(19)
(11)EP 2 456 516 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
05.10.2022 Bulletin 2022/40

(21)Application number: 10802858.0

(22)Date of filing:  21.07.2010
(51)International Patent Classification (IPC): 
A61B 18/12(2006.01)
A61N 1/08(2006.01)
A61N 1/372(2006.01)
A61B 18/14(2006.01)
A61N 1/362(2006.01)
A61N 1/39(2006.01)
(52)Cooperative Patent Classification (CPC):
A61N 1/37223; A61N 1/3629
(86)International application number:
PCT/US2010/042767
(87)International publication number:
WO 2011/011526 (27.01.2011 Gazette  2011/04)

(54)

MAGNETIC SWITCHING DEVICE WITH A SWITCH FORMED BY AN ELECTROCAUTERY PEN

MAGNETISCHE SCHALTVORRICHTUNG MIT EINEM VON EINEM ELEKTROKAUTERSTIFT GEBILDETEN SCHALTER

DISPOSITIF DE COMMUTATION MAGNÉTIQUE AVEC UN COMMUTATEUR FORMÉ PAR UN STYLO ÉLECTROCAUTÈRE


(84)Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO SE SI SK SM TR

(30)Priority: 21.07.2009 US 227351 P

(43)Date of publication of application:
30.05.2012 Bulletin 2012/22

(73)Proprietor: Cardiac Lead Technologies, LLC
Bethesda, Maryland 20817 (US)

(72)Inventors:
  • CHOE, William
    Highlands Ranch Colorado 80129 (US)
  • Yoon, Sang, Won
    Ann Arbor Michigan 48105 (US)

(74)Representative: dompatent von Kreisler Selting Werner - Partnerschaft von Patent- und Rechtsanwälten mbB 
Deichmannhaus am Dom Bahnhofsvorplatz 1
50667 Köln
50667 Köln (DE)


(56)References cited: : 
US-A- 3 311 111
US-A1- 2002 091 413
US-A1- 2005 096 703
US-A1- 2008 027 513
US-B2- 6 771 155
US-A- 4 049 004
US-A1- 2003 050 676
US-A1- 2007 233 200
US-A1- 2009 163 980
  
      
    Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


    Description

    BACKGROUND


    1. Field of Invention



    [0001] This application relates to a magnetic switching device, more particularly to a magnetic switching device for controlling embedded electrical devices.

    2. Discussion of Related Art



    [0002] Currently in the United States, there are thousands of patients implanted with electrical devices, for example, but not limited to, pacemakers and/or implantable cardioverter-defibrillators (ICDs). A pacemaker, also called an artificial pacemaker, is a device which uses electrical impulses, delivered by electrodes contacting the heart muscle, to regulate the beating of the heart. An ICD is a small battery-powered electrical impulse generator which is implanted in patients who are at risk of sudden cardiac death due to ventricular fibrillation and ventricular tachycardia. The ICD is programmed to detect cardiac arrhythmia and correct them by delivering a jolt of electricity.

    [0003] Many patients with such electrical devices will require non-cardiac surgery or procedures at some point during their lifetime which may interfere with their electrical devices. Non-cardiac surgery may include the use of electrocautery during surgery, lithotripsy, for treatment of kidney stones, the use of a transcutaneous electrical nerve stimulation (TENS) device, or radiation therapy in the treatment of cancer. This presents a serious problem, as many electrical devices are sensitive to electromagnetic interference (EMI) from other electrical devices used during surgery. Consequently, many implantable devices are designed with a magnetically operable switch to shut off the device or switch it to a backup mode when a magnetic field is applied. For example, a patient's pacemaker exposed to EMI may malfunction. Similarly, a patient's ICD may mischaracterize EMI as ventricular fibrillation (VF) and may deliver a shock to the patient. VF is a condition in which there is an uncoordinated contraction of the cardiac muscle of the ventricles in the heart, making them quiver rather than contract properly.

    [0004] Several methods have been adopted to avoid the influence of EMI on an embedded electrical device during surgery. However, these methods have some serious limitations. For example, one solution in avoiding EMI is to reprogram the magnetically-switchable device. However, reprogramming generally requires a technically skilled person to be present to reprogram each device, making reprogramming an expensive option.

    [0005] Another known solution is to place a magnet over a magnetically-switchable, electrical device to inactivate or place the device in a backup mode. The type of magnet used is usually a large permanent magnet, such as a donut magnet. Needless to say, it is difficult to position and to ensure that the magnet stay in place during surgery. Shifting of the magnet during an operation could reactivate the magnetically-switchable, electrical device, for example the pacemaker or ICD, and put the patient at risk.

    [0006] The document US 3,311,111 A discloses a magnetic switching device including an external coil coupled to a pushbutton circuit.

    SUMMARY



    [0007] There thus remains a need for a device to facilitate control of embedded electrical devices. The present invention relates to a magnetic switching device as defined in claim 1

    [0008] Disclosed, but not part of the invention is an electrocautery system that includes an electrocautery device; a control circuit electrically connected to the electrocautery device; and an electromagnetic component electrically connected to the control circuit, wherein the electromagnetic component is adapted to be arranged proximate to an exterior surface of an object comprising a magnetically-switchable device therein, and wherein operation of the electrocautery device causes the electromagnetic component to generate a magnetic field of sufficient strength to engage a switch in the magnetically-switchable device.

    [0009] This summary is provided to introduce certain concepts . Further features and advantages of the device, as well as the structure and operation of various devices, are described in detail below with reference to the accompanying drawings.

    BRIEF DESCRIPTION OF THE DRAWINGS



    [0010] 

    Figure 1A is a schematic illustration showing a top view of a magnetic switching device;

    Figure 1B is a side view of the electromagnetic coil of the magnetic switching device of Figure 1A;

    Figure 2A is a schematic diagram of the magnetic switching device during a power off stage;

    Figure 2B is a schematic diagram of the magnetic switching device during a power on stage;

    Figure 3 is a graphical diagram showing simulation results for the strength of the magnetic field delivered at the magnetically-switchable device based on the number of wire turns of the electromagnetic coil;

    Figure 4 is a graphical diagram showing simulation results for the strength of the magnetic field delivered at the magnetically-switchable device based on the skin thickness of the object;

    Figure 5 is a chart comparing various characteristics of the magnetic core of the magnetic switching device.

    Figure 6 is a schematic illustration of a top view of an electrocautery system, not being part of the present invention;

    Figure 7 is a circuit diagram of the electrocautery system, not being part of the present invention;

    Figure 8 is a schematic diagram of the electrocautery system, not being part of the present invention;

    Figure 9 is a schematic diagram of the magnetic switching device having a plurality of coils connected in series to a power sourceand

    Figure 10 is a schematic diagram of the magnetic switching device having a plurality of coils connected in parallel to a plurality of power sources.


    DETAILED DESCRIPTION



    [0011] Figure 1A is schematic illustration of a top view of a magnetic switching device 100. The magnetic switching device 100 includes an electromagnetic component 10 in electrical connection to a control circuit 12. The electromagnetic component 10 may include a patch 14 adapted to be arranged proximate to an exterior surface of an object 20 (see Figure 2A), for example a human medical patient, having an embedded magnetically-switchable device 22 (see Figure 2A), for example a pacemaker or ICD. However, the general concepts of the current invention are not limited to only pacemakers and ICDs implanted in people. Other types of magnetically-switchable devices could be implanted in the patient or even some non-human object. When activated, the control circuit 12 delivers a current I to the electromagnetic component 10 which, in turn, generates a magnetic field B (see Figure 2B) of sufficient strength and orientation to engage a switch (not shown) in the magnetically-switchable device 22 of the object 20. According to one embodiment, the electromagnetic component 10 will generate a magnetic field of approximately 10 to 4500 µT (0.1 to 45 Gauss) when activated.

    [0012] The magnetic field B generated by the electromagnetic component 10 may cause the magnetically-switchable device 22, here a pacemaker, to go VOO, i.e. to revert into back-up mode. According to a further embodiment, the magnetic field B generated by the electromagnetic component 10 may cause the magnetically-switchable device 22, here an ICD, to turn off its sensing function and to go into a backup pacing mode. In either embodiment, deactivation of the electromagnetic component 10, which stops the generation of the magnetic field B, can re-engage the switch of the magnetically-switchable device 22, causing the magnetically-switchable device 22 to revert back to its original settings and to resume normal operation.

    [0013] According to one embodiment, the patch 14 may be an adhesive patch adapted to be affixed to the exterior surface of the object 20. In that case, the adhesive patch may prevent the electromagnetic component 10 from accidentally shifting during surgery potentially moving the electromagnetic component 10 out of the necessary proximity to the magnetically-switchable device 22, thus failing to switch the magnetically-switchable device 22 to a backup mode or some other desired mode of operation during EMI. For these same reasons, the patch width may include additional tolerance to compensate for error during surgery. Alternatively, other fastening devices may be used, such as straps, clips, stickers, suction devices and/or medical tape. The patch 14 may further be reusable or disposable.

    [0014] According to another embodiment, the electromagnetic component 10 further includes a core 16 that is coupled to or positioned on the patch 14. A wire 18, for example an enamel-covered wire, may be wound around the core 16 to produce an electromagnetic coil 11 (see Figure 1B). The wire 18 may provide the electrical connection of the electromagnetic component 10 to the control circuit 12. The wire 18 may be in the range of approximately 0.3 to 1.3 millimeters in diameter, for example. According to another embodiment, the wire thickness may range from approximately 0.25 centimeters to 0.6 centimeters.

    [0015] According to a further embodiment of the current invention, the core 16 may be embodied as a plastic donut, a plastic cylinder, a metal cylinder and/or a metal donut. The embodiment of the metal cylinder core 16, for example a ferromagnetic core, may provide a maximum magnetic field, however weight may become a consideration. For example, it may be advisable to limit the weight of the core 16 to approximately 3.6 kg (eight pounds).

    [0016] According to one embodiment, the electromagnetic component 10 may include a heat absorber and/or heat dissipater (not shown) to absorb/dissipate the heat generated by the coil 11. The heat absorber may be embodied as a single-piece insulating layer, a multi-piece insulating layer, or passive/active heat dissipation system, such as a layer of gel. The heat absorber may be coupled to or positioned on the patch 14.

    [0017] Figure 1B is a side view of the electromagnetic coil 11 of the magnetic switching device 100 of Figure 1A. Generally, an electromagnetic coil 11 may refer to a coil of wire that is formed to produce a magnetic field B when current I flows through the coil. One loop of wire 18 is generally referred to as a "turn," and a coil 11 consists of one or more turns. In other words, the coil 11 may be accomplished with a minimum of one loop or turn. As seen in Figure 1B, the wire 18 is wound around the core 16 eight times to produce eight turns. As such, the control circuit 12 may send a current I through the wire 18 to the coil 11 of the electromagnetic component 10 to generate the magnetic field B over the magnetically-switchable device 22 embedded in the object 20.

    [0018] According to one embodiment, the control circuit 12 may transmit approximately five Amperes of current I to the electromagnetic component 10 via the wire 18. Five Amperes is used only as an example of a current I. The current I could be more than five Amperes or it could be less. A smaller current I may reduce the heat generated by the coil 11. In this embodiment, the five Amperes of current I through a wire 18, where the wire 18 is approximately 0.5 millimeters in diameter, may generate approximately 12 Watts of power. The 12 Watts of power may generate approximately 720 J/minute (172 calories/minute).

    [0019] According to another embodiment, the portion of the patch 14 affixed or positioned in close proximity to the exterior surface of the object 20 may be dimensioned as 15 centimeters by 15 centimeters. The coil 11 may have a radius R of approximately 7 centimeters and a height H of approximately 3 centimeters. The current I transmitted from the control circuit 12 to the electromagnetic component 10 may be approximately five Amperes (A).

    [0020] Figure 2A is a schematic diagram of the magnetic switching device 100 during a power off stage. As shown in Figure 2A, the electromagnetic component 10 has been positioned on the exterior surface of an object 20, for example a medical patient, above the object's magnetically-switchable device 22. Here, the control circuit 12, also called an electrocautery generator may comprise a DC or AC power supply 24 electrically connected to the electromagnetic component 10 via a wire 18 having a switch 26, also called an electrocautery pen. The switch 26 may be an on/off switch, a foot petal and/or any other activation device. In Figure 2A, the switch 26 is open, thus preventing the power supply 24 from supplying a current I to the coil 11 of the electromagnetic component 10. The coil 11 of the electromagnetic component 10, therefore, cannot generate a magnetic field B. This may be referred to as the power off stage.

    [0021] Figure 2B is a schematic diagram of the magnetic switching device 100 during a power on stage. In Figure 2B, the switch 26 is closed, thus transmitting current I from the power supply 24 to the coil 11 of the electromagnetic patch 10 which then generates a magnetic field B of sufficient strength to engage the switch in the embedded magnetically-switchable device 22. This may be referred to as the power on stage.

    [0022] According to one embodiment, approximately 800 µT (eight Gauss) may be required to effectuate a backup mode on the magnetically-switchable device 22. Furthermore, the coil 11 may be adapted to generate a magnetic field B that is perpendicular to the skin surface of the object 20. The coil radius R may be sized to accommodate magnetically-switchable devices 22 of different types, sizes and shapes. The coil radius R may be, for example, but not limited to, between 4.2 and 9.5 centimeters. The coil 11 may be embodied as a dot magnet with a highly concentrated and directed magnetic field B. Alternatively, the coil 11 may be provided with a slightly larger radius R for additional tolerance to compensate for the spacing between the coil 11 and the magnetically-switchable device 22 embedded in the object 20. Additional tolerance may be desirable when the center of the magnetically-switchable device 22 is unknown. Furthermore, additional tolerance may compensate for any shifting of the magnetically-switchable device 22 within object 20 due to body movement during surgery.

    [0023] According to another embodiment, the current I is approximately five Amperes, the skin thickness of the object 20 is approximately 5 centimeters, and the magnetic field B is at least 800 µT (eight Gauss) during operation. The skin thickness of the object 20 may be used to determine the distance of the magnetically-switchable device 22 from the coil 11 of the electromagnetic component 10. This distance may be calculated by adding the skin thickness of the object 20, or medical patient, and the patch 14 thickness, where the patch 14 is directly affixed to the exterior surface, or skin, of the object 20.

    [0024] Figure 3 is a graphical diagram showing simulation results for the strength of the magnetic field B delivered at the magnetically-switchable device 22 based on the number of wire turns of the electromagnetic coil 11. As described above, the wire 18 may be wound around the circumference of the core 16 a pre-determined number of times to produce an electromagnetic coil 11 adapted to generate an appropriate magnetic field B during the power on stage. The pre-determined number of turns, for example, but not limited to, may be between 30 and 50 turns of wire 18. Figure 3 depicts a graph of the simulation results of the magnetic switching device 100 based on varying numbers of turns of the wire 18.

    [0025] Figure 3 assumes that an ideal circular coil 11 is used, including, for example, an air or cylindrical/donut fixture that does not generate any magnetic field other than that which is generated by the coil 11. For example, the coil 11 may include a plastic cylinder, as seen in Figures 1A, 1B, 2A and 2B. Such an ideal circular coil 11 is depicted to the right of the graph in Figure 3. This assumes that the skin thickness of the object 20 is approximately five centimeters. Skin thickness may be used to calculate the depth of the magnetically-switchable device 22 in the object 20, which may in turn be used to calculate the strength of the magnetic field B experienced at the magnetically-switchable device 22. This further assumes that the current through the wire 18 is approximately five Amperes. In this embodiment, the electromagnetic component 10 requires a minimum magnetic field B of 800 µT (eight Gauss) to generate a magnetic field B of sufficient strength to engage the switch (not shown) of the magnetically-switchable device 22. A coil 11 having 40 turns of wire and a coil radius of approximately eight centimeters would produce a magnetic field B of approximately 960 µT (9.6 Gauss), as shown in Example A. Meanwhile, a coil 11 having 50 turns of wire and a coil radius of approximately seven centimeters would produce a magnetic field of B of approximately 1.2 mT (12 Gauss), as shown in Example C. This embodiment shows that the strength of the magnetic field B at the magnetically-switchable device 22 is proportional to the number of wire turns and depends on the coil radius. The coil 11 is not limited to 40 or 50 turns of the wire 18, other embodiments, for example 30 turns of wire, are also possible.

    [0026] Figure 4 is a graphical diagram showing simulation results for the strength of the magnetic field B delivered at the magnetically-switchable device 22 based on the skin thickness of the object 20. As described above, an object's 20 skin thickness may be used to determine the depth of the magnetically-switchable device 22 within the object 20 and, thus, the strength of the magnetic field B at that depth. According to one embodiment, the depth of the magnetically-switchable device 22 will not exceed a depth of 12.7 cm (five inches) from the skin surface.

    [0027] In Example D of Figure 4, an object's 20, or patient's, skin thickness is approximately seven centimeters. Under Example D, an approximately 9.5 centimeter coil radius will generate a magnetic field B of approximately 875 µT (8.75 Gauss). In Example E, an object's 20, or patient's, skin thickness is approximately five centimeters. Under Example E, an approximately seven centimeter coil radius will produce a magnetic field B of approximately 1.2 mT (12 Gauss). Likewise, when an object's 20, or patient's, skin thickness is one centimeter, an approximately 4.2 centimeter coil radius will produce the maximum magnetic field B at the given skin thickness (not shown). Figure 4 demonstrates the need to optimize the radius of the coil 11 depending on depth of the magnetically-switching device 22 within the object.

    [0028] Figure 5 is a chart comparing various characteristics of the core 16 of the magnetic switching device 100. According to one embodiment, the coil 11 may include an insulator or air core 16', as depicted to the top left of the chart. An insulator core refers to an insert that is positioned within the coil 11 and that is constructed from plastic or another insulating material. An air core simply refers to the coil 11 having a non-existent hollow core, i.e. it uses open spaces between the loops of the coil 11 for air. An insulator/air core 16' is light-weight, low-cost, easy to fabricate and produces an acceptable amplitude of the magnetic field B. Any wire 18 may be used with the insulator/air core 16'. However, the insulator/air core 16' does not allow for precise control of the direction of the magnetic field B and produces a smaller amplitude of magnetic field B than would the metal/ferromagnetic core 16" in Figure 5. The example shown in Figure 5 is a cylinder, however other shapes, such as a donut, may be used.

    [0029] According to another embodiment, the coil 11 may include a metal/ferromagnetic core 16", as depicted to the top right of the chart. The metal/ferromagnetic core 16" may be constructed from iron, nickel, or any other ferromagnetic material. The metal/ferromagnetic core 16" has an acceptable amplitude of the magnetic field B and has a better control of the direction of the magnetic field B than the insulator/air core 16' Specifically, the metal/ferromagnetic core 16" is better able to concentrate or focus the magnetic field B towards the magnetically-switchable device 22 embedded in the object 20. However, the metal/ferromagnetic core 16" is heavy, more expensive and harder to fabricate. Further, the metal/ferromagnetic core 16" must be used in conjunction with a wire 18 which is coated with an insulator or, alternatively, the surface of the core 16" itself must be coated with an insulator.

    [0030] Figure 6 is a schematic illustration of a top view of an electrocautery system 600, in accordance with the present disclosure, but not part of the invention. According to the disclosure, a control circuit 12, including a power unit 62 and switch box 64, is in electrical connection with both an electromagnetic component 10 and an electrocautery device 66. The electrocautery device 66 may be any device used for electrocauterization, i.e. the process of destroying tissue using heat conduction from a metal probe heated by an electric current, and may be referred to as an electrocautery pen. According to the disclosure, when in use, the electrocautery device 66 triggers an input into the switch box 64, which switches on the power unit 62 to send an output current I to the electromagnetic component 10. As with the prior embodiments, the electromagnetic component 10 is adapted to be arranged proximate to an exterior surface of an object 20 having an embedded magnetically-switchable device 22 (see Figures 2A and 2B). When current I is transferred from the power unit 62 to the electromagnetic component 10, the electromagnetic component 10 is adapted to generate a magnetic field B of sufficient strength to engage a switch in the magnetically-switchable device 22.

    [0031] This embodiment prevents EMI from interfering with the object's 20 magnetically-switchable device 22 during surgery. Examples of non-cardiac surgery may include the use of electrocautery during surgery, lithotripsy, the use of a TENS device, or radiation therapy. Each time the surgeon uses the electrocautery device 66, the control circuit 12 activates the electromagnetic component 10 to generate a magnetic field B over the magnetically-switchable device 22, thus halting or modifying the normal operation of the magnetically-switchable device 22 and preventing a disruption or malfunction due to EMI. This is again shown in Figure 7, in which a simplified circuit diagram of the electrocautery system is shown.

    [0032] As seen in Figure 7, control circuit 12, including a power source 62, is electrically connected to both an electromagnetic component 10 and an electrocautery device 66. When the electrocautery device 66 is in use during an operation, the circuit loop closes, thus connecting the control circuit 20, the electromagnetic component 10 and the electrocautery device 66 in series. This connection enables the power source 62 to transmit a current I to the electromagnetic component 10 for generation of a magnetic field B. When the electrocautery device 66 is not in use, the loop remains open and no current I may pass to the electromagnetic component 10.

    [0033] The control circuit 12 may optionally include a protective circuit 70 to prevent electrical shock generated while turning the electrocautery device 66 on and off. The protective circuit 70 may be positioned between the power source 62 and the electrocautery device 66 and/or switch 26. Alternatively, the protective circuit may be positioned between the electrocautery device 66 and/or switch 26 and the electromagnetic component 10.

    [0034] According to one embodiment, the electrocautery system 600 may include a lock-out at ten seconds or some other programmable period of time to prevent an accidental reprogramming of an ICD. Some ICD models reprogram if a magnet is applied for more than several seconds. This embodiment may be able to control the duration of the magnet application in such a case or leave this setting off if reprogramming is not an obstacle. In addition, it is possible that the electromagnet may generate too much heat and such a lock-out system may set a duration of the electromagnetism to prevent this.

    [0035] According to another embodiment, either the magnetic switching device 100 or the electrocautery system 600 (not part of the invention) may include a lighting device or LED device to show a user, for example a surgeon, that the electromagnetic component 10 is in use.

    [0036] According to a further embodiment, the electrocautery device 66 may be directly plugged into the control circuit 12 of the electrocautery system 600. Since the electrocautery device 66 may act as the electrocautery system 600 on/off switch, according to one embodiment the electrocautery device 66 should plug into the electrocautery system 600 prior to operation.

    [0037] Figure 8 is a schematic diagram of the electrocautery system 600, not being part of the invention. A ground patch 80 may be coupled to the patch 14 to ground the object 20, i.e. the patient during surgery. The ground patch 80 may be a separate pad connected to a bypass, which may be positioned on an extremity of the object 20 and away from the patch 14 of the electromagnetic component 10. The ground patch 80, , need not be incorporated with the bypass.

    [0038] Figure 9 is a schematic diagram of the magnetic switching device 100 having a plurality of coils 11 connected in series to a power source 24. In this embodiment, five coils 11 are connected via wire 18 to power source 24. The coils 11 may each be coupled to and/or positioned on the patch 14 and may have, for example, a radius R of 4.2 centimeters. The coils 11 may be positioned at a distance S from one another, which may be, for example, 0.2 centimeters apart. The plurality of coils 11 may concentrate a stronger and more directed magnetic field B on the magnetically-switchable device 22. The plurality of coils 11 may increase the tolerance to compensate in the case where the center of the magnetically-switchable device 22 is unknown or where the magnetically-switchable device 22 shifts within object 20 due to body movement during surgery.

    [0039] Figure 10 is a schematic diagram of the magnetic switching device 100 having a plurality of coils 11 connected in parallel to a plurality of power sources 24. In this embodiment, five coils 11 are positioned on or coupled to the patch 14 of the electromagnetic component 10. Each coil 11 is connected to a separate power source 24. Each coil 11 may further be connected to a separate trigger and/or switch 26. The power sources 24 may optionally be external power sources to the system. A connecting module (not shown) may be used to correlate the operation of each coil 11 of the magnetic switching device 100. Here again, the coils 11 may have a radius R, for example 4.2 centimeters, and may be positioned at a distance S from one another, for example 0.2 centimeters. The plurality of coils 11 may increase the tolerance to compensate in the case where the center of the magnetically-switchable device 22 is unknown or where the magnetically-switchable device 22 shifts within object 20 due to body movement during surgery.

    [0040] According to a further embodiment, a hybrid system may be used (not shown). The hybrid system may use both an electromagnetic coil 11 and a permanent magnet to generate a magnetic field B of sufficient strength and orientation to engage a switch in the magnetically-switchable device 22 of the object 20. In this embodiment, a thinly sliced static or permanent magnet may be combined with an electromagnet coil 11 to produce a more powerful magnetic field B over the magnetically-switchable device 22. Meanwhile, the magnetic field B generated only by the static or permanent magnet may be smaller than 800 µT (eight Gauss) so that it cannot turn on the magnetically-switchable device 22 of the object 20, unless the coil 11 is activated. The permanent magnet may either be looped together with the electromagnet coil 11 using wire 18 or may be layered on top of the electromagnet coil 11. This embodiment may reduce the amount of electricity needed to effectively operate the electromagnetic component 10 of the magnetic switching device 100.


    Claims

    1. A magnetic switching device, comprising:

    an electromagnetic component sufficiently compact to be placed on or proximate to an exterior surface of a patient comprising a magnetically-switchable device therein; and

    a control circuit electrically connected to the electromagnetic component, wherein the electromagnetic component is constructed to generate a magnetic field of sufficient strength and orientation to engage a switch in the magnetically-switchable device, characterized in that the control circuit comprises a power supply coupled to a switch which is adapted to trigger activation of the electromagnetic component, wherein the switch comprises a switch of an electrocautery pen.


     
    2. The magnetic switching device of claim 1, wherein the electromagnetic component comprises an adhesive patch adapted to be affixed to the exterior surface of the patient.
     
    3. The magnetic switching device of claim 1, wherein the magnetically-switchable device comprises a pacemaker or an implantable cardioverter-defibrillator.
     
    4. The magnetic switching device of claim 1, wherein the electromagnetic component includes a lighting device adapted to indicate whether the electromagnetic component is generating the magnetic field.
     
    5. The magnetic switching device of claim 1, wherein the magnetic field generated by the electromagnetic component is between 10-4500 µT (0.1-45 Gauss).
     
    6. The magnetic switching device of claim 1, wherein the electromagnetic component comprises an electromagnetic coil having at least one turn.
     
    7. The magnetic switching device of claim 1, wherein the electromagnetic component comprises an electromagnetic coil defining a hollow space therein.
     


    Ansprüche

    1. Magnetschaltervorrichtung, umfassend:

    eine elektromagnetische Komponente, die ausreichend kompakt ist, um sie auf oder in der Nähe einer Außenfläche eines Patienten zu platzieren, und eine magnetisch schaltbare Vorrichtung beinhaltet; und

    eine Steuerungsschaltung, die elektrisch an die elektromagnetische Komponente angeschlossen ist,

    wobei die elektromagnetische Komponente so aufgebaut ist, dass sie ein Magnetfeld ausreichender Stärke und Ausrichtung erzeugt, um auf einen Schalter in der magnetisch schaltbaren Vorrichtung einzuwirken, dadurch gekennzeichnet, dass die Steuerungsschaltung eine Stromquelle umfasst, die an einen Schalter gekoppelt ist, der geeignet ist, eine Aktivierung der elektromagnetischen Komponente auszulösen, wobei der Schalter einen Schalter eines Elektrokauters umfasst.


     
    2. Magnetschaltervorrichtung gemäß Anspruch 1, wobei die elektromagnetische Komponente ein Klebepflaster umfasst, das auf der Außenfläche des Patienten befestigt werden kann.
     
    3. Magnetschaltervorrichtung gemäß Anspruch 1, wobei die magnetisch schaltbare Vorrichtung einen Herzschrittmacher oder einen implantierbaren Kardioverter-Defibrillator umfasst.
     
    4. Magnetschaltervorrichtung gemäß Anspruch 1, wobei die elektromagnetische Komponente eine Beleuchtungsvorrichtung umfasst, die anzeigen kann, ob die elektromagnetische Komponente das Magnetfeld erzeugt.
     
    5. Magnetschaltervorrichtung gemäß Anspruch 1, wobei das durch die elektromagnetische Komponente erzeugte Magnetfeld eine Feldstärke von 10-4500 µT (0,1-45 Gauss) aufweist.
     
    6. Magnetschaltervorrichtung gemäß Anspruch 1, wobei die elektromagnetische Komponente eine elektromagnetische Spule mit wenigstens einer Windung umfasst.
     
    7. Magnetschaltervorrichtung gemäß Anspruch 1, wobei die elektromagnetische Komponente eine elektromagnetische Spule umfasst, in der ein Hohlraum definiert ist.
     


    Revendications

    1. Dispositif de commutation magnétique, comprenant :

    un composant électromagnétique suffisamment compact pour être placé sur ou à proximité d'une surface extérieure d'un patient comprenant un dispositif magnétiquement commutable à l'intérieur ; et

    un circuit de commande connecté électriquement au composant électromagnétique,

    dans lequel le composant électromagnétique est construit pour générer un champ magnétique d'intensité et d'orientation suffisantes pour s'engager avec un commutateur dans le dispositif magnétiquement commutable, caractérisé en ce que le circuit de commande comprend une alimentation électrique couplée à un commutateur qui est adapté pour déclencher une activation du composant électromagnétique, dans lequel le commutateur comprend un commutateur d'un stylo d'électrocautérisation.


     
    2. Dispositif de commutation magnétique selon la revendication 1, dans lequel le composant électromagnétique comprend un timbre adhésif adapté pour être apposé sur la surface extérieure du patient.
     
    3. Dispositif de commutation magnétique selon la revendication 1, dans lequel le dispositif magnétiquement commutable comprend un stimulateur cardiaque ou un défibrillateur-cardioverteur implantable.
     
    4. Dispositif de commutation magnétique selon la revendication 1, dans lequel le composant électromagnétique inclut un dispositif d'éclairage adapté pour indiquer si le composant électromagnétique génère le champ magnétique.
     
    5. Dispositif de commutation magnétique selon la revendication 1, dans lequel le champ magnétique généré par le composant électromagnétique est entre 10 et 4500 µT (0,1 à 45 gauss).
     
    6. Dispositif de commutation magnétique selon la revendication 1, dans lequel le composant électromagnétique comprend une bobine électromagnétique ayant au moins une spire.
     
    7. Dispositif de commutation magnétique selon la revendication 1, dans lequel le composant électromagnétique comprend une bobine électromagnétique définissant un espace creux à l'intérieur.
     




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    Cited references

    REFERENCES CITED IN THE DESCRIPTION



    This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.

    Patent documents cited in the description