US4328808A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Defibrillator with means for determining patient impedance and delivered energy
Assignee: Koninklijke Philips NV
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Filing: 1980-10-09
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Granted: 1982-05-11
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Expires: 2000-10-09
Abstract
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.
Inventors
- 👤 Francis M. Charbonnier
- 👤 Paul V. Long
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 14:01
CPC Classifications
A; A61; A61N; A61N1/00; A61N1/18; A61N1/32; A61N1/38; A61N1/39; A61N1/3925; A61N1/3931; A61N1/3937
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
142 words
Patient defibrillator apparatus comprising: means for storing high voltage patient defibrillation energy; patient electrode means coupled to said energy storage means for applying a defibrillation shock pulse to a patient; first means coupled to said energy storage means for determining the magnitude of stored defibrillation energy to be applied to said patient electrode means; second means coupled to said electrode means for sensing and holding the magnitude of the peak current applied to a patient during a defibrillation shock pulse; third means coupled to said first means and said second means for determining the actual transthoracic resistance of a patient being defibrillated, in response to the magnitudes of stored defibrillation energy and peak current; and fourth means coupled to said first means and said third means for determining the proportion of said stored defibrillation energy actually delivered to a patient during defibrillation.
Claim 2
Dependent Claim
142 words
Patient defibrillator apparatus comprising: means for storing high voltage patient defibrillation energy; patient electrode means coupled to said energy storage means for applying a defibrillation shock pulse to a patient; first means coupled to said energy storage means for determining the magnitude of stored defibrillation energy to be applied to said patient electrode means; second means coupled to said electrode means for sensing and holding the magnitude of the peak current applied to a patient during a defibrillation shock pulse; third means coupled to said first means and said second means for determining the actual transthoracic resistance of a patient being defibrillated, in response to the magnitudes of stored defibrillation energy and peak current; and fourth means coupled to said first means and said third means for determining the proportion of said stored defibrillation energy actually delivered to a patient during defibrillation.
Claim 3
Dependent Claim
44 words
The apparatus of claim 1 further including: means responsive to said third means for detecting when transthoracic resistance of a patient exceeds a predetermined threshold; and means responsive to said detecting means for indicating poor contact between said patient electrode means and the patient.
Claim 4
Dependent Claim
27 words
The apparatus of claim 1 further including recording means coupled to the output of said fourth means for visually indicating the energy actually delivered to a patient.
Claim 5
Dependent Claim
40 words
The apparatus of claim 1 wherein said second means for sensing the magnitude of peak current includes: a transformer in the current path established by said patient electrode means; and a peak detector coupled to the output of said transformer.
Claim 6
Dependent Claim
91 words
The apparatus of claim 4 wherein said third means for determining actual transthoracic resistance includes: first memory means, coupled to the output of said first means, for correlating values of stored energy to predetermined values of the reciprocal of the square root of stored energy; means for multiplying the output from said first memory means and the peak current output from said peak detector; and second memory means coupled to the output of said multiplying means for correlating output values from said multiplying means to predetermined values of patient transthoracic resistance.
Claim 7
Dependent Claim
48 words
The apparatus of claim 5 further including: means responsive to the output of said second memory means for detecting when values of transthoracic resistance exceed a predetermined threshold; and means responsive to said threshold detecting means for indicating poor contact between said patient electrode means and the patient.
Claim 8
Dependent Claim
91 words
The apparatus of claim 5 wherein said fourth means for determining energy actually delivered to a patient includes: third memory means coupled to the output of said multiplying means for correlating output values to predetermined values representing the ratio of transthoracic resistance to total circuit resistance established in the current path from said high voltage storing means through said patient electrode means to the patient; and means for multiplying the output from said third memory means and the output of said first means for determining the magnitude of stored defibrillation energy.
Claim 9
Dependent Claim
29 words
The apparatus of claim 7 further including recording means responsive to said last-named multiplying means for visually indicating the portion of stored defibrillation energy actually delivered to a patient.
Claim 10
Dependent Claim
124 words
Apparatus for applying a preset quantity of stored defibrillation energy through a pair of electrodes to a patient comprising: means for sensing the magnitude of peak current applied to a patient through said electrodes during a defibrillation shock pulse; means responsive to said sensing means for normalizing said peak current magnitude to the square root of said preset quantity of stored defibrillation energy; means responsive to said normalizing means for correlating the normalized peak current magnitude to a specific value of patient transthoracic resistance based on predetermined valuations; means responsive to said correlating means for detecting when transthoracic resistance of a patient exceeds a predetermined threshold; and means responsive to said threshold detecting means for indicating poor contact between said electrodes and the patient.
Claim 11
Dependent Claim
124 words
Apparatus for applying a preset quantity of stored defibrillation energy through a pair of electrodes to a patient comprising: means for sensing the magnitude of peak current applied to a patient through said electrodes during a defibrillation shock pulse; means responsive to said sensing means for normalizing said peak current magnitude to the square root of said preset quantity of stored defibrillation energy; means responsive to said normalizing means for correlating the normalized peak current magnitude to a specific value of patient transthoracic resistance based on predetermined valuations; means responsive to said correlating means for detecting when transthoracic resistance of a patient exceeds a predetermined threshold; and means responsive to said threshold detecting means for indicating poor contact between said electrodes and the patient.
Claim 12
Dependent Claim
30 words
The apparatus of claim 9 further including: means responsive to said normalizing means for determining the proportion of said preset stored defibrillation energy actually delivered to the patient during defibrillation.
Claim 13
Dependent Claim
33 words
The apparatus of claim 10 wherein said sensing means includes: a transformer in the current path established through said pair of electrodes; and a peak detector coupled to the output of said transformer.
Claim 14
Dependent Claim
62 words
The apparatus of claim 11 wherein said normalizing means includes: memory means responsive to values of said preset quantity of stored defibrillation energy for relating said value of stored energy to predetermined values of the reciprocal of the square root of stored energy; and means for multiplying the output from said memory means and the peak current output from said peak detector.
Claim 15
Dependent Claim
89 words
The apparatus of claim 12 wherein said means for determining the proportion of preset stored defibrillation energy actually delivered to a patient includes: memory means coupled to the output of said multiplying means for relating output values of normalized peak current to predetermined values representing the ratio of said transthoracic resistance to total circuit resistance established in the current path through said pair of electrodes to a patient; and means for multiplying the output from said last named memory means and the value of said preset stored defibrillation energy.
Claim 16
Dependent Claim
29 words
The apparatus of claim 13 further including recording means responsive to said last-named multiplying means for visually indicating the portion of stored defibrillation energy actually delivered to a patient.
References Cited (Backward Citations)
US3860009A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-05-10 | 1985-11-09 | 1986-05-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-05-10 | 1989-11-09 | 1990-05-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-05-10 | 1993-11-09 | 1994-05-11 | $7700.00 | Window Closed / Lapsed |