Surgical Cutting Assembly Irrigation Spacer for Shaft Travel Control
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Solution Overview
Problem
Existing surgical instruments face issues with cutting assemblies that are not rigidly coupled, leading to unwanted movement during handling, and suction and irrigation ports that interfere with each other and hinder easy coupling, affecting surgical efficiency.
Innovation Solution
A cutting assembly with a rigidly coupled outer tube and cutting shaft, featuring a seal and retention flange to maintain alignment, and a design that separates suction and irrigation ports to prevent interference, ensuring stable handling and efficient fluid flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If the cutting shaft is allowed to extend fully distal to the hub for improved cutting access, then the cutting capability is enhanced, but irrigation fluid cannot reach the distal tip because the shaft blocks the irrigation path
Solution Approach 1:
The irrigation system is segmented into multiple pathways: an outer hub irrigation path and an inner cutting shaft irrigation path. The cutting shaft itself is divided into sections, with the proximal section receiving irrigation fluid through its own lumen and the distal section receiving fluid through the outer hub path, allowing independent irrigation routes for different segments of the cutting assembly.
Solution Approach 2:
An irrigation adapter is introduced as an intermediary component that couples to the proximal end of the cutting shaft. This adapter provides the irrigation fluid interface and routing mechanism, mediating between the fluid source and the cutting shaft while allowing the shaft to extend distally without blocking the irrigation path.
2Reliability
If the cutting shaft is constrained to prevent over-extension, then irrigation fluid can reach the tip, but the cutting implement cannot reach deep enough for certain procedures
Solution Approach 1:
The cutting shaft is designed with dynamic positioning capability, allowing it to be extended or retracted relative to the outer hub based on procedural needs. The shaft can be positioned at different axial locations while maintaining irrigation fluid delivery through the adapted routing system, providing flexibility rather than a fixed constrained position.
3Length of moving object
If a long cutting shaft is used to reach deep anatomical sites, then procedural capability is improved, but the shaft becomes more flexible and difficult to control
Solution Approach 1:
The cutting shaft is segmented into multiple sections that can articulate relative to each other, allowing the shaft to navigate curved pathways while maintaining control at the proximal end. The segmented construction enables the long shaft to bend and flex to reach deep anatomical sites while the modular design maintains maneuverability and control.
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 solution provides a stable cutting assembly that maintains alignment during handling, allows for improved irrigation, and prevents interference between suction and irrigation ports, enhancing surgical instrument usability and efficiency.
Implementation Method 1
The irrigation spacer (170) defines irrigation passageways (178) configured to be arranged in fluid communication with the handpiece irrigation path (42) of the handpiece (40)
Implementation Method 2
The irrigation spacer (170) is configured to provide a stop of distal axial movement of the cutting shaft (22) and the drive hub (24)
Data Source
Figure 1A
Figure 1B
Figure 2A
AI summary
A cutting assembly (12) for a surgical instrument including a drive assembly (14) having a handpiece (40) defining a handpiece irrigation path (42) comprises an outer hub (34), an outer tube (16) extending from the outer hub (34) and defining a distal tube opening (186), a seal (30) coupled to the outer hub (34), a cutting implement (18) comprising a cutting shaft (22) coaxially disposed within the outer tube (16), and a bur (82). The cutting assembly (12) further comprises a drive hub (24) coupled to a proximal end of the cutting shaft (22) and configured to be removably coupled with the drive assembly (14) for rotating the cutting shaft (22) within the outer tube (16), wherein the cutting shaft (22) and the drive hub (24) are axially movable relative to the outer hub (34). An irrigation spacer (170) is coupled to the outer hub (34) and positioned distal to the drive hub (24), the irrigation spacer (170) defining a bore (174) through which the cutting shaft (22) is rotatably disposed, and further defining irrigation passageways (178) configured to be arranged in fluid communication with the handpiece irrigation path (42) of the handpiece (40). The irrigation spacer (170) is configured to provide a stop of distal axial movement of the cutting shaft (22) and the drive hub (24) for permitting fluid to flow through the irrigation passageways (178).