Patent Application
20240016997
The invention relates to an anal probe for use in an irrigation system.
The accompanying drawings are included to provide a further understanding of embodiments and are incorporated into and a part of this specification. The drawings illustrate embodiments and together with the description serve to explain principles of embodiments. Other embodiments and many of the intended advantages of embodiments will be readily appreciated as they become better understood by reference to the following detailed description. The elements of the drawings are not necessarily to scale relative to each other. Like reference numerals designate corresponding similar parts.
Embodiments relate to an anal probe for use in an anal irrigation procedure, the anal probe comprising—
An anal probe as described above has the advantage of being very easy to use, since the retention part is built in and requires no manipulation from the user. The anal probe is self-sealing without the need to inflate a balloon.
In the following, whenever referring to a proximal end of an element of the invention, the referral is to the end adapted for insertion. Whenever referring to the distal end of an element, the referral is to the end opposite the insertion end. In other words, the proximal end is the end closest to the user, when the probe is to be inserted and the distal end is the opposite end—the end furthest away from the user when the probe is to be inserted.
The longitudinal direction is the direction from the distal to the proximal end. The transverse direction is the direction perpendicular to the longitudinal direction, which corresponds to the direction across the stem of the probe.
By radial extent is meant an extent in a transverse direction extending from one outer surface directly across in the transverse direction to the opposite outer surface.
An irrigation system typically comprises a reservoir or container for irrigation liquid, an anal probe and tubing connecting those two. The system may also include a pump for pumping the irrigation liquid into the intestines. When a self-sealing anal probe as described herein is used in an anal irrigation system, the system does not require an extra tube nor an extra pump for filling a balloon used as retention means. Therefore, the system can be simpler, when an anal probe as described herein is used.
The anal probe comprises a stem in the form of a tubular part extending from the distal end towards the proximal end. The tip portion is positioned in the proximal end of the stem. The probe may comprise a connector in the distal end of the stem.
The retention part is attached, connected or moulded to an attachment portion of the stem, which is between the proximal tip portion of the stem and the distal end of the stem. A central bore in the retention part is configured for being brought into contact with the attachment portion of the stem and the two parts are fixedly attached, connected or moulded together. The retention part increases in circumference from its distal portion towards the proximal portion of the retention part. The largest circumference of the retention part will be between approximately mm and 220 mm corresponding to a radial extent across the retention part in the transverse direction between 5 mm and 70 mm. Larger retention parts having a radial extent up to 75 mm may be contemplated.
The tubular part of the stem has a diameter of 5-10 mm.
Distal portion of the retention part is defined as the portion of the retention part, which is attached to the stem at an attachment portion of the stem.
Proximal portion of the stem is defined as the portion of the stem, which extends proximally beyond the attachment.
The stem may be made of Polyethylene, Polypropylene, or a combination of a TPE with a harder material such as PE, PP or ABS. The stem may also be made of Polyurethane.
The retention part may be made of a soft resilient material.
The retention part may be made of foam, for example a polyurethane foam. The foam should be rather soft and compliant, but also function as self-sealing. An example of a suitable foam is RAKU-PUR® 31-3173. Another example could be a foam as the one used in Biatain® wound dressings marketed by Coloplast A/S.
A soft resilient material, such as foam, will have the beneficial effect of providing a self-sealing probe. This is because the resilient material will naturally conform to the bowel and when liquid is in the bowel on the proximal side of the retention part, this liquid will assist in pressing the flare of the retention part outwards such that the largest radial extent and circumference of the retention part may increase.
Furthermore, in examples where the retention part is made of foam, the foam may be saturated by the irrigation liquid and will (also) in this way increase the sealing towards the inside of the bowel.
The retention part may also be made of silicone.
The materials suitable for this purpose may have a hardness in the Shore 00 range of between 20 and 50.
If a sealing film is used as an impermeable layer, a thin Polyurethane film may be used. Examples of thicknesses are between 5 to 250 μm, such as 30 or 50 μm.
An examples of a complete probe is a probe where the stem, the retention part and the sealing film are all made of Polyurethane.
The retention part of the anal probe described herein may be compressed to a smaller diameter in a transverse direction, such that the diameter in a compressed configuration is around 20% of the diameter in a use configuration. The compressed configuration may be supported by a film-element, which is wrapped around the retention part to keep it in that configuration. This makes the probe easier to insert. The use configuration, where the retention part is unfolded or uncompressed is required for providing a better sealing to the bowels during the irrigation procedure. The diameter, or the radial extent of the retention part in the compressed configuration may be 25% or 30% or lower such as 15% or 10% of the radial extent of the retention part in a use configuration.
In an embodiment, the proximal tip portion is an open tip. In other words, the inside lumen of the stem ends in an open end, so that irrigation liquid exits the proximal tip portion directly through the open end. The open end may simply be cut-off or it may be slightly rounded at the end of lumen so as to provide an atraumatic tip. During insertion of the probe, a user may inadvertently poke the probe around slightly; therefore, it is an advantage if the proximal end of the probe is atraumatic.
In an embodiment, the proximal tip portion is a closed tip. This means that the inside lumen of the stem is closed off in the proximal end and a sidewall of the proximal tip portion is provided with at least one eyelet for allowing irrigation liquid to exit the proximal tip portion. More than one eyelet may be used, such as two or three. The proximal closed end of the proximal tip portion may be rounded, or it may be flat or angled. If the closed end of the proximal tip portion is the proximal end of the anal probe, it may be an advantage that the closed end is rounded, because this will provide an atraumatic proximal end of the probe.
On the other hand, if the proximal tip portion is not the proximal end of the anal probe, then the closed end may be of any shape, because this end will be situated within the retention part.
A closed proximal tip portion may be an advantage because the liquid exiting the proximal tip portion will exit in a diffused manner by forcing the liquid to exit sideways of the probe and then be directed proximally by the retention part. Diffusing of the liquid will prevent any direct spraying of the liquid at the inside of the bowels, which in extreme circumstances may cause trauma to the bowels.
The eyelets may be 1-5 mm wide and 2-6 mm long. In this context the width is transverse to the probe and the length is the longitudinal direction of the probe.
Embodiments relate to the retention part being funnel-shaped. This means that the retention part flares out from a distal portion of the retention part to the proximal end of the retention part, such that a radial extent at the proximal end is larger than a radial extent of the distal portion.
Embodiments relate to the retention part being bowl-shaped. This means that the retention part has a middle port with a radial extent larger than the radial extent of the distal portion and the radial extent of the proximal end. In other words, a circumference of the retention part increases from a first circumference in a distal portion to a second circumference in a middle portion and the decreases again to a third circumference in a proximal end.
Embodiments relate to a radial distance from an outer surface of the proximal tip portion to an inner edge of the proximal end of the retention part being at least 5 mm. This embodiment leaves room for the liquid to leave the proximal tip portion of the stem without being too much interfered or even obstructed by retention part.
In an embodiment, a distal surface of the retention part is impermeable to liquid. By impermeable to liquid is meant that leakage through the retention part is less than 5 ml/min. A leakage in that order, i.e. less than 5 ml/min, will allow the irrigation liquid to stay in the bowels for approximately 5 minutes, which is contemplated to be adequate for the irrigation procedure to be effective.
Embodiments relate to the impermeability being due to the retention part being coated on an outer surface. The coating can be done by dipping or spraying.
Embodiments relate to the impermeability being due to a layer of film-material being added to the retention part on an outer surface thereof. The layer may be vacuum-drawn onto the retention part or thermoformed onto the retention part. Alternatively, the film layer can be manufactured in a specific shape adapted for being put on the retention part.
Embodiments relate to the impermeability being due to a moulded part being added to the retention part on an outer surface thereof. This may be of silicone or TPE and being injection moulded in a shape configured to be put on the retention part.
Embodiments relate to the impermeability being due to the foam having a skin, which is impermeable. The skin may be made during the foaming process, where it is possible to make the outer surface as a closed skin instead of an open-celled structure.
Embodiments relate to the impermeability being due to the foam being a closed cell foam, whereby all of the foam element constituting the retention part is impermeable to liquid.
Embodiments relate to the probe being provided with a film-element configured for keeping the probe in a storage configuration, in which the retention part of the probe is compressed, such that a radial extent of the probe in the storage configuration is smaller than a radial extent of the probe in the use configuration. A smaller diameter may be around 1 cm, such as between 8 mm and 12 mm. The retention part of the probe is able to be compressed because it is made of a soft resilient material. In examples, a retention part of foam is able to be compressed to a small diameter, such as mentioned above.
In embodiments, where the probe comprises foldable arms, these are, in the storage configuration, folded up inside the probe such that the probe can be compressed.
Embodiments relate to the film-element being made of a water-soluble film. Water-soluble films are known from e.g. dishwasher tabs and may be made of Polyvinyl Alcohol (PVA).
If the film-element is made of a water-soluble film, the user does not have to unpack it prior to inserting it. The user just has to insert the probe while it is wrapped in the film, and then the film will dissolve by itself. The process of dissolving the film-element will typically take between 5 and seconds. This process will occur as a result of the liquid being naturally present in the bowel. The dissolving process may be enhanced, if the retention part is made of foam and becomes saturated by the irrigation liquid, because the irrigation liquid will permeate through the retention part to the distal surface of it and assist in dissolving the water-soluble film.
Initially, it shall be noted that the figures are schematic illustrations intended only to address the principles and functions of the anal probe described herein and are not to be considered limiting to the scope of the attached claims. Furthermore, the figures and particularly the individually illustrated elements are not necessarily to scale, neither individually nor in relation to each other.
The retention part 30 is here funnel shaped. Towards, the bottom of the funnel, at the distal portion 31, the retention part is attached to the attachment portion 11 of the stem. This is best seen in
In
In
In the anal probe 400 of this figure, the retention part 430 is not funnel-shaped but rather shaped as a bowl. This means that the retention part still has a radial extent 432 at a distal portion, which is smaller than a radial extent 433 at a position proximally to that, e.g. at a middle portion 437. However, at a proximal end 434 (at the rim of the retention part), the radial extent 438 of the retention part is smaller than the radial extent of the middle portion 437. As can be seen from
Embodiments, and features of the various exemplary embodiments described in this application, may be combined with each other (“mixed and matched”), unless specifically noted otherwise.
Four parameters were tested on different types of anal probes. The aim was to determine how to make an anal probe that performed acceptably on these four parameters. The parameters are:
In Table 1 below, the target values for the different parameters are shown.
These target values are based on testing of a known anal plug (Conveen® Anal Plug, marketed by Coloplast A/S) and considerations of factors in relation to use of an anal probe.
For the vertical and radial pull-out forces, accepted values are considered to be lower than 15 N. This is based on testing a prior art product, the Conveen® anal plug marketed by Coloplast A/S. The Conveen® anal plug has a vertical pull-out force of 12 N and a radial pull-out force of 10 N. The drop out pressure of the Conveen® anal plug is around 600 mbar. The leakage through the anal plug is very high, because it is not constructed to prevent leakage of liquid.
There is a balance between the drop out pressure, which should be as high as possible and the pull-out force, which should be low—in particular in a radial direction. A high pull-out force in a radial direction could potentially lead to trauma in the anal opening during pull-out of the anal probe.
The sealing against leakage has to be close to zero. An acceptable level is considered to be around 5 ml/min. If this is not the case, then the anal probe will not be able to keep the irrigation inside the bowel for the necessary time (around 5 minutes or more).
A lower limit for the drop out pressure is around 150 mbar—the pressure inside the bowel will rarely exceed this value in a normal functioning bowel.
Various anal probes were tested, and the four parameters were noted.
The first two parameters—pull out force and radial force were tested in a test rig as shown in
The test rig comprises a bowl-shaped holder, in which the test specimen (e.g. the anal probe) was inserted during testing. The test rig used was a standard tension testing machine, which was connected to two load cells measuring the vertical pull-out force and the radial pull-out force, respectively. The test was done such that the machine-head moved vertically upward by a test speed of 5 mm/s. The tested probes were lubricated prior to testing, so as to simulate the surface of the catheter during insertion and pull-out into the rectum of a user.
The parameters of leakage and drop-out pressure were tested in a test rig as shown in
Testing of various probes show that probes with retention parts made of foam with no impermeable outer surface will not perform well with respect to leakage. The leakage through such a probe may be up to 1000 ml/min or more, which is clearly above target. However, if a foam probe is provided with an impermeable layer, e.g. in the form of a thin film, it is possible to reach an acceptable level of leakage—or even as low as close to zero leakage.
With respect to the pull-out force in vertical and radial direction, tests show that it is possible to reach levels of around 5-7 N or even as low as 3 N, for retention parts made of foam with or without foldable arms to support it. The lower values are obtained for probes as in
| Number | Date | Country | Kind |
|---|---|---|---|
| PA 2020 70779 | Nov 2020 | DK | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/DK2021/050343 | 11/24/2021 | WO |
