Robotic Surgical End Effector Assembly for Reliable Jaw Pivoting
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Solution Overview
Problem
Existing robotic surgical instruments lack efficient and reliable mechanisms for articulating end effectors that enable precise tissue grasping and cutting, particularly in robotic surgical systems where the console and robotic arm are reused after sterilization, necessitating robust and durable designs.
Innovation Solution
An end effector assembly with a distal segment and jaw members featuring a cam bar and pivot pin mechanism that allows for pivoting between open and closed states, enabling precise tissue grasping and cutting, while being durable for repeated use.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If a reusable end effector assembly is used in robotic surgical instruments, then the console and robotic arm can be protected by sterile barriers and wiped clean for repeated use, but the mechanism must maintain reliability and precision after sterilization
Solution Approach 1:
The end effector assembly is divided into separable components including a distal segment with jaw members, a cam bar, and pivot pins. This segmentation allows the assembly to be disassembled for sterilization while maintaining functional integrity when reassembled, resolving the contradiction between reusability and post-sterilization reliability.
Solution Approach 2:
The cam bar and cam slot mechanism are designed with built-in alignment features and tolerance compensation that ensure proper assembly and function even after sterilization processes. The pivot pins and retaining features provide pre-established positioning that maintains reliability without requiring complex assembly procedures post-sterilization.
2Ease of operation
If the jaw members are designed to pivot between open and closed states for tissue grasping, then precise tissue manipulation is enabled, but the mechanism complexity increases
Solution Approach 1:
The jaw members are designed with pivot joints that enable dynamic movement between open and closed states. The cam bar mechanism provides controlled pivoting motion through cam slots, allowing the jaw to transition smoothly between positions for tissue grasping while maintaining operational simplicity through mechanical advantage.
Solution Approach 2:
The cam bar and cam slot configuration enables the jaw members to self-align and self-lock in their pivoting motion. The geometry of the cam slots provides inherent guidance and positioning, eliminating the need for additional actuators or complex control systems to maintain the pivoting function.
3Ease of operation
If the proximal flange portions are pinned to the distal segment via openings, then the jaw members can pivot relative to the distal segment, but the manufacturing precision requirements increase
Solution Approach 1:
The openings in the distal segment are positioned asymmetrically relative to the cam slots and pivot pin arrangement. This asymmetric design provides self-alignment during assembly, where the cam bar and pivot pin naturally guide the openings into their correct positions, reducing the precision requirements for manufacturing while maintaining the pivoting function.
Solution Approach 2:
The cam bar and pivot pin are designed with preliminary positioning features that establish the correct alignment of the openings before final assembly. The cam slot geometry and pivot pin arrangement provide pre-established reference points that ensure proper positioning, allowing for tolerance in manufacturing while maintaining functional precision.
Data Source
AI summary
An end effector assembly of a robotic surgical instrument includes a distal segment and first and second jaw members supported by the distal segment. The distal segment defines an elongate slot therein. The first jaw member has a proximal flange portion received in the elongate slot of the distal segment, and the second jaw member has a proximal flange portion received in the distal segment. The proximal flange portions of each of the first and second jaw member are pinned to the distal segment.