Physician interface expert system for programming implantable arrythmia treatment devices

#The present invention is related to programmable implantable cardioverter defibrillators (ICDs). In particular, the present invention is an expert system for programming ICDs such that a first set of values may be entered by a physician into a programmer and a second set of values are then transmitted from the programmer to the ICD.

#The use of implantable cardioverter defibrillator (ICD) systems as a medical therapy for persons with abnormal heart conditions or cardiac arrhythmias is well known. Initially, ICD systems were used only to resuscitate or defibrillate a heart which had stopped pumping because there was no organized heart beat. This type of arrhythmia, referred to as ventricular fibrillation (VF), is relatively simple to detect and is fatal if not corrected in a few minutes. The general approach in using ICD systems to treat ventricular fibrillation is to deliver a relatively large electrical defibrillation countershock to electrodes implanted about the heart in an attempt to restart the electrical activity of the heart. In existing ICD systems, the defibrillation electrical countershocks are in the range of 25 to 40 joules, and are generated by high voltage capacitors within the ICD system that are charged to approximately 600 to 750 volts by one or more internal batteries.

#ICD systems are now being used to treat other types of abnormal heart conditions, such as the main pumping chambers of the heart beating too fast. This type of arrhythmia, referred to as ventricular tachycardia (VT) can be clinically divided into two subclasses. The first VT subclass is a low rate ventricular tachycardia where the heart is beating in the range of approximately 120 to about 180 beats per minute. While a low rate VT is not normal, the patient is not in immediate danger of dying because there is still a perfusing pulse that can pump blood to the body. The second VT subclass is a high rate ventricular tachycardia where the heart is beating in the range of approximately 180 to about 250 beats per minute. In contrast to low rate VT, a patient with a high rate VT is in imminent danger of death within the next several minutes due to a significantly diminished or absent perfusing pulse.

#FIG. 1 is a schematic illustration of an implantable cardiac defibrillator system having a housing portion implanted in a patient and an operator interface device external the patient.

#FIG. 2 is a block diagram of the housing and the programmer of FIG. 1.

#FIGS. 3A and 3B are a flow chart of a method of operation of the present invention.

#The present invention is a physician interface expert system. The expert system is designed to allow a physician who is familiar with a patient's medical history to program at least one parameter into an implantable cardioverter defibrillator (ICD) without having to know each and every parameter necessary for programming the ICD and without having to convert into the units of the parameters stored within the ICD.

#A programmable ICD system is illustrated generally at 10 in FIG. 1. The system has an implantable ICD portion 12 and a programming portion 14 external to the patient. The ICD portion 12 has a housing 16 with a header 18 mounted to the housing, and at least one electrical lead 20 connected to header 18. As illustrated in FIG. 1, electrical lead 20 may be positioned inside the patient's heart 22. ICD 12 is a standard ICD containing pulse generating circuitry, control circuitry including parameter storage and a receiver, none of which are illustrated in FIG. 1, but may be seen schematically in FIG. 2.

#Programming device 14 comprises an input device 24, an operator interface device 26 and a transmitter 28. The input device in the present invention is illustrated as a keyboard, but other known interface devices may also be used without departing from the spirit or scope of the invention. Likewise, while a monitor is illustrated as operator interface device 26, other such devices for outputting information to an operator could also be used, such as a printer, without departing from the spirit or scope of the invention. Transmitter 28 is a low powered remote signal transmitter for transmitting information from programming device 14 to ICD 12.