BME Projects
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Tools
SolidWorks
Keyshot
Arduino
Illustrator
Keyshot
Arduino
Illustrator
Time Frame
6 Weeks
Spring 2021
BME Design
Spring 2021
BME Design
Collaborators
Liz McCullogh
Nikhila Vembu
Harper Weigle
Nikhila Vembu
Harper Weigle
Two medical 'devices' were conceptually developed for a BME capstone class. One is a compact ECG that reads your heart activity via bluetooth connectivity. Another is an arm rest that immobilizes your arm for a non-contact extravasation procedure.
What is an ECG?
An Electrocardiogram is a device often used by nurses and EMTs to measure a patients heart activity. Usually there are 12 leads thats connect to various parts on your body which attaches to an external machine via wires.
The Pocket ECG
A compact, lightweight, and easily-transportable ECG device for use by healthcare professionals to simplify and ease transition between patients and save time and energy throughout the ER/hospital floor.
I. Background Research
What is an ECGs Medical Significance?
1. ECGs are used worldwide in hospitals for cardiac imaging & disease detection.
2. The standard setup is 12 connection points for clearest voltage signal but time consuming.
3. In ER: ~90 uses per day (5 min setup time) => ~8 work hrs a day.
1. ECGs are used worldwide in hospitals for cardiac imaging & disease detection.
2. The standard setup is 12 connection points for clearest voltage signal but time consuming.
3. In ER: ~90 uses per day (5 min setup time) => ~8 work hrs a day.
Understanding the current method
In order to fully understand the needs for using an ECG, I wanted to understand the type of illness that would require the administration of an ECG. Atrial Fibrillation is the most common heart disease detected by an ECG, hence I chose it to better understand how various stakeholders intervened at different points of the process from diagnosis to treatment.
Stakeholder Research
To better understand how an ECG is actually used, I talked to some contacts that have experience working with ECGs to understand what needs to be improved and what they hope to see for future designs of the ECG.
"Finding a solution for ECGs to be more sensitive to shaky patterns given off by muscle tremors and to be able to differentiate that from the heart rate sensing in the pre-diagnosis will save doctors a lot of time. "
Dr. Amir Reihani, MD, MPH
"The biggest problem with the ECG is that it is prone to inaccurate readings even if someone is highly experienced with using it.
One patch would not be able to accommodate for various sizes of people."
Vivian Hui, Nurse
"A common mistake for new people are that they inverse the leads so the leads don’t correspond to the correct area. In emergencies, technicians/nurses should have to manually check where each lead goes and could do it instantaneously."
Ferdy, EMT Paramedic
Key Takeaways: The Pain Points
• It is hard to transport due to the inefficiency of the wires that connect the leads
• Noise from muscle tremors are often recorded which results in inaccurate readings.
• There are many leads that have wire connectors which make it a time consuming and error prone process to administer.
• It is hard to transport due to the inefficiency of the wires that connect the leads
• Noise from muscle tremors are often recorded which results in inaccurate readings.
• There are many leads that have wire connectors which make it a time consuming and error prone process to administer.
II. Concept Development
Before delving into ideation, mapping out the touch points in the process of applying a pocket ECG helped us understand the intricacies of what needed to be done by each stakeholder in relation to these touchpoints.
Idea Generation Workshop
I organized a workshop between me and some other mechanical engineers on the team so we could co-create potential designs. I wanted to involve the engineers in this design process because they had a better understanding about the limitations of technology which might potentially affect the design.
Storyboarding how a pocket ECG would potentially be used in an ambulance, which is the most common environment for an ECG test.
We landed on a patch design that would combine 7 core leads in one connected material piece. This design is ideal as there is no need for repositioning the leads and having them as separate pieces.
III. Physical Prototyping
The electrical engineers on our team were able to prototype the signal sensing and processing system of an ECG out of Arduino, however, given their limited technical skills and funding, a wireless patch wasn't able to be produced in the end.
A diagram of the lead placements for the final demo product.
What is an Extravasation?
“The leakage of blood, lymph, or other fluid, such as an anticancer drug, from a blood vessel or tube into the tissue around it.”
Non-contact Extravasation Armrest
Due to the need for immobilization of the arm in order to get accurate imaging of the veins, a two piece arm rest was designed as part of this project's proof of concept
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I. Background Research
What is an Extravasation's Medical Significance?
For Hospitals
Up to 7.7 % of patients experience extravasations
Estimated 3 million extravasation cases
Around $3000 in liability cost per extravasation
Delay in patient discharging
Up to 7.7 % of patients experience extravasations
Estimated 3 million extravasation cases
Around $3000 in liability cost per extravasation
Delay in patient discharging
For Patients
Experience pain and discomfort
In extreme cases extravasations require surgery
Current methods cannot be used on all patients
Experience pain and discomfort
In extreme cases extravasations require surgery
Current methods cannot be used on all patients
Stakeholder Research
"Extravasations are very painful. The treatment process also has a psychological impact on me as I am afraid of getting injections and going to the hospital. "
Patient
"All nurses are busy, so they don't usually check the patient until the patients themselves notice something wrong. It might be too late by the time a patient notices something is wrong with their skin, and some patients don't even know whether the swelling on their skin is normal or not. "
Nurse
"When the injection is going in, most of the time the patient is stationary, but sometimes they move around and obscure the scanned image which makes the vein detection inaccurate."
Human Factors Engineer
Understanding the Procedure
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II. Concept Prototyping
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III. Physical Prototyping
In order to rapid prototype for the demo set up, we bent acrylic to the shape of the arm rest. The width, height and angle were all measurements taken from our demo user.
The Demo Set-Up
Takeaways
The medical significance behind both projects were really interesting to me so I learned a lot about heart diseases, reading ECG signals, extravasations etc. and the current problem spaces that healthcare workers face when using existing technology for these issues.
I also learned how to be more proactive in showcasing my design skills when working within an interdisciplinary team. At first I just did what my team members asked which wasn’t much so I just took it upon myself to do the animation and iteration sketches.
I also learned how to be more proactive in showcasing my design skills when working within an interdisciplinary team. At first I just did what my team members asked which wasn’t much so I just took it upon myself to do the animation and iteration sketches.