Control Wire Ratchet Assembly for Precise Distal End Positioning

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Solution Overview

Problem

Existing medical devices, such as endoscopes, suffer from inaccuracies in positioning due to slack in control wires causing hysteresis and lack of responsiveness, leading to incorrect positioning of the distal end and attached instruments.

Innovation Solution

A ratchet assembly is integrated into the actuator mechanism to maintain continuous tension on control wires, combining a coarse control mechanism with a fine control mechanism to ensure precise manipulation of the distal end, using a ratchet adjuster and ratchet teeth to eliminate slack and enhance responsiveness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If control wires are used to manipulate the distal end of the shaft, then the medical device can be operated manually through the actuator, but slack in the wires causes hysteresis and positioning inaccuracy

Engineering Contradiction:

Improvemanual operationVSAvoidpositioning accuracy

Core Design Contradiction:

Ease of operationVSMeasurement precision

Solution Approach 1:

The ratchet assembly pre-tensions the control wires before manipulation begins, eliminating slack and hysteresis in advance. This preliminary action ensures that the wires are always under tension, providing immediate and accurate response to actuator movements without the delay caused by slack wire take-up.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system dynamically changes the tension parameter of the control wires using the ratchet assembly. By maintaining continuous tension through the ratchet mechanism, the physical state of the wires changes from a slack condition to a continuously tensioned state, thereby improving the linearity and accuracy of the relationship between actuator movement and distal end positioning.

Inventive Principle:

Principle #35Parameter changes

2Ease of operation

If knobs or thumb sliders are used for actuator manipulation, then the device can be controlled, but positioning accuracy is reduced due to slack-induced hysteresis

Engineering Contradiction:

Improveactuator controlVSAvoidpositioning precision

Core Design Contradiction:

Ease of operationVSManufacturing precision

Solution Approach 1:

The ratchet assembly applies preliminary tension to the control wires before the actuator is manipulated, eliminating the hysteresis that would otherwise cause positioning errors. This pre-tensioning action ensures that the control system responds immediately and accurately to user input without the delays associated with slack wire take-up.

Inventive Principle:

Principle #10Preliminary action

3Device complexity

If a simple take-up wheel mechanism is used, then the device structure remains simple, but slack in the wires causes delayed response and inaccurate positioning

Engineering Contradiction:

Improveactuator structureVSAvoidpositioning reliability

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The ratchet assembly performs preliminary tensioning of the control wires, eliminating slack and hysteresis before the manipulation cycle begins. This preliminary action ensures reliable and immediate response to actuator movements, significantly improving positioning reliability without requiring complex electronic control systems.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The invention replaces potential electronic or complex mechanical control systems with a simple mechanical ratchet assembly that provides continuous wire tension. This mechanical substitution achieves reliable positioning control through pure mechanical means, maintaining structural simplicity while dramatically improving response reliability.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The ratchet assembly provides accurate and responsive control over the distal end of medical devices, reducing positioning errors and enhancing the precision of medical instrument placement.

Implementation Method 1

Methodology Applied

Scientific EffectRatchet mechanism: Ratchet

Data Source

PatentUS20260053337A1Method and apparatus for manipulating a control wire of a medical device

Publication Date: 2026.02.26 TANGENT ENDOSCOPY LLC

AI summary

A method and apparatus for manipulating a control wire in a medical device comprising a control wire take-up wheel being rotatable to provide coarse control wire manipulation and a ratchet assembly, coupled to the control wire take-up wheel and coupled to the control wire, to provide fine control wire manipulation.