COMPUTER CONTROLLED DEFIBRILLATOR

• US 3,862,636 A
• Filed: 11/29/1973
• Issued: 01/28/1975
• Est. Priority Date: 01/20/1972
• Status: Expired due to Term

• Current Assignee: Has Medical Incorporated
• Original Assignee: David Bell, William K. Hagan
• Inventors: Bell, David, Hagan, William K.
• Primary Examiner(s): Kamm, William E.
• Application Number:
  US05/420,291
• Time in Patent Office: 425 Days
• Field of Search: 128/419D,419R,421,422,423
• US Class Current: 607/17
• CPC Class Codes: A61N 1/3912 Output circuitry therefor, e.g. switches
• CPC Class Codes: A61N 1/3937 Monitoring output parameters

Abstract

A computer controlled defibrillator comprising a set of electrodes which are engageable with a patient and which are connected to a source of electrical energy by a circuit means. The circuit means comprises storage capacitors, energy selector, computer, manual and reset switches, voltage monitor, current monitor, and output meter. The computer responds to certain external inputs, automatic and manual, and controls the output delivered to the patient. The energy selector permits the selection of the energy which is desired to be delivered to the patient. The sequence is started by closing the manual reset switch which zeroes the output meter and activates the power supply (electrical energy) at a voltage which is dependent on the energy selector. The energy derived from the power supply is stored in the storage capacitors. The energy selector, which is manually set to the energy desired, also feeds an input to the computer. When the manual switch is activated, the computer causes the stored energy source to be connected to the patient through the electrodes. The current monitor and voltage monitor feed instantaneous signals to the computer which computes the energy as a continuous integration process. When the computed energy equals the selected energy, the computer causes the energy source to be disconnected from the patient. The total energy delivered to the patient is indicated as a steady reading on the output meter. A modified form of the defibrillator is also disclosed wherein the magnitude of current in the electrical circuit means may be manually or automatically selected to enable the defibrillator to compensate for the patient'"'"''"'"'s body weight.

Claims

1. A defibrillator comprising in combination, an electrical power source, a set of electrodes engageable with a patient, electrIcal circuit means connecting said power source to said set of electrodes comprising, a computer means, a storage capacitor means for storing energy derived from said power source, an energy selector means for selecting the energy to be delivered to the patient, said energy selector means also feeding an input to said computer means, a switch means for causing the stored energy to be connected to the patient, said switch means being operatively electrically connected to said computer means, a power monitor means for feeding signals to said computer means when said stored energy is delivered to the patient, said computer means computing the energy delivered to the patient and causing the delivery of energy to the patient to be discontinued when the computed energy substantially equals the selected energy, said electrical circuit means also comprising means for selecting the magnitube of current delivered to the patient in accordance with the body weight of the patient.

2. The defibrillator of claim 1 wherein said electrical circuit means includes a variable reference voltage means electrically connected to said storage capacitor means for variably charging said storage capacitor means and wherein said means for selecting the magnitude of current delivered to the patient comprises a second switch means electrically connected to said reference voltage means, said second switch means comprising a variable voltage control.

3. The device of claim 1 wherein said electrical circuit means includes a variable reference voltage means electrically connected to said storage capacitor means for variably charging said storage capacitor means and wherein said means for selecting the magnitude of current delivered to the patient comprises a variable resistor electrically connected to said reference voltage means for varying the voltage in said reference voltage means.

4. The defibrillator of claim 1 wherein said electrical circuit means includes a variable reference voltage means electrically connected to said storage capacitor means for variably charging said storage capacitor means and wherein said means for selecting the magnitude of current delivered to the patient comprises an automatic scaler means electrically connected to said energy selector means and said reference voltage means, said automatic scaler means automatically supplying higher values of current to said variable voltage reference means as higher energy levels are selected for delivery to the patient.

5. The defibrillator of claim 4 wherein said scaler means comprises an amplifier having a predetermined gain so that higher values of current are supplied to said variable voltage reference means as higher energy values are selected for delivery to the patient.