The invention relates to a self-advancing device particularly, but not exclusively, for use in the field of medical instrumentation.
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.
Self-advancing endoscopes are disclosed in, for example, U.S. Pat. Nos. 4,934,786, 5,345,925 and 5,562,601. The devices disclosed in these patents all rely on the outer surface of the endoscope having a relatively movable portion that grips the internal wall of a passage through which the endoscope is passing. 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.
Another endoscope is disclosed in International Application No. PCT/AU99/00005, which is propelled forwardly by a piston slidably mounted within a tubular member of the endoscope. The piston is caused to move toward and impact on a distal end wall of the endoscope to provide forward motion. A wire or other mechanism is used to retract the piston for subsequent acceleration and impact with the end wall, in order to further advance the endoscope. 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.
The present invention seeks to provide a self-advancing device which addresses the above disadvantages.
One or more embodiments provide for a device which includes an elongate body with a movable mass arranged for sliding movement within the body. The moveable mass may be arranged to decelerate toward an end of the body in order to impart forward movement thereto, via momentum transfer. The moveable mass may further be arranged to accelerate away from the end in order to further drive the body forward also using momentum transfer. The device may also define a first flow path for applying pressurised fluid to a rear of the moveable mass and a second flow path for allowing the fluid to be discharged from between a front of the moveable mass and the end of the body. Fluid flow along the second flow path may be reduced as the moveable mass approaches the end of the body, in order to provide a fluid cushion to dampen impact between the moveable mass and the body. A third flow path is provided to inject fluid between the moveable mass and the end of the body, in order to accelerate the moveable mass in a rearward direction relative to the end of the body.
In further embodiments, a method of generating movement in the above-described device is provided. The method includes including rapidly decelerating the moveable mass toward an end of the body to impart forward movement thereto, via momentum transfer and accelerating the moveable mass away from said end in order to further drive the body forward, again using momentum transfer, by injecting fluid between the moveable mass and the end of the body.
The invention is described, by way of non-limiting example only, with reference to the accompanying drawings, in which:
A self-advancing device 1 is shown in
In operation, a first flow path 21 is established to force fluid into the first region 9 between the rear end 11 of the body 2 and the element 4, to drive the element 4 toward the front end 13 of the body 2. At the same time, a second flow path 22 is established to drain fluid from the second region 15, between the front end 12 of the element 4 and the end 13 of the body 2. In that manner, the element 4 may be accelerated toward the front end 13 of the body 2. Relative inertia between the element 4 and the body 2 maintains the device 1 in place up until the element 4 is adjacent the end 13 of the body 2, as determined by sensor 16, at which time, the element 4 is rapidly decelerated. The change in momentum is transferred to the body 2 so as to overcome the relative inertia of the body 2 and impart forward motion thereto. The deceleration is effected in such a manner that the fluid in the second region, between the front end 12 of the element 4 and the body 2 acts to dampen an impact between the element 4 and the body 2 itself. The dampening effect may be achieved by regulating the fluid flow along the second flow path 22.
A second working cycle is then implemented, in which the element 4 is rapidly accelerated away from the front end 13 of the body 2 by injecting high-pressure fluid along a flow path 23 through the conduit 6 and into the second region 15, between the front end 13 of the element 4 and the body 2, so that the inertia of the body is again overcome, to allow the body 2 to again move in a forwardly direction, indicated by arrow “A”. The element 4 is then decelerated and brought to a stop, once it is proximate to the rear end 10 of the body 2, as detected by sensor 17, so as to position the element 4 for commencement for another working cycle.
The specific construction of the device, which allows flow paths 21,22,23 to be defined, as well as the dynamic regulation of fluid flow along those flow paths, constitutes an overall control means which provides for control of the fluid flow between the element 4 and the body 2 to thereby effect the frequency and rate of deceleration or acceleration, as required, in order to move the device. The control means may also be used to cause reverse motion of the device by essentially reversing the direction of the working cycles.
A more specific example of the working cycles is described with reference to
Referring now to
As the element 4 approaches the rear end 11 of the body 2, additional valves 48 are contacted and forced open to allow for egress of any remaining fluid in the region 9 between the rear 11 of the body 2 and a rear 10 of the element 4. The valves 44 are subsequently opened and the first fluid flow path 51 is again established to accelerate the element 4 toward the front end 13 of the body 2.
The above described self-advancing device 1,40 may be used to propel any suitable probe or the like and, in particular, the device may be fitted to an endoscope 60, such as shown in
The same principle of momentum transfer may be used to drive a catheter or angioscope 60, such as shown in
The invention may, accordingly, be utilised in any suitable application or field such as where a remotely actuable self-advancing probe is required, either in the medical, surveillance or other relevant fields such as inspection and or maintenance of pipelines, cable and wire hoses, and search and rescue operations.
Further, it should be appreciated that many alterations and variations may be made without departing from the spirit and scope of the invention. For example, the body 2 of the device may be either rigid or flexible, as described with reference to
The device 1,40 or probe can be propelled with the energy delivered from an external source via flexible means for example—pipe, electric wire/cable, fiber optic cable and/or mechanical flexible wire etc. If the self-advancing probe (endoscope, angioscope or catheter) advances in a medium with changes in path topology such as bends, increased resistance and friction, the average cycle speed of repetitive moving mass (piston) motion has to be adjusted to ensure advancing properties. The probe can be a self containing unit with the propellant or energy source attached to the body of the probe—for example—the probe is propelled by the linear motion electromagnetic motor (solenoid, etc.)—the probe itself, control device and set of batteries can be encapsulated into one unit. The self-advancing probe (endoscope, angioscoope, catheter) may serve as a vehicle for delivery of functional devices such as sensory and surveillance devices, manipulators, containers, communication, lighting and dosing devices etc.
Number | Date | Country | Kind |
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PR9678 | Dec 2001 | AU | national |
PS0647 | Feb 2002 | AU | national |
PS1610 | Apr 2002 | AU | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/AU02/01733 | 12/20/2002 | WO | 00 | 9/13/2004 |
Publishing Document | Publishing Date | Country | Kind |
---|---|---|---|
WO03/053225 | 7/3/2003 | WO | A |
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Number | Date | Country | |
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20050165278 A1 | Jul 2005 | US |