Capacitive Skin-Sensing Injection Device for Safe Needle Release
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing injection devices lack sufficient security and safety features to prevent accidental medication expulsion and user injury, particularly when placed on hard surfaces or when handling the device.
Innovation Solution
Incorporating a capacitive proximity sensor that detects human skin contact and prevents needle deployment unless the device is properly placed on a large, naked body area, combined with a mechanism to retract the needle for safe handling and use.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a capacitive proximity sensor is used to detect skin contact, then safety against accidental needle deployment is improved, but device complexity increases
Solution Approach 1:
The patent replaces mechanical safety switches or pressure sensors with a capacitive proximity sensor that detects skin contact through electrical field changes. This electronic substitution provides more reliable and nuanced detection of actual skin contact versus hard surfaces, improving safety while using standard electronic components to manage complexity.
Solution Approach 2:
The capacitive sensor acts as an intermediary between the user's skin and the needle deployment mechanism. It provides an intermediate detection layer that senses the dielectric properties of skin contact before triggering the injection sequence, preventing direct accidental activation while maintaining a relatively simple overall device architecture.
2Reliability
If the sensor is set to detect only large naked body areas, then accidental medication expulsion is reduced, but ease of operation decreases
Solution Approach 1:
The patent adjusts the capacitive sensor's detection parameters (sensitivity threshold, capacitance change magnitude) to specifically recognize the dielectric properties and surface area characteristics of human skin. By tuning these parameters, the system distinguishes between accidental contact with small objects and intentional placement on the body, improving safety without requiring complex user interactions.
Solution Approach 2:
The sensor system automatically determines whether proper skin contact has been made based on its own measurements of capacitance change and contact area. This self-service detection eliminates the need for additional user confirmation steps or complex operational procedures, maintaining ease of use while ensuring safety through intelligent parameter-based detection.
3Reliability
If the needle mechanism is controlled by the sensor, then user injury from accidental piercing is prevented, but device complexity increases
Solution Approach 1:
The patent implements a feedback control system where the capacitive sensor continuously monitors skin contact status and provides real-time feedback to the needle deployment mechanism. The control unit processes sensor signals and adjusts needle extension accordingly, creating a closed-loop safety system that prevents accidental piercing while using standard feedback control architecture to manage complexity.
Solution Approach 2:
The system performs preliminary detection of skin contact through the capacitive sensor before allowing needle deployment. This preliminary action verifies proper placement on the body surface before the needle mechanism becomes active, preventing accidental injury during handling while using a simple two-stage activation sequence that maintains device simplicity.
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
Enhances user safety by ensuring accurate skin contact detection and preventing accidental needle deployment, reducing risks of medication expulsion and user injury.
Implementation Method 1
comprising a capacitive proximity sensor for detecting proximity or contact of human skin to/with said surface
Data Source
Figure 1~2
Figure 3~4
AI summary
An injection device for injecting medication to a patient, comprising a surface (5) having a through hole (3) for passage of a needle and a capacitive proximity sensor (12, 13, 30) for detecting proximity or contact of human skin to/with said surface (5), is characterised in that the capacitive proximity sensor comprises a first electrode (12), a second electrode (13) defining a capacitance with the first electrode (12) and means (30) for detecting a change in said capacitance due to the proximity of human skin to the sensor, and is further characterised by comprising a compensation electrode (44) for limiting the electric field generated by the first and second electrodes (40, 41) to a determined area.