Endoscope assemblies having working channels with reduced bending and stretching resistance

Abstract

Apparatus and methods for endoscope assemblies having working channels with reduced bending and stretching resistance are disclosed. In one embodiment, an endoscope assembly includes a sheath having a body portion adapted to at least partially encapsulate an endoscopic insertion tube, and a working channel attached to the body portion and extending along at least a portion of the body portion. The working channel includes a component for reducing the resistance of the assembly to bending and stretching. In alternate aspects, the working channel may include a cut, a gap, a sliding portion, or an expansion section. Endoscope assemblies having a working channel in accordance with the invention advantageously reduce the articulation and stretching resistance of the assembly during articulation of the endoscope assembly. Also, because the axial forces (tension and compression) within the working channel are reduced, the working channel can be fabricated out of a relatively hard, inelastic material, thereby reducing the friction within the working channel and improving the physician's ability to perform a medical procedure.

Description

TECHNICAL FIELD [0001] The present invention is directed toward endoscopic apparatus and methods, and more specifically, to endoscope assemblies having working channels with reduced bending and stretching resistance. BACKGROUND OF THE INVENTION [0002] Endoscopes are widely used for a variety of medical procedures. To improve their performance, endoscopes have been optimized in various ways to best accomplish their purpose. Examples of specialized endoscopes include angioscopes, colonoscopes, bronchoscopes, and arthroscopes. [0003] One of the medical procedures that may be performed using an endoscope is obtaining a biopsy sample. FIG. 1 shows a conventional endoscope assembly 10 used for obtaining a biopsy sample. The endoscope assembly 10 includes an endoscope 20 having an elongated insertion tube 22. The insertion tube 22 may be rigid, partially flexible, or entirely flexible. The insertion tube 22 includes a distal portion 24 that may be inserted into a body cavity of a patient (...

AI Technical Summary

Benefits of technology

[0014] Endoscope assemblies having a working channel in accordance with the invention advantageously reduce the bending and stretching resistance of the assembly during articulation of the endoscope assembly, thereby reducing the tension on the articulation control cables. Also, because the axial forces (tension and compression) within the working channel are reduced, the working channel can be fabricated out of a relatively hard, inelastic material, thereby reducing the friction within the working channel and improving the physician's ability to perform a medical procedure.

Problems solved by technology

Although desirable results have been achieved using the conventional devices described above, some drawbacks do exist.

Generally speaking, however, such known flexible materials have high coefficients of friction that inhibit the movement of medical instruments through the working channel.

In some situations, such as at a sharp bending corner along the insertion tube, the medical instrument may be unable to progress through the working channel, or may even become stuck, necessitating the removal of the insertion tube.

Unfortunately, the lining of relatively-hard corrugated material greatly increases the thickness of the wall of the working channel, and thus, the overall diameter of the endoscope assembly.

Thus, the sheath having a working channel lined with a relatively-hard corrugated material may increase the discomfort or trauma experienced by the patient, or may not be practical for some medical procedures due to size constraints within the patient's body.

Also, the cost of manufacturing the working channel lined with the relatively-hard corrugated material is undesirably high.

Finally, although the corrugated channel does stretch axially, it does not do so easily.

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