With the widespread adoption of IoT devices and solutions, their security at various levels has become an important concern of professionals and researchers. This issue takes more risk, especially with the IoT variants, IIoT (Industrial IoT) and MIoT (Medical IoT). Many existing security solutions are adapted and proposed for addressing IoT security. In this paper, we are interested in exploring blockchain technology and studying its applicability for MIoT devices. Blockchain technology provides a decentralized, autonomous, trustless, and distributed environment; it is a robust candidate for reinforcing the existing security. Whereas it should be deployed smartly to avoid its practical drawbacks related to energy-consuming and excessive computing. This is well done with a hybrid infrastructure combining IT and IoT networks. As proof of work, we start as a first phase of an ongoing project to implement our blockchain on a distributed virtual environment, including 5 virtual machines running RaspberryPI OS. RaspberryPI OS, distributed by Raspberry Pi Foundation, is based on the Debian Linux distribution, and well optimized for the use on the compact single-boards Raspberry Pi with ARM CPUs. As a blockchain platform, we opt for the use of the open source private blockchain framework, Hyperledger Fabric (HF). As feedback from this investigation, including literature review of recent works and our implementation, we confirm the meaningful contribution of blockchain for enhancing the security of MIoT devices, but this should be reinforced by other security solutions to fulfill the requirements of Zero Trust Architecture.