Measuring device for measuring the temperature of a medical electrode
Patent Information
- Application Number
- EP2024704294
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2023-04-03
- Filing Date
- 2024-02-02
- Publication Date
- 2026-01-07
AI Technical Summary
Existing medical electrodes, particularly neutral electrodes used in electrosurgery, face challenges in monitoring temperature without causing skin overheating, as prior solutions are costly, time-consuming, and incompatible with conventional HF generators, and fail to detect temperature changes accurately.
A measuring device with spatially spaced temperature sensors adhesive to the medical electrode allows for accurate and reliable temperature monitoring, enabling the use of conventional electrodes and compatibility with existing HF generators, with an evaluation unit providing early warnings for temperature deviations.
The solution ensures safe temperature monitoring, preventing skin burns by accurately detecting temperature changes and maintaining compatibility with existing medical equipment, reducing production costs and complexity.
Smart Images
Figure AT2024060029_10102024_PF_FP_ABST
Abstract
Description
[0001] Measuring device for measuring a temperature at a medical electrode
[0002] The invention relates to a measuring device for measuring a temperature and / or a temperature change at a medical electrode separate from the measuring device, preferably a neutral electrode, wherein the measuring device comprises a carrier and at least two temperature sensors arranged on the carrier, an arrangement comprising a medical electrode and such a measuring device, a device for monitoring a temperature at a neutral electrode with such a measuring device and the use of such a measuring device for measuring a temperature at a medical electrode separate from the measuring device.
[0003] Electrosurgery is a widespread procedure that is routinely used in many applications. In German-speaking countries, electrosurgery is used in around 80% of all surgical procedures. During electrosurgical treatment, high-frequency electrical currents are used for cutting and coagulation by conducting the currents through human tissue. A neutral electrode is provided to conduct the currents away from the patient's body.
[0004] The return electrode must not heat the patient's skin above 6°C during tissue ablation or electrosurgery per the AAMI HF-18 standard. RF current return is typically concentrated around the edges of the return electrode (edge effect), resulting in excessive heating at higher current densities. Improper use or a dislodged return electrode may result in second- or third-degree burns to a patient. Therefore, monitoring of the return electrode is imperative to prevent patient injury.
[0005] In the current state of the art, so-called split electrodes are often used for this purpose. These electrodes divide a conductive area into at least two sections. If the electrode is not properly applied or becomes detached during surgery, this can be detected via impedance measurements of the electrode, and a corresponding alarm can be triggered. The disadvantage of this is that the temperature itself cannot be determined.
[0006] Solutions to this problem are known from the prior art. For example, US 2013 / 0158543 discloses a counter electrode with temperature monitoring for electrosurgery. Various embodiments for implementing temperature monitoring are mentioned, for example, via a matrix of two different conductors utilizing the Seebeck effect or via a layer of ferromagnetic material. These elements are always integrated into the electrode.
[0007] However, this makes the production of such an electrode time-consuming and costly, with even small differences making a significant difference in the case of mass-produced items such as neutral electrodes.
[0008] Furthermore, such electrodes are not compatible with conventional RF generators used in RF surgery. These would therefore have to be replaced.
[0009] The object of the invention is to at least partially eliminate the disadvantages described above and to provide a measuring device which is improved compared to the prior art, an arrangement comprising a medical electrode and such a measuring device, a device for monitoring a temperature and / or a temperature change at a neutral electrode with such a measuring device and the use of such a measuring device for measuring a temperature and / or a temperature change at a medical electrode which is separate from the measuring device.
[0010] This object is achieved by the features of independent claims 1 and 10 , 14 and 20 .
[0011] According to the invention, it is therefore provided that the at least two temperature sensors are spatially spaced from one another and that an adhesive layer is provided, via which the measuring device can be arranged on a medical electrode, preferably on an upper side of the medical electrode facing away from the skin.
[0012] This allows a measuring device to be glued onto a conventional neutral electrode and the temperature at the neutral electrode to be monitored.
[0013] Surprisingly, it has been shown that the measurement on the base material of the medical electrode (web, tape, foam) is sufficiently accurate and reliably detects temperature changes between human skin and the gel / conductive layer of the neutral electrode. Any correction factors are set by the temperature sensors themselves and / or by an evaluation unit.
[0014] Because the measuring device can be glued to a conventional electrode, inexpensive, conventional neutral electrodes can continue to be used. When needed, a measuring device is simply attached to the medical electrode.
[0015] Conventional RF generators can also continue to be used; a separate evaluation unit can be provided for the measuring device.
[0016] By spatially spacing at least two temperature sensors, the temperature on the medical electrode can be measured at two spatially spaced points, thus achieving greater safety.
[0017] An arrangement according to the invention comprises a medical electrode , preferably a neutral electrode , and a measuring device , wherein the measuring device is arranged on the medical electrode , preferably on an upper side of the medical electrode facing away from the skin .
[0018] A device according to the invention for monitoring a temperature at a neutral electrode comprises a measuring device and an evaluation unit which is or can be connected to the measuring device, preferably via a signal line.
[0019] In addition, the use of a measuring device for measuring a temperature at a medical electrode separate from the measuring device is also provided, wherein the measuring device is arranged on the medical electrode, preferably on an upper side of the medical electrode facing away from the skin.
[0020] Further advantageous embodiments of the invention are defined in the dependent claims.
[0021] It can be provided that the carrier is self-adhesive, and the adhesive layer is formed by the self-adhesive carrier. This can further simplify the manufacture of a measuring device.
[0022] Preferably, the measuring device can have 10 to 20, preferably 12 to 16, temperature sensors. With such a number of sensors, the temperature on a medical electrode can be measured at essentially all relevant points.
[0023] It can be provided that the at least two temperature sensors are designed as resistance thermosensors, bimetallic sensors, or thermocouples. However, in principle, any suitable type of temperature sensor is conceivable. This also includes conventional temperature sensors or chips.
[0024] Advantageously, the at least two temperature sensors can be printed onto the carrier. This reduces the space required and the manufacturing effort for a measuring device.
[0025] It can also be provided that the measuring device has at least one conductor for contacting the at least two temperature sensors. Signals from the temperature sensors and / or energy for the temperature sensors can be transported via the at least one conductor.
[0026] Advantageously, at least one conductor can also be printed on the carrier.
[0027] Preferably, it can be provided that the at least two temperature sensors have an accuracy of less than or equal to 0.5° Celsius, preferably less than or equal to 0.1° Celsius. Particularly in the range from 30 to 45° Celsius, it is advantageous if an accuracy of less than or equal to 0.1° Celsius is achieved. This can ensure, among other things, that a sufficiently accurate temperature measurement can be carried out.
[0028] It can also be provided that the measuring device has at least one connection point for connecting a signal line. Signals can be transported from the measuring device to an evaluation unit and vice versa via a signal line.
[0029] With regard to an arrangement according to the invention, it can be provided that the measuring device is designed separately from the medical electrode.
[0030] Advantageously, the measuring device can also be designed to be substantially congruent with the medical electrode. This facilitates the application of a measuring device to a medical electrode. In particular, the correct alignment and arrangement of the measuring device, and thus of the temperature sensors, on the medical electrode can be ensured.
[0031] Particularly preferably, the medical electrode can have at least one contact surface for contacting a patient's skin, wherein the at least two temperature sensors are arranged in an edge region of the at least one contact surface. Since the RF current return is normally concentrated around the edges (the edge region of the contact surfaces) of the neutral electrode, it is advantageous if the temperature is measured at these locations.
[0032] With regard to a device, it can be provided that the evaluation unit is designed to evaluate signals from the measuring device. In the context of the present application, this is to be interpreted such that signals coming from the measuring device (in the case of active temperature sensors) and / or changes occurring due to temperature changes (in the case of passive sensors) are evaluated by the measuring device.
[0033] According to one embodiment, the measuring device can be supplied with energy via the evaluation unit. This makes it easy to ensure the energy supply to the measuring device.
[0034] Preferably, the evaluation unit may be provided with a signaling device, preferably acoustic and / or optical. Such a signaling device can alert a user of the evaluation unit, for example, a surgeon, to an inadmissible temperature drop or increase.
[0035] For this purpose, it can advantageously be provided that the evaluation unit is designed to output a signal via the signaling device upon detection of a predetermined temperature change, preferably a temperature change of + / - 4 ° Celsius. This enables early reaction by the surgical or medical personnel. If a corresponding connection to an HF generator is provided, it would also be possible to actively
[0036] Current flow can be intervened. Furthermore, not only the temperature increase required by the standard (maximum +6° Kelvin) can be measured, but also a temperature drop. A temperature drop can be an indication of an electrode that has become detached from the human skin, since the ambient temperature in an average operating room (~20 degrees Celsius) is significantly lower than the normal skin surface temperature (~33 degrees Celsius). Thus, a temperature drop can also serve as an indicator of an improperly applied electrode.
[0037] Preferably, a relative temperature change is measured, and an inadmissible temperature increase or decrease is detected. However, it would also be possible, in principle, to determine absolute temperatures.
[0038] The device may also be provided with a measurement cycle of less than or equal to 30 seconds. This ensures that an early warning signal can be given in the event of a temperature increase or decrease.
[0039] Further details and advantages of the invention are explained in more detail below with reference to the figures and the drawings.
[0040] Fig. 1a is a schematic plan view of a measuring device,
[0041] Fig. 1b is a schematic bottom view of a measuring device,
[0042] Fig. 2 is a schematic exploded view of a
[0043] measuring device,
[0044] Fig. 3a is a schematic bottom view of an embodiment of a measuring device,
[0045] Fig. 3b is a schematic bottom view of another embodiment of a measuring device,
[0046] Fig. 4a is a schematic perspective view of an arrangement from above, Fig. 4b is a schematic perspective view of an arrangement from below, and
[0047] Fig . 5 is a schematic view of a device .
[0048] Figure 1a shows a schematic top view of a measuring device 1, and Figure 1b shows the corresponding bottom view. In the present embodiment, this concerns the application in conjunction with a neutral electrode for HF surgery.
[0049] The measuring device 1 comprises a carrier 3, onto which, in the present embodiment, conductors 6 and temperature sensors 4 are printed. The conductors 6 can be made of silver, for example, and the temperature sensors 4 of carbon. However, other material variants are also conceivable.
[0050] The temperature sensors 4 are designed as resistance temperature sensors, i.e., they change their electrical resistance depending on the temperature. In principle, a variety of different sensors can be used in a measuring device 1, for example, thermocouples or bimetallic sensors. Furthermore, the temperature sensors 4 and the conductors 6 do not necessarily have to be printed onto the carrier 3. Conventionally designed conductors 6 and temperature sensors 4 can also be used.
[0051] Before and after each temperature sensor 4, the temperature sensors 4 are contacted by a conductor 6, with the conductors 6 being led to a connection point 1a. This allows a voltage drop across the temperature sensors 4 to be measured. This can then be used to determine an increase or decrease in temperature. This is preferably done by measuring the relative temperature change. However, it would also be possible to determine absolute temperature values.
[0052] An adhesive layer 5 is also arranged on the carrier 3.
[0053] The measuring device 1 can be arranged on a medical electrode 2 using an adhesive layer 5. However, the carrier 3 can also be self-adhesive. In this case, the adhesive layer 5 is formed by the self-adhesive carrier 3.
[0054] Finally, a protective film 7 is arranged on the adhesive layer 5 to protect the adhesive layer 5 until the measuring device 1 is applied to a medical electrode 2.
[0055] Figure 2 shows a schematic exploded view of a measuring device 1. The various layers of the measuring device 1 are again visible.
[0056] Figure 3a shows a schematic bottom view of an embodiment of a measuring device 1, and Figure 3b shows a schematic bottom view of another embodiment of a measuring device 1. The protective film 7 and the adhesive layer 5 are not shown in these figures.
[0057] The embodiments according to Figures 3a and 3b differ in the number of temperature sensors 4; in Figure 3b, two additional temperature sensors 4 are provided.
[0058] In addition, it is indicated where contact surfaces 2c of a medical electrode 2 would be located if the measuring device 1 were arranged on a medical electrode 2. It can be seen that the temperature sensors 4 are arranged in an edge region of the contact surfaces 2c. This is because the currents returned via the medical electrode 2 are concentrated in the edge region, which is why the greatest temperature increase can be expected in this region.
[0059] Figure 4b shows a schematic, perspective view of an arrangement 8 comprising a medical electrode 2 and a measuring device 1 from above, and Figure 4b shows the same from below. The measuring device 1 is arranged on an upper side 2a facing away from the skin. The contact surfaces 2c of the medical electrode 2 are arranged on the underside 2b of the electrode on a carrier 2d.
[0060] It can be seen that the measuring device 1 is designed essentially congruently with the medical electrode 2. This ensures that the measuring device 1 is correctly positioned on a medical electrode 2 and that the temperature sensors 4 are also positioned correctly on the medical electrode 2.
[0061] The medical electrode 2 also has a connection point 2e for connecting a signal conductor for the medical electrode 2. The medical electrode 2 further comprises an adhesive with which the medical electrode 2 can be arranged on the skin of a patient. The adhesive can be electrically conductive in order to establish a conductive connection between the skin of a patient and the contact surfaces 2c of the medical electrode 2. The adhesive is not shown in the present figures. A protective film 7, which can be arranged on the adhesive, is also not shown.
[0062] Figure 5 shows a schematic view of a device 100. An evaluation unit 101 is provided, which can evaluate signals 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 arranged on a medical electrode 2, forming an arrangement 8.
[0063] If the measuring device 1 is designed as shown in Figures 1 to 4, the evaluation unit 101 can measure the voltage drop across the individual temperature sensors 4. From this, a relative temperature change and, subsequently, a temperature increase or decrease can be detected. However, it is also conceivable that absolute temperatures are measured, and a temperature increase or decrease can be detected from this.
[0064] If the temperature rises or falls by more than a predetermined limit, a warning signal can be emitted via a signaling device 103. This can be optical and / or acoustic, for example. The limit can be set at + / - 4° Celsius, for example. This allows early intervention and possible injury to a patient to be prevented.
[0065] With a corresponding connection to an RF generator 104, it is also conceivable that, if the limit value is exceeded, the power supply is actively intervened in and, for example, the current flow is reduced.
[0066] Figure 5 shows such an RF generator 104. The RF generator 104 is connected via a cable 104a to a medical electrode 2, via which current can be fed back from a patient to the RF generator 104.
[0067] Also shown is an active electrode 104b, which is supplied with power by the RF generator 104. Cutting and / or coagulation can be performed via the active electrode 104b using electrical current.
[0068] Reference character list:
[0069] 1 measuring device la connection point
[0070] 2 Medical Electrode
[0071] 2a top
[0072] 2b bottom
[0073] 2 c contact surface
[0074] 2d beam
[0075] 2nd junction
[0076] 3 carriers
[0077] 4 Temperature sensor
[0078] 5 adhesive layer
[0079] 6 ladders
[0080] 7 Protective film
[0081] 8 Arrangement
[0082] 100 device
[0083] 101 Evaluation unit
[0084] 102 Signal line
[0085] 103 Signaling device
[0086] 104 HF Generator
[0087] 104a Cable
[0088] 104b Active electrode
Claims
Patent claims 1. Measuring device (1) for measuring a temperature and / or a temperature change at a medical electrode (2) separate from the measuring device, preferably a neutral electrode, wherein the measuring device (1) comprises a carrier (3) and at least two temperature sensors (4) arranged on the carrier (3), characterized in that the at least two temperature sensors (4) are spatially spaced from one another and that an adhesive layer (5) is provided, via which the measuring device (1) can be arranged on a medical electrode (2), preferably on an upper side (2a) of the medical electrode (2) facing away from the skin.
2. Measuring device according to claim 1, wherein the carrier (3) is self-adhesive and the adhesive layer (5) is formed by the self-adhesive carrier (3).
3. Measuring device according to one of claims 1 or 2, wherein the Measuring device (1) 10 to 20, preferably 12 to 16, temperature sensors (4).
4. Measuring device according to one of claims 1 to 3, wherein the at least two temperature sensors (4) are designed as resistance thermosensors, bimetal sensors and / or thermocouples.
5. Measuring device according to one of claims 1 to 4, wherein the at least two temperature sensors (4) are printed on the carrier (3).
6. Measuring device according to one of claims 1 to 5, wherein the measuring device (1) has at least one conductor (6) for contacting the at least two temperature sensors (4).
7. Measuring device according to claim 6, wherein the at least one conductor (6) is printed on the carrier (3).
8. Measuring device according to one of claims 1 to 7, wherein the at least two temperature sensors (4) have an accuracy of less than or equal to 0.5° Celsius, preferably less than or equal to 0.1° Celsius.
9. Measuring device according to one of claims 1 to 8, wherein the measuring device (1) has at least one connection point (1a) for Connection of a signal line (102).
10. Arrangement (8) comprising a medical electrode (2), preferably a neutral electrode, and a measuring device (1) according to one of claims 1 to 9, wherein the measuring device (1) is arranged on the medical electrode (2), preferably on an upper side of the medical electrode (2) facing away from the skin.
11. Arrangement according to claim 10, wherein the measuring device (1) is formed separately from the medical electrode (2).
12. Arrangement according to one of claims 10 or 11, wherein the measuring device (1) is designed substantially congruent to the medical electrode (2).
13. Arrangement according to one of claims 10 to 12, wherein the medical electrode (2) has at least one contact surface (2c) for contacting a skin of a patient, wherein the at least two temperature sensors (4) are arranged in an edge region of the at least one contact surface (2c).
14. Device (100) for monitoring a temperature and / or a temperature change at a medical electrode (2), preferably a neutral electrode, comprising a measuring device (1) according to one of claims 1 to 9 and an evaluation unit (101) which is or can be connected to the measuring device (1), preferably via a signal line (102).
15. Device according to claim 14, wherein the evaluation unit (101) is designed to evaluate signals of the measuring device (1).
16. Device according to one of claims 14 or 15, wherein the measuring device (1) can be supplied with energy via the evaluation unit (101).
17. Device according to one of claims 14 to 16, wherein the evaluation unit (101) has a preferably acoustic and / or optical signaling device (103).
18. Device according to claim 14 to 17, wherein the evaluation unit (101) is designed to output a signal via the signaling device (103) upon detection of a predetermined temperature change, preferably a temperature change of + / - 4° Celsius.
19. Device according to one of claims 14 to 18, wherein the device (100) has a measuring cycle of less than or equal to 30 seconds.
20. Use of a measuring device (1) according to one of claims 1 to 9 for measuring a temperature and / or a temperature change on a medical electrode (2) separate from the measuring device (1), wherein the measuring device (1) is arranged on the medical electrode (2), preferably on an upper side (2a) of the medical electrode (2) facing away from the skin.