Patent US5143078A successfully refreshed from Google Patents.
US5143078A
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US
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Respiration rate monitor
Assignee: Colin Medical Technology Corp
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Filing: 1989-09-29
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Granted: 1992-09-01
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Expires: 2009-09-29
Abstract
Abstract A monitoring system for providing an accurate indication of a patient's respiration rate. The system is effective in eliminating or significantly reducing the effects of heart sounds and ambient noise. The system comprises means for obtaining a first signal waveform containing components corresponding to the patient's breath sounds, as well as components corresponding to heart sounds and ambient noise. The signal is passed through a digital bandpass filter having a passband selected to remove heart sounds and ambient noise to produce a second waveform. From the second waveform the total energy is computed of a portion of the signal within a moving window of predetermined length. The resulting energy envelope signal is smoothed and then high-pass filtered by removing the average DC value of the signal over a predetermined preceding time interval. Respiration is detected by identifying significant, positive-going zero crossings of the resulting signal through a band about zero. The zero-band threshold used to obtain this waveform can be controlled by the operator or pre-set for a particular sensitivity.
Inventors
- 👤 Bruce C. Mather
- 👤 Dean C. Winter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 14:50
CPC Classifications
A; A61; A61B; A61B5/00; A61B5/08; A61B5/0816; A61B7/00; A61B7/003
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
139 words
A system for monitoring the respiration rate of a patient, comprising: means for detecting acoustical energy generated by said patient and for producing a first output signal in response thereto, said output signal comprising a component corresponding to breath sounds, a component corresponding to heart sounds and a component corresponding to ambient noise; means for filtering said first output signal to remove said components corresponding to said heart sounds and ambient noise and for producing a second output signal corresponding only to said breath sounds; means for producing an AC coupled energy signal corresponding to the breath sound energy level of said second output signal; and means for identifying significant positive-going zero crossings in said AC coupled energy signal within a band of predetermined width and for correlating said significant zero crossings with the respiration rate of said patient.
Claim 2
Independent Claim
139 words
A system for monitoring the respiration rate of a patient, comprising: means for detecting acoustical energy generated by said patient and for producing a first output signal in response thereto, said output signal comprising a component corresponding to breath sounds, a component corresponding to heart sounds and a component corresponding to ambient noise; means for filtering said first output signal to remove said components corresponding to said heart sounds and ambient noise and for producing a second output signal corresponding only to said breath sounds; means for producing an AC coupled energy signal corresponding to the breath sound energy level of said second output signal; and means for identifying significant positive-going zero crossings in said AC coupled energy signal within a band of predetermined width and for correlating said significant zero crossings with the respiration rate of said patient.
Claim 3
Dependent Claim
28 words
A system in accordance with claim 1, wherein said means for filtering said first output signal comprises a bandpass filter having a passband of 300 to 600 Hz.
Claim 4
Dependent Claim
29 words
A system in accordance with claim 2, wherein said means for producing said AC coupled energy signal comprises means for calculating the root-mean-square energy of said second output signal.
Claim 5
Independent Claim
130 words
A method for determining respiration rate of a patient, comprising the steps of: detecting acoustical energy generated by said patient and producing a first output signal in response thereto, said output signal comprising a component corresponding to breath sounds, a component corresponding to heart sounds and a component corresponding to ambient noise; filtering said first output signal to remove said components corresponding to said heart sounds and ambient noise and producing a second output signal corresponding only to said breath sounds; producing an AC coupled energy signal corresponding to the breath sound energy level of said second output signal; and identifying significant positive-going zero crossings in said AC coupled energy signal within a band of predetermined width and correlating said significant zero crossings with the respiration rate of said patient.
Claim 6
Independent Claim
130 words
A method for determining respiration rate of a patient, comprising the steps of: detecting acoustical energy generated by said patient and producing a first output signal in response thereto, said output signal comprising a component corresponding to breath sounds, a component corresponding to heart sounds and a component corresponding to ambient noise; filtering said first output signal to remove said components corresponding to said heart sounds and ambient noise and producing a second output signal corresponding only to said breath sounds; producing an AC coupled energy signal corresponding to the breath sound energy level of said second output signal; and identifying significant positive-going zero crossings in said AC coupled energy signal within a band of predetermined width and correlating said significant zero crossings with the respiration rate of said patient.
Claim 7
Dependent Claim
27 words
The method according to claim 4, wherein said means for filtering said first output signal comprises a bandpass filter having a passband of 300 to 600 Hz.
Claim 8
Dependent Claim
28 words
The method according to claim 5, wherein said means for producing said AC coupled energy signal comprises means for calculating the root-mean-square energy of said second output signal.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-09-01 | 1996-03-02 | 1996-09-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-09-01 | 2000-03-02 | 2000-09-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-09-01 | 2004-03-02 | 2004-09-01 | $7700.00 | Window Closed / Lapsed |