Memory Metal Split-Shaped Needle for Deep-Seated Tumor Puncture
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Solution Overview
Problem
Current photodynamic therapy methods are ineffective for treating deep-seated tumors due to light absorption in the body, requiring thicker needles with larger diameters for optical fibers, which cause trauma and damage during puncture.
Innovation Solution
A memory metal optical fiber puncture needle tubing with a split-shaped needle made of memory metal that changes shape in response to temperature, allowing for a thinner diameter during insertion and expanding to expose the optical fiber for light emission at the treatment site, combined with a spiral metal casing and vibration motor for easier navigation and reduced resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the optical fiber is wrapped by a hard metal material to overcome resistance during puncturing, then the puncturing capability is improved, but the needle tubing becomes thicker and causes larger trauma and damage to normal vascular tissue
Solution Approach 1:
The needle tubing employs a shape-memory metal outer layer that can dynamically change its shape and properties in response to temperature changes. During puncturing, the metal is heated to maintain a rigid needle-like shape for effective puncture. After puncturing, the metal cools and transforms into a flexible tubing shape that conforms to the vessel wall, minimizing trauma. This dynamic transformation resolves the contradiction between needing strength for puncturing and causing minimal damage during insertion.
Solution Approach 2:
The invention utilizes temperature as a controllable parameter to change the physical properties of the shape-memory metal. By heating the metal to a specific temperature range, it transitions from a flexible state to a rigid needle state, enabling effective puncturing. After the puncturing action is completed, the temperature is reduced, causing the metal to transform back to a flexible state that minimizes damage to the vessel wall. This parameter-based transformation allows the same material to provide both puncturing strength and tissue compatibility.
2Strength
If a large pressure is applied to perform puncturing with a thick needle, then the puncturing is achieved, but it causes larger trauma, damage to normal vascular tissue, and bleeding
Solution Approach 1:
The shape-memory metal needle tubing dynamically adjusts its mechanical properties during the puncturing process. The needle is heated to become rigid, allowing it to penetrate with minimal force required. Once punctured, the needle is cooled and transforms into a flexible tubing that gently expands within the vessel lumen rather than forcing its way through, significantly reducing trauma and bleeding compared to traditional rigid needles that require continuous high pressure.
Solution Approach 2:
The invention exploits the phase transition of shape-memory metal between austenite (rigid) and martensite (flexible) phases through temperature control. The metal is heated to induce the austenite phase for rigid needle formation during puncturing. After puncture, cooling induces the martensite phase, transforming the needle into a flexible tubing that adapts to the vessel wall without requiring large expansion forces, thereby minimizing damage and bleeding.
3Illumination intensity
If the tip of the needle has a hole with sufficient size to allow light to pass out, then light transmission is improved, but the diameter of the needle increases
Solution Approach 1:
The optical fiber is embedded within the shape-memory metal structure, which dynamically changes from a closed needle shape during insertion to an opened tubing shape after puncturing. During the insertion phase, the metal maintains a compact needle shape with minimal diameter. After puncturing and cooling, the metal expands into a flexible tubing that surrounds the optical fiber, providing adequate space for light transmission without requiring a larger initial needle diameter. This dynamic structural transformation resolves the contradiction between light transmission requirements and needle size.
4Strength
If a thick needle tubing is used to protect the optical fiber during puncturing, then the protection is improved, but the trauma and resistance during puncturing increases
Solution Approach 1:
The shape-memory metal provides dynamic protection for the optical fiber. During puncturing, the metal is heated and maintains a rigid needle shape that protects the optical fiber while having minimal diameter and causing minimal trauma. After puncturing, the metal cools and transforms into a flexible tubing that continues to protect the optical fiber but now conforms to the vessel wall, reducing trauma. This dynamic transformation allows adequate fiber protection without the need for a consistently thick needle structure throughout the procedure.
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 efficient light emission and therapeutic effect while minimizing trauma, allowing the needle to smoothly pass through long blood vessels and effectively treat deep-seated tumors with reduced light and photosensitizer waste.
Implementation Method 1
the periphery of the tapered head is wrapped with a split-shaped needle made of memory metal; when the temperature is T0, each of tapered petals in the split-shaped needle made of memory metal is closed; when the temperature is T1, each of tapered petals in the split-shaped needle made of memory metal is opened
Implementation Method 2
the head portion comprises a cylindrical head and a tapered head having a tapered diameter formed by a taper method; the tapered head of the optical fiber is exposed to enable light to direct irradiate onto the tumor
Data Source
AI summary
A memory metal optical fiber puncture needle tubing includes an optical fiber, a body tube, a metal casing and a split-shaped needle. The optical fiber has a body portion and a head portion. The head portion has a cylindrical head portion and a tapered head portion. The body tube surrounds the body portion. The metal casing is wrapped around the cylindrical head portion. The split-shaped needle is made of memory metal surrounding a periphery of the tapered head portion. The split-shaped needle has a plurality of tapered petals. When a temperature of the split-shaped needle is T0, the tapered petals are in a closed state such that the split-shaped needle is conical. When the temperature of the split-shaped needle is T1, the tapered petals are in an opened state such that the tapered head portion of the optical fiber is exposed.