formed substantially jointly with the medical electrode 2. This ensures that the measuring device 1 is correctly positioned on the medical electrode 2, and consequently, that the temperature sensor 4 is also installed in the correct position on the medical electrode 2.

[0053] The medical electrode 2 also has a connection position 2e for connecting a signal conductor to the medical electrode 2. The medical electrode 2 further includes an adhesive that can be placed on the patient's skin. In this case, the adhesive can be configured to be conductive in order to form a conductive connection between the patient's skin and the contact surface 2c of the medical electrode 2. The adhesive is not shown in this figure. Nor is the protective film 7 that can be placed on the adhesive shown.

[0054] Figure 5 shows a schematic diagram of the apparatus 100. An evaluation unit 101 is provided, which can evaluate the signal from the measuring device 1. The measuring device 1 is connected to the evaluation unit 101 via a signal line 102. The measuring device 1 is further placed on a medical electrode 2, thereby forming the apparatus 8.

[0055] If the measuring device 1 is configured as shown in Figures 1 to 4, the evaluation unit 101 can measure the voltage drop via the individual temperature sensors 4. In this case, relative temperature changes and the resulting temperature rise or fall can be detected based on the voltage drop.

[0056] Furthermore, it is also possible to measure the absolute temperature and detect a temperature increase or decrease from that value.

[0057] If the temperature rises or falls beyond a set limit, a warning signal can be output via the signaling device 103. The warning signal may be, for example, optical and / or acoustic. The limit can be set to, for example, ±4°C. This allows for early intervention and can prevent potential patient injury.

[0058] If the HF generator 104 is properly coupled, if the limit value is exceeded, active intervention will be performed on the current supply unit, making it possible to reduce the current flow, for example.

[0059] Figure 5 shows the HF generator 104 in this configuration. The HF generator 104 is connected to the medical electrode 2 via cable 104a, and the current from the patient can be fed back to the HF generator 104 via the medical electrode 2.

[0060] An active electrode 104b is also shown here, and current is supplied to this active electrode 104b from the HF generator 104. Excision and / or coagulation using current can be performed via the active electrode 104b. [Explanation of Symbols]

[0061] 1. Measuring device 1a Connection location 2 Medical electrodes 2a Top side 2b Bottom side 2c contact surface 2d support 2e Connection location 3 Support 4. Temperature Sensor 5 Adhesive layer 6 Conductors 7. Protective film 8 equipment 100 devices 101 evaluation units 102 Signal Line 103 Signaling device 104 HF Generator 104a cable 104b active electrode

Claims

1. A measuring device (1) for measuring the temperature and / or temperature change at a separate medical electrode (2), preferably a neutral electrode, The measuring device (1) includes a support (3) and at least two temperature sensors (4) disposed on the support (3), In measuring device (1), The at least two temperature sensors (4) are spatially separated from each other. An adhesive layer (5) is provided that allows the measuring device (1) to be placed on the medical electrode (2), preferably on the upper surface (2a) of the medical electrode (2) opposite to the skin. A measuring device (1) characterized by the following.

2. The measuring device according to claim 1, wherein the support (3) is formed to be self-adhesive, and the adhesive layer (5) is formed by the self-adhesive support (3).

3. The measuring device (1) has 10 to 20, preferably 12 to 16, temperature sensors (4), according to claim 1 or 2.

4. The measuring device according to any one of claims 1 to 3, wherein the at least two temperature sensors (4) are formed as resistance temperature sensors, bimetallic sensors and / or thermocouples.

5. The measuring device according to any one of claims 1 to 4, wherein at least two temperature sensors (4) are printed on the support (3).

6. The measuring device (1) has at least one conductor (6) for contact connection with the at least two temperature sensors (4), according to any one of claims 1 to 5.

7. The measuring device according to claim 6, wherein the at least one conductor (6) is printed on the support (3).

8. The measuring device according to any one of claims 1 to 7, wherein the at least two temperature sensors (4) have an accuracy of 0.5°C or less, preferably 0.1°C or less.

9. The measuring device (1) has at least one connection position (1a) for connection to a signal line (102), according to any one of claims 1 to 8.

10. A device (8) comprising a medical electrode (2), preferably a neutral electrode, and a measuring device (1) according to any one of claims 1 to 9, The measuring device (1) is positioned on the medical electrode (2), preferably on the upper surface of the medical electrode (2) opposite to the skin. Device (8).

11. The apparatus according to claim 10, wherein the measuring device (1) is formed separately from the medical electrode (2).

12. The apparatus according to claim 10 or 11, wherein the measuring device (1) is formed substantially jointly with the medical electrode (2).

13. The apparatus according to any one of claims 10 to 12, wherein the medical electrode (2) has at least one contact surface (2c) that is in contact with the patient's skin, and the at least two temperature sensors (4) are arranged in the edge region of the at least one contact surface (2c).

14. A medical electrode (2), preferably a device (100) for monitoring the temperature and / or temperature change at a neutral electrode, A measuring device (1) according to any one of claims 1 to 9, and an evaluation unit (101) preferably connected to or connectable to the measuring device (1) via a signal line (102), Apparatus (100).

15. The apparatus according to claim 14, wherein the evaluation unit (101) is configured to evaluate the signal of the measuring device (1).

16. The apparatus according to claim 14 or 15, wherein energy can be supplied to the measuring device (1) via the evaluation unit (101).

17. The apparatus according to any one of claims 14 to 16, wherein the evaluation unit (101) preferably includes an acoustic signaling device and / or an optical signaling device (103).

18. The apparatus according to any one of claims 14 to 17, wherein the evaluation unit (101) is configured to output a signal via the signaling device (103) when a predetermined temperature change is detected, preferably when a temperature change of ±4°C occurs.

19. The apparatus (100) has a measurement cycle of 30 seconds or less, according to any one of claims 14 to 18.

20. A use of the measuring device (1) according to any one of claims 1 to 9 for measuring the temperature and / or temperature change at a separate medical electrode (2), wherein the measuring device (1) is positioned on the medical electrode (2), preferably on the upper surface (2a) of the medical electrode (2) opposite to the skin.

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