Syringe Pump Cam Grasper Mitigates Lead Screw Runout

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Solution Overview

Problem

Syringe pumps in medical applications face challenges in efficiently delivering precise amounts of medications over extended periods, with existing systems lacking flexibility in accommodating different syringe sizes and types, and often experiencing issues with lead screw runout and occlusion detection.

Innovation Solution

A syringe pump design featuring a modular architecture that allows interchangeability between syringe and peristaltic pumps, incorporating a sliding block assembly with a cam mechanism for engaging and disengaging with a lead screw, and redundant sensors for occlusion detection and fluid pressure monitoring, along with a method to mitigate lead screw runout using rotary and linear position sensors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a syringe pump uses a lead screw mechanism for precise plunger actuation, then delivery precision is improved, but lead screw runout causes positioning errors

Engineering Contradiction:

Improvedelivery precisionVSAvoidpositioning accuracy

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The patent employs feedback control by using a linear encoder to continuously monitor the actual position of the plunger and comparing it with the commanded position. The controller adjusts the motor output based on the position error signal, compensating for lead screw runout and achieving accurate delivery despite mechanical imperfections.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent replaces pure mechanical positioning with an electro-mechanical system. Instead of relying solely on the lead screw mechanical transmission, the system uses a motor driven by electronic control with real-time position feedback from a linear encoder, substituting mechanical precision requirements with electronic control and sensing.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If a syringe pump is designed with fixed architecture for specific syringe types, then delivery precision is improved, but adaptability to different syringe sizes is reduced

Engineering Contradiction:

Improvedelivery precisionVSAvoidadaptability to different syringe sizes

Core Design Contradiction:

Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent designs the syringe pump with universal mounting mechanisms and adjustable components that can accommodate multiple syringe sizes and types. The pump head and plunger assembly are configured to work with various syringe dimensions through adjustable clamping mechanisms and interchangeable components, allowing a single device to perform multiple functions.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent incorporates dynamic adjustment capabilities in the pump architecture. Components such as the plunger rod length, clamping force, and mounting positions can be adjusted or changed based on the specific syringe being used, allowing the system to adapt its configuration rather than being fixed for a single syringe type.

Inventive Principle:

Principle #15Dynamics

3Device complexity

If a syringe pump uses a single sensor for occlusion detection, then device complexity is reduced, but detection reliability is compromised

Engineering Contradiction:

Improvedevice complexityVSAvoidocclusion detection reliability

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The patent applies local quality by placing sensors at different locations within the fluid path to detect occlusions at various points. Instead of using a single sensor, the system employs multiple sensors (such as pressure sensors or flow sensors) positioned at different locations to provide localized detection, improving overall reliability through distributed sensing.

Inventive Principle:

Principle #3Local quality

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 precise and flexible administration of medications across various syringe sizes, reduces errors due to lead screw runout, and effectively detects occlusions, ensuring reliable and accurate fluid delivery.

Implementation Method 1

Methodology Applied

Scientific EffectLead screw mechanism: Screw

Implementation Method 2

incorporating a sliding block assembly with a cam mechanism for engaging and disengaging with a lead screw

Methodology Applied

Scientific EffectCam mechanism: Cam

Implementation Method 3

along with a method to mitigate lead screw runout using rotary and linear position sensors

Methodology Applied

Scientific EffectPosition sensing:

Data Source

PatentUS20240082487A1Syringe Pump, and Related Method and System

Publication Date: 2024.03.14 DEKA PRODUCTS LP

AI summary

A syringe pump includes a lead screw, a cam, and a grasper. The grasper assembly has first and second graspers arms each having a first end and a second end. The second ends of the first and second grasper arms are configured to engage with the lead screw. The first ends of the first and second grasper arms are configured to engage with the cam such that actuation of the cam toward the grasper assembly causes the second ends of the first and second grasper arms to pivotally approach each other. The second ends of the first and second grasper arms each includes threads to engage the lead screw when the second ends of the first and second grasper arms approach each other. The plunger head coupled to said grasper assembly and operative to drive a plunger of a syringe into a barrel of said syringe.