MANUFACTURE OF MEDICAL DEVICES AND SUCH A MEDICAL DEVICE

Abstract

Improvements relating to the Manufacture of Medical Devices The present invention relates to medical devices and methods of manufacturing medical devices. The application describes method of manufacturing a medical device where at least one insert (20,22) is provided with a first sheath including an inner sheath body (24) and one or more sheath projections (26), such that the insert (20,22) and the first sheath can be supported by the one or more sheath projections (24) within a mould chamber, and a second sheath (28) is injection moulded about the inner sheath body (24) and the at least one insert (20,22), between the one or more sheath projections (26).

Claims

1. A method of manufacturing a medical device, comprising the following steps: (a) providing at least one insert and a first sheath for the at least one insert, the first sheath including an inner sheath body and one or more sheath projections, (b) providing a second injection moulding tool having a second mould chamber, (c) locating the at least one insert and the first sheath within the second mould chamber, such that the at least one insert and the first sheath are supported within the second mould chamber by the one or more sheath projections, and (d) injection moulding a second sheath about the inner sheath body and the at least one insert, between the one or more sheath projections.

2. The method as claimed in claim 1, wherein the method comprises the following preceding steps: (a) providing a first injection moulding tool having a first mould chamber, the first mould chamber having one or more support projections extending inwardly into the chamber, (b) locating at least one insert within the first mould chamber, such that the at least one insert is supported by the one or more support projections, and (c) injection moulding a first sheath about the at least one insert, the first sheath including an inner sheath body and one or more sheath projections.

3. The method as claimed in claim 1, wherein the one or more support projections of the first mould chamber cause the first sheath to include openings, through which the at least one insert is exposed following injection moulding of the first sheath, and the injection moulding of the second sheath extends into and fills those openings.

4. The method as claimed in claim 1, wherein the exterior surface of the second sheath is substantially flush with the end surfaces of the one or more sheath projections.

5. The method as claimed in claim 1, wherein one or more sheath projections protrude beyond the exterior surface of the second sheath.

6. The method as claimed in claim 1, wherein the medical device comprises at least one insert and a combined sheath, where the combined sheath consists of the first and second sheaths, and the exterior surface of the sheath is provided with a smooth exterior.

7. The method as claimed in claim 1, wherein the at least one insert comprises a unitary element or a plurality of elements, such as a bundle of fibres.

8. The method as claimed in claim 1, wherein the at least one insert may be readily shaped by a user, eg using finger pressure only, and may retain its shape once deformed.

9. The method as claimed in claim 1, wherein the medical device has the form of a stylet or bougie, which is insertable through a tracheal tube.

10. The method as claimed in claim 1, wherein the first mould chamber has a plurality of support projections, and the at least one insert is retained or clamped between the support projections.

11. The method as claimed in claim 1, wherein the at least one insert is elongate in form, and the plurality of support projections are disposed along the length of the at least one insert at substantially regular intervals.

12. The method as claimed in claim 1, wherein a set of support projections are provided at positions along the at least one insert, with each set of projections retaining or clamping the at least one insert, and each set of support projections comprises at least projections on each side of the at least one insert.

13. The method as claimed in claim 1, wherein the one or more support projections have a cross-sectional shape, eg an elliptical or rectangular shape, that has an increased dimension substantially in the direction of the longitudinal axis of the at least one insert.

14. The method as claimed in claim 1, wherein the one or more sheath projections of the first sheath extend outwardly from the inner sheath body.

15. The method as claimed in claim 1, wherein the one or more sheath projections project substantially perpendicularly relative to the longitudinal axis of the at least one insert.

16. The method as claimed in claim 1, wherein the first sheath has a plurality of sheath projections, and the at least one insert and the first sheath are adapted to be supported on an inner surface of the second mould chamber by the sheath projections, such that the inner sheath body does not contact a surface of the second mould chamber.

17. The method as claimed in claim 1, wherein the at least one insert is elongate in form, and a plurality of sheath projections are disposed along the length of the at least one insert.

18. The method as claimed in claim 1, wherein a set of sheath projections are provided at positions along the at least one insert, with each set of projections being retained or clamped between inner surfaces of the second mould chamber.

19. The method as claimed in claim 1, wherein each set of sheath projections comprises projections at substantially regularly spaced intervals, circumferentially of the at least one insert.

20. The method as claimed in claim 1, wherein the second sheath has a substantially uniform cross-section.

21. The method as claimed in claim 1, wherein the second sheath extends about the one or more sheath projections, such that the one or more sheath projections are surrounded, save for end surfaces.

22. The method as claimed in claim 1, wherein the exterior surface of the combined sheath, formed by the first and second sheaths, is substantially uniform.

23. The method as claimed in claim 1, wherein the end surfaces of the one or more sheath projections act as visual indicators, in use.

24. The method as claimed in claim 1, wherein the materials of the first and second sheaths have contrasting visual features.

25. The method as claimed in claim 1, wherein the at least one insert defines a malleable portion of the device, and the device also includes an integrally-formed, relatively flexible portion of the device, which is formed in the same injection moulding step as the second sheath.

26. The method as claimed in claim 1, wherein the second sheath extends beyond the at least one insert to define a relatively flexible portion of the device.

27. The method as claimed in claim 25, wherein the cross-sectional shape and dimensions of the relatively flexible section are substantially the same as the cross-sectional shape and dimensions of the malleable section.

28. The method as claimed in claim 1, wherein the device is adapted for use as a guide or introducer for a tracheal tube.

29. The method as claimed in claim 1, wherein the device comprises a stylet portion and a bougie portion.

30. A medical device manufactured by the method as claimed in claim 1.

31. The medical device as claimed in claim 30, wherein the device comprises at least one insert surrounded by a first injection-moulded sheath, said first sheath comprising an inner sheath body and one or more sheath projections.

32. The medical device as claimed in claim 31, wherein the device further comprises a second injection-moulded sheath that surrounds the inner sheath body, extending between the one or more sheath projections.

33. The medical device as claimed in claim 32, wherein the end surfaces of the one or more sheath projections are substantially flush with the exterior surface of the second sheath.

34. The medical device as claimed in claim 30, wherein the device comprises at least one malleable portion, which includes the at least one insert, and at least one flexible portion.

35. The medical device as claimed in claim 34, wherein the malleable and flexible portions define different longitudinal sections of the device.

36. The medical device as claimed in claim 30, wherein the device has the form of a bougie and/or stylet, and comprises at least a first malleable portion, longitudinally intermediate a flexible distal tip and a proximal flexible portion.

37. The medical device as claimed in claim 36, wherein the device comprises a second malleable portion, such that the first and second malleable portions are separated by an intermediate flexible portion.

38. The medical device as claimed in claim 30, wherein the device is a toothbrush.

39. The medical device as claimed in claim 30, wherein the device is a tube support.

Description

[0040] An embodiment of the invention will be described in further detail below, by way of example only, with reference to the accompanying drawings, of which:

[0041] FIG. 1 is a cross-section view of a device according to the invention;

[0042] FIG. 2 is an enlarged cross-sectional view of a portion of the device;

[0043] FIG. 3 is an enlarged side view of a portion of the device;

[0044] FIG. 4 is a cross-sectional view of the device in an intermediate stage of manufacture; and

[0045] FIG. 5 is a plan view of the device in an intermediate stage of manufacture.

[0046] The device, as shown in FIG. 1, comprises a flexible proximal end 10, a first malleable section 12, an intermediate flexible section 14, a second malleable section 16, and a flexible distal end 18.

[0047] The length of the device may be between 400 and 800 millimetres, eg approximately 650 mm. The diameter of the apparatus may be between 3 and 10 millimetres.

[0048] The first malleable section 12 and the second malleable section 14 comprise metal rods 20, 22, which are surrounded by inner sheaths 24, 26 formed of a plastics material, eg LDPE. The inner sheaths 24, 26 are surrounded by a plastic material, in the form of an outer sheath, that makes up the flexible proximal end 10 and distal end 18, and the intermediate section 14.

[0049] The device can be used as both a bougie and a stylet. In a first configuration, the device is configured for use as a bougie, with the first malleable section 12 being bent to form a handle, and after insertion of the flexible distal end 18 into the trachea, the operator can railroad a tracheal tube over the flexible proximal end 10 and into the trachea. In a second configuration, the device is configured for use as a stylet where the second malleable section 14 is pre-formed and a tracheal tube is pre-loaded over the device. In this configuration, a handle may be formed by bending the flexible proximal end 10.

[0050] FIG. 2 shows an enlarged view of the first malleable section 12. The rod 20 is a thin, elongate metal rod. The inner sheath 24 surrounds the rod 20. The rod 20 and inner sheath 24 are generally cylindrical, with the inner sheath 24 being concentric to the rod 20. The inner sheath 24 comprises projections 26 which extend from the surface of the inner sheath 24. The projections 26 are spaced along the length of the inner sheath and extend from regularly-spaced locations around the circumference of the inner sheath 24.

[0051] The outer sheath 28 surrounds the inner sheath 24 and the metal rod 20, such that the outer sheath 28 is concentric with the inner sheath 24 and the rod 20. The outer sheath 28 is made of the same material as the flexible portions of the device. The device is moulded such that the outer sheath 28 is unitary with the flexible portions of the device; the outer sheath 28 and flexible portions are moulded in a single injection moulding process. The inner sheath 24 does not cover the ends 30, 32 of the rod 20, however the ends 30, 32 of the rod 20 are surrounded by the outer sheath 28, which in this position is thicker, such that the surface of the device is smooth, and the diameter of the device is substantially uniform.

[0052] The outer sheath 28 surrounds the inner sheath 24, such that its exterior surface is flush with the end surfaces of the projections 26 of the inner sheath 24, and the projections 26 are thus exposed, as shown in FIG. 3.

[0053] FIG. 4 shows a cross-sectional view of a partial device during an intermediate stage of manufacture. The rod 20 and inner sheath 24 are shown, before the stage of manufacture in which the outer sheath 28 and flexible portions are moulded around the rod 20 and inner sheath 24. A top view of the partially constructed apparatus is shown in FIG. 5.

[0054] As shown in FIGS. 4 and 5, the inner sheath 24 comprises openings 36, which are intermediately spaced between the projections 26. During manufacture of the inner sheath 24, the rod 20 is held in place by pins which contact the rod 20 in the position of the openings; the inner sheath 24 is created by injection moulding, and the plastic is injected into the mould such that it surrounds the rod 20 and the pins holding the rod 20 in place. The pins hold the rod 20 in place in the mould such that the inner sheath 24 is concentric to the rod 20.

[0055] During the stage of manufacture of the outer sheath 28 of the device, the outer sheath 28 is injection moulded around the inner sheath 24 such that the outer sheath 28 enters the openings 36 and surrounds the projections 26. The ends 34 of the projections hold the rod 20 and inner sheath 24 in place in the mould, such that the thickness of the outer sheath 28, around the rod 20 and the inner sheath 24, is uniform along the length of the outer sheath 28 and around the circumference of the outer sheath 28.

[0056] FIG. 6(a) shows a cross-section though the rod 20 and the inner sheath 24, through a set of sheath projections 34, and FIG. 6(b) shows the same cross-section following injection moulding of the outer sheath 28. The exterior surfaces of the outer sheath 28 and the sheath projections 34 are co-extensive, and flush with each other.

[0057] FIG. 6(c) shows a cross-section though the rod 20 and the inner sheath 24, through a set of openings 36, and FIG. 6(b) shows the same cross-section following injection moulding of the outer sheath 28. The outer sheath 28 extends into, and fills, the space that was previously defined by the openings 36.