Background: Opened heart surgery with cardiopulmonary bypass (CPB) is a critical and complex procedure. A Heart-Lung machine (HLM) plays an important role for controlling the cardiopulmonary functions during the time of the surgery. Perfusionist must consider a variety of essential factors and calculate several cardiovascular parameters regarding the process of operating a HLM. To improving the quality of work, personal digital assistants must continually develop their skills and knowledge levels.Objective: The goal of this work is to construct a mobile application device that has a wide variety of functions which has the capacity to control targeted clinical planning and decision making for HLM users so to enable them to have control and evaluate the mobile application to user’s satisfaction. Methods: This smartphone app was constructed base on the ionic framework. The researchers have developed an unique algorithms for operating the HLM. The app was generated according to the phase of design, algorithm, validation, and user’s satisfaction of perfusionists.Results: The Project Researchers have officially assigned this medical mobile application with the name is Perfusion Assistant app that can be accessed and used effectively cross platform on iOS and Android. The application is comprised of five main categories which includes: a perfusion calculator, myocardial protection chart, drugs details, priming solution and parameters values. Result shown that all cardiovascular parameters did not significant differ from Perfusion Assistant app when compared to manual calculation. User’s satisfaction was at 3.64±0.76 in the first evaluation. After modification with feedback from experts, the app was evaluated with a 4.13±0.56 satisfaction. Conclusions: Perfusion Assistant app is an application designed in clinical planning and decision of HLM controlling for perfusionists and medical staff that work in an opened heart surgery arena. Perfusion Assistant app offers a variety of calculations related to CPB including blood flow rate, systemic vascular resistant, priming volume, and predicted hematocrit. Furthermore, Perfusion Assistant app provides a quick, easy access, and real-time application for CPB that user’s satisfaction was a good level.