CHROMA

What it does

CHROMA helps patients and medical practitioners monitor wound pH by applying a color-changing film and using an AI-powered app. A rising pH may indicate an infection, while a falling pH suggests healing.

Your inspiration

Diabetic wounds are slow to heal and prone to infection, making continuous monitoring critical to avoid complications like amputation. Yet, current monitoring methods often require frequent hospital visits, invasive procedures like biopsies, or subjective visual inspection—all of which are impractical, painful, or unreliable for regular use. This creates a major barrier for patients, especially those in rural areas with limited access to healthcare facilities. CHROMA was inspired by this pressing need: to offer a simple, non-invasive, and accessible way for patients and caregivers to track wound healing from home.

How it works

CHROMA consists of two key components: (1) a pH-sensitive color-changing film and (2) a mobile app powered by an AI model. The film is composed of three main materials: polyvinyl alcohol (PVA), which serves as the structural base; polyethylene glycol (PEG), a plasticizer that improves the film’s flexibility and responsiveness; and bromothymol blue (BTB), a dye that changes color in response to pH variations. In alkaline conditions, it shifts from yellow to blue, visually indicating changes in wound status. When placed on a wound dressing, the film reacts with the exudate and changes color according to the wound’s pH. The mobile app captures an image of the film using a preset mask, removing the need for manual segmentation. With a single tap, users can predict the wound’s pH level through an integrated AI model. The app stores each result in a local database, displays historical data, and allows users to export records as Excel files for tracking and analysis.

Design process

The idea for CHROMA began when I saw my grandfather suffer from a diabetic foot ulcer. Living in a rural area, the nearest hospital was over an hour away, and local clinics offered only basic wound cleaning. This made it clear that a more accessible and reliable way to monitor wounds outside hospital settings was necessary. Through research, I discovered that pH is a key biomarker of wound status—diabetic wounds typically become more alkaline when infected. This insight led to the concept of a non-invasive, painless method to monitor pH through color change. After months of formulation, testing, and refinement, I successfully fabricated a film that showed reliable color change across clinically relevant pH ranges. I then optimized key parameters such as swelling ratio, which affects how quickly the film absorbs wound exudate, and response time, which determines how fast the color shift occurs. Once the film met performance criteria, I developed a mobile app with a lightweight AI model. To validate the system, I collaborated with a local hospital to conduct clinical testing with real wound dressing samples. The results demonstrated that CHROMA could reliably estimate wound pH. With this foundation, CHROMA is now moving toward commercialization, aiming to empower patients.

How it is different

While monitoring wound pH is not yet a standard clinical practice, several studies have proposed using electrode-based sensors. However, these sensors often require direct contact with the wound, increasing the risk of wound contamination and causing patient discomfort. As a safer alternative, some researchers have explored colorimetric sensors that use pH-sensitive dyes to indicate pH changes visually. What makes CHROMA stand out is its rapid response time—the film completes a visible color change within just 3 to 5 minutes. In addition, most existing approaches rely on subjective color assessment. CHROMA overcomes this by integrating computer vision and an AI model into a mobile app, enabling objective, real-time pH prediction. By combining fast-responding smart materials, AI-powered analysis, and mobile health technology, CHROMA delivers a truly comprehensive and scalable solution for next-generation wound pH monitoring.

Future plans

With both laboratory and clinical testing completed, the next steps for CHROMA include further evaluations such as biocompatibility and biodegradation testing to ensure the product’s safety and suitability for real-world use. A user functionality study is also planned to refine the mobile application’s user interface (UI) and enhance the overall user experience. The ultimate goal is to commercialize CHROMA as an affordable and accessible wound monitoring solution—helping patients, especially those in remote and underserved areas, to monitor their wound healing from home and reduce the need for frequent hospital visits.

Awards

1. Outstanding Graduate Thesis Award – De La Salle University–Manila. 2. Research funding grant awarded by the Department of Science and Technology - Philippine Council for Health Research and Development (DOST-PCHRD). 3. Numerous publications presented and published in peer-reviewed journals and international conferences.