Offset Drive Bar in Surgical Instrument Assembly
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Solution Overview
Problem
The complexity of assembling surgical instruments with multiple functional components, such as bipolar and monopolar features, increases due to spatial and functional constraints, making it challenging to design a single instrument that can efficiently switch between modes without the need for alternating instruments.
Innovation Solution
A surgical instrument with a housing, actuator, shaft, and end effector assembly, featuring a drive assembly with a proximal sleeve, drive bar, and lock washer that allows for the manipulation of jaw members between spaced-apart and approximated positions, enabling both bipolar and monopolar modes of operation, and facilitating the deployment and retraction of the monopolar assembly even when the shaft is bent off-axis.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple functional components are added to a surgical instrument to enable both bipolar and monopolar modes, then the versatility and adaptability of the instrument is improved, but the device complexity and assembly difficulty increase
Solution Approach 1:
The drive bar is positioned offset from the longitudinal axis of the proximal sleeve, creating an eccentric arrangement where the drive bar operates within the interior lumen of the proximal sleeve. This nested configuration allows multiple drive components to occupy overlapping spatial zones without interfering with each other, enabling compact integration of bipolar and monopolar drive mechanisms within a single instrument shaft.
Solution Approach 2:
The patent introduces an eccentric positioning dimension by offsetting the drive bar from the central longitudinal axis. This creates a non-coaxial arrangement that allows independent movement of bipolar and monopolar components along different spatial paths, resolving interference issues while maintaining both functions within the same instrument.
2Adaptability or versatility
If multiple functional components are added to a surgical instrument to enable both bipolar and monopolar modes, then the versatility and adaptability of the instrument is improved, but the ease of manufacture decreases
Solution Approach 1:
The lock washer is pre-configured with an aperture matching the offset position of the drive bar before assembly. This preliminary preparation of the fastening component ensures that the eccentric drive bar can be quickly secured to the proximal sleeve without requiring complex alignment procedures or specialized tooling during the assembly process.
Solution Approach 2:
The proximal sleeve with its interior lumen serves multiple functions: it acts as a structural support element, a guide for the offset drive bar, and a containment structure for the eccentric arrangement. This multi-functional design reduces the number of separate components needed, simplifying both manufacturing and assembly.
3Adaptability or versatility
If a single instrument incorporates both bipolar and monopolar features, then the need for alternating instruments is eliminated, but spatial constraints within the instrument become more challenging
Solution Approach 1:
The offset drive bar is nested within the interior lumen of the proximal sleeve, allowing the bipolar drive mechanism to occupy the central axial space while the monopolar components can be arranged in the annular space between the drive bar and sleeve wall. This nested arrangement maximizes space utilization in the constrained instrument environment.
Solution Approach 2:
By moving the drive bar from the central axis to an offset position, the patent creates additional radial space along the longitudinal axis. This dimensional reconfiguration allows monopolar components to be positioned in previously unavailable spatial zones, effectively increasing the usable internal volume for multiple functional elements.
Data Source
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AI summary
A surgical instrument including a housing, an actuator operably associated with the housing, a shaft extending from the housing, an end effector assembly disposed at an end portion of the shaft, and a drive assembly operably coupling the actuator and the end effector assembly with one another such that actuation of the actuator manipulates the end effector assembly. The drive assembly includes a proximal sleeve defining a longitudinal axis and an interior lumen extending longitudinally therethrough, a drive bar including a proximal portion and a distal portion, and a lock washer configured to engage the proximal portion of the drive bar with the proximal sleeve such that the proximal portion of the drive bar is disposed within the interior lumen of the proximal sleeve and positioned offset relative to the longitudinal axis of the proximal sleeve. Methods of assembling such drive assemblies are also provided.