Flexible Endoscope Shaft Bending With Base-Mounted SMA Actuation
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Solution Overview
Problem
Existing endoscopic devices face limitations in angular maneuverability, requiring two-handed operation, manual actuation, and are bulky, costly, and require extensive sterilization, which affects their functionality and lifespan.
Innovation Solution
An endoscopic device with a flexible shaft featuring a bending section actuated by shape memory alloy (SMA) coils located in the base, allowing controlled bending up to 180° in multiple directions, and a disposable sheath to maintain sterility, reducing the need for extensive sterilization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If manual actuation mechanism with angulation wires is used, then bending capability is achieved, but device complexity and bulk increase
Solution Approach 1:
The patent replaces the manual mechanical actuation system (angulation wires and levers) with a shape memory alloy actuator that uses thermal-mechanical coupling. The SMA element transforms thermal energy from electrical current into mechanical bending motion, eliminating the need for complex mechanical wire-tensioning mechanisms while achieving the same bending capability.
Solution Approach 2:
The invention changes the actuation parameter from manual mechanical force application to electrical current-induced thermal change. By passing current through the SMA actuator, the material undergoes phase transformation that directly produces bending motion, simplifying the actuation interface and reducing mechanical complexity.
2Ease of operation
If shape memory alloy coils are placed in the insertion portion, then bending control is improved, but device diameter increases
Solution Approach 1:
The patent relocates the SMA actuator from the radial dimension (within the insertion portion) to the longitudinal dimension (in the base). This dimensional relocation allows the actuator to extend along the shaft axis, utilizing the longer available space in the base rather than constraining the coil diameter in the narrower insertion portion, thereby maintaining small device diameter while preserving bending control capability.
Solution Approach 2:
The invention segments the device into distinct functional zones: the insertion portion remains slender and minimally invasive, while the base houses the bulkier actuation components. This segmentation allows the SMA actuator to be positioned in the base where space is abundant, keeping the insertion portion diameter small for patient comfort and ease of insertion.
3Ease of manufacture
If reusable endoscopic device is used, then cost is reduced, but sterilization requirement increases procedural complexity
Solution Approach 1:
The patent extracts the sterilization requirement from the reusable device components by introducing a disposable sheath that contacts the patient. This sheath is discarded after single use, eliminating the need to sterilize the expensive reusable components (shaft, actuator, electronics), thereby reducing procedural complexity while maintaining cost-effectiveness through device reusability.
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 device provides enhanced maneuverability, reduces size and cost, allows procedures without general anesthesia, and is reusable, increasing accessibility and reducing procedural costs.
Implementation Method 1
the actuation arrangement includes at least one actuator which is at least partially made from a shape memory alloy, and which is configured to displace the bending section of the shaft when electric current is passed therethrough
Data Source
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AI summary
THIS invention relates to an endoscopic device, and more particularly but not exclusively to an endoscopic device suitable for use in diagnostic and/or surgical procedures. The endoscopic device includes a base and a shaft extending from the base, wherein the shaft is at least partially flexible and includes a bending section that is selectively displaceable between a straight configuration and a bent configuration. The device also includes an actuation arrangement for selectively displacing the bending section between the straight and bent positions, wherein the actuation arrangement includes at least one actuator which is at least partially made from a shape memory alloy, and which is configured to displace the bending section of the shaft when electric current is passed therethrough, characterized in that the actuator is located inside the base of the device.