Spirometers

Claim 2

A self-contained hand-portable spirometer, comprising a hand-portable container having an inlet for receiving air exhaled by a patient, an expansible chamber in the container and having an air inlet connected to the said inlet of the container for receiving the air exhaled by the patient, the expansible chamber being defined by wall means of substantially air-tight solid-phase material, indicating means attached to the container, control means releasably rendering the indicating means responsive to the chamber expansion for indicating the volume of the said air received, timing means attached to the container, means responsive to the initial receipt of the exhaled air by the chamber for initiating the timing means to produce a timing signal for indicating a measuring instant at a predetermined time after the initial receipt of the exhaled air, and means responsive to the said timing signal for actuating the control means to render the indicating means unresponsive to the expansion of the chamber and to maintain the indication of the indicating means at the said predetermined instant.

Claim 3

A spirometer according to claim 1, in which the said chamber is mounted in the container to expand in a horizontal direction when the container is in its normal attitude, the indicating means comprises an indicator member, a scale member mounted to be in register with the indicator member, and means fixedly coupling one of the said members to the container; and the said control means comprises releasable coupling means releasably coupling the other of the said members to the chamber to move therewith relative to the said one of the members as the chamber expands, and means responsive to the said timing signal to actuate the said releasable coupling means to release the other of the said members from the chamber at the predetermined instant.

Claim 4

A spirometer according to claim 2, in which the said one member is the scale member, and including a further indicator member and means fixedly coupling the further indicator member to the chamber for causing uninterruptable relative movement between this indicator member and the scale member as the chamber expands.

Claim 5

A spirometer according to claim 1, in which the indicating means comprises an indicator member, a scale member mounted to be in register with the indicator member, means fixedly coupling one of the said members to the chamber to move therewith as the chamber expands, and means providing a force acting between the two said members and tending to cause them to move together as the chamber expands, and the said control means comprises releasable locking means releasably locking the other of the said members to the container against the action of the said force, and means responsive to the said timing signal to release the locking means whereby to allow the two said members to thereafter move together under the action of the said force.

Claim 6

A spirometer according to claim 4, in which the said one member is the scale member and including a further indicator member in register with the scale member and means fixedly coupling the further indicator member to the container for causing uninterruptable movement of this indicator member and the scale member as the chamber expands.

Claim 7

A spirometer according to claim 1, including air flow responsive means mounted in the said inlet to the container and operative to produce a count signal in response to each incipient reversal of air flow in the said inlet, and counting means for counting the said count signals to indicate the number of separate exhalations of air into the chamber.

Claim 8

A spirometer according to claim 1, in which the said expansible chamber is defined by an expansible bellows.

Claim 9

A self-contained hand-portable spirometer, comprising a hollow hand-held portable container having an air inlet for recEiving air exhaled by a patient, an expansible substantially air-tight chamber supported in the container and having an air inlet coupled to the said air inlet of the container for receiving air exhaled by the patient, the air-tight chamber being defined by wall means made of solid-phase substantially air-tight material at least part of which is flexible and the remainder of which is non-flexible, first and second indicating means mounted to the container for indicating the amount of expansion of the chamber, means fixedly coupling the first indicating means to the chamber to indicate continuously the amount of expansion thereof, timing means attached to the container, means on the container and responsive to initial receipt of air by the chamber to actuate the timing means to produce a control signal at the end of a fixed duration initial period of a single exhalation, and control means responsive to the said control signal and mounted in the container to releasably render the second indicating means responsive to the chamber expansion only until the said control signal occurs, whereby the second indicating means indicates only the amount of expansion of the chamber during the said inital period.

Claim 10

A self-contained hand-portable spirometer, comprising a hollow hand-held portable container having an air inlet for recEiving air exhaled by a patient, an expansible substantially air-tight chamber supported in the container and having an air inlet coupled to the said air inlet of the container for receiving air exhaled by the patient, the air-tight chamber being defined by wall means made of solid-phase substantially air-tight material at least part of which is flexible and the remainder of which is non-flexible, first and second indicating means mounted to the container for indicating the amount of expansion of the chamber, means fixedly coupling the first indicating means to the chamber to indicate continuously the amount of expansion thereof, timing means attached to the container, means on the container and responsive to initial receipt of air by the chamber to actuate the timing means to produce a control signal at the end of a fixed duration initial period of a single exhalation, and control means responsive to the said control signal and mounted in the container to releasably render the second indicating means responsive to the chamber expansion only until the said control signal occurs, whereby the second indicating means indicates only the amount of expansion of the chamber during the said inital period.

Claim 11

A spirometer according to claim 8, including a scale member on the container, and in which the first indicating means comprises a first indicator member in register with the scale member, one of the said members being fixed to the chamber to move therewith and the other said member being fixed to the container so that the two said members undergo continuous relative movement in register with each other as the chamber expands, and the second indicating means comprises a second indicator member in register with the scale member and releasably coupled by the said control means to the first indicator member so that the second indicator member and the said scale member undergo relative movement in register with each other only for the length of the said initial period.

Claim 12

A spirometer according to claim 9, in which the said scale member is fixed to the chamber for continuous movement therewith as the chamber expands, the first indicator member is fixedly attached to the container, and the second indicator member is frictionally coupled to the scale member; and the said control means comprises clamping means for clamping the second indicator member to the container during the said initial period so that the scale member moves relative to the second indicator member until the end of the initial period and thereafter moves with the said scale member.

Claim 13

A spirometer according to claim 9, in which: the said chamber is mounted in the container to expand in a horizontal direction when the container is in its normal attitude, the said scale member is fixedly attached to the container, the first indicator member is fixedly coupled to chamber to move along the scale member as the chamber expands, and the second indicator member is mounted for movement along the scale member; and the control means comprises clamping means for releasably clamping the second indicator member to the chamber to move therewith for the duration of the said initial period, and locking means operative in response to the said control signal to lock the second indicator member relative to the base against further movement along the scale member.

Claim 14

Apparatus according to claim 8, in which the means responsive to the initial entry of the exhaled air comprises a microswitch mounted on the said container to be actuated in response to the initial expansion of the chamber.

Claim 15

Apparatus according to claim 8, in which the means responsive to the initial entry of the exhaled air comprises means in one said inlet to respond to the air flow therethrough.

Claim 16

A spirometer according to claim 8, in which the container air inlet includes a mouthpiece for the patient, a tube coupling the mouthpiece to the expansible chamber, A first non-return valve in the said tube, and a second non-return valve coupling the said tube to atmosphere, the first non-return valve being arranged to allow entry of exhaled air into the chamber but blocking the return of such air, and the second non-return valve blocking the exit of the exhaled air to atmosphere but allowing the patient to inhale air from the atmosphere through the said tube and mouthpiece.

Claim 17

A spirometer, comprising a base, an expansible air-tight chamber supported on the base and having inlet means for receiving air exhaled by a patient, a scale mean fixed to the chamber for continuous movement therewith as the chamber expands, a first indicator means in register with the scale means and fixedly attached to the base whereby it and the scale means continuously indicate the amount of expansion of the chamber, means mounted on the base and responsive to initial receipt of the exhaled air to produce a control signal at the end of the fixed duration initial period of a single exhalation, a second indicator means frictionally coupled to the scale means, an electrically energisable electromagnet means mounted on the base for magnetically locking the second indicator means to the base during the said initial period so that the scale means moves relative to the second indicator means to indicate the amount of expansion of the chamber during the said initial period, and means mounted on the base and responsive to the said control signal for de-energising the electromagnet at the end of the initial period so that the second indicator means thereafter moves with the said scale.

Claim 18

A spirometer, comprising a base, an expansible air-tight chamber supported on the base and having inlet means for receiving air exhaled by a patient, a scale mean fixed to the chamber for continuous movement therewith as the chamber expands, a first indicator means in register with the scale means and fixedly attached to the base whereby it and the scale means continuously indicate the amount of expansion of the chamber, means mounted on the base and responsive to initial receipt of the exhaled air to produce a control signal at the end of the fixed duration initial period of a single exhalation, a second indicator means frictionally coupled to the scale means, an electrically energisable electromagnet means mounted on the base for magnetically locking the second indicator means to the base during the said initial period so that the scale means moves relative to the second indicator means to indicate the amount of expansion of the chamber during the said initial period, and means mounted on the base and responsive to the said control signal for de-energising the electromagnet at the end of the initial period so that the second indicator means thereafter moves with the said scale.

Claim 19

A spirometer, comprising a base, an expansible air-tight chamber supported on the base and having inlet means for receiving air exhaled by a patient, a scale means fixedly attached to the base, a first indicator means fixedly coupled to the chamber and mounted in register with the scale means to move along the scale means as the chamber expands so as to indicate continuously the amount of expansion of the chamber, means mounted on the base and responsive to the initial receipt of the exhaled air to produce a control signal at the end of a fixed duration initial period of a single exhalation, a second indicator means mounted on the base for movement in register with the said scale means, a magnet means mounted for magnetically clamping the second indicator means to the chamber so that the chamber draws the second indicator means along its path of movement to indicate the expansion of the chamber during the said initial period, and locking means mounted on the base and operative in response to the said control signal to lock the second indicator means to the base against further movement along the scale.

Claim 20

A spirometer, comprising a base, an expansible air-tight chamber supported on the base and having inlet means for receiving air exhaled by a patient, a scale means fixedly attached to the base, a first indicator means fixedly coupled to the chamber and mounted in register with the scale means to move along the scale means as the chamber expands so as to indicate continuously the amount of expansion of the chamber, means mounted on the base and responsive to the initial receipt of the exhaled air to produce a control signal at the end of a fixed duration initial period of a single exhalation, a second indicator means mounted on the base for movement in register with the said scale means, a magnet means mounted for magnetically clamping the second indicator means to the chamber so that the chamber draws the second indicator means along its path of movement to indicate the expansion of the chamber during the said initial period, and locking means mounted on the base and operative in response to the said control signal to lock the second indicator means to the base against further movement along the scale.

Claim 21

A spirometer according to claim 16, including endless cord means having one of its runs extending alongside the scale means and fixed to the second indicator means, and in which the locking means comprises braking means for braking the cord against further movement.