Passive Colorimetric H2S Exposure-Dosimeter Wristband with AI-Based Quantitative Reading
“Workers in oil refineries are exposed to invisible, toxic gas that causes long-term health damage, but current detectors only warn them if the gas level is dangerously high right now. You are building a low-cost, wearable wristband that changes color as it absorbs gas over time, paired with a smartphone app that scans the color to calculate the total amount of gas the worker has inhaled.”
Deconstructed Problem Blueprint
WHAT TO BUILD?
A hybrid system consisting of a passive colorimetric chemical-strip wristband (hardware) and a computer-vision-based mobile application (software) for quantitative exposure tracking.
WHO IS IT FOR?
Primary beneficiaries are oil and gas field workers; users include safety officers, industrial hygienists, and health compliance departments (DGMS/OISD).
WHY DOES IT EXIST?
Existing electronic sensors are expensive, require calibration, and fail to track cumulative 'dose' (time-weighted average), which is the true driver of chronic occupational illness.
INPUT → PROCESS → OUTPUT ARCHITECTURE PIPELINE
Smartphone camera images of the wristband strip, reference color scale, and expiry indicator patch; metadata including worker ID and shift timestamp.
Color normalization using the reference scale to negate lighting conditions; image processing to calculate RGB/LAB color shift; mapping color intensity to cumulative H2S dosage using a pre-trained regression model.
Cumulative exposure report (ppm-hours), health risk status, digital log for compliance reporting, and expiry validation alerts.
CONSTRAINTS
- Must function under variable ambient lighting (indoor/outdoor/night)
- Chemical strip must be stable and shelf-life validated
- Offline-first mobile app capability for remote refinery sites
- Must account for temperature/humidity interference in chemical reaction rates
JURY METRICS
- Colorimetric accuracy (Delta E) under varying light
- Correlation coefficient between app-calculated dose and lab-simulated dose
- User interface simplicity for non-technical workers
- Cost-per-unit of the disposable wristband
CORE BOTTLENECK
The chemical formulation of the strip that ensures a permanent, non-reversible, and linear color change relative to H2S concentration without being overly sensitive to ambient humidity.
Why You Should Choose This PS (Pros)
- High social impact and direct alignment with industrial safety mandates
- Clear, tangible hardware-software integration
- Strong potential for patenting the chemical strip formulation
Challenges & Risks to Watch (Cons)
- Requires actual chemical prototyping which is difficult in a 36-hour hackathon
- Need for controlled lab environment to validate the 'dose' accuracy
- Complex calibration logic to handle environmental noise
Recommended Tech Stack & Grand Finale Features
Killer Features to Impress the SIH Jury
View Official SIH 2026 Portal Raw Text▼
A phone app does the reading. Photograph the strip next to the reference scale, and the app corrects for whatever lighting the photo was taken in by calibrating against that reference. It converts the color into an estimated cumulative exposure figure and logs it against worker ID and shift, for occupational health records and DGMS or OISD style reporting. The dose figure should be presented as an estimate, since colorimetric reactions don't scale perfectly linearly at very low concentrations or over long durations. Temperature and humidity affect reaction speed too, so the strip design needs to account for that, either through a sealed reference cell or a compensation method in the app.