Segmented Surgical Instrument with Nested Control Rods
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional minimally invasive and robotic surgical techniques often result in permanent scars due to the need for incisions that are too large, which can slow down recovery and cause pain, despite using smaller incisions than traditional open surgery.
Innovation Solution
A surgical instrument with a control portion and a tool portion, where the control portion includes multiple tubular shafts with diameters less than or equal to 2.5 mm, allowing for insertion through small incisions without scarring, and a tool portion with collapsible mandrels and pulleys for articulation, enabling a range of movements while minimizing incision size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If conventional minimally invasive surgical techniques are used, then incision size is reduced compared to open surgery, but permanent scars are still created due to incisions being too large
Solution Approach 1:
The surgical system divides the instrument into multiple separate shafts (e.g., three 2.5 mm shafts) that can be inserted through individual small incisions. Each shaft is independently controllable, allowing the surgeon to perform complex maneuvers through multiple tiny puncture sites rather than requiring a single larger incision, thereby eliminating visible scarring while maintaining surgical capability
Solution Approach 2:
The patent employs nested structures where collapsible mandrels are inserted within the tubular shafts, and tool cables are routed through the mandrels. This nested arrangement allows multiple functional elements to be contained within the small 2.5 mm shaft diameter, enabling complex surgical tools to be delivered through minimally invasive incisions without increasing incision size
2Object-affected harmful factors
If smaller incisions are used to reduce scarring, then scarless surgery is achieved, but the instrument requires high rigidity to maintain functionality
Solution Approach 1:
The shafts are engineered with non-circular cross-sections (e.g., triangular, rectangular, or other polygonal shapes) that provide enhanced rigidity and torsional resistance compared to circular shafts of the same diameter. This local geometric optimization allows the 2.5 mm shafts to maintain sufficient structural strength and stability for surgical manipulation without requiring larger diameters that would create visible scars
Solution Approach 2:
The surgical instrument employs composite construction with multiple materials having different mechanical properties. The shafts combine materials with high strength-to-density ratios, while the collapsible mandrels use materials that can transition between rigid and flexible states. This composite approach enables the instrument to achieve the necessary rigidity for surgical precision while maintaining compatibility with small incision dimensions
3Adaptability or versatility
If multiple control rods and tool cables are used to provide range of movement, then articulation capability is improved, but device complexity increases
Solution Approach 1:
The control system is segmented into multiple independent control rods (e.g., three control rods) that can be manipulated separately. Each control rod corresponds to a specific degree of freedom or surgical function, allowing independent control of different instrument components. This segmentation enables complex articulation and dexterity comparable to open surgery while maintaining a relatively simple overall structure where each control element has a dedicated function
Solution Approach 2:
The patent implements a nested cable-pulley system where tool cables are routed through collapsible mandrels and connected to pulleys at the distal end. The cables are nested within the mandrel structure, and the pulleys are integrated into the tool assembly. This nested arrangement allows multiple cables to be managed within the constrained space of the small shafts while maintaining full articulation capability, reducing the complexity of cable routing and component arrangement
Data Source
AI summary
A surgical instrument and methods of use. The surgical instrument can include a control portion having a plurality of tubular shaft portions and a plurality of control rods. Each of the plurality of tubular shaft portions can have a diameter of less than or equal to about 2.5 mm. At least one of the plurality of control rods can extend through each of the plurality of shaft portions. The surgical instrument can also include a tool portion having a plurality of tool rods and a plurality of tool cables. Each of the plurality of tool cables can be connected to one of the plurality of control rods. Further, each of the tool rods can be removably connected to one of the plurality of control rods.