External power source for an implantable medical device having an adjustable magnetic core and system and method related therefore

{
  "publication_number": "US2005075700A1",
  "country": "US",
  "kind": "A1",
  "title": "External power source for an implantable medical device having an adjustable magnetic core and system and method related therefore",
  "abstract": "External power source, and system and method using such external power source, for an implantable medical device having therapeutic componentry and a secondary coil operatively coupled to the therapeutic componentry. A primary coil is capable of inductively energizing the secondary coil when externally placed in proximity of the secondary coil. A repositionable magnetic core associated with the primary coil is capable of being repositioned by a user of the external power source. An indicator is capable of providing the user with information relative to coupling between the primary coil and the secondary coil as a function of repositioning of the repositionable magnetic core.",
  "claims": [
    "1. An external power source for an implantable medical device having therapeutic componentry and a secondary coil operatively coupled to said therapeutic componentry, comprising: a primary coil capable of inductively energizing said secondary coil when externally placed in proximity of said secondary coil; a repositionable magnetic core associated with said primary coil capable of being repositioned by a user of said external power source; and an indicator capable of providing said user with information relative to coupling between said primary coil and said secondary coil as a function of repositioning of said repositionable magnetic core.",
    "2. An external power source as in claim 1 further comprising: a housing containing said primary coil and said repositionable magnetic core; and a non-magnetic retainer holding said magnetic core in said housing.",
    "3. An external power source as in claim 1 wherein said repositionable magnetic core comprises a circular ferrite disc, having a thickness, positioned inside said primary coil and an off-center ferrite post having a thickness greater than said thickness of said circular ferrite disc.",
    "4. An external power source as in claim 1 wherein said magnetic core is a ferrite core.",
    "5. A charger for an implantable medical device having a rechargeable power source and a secondary charging coil operatively coupled to said rechargeable power source, comprising: a primary charging coil capable of inductively energizing said secondary coil when externally placed in proximity of said secondary coil; a repositionable magnetic core associated with said primary coil capable of being repositioned by a user of said charger; and an indicator capable of providing said user with information relative to coupling between said primary coil and said secondary coil as a function of repositioning of said repositionable magnetic core.",
    "6. A charger as in claim 5 further comprising: a housing containing said primary coil and said repositionable magnetic core; and a non-magnetic retainer holding said magnetic core in said housing.",
    "7. A charger as in claim 5 wherein said repositionable magnetic core comprises a circular ferrite disc, having a thickness, positioned inside said primary coil and an off-center ferrite post having a thickness greater than said thickness of said circular ferrite disc.",
    "8. A charger as in claim 5 wherein said magnetic core is a ferrite core.",
    "9. An external power source for an implantable medical device having therapeutic componentry and a secondary coil operatively coupled to said therapeutic componentry, comprising: a primary coil capable of inductively energizing said secondary coil when externally placed in proximity of said secondary coil; a rotatable magnetic core placed off-center with respect to said primary coil and capable of being rotated by a user of said external power source; and an indicator capable of providing said user with information relative to coupling between said primary coil and said secondary coil as a function of rotating of said rotatable magnetic core.",
    "10. An external power source as in claim 9 further comprising: a housing containing said primary coil and said rotatable magnetic core; and a non-magnetic retainer holding said magnetic core in said housing.",
    "11. An external power source as in claim 9 wherein said rotatable magnetic core comprises a circular ferrite disc, having a thickness, positioned inside said primary coil and an off-center ferrite post having a thickness greater than said thickness of said circular ferrite disc.",
    "12. An external power source as in claim 9 wherein said magnetic core is a ferrite core.",
    "13. A system for transcutaneous energy transfer, comprising: an implantable medical device, comprising: a therapeutic componentry; and a secondary coil operatively coupled to said therapeutic componentry; and an external power source, comprising: a primary coil capable of inductively energizing said secondary coil when externally placed in proximity of said secondary coil; a repositionable magnetic core associated with said primary coil capable of being repositioned by a user of said system; and an indicator capable of providing said user with information relative to coupling between said primary coil and said secondary coil as a function of repositioning of said repositionable magnetic core.",
    "14. A system as in claim 13 further comprising: a housing containing said primary coil and said repositionable magnetic core; and a non-magnetic retainer holding said magnetic core in said housing.",
    "15. A system as in claim 13 wherein said repositionable magnetic core comprises a circular ferrite disc, having a thickness, positioned inside said primary coil and an off-center ferrite post having a thickness greater than said thickness of said circular ferrite disc.",
    "16. A system as in claim 13 wherein said magnetic core is a ferrite core.",
    "17. A system for charging, comprising: an implantable medical device, comprising: a rechargeable power source; and a secondary charging coil operatively coupled to said rechargeable power source; and an external charger, comprising: a primary charging coil capable of inductively energizing said secondary coil when externally placed in proximity of said secondary coil; a repositionable magnetic core associated with said primary coil capable of being repositioned by a user of said charger; and an indicator capable of providing said user with information relative to coupling between said primary coil and said secondary coil as a function of repositioning of said repositionable magnetic core.",
    "18. A system as in claim 17 further comprising: a housing containing said primary coil and said repositionable magnetic core; and a non-magnetic retainer holding said magnetic core in said housing.",
    "19. A system as in claim 17 wherein said repositionable magnetic core comprises a circular ferrite disc, having a thickness, positioned inside said primary coil and an off-center ferrite post having a thickness greater than said thickness of said circular ferrite disc.",
    "20. A system as in claim 17 wherein said magnetic core is a ferrite core.",
    "21. A system for charging, comprising: an implantable medical device, comprising: therapeutic componentry; and a secondary charging coil operatively coupled to said therapeutic componentry; and an external power source, comprising: a primary coil capable of inductively energizing said secondary coil when externally placed in proximity of said secondary coil; a rotatable magnetic core placed off-center inside said primary coil capable of being rotated by a user of said system; and an indicator capable of providing said user with information relative to coupling between said primary coil and said secondary coil as a function of rotating of said rotatable magnetic core.",
    "22. A system as in claim 21 further comprising: a housing containing said primary coil and said rotatable magnetic core; and a non-magnetic retainer holding said magnetic core in said housing.",
    "23. A system as in claim 21 wherein said rotatable magnetic core comprises a circular ferrite disc, having a thickness, positioned inside said primary coil and an off-center ferrite post having a thickness greater than said thickness of said circular ferrite disc.",
    "24. A system as in claim 21 wherein said magnetic core is a ferrite core.",
    "25. A method of transcutaneous energy transfer to a medical device implanted in a patient having a secondary charging coil using an external power source having a primary coil and a magnetic core associated with said primary coil, comprising the steps of: positioning said primary coil externally of said patient in proximity of said secondary coil; then repositioning said magnetic core relative to said primary coil; receiving indication of coupling between said primary coil and said secondary coil; and stopping said repositioning step as a function of said receiving step.",
    "26. A method as in claim 25 wherein said primary coil and said magnetic core are contained in a housing and a non-magnetic retainer holds said magnetic core in said housing.",
    "27. A method as in claim 25 wherein said magnetic core comprises a circular ferrite disc, having a thickness, positioned inside said primary coil and an off-center ferrite post having a thickness greater than said thickness of said circular ferrite disc.",
    "28. A method as in claim 25 wherein said magnetic core is a ferrite core.",
    "29. A method of charging a rechargeable power source of a medical device implanted in a patient, having a secondary charging coil operatively coupled to said rechargeable power source, using an external charger having a primary charging coil and a magnetic core associated with said primary charging coil, comprising the steps of: positioning said primary charging coil externally of said patient in proximity of said secondary charging coil; then repositioning said magnetic core relative to said primary coil; receiving indication of coupling between said primary coil and said secondary coil; and stopping said repositioning step as a function of said receiving step.",
    "30. A method as in claim 29 further comprising the step of affixing said primary coil to said patient.",
    "31. A method as in claim 30 wherein said primary coil and said magnetic core are contained in a housing and wherein a non-magnetic retainer holds said magnetic core in said housing.",
    "32. A method as in claim 30 wherein said magnetic core comprises a circular ferrite disc, having a thickness, positioned inside said primary coil and an off-center ferrite post having a thickness greater than said thickness of said circular ferrite disc.",
    "33. A method as in claim 30 wherein said magnetic core is a ferrite core."
  ],
  "description_excerpt": "This invention relates to implantable medical devices and, in particular, to energy transfer devices, systems and methods for implantable medical devices.\n\nImplantable medical devices for producing a therapeutic result in a patient are well known. Examples of such implantable medical devices include implantable drug infusion pumps, implantable neurostimulators, implantable cardioverters, implantable cardiac pacemakers, implantable defibrillators and cochlear implants. Of course, it is recognized that other implantable medical devices are envisioned which utilize energy delivered or transferred from an external device.\n\nA common element in all of these implantable medical devices is the need for electrical power in the implanted medical device. The implanted medical device requires electrical power to perform its therapeutic function whether it be driving an electrical infusion pump, providing an electrical neurostimulation pulse or providing an electrical cardiac stimulation pulse. This electrical power is derived from a power source.\n\nTypically, a power source for an implantable medical device can take one of two forms. The first form utilizes an external power source that transcutaneously delivers energy via wires or radio frequency energy. Having electrical wires which perforate the skin is disadvantageous due, in part, to the risk of infection. Further, continuously coupling patients to an external power for therapy is, at least, a large inconvenience. The second form utilizes single cell batteries as the source of energy of the implantable medical device.",
  "cpc": [
    "A61N 1/3787",
    "H01F 38/14"
  ],
  "ipc": [
    "A61N 1/378",
    "H01F 38/14"
  ],
  "assignees": [
    "Medtronic Inc"
  ],
  "inventors": [
    "Mark Schommer",
    "William Phillips",
    "David Olson",
    "Andrew Schmeling",
    "Charles Peters",
    "Steven Ahcan",
    "John Forsberg",
    "Michael Elvidge",
    "Michael McMullen"
  ],
  "filing_date": "2004-04-30",
  "publication_date": "2005-04-07",
  "priority_date": "2003-10-02",
  "application_number": "US-83750604-A",
  "family_id": "34396425",
  "cited_by_count": 114,
  "citations": [
    "US3357434A",
    "US3888260A",
    "US4041955A",
    "US4071032A",
    "US4134408A",
    "US4186749A",
    "USRE32947E",
    "US4736747A",
    "US5279292A",
    "US5314453A",
    "US5314457A",
    "US5411537A",
    "US5613935A",
    "US5527348A",
    "US5562714A",
    "US5690693A",
    "US5733313A",
    "US5713939A",
    "US5991664A",
    "US5861019A",
    "US6067474A",
    "US20010045785A1",
    "US6092531A",
    "US20030030342A1",
    "US6331744B1",
    "US5945762A",
    "US6281611B1",
    "US6324430B1",
    "US6178353B1",
    "US6308101B1",
    "US6154677A",
    "US6275737B1",
    "US5948006A",
    "US6516227B1",
    "US6505077B1"
  ]
}