Universal cartridge for electrophysiology system adapters

Abstract

The invention is entitled Universal Box for Electrophysiology System Adapter. The device includes a housing having a base and a cover with respective conductive layers. The conductive layers are connected to form a shield that attenuates electromagnetic radiation originating outside the housing in a range of 10 kHz - 100 kHz by at least 20 dB within the housing. An adapter circuit within the housing processes electrophysiology signals to produce output signals. A first connector through the housing connects to a probe to receive electrophysiology signals and to deliver the electrophysiology signals to the adapter circuit. A second connector through the housing receives the output signals from the adapter circuit and delivers the output signals to a console. A control input receives a control signal indicative of a frequency within the range, and a sensing circuit senses a magnetic field within the housing and outputs a warning signal when the magnetic field at the frequency indicated by the control signal exceeds a preset threshold.

Description

Technical Field

[0001] This invention relates generally to electrophysiological systems, and more specifically to adapters that alter the function of such systems. Background Technology

[0002] The manufacture of equipment for medical facilities must comply with multiple standards, such as those defining electromagnetic immunity and resistance to transport vibration. Requirements apply to adapters that add functionality to existing equipment. Such adapters are typically enclosed in dedicated applications. Examples of such applications are shown below.

[0003] U.S. Patent Application 2014 / 0226268, granted to O'Neill et al., describes a claim for protection to enclose and / or protect a mobile electronic device from various hazardous situations, such as impacts, shocks, and / or the entry of potentially harmful substances such as water, other liquids, dust, dirt, sand, and / or other debris.

[0004] U.S. Patent 10,411,749 to Witter et al. describes a protective housing for use with an electronic device. The housing is stated to include a padding layer configured to cover at least a portion of the side surface of the electronic device when it is mounted in the protective housing.

[0005] U.S. Patent Application 2009 / 0034169, granted to Richardson et al., describes a protective casing for an electronic device having a protective casing capable of closing and substantially enclosing the electronic device in a substantially rigid and substantially compression-resistant manner. Summary of the Invention

[0006] Embodiments of the present invention provide an apparatus comprising:

[0007] The outer casing, which consists of the following:

[0008] A base having a base conductive layer; and

[0009] The cover has a cover conductive layer and is configured to engage with a base such that the base conductive layer is connected to the cover conductive layer to form a shield that attenuates electromagnetic radiation originating from outside the housing by at least 20 dB within the housing in the frequency range of 10 kHz–100 kHz.

[0010] An adapter circuit, contained within the housing and configured to process electrophysiological signals and generate an output signal in response to the electrophysiological signals;

[0011] A first connector passes through the outer surface of the housing and has a first outer side configured to connect to a medical probe to receive electrophysiological signals from the medical probe and a first inner side connected to deliver electrophysiological signals to an adapter circuit.

[0012] The second connector passes through the outer surface of the housing and has a second inner side connected to receive an output signal from the adapter circuit and a second outer side configured to connect to the console to deliver the output signal to the console;

[0013] A control input terminal configured to receive a control signal indicating a frequency selection within that range; and

[0014] A sensing circuit is configured to sense the magnetic field within the housing and output a warning signal when the magnetic field of a frequency indicated by a control signal exceeds a preset threshold.

[0015] In the disclosed embodiments, the device includes a plurality of viscoelastic mounts configured to support the adapter circuitry on the base and attenuate mechanical vibrations received by the base at the adapter circuitry.

[0016] In another disclosed embodiment, the cover mates with a first side of the base, and the device further includes a closed heat sink connected to a second side of the base opposite to the first side. The base has a vent configured to transfer hot air through the heat sink from an area near the adapter circuitry in order to cool the hot air and return the cooled air to the area.

[0017] In another disclosed embodiment, the device includes a light-emitting element formed on the cover, the element being configured to be activated in response to the generation of a warning signal.

[0018] In another disclosed embodiment, the sensing circuit includes at least one coil coupled to provide an input signal to the lock-in amplifier. Typically, the medical probe is positioned in a magnetic field alternating at a preset frequency, and a control signal indicating the preset frequency is provided to the lock-in amplifier. The preset frequency may be generated by a control console, and the lock-in amplifier may receive the control signal from the control console via a second connector.

[0019] In an alternative implementation, the preset threshold includes a magnetic field with an amplitude of 1 milligauss.

[0020] According to an embodiment of the present invention, another method is provided, which comprises the following:

[0021] A housing is provided, the housing comprising:

[0022] A base having a base conductive layer, and

[0023] The cover has a cover conductive layer and is configured to engage with a base such that the base conductive layer is connected to the cover conductive layer to form a shield that attenuates electromagnetic radiation originating from outside the housing by at least 20 dB within the housing in the frequency range of 10 kHz–100 kHz.

[0024] The adapter circuit is located within the housing, wherein the adapter circuit is configured to process electrophysiological signals and generate an output signal in response to the electrophysiological signals;

[0025] The first connector passes through the outer surface of the housing, the first connector having a first outer side configured to connect to a medical probe to receive electrophysiological signals from the medical probe and a first inner side connected to deliver the electrophysiological signals to the adapter circuit;

[0026] The second connector passes through the outer surface of the housing, the second connector having a second inner side connected to receive an output signal from the adapter circuit and a second outer side configured to connect to the console to deliver the output signal to the console;

[0027] Configure the control input to receive a control signal indicating the selection of a frequency within that range; and

[0028] Configure a sensing circuit to sense the magnetic field inside the housing and output a warning signal when the magnetic field frequency indicated by the control signal exceeds a preset threshold.

[0029] This disclosure will be more fully understood through the following detailed description of embodiments thereof, taken in conjunction with the accompanying drawings, wherein: Attached Figure Description

[0030] Figure 1 A schematic diagram illustrating an electrophysiological (EP) system for EP surgery according to an embodiment of the present invention;

[0031] Figure 2A and Figure 2B This is a schematic exploded view of the housing and adapter according to an embodiment of the present invention;

[0032] Figure 3A A schematic block diagram illustrating the probe, the adapter and the console in the housing, and their mating connections according to an embodiment of the present invention; and

[0033] Figure 3B A schematic block diagram illustrating a probe, an adapter and a console in a housing, and their mating connections according to an alternative embodiment of the invention. Detailed Implementation

[0034] Overview

[0035] During the lifespan of a system configured for electrophysiological procedures involving the insertion of probes into human subjects, modifications to the system's hardware and software are typically made to enhance its functionality. One method for implementing such modifications is to insert an adapter, comprising software and / or hardware, between the probe and the console to which the probe is typically connected.

[0036] Adapters are typically designed for a specific type of probe; for example, there may be one adapter for probes that include basket catheters, and another adapter for probes that include sling catheters (catheters with flexible distal ends having multiple electrodes).

[0037] Embodiments of the present invention provide a housing configured to accommodate different types of adapters, and the housing allows each accommodated adapter to be connected to its corresponding probe and control console. Furthermore, the housing is configured such that each of its accommodated adapters conforms to three international standards set by the IEC (International Electrotechnical Commission), including one standard for electromagnetic (EM) radiation shielding. Despite conforming to the EM shielding standard, the housing is additionally configured to measure alternating magnetic field radiation that can penetrate the accommodated adapters, and to issue a warning if the level of such radiation exceeds a preset value. Detailed Implementation

[0039] Now for reference Figure 1 This is a schematic illustration of an EP system 20 for electrophysiological (EP) surgery according to an embodiment of the present invention. In the illustrated embodiment, a physician 22 performs a multichannel ablation procedure using system 20 by way of example. The physician 22 is performing the procedure on the heart 52 of the subject 24 using a medical catheter probe 26, the distal end 28 of which includes a plurality of electrodes 30 arranged along the length of the distal end. The electrodes 30 can acquire electrophysiological signals from the heart 52 and / or inject electrical signals into the heart, and are configured to perform ablation. In some embodiments, the electrodes 30 may also be configured for other functions, such as being configured to deliver current to or receive current from an external body patch in order to determine the position of the electrodes in response to the magnitude of the current.

[0040] It should be understood that the signals and currents to electrode 30 mentioned above are transmitted through conductive wiring in probe 26. In some embodiments, signals from other conduits that may not be connected to electrode 30 may also be transmitted through conductive wiring in probe 26 to distal end 28, for example, signals from magnetic field sensor 61 at distal end.

[0041] The EP system 20 includes a processor 32 and multiple modules, as described below, which are accessible to the processor to provide functionality to the probe 26. The processor 32 and modules are typically located within a console 40. The console 40 includes input devices 42 operated by the physician 22, such as a keyboard and mouse. A display screen 44 is positioned close to the console 40. The display screen 44 may optionally include a touchscreen, thus providing another input device.

[0042] Processors 32 typically each include a programmable processor programmed in software and / or firmware to perform the functions described herein. Alternatively or additionally, the processor may include hard-wired and / or programmable hardware logic circuitry that performs at least some of these functions. Although processor 32 and the modules it accesses are shown in the accompanying drawings, for simplicity, they are represented as separate monolithic functional blocks; in reality, some of these functions may be combined in a single processing and control unit. The modules accessed by the processor are described below.

[0043] The processor uses ablation module 34 to provide ablation power to electrode 30. The ablation module includes an IRE (irreversible electroporation) generator 36 and / or an RF (radio frequency) generator 38. Cell death following IRE is due to apoptosis (programmed cell death) rather than necrosis (cell damage, which leads to cell destruction through the action of its own enzymes), as is the case in RF ablation.

[0044] An IRE generator similar to generator 36 is described in U.S. Patent Application 16 / 701,989, which is incorporated herein by reference. IRE generator 36 generates electrical pulse trains that are directed to selected electrodes 30 to perform an IRE procedure. The waveform (timing and amplitude) of the electrical pulse train is controlled by processor 32.

[0045] The RF generator 38 typically produces approximately 100W of sinusoidal power at frequencies in the hundreds of kHz range.

[0046] The tracking module 60 is coupled to the electromagnetic position sensor 61 in its distal end 28, and the module also supplies power to the magnetic field generator 62 at various preset frequencies, typically in the range of approximately 1 kHz to approximately 20 kHz. In the presence of an external alternating magnetic field generated by the generator 62, the electromagnetic position sensor outputs a signal that varies with the sensor's position. Based on these signals, the tracking module 60 can determine the position of the electrode 30 within the heart 52.

[0047] The position tracking method using an external magnetic field was applied to CARTO, manufactured by Biosense Webster Inc. (Irvine, California). TMThe system is implemented and described in detail in U.S. Patents 5,391,199, 6,690,963, 6,484,118, 6,239,724, 6,618,612 and 6,332,089, PCT Patent Publication WO 96 / 05768 and U.S. Patent Application Publications 2002 / 0065455 A1, 2003 / 0120150 A1 and 2004 / 0068178 A1, the disclosures of which are incorporated herein by reference.

[0048] Alternatively or otherwise, module 60 may use a tracking system based on the current transmitted through electrode 30 or the impedance seen by the electrode. In such a system, module 60 estimates the position of a given electrode 30 in response to the current or impedance between a given electrode and a plurality of surface electrodes 63 coupled to the skin of subject 24. The Advanced Current Position (ACL) system manufactured by Biosense-Webster (Irvine, California) and described in U.S. Patent 8,456,182 is such a tracking system, the disclosure of which is incorporated herein by reference.

[0049] The electrocardiogram (ECG) module 46 is used by the processor 32 to acquire, process, and analyze cardiac signals generated at the electrode 30. Analysis typically includes measuring parameters such as the local activation time (LAT) at the electrode location. The values ​​of these parameters can typically be displayed graphically to the operator 22 on the screen 44. The processor can also use module 46 to inject stimulation signals into the selected electrode 30.

[0050] Although probe 26 can be directly connected to interface 64 in console 40 via cable 26C, in embodiments of the invention, adapter circuit 26A, also referred to herein as adapter 26A, housed in housing 100, is connected in series between interface 64 and the cable. To achieve this series connection, cable 26C is connected to connector 152 in housing 100 via cable adapter 26C2, an additional cable 26C3 is connected between connector 156 in housing and interface 64, and adapter 26A is internally coupled to connectors 152 and 156. References below... Figure 2A and Figure 2B Describe the internal connections of adapter 26A within housing 100.

[0051] In the direct connection between probe 26 and cable 26C, processor 32 uses modules 34, 46, and / or 60 to generate the predetermined functions of electrode 30. As described herein, connection adapter 26A adds additional functions to the predetermined functions. Typically, additional functions are introduced into system 20 when the software and hardware versions of the system are updated.

[0052] An example of additional functionality is an update method for calculating LAT values. Additional functionality can be implemented in software within the adapter, but using hardware or a hybrid of hardware and software to add functionality can enhance the flexibility and / or speed of the added features.

[0053] Other examples of additional features include:

[0054] Adding the potential to operate new intracardiac ECG channels for traditional systems;

[0055] Adding real-time display of the catheter tip surface and temperature and microelectrode signals to the traditional system; and

[0056] It provides new signal conditioning features (such as altered amplification and filtering) and a memory for storing calibration parameters of probe 26.

[0057] As described above, the adapter 26A adds additional functionality, and the adapter can be connected between interface 64 and cable 26C without being housed in housing 100. However, housing 100 is configured such that, in addition to enclosing the adapter, it enables the adapter to comply with the following standards of the International Electrotechnical Commission (IEC) of Geneva, Switzerland: IEC 60601-1-2 for electromagnetic shielding; IEC 60529 for solid and liquid ingress; and IEC 60721-4 for vibration reduction. Enclosing the adapter in housing 100 also adds additional protection to system 20, as described below.

[0058] Figure 2A , Figure 2B This is a schematic exploded view of a housing 100 and an adapter 26A according to an embodiment of the invention. The two figures show different sides of the housing. The housing 100 includes a solid rectangular base 104, which is generally formed of an insulating plastic such as polyimide, the upper surface of which is coated with a conductive material, such as copper with a thickness of 1 mm. The conductive coating forms a conductive surface 110. Three substantially similar viscoelastic cylinders 108 are adhered to the base, supporting the adapter 26A adhered to the cylinders in a region 106 above the base. The cylinders 108 are configured to absorb vibrations experienced by the base 104. In one embodiment, the cylinders 108 are configured such that vibrations of 5Hz–2000Hz applied to the base do not affect the operation of the adapter 26A when the adapter is supported by the base.

[0059] The base 104 includes a first vent 112 and a second vent 116, and a closed radiator 120 is attached to the base such that it is located below the base. Typically, a sealing gasket is located between the base 104 and the dissipator 120 to prevent water ingress. The dissipator 120 includes a labyrinthine arrangement 124 of cooling fins 122 on the exterior of the dissipator and metal walls 128 inside the dissipator. The walls are arranged such that, during adapter operation, hot air generated by the adapter 120 near the first vent 112 passes through the vent and enters the arrangement 124. The hot air flows through the arrangement 124 and is cooled by the fins 122 as it passes through, causing the cooled air to re-enter region 106 via the second vent 116.

[0060] A lid 132, typically in the form of an open cuboid or box, is configured to be mounted on and attached to a base 104. The lid 132 is typically formed of an insulating plastic such as polyimide, and its inner surface is coated with a conductive material, such as copper with a thickness of 1 mm, thereby forming an internal conductive surface 136. When the lid 132 is attached to the base 104, the conductive surface 110 of the base contacts the conductive surface 136 of the lid to form a shield 138, such that region 106 is effectively located within a Faraday cage because it is substantially completely surrounded by the conductive material.

[0061] The Faraday cage formed by connecting two conductive surfaces will alternate in the range of 10kHz-100kHz and the magnetic field originating from outside the shell will be attenuated by at least 20dB.

[0062] Within the cover 132, there is a dividing arch 140 that divides region 106 into two sub-regions. The first sub-region 144 is where the hot air described above and generated by adapter 26A is produced. The second sub-region 148 is where cooled air from vent 116 returns.

[0063] The first connector 152 passes through the outer surface 102 and inner surface 114 of the housing 100 by being formed in the first side of the cover 132, and the second connector 156 passes through the inner and outer surfaces of the housing by being formed in the second cover side opposite to the first side. Each connector includes multiple sets of feedthrough pins passing between the inner and outer sides of the connector. Thus, connector 152 has pins passing between the inner side 152I and the outer side 152O of the connector; and connector 156 has pins passing between the inner side 156I and the outer side 156O of the connector. Within region 106, the first port 26AP1 of adapter 26A is coupled to connector 152 via a first connecting cable 26ACP1. Also within region 106, the second port 26AP2 of adapter 26A is coupled to connector 156 via a second connecting cable 26ACP2.

[0064] When cover 132 is attached to base 104, the two conductive surfaces are joined together to form a Faraday cage around adapter 26A, as described above. While the Faraday cage acts as shield 138 to protect adapter 26A from external EM radiation, it should be understood that it is not entirely immune to such radiation. Therefore, leakage EM radiation is typically present within the Faraday cage, which can impair the operation of adapter 26A. Embodiments of the invention address this problem by providing additional elements within housing 100, as described below.

[0065] The inner surface 130 of the cover 132 is part of the inner surface 114 of the housing 100. A magnetic radiation sensing circuit 160, including at least one coil, is mounted on the inner surface 130 of the cover. It is assumed herein that the circuit 160 includes a triaxial sensor (TAS) with three orthogonal coils, and the circuit is also referred to herein as TAS 160. A circuit system 164, including a lock-in amplifier, is also mounted on the inner surface of the cover. The circuit system 164 is coupled to receive a signal generated by the sensing circuit 160. Together with the circuit system 164, the circuit 160 includes a sensing circuit 166, which senses the magnetic field within the housing 100 and outputs the resulting signal in response.

[0066] Circuit system 164 receives power from connector 156 and is also coupled to receive a reference frequency, referred to herein as a control signal. In this document, by way of example, when the connector is coupled to interface 64 of console 40 (… Figure 1 When the control frequency is received from pin 158 of connector 156, pin 158 serves as the control input of sensing circuit 166. However, it should be understood that other forms of control input may exist, such as by separating conductors, such as feedthrough conductors, from connector 156 that penetrates housing 100, or even by mounting a dial that provides the control signal on the housing.

[0067] In a disclosed embodiment of the invention, the reference frequency is one of the frequencies used by the tracking module 60 to power the field generator 62. Typically, the tracking module 60 powers the generator 62 simultaneously at different frequencies. In one embodiment, the circuit system 164 includes a microcontroller that performs a Fast Fourier Transform (FFT) on the input signal to select the reference frequency. Alternatively, the circuit system 164 is multiplexed to operate at all the different frequencies of the tracking module.

[0068] Using a reference frequency, circuit system 164 measures the level of the sensing circuit signal at that reference frequency. If the measured level is greater than a preset value, indicating that the magnetic field passing through sensing circuit 160 is greater than a preset magnetic field threshold, then circuit system 164 is configured to generate a warning signal. In one embodiment, the preset value of the sensing circuit signal is set to 1 μV, and this value is generated when the amplitude of the preset magnetic field threshold is 1 milligauss.

[0069] Warning signals can be used to activate warning light-emitting elements, such as light-emitting diodes (LEDs) 168 mounted on cover 132. Alternatively or otherwise, warning signals can be provided to processor 32 via connector 156, and the processor can use the signals for other actions, such as providing operator 22 with notification on screen 44 that a predefined magnetic field is present at adapter 26A, and / or recording signals acquired by probe 26 when the predefined magnetic field is present.

[0070] Typically, when notified of the presence of a predefined magnetic field at adapter 26A, for example by illumination by LED 168, operator 22 may move housing 100 until the LED stops illuminating, or until notified that the predefined magnetic field is no longer present at the adapter.

[0071] Figure 3A This is a schematic block diagram illustrating the probe 26, the adapter 26A in the housing 100, and the console 40 according to an embodiment of the present invention, and their mating connections. As will be seen from the above description and by inspection... Figure 3A Understood, probe 26 can be directly connected to interface 64 because the connection of cable 26C and interface 64 is matched. Similarly, probe 26 can be directly connected to port 26AP1 of adapter 26A, and port 26AP2 of adapter 26A can be directly connected to interface 64 because the corresponding connections are matched.

[0072] Furthermore, as described herein, in an embodiment of the invention, when adapter 26A is located in housing 100, probe 26 can be connected to port 26AP1 of adapter 26A via connector 152 of housing and associated cable / adapter of connector 152, and port 26AP2 of adapter can be connected to interface 64 via connector 156 and associated cable of connector 156, since all the corresponding connections match.

[0073] It should be understood that any given adapter 26A has a specific function applied to probe 26, and other given adapters typically have different functions added to the probe, such that it is assumed that all such different functions are included within the scope of the present invention.

[0074] Figure 3BA schematic block diagram illustrating a probe 126, an adapter 126A in housing 100, and a console 40, and their mating connections, according to an alternative embodiment of the invention. While for simplicity and clarity the above description has assumed that the probe 26 has a flexible distal end with multiple electrodes and that the associated adapter 26A is housed in housing 100, it should be understood that the scope of the invention includes adapters housed in housing 100 that can be used with other probes.

[0075] The figure illustrates probe 126, which can be any electrophysiological probe known in the art, such as a basket catheter, balloon catheter, or focal catheter. When the adapter is housed in housing 100 and connected to console 40, adapter 126A adds functionality to probe 126, and the connection between probe 126 and console 40 corresponds to the connection between probe 26 and console, respectively, and operates substantially as described above with respect to probe 26.

[0076] Therefore, cable 126C is connected to connector 152 in housing 100 via cable adapter 126C2, and cable 126C3 is connected between connector 156 in housing and interface 64 of console. Within housing 100, the first port 126AP1 of adapter 126A is coupled to connector 152 via first connecting cable 126ACP1. Additionally, the second port 126AP2 of adapter 126A is coupled to connector 156 via second connecting cable 126ACP2.

[0077] It should be understood that the above embodiments are cited by way of example, and the invention is not limited to the specific content shown and described above. Rather, the scope of the invention includes combinations and sub-combinations of the various features described above, as well as variations and modifications thereof, which should be apparent to those skilled in the art upon reading the above description, and which are not disclosed in the prior art.

Claims

1. An apparatus, the apparatus comprising: Housing, the housing comprising: A base, the base including a base conductive layer; and A cover, the cover including a cover conductive layer and configured to engage with the base such that the base conductive layer is connected to the cover conductive layer to form a shield that attenuates electromagnetic radiation originating from outside the housing by at least 20 dB within the housing in a frequency range of 10 kHz to 100 kHz. An adapter circuit, contained within the housing and configured to process electrophysiological signals and generate an output signal in response to the electrophysiological signals; A first connector, which passes through the outer surface of the housing and has a first outer side configured to connect to a medical probe to receive the electrophysiological signal from the medical probe and a first inner side connected to deliver the electrophysiological signal to the adapter circuit; A second connector passes through the outer surface of the housing and has a second inner side connected to receive the output signal from the adapter circuit and a second outer side configured to connect to the console to deliver the output signal to the console; A control input terminal, configured to receive a control signal indicating a frequency selection within the range; and A sensing circuit configured to sense a magnetic field within the housing and output a warning signal when the magnetic field at the frequency indicated by the control signal exceeds a preset threshold.

2. The device of claim 1, further comprising a plurality of viscoelastic mounting members configured to support the adapter circuit on the base and attenuate mechanical vibrations received by the base at the adapter circuit.

3. The apparatus of claim 1, wherein, The cover mates with a first side of the base. The device further includes a closed heat sink connected to a second side of the base opposite to the first side. The base also includes a vent configured to pass hot air through the heat sink from an area near the adapter circuitry to cool the hot air and return the cooled air to the area.

4. The device of claim 1, further comprising a light-emitting element formed on the cover, the element being configured to activate in response to the generation of the warning signal.

5. The apparatus of claim 1, wherein, The sensing circuit includes at least one coil coupled to provide an input signal to the lock-in amplifier.

6. The apparatus of claim 5, wherein, The medical probe is located in a magnetic field that alternates at a preset frequency, and the control signal indicates the preset frequency and is provided to the lock-in amplifier.

7. The apparatus of claim 6, wherein, The preset frequency is generated by the console, and the lock-in amplifier receives the control signal from the console via the second connector.

8. The apparatus of claim 1, wherein, The preset threshold includes a magnetic field with an amplitude of 1 milligauss.

9. A method, the method comprising: A housing is provided, the housing comprising: The base includes a base conductive layer, and A cover, the cover including a cover conductive layer and configured to engage with the base such that the base conductive layer is connected to the cover conductive layer to form a shield that attenuates electromagnetic radiation originating from outside the housing by at least 20 dB within the housing in a frequency range of 10 kHz to 100 kHz. An adapter circuit is positioned within the housing, wherein the adapter circuit is configured to process electrophysiological signals and generate an output signal in response to the electrophysiological signals; The first connector passes through the outer surface of the housing, the first connector having a first outer side configured to connect to a medical probe to receive the electrophysiological signal from the medical probe and a first inner side connected to deliver the electrophysiological signal to the adapter circuit; The second connector passes through the outer surface of the housing, the second connector having a second inner side connected to receive the output signal from the adapter circuit and a second outer side configured to connect to the console to deliver the output signal to the console; Configure the control input to receive a control signal indicating the selection of a frequency within the stated range; and A sensing circuit is configured to sense the magnetic field within the housing and output a warning signal when the magnetic field at the frequency indicated by the control signal exceeds a preset threshold.

10. The method of claim 9, further comprising attaching a plurality of viscoelastic mounting members to the base, the mounting members being configured to support the adapter circuitry on the base and attenuate mechanical vibrations received by the base at the adapter circuitry.

11. The method of claim 9, wherein, The cover mates with a first side of the base, and the method further includes connecting a closed heat sink to a second side of the base opposite to the first side. The base further includes a vent configured to pass hot air through the heat sink from an area close to the adapter circuitry in order to cool the hot air and return the cooled air to the area.

12. The method of claim 9, further comprising forming a light-emitting element on the cover, the element being configured to be activated in response to the generation of the warning signal.

13. The method of claim 9, wherein, The sensing circuit includes at least one coil coupled to provide an input signal to the lock-in amplifier.

14. The method of claim 13, wherein, The medical probe is located in a magnetic field that alternates at a preset frequency, and the control signal therein indicates the preset frequency and is provided to the lock-in amplifier.

15. The method of claim 14, wherein, The preset frequency is generated by the console, and the lock-in amplifier receives the control signal from the console via the second connector.

16. The method of claim 9, wherein, The preset threshold includes a magnetic field with an amplitude of 1 milligauss.

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