Robotic Surgical Instrument Pulley System for Load Management

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Solution Overview

Problem

Robotic surgical instruments face inefficiencies and potential damage due to unwanted movement, such as tilting, when subjected to high loads during minimally invasive procedures, which can reduce the precision and effectiveness of surgical operations.

Innovation Solution

The design incorporates a pulley system with sections of varying diameters to restrict movement, including a first section with a groove and a second section with a smaller diameter, configured to interfere with the supporting body, limiting its movement and preventing interference with pulleys, thereby maintaining the efficiency of the end effector.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If the supporting body is allowed to move freely under high loads, then the instrument can accommodate heavy loads (>10N), but unwanted movement and tilting occur that reduce precision and efficiency

Engineering Contradiction:

Improveload capacityVSAvoidsurgical precision

Core Design Contradiction:

ForceVSMeasurement precision

Solution Approach 1:

The pulley is divided into two distinct sections: a first section with a larger diameter that allows the supporting body to rotate freely during normal operation, and a second section with a smaller diameter that acts as a mechanical stop to prevent excessive tilting under high loads. This segmentation enables the system to accommodate both free movement and load-bearing requirements.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different sections of the pulley have different diameters to provide different functional properties. The first section (larger diameter) provides smooth rotation for precision operations, while the second section (smaller diameter) provides mechanical constraint to limit tilting angle under heavy loads, ensuring surgical precision is maintained even when supporting the body weight.

Inventive Principle:

Principle #3Local quality

2Reliability

If the end effector supports heavier loads to hold tissue in place, then tissue stabilization is improved, but obstruction or interference with driving elements occurs that reduces efficiency

Engineering Contradiction:

Improvetissue stabilizationVSAvoidsurgical efficiency

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The pulley's two-section design segments the rotational freedom from the tilting constraint. The first section allows sufficient rotation for driving elements to operate efficiently, while the second section prevents excessive tilting that would cause interference with driving elements, thus maintaining both tissue stabilization and surgical efficiency.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The pulley diameter parameter changes along its length, creating a gradient from larger to smaller diameter. This parameter change enables the system to accommodate the supporting body's rotation while limiting the maximum tilting angle, preventing interference with driving elements even when heavy loads are applied for tissue stabilization.

Inventive Principle:

Principle #35Parameter changes

3Force

If the supporting body tilts under high loads, then load bearing is maintained, but tension in components is reduced leading to poor movement transfer

Engineering Contradiction:

Improveload bearing capacityVSAvoidcomponent tension

Core Design Contradiction:

ForceVSStrength

Solution Approach 1:

The two-section pulley structure segments the motion control: the first section accommodates rotation while the second section acts as a mechanical stop to limit tilting. This ensures that even under heavy loads (>10N), the supporting body cannot tilt excessively, maintaining tension in the components and ensuring proper movement transfer throughout the instrument.

Inventive Principle:

Principle #1Segmentation

4Measurement precision

If a pulley system is added to restrict movement, then unwanted tilting is reduced, but device complexity increases

Engineering Contradiction:

Improvemovement controlVSAvoidinstrument structure

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The movement restriction function is merged into the pulley structure itself rather than being a separate component. The two-section pulley combines the rotation accommodation function and the tilting prevention function into a single integrated element, reducing overall device complexity while maintaining precise movement control.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The two-section pulley performs multiple functions: it acts as a rotation guide for the supporting body, a mechanical stop to limit tilting angle, and a structural element that maintains tension in components. This multi-functionality reduces the need for additional separate components, keeping the instrument structure relatively simple.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS20240341868A1A robotic surgical instrument

Publication Date: 2024.10.17 CMR SURGICAL LTD

AI summary

There is provided a robotic surgical instrument comprising an end effector, a shaft component, a supporting body connected to a distal end of the shaft component at a first end and to the end effector at a second end, and a pulley facing an outer surface of the first end of the supporting body. The pulley comprises a first section with a first diameter and a second section with a second diameter that is smaller than the first diameter. The first or second section of the pulley is configured to restrict movement of the supporting body.