MicroDose-Efficient Syringe Pump for Controlled Fluid Delivery

Table of contents

MicroDose-Efficient Syringe Pump for Controlled Fluid Delivery

Abstract

Infusion pumps are critical for administering precise amounts of medication or fluids. The high cost of conventional infusion pumps limits their availability in developing countries. My goal is to develop a low-cost, simplified and easy-to-use version, a syringe pump, which may help addressing this gap, especially for rural and low-resource healthcare settings where affordability and simplicity are paramount.

** I am way behind the schedule, it's over now... I couldn't manage to post the updates regularly and I am sorry for that **

** I am posting this one single blog to briefly post the update of my project.**

** It's partially updated, I hope I'll be able to complete next week **

Introduction:

Syringe Pump – a simplified version of infusion pump… That’s what this project aims to.

 To validate the potential use of TMC5272-EVAL-KIT, NEMA 17 stepper motor, and provided PSU to design and develop a low-cost infusion pump - targeted to meet the needs of healthcare facilities in developing countries.

Objective:

Goal is to explore a basic design which will be compact and straight forward to make it user friendly to create a cost-effective solution suitable for resource-constrained environments.

Background:

  • What is a syringe pump –

Syringe pumps are powerful and precise medical devices designed to deliver fluids or medications in controlled amounts. They consist of a motor-driven mechanism that pushes the plunger of a syringe, enabling the gradual administration of liquids with exceptional accuracy and consistency. These devices are widely used in various healthcare settings, including hospitals, research laboratories, and ambulatory care centers.

What sets syringe pumps apart is their ability to deliver fluids at extremely low flow rates. [auxo medical]

https://24x7mag.com/medical-equipment/testing-calibration/principles-methods-testing-infusion-devices/

  • Difference between syringe and infusion pump –

Syringe pumps are designed to deliver small volumes of fluids or medication with high accuracy and precision. They utilize a syringe mechanism that allows for controlled and gradual administration. On the other hand, infusion pumps are typically used for larger volumes and provide a continuous flow of fluid over an extended period.

One notable difference is in the mode of operation. Syringe pumps operate based on displacement, meaning that the plunger of the syringe is pushed down gradually to administer the desired amount of fluid. In contrast, infusion pumps use a positive pressure system to deliver fluids at a constant rate. [auxo medical]

https://www.team-consulting.com/insights/infusion-pumps-why-theyre-actually-not-pumping/https://www.team-consulting.com/insights/infusion-pumps-why-theyre-actually-not-pumping/

      

  • Functions -

It can be automatic or manual driven. And there should be option for precise location detection to measure the fluid flow. The device should get feedback to prevent or notify any sort of blockage.

Agena medical

  • Motivation -

Our team at Biomedical Physics and Technology, University of Dhaka developed a prototype for testing, a few years ago. My colleague, a young research fellow Mr. AlAmin worked on it and he came up with a primary design. Later on we couldn’t carry on this project. The images are given bellow –

I got enthusiast to try out the TMC5272-EVAL-KIT, NEMA 17 stepper motor in this project and that brings it back alive!

{gallery}Primary prototype from BMPT, DU

image

Top view: Top view of the syringe pump

image

Plunger: plunger and the syringe clamps

image

Mechanism: The threaded rod, coupler and a DC geared motor

image

Mechanism: The linear motion mechanism attached with a bearing at one end

This design had some limitations like -

  • DC geared motor doesn't provide the required accuracy
  • There is no position / location feedback
  • No additional sensors attached

Therefore, I am considering these scopes of improvement for this design challenge by -

  • Replacing the DC geared motor with the NEMA stepper motor
  • Utilizing the rotational step count for precise control
  • Adding sensors for safe operation

Description:

  • Mechanism -

image

** the flow rate sensor is optional.

  • Block Diagram -

image

  • Controller (TMC5272-EVAL-KIT):
    • Acts as the main control unit, managing the stepper motor and interpreting user inputs.
    • Integrated diagnostic features will support monitoring for potential errors such as over-current or thermal shutdown.

  • Stepper Motor (NEMA 17):
    • Drives the syringe plunger with precision, adjusting the flow rate as per the set parameters.

  • User Interface:
    • Display shows real-time status, flow rate, and error notifications.
    • Push buttons allow users to set parameters, start/stop infusion, and respond to alerts.

  • Additional Sensors:
    • Position or encoder sensors for real-time feedback and calibration of motor positioning.

  • Alarms and Safety Systems:
    • Audio-visual alerts for low power, flow obstructions, and other safety-critical conditions.

System workflow

  1. Users set the desired flow rate and volume on the display.
  2. The TMC5272 controller processes inputs and directs the motor accordingly.
  3. The stepper motor moves the plunger of the syringe, delivering fluid at a controlled rate.
  4. Diagnostic functions of the TMC5272 monitor for errors and initiate alerts if detected

to be continued...

**I'll come up with the assembly part day after tomorrow. And then I'll post the final setup and operation update which I am still working on

Category : project