Mentalys

An Android app for early depression-risk screening that combines a PHQ-9 questionnaire with on-device facial and speech emotion recognition.

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(Year): 2026
(Role): ML Engineer & Android Developer
(Stack)
(Type): Undergraduate Thesis / Android App

Mentalys presentation showing face analysis, home and screening result screens on three phones over a dark green background.

Mentalys welcome screen, login form and home screen with screening shortcuts and specialist cards.

(Problem)

Questionnaires alone miss signals that show in a face or a voice, and sending raw camera or microphone data to a server raises privacy concerns for a mental-health tool.

(Approach)

I trained a VGG-16 + SE + attention face model on FER-2013 and a CNN-BiLSTM voice model on MFCC features from RAVDESS, exported both to TensorFlow Lite and ran them on the phone. A deterministic formula fuses PHQ-9, face and voice risk, with a safety override for severe PHQ-9 scores or any self-harm answer. Gemini only explains the result. Four TypeScript and Express services on Cloud Run handle accounts, history, content and clinics.

(Result)

Test accuracy of 68.3% for the face model and 97.2% for the voice model, with on-device inference of about 0.33 s and 0.02 s on an Android 15 phone. Raw face and voice recordings stay on the device. It is a screening aid, not a diagnostic tool.

97.2%Voice model accuracy

68.3%Face model accuracy

3Screening modalities

Mentalys screening hub with three pending checks, followed by the first and later PHQ-9 questionnaire pages.

Mentalys face expression analysis, voice tone analysis with a 30-second timer, and the screening hub with all three checks done.

Mentalys screening result: Minimal risk score of 0.20, AI interpretation and summary, then crisis guidance and disclaimer.

Mentalys Ask AI chat screens and the mental test history list.

Mentalys Pedia home with food recommendations, the mental health article list and an article detail page.

Mentalys home screen with music and daily tips, a recipe sheet in Mentalys Pedia, and the settings screen.

(Next project)

FishPro →