Safety optimization in microprocessor controlled implantable devices
First Claim
1. An implantable cardiac stimulating device comprising:
- a microprocessor;
a memory device coupled to the microprocessor;
a pulse delivery circuit, coupled to the microprocessor, for delivering an electrical stimulation pulse to a patient'"'"'s heart;
a backup pacing circuit for delivering backup pacing to the patient'"'"'s heart;
at least one error detection circuit for detecting errors in the implantable cardiac stimulating device; and
switching circuitry, coupled to each of the microprocessor, the at least one error detection circuit, and the backup pacing circuit, for switching the implantable cardiac stimulating device from a normal mode to an intermediate mode in response to a first error detected by the at least one error detection circuit, and for switching the implantable cardiac stimulating device from the intermediate mode to a backup pacing mode in response to a second error detected by the at least one error detection circuit;
wherein;
while the implantable cardiac'"'"'stimulating device is in the normal mode, the pulse delivery circuit is controlled by the microprocessor, and the microprocessor is able to store data in and retrieve data from the memory device;
while the implantable cardiac stimulating device is in the intermediate mode, the pulse delivery circuit is controlled by the microprocessor, the microprocessor is able to store data in the memory device, and the microprocessor is able to retrieve data that have been stored in the memory device after the implantable cardiac stimulating device entered the intermediate mode; and
while the implantable cardiac stimulating device is in the backup pacing mode, the backup pacing circuit is activated.
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Accused Products
Abstract
A microprocessor-controlled implantable cardiac stimulating device having a normal mode, an intermediate mode, and a backup pacing mode is provided. The device switches from one mode to another in response to the detection of any one of an address error, parity error, opcode error, or watchdog timer error. The microprocessor is shut down during the delivery of a cardioversion or defibrillation shock in order to prevent signals produced by the microprocessor from being subjected to transient electrical signals. The interrupt registers of the microprocessor are also disabled during the delivery of a cardioversion or defibrillation shock. In an alternative embodiment, an implantable cardiac stimulating device is provided with redundant microprocessors in order to detect malfunctions of the microprocessors.
61 Citations
22 Claims
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1. An implantable cardiac stimulating device comprising:
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a microprocessor; a memory device coupled to the microprocessor; a pulse delivery circuit, coupled to the microprocessor, for delivering an electrical stimulation pulse to a patient'"'"'s heart; a backup pacing circuit for delivering backup pacing to the patient'"'"'s heart; at least one error detection circuit for detecting errors in the implantable cardiac stimulating device; and switching circuitry, coupled to each of the microprocessor, the at least one error detection circuit, and the backup pacing circuit, for switching the implantable cardiac stimulating device from a normal mode to an intermediate mode in response to a first error detected by the at least one error detection circuit, and for switching the implantable cardiac stimulating device from the intermediate mode to a backup pacing mode in response to a second error detected by the at least one error detection circuit;
wherein;while the implantable cardiac'"'"'stimulating device is in the normal mode, the pulse delivery circuit is controlled by the microprocessor, and the microprocessor is able to store data in and retrieve data from the memory device; while the implantable cardiac stimulating device is in the intermediate mode, the pulse delivery circuit is controlled by the microprocessor, the microprocessor is able to store data in the memory device, and the microprocessor is able to retrieve data that have been stored in the memory device after the implantable cardiac stimulating device entered the intermediate mode; and while the implantable cardiac stimulating device is in the backup pacing mode, the backup pacing circuit is activated. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. A method of operating an implantable cardiac stimulating device, the implantable cardiac stimulating device including a pulse delivery circuit for delivering electrical stimulation pulses to a patient'"'"'s heart, a microprocessor, a memory device, at least one error detection circuit for detecting errors in the implantable cardiac stimulating device, and a backup pacing circuit for delivering backup pacing to the patient'"'"'s heart, the method comprising the steps of:
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providing a normal mode of operation for the implantable cardiac stimulating device in which the pulse delivery circuit is controlled by the microprocessor, wherein the microprocessor is able to store data in and retrieve data from the memory device; providing an intermediate mode of operation for the implantable cardiac stimulating device in which the pulse delivery circuit is controlled by the microprocessor, the microprocessor is able to store data in the memory device, and the microprocessor is able to retrieve data that have been stored in the memory device after the implantable cardiac stimulating device has entered the intermediate mode; providing a backup pacing mode of the implantable cardiac stimulating device in which the backup pacing circuitry is activated; and switching the implantable cardiac stimulating device from the normal mode to the intermediate mode in response to a first error detected by the at least one error detection circuit, and switching the implantable cardiac stimulating device from the intermediate mode to the backup pacing mode in response to a second error detected by the at least one error detection circuit. - View Dependent Claims (17, 18, 19, 20, 21, 22)
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Specification