Surgery – Means for introducing or removing material from body for... – Treating material introduced into or removed from body...
Patent
1986-10-21
1988-11-15
Truluck, Dalton L.
Surgery
Means for introducing or removing material from body for...
Treating material introduced into or removed from body...
604 96, 604230, 604 93, 128DIG25, 138172, A61M 2500
Patent
active
047846518
DESCRIPTION:
BRIEF SUMMARY
This invention concerns catheters of the kind used for drainage of the bladder via the urethra. Most known forms of urethral catheter consist of a rigid or semi-rigid tube which is inserted into the bladder to effect rapid or controlled drainage thereof, the tube having openings at both ends. Such catheters serve as constant drainage devices wherein the tube remains open and is designed to resist any appreciable degree of collapse or compliance with the shape of the urethra, the latter being non-circular and tending towards a narrow slit.
Another form of the urethral catheter is described in patent specification GB No. 2113554, and consists of a thin-walled preformed tube of a material which will readily approximate in cross-section to the shape of the urethral lumen such that it will undergo substantially complete collapse under normal urethral pressure thus to comply with the irregular and slit-like lumen but permit adequate distension for normal drainage.
Whilst a thin-walled catheter tube of the aforementioned type has the required property of lateral compliance, it has limited resistance to longitudinal flexion. If the tube is bent along its axis as is likely in catheterisation it can kink and thus prevent the passage of urine.
A further difficulty with the thin-walled design is the tendency for the wall to collapse in the prostatic region when used for male catheterisation. In this region it is necessary for the tube to possess a degree of resistance to both lateral collapse and longitudinal bending.
An object of the present invention is to provide a thin-walled urethral catheter having one or more zones of increased flexural resistance for satisfactory performance in certain applications.
According to the present invention there is provided a urethral catheter comprising a tube having openings at both ends, and having in at least a portion of that part of the tube to be situated within the urethra, a flexural wall formation, and at least one zone of increased stiffness extending along said portion such that, according to the intended use, either longitudinal flexion is reduced or flexural compliance in a lateral direction is reduced, or both.
The tube in the aforesaid portion will have a pre-formed cross-section to which it will return elastically in an unstressed state. If the zone of increased stiffness is formed by increasing the wall thickness there should be substantially no axial or peripheral discontinuity on the inner wall surface of the tube, which should be a smooth approximation to an oval form. The wall is not supported by internal struts or by ridges or grooves, which could decrease the compliance of the catheter when collapsing within the urethra or even prevent its collapse and which could reduce the lumen area available for drainage and provide a wall more likely to encrust and become infected. The reduced lateral compliance and longitudinal flexion is to be provided by increased wall stiffness in certain selected areas.
Examples of uretheral catheters embodying the invention will now be described with reference to the accompanying drawings in which:
FIG. 1 is a cross-section of a so-called thin-walled catheter having a longitudinal inflation tube for a Foley balloon; as described in GB No. 2113554;
FIGS. 2a to 2d are cross-sections of thin-walled thin-walled catheter tubes each having at least one zone of increased stiffness extending along at least a portion of the length of the tube, in accordance with the invention;
FIGS. 3a to 3c are further cross-sections of thin-walled catheter tubes each having at least one zone of increased stiffness extending along at least a portion of the length of the tube; and
FIGS. 4a and 4b are partial views of catheters embodying the invention and usable for male and female patients respectively.
Referring now to the drawings, in FIG. 1 the tube wall generally shown at 10 is produced from a flexural and resilient material which is clinically acceptable and sufficiently durable in use, and is preferably in the region of 0.2 mm thick. Examples of mater
REFERENCES:
patent: 1596754 (1926-08-01), Moschelle
patent: 4180076 (1979-12-01), Betancourt
patent: 4553959 (1985-11-01), Hickey et al.
patent: 4571241 (1986-02-01), Christopher
patent: 4601713 (1986-07-01), Fugua
The Victoria University of Manchester
Truluck Dalton L.
Whelton Denise
LandOfFree
Urethral catheter does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Urethral catheter, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Urethral catheter will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1101605