Steerable Medical Device Connector Collinear Actuation

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional steerable medical devices face challenges in minimizing the outer size of the bendable sheath while maximizing the inner diameter of tool channels, and they suffer from difficulties in quickly connecting and disconnecting the sheath due to backlash and loss of driving forces caused by perpendicular moving directions between driving wires and the actuation unit.

Innovation Solution

A medical robotic system with a bendable-body assembly that includes a bendable body, driving wires, and a connection receptor, featuring a connecting shaft with driving-wire guides and locking pins, allowing for linear and rotational motion to minimize backlash and maintain actuation force, enabling quick and efficient connection and disconnection of the sheath.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If a connector cartridge with perpendicular moving directions between driving wires and actuation unit is used, then the connection can be made, but the connector assembly becomes difficult to miniaturize and creates relatively large loss of driving forces

Engineering Contradiction:

Improveconnector assembly sizeVSAvoiddriving force loss

Core Design Contradiction:

Volume of moving objectVSLoss of energy

Solution Approach 1:

The patent inverts the conventional perpendicular connection approach by using a collinear arrangement where the driving wire moves in the same direction as the actuation unit. This inversion eliminates the need for bending the driving wire at right angles, thereby reducing connector size and minimizing driving force loss while maintaining effective force transmission.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent transitions from a two-dimensional perpendicular connection (where driving wire and actuation unit move in orthogonal directions) to a one-dimensional collinear connection (where both move along the same axis). This dimensional simplification reduces the spatial requirements of the connector and eliminates force loss associated with directional transformation.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Measurement precision

If a connector cartridge with perpendicular moving directions is used, then the connection can be established, but backlash and slack of driving wires occur making it difficult to finely manipulate the bendable sheath

Engineering Contradiction:

Improvemanipulation precisionVSAvoidbacklash and slack

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

By inverting the connection geometry from perpendicular to collinear, the patent eliminates the mechanical bending of the driving wire that causes backlash and slack. The direct linear connection ensures taut wire operation and eliminates the play and non-taut operation characteristic of perpendicular connections, thereby improving manipulation precision and reliability.

Inventive Principle:

Principle #13The other way round (Inversion)

3Quantity of substance

If the bendable sheath has minimal wall thickness to minimize outer size and maximize inner diameter, then the tool channel size increases, but the connection and disconnection process becomes more critical for ensuring sterility

Engineering Contradiction:

Improvetool channel inner diameterVSAvoidconnection and disconnection speed

Core Design Contradiction:

Quantity of substanceVSEase of operation

Solution Approach 1:

The collinear connection design simplifies the connection and disconnection mechanism by eliminating complex perpendicular movements and wire bending. This streamlined approach enables faster and more reliable connection/disconnection operations, which is critical for maintaining sterility when using thin-walled disposable sheaths.

Inventive Principle:

Principle #13The other way round (Inversion)

Data Source

PatentUS11730349B2Steerable medical device with bending sections and improved connector therefor

Publication Date: 2023.08.22 CANON USA INC

AI summary

Embodiments of a robotic medical system comprise a steerable instrument that includes a bendable body and a connector assembly configured to detachably connect the bendable body to an actuation unit. A controller is configured to control the actuation unit. The connector assembly comprises a connection receptor coupled to the actuation unit and a connecting shaft coupled to the bendable body. The connecting shaft includes a plurality of driving rods that are attached in a one-to-one correspondence to a plurality of driving wires and that detachably attach to the connection receptor. In a connected state where the bendable body is connected to the actuation unit via the connector assembly, the controller causes the actuation unit to transmit an actuating force from an actuator to a driving rod, and the driving rod actuates or moves a driving wire in a same direction as the actuating force applied by the actuator.