Francis M Charbonnier

US Patent:

43288081, May 11, 1982

Filed:

Oct 9, 1980

Appl. No.:

6/195558

Inventors:

Francis M. Charbonnier - McMinnville OR
Paul V. Long - McMinnville OR

Assignee:

Hewlett-Packard Company - Palo Alto CA

International Classification:

A61N 136

US Classification:

128419D

Abstract:

A defibrillator apparatus applies defibrillation a shock pulse to a patient at a selected energy level. The peak current magnitude of the pulse is sensed and processed to produce an indication of the value of transthoracic load resistance presented by the patient during the pulse. Also produced is an indication of the energy actually delivered to the patient by the defibrillation pulse. An alarm is activated when patient transthoracic resistance exceeds a predetermined value, thereby to warn the operator to take corrective action before again attempting defibrillation.

US Patent:

51118130, May 12, 1992

Filed:

May 18, 1990

Appl. No.:

7/526412

Inventors:

Francis M. Charbonnier - McMinnville OR
Martin G. Rockwell - Sherwood OR

Assignee:

Hewlett-Packard Company - Palo Alto CA

International Classification:

A61N 139

US Classification:

128419D

Abstract:

Impedance-normalized delivered energy is used as a control parameter in a defibrillation methodolgy and can be selected to yield the highest probability of successful defibrillation while minimizing the risk of damage to the myocardium and nerve system. This control parameter is essentially independent of patient transthoracic impedance and of discharge pulse waveform and duration, thereby making it advantageous as a standard on which a universal defibrillation protocol may be based.

US Patent:

48401773, Jun 20, 1989

Filed:

Nov 3, 1987

Appl. No.:

7/117125

Inventors:

Francis M. Charbonnier - McMinnville OR
Martin G. Rockwell - Sherwood OR
Carl E. Benvegar - Corvallis OR

Assignee:

Hewlett-Packard Company - Palo Alto CA

International Classification:

A61N 136

US Classification:

128419D

Abstract:

A method and apparatus is disclosed for providing to the body of a patient a defibrillation pulse having a magnitude calculated to induce in that particular patient a desired defibrillation current. The patient's response to a defibrillation pulse is characterized in advance of defibrillation by repeatedly sampling the patient's transthoracic impedance to a small alternating current excitation signal. The sample having the lowest magnitude is taken to represent the patient's true transthoracic impedance. This lowest sampled impedance value is normalized to take into account the shape of the expected waveform and is then multiplied by the desired current to yield the target charge level to which an energy storage device must be charged to induce the desired current to flow in the patient on discharge. Charging of the energy storage device desirably begins before measurement of transthoracic impedance is completed and continues until the target charge is reached. Discharge of an energy storage device so charged causes the desired current to flow through the patient.