Patent GB794580A successfully refreshed from Google Patents.
US4269195A
Expired / Lapsed
US
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Apparatus for measuring a pulmonary function
Assignee: Toshiba Corp
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Filing: 1979-05-23
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Granted: 1981-05-26
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Expires: 1999-05-23
Abstract
Abstract A plurality of impedance pneumographs for measuring impedances at the locations of a human thorax are provided together with a pneumotachograph for measuring an amount of respiration. An impedance value measured at the inhalation starting point is subtracted from an impedance value measured at other time points to obtain an impedance variation. The impedance variations corresponding to the locations of the thorax are added to obtain a sum of the impedance variations. A ratio of the impedance at each location of the thorax to the sum of the impedance variations is calculated and an amount of ventilation at each location of the thorax is found by the impedance ratio and respiration amount.
Inventors
- 👤 Ayao Itoh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 08:17
CPC Classifications
A; A61; A61B; A61B5/00; A61B5/08; A61B5/085; A61B5/086
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
171 words
An apparatus for measuring a pulmonary function, comprising: a plurality of paired electrodes adapted for attachment to locations on a human thorax corresponding to the lungs of a human being, each of said paired electrodes including a current supply electrode element and voltage detection electrode element; means for measuring impedances at the respective locations of the lungs, said means including a constant current source for supplying a constant current to the current supply electrode of each electrode pair; detecting means coupled to said voltage detection electrode of each of said paired electrodes for detecting impedance variations indicative of respiratory movement from the impedances at the respective locations of the lungs; sum calculating means for calculating a sum of the impedance variations detected by said detecting means; ratio calculating means for calculating a ratio of each of the impedance variations to the sum of the impedance variations which is obtained by said sum calculating means; and means for determining the pulmonary function using the ratio data obtained by said ratio calculating means.
Claim 2
Independent Claim
171 words
An apparatus for measuring a pulmonary function, comprising: a plurality of paired electrodes adapted for attachment to locations on a human thorax corresponding to the lungs of a human being, each of said paired electrodes including a current supply electrode element and voltage detection electrode element; means for measuring impedances at the respective locations of the lungs, said means including a constant current source for supplying a constant current to the current supply electrode of each electrode pair; detecting means coupled to said voltage detection electrode of each of said paired electrodes for detecting impedance variations indicative of respiratory movement from the impedances at the respective locations of the lungs; sum calculating means for calculating a sum of the impedance variations detected by said detecting means; ratio calculating means for calculating a ratio of each of the impedance variations to the sum of the impedance variations which is obtained by said sum calculating means; and means for determining the pulmonary function using the ratio data obtained by said ratio calculating means.
Claim 3
Independent Claim
207 words
An apparatus for measuring a pulmonary function, comprising: a plurality of paired electrodes adapted for attachment to locations on a human thorax, corresponding to a plurality of fields of the lungs, and with each of said paired electrodes including a current supply electrode element and voltage detection electrode element; impedance measuring means connected to the paired electrodes for measuring impedances at the respective locations of the lung fields, said impedance measuring means including a constant current source for supplying a constant current to the current supply electrode of each electrode pair; detecting means coupled to said voltage detection electrode of each of said paired electrodes for detecting impedance variations indicative of respiratory movement from impedance data representing those impedances at the respective lung fields which are measured by the impedance measuring means; sum calculating means for calculating a sum of impedance variations detected by said detecting means; respiration measuring means for measuring a volume of respiration from the lungs; and ventilation volume calculating means for calculating a volume of ventilation at each of the fields of the lungs from the volume of respiration measured by said respiration measuring means and sum of the impedance variations obtained by said sum calculating means and each of the impedance variations.
Claim 4
Independent Claim
207 words
An apparatus for measuring a pulmonary function, comprising: a plurality of paired electrodes adapted for attachment to locations on a human thorax, corresponding to a plurality of fields of the lungs, and with each of said paired electrodes including a current supply electrode element and voltage detection electrode element; impedance measuring means connected to the paired electrodes for measuring impedances at the respective locations of the lung fields, said impedance measuring means including a constant current source for supplying a constant current to the current supply electrode of each electrode pair; detecting means coupled to said voltage detection electrode of each of said paired electrodes for detecting impedance variations indicative of respiratory movement from impedance data representing those impedances at the respective lung fields which are measured by the impedance measuring means; sum calculating means for calculating a sum of impedance variations detected by said detecting means; respiration measuring means for measuring a volume of respiration from the lungs; and ventilation volume calculating means for calculating a volume of ventilation at each of the fields of the lungs from the volume of respiration measured by said respiration measuring means and sum of the impedance variations obtained by said sum calculating means and each of the impedance variations.
Claim 5
Dependent Claim
26 words
An apparatus according to claim 2 in which said impedance measuring means comprises a plurality of impedance pneumographs each connected to the corresponding pairs of electrodes.
Claim 6
Dependent Claim
68 words
An apparatus according to claim 2 or 3 in which said detecting means comprises signal producing means for producing first and second signals in response to inhalation and exhalation starting points respectively of respiration, and a circuit for subtracting an impedance value at the exhalation starting point from the measured impedance value of said impedance measuring means in response to said first signal of said signal producing means.
Claim 7
Dependent Claim
24 words
An apparatus according to claim 2 or 3, further including means for displaying an amount of ventilation obtained by said ventilation amount calculating means.
Claim 8
Dependent Claim
43 words
An apparatus according to claim 2 or 3 in which said ventilation amount calculating means comprises circuit means for dividing a product of the value of each of the respective impedance variations and amount of respiration by a sum of the impedance variations.
Claim 9
Dependent Claim
18 words
An apparatus according to claim 2 in which said respiration amount measuring means is constructed of a pneumotachograph.
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) | 1984-05-25 | 1984-11-24 | 1985-05-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-05-25 | 1988-11-24 | 1989-05-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-05-25 | 1992-11-24 | 1993-05-26 | $7700.00 | Window Closed / Lapsed |