Drug Delivery Pusher-Switch Layout for Accurate End Detection

Solution Overview

Problem

Existing drug solution administration apparatuses face issues with inaccurate detection of administration completion due to decreased switch recovery force when the pusher and switch remain in contact during storage, leading to erroneous notifications.

Innovation Solution

The apparatus is designed with a pusher and switch configuration that maintains non-contact before use, incorporating an operation test to ensure the switch is turned on before starting administration, and uses a recess to prevent contact failure, ensuring accurate detection of administration completion based on the state of contact between the pusher and switch.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the pusher and switch are constantly in contact during storage, then the switch is ready for immediate operation, but the recovering force of the switch decreases leading to detection errors

Engineering Contradiction:

Improvereadiness for operationVSAvoidswitch detection accuracy

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The control unit performs a preliminary operation test before actual drug solution administration to verify switch functionality. The pusher is moved forward by a predetermined distance to check if the switch turns on properly, ensuring the switch recovering force is sufficient before clinical use

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The constant contact between pusher and switch during storage is eliminated by separating their positions. The switch is positioned such that contact only occurs during operation, not during storage, preventing degradation of switch recovering force

Inventive Principle:

Principle #2Taking out (Extraction)

2Reliability

If the switch recovering force decreases, then the switch fails to turn off properly, but this leads to erroneous recognition of administration completion

Engineering Contradiction:

Improveswitch state stabilityVSAvoidadministration completion detection accuracy

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

The control unit performs a preliminary operation test before actual drug solution administration to verify switch functionality. The pusher is moved forward by a predetermined distance to check if the switch turns on properly, ensuring the switch recovering force is sufficient before clinical use

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The control unit continuously monitors switch state and provides feedback. When the pusher moves forward by a predetermined distance, the control unit checks if the switch turns on; when administration completes, it verifies the switch turns off, enabling accurate detection of administration completion status

Inventive Principle:

Principle #23Feedback

3Reliability

If the pusher is disposed non-contact with the switch before use, then the switch recovering force is maintained, but an operation test is required to ensure proper functionality

Engineering Contradiction:

Improveswitch recovering forceVSAvoidoperation test procedure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The control unit performs a preliminary operation test before actual drug solution administration to verify switch functionality. The pusher is moved forward by a predetermined distance to check if the switch turns on properly, ensuring the switch recovering force is sufficient before clinical use

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system performs self-verification through automated operation tests. The control unit automatically moves the pusher to test positions, checks switch states, and determines whether the device is suitable for use, eliminating the need for manual testing

Inventive Principle:

Principle #25Self-service

Data Source

PatentEP3925646B1Liquid medicine administration device and liquid medicine administration set

Publication Date: 2026.04.15 TERUMO KK

Figure 1~2
Figure 3
Figure 4~5

AI summary

To provide a drug solution administration apparatus and a drug solution administration set in which the control unit can accurately detect completion of administration of a drug solution on the basis of the state of contact between the pusher and the switch. Before a drug solution administration apparatus 100 is in use, a pusher 130 included in the drug solution administration apparatus 100 is disposed in a housing 120 in the state where the pusher is non-contact with a switch 160, and a control unit 170 is configured to, prior to start of administration of a drug solution, conduct an operation test of checking whether the switch is turned on when the pusher is moved forward by a predetermined distance L1 and, after it is confirmed that the switch is turned on in the operation test, to perform an administration start operation for administering the drug solution.