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Our Device
Our Device
Autoinjector.mp4Background
Background
Nerve Block Procedure
Nerve Block Procedure
Image from Preetham J. Suresh, MD at UCSD
A common procedure in anesthesia is a nerve block, where an anesthesiologist injects a local anesthetic around a nerve while viewing the nerve using an ultrasound imagery.
A - Anesthesiologist holding ultrasound wand and positioning the needle
B - Clinician operating ultrasound imaging display
C - Clinician injecting/aspirating with a syringe connected to the needle
Two people are typically required to perform this procedure. The anesthesiologist needs full dexterity of their dominant hand to position the needle amongst fragile, millimetric structures. A relatively large 20cc syringe is typically used to hold the dose of anesthesia. This requires a second practitioner to be present to inject and aspirate the syringe as it is too large to operate while maintaining precision. The pressure felt when injecting is crucial information and informs the doctor of their next step in the procedure. Ideally, the doctor should feel this pressure and the procedure would only require one person. This is the problem our sponsor, Dr. Suresh, wishes to solve with a haptic feedback equipped auto-injector device.
Medical Devices
Medical Devices
In the medical devices field, there is a pressing need to make solutions more efficient, affordable, and easy to use for clinicians. This is especially important since they undergo physical and mental stress (we have seen this firsthand with COVID-19). Successful medical devices balance a clinician’s expertise with the assistance of medical technology.
The goal of our medical device is to reduce the procedure to a one person job without adding additional difficulty on the clinician side.
Objectives
Objectives
High Priority Objectives
High Priority Objectives
Second Priority Objectives
Second Priority Objectives
Functionality
Functionality
Design & build an autoinjector that can inject and aspirate a syringe
Must be accurate and successful in delivering the anesthetic with no danger to the patient
User-Friendly
User-Friendly
Intuitively activate injection & aspiration from the right hand with a button actuator system
Provide haptic feedback to the user on the button or another mechanism
Final Design
Final Design
Created with BioRender.com
Above is a diagram of our overall system with the hydraulic linear actuator and Autoinjector device shown. The resistive touch and Hall Effect sensors are located on the 3D printed injection controller. Buttons for Forward (F) and Reverse (R) are used to reposition the syringes in the hydraulic system.
To the right is an animated CAD model of our final autoinjector design. The device shown houses a 5cc syringe and injection needle. All components are 3D-printed.
Please explore our other pages for more information!
Results
Results
We were successfully able to create a medical device that injects and aspirates, provides helpful haptic feedback, reduces the procedure to a one-person operation, and offers an ergonomic design in the 3D printed controller. However, we were unable to maintain the standard 5cc per stroke workflow. The Auto-injector provides 1cc per injection stroke. Also, we were unable to achieve perfect 1:1 haptic feedback. Instead, our device provides a ratio of 1.2:1. Please refer to the Final Design page for graphs of this data.
To resolve these issues in the future, we have proposed several solutions in our Final Report. Please visit the Reports & Presentations section of our website for more information.
Despite these challenges, we were still able to produce a working prototype that received positive feedback from our sponsors. Thank you so much to Dr. Preetham Suresh, Dr. Matthew Swisher, Shiv Patel, and the rest of the staff at UCSD Medical Center!
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