Patent Description:
A problem with the arrangement described in the above is that the passage or air through the filter is impeded if an additional filter is used in connection with diathermy, or the filter is partly blocked as a result of fluid having splashed in the filter.

<CIT> discloses a canister lid for a canister includes an annular perimeter surrounding an interior portion. The annular perimeter is interrupted by a suction conduit defined by a suction duct separating a first lobe and a second lobe. The suction duct intersects the annular perimeter such that the first lobe is disposed interior of the annular perimeter while the second lobe is disposed exterior to the annular perimeter. The canister lid can further include one or more ports extending from the interior portion.

<CIT> discloses a patient fluid collection system which includes a fluid collection reservoir, a cover for the reservoir and a liner within the reservoir comprising an enlargeable or expandable wall portion such that the wall portion may expand if the liner fills with fluid.

Further, a suction bag with a lid and a filter in connection with a negative pressure channel is described in <CIT>.

It is therefore an object of the invention to develop a suction bag in which the aforementioned problems have been solved. The object of the invention is achieved by a suction bag and suction bag arrangement which are characterised by what is disclosed in the independent clams.

The suction bag according to the invention is used in connection with medical or surgical operations to suck fluid from the suction target. The suction target is usually a patient being operated on. The volume of the suction bag is often <NUM> to <NUM>. The advantage of the inventive suction bag is that air flows well also in such situations where an additional filter is used in connection with diathermy between the filter and sleeve, or when fluid being sucked has splashed onto the bottom surface of the filter.

In the following, the suction bag and suction bag arrangement are described in their operating positions.

The suction bag comprises a bag portion and a lid fixedly connected thereto. In other words, the bag portion is permanently mounted to the lid so that the bag portion and lid cannot be separated from each other without breaking the structure. The lid may be an integral piece whereby the lid, excluding the filter, is formed of the same material. Usually, the plastic material of the lid is polypropylene. The plastic material of the bag portion is usually polyethene. The lid is stiff as to its material whereas the bag portion is flexible.

The suction bag has a connection for the suction target and a connection for negative pressure. The connection for the suction target is usually realized by a so-called patient connection formed in the lid. By using the patient connection, it is however possible to suck fluid from other targets than a patient; for example, fluid that has leaked onto a floor of an operating theatre may be sucked from it. The patient connection may have on it a detachable angle connector for a patient tubing.

The connection for negative pressure in usually a channel formed at an edge of the lid, continuing inside the lid. The lid comprises a filter installation recess, on the underside of the lid, where the aforementioned channel joins. The installation recess had a filter through which the negative pressure acts on the inside of the suction bag and induces suction on the target being sucked through the patient connection.

The filter installed in the installation recess is cylindrical. The shape of the cross section of the installation recess differs from circular. Its shape may be oblong or another shape different from circular. The installation recess is surrounded by a sleeve having another cross section than circular, the cross section of which has the diameter of the widest point and the cross section of the narrowest point. The cross section of the sleeve may be oblong or another shape differing from circular. The diameter of the cross section of the sleeve at its widest point is at least <NUM>% larger than the diameter of its narrowest point. The diameter of the cross section of the sleeve at its widest point may be <NUM> to <NUM>% larger than the diameter of its narrowest point, advantageously it is <NUM> to <NUM>% larger than the diameter of its narrowest point, and the most advantageously <NUM> to <NUM>% larger than the diameter of its narrowest point. Usually, the diameter of the widest point is at least <NUM>% larger than the diameter of its narrowest point. The diameter of the cross section of the widest point may be <NUM>% larger than the diameter of its narrowest point, advantageously it is at least <NUM>% larger than the diameter of its narrowest point, and the most advantageously it is at least <NUM>% larger than the diameter of its narrowest point. Usually, the cross section of the widest point is no more than <NUM>% larger than the diameter of its narrowest point, advantageously it is no more than <NUM>% larger than the diameter of its narrowest point, and the most advantageously it is no more than <NUM>% larger than the diameter of its narrowest point.

The aforementioned percentages P are calculated by using the outer diameter d1 of the widest point of the sleeve and the outer diameter d2 of the narrowest point of the sleeve so that P = ((d1-d2)/d2) * <NUM>. The calculation is carried out at the precision of two decimals so that the third decimal is rounded up, if the third decimal to be omitted is <NUM>, <NUM>, <NUM>, <NUM>, or <NUM>, and the third decimal is rounded down, if the third decimal to be omitted is <NUM>, <NUM>, <NUM>, or <NUM>. The widest diameter and narrowest diameter of the sleeve may be at any angle in relation to each other. The measurement is naturally carried out through the centre point of the filter. The diameters may be, for example, substantially perpendicular to each other, as an oblong shape requires, or the widest and narrowest diameter may be at an angle less than <NUM>° in relation to each other.

The invention will now be described in more detail in connection with preferred embodiments and with reference to the accompanying drawings, in which:.

<FIG> illustrate the same embodiment of the invention, that is, the details shown in these figures all belong to one and the same suction bag or suction bag arrangement. Some of the illustrated details are not essential, which means that they are so presented that they may be included in the structure.

The suction bag arrangement comprises a suction bag <NUM> and a canister <NUM>. A bag part <NUM> of the suction bag <NUM> is installed inside the canister <NUM> so that a lid <NUM>, fixedly connected to the bag part <NUM>, closes the canister <NUM>. The lid <NUM> has a groove <NUM> inside which the edge of the canister <NUM> positions itself. In the vicinity of the groove <NUM> there may be protrusions in the portion of the lid <NUM> going inside the canister <NUM>, which prevent installing a suction bag <NUM> of a wrong size in the canister. An option is that there are protrusions at even intervals on the perimeter of the lid <NUM> going inside the canister and lid <NUM> contacting the wall of the canister <NUM>.

The lid <NUM> of the suction bag <NUM> has a patient connection <NUM> which may have preinstalled on it an angle connector <NUM> of the patient connection. A hose coming from a patient and carrying fluid sucked from the patient is connected to the patient connection <NUM> through the angle connector <NUM>. The patient connection <NUM> may also be used to convey fluid sucked from other targets to the suction bag <NUM>. Such a target may the floor of an operating theatre, for example.

The patient connection <NUM> may be closed by a plug <NUM> of the patient connection, which is fixed to an edge of the lid <NUM> by a cord <NUM>. On the side of the plug <NUM>, which stays outside the lid <NUM> when the patient connection <NUM> is closed with the plug <NUM>, there may be a circular groove which has ribs <NUM> in the direction of the radius of the plug. The ribs <NUM> prevent the plug <NUM> from being fixed directly to the angle connector <NUM> of the patient connection <NUM>. The cord <NUM> may be toothed in its longitudinal direction whereby it is flexible and easy to bend when the patient connection <NUM> is to be closed by the plug <NUM>.

The canister <NUM> has a negative pressure connection <NUM> which may have preinstalled on it an angle connector <NUM> of the negative pressure connection, to which the suction tube of a negative pressure source is hooked up. From the negative pressure connection <NUM>, a negative pressure channel <NUM> of the canister starts, which is in contact with a negative pressure channel <NUM> of the suction bag <NUM> in the lid <NUM> of the suction bag and a space between the suction bag <NUM> and canister <NUM>. The negative pressure acts on the inside of the suction bag <NUM> through a porous filter <NUM>. The filter <NUM> is a cylindrical piece installed in an installation recess <NUM> at the mouth of the negative pressure channel <NUM> inside the suction bag <NUM>. The filter <NUM> closes up when the fluid level reaches the bottom surface 10b of the filter <NUM>. At this time, negative pressure suction also stops influencing.

The filter <NUM> is surrounded by a sleeve <NUM>. There is a gap <NUM> between the inner wall of the sleeve <NUM> and outer surface of the filter <NUM>, in which gap an additional filter may be installed. The shape of the cross section of the sleeve <NUM> differs from circular. The shape differing from circular contributes to good air passage in special situations, too, such as in connection with the use of an additional filter, or when the filter <NUM> is partly clogged even though the suction bag <NUM> is not yet full. In other words, negative pressure suction works normally regardless of the special situation because the shape of the cross section of the sleeve <NUM>, which differs from circular, leaves room for air to flow between the cylindrical filter <NUM> and sleeve <NUM>.

The diameter of the cross section of the sleeve <NUM> at its widest point is at least <NUM>% larger than the diameter of its narrowest point. The diameter of the cross section of the sleeve at its widest point may be <NUM> to <NUM>% larger than the diameter of its narrowest point, advantageously it is <NUM> to <NUM>% larger than the diameter of its narrowest point, and the most advantageously <NUM> to <NUM>% larger than the diameter of its narrowest point. Usually, the diameter of the widest point is at least <NUM>% larger than the diameter of its narrowest point. The diameter of the widest point may be <NUM>% larger than the diameter of its narrowest point, advantageously it is at least <NUM>% larger than the diameter of its narrowest point, and the most advantageously it is at least <NUM>% larger than the diameter of its narrowest point. Usually, the cross section of the widest point is no more than <NUM>% larger than the diameter of its narrowest point, advantageously it is no more than <NUM>% larger than the diameter of its narrowest point, and the most advantageously it is no more than <NUM>% larger than the diameter of its narrowest point.

The sleeve <NUM> is measured on the side of its outer surface. Because the material thickness of the sleeve <NUM> is substantially invariable, the measurement provides reliable information also on the widest and narrowest diameter of the inner surface of the sleeve <NUM>.

The lid <NUM> may have a series connection <NUM> which may be closed by a plug <NUM> of the series connection. The series connection <NUM> may be used to connect suction bags in series, for sampling, dosage of a solidifier, and manual emptying.

The lid <NUM> may also have a place <NUM> for attaching an accessory. Furthermore, the lid <NUM> may have markings on it for installing the suction bag <NUM> to the canister <NUM> so that the suction bag <NUM> can be correctly and easily installed in place.

When the suction bag <NUM> is removed from the canister <NUM>, the suction bag <NUM> may have a removal rib <NUM>. The removal rib <NUM> is turned upwards so that protrusions <NUM> at the base of the removal rib <NUM> support themselves on the edge of the lid <NUM>, whereby the edge of the lid <NUM> rises to some extent, and air from outside the canister <NUM> may flow into the canister <NUM>.

<FIG> illustrate measuring the widest diameter d1 and narrowest diameter d2 of the sleeve <NUM>. In <FIG>, the cross section of the sleeve <NUM> is an ellipse, whereby the widest diameter d1 and narrowest diameter d2 are perpendicular to each other. The measurement is carried out on the external surface 11a of the sleeve. The diameters d1 and d2 pass through the centre point 10a of the filter <NUM>. A gap <NUM> remains between the outer surface of the filter <NUM> and inner surface of the sleeve <NUM>.

In <FIG>, the cross section of the sleeve <NUM> is geometrically irregular whereby the widest diameter d1 and narrowest diameter d2 are at an angle less than <NUM>° in relation to each other. The measurement is carried out on the external surface 11a of the sleeve. The diameters d1 and d2 pass through the centre point 10a of the filter <NUM>. A gap <NUM> remains between the outer surface of the filter <NUM> and inner surface of the sleeve <NUM>.

Claim 1:
A suction bag (<NUM>) for medical or surgical use, the suction bag (<NUM>) having a connection (<NUM>) for a suction target and which suction bag (<NUM>) comprises a bag portion (<NUM>) and, fixedly connected thereto, a lid (<NUM>) which comprises a negative pressure channel (<NUM>) for leading negative pressure suction to the suction bag, an installation recess (<NUM>) on the underside of the lid (<NUM>) for a filter (<NUM>), surrounded with a sleeve (<NUM>), and a cylindrical filter (<NUM>) installed in the installation recess (<NUM>) in connection with the negative pressure channel (<NUM>), characterized in that the cross section of the sleeve (<NUM>) differs in shape from circular so that the outer diameter (d1) of its widest point is at least <NUM>% larger than the outer diameter (d2) of its narrowest point.