US5111813A
Expired / Lapsed
US
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Defibrillation employing an impedance-corrected delivered energy
Assignee: Koninklijke Philips NV
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Filing: 1990-05-18
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Granted: 1992-05-12
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Expires: 2010-05-18
Abstract
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.
Inventors
- 👤 Francis M. Charbonnier
- 👤 Martin G. Rockwell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 04:45
CPC Classifications
A; A61; A61N; A61N1/00; A61N1/18; A61N1/32; A61N1/38; A61N1/39; A61N1/3925; A61N1/3937
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
87 words
A method of providing a defibrillation pulse to a patient to restore normal cardiac rhythm, the method comprising the steps: establishing a desired value of impedance-corrected delivered energy (E d /Z); measuring a transthoracic impedance Z of the patient; determining the voltage to which a capacitor must be charged to provide the desired value of impedance-corrected delivered energy to a patient having the transthoracic impedance measured; providing charge to or from the capacitor until the calculated voltage is reached; and discharging the charged capacitor through the patient.
Claim 2
Independent Claim
87 words
A method of providing a defibrillation pulse to a patient to restore normal cardiac rhythm, the method comprising the steps: establishing a desired value of impedance-corrected delivered energy (E d /Z); measuring a transthoracic impedance Z of the patient; determining the voltage to which a capacitor must be charged to provide the desired value of impedance-corrected delivered energy to a patient having the transthoracic impedance measured; providing charge to or from the capacitor until the calculated voltage is reached; and discharging the charged capacitor through the patient.
Claim 3
Dependent Claim
32 words
The method of claim 1 which includes charging the capacitor prior to measuring the transthoracic impedance of the patient, and subsequently dumping charge from the capacitor until the calculated voltage is reached.
Claim 4
Dependent Claim
26 words
The method of claim 1 which includes establishing a desired value of impedance-corrected delivered energy (E d Z) without reference to particular characteristics of the patient.
Claim 5
Dependent Claim
18 words
The method of claim 3 which includes establishing a desired value of impedance-corrected delivered energy of 3 Joules/Ohm.
Claim 6
Dependent Claim
57 words
The method of claim 4 which further includes: repeating the charging and discharging steps if the patient's normal cardiac rhythm is not restored by the first discharge; and establishing a desired value of impedance-corrected delivered energy of approximately 5 Joules/Ohm in determining the voltage to which the capacitor is to be charged in the repeated charging step.
Claim 7
Dependent Claim
27 words
The method of claim 3 which further includes repeating the charging and discharging steps if the patient's normal cardiac rhythm is not restored by the first discharge.
Claim 8
Dependent Claim
24 words
The method of claim 6 in which the repeated charging step includes charging the capacitor to a higher voltage than the voltage initially determined.
Claim 9
Dependent Claim
96 words
In a defibrillation method that includes the steps of detecting a patient's transthoracic impedance, calculating an electrical charge that corresponds to the detected impedance according to a predetermined relationship, providing the calculated electrical charge to a storage capacitor, and discharging the charged capacitor through the patient, an improvement wherein the predetermined relationship on which the capacitor charge is based is a desired value of delivered energy per unit of patient transthoracic impedance, said value being predetermined irrespective of particular characteristics of the patient and irrespective of the shape of the waveform produced in discharging the capacitor.
Claim 10
Dependent Claim
96 words
In a defibrillation method that includes the steps of detecting a patient's transthoracic impedance, calculating an electrical charge that corresponds to the detected impedance according to a predetermined relationship, providing the calculated electrical charge to a storage capacitor, and discharging the charged capacitor through the patient, an improvement wherein the predetermined relationship on which the capacitor charge is based is a desired value of delivered energy per unit of patient transthoracic impedance, said value being predetermined irrespective of particular characteristics of the patient and irrespective of the shape of the waveform produced in discharging the capacitor.
Claim 11
Dependent Claim
97 words
A defibrillator for providing a defibrillation pulse to a patient to restore normal cardiac rhythm, comprising: a capacitor; means for establishing a desired value of impedance-corrected delivered energy (E d Z); means for measuring a transthoracic impedance Z of the patient; means for determining the voltage to which the capacitor must be charged to provide the desired value of impedance-corrected delivered energy to a patient having the transthoracic impedance measured: means for providing charge to or from the capacitor until the voltage thereacross equals the calculated voltage; and means for discharging the charged capacitor through the patient.
Claim 12
Dependent Claim
97 words
A defibrillator for providing a defibrillation pulse to a patient to restore normal cardiac rhythm, comprising: a capacitor; means for establishing a desired value of impedance-corrected delivered energy (E d Z); means for measuring a transthoracic impedance Z of the patient; means for determining the voltage to which the capacitor must be charged to provide the desired value of impedance-corrected delivered energy to a patient having the transthoracic impedance measured: means for providing charge to or from the capacitor until the voltage thereacross equals the calculated voltage; and means for discharging the charged capacitor through the patient.
Claim 13
Independent Claim
131 words
A method of providing a defibrillation pulse to a patient to restore normal cardiac rhythm, the method comprising the steps: providing an energy storage device, the energy stored in said device being related by a formula to a physically measurable parameter; establishing a desired value of impedance-corrected delivery energy (E d /Z); measuring a transthoracic impedance Z of the patient; determining a first amount of energy, said first amount being the amount of energy to be delivered to the patient, said first amount being equal to the product of the impedance-corrected delivered energy and the patient's transthoracic impedance; providing to the energy storage device a second amount of energy calculated to provide to the patient said first amount of energy; and transferring energy stored in the storage device to the patient.
Claim 14
Independent Claim
131 words
A method of providing a defibrillation pulse to a patient to restore normal cardiac rhythm, the method comprising the steps: providing an energy storage device, the energy stored in said device being related by a formula to a physically measurable parameter; establishing a desired value of impedance-corrected delivery energy (E d /Z); measuring a transthoracic impedance Z of the patient; determining a first amount of energy, said first amount being the amount of energy to be delivered to the patient, said first amount being equal to the product of the impedance-corrected delivered energy and the patient's transthoracic impedance; providing to the energy storage device a second amount of energy calculated to provide to the patient said first amount of energy; and transferring energy stored in the storage device to the patient.
Claim 15
Dependent Claim
41 words
The method of claim 10 which further includes providing to the energy storage device more than the second amount of energy and diminishing the energy stored therein down to the second amount prior to transferring energy stored therein to the patient.
Claim 16
Dependent Claim
30 words
The method of claim 11 which further includes providing to the energy storage device more than the second amount of energy prior to measuring the transthoracic impedance of the patient.
Claim 17
Dependent Claim
32 words
The method of claim 1( in which the second amount of energy is greater than the first amount of energy to account for energy lost between the storage device and the patient.
Claim 18
Dependent Claim
62 words
The method of claim 10 in which the providing step includes: computing the value of the physically measurable parameter required to store in the energy storage device said second amount of energy; measuring the energy storage device to ascertain the value of said parameter; and providing energy to or from the energy storage device until the measured parameter equals the computed parameter.
Claim 19
Dependent Claim
88 words
A defibrillation method comprising the steps: detecting a patient's transthoracic impedance; providing a corresponding, target level of energy to an energy storage device, said target level being selected in response to the detected transthoracic impedance so as to provide a desired impedance-corrected delivered energy to the patient upon discharge of the device through the patient; said providing step including providing a second level of energy greater than said target level to the energy storage device; and removing energy from the storage device until the target level is reached.
Claim 20
Dependent Claim
88 words
A defibrillation method comprising the steps: detecting a patient's transthoracic impedance; providing a corresponding, target level of energy to an energy storage device, said target level being selected in response to the detected transthoracic impedance so as to provide a desired impedance-corrected delivered energy to the patient upon discharge of the device through the patient; said providing step including providing a second level of energy greater than said target level to the energy storage device; and removing energy from the storage device until the target level is reached.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-05-12 | 1995-11-11 | 1996-05-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-05-12 | 1999-11-11 | 2000-05-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-05-12 | 2003-11-11 | 2004-05-12 | $7700.00 | Window Closed / Lapsed |