Self-advancing device

Abstract

A device which includes an elongate body with a movable mass arranged for sliding movement within the body is disclosed. The element is arranged to decelerate toward an end of the body in order to impart forward movement thereto, via momentum transfer, and is further arranged to accelerate away from said end in order to further drive the body forward, again using momentum transfer.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application is a continuation of U.S. application Ser. No. 10 / 499,426 filed Sep. 13, 2004 (issued on Jan. 27, 2009 as U.S. Pat. No. 7,481,764), which is a National Stage application of PCT Application No. PCT / AU02 / 01733, filed on Dec. 20, 2002, which claims priority to Australian Patent Application Nos. PS 1610 / 02 (filed on Apr. 8, 2002), PS 0647 / 02 (filed on Feb. 21, 2002), and PR 9678 / 01 (filed on Dec. 20, 2001). Each of the above-referenced applications is incorporated by reference in its entirety.BACKGROUND[0002]1. Field[0003]The invention relates to a self-advancing device particularly, but not exclusively, for use in the field of medical instrumentation.[0004]2. Description of the Related Art[0005]A number of self-advancing mechanisms are used in the medical industry to advance instruments, such as an endoscope, internally of a patient's body.[0006]Self-advancing endoscopes are disclosed in, for example, U.S. Pat. No. 4,934,786...

AI Technical Summary

Benefits of technology

[0011]The device may define a first flow path for applying pressurized fluid to a rear of the element and a second flow path for allowing the fluid to be discharged from between a front of the element and the end of the body, wherein fluid flow along the second flow path is reduced as the element approaches the end of the body, in order to provide a fluid cushion to dampen impact between the element and the body. A third flow path may also be provided to inject fluid between the element and the end of the body, in order to accelerate the element in a rearward direction relative to the end of the body, fluid flow along the third flow path being established when the element is adjacent the end of the body.

Problems solved by technology

In that manner, the endoscopes rely on external pushing as their source of forward motion and the resultant construction of the mechanisms to achieve that motion can be relatively complex.

A disadvantage of such an arrangement is that the impact of the piston can produce an uncomfortable sensation within the patient and the use of a retracting wire may complicate construction of the endoscope and compromise operating efficiency, such as due to frictional resistance between the tubular member and the wire.

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