SGAdd photo
Sujay Godala
Co-founder
Why I’m building this…
See disease
where it starts
Captrail is a low-cost nailfold microscope that uses AI to flag early signs of autoimmune and vascular disease, so a doctor can take a closer look sooner.
“The earliest signs of systemic sclerosis can show up in vessels thinner than a hair. Everyone deserves to have them looked at, not just people near a specialist clinic.”
Our purpose
The Captrail team
“Captrail doesn’t diagnose. It gives a doctor a clearer, earlier reason to look closer.”
How we think about AI
The Captrail team
“If the hardware fits on a desk and costs a fraction of clinical equipment, screening can go where patients already are.”
Why low cost matters
The Captrail team
The Captrail scan
A specialist’s first look, built from parts that fit on a desk
Captrail turns a USB microscope, a 3D-printed finger cradle and a calibration slide into a repeatable scan: every image measured in micrometers, every flag explained, and every decision left to a clinician.
SCROLL
How it works
From fingertip to flag, layer by layer
Hardware at the bottom, software on top. Scroll, or tap any layer, to see what each one does.
01
In progress
Hardware to software
How the build talks to the model
Four physical parts feed one software pipeline. What comes out is a set of measurements and flags a doctor can check, never a diagnosis.
Hardware
Source 013D-printed finger cradle
Source 02Celestron Labs 2MP USB microscope
Source 030.01 mm calibration slide
SupportMineral oil for clear skin
CAPTRAIL SOFTWARE
Analysis
- 01Capture · sharpest frames over USB
- 02Calibrate · pixels to micrometers
- 03Detect · AI marks abnormal patterns
Every measurement traces back to the calibration slide.
Output
MeasureLoop width in µm
MeasureCapillaries per mm
FlagsGiant loops, bleeds, dropout
ThenSent to a clinician for review
Who it's for
Earlier referrals, wherever patients are.
The build
Everything it takes, on one list
One 3D-printed part, a USB microscope with its own stand, and a few inexpensive supplies. No motors, no custom mount, no second focusing mechanism.
Total build cost
$—
Add the real total once every part is tallied.
| 01 | Celestron Labs Digital 2MP Handheld Microscope + included stand1920 × 1080 images, 20–200× advertised magnification, built-in LED lighting | $ TBD |
| 02 | Attune 3D-printed finger restSteadies the finger without pressing on the nailfold | $ TBD |
| 03 | MUHWA 0.01 mm calibration slide10 µm divisions to convert pixels into micrometers | $ TBD |
| 04 | Mineral oilOne tiny drop on the nailfold cuts surface glare | $ TBD |
| 05 | Microfiber cloth and cotton swabsCleaning the lens and applying or removing oil | $ TBD |
| 06 | Black cardstock (optional)Blocks reflections and stray light | $ TBD |
Finger rest design credit: Attune (dlx-designlab). Plus a computer and the microscope’s USB cable.
Read the full build guide →PhotoThe printed finger rest
PhotoThe microscope on its stand
PhotoThe full setup
Results
Real data only
Scroll through each stage. Every number here comes from our own tests, and blank means we don’t have it yet.
Safety and limits
Captrail is a research prototype for screening and referral, not a diagnostic tool. It does not replace a doctor.
Consent first
We get consent before imaging anyone, every time.
How images are handled
Whether scans are stored, how they are anonymized and who can see them.
Fill in your policyA doctor decides
Flags are a reason to look closer. Only a clinician interprets them.
Who we are
The founders
Four students building a cheaper, faster way to spot disease in the smallest blood vessels.
SRAdd photo
Smyan Reddy
Co-founder
Why I’m building this…
ASAdd photo
Aryan Senthilkumar
Co-founder
Why I’m building this…
AMAdd photo
Ansh Mishra
Co-founder
Why I’m building this…
Get in touch
Help us take
a closer look.
Clinicians, researchers and anyone curious about nailfold capillaroscopy: we’d love to hear from you.
