Application Cases of Integrated Miniature Slide Stages in High-Injection Imaging Equipment

In the field of precision medical equipment, the performance of contrast agent injection devices directly affects the accuracy of medical imaging diagnosis and patient safety. Traditional injection devices face challenges in injection accuracy, operational stability, and response speed, especially in high-pressure, low-flow contrast agent injection scenarios, which place extremely high demands on the positioning accuracy and dynamic performance of the drive system. Integrated micro-slide modules and integrated stepper servo motors, with their high integration, high precision, and intelligent control capabilities, have become ideal choices for improving the core performance of such devices. This article takes a high-injection contrast agent equipment project as an example to elaborate on the specific applications and value of integrated micro-slide modules and integrated stepper servo motors in this field.

I. Equipment Introduction

High-injection contrast agent equipment is a key device used in medical imaging examinations such as CT and DSA to accurately, stably, and controllably inject contrast agents into the patient's body. Its core lies in the drive system, which needs to precisely convert the rotational motion of the motor into the linear motion of the injection pusher to control the injection flow rate, flow rate, and pressure of the contrast agent.

II. Application Solution

To address the needs of intelligent contrast imaging injection systems, NiMotion proposed an injection module solution based on an integrated micro-slide stage module and an integrated stepper servo motor. This solution uses the integrated micro-slide stage module as its core, mounting it on the pump body and connecting it to components such as the syringe piston or screw via its linear guide rails. Controlling the movement of the micro-slide stage module achieves precise displacement control of the syringe piston or screw, thereby enabling precise delivery of minute amounts of liquid.

Product Models:

STM2851B-CANopen-MA Integrated Stepper Servo Motor

NMWX-2845-CANopen-MA Integrated Miniature Slide Module

Functions Used:

HM (Hollow-back Mode), PP (Profile Position Mode), and CSP (Cyclic Synchronous Position Mode)

III. Application Products

IV. Problems and Solutions

Problem: Slide jitter and inability to stop precisely during slide operation

Customer feedback indicates that the 28 series slides used for clamping or pushing hoses exhibit significant jitter when reaching the target position and occasionally fail to stop stably at the preset position, affecting the final accuracy and stability of the injection action.

Problem Analysis:

1. Load Characteristic Matching: The slide's operating condition is hose clamping, which is a load with elastic and non-linear characteristics. When the slide contactes the hose and begins to compress, the load's stiffness and damping characteristics change. General-purpose PID parameters may not be suitable for the entire motion process, leading to overshoot or oscillation during the positioning phase.

2. Control Parameter Optimization: Standard position loop gain parameters may be too "aggressive" for this type of variable load condition, easily causing system resonance when approaching the target position.

Solution:

To address the issue of "positioning jitter and inability to stop," the technical team implemented fine-tuning of the PID parameters.

1. On-site Diagnosis and Debugging: By connecting to debugging software and observing the position, speed, and current feedback curves of the slide during the hose compression process in real time, it was confirmed that oscillation occurred in the system after the contact point.

2. Parameter Optimization: Targeted adjustments were made to the motor's position loop PID control parameters. This was achieved by reducing the proportional gain (P) to decrease system stiffness, increasing the derivative gain (D) to suppress the rate of speed change, and appropriately adjusting the integral gain (I) to eliminate static errors. After repeated testing, the operating parameters were finally optimized and set to (300/200/2000) (these values ​​are exemplary PID parameter combinations).

3. Effect Verification: After parameter adjustment, the motion curve of the slide under the tube-pressing condition became smoother, and it could stop quickly and smoothly when reaching the target position, completely eliminating the shaking phenomenon and ensuring high stability at the end of the injection action.

V. Conclusion

This application case successfully demonstrated the powerful adaptability and value of the integrated micro-slide module and integrated stepper servo motor in high-precision medical injection equipment. Through reasonable structural design and control strategy design, precise delivery and control of micro-liquids can be achieved, providing strong support for the development of biomedicine, drug development, and precision manufacturing.

As medical equipment develops towards greater intelligence and automation, integrated products have broad expansion prospects in more scenarios such as micro-injection pumps and automated drug dispensing robots, and will continue to help improve the overall technical level and reliability of medical equipment.