Project Motivation, Needs, and Goals
Experimental setup
My name is Paris Brown and I’m a MS student in the MEMS department. Having graduated from a medical high school, I have always had an interest in the medical field. When I chose to major in engineering, I still wanted to combine my mechanical skills with my passion for medicine. A great way to do this is with medical devices. Because I am specifically interested in robotics, working on a medical robot seemed to be the best option.
I was inspired to work on this type of robot from research currently being conducted in the Duke Acute Care Technology lab. Their robot uses a strain gauge to detect IV needle displacement when it encounters blood clots. My robot is a simpler version. It will detect the force of the needle as it enters the vein and display the data as a force vs time graph. Although the current focus of this project is to detect the force of the vein, this is a crucial step in developing an autonomous robot that will be able to determine when to stop inserting the needle.
In the future I would like for this robot to become fully autonomous in the sense that it will be able to detect a vein using cameras/computer vision and safely insert a needle into the skin with ease. Medical malpractice from intravenous device errors is a leading cause of death in the US. Inserting the needle incorrectly can cause air embolisms which can be fatal. Other than fatalities, incorrect IV procedures can cause pain, bruising, and leaking blood/fluid. This robot will be able to remove human error and insert an IV more efficiently which can essentially save lives.
Learning Objectives
The objective of this project is to create a robotic arm that will have the ability to locate a vein and insert an IV.
This project includes four main focus areas:
- Processing/Controls
- Sensors/Data Analysis
- Design & 3D Printing
- Inverse Kinematics & Machine Learning
Current testing is being done on the correlation of different pitch angles of the needle and the force being applied to the needle from the vein.
On the left below is a picture of the silicone skin with veins that I will be using for this project along with the needle insertion angle. On the right is a figure showing how to properly insert an IV in a real life setting.
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- Silicone skin with needle insertion
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- Insertion angle
Project Vision
This project consists of multiple mini projects and can be split into four phases.
Phase 1 consists of the assembly of two simple robots that can be found on thingiverse. This phase will also introduce you to Arduino and how to use it to make the project more efficient.
Phase 2 consists of assembling a more difficult robot and learning how to control it with Bluetooth as well as PC. This phase also involves design and 3D printing techniques.
Phase 3 involves learning how to control the storeBOT through Arduino, control the linear actuator using two methods, and how to use a force resisting sensor. This phase also involves the combination of multiple of the previous projects in the other phases to make the force sensing vein robot.
Phase 4 is the last phase and involves machine learning, computer vision, inverse kinematics, and the injection mechanism of the syringe.
In order to familiarize yourself with robotics, I suggest working on two robots listed below to learn about sensors and controls. In addition to these two projects that have already been built in the lab, I have made some modifications that will be useful knowledge for the force sensing vein insertion robot. Click here to go to the beginner page for more details.
Topics:
- AlphaBOT Assembly
- BetaBOT Assembly
- ADXL335 & LCD Screen
- Pololu Control
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- alphaBOT
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- betaBOT
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Now that the basics are covered, we can start working on the main body for IV robot. This phase involves building the main body for the robot, 3D printing, and making adjustments to the robot to fit our needs. Click here to go to the intermediate page.
Topics:
- 3D Printing
- StoreBot Assembly
- Bluetooth/PC Control
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- Ender 3 3D printer
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- LeArm Assembly
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- Bluetooth App
This phase involves the use of motors and sensors to acquire data about the robot. This phase is very important as it involves the current progress of the force sensing vein insertion robot. Click here to go to the advanced phase.
Topics:
- Force Sensing Resistor
- Arduino Control
- Data Analysis
- Linear Actuator & Controller
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- Linear Actuator
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- L298N
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- FSR
This phase is where the current progress of this project stands. After completing all of the tasks from the previous stages, one can combine them with a few extra materials to create the force sensing vein insertion robot.
This last phase has not been completed yet and is dedicated to future work of the project. This phase is labeled as advanced, but is more so about areas of the project that I did not get to complete during the spring 2021 semester.
Topics:
- Inverse and forward kinematics (ROS)
- Machine learning
- Injection mechanism
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- Injection Mechanism
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- Inverse Kinematics
For now, the robot is using a syringe needle to detect the insertion force. But, I would also like for there to be a mechanism that will be able to insert fluid into the vein.
Inverse and forward kinematics play a large part in having the robot move autonomously. Forward kinematics is not too difficult as it is just giving each joint of the robot a degree to move to that the end effector will go to a specific place. Inverse kinematics, on the other hand, can be somewhat difficult. There is an open-source framework called robot operating system (ROS) that can be used to help create the complex movements of the robotic arm. For more information about ROS, click here.
Machine learning and computer vision is also something that I would like to incorporate into this project for full autonomy. There could be an infrared sensor at the bottom of the silicone skin that will help illuminate the veins. Attaching a camera onto the end effector of the robot and using openCV will allow the robot to detect the vein. But, the robot also needs to understand when to stop inserting the vein, and also determine the best vein to select from multiple.
Instructional Video: Sensors
This is a video of a brief overview on how a 3 axis accelerometer works and how a force sensing resistor works. I’ve experimented with quite a few sensors during the progress of this project and it is important to not only know how to use and code them, but how they work as a MEMS device as well.
About The Author:
Howdy! My name is Paris Brown and I am a first semester (starting Spring 2021) mechanical engineering MS student.
I have my BS in mechanical engineering technology from the University of Houston and have almost completed flight school for my private pilot license. I have a passion for aviation, medicine, and innovation.
Last Updated: May 2021
