Introduction
Meditech internal architecture is built by a network of Raspberry PI devices specialised to manage some acquisition probes producing several kind of data. The information of the running system should be shared with the devices and collected for the graphical representation and for historical purposes so the ideal data collector is represented by a centralised database hosted on the main unit RPI master (Raspberry PI 2).
To efficiently organise the data the acquired information are stored and accessed on a MySQL database. This is one of the reasons why the RPI master is equipped with a 120Gb SSD storage.
Database organisation
The following scheme shows the central role of the RPI master database in the data collection, storage and distribution.
The MySQL database inside the Meditech architecture represent the main data center. Installed on the same RPI master unit there is also the Apache2 web server and PHP server. The database is also used for store single-record tables with the persistent configuration data of the system.
The data sets that should be available from remote can be accessed through a set of PHP APIs; this strategy permit to access from remote the real time information (for external support and assistance) using any Internet-connected device including smartphones and tablets, PC and laptop with a connected browser.
As all the Meditech units are connected on the same LAN the data exchange is fast as the MySQL server on the RPI master is accessed by the other units directly via SQL queries using SSH tunnels.