Torque-Actuated End Effector Through a Sterile Barrier
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In minimally invasive surgical settings, there is a challenge in transmitting torque through a sterile barrier without damaging it, especially when connecting a sterile surgical instrument to a robot arm, as existing solutions either risk damaging the barrier or require expensive mechanical joints.
Innovation Solution
A system comprising a tool with a rotor unit and a stator unit, where the rotor unit is connected to a drive shaft and can rotate relative to the proximal end, and the stator unit induces rotation of the rotor unit through radial forces, allowing torque transmission without twisting the sterile barrier, using a brushless DC motor system and cammed regions for efficient rotation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a sterile barrier is used to protect the surgical instrument, then sterility is maintained, but torque transmission is hindered and the barrier may be damaged
Solution Approach 1:
A magnetic coupling system acts as an intermediary between the sterile and non-sterile sides of the barrier. The rotor unit with magnets on the sterile side interacts with corresponding magnets on the non-sterile side through the barrier, transmitting torque without mechanical contact or penetration of the barrier itself.
Solution Approach 2:
The patent replaces direct mechanical torque transmission through the barrier with a magnetic field-based transmission system. The magnetic interaction allows torque to be transmitted across the barrier without physical twisting or penetration, eliminating the mechanical stress that would damage the barrier.
2Ease of operation
If a mechanical joint is provided in the sterile barrier to transmit torque, then torque transmission is enabled, but the complexity and cost of the system increases significantly
Solution Approach 1:
The patent eliminates complex mechanical joints by substituting them with a magnetic coupling system. The magnetic interaction between rotor and stator units provides smooth torque transmission without the need for mechanical connectors, reducing complexity and potential failure points.
Solution Approach 2:
The magnetic field serves as an intermediary that transmits torque without requiring direct mechanical connection. This eliminates the need for complex mechanical joints while maintaining effective torque transmission across the sterile barrier.
3Productivity
If the sterile instrument is connected directly to the robot flange, then torque transmission is efficient, but sterility is compromised due to contact with potentially contaminated objects
Solution Approach 1:
The system is divided into sterile and non-sterile segments separated by the barrier. The rotor unit with magnets is placed on the sterile side, while the corresponding magnets are on the non-sterile side. This segmentation allows torque transmission while maintaining the sterility boundary.
Solution Approach 2:
The sterile barrier acts as an intermediary that separates the sterile instrument from the non-sterile robot flange. The magnetic coupling system transmits torque through this intermediary without compromising either sterility or transmission efficiency.
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
Enables effective torque transmission through a sterile barrier without damaging it, maintaining sterility and reducing the need for expensive mechanical joints, facilitating safe and efficient robotic surgical procedures.
Implementation Method 1
the body (410) of the rotor unit (400) is disposed with at least two cammed regions each configured to receive radial force from the stator unit (500) that induces rotation of the body (410) around the axis of rotation
Implementation Method 2
a drive shaft (402), at least partially flexible for transfer of torque from the proximal end (20) to the end effector (300)
Data Source
AI summary
Provided is a system comprising a tool (50) and a stator unit (500). The tool (50) comprises an instrument (100, 102) having a proximal end (20) and a distal (40) end, an end effector (300) at the distal end (40) actuated by torque, and a rotor unit (400) body (410) having at least two cammed surfaces to provide the torque. The stator unit (500) comprises a plurality of stator pushers (530-Ua, 530-Va, 530-Wa, 530-Ub, 530-Vb, 530-Wb, 530-Uc, 530-Vc, 530-Wc) configured for movement in a direction radial to a centre of rotation (405) of the body (410) of the rotor unit (400) and for the application of the radial force, whereby movement of the stator pushers induces rotation of the body (410) around the axis of rotation (210).