# XiHan Snore Coach: Privacy-First On-Device MedTech Guardian powered by Gemma 4 Mobile > Source: > Published: 2026-05-23 15:55:55+00:00 This is a submission for the Gemma 4 Challenge: Build with Gemma 4 XiHan Snore Coach is an Android-based MedTech application designed to help users track, analyze, and alleviate snoring and sleep apnea symptoms. In the medical health sector, privacy is paramount. Users are hesitant to upload highly sensitive physiological data—such as SpO2 (blood oxygen) levels, snoring audio metrics, and sleep disruption patterns—to cloud servers. To solve this, I built an entirely offline, on-device AI Sleep Coach. It acts as a pocket medical analyst, allowing users to ask natural language questions about their sleep trends and receive actionable respiratory muscle training plans without a single byte of their personal data leaving their phone. *https://youtube.com/shorts/ECAjo9r7Yew * https://github.com/yueliao11/sleepcoach.git To make this offline MedTech guardian a reality, I chose the Gemma 4 2B/4B Ultra-Mobile Model. Here is why it was the absolute right tool for the job and how it powers the core experience: get_local_sleep_history ). This function queries the local Android Room/SQLite database for the last 7 days of SpO2 and Snore data, feeding it back into the model's context. Gemma 4 proved that we no longer have to compromise between advanced AI reasoning capabilities and strict patient data privacy. This submission was published on behalf of the team by @your-dev-username. Contributors: Contributors: