Traditionally, legacy Health applications use software architecture models that make it difficult to reuse components. Reusability is an essential attribute in the software lifecycle, as it improves the quality of applications and reduces maintenance and development costs. This paper proposes the cloud tool Microservice4EHR, which dynamically generates reusable components from existing software artifacts (e.g., graphical interfaces), while conforming to the standards used in the healthcare domain. A software architecture based on Connectors and Microservice components is specified and made tangible by means of three algorithms. The use of both components is applied to a real-world scenario (a Brazilian blood donation center) and serves as an example. As a result, it is possible to notice that Health applications achieve greater reusability when they employ the microservice architecture. Thus, Microservice4EHR enables the use of reusable components in Health application architectures (for both new and legacy systems), increasing software reusability in this context.