DEVICE AND METHOD FOR MAKING A CONNECTION BETWEEN A VOLUME AND THE SURROUNDINGS

Abstract: A device for making a connection between a volume and the surroundings, comprising an air duct (8) for pressure compensation between the volume and the surroundings. The device is characterised by a container connected to the air duct (8) and having a centrally arranged outlet (3) which opens into the surroundings. As a result, fluid (6) which is transferred from the volume to the container through the air duct (8) is collected in a leakage-free manner by the container, independently of its orientation, as long as the surface level of the fluid (6) is below the level of the outlet (3) while simultaneously allowing said pressure compensation.

Description: DEVICE AND METHOD FOR MAKING A CONNECTION BETWEEN A VOLUME AND THE SURROUNDINGS Field of the Invention The present invention relates to a device and a method for making a connection between a volume and the surroundings. More specifically, the invention con- cerns such a device comprising an air duct for pressure compensation between the volume and the surroundings, and such a method comprising the step of connecting, with the aid of a first duct means, the volume with the surroundings, thereby achieving a pressure prevailing in the surroundings also in the volume. Background Art There are a great number of situations, in which the pressure in a volume should be adjusted to the pressure prevailing in the surroundings. In some situations, it may be desirable to collect liquid leaving the volume in connection with the pressure compensation, and in other situations, it may be desirable to see to it that liquid does not at all leave the volume in connection with the pressure compensation. The device and the method described by way of introduction can be used when it is desirable to collect fluid which possibly leaves the volume in connection with the pressure compensation. One end of a duct, such as a tube, is connected to the volume and the other end is connected to an inlet of a container. Owing to the pressure compensation effected by means of the tube, the same pressure will prevail in the container and in the volume, and since the pressure in the container corresponds to the pressure of the surroundings, it is this pressure that will prevail in the volume. During the pressure compensation, a flow of liquid may arise in the tube and will be collected by the container. One field of application for a device of the above type is in medical treatment where it may be used as a dual-lumen gastric probe. A gastric probe is a thin plastic tube, which through a patient's nose or mouth is passed into the patient's stomach. The purpose of the gastric probe can be to assist in the nutrient supply if the patient is not able to eat in a normal way, to drain the gastrointestinal duct in case of a reduced function thereof, or to act as an internal supporting bandage for a damaged gullet. A problem when using a gastric probe is that a fluid column often arises in the tube and may cause, by acting as a pipette, pressure and suction in either direction. This action as a pipette is in most cases undesirable, and therefore a dual-lumen gastric probe is frequently used, i.e. a tube having two ducts, one being narrower than the other and acting as an air duct and pressure equaliser. A small flow of gastric juice may arise in the air duct, and this fluid can be collected in a container of the above-mentioned type. The container may also be used together with a single- lumen or single-duct probe where small fluid volumes are involved, such as in neonatal intensive care. Here also draining of a urinary bladder by means of a single-lumen catheter may be involved. In its simplest form, such a container is an open vessel, of which both the inlet and the outlet are formed of the opening of the vessel. For instance, in the case of the dual-lumen gastric probe, one end of the air duct of the probe is quite loosely arranged in the ves- sel. However, the use of an open vessel is disadvantageous since someone may happen to knock against the vessel or remove the probe from the vessel, which causes leakage and makes the patient as well as his bed dirty. Leaking fluid on the floor also causes a risk that people staying in the vicinity of the patient will slide. As a result, the nursing staff sometimes block the air duct and, thus, put it out of operation to avoid the unplea- sant work with the washing of the patient and the exchange of bedclothes. The collecting of fluid in a vessel closed towards the surroundings would certainly eliminate the risk of leakage but prevents pressure compensation and, consequently, the intended function of the air duct. Moreover, a vessel of the above-mentioned type requires relatively much space, which is disadvantageous since the vessel is normally arranged in connection with a surface accommodating a great deal of other things in the patient's head region. The method described by way of introduction can also be used when it is desirable to adjust the pressure in a volume to the pressure prevailing in the surroundings and simultaneously that no fluid leaves the volume. The fluid is then arranged in a container with an outlet formed in the top and opening into the surroundings. In some cases, however, it is desirable to be able to turn or rotate the container, and on these occasions it is necessary for the level of the outlet not to be lower than the surface level of the fluid to prevent the fluid from leaving the container. Of course, this results in disadvantageous limitations as to the orientation of the container . A first object of the present invention is to pro- vide a device which makes a connection between the surroundings and a volume and which, independently of its orientation, reliably collects liquid leaving the volume, while simultaneously allowing pressure compensation between the volume and the surroundings . A second object of the present invention is to provide a method for pressure compensation between a volume and the surroundings, said method allowing said pressure compensation without any risk of fluid leaking from the volume to the surroundings. Summary of the Invention The first object is achieved by a device having the features stated in claim 1. Preferred embodiments of the device appear from subclaims 2-10. The second object is achieved by a method having the features stated in claim 11. Preferred features of the method appear from subclaims 12 and 13. According to the invention, more specifically a device is provided for making a connection between a volume and the surroundings, comprising an air duct for pressure compensation between the volume and the surroundings, said device being characterised by a container which is connected to the air duct and which has a centrally arranged outlet which opens into the surroundings and through which fluid, which through the air duct is transferred from the volume to the container, is collected in a leakage-free manner by the container, independently of its orientation, as long as the surface level of the fluid is below the level of the outlet while simultaneously allowing said pressure compensation. As a result, the pressure in a volume can be adjust ¬ ed to the pressure of the surroundings without any risk of spillage of fluid, which through the air duct is discharged from the volume . According to a first preferred embodiment of the inventive device, one side of the container is designed so that an area of the side is arranged centrally in the container, in which area the outlet is formed. Preferably this side consists of the container bottom. The bottom preferably has the shape of a funnel extending into the container. The outlet is formed in the narrow end of the funnel, said narrow end being arranged centrally in the container . According to a second preferred embodiment of the invention, a duct extends into the container, one end of the duct opening centrally in the container and forming said outlet, and the other end of the duct opening outside the container. The outlet preferably comprises an externally opening end which is designed in such a manner that it can hold a syringe for, for example, rinsing with water or air through the outlet. Preferably the container is essentially oval in cross-section. The oval cross-sectional shape is advantageous, for example, when the container is used toge- ther with a dual-lumen gastric probe, i.e. a double-duct gastric probe since a patient can sometimes get the container under himself, in which case the flat shape of the container makes it less inconvenient to lie on. Moreover the flat shape ensures that the lying container is less disposed to roll away. Preferably the container is made of a transparent material. This makes it possible for a person to see when the fluid collected by the container gets near half the container volume and it is time to replace or empty the container. Preferably the container is made of a flexible material. This makes it possible to compress the container and, thus, reduce its volume. According to one more preferred embodiment of the inventive device, said air duct constitutes the air duct of a dual-lumen gastric probe for making a connec ¬ tion between the surroundings and a patient's stomach, said container being intended for leakage-free collection of gastric juice while simultaneously allowing pressure compensation between the stomach and the surroundings. As a result, use of a dual-lumen gastric probe thus is possible without any risk of spillage of gastric juice which through the air duct is transferred from a patient's stomach to the container. According to the invention, a method is also provided for making a connection between a volume and the sur ¬ roundings, comprising the step of connecting, with the aid of a first duct means, the volume with the surroundings such that a pressure prevailing in the surroundings is also obtained in the volume, said method being characterised by the step of forming a portion of the first duct means, said portion comprising at least part of the first duct means, as a centrally arranged outlet of a container, said outlet opening into the surroundings, thereby ensuring said pressure compensation independently of the orientation of the container, without any risk of leakage of a fluid in the container as long as the surface level of the fluid is below the level of the outlet. A first preferred embodiment of the inventive method comprises the step of connecting, with the aid of a second duct means, the volume with an inlet of the con- tainer, which together with the second duct means forms said first duct means, whereby fluid leaving the volume through the second duct means is collected by the container in a leakage-free manner independently of its orientation as long as the surface level of the fluid is below the level of the outlet while simultaneously allow ¬ ing said pressure compensation. As a result, for instance a first end of the air duct of a dual-lumen gastric probe can be arranged in the stomach of a patient while a second end of the air duct is connected to the inlet of the container. Thus, pressure compensation between the stomach and the surroundings is ensured, independently of the orientation of the container, while simultaneous ¬ ly allowing leakage-free collection of any gastric juice leaving the air duct. A second embodiment of the inventive method comprises the step of letting the volume be formed of said container, which thus in a leakage-free manner keeps fluid independently of its orientation as long as the surface level of the fluid is below the level .of the out- let while simultaneously allowing said pressure compensation through said first duct means, which is thus formed of the outlet of the container. As a result, a fluid in the container can undergo a gas-generating process, such as fermentation, during simultaneous turning of the container. By seeing to it that the surface level of the fluid is always below the level of the outlet, it is thus possible to ensure that no leakage occurs while simultaneously allowing adjustment of the pressure prevailing in the volume to the pressure of the surroundings. Preferred embodiments of the invention will now be described for the purpose of exemplification, with refe- rence to the accompanying drawings. Brief Description of the Drawings Fig. 1 is a side view of a preferred embodiment of the container according to the invention, which is arranged in a first position. Fig. 2 shows the container in Fig. 1 in a second position. Fig. 3 shows the container in Fig. 1 in a third position. Fig. 4 is a top plan view of the embodiment in Fig. 1. Fig. 5 is a view in which the container in Fig. 1 is arranged in a new first position and is connected to an air duct of a dual-lumen gastric probe. Fig. 6 shows the container in Fig. 5 in a second position. Fig. 7 shows the container in Fig. 5 in a third position. Fig. 8 illustrates a second embodiment of the inven- tive container. Description of Embodiments Fig. 1, to which reference is made, shows a preferred embodiment of the inventive container. The container comprises a body 1, an inlet 2 and an outlet 3. The inlet 2 is formed in the narrow upper end of a funnel-shaped portion 4 which extends outwards from the upper side of the body 1. The outlet 3 is formed in the narrow upper end of a similar funnel-shaped portion 5 which extends into the body 1 from the underside thereof. It goes without saying that the portion 5 need not be in the shape of a funnel but can have any suitable design whatever. The funnel-shaped lower portion 5 extends so far into the body 1 that its upper end, in which the outlet 3 is formed, is arranged centrally in the container. When using the container, fluid 6 is supplied to the same, the fluid 6 being collected by the container as long as the surface level of the fluid is below the level of the outlet. Should the supply of fluid then continue, the fluid 6 will leave the container through the outlet 3. Preferably the container is made of a transparent material such as glass or transparent plastic. This is particularly advantageous when the container is connected to an air duct for pressure compensation between a volume and the surroundings while simultaneously collecting any fluid in the container, which fluid leaves the volume through the duct. This makes it possible for a person to observe that the surface level of the fluid gets near the level of the outlet and it is time to replace or empty the container. It is also preferable to make the container of a flexible material to allow compression of the container. The advantage of such compression will be described below. According to an embodiment of the invention (not shown) , annular grooves are formed on the upper portion 4 around the inlet 2. This results in an improved attachment for a duct, such as a tube, which is connected to the inlet 2 of the container. In Figs 2 and 3, the container is oriented in a second and a third position respectively. The fluid- keeping function of the container is maintained in these positions while the outlet 3 ensures that the pressure in the container corresponds to that of the surroundings. The container shown in Figs 1-3 can be used as a vessel for chemical processes generating gas. A fluid 6 which is to undergo such a process, is supplied to the container through the inlet 2, which is then closed. In this connection it is essential to see to it that the surface level of the fluid 6 in all orientations of the container is below the level of the outlet 3. The con- tainer can then be turned or rotated as desired, without the fluid 6 in the container leaking therefrom while simultaneously allowing pressure compensation between the surroundings and the container. An example of such a chemical process is fermentation. As appears from Fig. 4, to which reference is made, the container is oval in cross-section. The oval cross- sectional shape reduces the movability of the container, i.e. its tendency to roll away when lying. The oval cross-sectional shape of the container is particularly advantageous when the container is used in medical treatment in a device comprising a probe, such as a dual-lumen gastric probe. In this case, the container is normally used in a patient's bed, the flat shape of the container reducing the discomfort to the patient if he should hap- pen to place himself on the container. In Figs 5-7, to which reference is made, the container is connected to an air duct 8 of a dual-lumen gastric probe. The dual-lumen gastric probe also comprises a main duct 7. The purpose of the air duct 8 is to effect pressure compensation between, for instance, a patient's stomach (not shown) and the surroundings. The inlet 2 of the container is connected to one end 9 of the air duct 8, to collect the small amount of e.g. gastric juice that may arise in the air duct 8. The container ensures that the pressure compensation function of the air duct 8 is maintained during the collection of fluid. The arrows illustrated in Fig. 5 indicate how gas and fluid from the stomach (not shown) through the air duct 8 is supplied to the container through its inlet 2, and then how the gas is discharged from the container through its outlet 3. However the container serves as a two-way gas valve, which means that gas can also be supplied to the stomach (not shown) through the air duct 8 and in this way equalise a negative pressure prevailing in the stomach. A negative pressure in the stomach may arise when suction is applied by the main duct 7 or when caused by the peristaltic of the stomach. According to the embodiment shown in Fig. 5, the design of the container is relatively compact. The fact that the container can be placed horizontally and has a compact design makes it easy to arrange the container in the desired position relative to the patient. When a ves ¬ sel of the known type mentioned by way of introduction is used, this is normally arranged in the patient's head region. The head region, however, is normally overloaded with other components, which means that the relative- ly compact container is easier to place in said region. Moreover the container can be arranged in some other position relative to the patient since the risk of leakage when someone happens to knock against the container is eliminated. According to an embodiment of the invention (not shown) , the externally opening end of the outlet 2 of the container is designed so as to be able to hold a syringe. The syringe can be used for, for instance, rinsing of the container with water or air through the outlet. As appears from Figs 6 and 7, the pressure compensating function of the air duct 8 can also be maintained when the container is oriented in a second or third position. This change of position causes no leakage as long as the surface level of the fluid 6 is below the level of the outlet 3, i.e. as long as the level of the fluid does not reach the outlet 3. More specifically, the arrows in Fig. 6 indicate that the container serves as a valve for letting gas through also when the container is inclined while simultaneously collecting fluid 6. Even if the container is directed with the inlet 2 downwards, as in Fig. 7, the valve and collecting function of the container is guaranteed. At a possible positive pressure in the patient's stomach (not shown), gas indicated by the arrows will be supplied to the container through the air duct 8. As the gas enters the container through the inlet 2, the gas will rise through the fluid 6 and final- ly leave the container through the outlet 3. Fluid 6, such as gastric juice, which enters the container through the air duct 8 will be collected by the container in a leakage-free manner as long as the surface level of the fluid 6 is not above the level of the outlet 3. Preferably, the container is made of a flexible material. The container will then be compressible, thereby permitting its volume to be reduced. By a suitable blocking and opening of the outlet 3 of the container as the container is being compressed, the following func- tions can be achieved: (i) By first compressing the container, subsequently blocking the outlet 3, then unloading the container so that it resumes its original shape, and finally opening the outlet 3, the pressure can be decreased in the stomach (not shown), whereby e.g. gastric juice or gas can be sucked out of the stomach. (ii) By first blocking the outlet 3, subsequently compressing the container, then opening the outlet 3 and finally unloading the container, the pressure can be increased in the stomach (not shown), whereby e.g. gastric juice or gas can be pressed into the stomach. (iii) By first blocking the outlet 3, subsequently compressing the container, then unloading the container, and finally opening the outlet 3, any undesired material that has happened to get stuck in the air duct 8 can be pressed out. The above-described container can thus, according to the present invention, be used as a vessel for chemical processes, in which gas generates. The container then ensures pressure compensation between the surroundings and the container while the container can be turned or rotated, without any risk of leakage of the fluid in the container as long as its surface level is below the level of the outlet. The inventive container also allows leakage-free collection of fluid while simultaneously allowing a two- way pressure compensating function of a tube, whose one end is connected to the inlet of the container and whose other end opens into a closed volume. When the container is contained in a dual-lumen gastric probe and is used for collecting gastric juice and for gas exchange, a dual-lumen gastric probe is provided, which is easy and reliable to handle. The simple function of the container permits handling by a patient, whereby a patient equipped with an inventive dual-lumen gastric probe can be granted leave during which the patient himself takes care of the handling of the container. Although but a few embodiments of the invention have been described, it goes without saying that other embodi ¬ ments are feasible. It is possible to obtain the outlet 3 of the container by means of a duct 10 which extends into the container, as illustrated in Fig. 8. In this case, the duct 10 has a first end 11 opening centrally inside the container, and a second end 12 opening outside the container. The essential thing thus is that the container has a centrally arranged internal outlet 3. The invention is also not limited to the shown oval shape, but other shapes are conceivable. Finally, it is of course possible to use the present invention in applications other than those describ- ed above. In particular, other applications than medical ones, such as the above-described dual-lumen gastric probe or drainage of the urinary bladder of a patient, are conceivable. For instance, the present invention can also be used for leakage-free collection of oil leaking from a machine component of a mechanical device in motion. It will thus be appreciated that the present invention is usable in any application in which adjustment of the pressure in a volume to the pressure prevail ¬ ing in the surroundings is required and in which spillage of liquid from the volume to the surroundings should be prevented independently of the orientation of the liquid- collecting or liquid-keeping container. All modifications and variations within the scope of the invention are thus considered to be comprised by the accompanying claims .

Claims: CLAIMS 1. A device for making a connection between a volume and the surroundings, comprising an air duct (8) for pressure compensation between the volume and the surroundings, c h a r a c t e r i s e d by a container which is connected to the air duct (8) and which has a centrally arranged outlet (3) opening into the surroundings, whereby fluid (6), which through the air duct (8) is transferred from the volume to the container, is collected in a leakage-free manner by the container, inde- pendently of its orientation, as long as the surface level of the fluid (6) is below the level of the outlet (3) while simultaneously allowing said pressure compensation. 2. A device as claimed in claim 1, c h a r a c - t e r i s e d in that one side of the container is designed such that an area of the side is arranged centrally in the container, in which area the outlet (3) is formed. 3. A device as claimed in claim 2, c h a r a c - t e r i s e d in that the side in which the outlet (3) is formed consists of the bottom of the container. 4. A device as claimed in claim 3, c h a r a c t e r i s e d in that the bottom has the shape of a funnel (5), which extends into the container, the outlet (3) being formed in the narrow end of the funnel (5) , said narrow end being arranged centrally in the container. 5. A device as claimed in claim 1, c h a r a c t e r i s e d in that a duct (10) extends into the con ¬ tainer, the duct having a first end (11) opening central- ly in the container and forming said outlet (3), and a second end (12) opening outside the container. 6. A device as claimed in any one of the preceding claims, c h a r a c t e r i s e d in that the outlet (3) has an externally opening end which is designed to be able to hold a syringe. 7. A device as claimed in any one of the preceding claims, c h a r a c t e r i s e d in that the container is essentially oval in cross-section. 8. A device as claimed in any one of the preceding claims, c h a r a c t e r i s e d in that the container is made of a transparent material. 9. A device as claimed in any one of the preceding claims, c h a r a c t e r i s e d in that the container is made of a flexible material. 10. A device as claimed in any one of the preceding claims, c h a r a c t e r i s e d in that said air duct (8) constitutes the air duct (8) of a dual-lumen gastric probe for making a connection between the surroundings and a patient's stomach, said container being arranged for leakage-free col- lection of gastric juice (6) while simultaneously allowing pressure compensation between the stomach and the surroundings . 11. A method for making a connection between the surroundings and a volume, comprising the step of con- necting, with the aid of a first duct means, the volume with the surroundings such that a pressure prevailing in the surroundings is also obtained in the volume, c h a r a c t e r i s e d by the step of forming a portion of the first duct means, said portion comprising at least part of the first duct means, as a centrally arranged outlet (3) of a container, said outlet opening into the surroundings, whereby said pressure compensation is ensured independently of the orientation of the container, without any risk of leakage of a fluid (6) in the container as long as the surface level of the fluid (6) is below the level of the outlet (3) . 12. A method as claimed in claim 11, c h a r a c t e r i s e d by the step of connecting, with the aid of a second duct means (8), the volume with an inlet (2) of the container, which together with the second duct means (8) forms said first duct means, whereby fluid (6) leaving the volume through the second duct means (8) is collected by the container in a leakage-free manner independently of its orientation, as long as the surface level of the fluid (6) is below the level of the outlet (3) while simultaneously allowing said pressure compensation. 13. A method as claimed in claim 11, c h a r a c t e r i s e d by the step of letting the volume be formed of said container, which thus in a leakage-free manner keeps fluid (6) independently of its orientation as long as the surface level of the fluid (6) is below the level of the outlet (3) while simultaneously allowing said pressure compensation through said first duct means, which thus is formed of the outlet (3) of the container .

Inventors: LUNDGREN LARS-GOERAN, LUNDGREN, LARS-GOERAN
Applicants: LUNDGREN LARS GOERAN, LUNDGREN, LARS-GOERAN
Application year: 1998
Main classification: A61M25
IPC codes: A61J15