The Patch · La Patch — An on-device, bilingual, n-of-1 method for everyday fatigue, crashes and gut symptoms: method, design rationale and safety rules (v1.0)

The Patch is a free, bilingual (English and Canadian French) web application for adults who feel tired, crash during the day, sleep badly, or have loose stools or headaches, and who often run on coffee, energy drinks or alcohol. It runs entirely on the user's phone. Seventeen questions (eighteen for people who drink) produce a one-week patch and the blood test to ask for. A daily check-in and an optional food log then feed three comparisons: habits against sleep and energy, families of foods against bad days, and the meals in the hours before each timed crash or symptom. A path orders the next steps — the basics, then blood work, then the most likely suspect, tested two weeks at a time against the four weeks before. Thresholds were set and checked by simulation; no real-user data exist yet. This document records the method as of 7 November 2026 and is deposited as prior art.