C3 Logix

The Cleveland Clinic Concussion App, also called C3 Logix, was developed to bring standardized concussion care to athletes.

Posted on April 6, 2023 by Mike Buss

C3 Logix

There are over four million sports-related brain injuries each year. I was hired at Cleveland Clinic to build C3 Logix to help address this problem.


The C3 Logix application is designed to assess balance, reaction time, vision, and memory. When an injury occurs, the app compares post-concussion data with the athlete's baseline data to determine when it is safe to return to play.

The app is designed to be used by athletic trainers, physical therapists, and physicians.

Vision test being administered
Vision test on an iPad

My Role

I was one of two iOS developers on the C3 Logix iPad project and developed approximately half the codebase. I designed the UI/UX for the iPhone version.

When the company NeuroLogix Technologies formed, I continued to be responsible for supporting the development of both iPhone and iPad applications.

Magazine highlighting the app

Design Process

The design process for C3 Logix started with what are called modules. A module is a test the athlete takes to measure a particular function, such as balance, reaction time, or vision. Most of these iPad tests are based on existing low-tech solutions.

Our team took great care in replicating the existing measures as closely as possible. Tests that initially existed on paper were converted to the iPad form factor and validated.

Graded Symptom Checklist
Graded Symptom Checklist
Graded Symptom Checklist

Some modules, however, did not have a paper equivalent. The Balance module uses the device's accelerometer and gyroscope to measure postural stability while strapped to the patient's waist.

Balance Module

Reaction time was another measure important to concussion management. To help with this, we developed the Simple Reaction Time and Choice Reaction Time modules.

The app shows the user a symbol on the screen and then quickly swaps it with one or two different symbols. The user's reaction time is then measured.

Reaction Time
Reaction Time

Users collect baseline assessments at the beginning of the sports season. When an athlete suffers an injury, their athletic trainer reports the incident in the app, along with a survey about the patient's health.

This information, along with a comparison of the athlete's baseline performance, helps give an overall view of the athlete's health.

Reaction Time
Reaction Time


The biggest challenge that faced the C3 Logix application was internet connectivity. Letting users log in and perform an assessment without reliable WiFi, while also restricting access to protected health information (PHI), was a significant hurdle.

With unreliable WiFi, we also ran into the problem of uploading large objects to the cloud, including the motion capture data from the Balance test.

To solve this problem, our team created a synchronization engine that allows the app to function offline. The app uploads assessments as soon as WiFi becomes available and resumes later if the connection was terminated prematurely.

Users log into the app with cached (encrypted) credentials, ensuring athletes always get the best standard of care - even when they are on the football field!

Featured on Apple.com

How Success is Measured

The app has successfully increased the standard of care for concussed athletes across the U.S. The insights the app have generated are now available to athletes who would not have otherwise had access to providers with experience in managing concussions.

Decisions surrounding return-to-play and return-to-school can now be more consistent, given the objective, quantitative data the app provides.

The app has also successfully improved the continuity of concussion care and the handoffs between care providers.

Final Result

The C3 Logix app is used in all 50 states and has collected assessments for over 300,000 athletes.

The Cleveland Clinic is currently adapting the technology for use in other populations such as: deep brain stimulation (DBS), mild traumatic brain injury (mTBI), Parkinson's disease (PD), stroke.


In 2014, the C3 Logix application was featured on Apple.com as part of their "What will your verse be?" campaign.

Featured on Apple.com

No real patients are depicted in any of the above photos. Stock photography from Shutterstock.com.