Inline Needle Catheter Structure for Kink-Resistant Hemodialysis Access
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Solution Overview
Problem
Current hemodialysis needles cause frequent fistula/graft damage due to needle migration or movement, leading to blood leakage and hematoma, and existing combined needle and catheter devices suffer from kinking and collapse during high blood flow, necessitating improved vascular access solutions.
Innovation Solution
A vascular access catheter with an inline needle that slides within a slidable catheter, ensuring the needle tip is protected within the catheter during use, preventing damage and maintaining blood flow by keeping the needle intact, and featuring retention mechanisms to secure the catheter position relative to the needle.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a sharp needle is used for hemodialysis access, then blood flow rate is improved, but fistula/graft damage and needle migration occur
Solution Approach 1:
The needle is nested within the catheter body, allowing the sharp needle to be protected during insertion while remaining exposed at the tip for blood flow. The catheter body acts as a protective sheath that can be retracted or positioned to expose/cover the needle as needed, preventing needle migration damage while maintaining blood flow capability.
Solution Approach 2:
The catheter is pre-positioned over the needle before insertion, establishing a protective relationship in advance. The catheter body is initially in a retracted position to allow needle insertion, then advanced to cover and secure the needle, preventing subsequent migration and damage to the fistula/graft.
2Productivity
If the needle is exposed for blood flow, then dialysis efficiency is improved, but needle stick injuries and infiltration risk increase
Solution Approach 1:
The catheter body is designed to be dynamically repositionable relative to the needle, allowing it to transition between covering and exposing the needle tip. This dynamic positioning enables the system to switch between safety mode (needle covered) and operational mode (needle exposed for blood flow), addressing both safety and efficiency requirements.
Solution Approach 2:
The catheter body serves as an intermediary between the sharp needle and the external environment, providing a protective barrier when the needle is not in use. This intermediary structure allows the needle to remain in place for continuous blood flow while being shielded from causing injuries during patient movement or device handling.
3Ease of operation
If the catheter is thin-walled for flexibility, then ease of insertion is improved, but kinking and collapse during high blood flow occur
Solution Approach 1:
The device merges the thin-walled catheter with the rigid needle structure, creating a hybrid system where the needle provides structural support during insertion and blood flow, while the catheter provides flexibility and comfort. The combined structure maintains flexibility for easy insertion while the needle reinforcement prevents kinking and collapse during high blood flow rates.
Data Source
AI summary
Exemplary embodiments described herein are directed to a vascular access catheter device with an inline needle, the device having a needle portion that is linearly displaceable relative to a catheter portion, and vice versa, and to methods of performing blood transfer procedures using said device. Retraction of the needle portion relative to the catheter portion allows the catheter of the catheter portion to cover the needle tip during a blood transfer procedure, thereby preventing needle damage to a fistula/graft or peripheral vessel of a patient, as well as possible needle stick injuries to health care workers during removal/disposal of a used device. Because the needle still remains largely within the catheter after retraction, there is no risk of catheter collapse, kinking, etc., during use, which could compromise blood flow during a hemodialysis or other vascular access procedure.