Peristaltic Pump Feedback Control for Stable Microfluidic CTC Flow

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Solution Overview

Problem

Current microfluidic devices for capturing circulating tumor cells (CTCs) lack effective fluid flow management and control systems, particularly when used over extended periods, leading to statistical variability and inaccurate reflection of tumor cell heterogeneity due to limited blood volume interrogation and dynamic fluid control issues.

Innovation Solution

A device incorporating a peristaltic pump module with a control system that uses a pressure sensor to measure continuous pressure fluctuations, adjusting operating characteristics through a PID feedback control configuration to maintain optimal flow rates and capture CTCs effectively.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If syringe pumps are used to regulate pressure and flow rate through microfluidic systems, then flow control is achieved, but the system size becomes large and dynamic control capability is lacking

Engineering Contradiction:

Improveflow control capabilityVSAvoidsystem size

Core Design Contradiction:

Ease of operationVSVolume of moving object

Solution Approach 1:

The patent replaces traditional mechanical syringe pumps with an electrically controlled peristaltic pump system that uses electrical signals to control fluid flow. This substitution enables dynamic flow rate adjustment through electrical control while maintaining a compact system size suitable for microfluidic applications.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent implements dynamic flow control by enabling real-time adjustment of flow rates through electrical control of the peristaltic pump. The system can dynamically modify operating parameters during operation, allowing adaptation to different experimental conditions and maintaining optimal performance throughout extended interrogation periods.

Inventive Principle:

Principle #15Dynamics

2Ease of operation

If comprehensive flow control instruments are used for microfluidic applications, then dynamic control is achieved, but the system becomes large and expensive

Engineering Contradiction:

Improvedynamic control capabilityVSAvoidsystem cost and size

Core Design Contradiction:

Ease of operationVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical flow control instruments with an electrically controlled peristaltic pump system. This substitution achieves dynamic control capability while significantly reducing system complexity, size, and cost, making the system compatible with rapid, low-cost fabrication approaches.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent achieves dynamic control by enabling electrical adjustment of flow rate parameters rather than requiring complex mechanical instrumentation. This approach allows flexible modification of operating conditions through simple electrical control, reducing both system complexity and cost.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If small blood volumes are interrogated due to patient safety concerns, then patient safety is maintained, but the absolute number of CTCs detected is small leading to statistical variability

Engineering Contradiction:

Improvepatient safetyVSAvoidCTC detection accuracy

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

The patent enables continuous interrogation of blood over extended periods through stable, long-duration operation of the microfluidic system. This continuous operation allows accumulation of data from larger total blood volumes while maintaining patient safety, thereby increasing the number of CTCs detected and reducing statistical variability.

Inventive Principle:

Principle #20Continuity of useful action

Solution Approach 2:

The patent uses dynamic flow control to optimize blood processing rates over time, enabling extended interrogation periods with adjusted flow parameters. This dynamic adjustment allows the system to process larger cumulative blood volumes while maintaining patient safety and maximizing CTC detection accuracy.

Inventive Principle:

Principle #15Dynamics

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

Enables continuous interrogation of larger blood volumes over extended periods, enhancing the number of CTCs available for enumeration and molecular phenotyping, providing more accurate reflection of tumor cell heterogeneity.

Implementation Method 1

Microfluidic flow control using direct-current peristaltic pump

Methodology Applied

Scientific EffectPeristalsis: Peristalsis

Implementation Method 2

a pressure sensor to measure continuous pressure fluctuations of the peristaltic pump module

Methodology Applied

Scientific EffectPressure measurement:

Implementation Method 3

a feedback control configuration to adjust the operating characteristics of the peristaltic pump module in response to the measured continuous pressure fluctuations

Methodology Applied

Scientific EffectFeedback control: Feedback

Data Source

PatentUS12576194B2Microfluidic flow control using direct-current peristaltic pump

Publication Date: 2026.03.17 THE RGT UNIV OF MICHIGAN

AI summary

A peristaltic pump-based apparatus for capturing circulating tumor cells (CTCs) from blood is provided that includes a feedback control architecture that uses models of pump operation and measures of internal pressure fluctuations of the pump (e.g., in the form time-varying and/or position-dependent pressure oscillation data) to adjust pump operating characteristics that smooth pump operation, thereby improving viscosity and consistency of fluid flowing through the pump to a connected microfluidic capture device.