Med-tech device design for screening Deep-Vein-Thrombosis
Designing a Med-tech Device to screen patients for 'blood clots' formed during Deep-Vein-Thrombosis.
#healthcare #wearabletech #knitwear #medtech #problemsolving
Year / Duration
2019 / 4 months
Type
Freelance Project, commissioned by a Stanford Biodesign team
Hats worn
Design Consultant Lead
Collaborator
Antra Lodha (Knitwear Design),
Ashil Shaji (Illustration),
Tulika Saxena (Electronics),
Akhil Eugene (Photography)
" Deep vein thrombosis (DVT) is a serious condition that occurs when a blood clot forms in a vein located deep inside your body." - healthline.com
I was challenged to help a Stanford Biodesign Team (DVenTure) to design a consumer med-tech device for a novel imaging technology to screen Deep Vein Thrombosis (DVT)
The intervention is designed to rapidly screen clot formation in the deep veins of the leg. This device also allows you to screen in the earlier days, taking away the redundancy. Currently, This becomes expensive and even, fatal in some cases.
THE PROCESS
PHASE I
EMPATHISING with the problem statement through a series of interactions with the Core Team to understand the device, function, users and to detail out the requirements of the project.
WHAT : A Device used by high-risk patients to screen DVT.
WHO : Acute-rehab patients with high risk of clot-formation possibility
WHY : Early-stage screening will pick DVT earlier and help save monetary & life cost associated with the treatment. Repeated physical exams would become unnecessary.
HOW : Using novel-imaging technology
WHEN : For 30 minutes, thrice a week, for 3 months during high-risk period
WHERE : At hospitals (Ideally, at home)
BRAINSTORMING After empathising, we conducted a brainstorming session - to detail out possible user- interactions, touch-points, and body-constraints under which the design would be developed.
%20edit%202.jpg)
Brainstorming Canvas
As a deliverable,
we came up with a set of digital illustrations to shape the verbal interaction into a tangible format.
PHASE II
Based on the sketches, our team and the client team were able to gauge the thought-process and roadmap for the product development. It extended the discourse from verbal-discussions to lay down the constraints of the device which are mentioned below :
1. INCLUSIVITY
How will the device accommodate/include for leg-lengths and thigh of different sizes?
2. STRETCHABILITY
How should the 'electrodes' be placed so that they expand circumferentially in an equidistant manner?
3. POSITION
How to enable the patient to apply the band at the exact same position every time they screen?
4. COMPRESSION
How will the optimum compression [ < compression sock ] balance be found?
5. INVISIBILITY
The working electronics should be invisible to decrease the user's skepticism to use the device, enhancing the user-experience.
6. BAND CLOSURE
How to smartly design the band's closure in a way that it doesn't hinder the contiguous placement of the electrodes?
DESIGN & DEVELOPMENT
Bands + Socks Design
1. INCLUSIVITY
How will the device accommodate/include for leg-lengths and thigh of different sizes?
Advantages : Knitted fabric ; lycra is a 4-way stretch breathable material, it is comfortable and it allows for a good grip with a variation in knit structure. It can expand according to the structure provided.
This will help one size fit many.
However, proposal of minimum 3-5 sizes to be developed according to the anthropometric data.
.png)
Material : Knitted Fabric ; lycra / spandex
Band Material
The bands should be made of Elastic fabric with electrodes sewn in.
For convenience, the initial prototypes of the band should be modular to be able to experiment with electrodes placements to find the unique pattern.
2. STRETCHABILITY
How should the Electrodes be placed so that they expand circumferentially in an equidistant manner?
Wire Material
Which wire works the best for achieving stretchability?
.png)
Gauge of single stranded wire > gauge of 7 stranded wire.
The electrodes
In the future, the electrodes would be embedded into the fabric. This will help in uniform stretchability, reduce the material and manufacturing cost of the wires.
Mockup of electrodes in a band
Arranged electrodes in a linear fashion
3. POSITION
How to enable the patient to apply the band at the exact same position every time they screen?
For efficiency purpose, the bands are placed at the highest risk areas where deep venous clots are likely to be identified.
The Power-Knit will act as a visual cue within the sock too place the bands and connect to the PCB.
The current problem is left pending to be solved during the timeline.
The goal is to find a viable solution that fits the manufacturing paradigm.
.jpg)
4. COMPRESSION
The purpose of the compression sock is more focused towards adhering electrodes closely enough to the skin than to apply pressure.
How will the optimum compression
[ < compression sock ] balance be found?
Explore knitwear used in sportswear as a prototyping material. Sportswear, commonly used by atheletes are form-fitting and have lesser compression compared to 'compression stocking'. The material 'Spandex' is a diverse material that can be designed for specific needs.
5. INVISIBILITY
The working electronics should be invisible to decrease the user's skepticism to use the device, enhancing the user-experience.
The final product would be a combination of 3 bands as well as a sock as a package. Most of the wires will get hidden - which looks as good as a stocking. This could be worn underneath a regular pant and be completely sealed.
.jpg)
.jpg)
6. BAND CLOSURE
How to smartly design the band's closure in a way that it doesn't hinder the contiguous placement of the electrodes?
A concern we have is that the velcro pad does not allow for easy implantation of electrodes over the area, which breaks the contiguous ring of electrodes that is necessary for this imaging.
Placing the Velcro beyond the width of the band (housing electrodes) while still maintaining adequate adhesion
USER-INTERACTION
USER TESTING
FUTURE ROADMAP
1
Improving the band performance by re-routing the wiring.
-
Symmetrical routing of wires (length = x) will help reduce the unwanted resistance in wires (current length 2x) consequently improving the reading.
-
This will reduce the wiring material by 1.5x.
-
MUX's placement at the center will avoid tilting of MUX (as observed with it being placed at the end of the band in the current prototype).
.jpg)
.jpg)
Symmetrical routing of wires around the MUX located at the center of the band.
2
Develop a 2.5D Band.
-
The wire could be coiled and connected to each vertical slat holding the electrode.
-
This will help in integrating wires close to the band instead of hanging free in the air.
.jpg)
3
Rule out the sock and make a strap-adjustable system.
-
It will not only save materials and drastically reduce a lot of wastage, but also optimise the production.
-
Although the current sock's user-acceptance is higher, it should be included in the later stages of development after the functionality / user convenience has been resolved.
.jpg)
4
Product-development is a long-term commitment.
To conclude Phase III - the Product Development Ladder was handed over to the team.
