Biological navigation device

Abstract

A biological navigation device that can be attached or integrated with an elongated element, such as a colonoscope, is disclosed. The device can be used for navigation through a biological lumen. The device can have an everting tube controllably tearable substantially in the direction of the long axis of the device. The elongated element can be deployed through a channel formed in the inner virtual space of the channel extending along the long axis.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application is a continuation-in-part of PCT Application Nos. PCT / US08 / 52535, filed 30 Jan. 2008; and PCT / US08 / 52542, filed 30 Jan. 2008; which claim the benefit of U.S. Provisional Application Ser. Nos. 60 / 887,319, filed 30 Jan. 2007; 60 / 887,323, filed 30 Jan. 2007; and 60 / 949,219, filed 11 Jul. 2007, all of which are incorporated herein by reference in their entireties.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The presented invention relates generally to devices for the exploration of luminal cavities. One such device example is an endoscope, which can be used to explore body passages. Such passages typically include, but are not limited to, the GI tract, the pulmonary and gynecological systems, urological tracts, and the coronary vasculature. One application is directed towards the exploration of the lower part of the GI tract, for example the large intestine or colon.[0004]2. Description of the Related Art[0...

AI Technical Summary

Benefits of technology

[0037]The sheath can stay clamped together, for example, for the face sealed sheath, and / or for example when the everting tube driving, pressure exceeds internal pressures and forces (e.g., fluid / air / solid element passage forces). The sheath can have indexing elements that can minimize or prevent lateral motion or sliding, for example, to further prevent the sheath from separating. As the sheath everts at the tip, there are geometries which interface such that the everting tube lumens connect to tip geometries and their lumens. For example, a short, thin wall tube section can extend backwards from the tip, penetrating one of the lumens. This interaction ensures the relatively continuous passage of lumen elements through to the proper tip interaction and ultimate exit.

[0046]The colonoscopy system can have a controller. The controller can control the pump. The controller can execute one or more algorithms to modulate the operating pressure of the pump. The controller can be connected to pressure sensors in the colonoscopy system. The controller can be connected to sensors that detect the length that the colonoscope has extended. For example, these algorithms can start the operating pressure at a given value, then increase the pressure as the extended length of the colonoscope increases. The algorithms can reduce the pressure during retraction or withdrawal of the colonoscope. The algorithms can increase system reliability and efficacy, and reduce the operators cognitive load.

[0049]The sheath and / or everting element can be made from PTFE, a plastic, LDPE, including multiple ‘low stiction’ blends, Nylon (including use of Nylon-on-Nylon), or of composite construction, including with reinforced members. Lubricants can be applied to the sheath and / or everting element, for example to reduce drag / friction. The lubricants can include fluids such as water, glyercine (glycerol), other glycol-based fluids, vegetable oils, silicones, graphites (e.g., with superlubricity properties), PAO (poly-alpha-olefin), dispersions including of lubrous materials such as Boron Nitride (BN), colloidal dispersions of PTFE. Molybdenum disulfide coatings and additives in lubricants can be applied to the sheath and / or everting element. Dry film coatings can be applied to the sheath and / or everting element. Synthetic fluids and mineral (petroleum-based) fluids can be applied to the sheath and / or everting element. The fluids can be biocompatible and non-toxic, such as skin-contact friendly.

Problems solved by technology

However, as disposable and other lower-cost colonoscopes are developed, these articulatable sections are no longer practical.

Their high part count creates total costs that are exorbitant for a lower cost, disposable device.

The pivot pins can also fall out, which can create a patient danger.

Their design geometries, while suited for long life, high cost, high strength metals elements, don't readily suit themselves to the design goals of lower-cost and more readily mass-produced parts.

Navigating the long, small diameter colonoscope shaft in compression through the colon—a circuitous route with highly irregular anatomy—can be very difficult.

Even with the achievement of such a practice milestone, the cecum is often not reached, thereby denying the patient the potential for a full diagnosis.

During colonoscopy, significant patient pain can result.

The primary cause of pain is thought to be stretching and gross distortion of the mesocolon (the mesentery that attaches the colon to other internal organs).

While attempting to advance the tip by pushing on the scope, often all that occurs is that intermediate locations are significantly stretched and grossly distorted.

Anesthesia delivery results in the direct cost of the anesthesia, the cost to professionally administer, the costs associated with the capital equipment and its facility layouts, and the costs associated with longer procedure time (e.g., prep, anesthesia administration, post-procedure monitoring, and the need to have someone else drive the patient home).

Cleaning of colonoscopes is also an issue.

Cleaning is time consuming, and lack of proper cleaning can result in disease transmission.

Cleaning also creates significant wear-and-tear of the device, which can lead to the need for more servicing.

However, multiple challenges exist for everting systems.

One typical challenge is the differential speed between the center lumen and the tip.

This can make it difficult to try to solve the 2:1 problem in a typical everting tube by sliding elements in the inner diameter or central region.

This 2:1 advancement issue and the pressure clamping can make it difficult to locate traditional colonoscope tip elements at the everting tip's leading edge.

Given that the tube is often long and pressurized, it therefore often precludes the ability to create a functioning center working channel.

Another issue is internal drag.

Material (e.g., tube wall) fed to the tip can cause increased capstan drag, for example the overall system advance force can be retarded to the point of stopping extension.

Optimal material selection is a highly significant challenge.

Monolithic materials have proven insufficient at providing the variety of requisite specifications.

It can be difficult to create a system that is of adequately low stiffness.

Larger diameters create higher propulsive forces, but they also do not typically readily conform to the colon in a lumen-centric manner and can be overly stiff.

This is time consuming and creates an undesirably non-continuous and geometrically interrupted procedure.

It is also very difficult to create ‘correct’ undesirable relative motion to a deflated structure that essentially is no longer a structure.

However, it has yet to be commercialized, it is very complicated, creates an undesirably larger diameter instrument, has lubrication leakage issues, and breaks down at longer advance lengths.

Additionally, colonoscopic devices have found it notably challenging to create methods to appropriately navigate through torturous geometries, particularly without undue colon wall stresses and subsequent mesocolon stretch.

Steering kinematics are critical and have been an ongoing challenge—certainly for existing colonoscopes (which result in ‘looping’), but also to more effective next-generation devices.

When a propulsion tube section's leading edge then has a steering section more distal, with typically a camera, lighting source, and working channel exit at the tip, the steering is less than effective when going around a corner: A situation is created in which the tip is retroflexed and is pointing in one desired direction of advance, but the system's advance is in an exactly opposite direction.

In a colonoscopy, this wall interaction is undesirable—it creates unnecessary wall stress and trauma, and can be a significant contributor to gross wall distortion, known as looping.

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