Welcome to Big Yellow Star

We apply innovative information technology to real-world public health systems, such as improving health communications.


Health Data Science

Data Tools for Health Organizations

Health Data Science is a new suite of interactive, exploratory data tools for large sets of health data.

These are tools for clinicians and health organizations to integrate data from different sources and to perform some of the initial steps of data analytics.

Health Data Science The tools can work with Protected Health Information or de-identified data, and also incorporate publicly available data such as GIS layers.

They are customizable and work in a web browser using modern user interface technology for a powerful yet flexible user experience.

Mapping Health

Apps for Health Data

Mapping Health is a growing collection of original visualizations and apps for exploring or managing health data. The audience ranges from academics and health professionals to patients and healthy consumers.

The goal of Mapping Health is to use information tools to improve communication and understanding of health issues. We use recent advances in the fields of data collection and analysis, interactive visualizations, GIS, and other information technologies.

There are currently 16 projects on Mapping Health, and they are the recipients of 8 prizes from Health 2.0 and Challenge.gov.

Med Mesg

Mobile Health Reminders

  • Currently in use in two federally-qualified community health centers in Philadelphia.
  • Automated system for reminders and other routine communication with patients.
  • Uses SMS text messages and phone calls (IVR, interactive voice response) — under 5 cents per conversation.
  • Patients need only a cell phone, not a smartphone or other Internet connection.
  • Messages can be tailored to the individuals: their values, beliefs, obstacles, etc.
  • Multi-lingual option.

Improving high-risk population health through effective use of Community Health Workers

We developed the web site for this project and are helping to design a dynamic platform for coordinating community health worker based interventions.

Incubation for Health Care Innovation

Big Yellow Star developed the web site for this project and also participates in the lab as an advisory member on several projects.

Step Up to Cervical Cancer Prevention (in development)

With the University of Pennsylvania School of Nursing Science, we developed a mobile app for young women to coordinate tasks for cervical cancer prevention.

Optimizing the Mobile Experience for Doctors and Nurses (in development)

With Penn Medicine we are developing a mobile web app for hospital-based clinicians to collaborate on patient care. This is a mobile interface to the EHRs in three hospitals, designed closely with clinicians. It uses modern user experience design and performance tuning: for example by preloading patient data in a manner similar to how email apps load messages instantly.

My Game Plan app

Suicide Prevention App

My Game Plan is an iPhone app for patients discharged for suicide attempt. It helps them manage their appointments, safety plan, resources, and other important aspects of their care.


Reducing Risks for Women

Everhealthier Women is a mobile web app for women to manage preventativ health tasks. It sends reminders as interactive text messages. It also lets the user add family and friends in order to track their prevention tasks.

Everhealthier Women was designed and developed in collaboration with Anne Teitelman, PhD, FNP-BC, FAANP, FAAN, Marilynn Stringer, PhD, CRNP, RDMS, FAAN, and Ben Koditschek, BFA.

Winner in a Health 2.0 developer challenge and featured in the August 2013 issue of O (Oprah) Magazine.


Personalized Health Promotion Task List

Preventify.me is a mobile web app, designed for smartphones. It lists prevention behaviors and other tasks according to the age and sex of the user, and then lets the user track progress. It sends reminders as interactive text messages. It also lets the user add family and friends in order to track their prevention tasks.

Preventify.me was designed and developed in collaboration with Ian Bennett, MD PhD, Rosemary Frasso, PhD CPH, Lauren Hallden-Abberton, Alex Tam, and Amy Lee.


Crowdsourced Mapping of AEDs

We are developed an interactive map for viewing geographic data: MyHeartMap. We are now also building an iPhone app for this project.

There is a brief poster pdf for this site.

Epinephrine Reminder System via Text Messaging

For the University of Pennsylvania School of Medicine we developed a full platform for interactive messaging with clinical study participants about remembering epinephrine pens. Sending and receiving texts; administrative web interface for managing participants, messages, and data.


Preschool & Pediatric Care

PREPPED Kids is a multi-lingual web application for hyper-local mapping of preschools, pediatric/family medicine, and supporting resources. Focused on disadvantaged families, it also has SMS text messaging features.

It is a winner of two prizes by the FCC and Knight Foundation.

Global Health Jobs

Database of Global Health

A simple interface for finding global health job and internship opportunities. Database by the Akili Initiative.

Quality Care Navigator

Mobile Web Site for Quality Care Metrics

A bilingual web site providing detailed quality comparison of hospitals and outpatient facilities across a wide variety of metrics. Optimized for iPads and other tablets in addition to smartphones.

There is a presentation pdf for this project.

Patient Reporting App

iPad App in a Waiting Room

  • Patients in a primary care office use our native iPad app to answer targeted questions, while in in waiting room.
  • Answers are immediately accessible electronically by the physician.
  • Screening analysis is performed automatically and results are summarized.


Public Health Informatics

  • We collect big data, for example Twitter streams, using scalable databases such as MongoDB.
  • We do data processing and mining including indexing for high performance analysis.
  • We consult in data architecture challenges.

Clinical Data

  • Our experience with a variety of programming languages, databases, and platforms allows us to tackle challenges in data transfer, storage, and interoperability.
  • We apply human computer interaction research principles to improve the collection of discrete data.
  • By leveraging high scale data with modern analysis and indexing techniques we can help with clinical decision support systems.

Data Visualization

  • We specialize in interactive data tools for clinicians, researchers, and policy-makers to explore a data set.
  • We use Web standards that are compatible with all browsers including Internet Explorer version 7 and above.
  • We have a background in perception research (Damien has a degree in cognitive psychology), information processing, and visualization research and best practices.

mHealth Systems

  • Mobile Health is a way to engage patients and others in health promotion throughout their daily life.
  • We use SMS text messaging and Interactive Voice Response (automated phone conversations).
  • Bidirectional conversations allow patients to be reminded of health behaviors while also giving feedback to the system.
  • mHealth systems can augment a clinical care team as part of a collaborate care model.
  • Health communication messages can be tailored to each participant based on state of readiness, beliefs, perceived norms, etc.

Mobile Interfaces

  • We develop iPhone and iPad apps for health promotion and care.
  • A mobile app is a great way to collect patient reported outcomes data.
  • We work with GIS systems to make geographically aware tools.

We also provide the service of server architectural consulting, and in systems administration. We have extensive experience designing, developing, maintaining, and hosting a variety of technologies including the following.

Supported Technologies

  • Front ends: React, React Native, Vue, CSS
  • Languages: Perl, Python, Ruby, NodeJs, Java, JavaScript, Objective C
  • Servers: Linux, Windows
  • Databases: MySQL, MondoDB, PostreSQL, MS SQL
  • Web Servers: Apache, Nginx, IIS, NodeJS
  • Hosting: Amazon Web Services, Azure


Damien Damien Leri, MPH, MS Ed
Founder and Principal Engineer

Damien started his first information technology company as a teenager and has worked professionally in information technology for 20 years. At the University of Pennsylvania he received a B.A. in Psychology, an MS.Ed (Education), and a Master of Public Health. He can be reached via damien at bigyellowstar.com.