Needle Biosensor Direct Skin Insertion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Implantable sensors face challenges such as tissue reaction to foreign bodies, barrier layer formation, high molecular flux causing disturbance, and complex manufacturing processes, which affect biocompatibility and accuracy in monitoring molecules like glucose and oxygen in subcutaneous tissue.
Innovation Solution
A subcutaneously implanted needle-shaped sensor assembly with minimal diameter and large sensing surface area, featuring perpendicular needle electrodes that can be directly inserted into the skin without a catheter, utilizing a biosensing layer with enzyme and biocompatible polymers to minimize tissue disturbance and maximize sensitivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional implanted sensors are used with catheters or cannula, then the sensor can be implanted, but the extra damage to tissue by assisting devices affects sensor performance and biocompatibility
Solution Approach 1:
The patent removes the catheter/cannula component from the implantation system, allowing the sensor to be directly inserted into tissue without auxiliary devices. This extraction of the harmful intermediary component eliminates the additional tissue damage caused by catheters while maintaining the sensor's ability to be implanted and function.
Solution Approach 2:
Instead of using a catheter to deliver the sensor to the tissue (conventional approach), the patent inverts the approach by making the sensor itself the insertion instrument. The needle-shaped sensor is directly inserted into the tissue, reversing the traditional sequence where the sensor is delivered through a separate catheter system.
2Object-affected harmful factors
If sensor active area is made very small to reduce tissue disturbance, then molecular flux is reduced, but sensing sensitivity decreases
Solution Approach 1:
The patent transitions from a planar sensor geometry to a three-dimensional needle structure. By extending the sensor area along the length of the needle (adding a dimensional aspect), the total sensing area increases while the cross-sectional footprint remains minimal, allowing reduced tissue disturbance while maintaining sensitivity.
Solution Approach 2:
The patent employs thin film structures for the sensor electrodes and biocompatible coatings on the needle surface. These thin films provide sufficient sensing area through their extended surface while maintaining a minimal physical presence in the tissue, reducing disturbance while enabling detection.
3Object-affected harmful factors
If needle diameter is minimized for direct insertion, then tissue damage is reduced, but manufacturing precision requirements increase
Solution Approach 1:
The patent divides the needle sensor into separate functional segments (electrodes, coatings, structural layers) that can be manufactured independently and then assembled. This segmentation allows each component to be fabricated with appropriate precision for its specific function, making the overall minimal-diameter design manufacturable through modular assembly rather than requiring the entire structure to be precision-fabricated as a single piece.
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 solution reduces tissue damage, ensures high sensitivity and accuracy in monitoring physiological molecules, and simplifies manufacturing, enabling continuous and reliable monitoring of glucose and oxygen levels.
Implementation Method 1
Apparatus with electrochemical sensors obtain such properties by measuring electrical signals generated from electrochemical redox reactions of the molecules
Implementation Method 2
utilizing a biosensing layer with enzyme and biocompatible polymers to minimize tissue disturbance and maximize sensitivity
Implementation Method 3
The sensor electrodes can be directly inserted into the skin, without the need of a catheter
Data Source
AI summary
Electrochemical biosensors consisting of two or more needle-shaped electrodes for monitoring of molecules such as glucose in the subcutaneous tissue are provided. The two electrodes are parallel to each other, and are fixed perpendicularly to the planar side of a sensor base which provides skin fixation and electric connection. The needle electrodes are made of rigid conducting materials, capable of inserting into the skin without the need of catheters. One electrode is the sensing electrode and the other, the reference electrode. A compound sensing membrane is attached onto the sensing electrode surface to detect analyzed molecules.