Method and system for radiofrequency ablation of cardiac tissue

• US 5,584,830 A
• Filed: 03/30/1994
• Issued: 12/17/1996
• Est. Priority Date: 03/30/1994
• Status: Expired due to Term

• Current Assignee: Medtronic Cardiorhythm
• Original Assignee: Medtronic Cardiorhythm
• Inventors: Cox, Clifford C., Ladd, Kevin C.
• Primary Examiner(s): Cohen, Lee S.
• Application Number:
  US08/220,135
• Time in Patent Office: 993 Days
• Field of Search: 607/101, 607/102, 607/122, 607/98, 607/99, 606/42, 606/41, 606/49, 606/31, 606/34, 606/40, 128/736
• US Class Current: 606/34
• CPC Class Codes: A61B 18/1206 Generators therefor
• CPC Class Codes: A61B 18/1492 having a flexible, catheter-like structure, e.g. for heart ablation A61B18/1477 takes precedence
• CPC Class Codes: A61B 2017/003 Steerable
• CPC Class Codes: A61B 2017/00725 Calibration or performance testing
• CPC Class Codes: A61B 2018/00357 Endocardium
• CPC Class Codes: A61B 2018/00577 Ablation
• CPC Class Codes: A61B 2018/00666 using a threshold value
• CPC Class Codes: A61B 2018/00678 upper
• CPC Class Codes: A61B 2018/00702 Power or energy
• CPC Class Codes: A61B 2018/00708 switching the power on or off
• CPC Class Codes: A61B 2018/00791 Temperature
• CPC Class Codes: A61B 2018/00821 measured by a thermocouple
• CPC Class Codes: A61B 2018/00827 Current
• CPC Class Codes: A61B 2018/00839 Bioelectrical parameters, e.g. ECG, EEG
• CPC Class Codes: A61B 2018/00875 Resistance or impedance
• CPC Class Codes: A61B 2018/00892 Voltage
• CPC Class Codes: A61B 2018/1226 powered by a battery
• CPC Class Codes: A61B 2018/1253 monopolar
• CPC Class Codes: A61N 1/403 for thermotherapy, e.g. hyperthermia

Abstract

A system for checking the initial calibration of a temperature measuring device that provides a temperature measuring signal in a catheter includes a comparison unit for comparing the magnitude of the temperature signal to a reference value indicating the normal body temperature of the patient. The treatment procedure is disabled if the magnitude of the temperature signal is not within a predetermined range of the reference value.

Claims

1. In a method for using a patient treatment device for insertion in the body of a patient that utilizes a temperature measuring device to control a procedure where a temperature output signal having a magnitude indicating the magnitude of the temperature is output by the temperature measuring device, the improvement comprising a method for preventing injury in the event that the temperature measuring device is incorrectly operating, said method for preventing comprising the steps of:

providing a reference value, stored in said device, having a magnitude of about 37°

C. which indicates a normal body temperature of a patient;

comparing the temperature output signal to the reference value to determine whether the magnitude of the temperature output signal differs from the magnitude of the reference value by more that a predetermined amount;

disabling the patient treatment device if the magnitude of the temperature output signal differs from the magnitude of the reference value by more than a predetermined amount.

2. In a patient treatment device for insertion in the body of a patient that utilizes a temperature measuring device to control a procedure where a temperature output signal having a magnitude indicating the magnitude of the temperature is output by the temperature measuring device, the improvement comprising a system for preventing injury in the event that the temperature measuring device is incorrectly operating, said system comprising:

means for storing a reference value having a magnitude of about 37°

C. which indicates a normal body temperature of a patient;

means, coupled to said means for storing and to receive said temperature output signal, for comparing the temperature output signal to the reference value to determine whether the magnitude of the temperature output signal differs from the magnitude of the reference value by more than a predetermined amount;

means, responsive to said means for comparing, for disabling the patient treatment device if the magnitude of the temperature output signal differs from the magnitude of the reference value by more than a predetermined amount.

3. In a patient treatment device for insertion in the body of a patient that utilizes a temperature measuring device to control a procedure, where a temperature output signal, having a magnitude indicating the magnitude of the actual body temperature of the patient, is output by the temperature measuring device, the improvement comprising a system for preventing injury in the event that the temperature measuring device is incorrectly operating, said system comprising:

a convertor for converting the magnitude of the temperature output signal to a digital temperature value;

a memory for storing a digital comparison value having a magnitude of about 37°

C. which indicates the normal body temperature of a patient;

processor means, coupled to said convertor and said memory, for processing said digital temperature value and said digital comparison value to determine whether the magnitude of the temperature output signal indicates a temperature within a predetermined range of the normal body temperature of the patient and for disabling the patient treatment device if the indicated temperature is outside the predetermined range.