초록 ▼

An implantable medical device may have a circuit failure mode. The disclosed circuit may have an integrated failure point designed to fail prior to those portions of the circuit. The integrated failure point may include a narrowed portion of a high voltage lead and a grounded lead having a narrow ga

An implantable medical device may have a circuit failure mode. The disclosed circuit may have an integrated failure point designed to fail prior to those portions of the circuit. The integrated failure point may include a narrowed portion of a high voltage lead and a grounded lead having a narrow gap separating the grounded lead from the narrowed portion of the high voltage lead. During a high stress fault condition the narrowed portion of the high voltage lead acts as a fuse, forming a vaporized cloud of metal, which shorts current in the high voltage lead across the narrow gap to the grounded lead, thus protecting the remaining portion of the circuit from the high stress condition.

대표청구항 ▼

1. A method, comprising: delivering defibrillation shock energy from an implantable shock therapy energy storage capacitor to a subject through an electrical circuit disposed on at least one of printed wiring board, a hybrid circuit board, or an integrated circuit device;in response to the delivered

1. A method, comprising: delivering defibrillation shock energy from an implantable shock therapy energy storage capacitor to a subject through an electrical circuit disposed on at least one of printed wiring board, a hybrid circuit board, or an integrated circuit device;in response to the delivered defibrillation shock energy exceeding a threshold, triggering a plasma switch to switch into shunting the defibrillation shock energy being delivered from the capacitor away from the electrical circuit and to at least one of a circuit power or ground node, including vaporizing material to form a cloud of vaporized material to form an electrical conduction path from the electrical circuit to the node, wherein the cloud is to bridge a nonconductive gap between the electrical circuit and the node, the gap having a dimension selected to be within the cloud of vaporized material. 2. The method of claim 1, wherein shunting the capacitor shock therapy energy away from the electrical circuit includes using at least one of a plurality of resistors, a fuse, a transistor, a Hall effect switch, a magnetic switch, a microswitch or a solenoid to open an electrical connection to the electrical circuit and close an electrical connection to the node. 3. The method of claim 2, wherein the material comprises the fuse. 4. The method of claim 3, wherein the fuse forms is disposed between the capacitor and the electrical circuit and is selected to heat to a vaporization temperature at the threshold. 5. The method of claim 1, comprising shunting the capacitor shock therapy energy away from the electrical circuit using the plasma switch to open an electrical connection to the electrical circuit and close an electrical connection to the ground node. 6. The method of claim 1, further comprising selecting the threshold by selecting a fuse material, a fuse material vaporization temperature, a fuse cross sectional area, a fuse length, and a fuse resistance to cause a fuse connected between the capacitor and the electrical circuit to heat to the fuse vaporization temperature at the threshold, to vaporize the fuse and form an open conductor to the electrical circuit. 7. The method of claim 6, further comprising forming a nonconductive gap between the fuse material and the electrical connection to the node, the gap having a dimension selected to be within a cloud of vaporized fuse material from the delivered defibrillation shock energy exceeding the threshold, and forming an electrical conduction path to the node with the cloud. 8. The method of claim 1, comprising detecting an electrical overstress condition in the electrical circuit and in response to detecting the electrical overstress condition, triggering the plasma switch. 9. A method of using an implantable medical device, comprising: determining a present condition of a patient having an implantable medical device implanted within the patient;evaluating the present condition and determining whether to initiate a course of shock therapy;delivering defibrillation shock energy from an implantable shock therapy energy storage capacitor to a subject through an electrical circuit; andin response to the delivered defibrillation shock energy exceeding a threshold, triggering a plasma switch to switch into shunting the defibrillation shock energy being delivered from the capacitor away from the electrical circuit and to a circuit power or ground node, wherein shunting the defibrillation shock energy includes forming the plasma switch from fuse vapor of a burned fuse in electrical communication with the capacitor. 10. The method of using of claim 9, comprising forming the plasma switch between an end of the fuse located nearest the shock therapy energy storage capacitor and the ground electrical connection. 11. The method of claim 9, wherein the fuse is disposed between the capacitor and the electrical circuit and the fuse vapor is to bridge a nonconductive gap between the fuse and the node, the gap having a dimension selected to be within the cloud of vaporized material. 12. A method, comprising: forming an implantable medical device circuit, for providing a defibrillation shock energy, on at least one of a printed wiring board, a hybrid circuit board, or an integrated circuit device;forming a fuse between a capacitor and the medical device circuit; andforming a plasma switch between the fuse and a ground source;wherein the plasma switch is for, in response to the defibrillation shock energy being delivered from implantable medical device circuit and exceeding a threshold, triggering a disconnecting of the capacitor from the medical device circuit and for triggering an at least temporary connecting of the capacitor to the ground source,wherein the plasma switch is for shunting the defibrillation shock energy being delivered from the capacitor away from the electrical circuit and to a circuit power or ground node, wherein shunting the defibrillation shock energy includes forming the plasma switch from fuse vapor of a burned fuse in electrical communication with the capacitor. 13. The method of claim 12, wherein forming the plasma switch includes locating a portion of an electrical conductor connected to the ground source close to at least one of a portion of the fuse and a portion of a second electrical conductor connecting the capacitor and the fuse. 14. The method of claim 13, wherein forming the plasma switch includes locating a portion of the electrical conductor connected to the ground source close to the portion of the fuse. 15. The method of claim 13, wherein the fuse forms a part of the electrical circuit and comprising selecting at least one of a distance between the electrical conductor connected to the ground source and the portion of the fuse, a material of the fuse, a thickness of the fuse, a length of the fuse, a width of the fuse, a resistance of the fuse and a capacitor voltage level to select the threshold for triggering the plasma switch. 16. The method of claim 15, comprising selecting the distance between the electrical conductor connected to the ground source and the portion of the fuse to select the threshold. 17. The method of claim 15, comprising selecting a property of at least a portion of the fuse to vaporize as a cloud of ions in response to the delivered defibrillation shock energy exceeding a threshold. 18. The method of claim 17, comprising selecting the distance between the electrical conductor connected to the ground source and the fuse to be substantially equal to a minimum design rule space for two unconnected metal features on a printed circuit board, a hybrid and an integrated circuit. 19. The method of claim 12, wherein forming an implantable medical device circuit on at least one of a printed wiring board, a hybrid circuit board, and an integrated circuit device includes forming a hole in a dielectric of at least one of a printed wiring board, a hybrid circuit board, and an integrated circuit device, with the fuse disposed over the hole. 20. The method of claim 12, comprising forming the implantable medical device circuit on the printed wiring board. 21. A method, comprising: delivering defibrillation shock energy from an implantable shock therapy energy storage capacitor to a subject through an electrical circuit;in response to the delivered defibrillation shock energy exceeding a threshold, triggering a plasma switch to switch into shunting the defibrillation shock energy being delivered from the capacitor away from the electrical circuit and to a circuit power or ground node;selecting the threshold by selecting a fuse material, a fuse material vaporization temperature, a fuse cross sectional area, a fuse length, and a fuse resistance to cause a fuse connected between the capacitor and the electrical circuit to heat to the fuse vaporization temperature at the threshold, to vaporize the fuse and form an open conductor to the electrical circuit; andforming a nonconductive gap between the fuse material and the electrical connection to the node, the gap having a dimension selected to be within a cloud of vaporized fuse material from the delivered defibrillation shock energy exceeding the threshold; andforming an electrical conduction path to the node with the cloud. 22. A method of using an implantable medical device, comprising: determining a present condition of a patient having an implantable medical device implanted within the patient;evaluating the present condition and determining whether to initiate a course of shock therapy;delivering defibrillation shock energy from an implantable shock therapy energy storage capacitor to a subject through an electrical circuit; andin response to the delivered defibrillation shock energy exceeding a threshold, triggering a plasma switch to switch into shunting the defibrillation shock energy being delivered from the capacitor away from the electrical circuit and to a circuit power or ground node, wherein shunting the shock therapy energy to the energy sink includes shunting to the node, wherein shunting the shock therapy energy to the node includes burning out a fuse located between the shock therapy energy storage capacitor and the electrical circuit.