Surgical Probe Deflection via Shape Memory Alloy and Free-Floating Interface
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Solution Overview
Problem
Current surgical tools face challenges in accessing hard-to-reach body parts without invasive procedures, and existing deflection systems are limited in their ability to provide precise orientation and omnidirectional movement, especially in small anatomical spaces.
Innovation Solution
A surgical system featuring a deflectable probe with a probe body and tip, guided by a control system that includes a free-floating user interface, motion sensors, and actuators, allowing for precise omnidirectional deflection and movement within a 360-degree range, enabling access to target anatomical locations through vascular or non-vascular pathways.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If conventional surgical tooling is used to access hard-to-reach body parts, then direct access can be achieved, but the procedure becomes highly invasive and risky
Solution Approach 1:
The surgical tool is divided into multiple segments including a proximal portion, a distal portion, and an intermediate section with articulation joints. This segmentation allows the tool to navigate complex anatomical pathways through sequential bending at each joint, enabling access to hard-to-reach areas without requiring long straight incisions or highly invasive procedures
Solution Approach 2:
The tool incorporates multi-planar deflection capabilities with articulation joints that enable bending in multiple directions (radial, lateral, and longitudinal planes). This multi-dimensional movement allows the distal tip to reach target locations that would be inaccessible through simple linear insertion, reducing the need for invasive surgical approaches
2Adaptability or versatility
If pull wire systems are used for multi-plane deflection, then vessel navigation capability is improved, but the device size increases and limits application to robotic systems and large medical devices
Solution Approach 1:
The patent replaces traditional mechanical pull wire systems with shape memory alloy (SMA) actuators that use thermal-mechanical coupling for deflection. SMA wires can be actuated electrically to produce bending moments through controlled heating and cooling cycles, eliminating the need for complex mechanical wire systems while achieving multi-plane deflection in a more compact form factor
Solution Approach 2:
The deflection mechanism utilizes changes in temperature as a control parameter to activate shape memory alloy wires. By applying electrical heating current to SMA wires, the material undergoes phase transformation and contracts, producing bending moments. This parameter-based control (temperature/electrical current) replaces mechanical wire tension systems, reducing device complexity and size
3Ease of operation
If rotation along central axis is used to steer fixed deflection planes, then directional control is achieved, but resistance from contacted tissues must be overcome
Solution Approach 1:
The tool features dynamic articulation joints that allow real-time adjustment of deflection planes and angles. Rather than rotating a fixed deflection plane against tissue resistance, the articulation joints enable the tool to adapt its orientation dynamically, bending sequentially at multiple joints to navigate around obstacles and reach targets with minimal force requirement
Solution Approach 2:
The tool is divided into multiple articulated segments that can bend independently at each joint. This segmentation allows the tool to navigate complex pathways by sequential bending rather than requiring high force to rotate a long rigid shaft against tissue resistance, reducing the force needed while maintaining directional control
4Ease of manufacture
If Nitinol based materials are used for deflection, then pull wire replacement is achieved, but high temperature output and other factors make the system suboptimal
Solution Approach 1:
The patent utilizes the temperature-dependent phase transformation properties of shape memory alloys. By applying controlled electrical heating current, the SMA wires undergo austenite-martensite phase transitions, producing controlled contraction and bending moments. The temperature is precisely controlled to achieve deflection without excessive heat generation, optimizing the balance between actuation effectiveness and thermal safety
Solution Approach 2:
The patent replaces mechanical pull wire systems with electrically actuated shape memory alloy wires. The SMA wires respond to electrical current by undergoing phase transformation and contracting, producing bending moments without requiring mechanical wire tension systems. This substitution reduces device complexity while controlling temperature output through electrical parameter management
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
Enables minimally invasive surgical procedures with precise control and access to small, hard-to-reach areas, reducing tissue damage and improving surgical precision and safety by allowing the probe to deflect and maneuver within tight anatomical spaces.
Implementation Method 1
The deflectable probe can include a plurality of shape memory alloy wires spaced from a central axis of the probe in a respective direction, with each wire configured to contract in response to application of a respective amount of current
Implementation Method 2
The processor, in response to the motion signals, can apply deflection signals to at least one of the actuators that causes the at least one of the actuators to urge at least a portion of at least one of the guide arms to move
Data Source
AI summary
A surgical system can include a surgical probe having a deflectable tip, and a plurality of guide arms that are movable so as to cause the tip to deflect. Thus, the surgical probe can be steered toward a target anatomical location. The surgical system can further include a control system that includes a free floating user interface, and a motion sensor that detects motion of the user interface. The control system is configured to cause the probe tip to deflect in response to the detected motion of the user interface.