Implantable cardioverter defibrillator having a smaller displacement volume
First Claim
1. An implantable cardioverter defibrillator for subcutaneous positioning within a human patient comprising:
- a sealed housing structure constructed of a biocompatible material and having a displacement volume of less than about 90 cc;
one or more connector port means, each connector port means disposed in a wall of said housing structure for providing electrical connections between an interior space of said housing structure and a corresponding electrode lead within said human patient;
circuit means disposed within said interior space of said housing structure and operably connected to said connector port means for sensing cardiac signals received from one or more of said electrode leads and, in response to the detection of an arrhythmia in said cardiac signals, controlling delivery of one or more high energy electrical cardioversion/defibrillation countershocks of at least 0.5 Joules to the myocardium of said human patient;
capacitor means disposed within said interior space of said housing structure and operably connected to said circuit means for storing electrical energy to generate said electrical cardioversion/defibrillation countershocks and having an effective capacitance value of less than 120 μ
F; and
battery means disposed within said interior space of said housing structure and operably connected to said circuit means and said capacitor means for providing electrical energy to said circuit means and said capacitor means,wherein said battery means and said capacitor means are selected such that a maximum electrical charge energy stored by said capacitor means for each of said electrical cardioversion/defibrillation countershocks is less than about 30 J and said implantable cardioverter defibrillator is capable of delivering at least five of said electrical cardioversion/defibrillation countershocks in a four minute period.
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Accused Products
Abstract
A capacitor-discharge implantable cardioverter defibrillator (ICD) has a relatively smaller displacement volume of less than about 90 cc. The smaller volume of the ICD is achieved by selecting and arranging the internal components of the ICD to deliver a maximum defibrillation countershock optimized in terms of a minimum physiologically effective current (Ipe), rather than a minimum defibrillation threshold energy (DFT). As a result of the optimization in terms of a minimum effective current Ipe, there is a significant decrease in the maximum electrical charge energy (Ec) that must be stored by the capacitor of the ICD to less than about 30 Joules, even though a higher safety margin is provided for by the device. Due to this decrease in the maximum Ec, as well as corollary decreases in the effective capacitance value required for the capacitor and the net energy storage required of the battery, the overall displacement volume of the ICD is reduced to the point where subcutaneous implantation of the device in the pectoral region of human patients is practical. The size of the capacitor is reduced because the effective capacitance required can be less than about 125 μ F. By optimizing both the charging time and the countershock duration for the smaller maximum Ec, the size of the battery is reduced because the total energy storage capacity can be less than about 1.0 Amp-hours. In the preferred embodiment, the charging time for each defibrillation countershock is reduced to less than about 10 seconds and the pulse duration of the countershock is reduced to less than about 6 milliseconds.
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Citations
38 Claims
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1. An implantable cardioverter defibrillator for subcutaneous positioning within a human patient comprising:
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a sealed housing structure constructed of a biocompatible material and having a displacement volume of less than about 90 cc; one or more connector port means, each connector port means disposed in a wall of said housing structure for providing electrical connections between an interior space of said housing structure and a corresponding electrode lead within said human patient; circuit means disposed within said interior space of said housing structure and operably connected to said connector port means for sensing cardiac signals received from one or more of said electrode leads and, in response to the detection of an arrhythmia in said cardiac signals, controlling delivery of one or more high energy electrical cardioversion/defibrillation countershocks of at least 0.5 Joules to the myocardium of said human patient; capacitor means disposed within said interior space of said housing structure and operably connected to said circuit means for storing electrical energy to generate said electrical cardioversion/defibrillation countershocks and having an effective capacitance value of less than 120 μ
F; andbattery means disposed within said interior space of said housing structure and operably connected to said circuit means and said capacitor means for providing electrical energy to said circuit means and said capacitor means, wherein said battery means and said capacitor means are selected such that a maximum electrical charge energy stored by said capacitor means for each of said electrical cardioversion/defibrillation countershocks is less than about 30 J and said implantable cardioverter defibrillator is capable of delivering at least five of said electrical cardioversion/defibrillation countershocks in a four minute period. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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18. An implantable cardioverter defibrillator for subcutaneous positioning within the pectoral region a human patient comprising:
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a sealed housing structure constructed of a biocompatible material and having a displacement volume of less than about 90cc; one or more connector port means, each connector port means disposed in a wall of said housing structure for providing electrical connections between an interior space of said housing structure and a corresponding electrode lead within said human patient; circuit means disposed within said interior space of said housing structure and operably connected to said connector port means for sensing cardiac signals received from one or more of said electrode leads and, in response to the detection of an arrhythmia in said cardiac signals, controlling delivery of one or more electrical cardioversion/defibrillation countershocks of at least 0.5 Joules to the myocardium of said human patient; capacitor means disposed within said interior space of said housing structure and operably connected to said circuit means for storing electrical energy to generate said electrical cardioversion/defibrillation countershocks; and battery means disposed within said interior space of said housing structure and operably connected to said circuit means and said capacitor means for providing electrical energy to said circuit means and said capacitor means, wherein said battery means and said capacitor means are selected to maximize a physiologically effective current (Ipe) for a maximum electrical charge energy (Ec) stored by said capacitor means. - View Dependent Claims (19)
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20. An implantable cardioverter defibrillator for subcutaneous positioning within the pectoral region of a human patient comprising:
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a sealed housing structure constructed of a biocompatible material and having a displacement volume of less than about 90 cc and including one or more connector ports disposed in a wall of said structure for providing electrical connections between an interior space of said structure and electrode leads in said patient; circuit means within said interior space for sensing cardiac signals received from said electrode leads and, in response to the detection of an arrhythmia in said cardiac signals, controlling delivery of one or more electrical cardioversion/defibrillation countershocks of at least 0.5 Joules to said patient; capacitor means within said interior space for storing electrical energy to generate said electrical cardioversion/defibrillation countershocks and having an effective capacitance of less than about 120 μ
F; andbattery means within said interior space for providing electrical energy to said circuit means and said capacitor means and capable of charging said capacitor means in less than about 10 seconds to a maximum electrical charge energy of less than about 30 Joules.
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21. An implantable cardioverter defibrillator for subcutaneous positioning within a pectoral region of a human patient comprising:
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a sealed housing structure constructed of a biocompatible material and having a displacement volume of less than about 90 cc; one or more connector ports, each connector port disposed in a wall of the housing structure for providing electrical connections between an interior space of the housing structure and a corresponding electrical lead that is implanted within the human patient; and circuit means disposed within the interior space of the housing structure and operably connected to the connector ports and responsive to a cardiac signal received from the human patient via one or more of the electrical leads for detecting an arrhythmia in the cardiac signal and, in response, controlling delivery of one or more high energy electrical cardioversion/defibrillation countershocks of at least 0.5 joules to the human patient. - View Dependent Claims (22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38)
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Specification