Robotic Surgery Tool Driver With Torque Sensing in a Compact Carriage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional robotic-assisted surgical systems face challenges with large and difficult-to-manage tool drivers, which hinder efficient manipulation of surgical tools during minimally-invasive procedures, requiring more compact and efficient solutions to reduce surgeon workload and improve surgical precision.
Innovation Solution
A tool driver system for robotic surgery featuring a compact base with a longitudinal track and a sliding tool carriage equipped with linear and rotary axis drive assemblies, including a capacitive load cell and position sensors, to facilitate precise articulation and rotation of surgical tools, and a torque sensor with a torsional spring structure for measuring reaction torque, allowing for modular and scalable configurations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If conventional robotic tool drivers are used, then surgical tools can be manipulated remotely, but the tool drivers become large and difficult to maneuver with robotic arms
Solution Approach 1:
The tool driver is divided into modular components: a base module that couples to the robotic arm, a tool carriage module that slides along a track, and drive assembly modules. This segmentation allows each module to be optimized independently and facilitates easier integration with robotic arms of varying sizes.
Solution Approach 2:
The tool carriage is nested within the base structure, sliding along a longitudinal track that is integrated into the base. The drive assemblies are nested within the tool carriage, with motors and transmission components housed within compact enclosures. This nesting approach minimizes the overall volume while maintaining functionality.
2Volume of moving object
If compact tool driver design is implemented, then maneuverability improves, but precision in articulation and rotation of surgical tools may be compromised
Solution Approach 1:
Traditional mechanical linkages and cable-driven systems are replaced with direct-drive motor assemblies and belt-driven mechanisms. Each degree of freedom (articulation and rotation) is controlled by dedicated motor assemblies with integrated encoders, providing precise control without requiring complex mechanical transmission systems.
Solution Approach 2:
The system uses high-resolution encoder feedback to continuously monitor and adjust motor position and velocity parameters. The control system dynamically adjusts motor commands based on real-time position data, maintaining precision despite the compact physical dimensions of the drive assemblies.
3Manufacturing precision
If multiple sensors and drive assemblies are added for precise control, then tool manipulation precision improves, but device complexity increases
Solution Approach 1:
The tool carriage is designed as a universal platform that can accommodate various surgical tools with different functions. The same drive assemblies and sensor systems are used regardless of which tool is attached, reducing the need for tool-specific mechanisms. The modular design allows the core system to remain simple while adapting to different surgical instruments.
Solution Approach 2:
Multiple sensor functions are integrated into single components where possible. For example, the load cell structure serves both as a mechanical support element and as a sensor mounting platform. The capacitive load cell combines force sensing with structural function, reducing the number of separate components needed.
4Measurement precision
If capacitive load cells and torque sensors are integrated, then measurement precision of axial load and reaction torque improves, but the compact space available for sensor placement is limited
Solution Approach 1:
The load cell and torque sensor are positioned at specific locations where they can measure forces most effectively. The capacitive load cell is placed in the tool carriage where it can measure axial loads during tool manipulation. The torque sensor is integrated into the rotary drive assembly where it can directly measure reaction torque. This strategic placement maximizes measurement precision while minimizing space requirements.
Solution Approach 2:
The torque sensor is nested within the rotary drive assembly, with the sensing elements integrated into the motor housing or coupling structure. The load cell is nested within the tool carriage framework, using the structural members themselves as part of the sensing mechanism. This nesting allows high-precision sensors to be accommodated within the compact tool driver volume.
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 tool driver system enhances the compactness and efficiency of robotic surgical systems, reducing surgeon workload and improving precision by enabling precise articulation and rotation of surgical tools, while maintaining compactness and scalability for various surgical tasks.
Implementation Method 1
The capacitive load cell may include a first conductive plate fixed relative to the guide and a second conductive plate fixed relative to the threaded shaft
Implementation Method 2
a torque sensor with a torsional spring structure for measuring reaction torque
Implementation Method 3
The threaded shaft may, in some variations, be a ball screw and the guide may be or include a ball screw nut engaged with the ball screw
Data Source
AI summary
A tool driver for use in robotic surgery includes a base configured to couple to a distal end of a robotic arm, and a tool carriage slidingly engaged with the base and configured to receive a surgical tool. In one variation, the tool carriage may include a plurality of linear axis drives configured to actuate one or more articulated movements of the surgical tool. In another variation, the tool carriage may include a plurality of rotary axis drives configured to actuate one or more articulated movements of the surgical tool. Various sensors, such as a capacitive load cell for measuring axial load, a position sensor for measuring linear position of the guide based on the rotational positions of gears in a gear transmission, and/or a capacitive torque sensor based on differential capacitance, may be included in the tool driver.