Segmented Dexterous Manipulator for Retinal Microsurgery
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Solution Overview
Problem
Current retinal microsurgery instruments face limitations due to constrained motion and workspace, particularly in procedures like epiretinal membrane peeling and retinal vein cannulation, where additional degrees of freedom are needed for precise manipulation and control within the eye, leading to suboptimal success rates and safety.
Innovation Solution
Development of dexterous manipulation devices with a diameter of 1 mm or less that can articulate up to 90 degrees or more in a small working space, such as a snake-like device with multiple conjoined units, providing enhanced curvature and range of motion, and incorporating actuation units with motors and pulleys for robotic control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If traditional rigid surgical instruments are used with trocar constraints, then the instrument can be inserted through the sclera, but the instrument motion is coupled with eye movement and workspace is limited to three rotational DOFs and one translational DOF
Solution Approach 1:
The instrument is divided into multiple segments or links that can articulate relative to each other. The distal end of the instrument incorporates additional degrees of freedom through segmented construction, allowing independent motion of each segment while the proximal end maintains the trocar constraint. This enables the distal end to achieve greater workspace and orientation flexibility without violating the remote center-of-motion constraint at the sclerotomy site.
Solution Approach 2:
The instrument transitions from a rigid structure to a dynamic, articulated structure. The distal end incorporates movable joints or articulation mechanisms that allow real-time adjustment of orientation and position. This dynamic capability enables the instrument to adapt to varying surgical requirements, grasp membranes at optimal angles, and control peeling trajectories while maintaining compatibility with the fixed trocar entry point.
2Ease of operation
If straight instruments are used for ERM peeling, then the instrument can be inserted through the trocar, but the surgeon cannot grasp the membrane at the optimum angle or control the peeling trajectory effectively
Solution Approach 1:
The instrument incorporates dynamic articulation at the distal end, allowing the surgeon to adjust the tool orientation in real-time during the procedure. This enables optimal angle adjustment for membrane grasping and peeling trajectory control, transforming a static straight instrument into a dynamically adaptable tool that responds to surgical requirements.
Solution Approach 2:
The instrument adds rotational degrees of freedom at the distal end, transitioning from one-dimensional linear motion to multi-dimensional articulated motion. This allows the tool to operate in additional orientation dimensions, enabling the surgeon to approach the membrane from various angles and control the peeling process in three-dimensional space rather than being constrained to a single linear path.
3Adaptability or versatility
If angled instruments are used to improve approach angle, then more flexibility is provided, but multiple instruments are required and surgical workflow becomes cumbersome
Solution Approach 1:
The instrument is designed as a universal platform that can perform multiple functions through a single device. The articulated distal end can be configured to achieve various approach angles and orientations, replacing the need for multiple specialized angled instruments. The same instrument can adapt to different surgical tasks including membrane grasping, peeling, and potentially other retinal procedures, streamlining the surgical workflow.
Solution Approach 2:
The instrument transitions from fixed angled configurations to dynamic, adjustable articulation. Instead of requiring separate instruments for different angles, a single instrument with movable joints can achieve any required orientation during the procedure. This dynamic adaptability consolidates multiple instrument functions into one versatile tool.
4Volume of moving object
If the distal end of the instrument is made smaller to access confined retinal spaces, then access to small vessels is improved, but the instrument becomes more difficult to control and manipulate
Solution Approach 1:
The instrument is segmented into a larger proximal portion for manipulation and control, and a smaller distal portion for access to confined spaces. The articulation joints connect these segments, allowing the distal end to be miniaturized for vessel access while the proximal end maintains sufficient size for surgeon control. The segmented structure enables independent optimization of each portion's dimensions.
Solution Approach 2:
The articulated connection between segments provides dynamic leverage and control mechanisms. The joints act as mechanical advantage points, allowing the surgeon to control the small distal end with greater ease through the articulated linkage. The dynamic structure amplifies control forces from the proximal end to the distal end, compensating for the reduced size and improved manipulability.
Data Source
AI summary
Dexterous manipulation devices are provided having an end effector enabling large curvature with a diameter of 1 mm or less that can articulate about an axis in a working space of about or less than 4 mm by 4 mm. Preferred devices are robotically actuated and controlled and can be used for a variety of therapeutic and diagnostic applications.