GB2166520A

GB2166520A - Suction regulator

Info

Publication number: GB2166520A
Application number: GB08520935A
Authority: GB
Inventors: Robert J Kurtz; Joseph M Licausi
Original assignee: Bioresearch Inc
Current assignee: Bioresearch Inc
Priority date: 1984-11-02
Filing date: 1985-08-21
Publication date: 1986-05-08
Also published as: AU574495B2; GB8520935D0; DE3537236C2; FR2572655A1; GB2166520B; JPS61109571A; JPH0622595B2; AU4614385A; DE3537236A1; CA1237618A

Abstract

A regulator is provided for controlling the degree of suction within a chamber (1). The regulator includes a means (6) for measuring the degree of negativity within the chamber and a passageway (3) leading from the measuring means to the suction source. When the measuring means detects a degree of negativity which is greater than a predetermined value in relation to the available suction the passageway (3) is opened to atmosphere at (7) and when the degree of negativity becomes equal to or less than the predetermined value the passageway (3) is closed so as to impose the full suction of the suction source upon the chamber. <IMAGE>

Description

SPECIFICATION Suction regulator The present invention relates to a device for regulating the suction level applied to a device connected with the body cavity of a patient.

In underwater drainage devices such as disclosed in US-A-3363626, there is provided means for regulating the suction level to reduce the suction from that available from the wall outlet in a hospital room to a predetermined value such as, for example, -20 to -30 centimeters of water. This means generally comprises a manometer which includes a U tube having a large arm and small arm with the small arm open to atmosphere. The U tube is filled to the level at which suction is desired and when the applied suction is greater than that desired, air will bubble through the U tube from the opening to atmosphere. This device will serve to maintain the suction level applied to the drainage device at the desired value provided there is no substantial air leak within the patient's pleural cavity.

It obviously is particularly desirable to maintain a predetermined suction level within the pleural cavity when an air leak exists in the pleural cavity so as to maintain the lung in a fully expanded condition. With prior air devices such as described hereinbefore even when the wall suction is as high as 50 centimeters of water and the suction control chamber is set to maintain a suction level of -20 centimeters of water, the actual suction level in the collection chamber may be as low as - 12 centimeters of water with a large air leak in the pleural cavity.

According to the present invention, there is provided a suction regulator for regulating the degree of suction applied to a chamber of a drainage device from a suction source, comprising means connected with the chamber for measuring the degree of negativity in the chamber, said feedback means for automatically adjusting the suction level imposed by the suction source in response to the degree of negativity in said chamber sensed by said measuring means.

The regulator of the present invention enables the full wall suction available to be applied to a drainage device in the event the suction level does not maintain the desired level by providing means for determining the actual degree of suction within the drainage device and immediately applying full wall suction in the event the suction level falls below the desired value. Thus, according to the present invention, there is provided a bellows having the inner chamber thereof connected with the collection chamber of a drainage device. The exterior of the bellows is connected to atmospheric pressure. A passageway is provided from wall suction, the inner end of this passageway being open and disposed immediately below the lower end of the bellows.

in one position of the bellows the lower end of the bellows will close the inner end of the passageway so as to exclude atmospheric air from entering the passageway to wall suction.

In a raised position of the bellows the lower end of the bellows will rise to permit atmospheric air to enter the passageway to wall suction. Thus, when the degree of negativity within the collction chamber is less than a predetermined value, for example, 20 centimeters of water, the bellows will close the passageway from wall suction to atmosphere so as to permit full wall suction to be applied to the collection chamber until the degree of negativity is greater than 20 centimeters of water. When the degree of negativity within the collection chamber is greater than the preset value, the bellows will rise, opening the passageway from wall suction to atmospheric pressure, thus reducing the negativitiy within the collection chamber.

Thus, the present invention provides means for regulating the suction level within a drainage device so as to maintain the desired suction level by immediately applying full wall suction to the collection chamber when the negativity drops below the desired level. The present invention thus provides a suction regulator for a drainage device which adjusts the applied suction in accordance with the actual suction level existing within the collection chamber. The present invention thus provides a pleural drainage device which will permit the application of full wall suction to the collection chamber and pleural cavity in the event of a large air leak within the pleural cavity.

The invention will now be described, by way of example, with reference to the drawings, in which: Figure 1 is a sectional elevation of a drainage device showing the suction control valve in a closed position; and Figure 2 is a sectional elevation of the drainage device of Fig. 1, showing the suction control valve in an open position.

Referring to Fig. 1 there is shown at 1 the collection chamber of a drainage device. The details of the drainage device are well known in the prior art and may be as shown in any one of US-A-4312351, US-A-4296748 or US A-4396386. A connection 2 is provided at the upper end of the drainage device for attachment of a thoracotomy tube. There is further provided a passageway 3 for connecting the collection chamber with a source of suction. The suction source may be the wall suction available in a hospital and means must be provided to reduce the higher suction levels which are normally available from such wall suction sources.

A suction regulator is provided which comprises means for measuring the suction level within the collection chamber together with a feedback passageway for adjusting the suction level of the applied wall suction in relation to the measured suction level existing in the collection chamber.

The measuring means comprises an extended portion 4 of the upper end of the collection chamber having an opening 5 therein for communication with the interior of a bellows 6. In US-A-4396386, there is disclosed a bellows for measuring the degree of negativity existing in the drainage device. The bel iows 6 is disposed within a chamber 7 which is provided with an opening 8 to atmosphere.

Thus, the exterior surface of the bellows is exposed to atmospheric pressure. As the degree of negativity within the bellows increases, the bellows will tend to contract, raising the lower end of the bellows.

At the lower end of chamber 7 there is provided the upstanding open end of a passageway 10. The opposite end of passageway 10 connects with passageway 3 which interconnects the collection chamber and wall suction. There is provided an 0 ring 11 on the open end of passageway 10 to form a seal between the lower end of bellows 6 and the upstanding open end of passageway 10 when the lower end of bellows 6 rests on the seal.

In Fig. 2 there is shown the position of the elements of the suction regulator when the negativity within the collection chamber is sufficiently high to cause the bellows to contract. It can be seen that in this condition of the device the passageway 10 is open to atmosphere from outlet 8 and through chamber 7. Thus, atmospheric air enters the passageway 3 and reduces the degree of suction applied to the collection chamber. As the suction level within the collection chamber is reduced, the bellows 6 will be lowered until the passageway 10 is closed to prevent atmospheric air from entering through inlet 8 and the degree of suction applied to the collection chamber is increased.

During normal operation of the device the bellows will be continually rising and falling or "hunting", closing the open end of passageway 10 when the degree of negativity within the collection chamber is less than the desired value and opening the passageway 10 when the full wall suction is applied to increase the degree of negativity within the chamber.

The presently disclosed suction regulator may be observed by the physician as an indicator of the condition of the patients pleural cavity. Large air leaks within the patient's pleural cavity would tend to lengthen the period during which the passageway 10 is closed and shorten the period during which the passageway 10 is opened.

Obviously many modifications and variations of the present invention are possible in light of the foregoing disclosure.

Claims

1. A suction regulator for regulating the degree of suction applied to a chamber of a drainage device from a suction source, comprising means connected with the chamber for measuring the degree of negativity in the chamber, and feedback means for automatically adjusting the suction level imposed by the suction source in response to the degree of negativity in said chamber sensed by said measuring means.

2. A suction regulator according to claim 1, wherein said feedback means includes a passageway from said suction source to said measuring means for admitting supplemental air to said suction source.

3. A suction regulator according to claim 1 or 2, wherein said measuring means includes a bellows, the interior of the bellows being connected to said chamber and the exterior of said bellows being open to atmosphere.

4. A suction regulator according to claim 3, wherein said feedback means includes a passageway extending from the suction source to an open end adjacent the lower surface of said bellows, the lower surface of said bellows closing said open end when the degree of negativity in said chamber is less than a predetermined level and the open end of said passageway being open to ambient atmosphere when the degree of negativity in said chamber is greater than the predetermined level.

5. A suction regulator according to claim 4, wherein a compartment surrounds said bellows, there being an inlet in said compartment, said air inlet being open to atmosphere and connecting said feedback means with atmosphere when the negativity within the collection chamber is less than the predetermined level.

6. A suction regulator according to claim 1, substantially as hereinbefore described with reference to, and as claimed in, the drawings.