Infusion Pump Occlusion Detection via Motor Current and Stroke Timing

Solution Overview

Problem

Existing infusion pumps face challenges in accurately detecting occlusions without increasing system complexity or cost, as adding pressure sensors is undesirable for wearable medication delivery pumps.

Innovation Solution

The infusion device incorporates integral occlusion sensing using a pump measurement device to analyze aspirate and dispense strokes, determining occlusions based on predetermined metrics such as stroke duration or current sensing, without the need for additional pressure sensing components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a pressure sensor is added to the infusion pump system for occlusion detection, then occlusion detection accuracy is improved, but system complexity increases

Engineering Contradiction:

Improveocclusion detection accuracyVSAvoidsystem complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The pump system uses its own existing operational parameters (motor current, stroke duration, pump cycle timing) to detect occlusions, rather than requiring external pressure sensors. The control device analyzes how the pump's own performance characteristics change when an occlusion occurs, making the system self-diagnostic.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The patent replaces the mechanical pressure sensing approach with electrical and temporal measurements. Instead of measuring pressure directly with a pressure sensor, the system measures electrical current draw and temporal characteristics of pump strokes, substituting mechanical measurement with electrical and time-based measurements.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If a pressure sensor is added to the infusion pump system for occlusion detection, then occlusion detection accuracy is improved, but manufacturing cost increases

Engineering Contradiction:

Improveocclusion detection accuracyVSAvoidmanufacturing cost

Core Design Contradiction:

Measurement precisionVSEase of manufacture

Solution Approach 1:

The pump motor and control device perform multiple functions: they not only drive the pump mechanism but also serve as sensors for detecting occlusions. The motor current measurements and stroke duration measurements, originally used for basic pump operation control, are repurposed to provide occlusion detection functionality.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system uses its own existing operational parameters (motor current, stroke duration, pump cycle timing) to detect occlusions, rather than requiring external pressure sensors. The control device analyzes how the pump's own performance characteristics change when an occlusion occurs, making the system self-diagnostic.

Inventive Principle:

Principle #25Self-service

3Measurement precision

If a pressure sensor is added to the infusion pump system for occlusion detection, then occlusion detection accuracy is improved, but power consumption increases

Engineering Contradiction:

Improveocclusion detection accuracyVSAvoidpower consumption

Core Design Contradiction:

Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent replaces the mechanical pressure sensing approach with electrical and temporal measurements. Instead of measuring pressure directly with a pressure sensor, the system measures electrical current draw and temporal characteristics of pump strokes, substituting mechanical measurement with electrical and time-based measurements.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The pump system uses its own existing operational parameters (motor current, stroke duration, pump cycle timing) to detect occlusions, rather than requiring external pressure sensors. The control device analyzes how the pump's own performance characteristics change when an occlusion occurs, making the system self-diagnostic.

Inventive Principle:

Principle #25Self-service

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

This solution enables accurate occlusion detection, automatically terminating pump operation and alerting the user, while maintaining system simplicity and cost-effectiveness, thus ensuring reliable medication delivery.

Implementation Method 1

Pump motor current sensing can also be employed to detect occlusion conditions in a pump

Methodology Applied

Scientific EffectElectrical Resistance: Electrical Resistance

Data Source

PatentUS20250090750A1Systems, apparatuses and methods for occlusion detection using pump operation measurement

Publication Date: 2025.03.20 BECTON DICKINSON & CO

AI summary

A technical solution for monitoring operation of a medical delivery device such as an infusion pump for occlusion is provided that employs sensing pump motor current and monitoring motor current with respect to at least one of a dispense stroke and an aspirate stroke in a pump cycle. The solution can be implemented alone or in combination with other occlusion sensing methods that use one or more of pump measurement data such as pump stroke duration (e.g., duration of aspirate stroke or dispense stroke in a rotational metering-type pump or a reciprocating-type pump), end-stop or limit switch activation, and duration difference between aspirate and dispense strokes to detect occlusion.