Passive Colorimetric H2S Exposure-Dosimeter Wristband with AI-Based Quantitative Reading
Mangalore Refinery and Petrochemicals Limited (MRPL) · Miscellaneous · Hardware
Beautifully specified and largely unbuildable — the app and the lighting correction are honest work, but without lab-generated calibration exposures the dose figure is uncalibrated, and you must say so rather than presenting a number that looks measured.
What it actually is
Oil and gas workers absorb low-level hydrogen sulphide over whole shifts, and electronic detectors only alarm on instantaneous concentration, missing the cumulative dose that actually damages health. Existing passive badges give a rough eyeball reading. The ask is a disposable wristband whose chemical strip darkens progressively with total exposure, read quantitatively by a phone app that corrects for lighting.
What to build
A disposable wristband carrying a chemical strip that darkens progressively and permanently with cumulative hydrogen sulphide exposure, printed alongside a reference colour scale and a separate patch indicating the badge's own remaining shelf life so a worker can confirm validity before a shift, paired with a phone app that photographs the strip against the reference scale, colour-corrects for ambient lighting using that reference, converts the corrected colour into an estimated cumulative dose in parts-per-million-hours with compensation for temperature and humidity effects on reaction rate, and logs the result against worker identity and shift for occupational health records.
Smallest thing that wins the room
Photograph strips exposed to known cumulative doses under three different lighting conditions and show the app returning consistent dose estimates each time, proving the reference-scale correction works, with the readings tracking the known exposure levels.
How crowded this one gets
A guess, projected from the 2025 statements — the last year where both the submission counts and the winners were published.
Quieter than 95% of the 226 · #13 of 226 by expected field
Few teams are likely to go here. The best odds on the board come from statements like this.
Why: company-sponsored statements drew the smallest fields of all; hardware halves the field a software statement gets.
This is a guess, not a fact
Nobody has published 2026’s numbers yet. This is an analysed estimate from last year’s pattern, so please do not take it as the truth — check the live counter on the SIH portal before you decide anything. The range covers the middle half of likely outcomes, so one statement in two lands outside it. Entry closes at 500 ideas per statement, so no range goes past that — a statement that reaches the cap fills and shuts rather than drawing an unlimited crowd. The model reads only three things a team can see before choosing — software or hardware, the theme, and what kind of body posted it — and those explain about a quarter of the variation in last year’s field sizes (R² 0.25 on held-out statements). Trust the band more than the number, and the ordering more than either. It cannot see how good your idea is, which is the part that actually decides it.
The scores
The number is the shorthand. The line under it is the reason.
Acceptance potential
2/5An unusually well-written statement with an unbuildable core — the indigenous chemical formulation and its dose calibration require a chemistry lab and lethal gas handling, and an app that reads colour swatches accurately has demonstrated the easy half while the safety-critical half remains unproven.
Feasibility
2/5The description requires testing against controlled lab-simulated hydrogen sulphide at known concentrations, and hydrogen sulphide is acutely lethal — generating calibrated exposures needs a fume hood, gas standards and safety protocols a student team cannot access, so the strip cannot be calibrated or validated.
Innovation scope
4/5The chemistry formulation, the shelf-life indicator mechanism and the temperature and humidity compensation approach are all left to you, and the description explicitly offers alternatives such as a sealed reference cell or software compensation.
Clarity
5/5The description is exceptionally precise, naming the deliverable components, the reference-scale correction method, the expiry patch, the dose-versus-threshold distinction, and even acknowledging that colorimetric response is nonlinear and temperature-dependent.
Effort
MassiveChemical strip formulation, wristband construction, an expiry indicator and a colour-calibrated phone app is a chemistry project and a software project running in parallel, with the chemistry gated on lab access.
Demo-ability
HardYou cannot safely generate controlled hydrogen sulphide exposures, so the strip's dose response — the entire point of the device — cannot be demonstrated, leaving you showing an app reading colours from surrogate samples.
In its favour
- Green flag: The reference-scale-in-frame approach to lighting correction is a genuinely sound method and the app half can be built and validated properly with printed colour standards
- Green flag: The shelf-life indicator patch is a small, clever feature that addresses a real gap in existing badges and costs almost nothing to design
- Green flag: The description honestly acknowledges nonlinearity and environmental effects, which tells you exactly which caveats your presentation must carry
- Green flag: Cumulative dose rather than peak alarm is a genuinely correct occupational health framing that will resonate with a safety judge
Against it
- Red flag: Hydrogen sulphide is lethal at low concentrations and generating calibrated test exposures requires laboratory infrastructure and safety clearance no student team has
- Red flag: Without calibration exposures there is no dose-response curve, so the app converts colour into a number that has never been anchored to reality
- Red flag: Formulating an indigenous chemical strip with a progressive rather than threshold response is a materials chemistry problem, not an engineering one
- Red flag: An occupational health device that under-reports exposure has direct consequences for a worker's health, so unvalidated dose figures are a serious claim to put in front of a safety judge
What you will be writing
- Lead acetate or metal-salt colorimetric chemistry
- Reference-scale colour calibration (ColorChecker-style)
- OpenCV white balance and illuminant correction
- Dose-response curve fitting
- Flutter capture app with worker ID logging
- Temperature and humidity compensation modelling
- Occupational health monitoring
- Colorimetric sensing
- Industrial safety
Prior art to read before you start
passive cumulative exposure dosimetry · smartphone colorimetric quantification · worker health record logging
Analysed by Claude Opus. Every score above is a judgment call with its reasoning attached — kindly cross-check this against the official statement on the SIH portal before your team commits to it.