# Empowering Clinical Engineering and Evidence-Based Maintenance with IoT and Indoor Navigation +
## 3 Materials and Methods  
The case study is the hospital \"Le Scotte\" in Siena (Italy), which covers 8375 rooms across 13 buildings, covering an area of 155,314 square meters, accommodating 43 departments, 220 operative units, 689 beds, and 3071 employees. The premise also includes 270,772 assets, with 44,353 of these assets identified as electro-medical equipment. The hospital serves as a reference for approximately 900,000 citizens in southeast Tuscany, accommodating more than 21,000 ordinary hospitalizations and about 3,200,000 outpatient services per year. The management of the medical equipment and its maintenance is entrusted to the Health Technology Department of the Regional Health Service Body of Tuscany (ESTAR). Dedicated internal clinical engineers and technicians take care of designing scheduled and corrective maintenance protocols according to the directives provided by manufacturers, while the maintenance actions are entrusted to an external global service provider. Work orders (WOs) on both SM and CM are stored inside the hospital CMMS.  
The Department of Medical Biotechnologies developed a computer-aided facility management (CAFM) information system, SPOT, used at the hospital \"Le Scotte\" in Siena. The web-based software is designed to meticulously map the internal organization of the hospital, including the designated purposes of various areas and performed activities, providing quantitative, qualitative, and graphical reports. It is grounded on a Microsoft SQL server DBMS (database management system) linked to other hospital databases (Figure 1). A standalone main application outlines the current state of the premises, encompassing details such as the number of beds, square meters, designated purposes, functional areas, and other pertinent information for each room.  
The main software is provided with additional modules such as a custom web search engine, a document manager, and a mobile application for indoor navigation named HiWay [24] providing two distinct navigation modes contingent on the device's actual positions: on-site and off-site. In the on-site mode, users are directed to their intended destination, the coordinates of which are retrieved via SPOT through dedicated APIs (application programming interfaces). The off-site mode is for path planning, facilitating the addition of multiple destinations to generate complex route maps, as illustrated in Figure 2. During the development of the first release of the application, the design team considered which real-time location system (RTLS) was best suited for the use-case hospital in terms of employed technologies and cost-effectiveness. The outcomes are detailed and reported in the work by [PERSON] et al. [24]. The employed RTLS, which consumes positioning information, is IndoorAtlas [29]; it utilizes multiple technologies through sensor fusion, incorporating alterations in magnetic fields, variations in WiFi and Bluetooth signals from installed routers, signals from BLE (Bluetooth Low-Energy) beacons, and position changes detected by accelerometers and gyroscopes. BLE was preferred above the other available IPS technologies because it is the de facto communication protocol for the IoT [30]. It is also the widest-used solution for IPS in hospitals [25; 26] as it provides an inexpensive solution and less critical technology in terms of electromagnetic interference (EMI) [31], allowing smooth compatibility for smartphones, tablets, and other Bluetooth-enabled devices while ensuring inexpensiveness and accuracy. The RTLS provides the coordinates of a smartphone running HiWay, allowing for real-time navigation within the hospital venue. This multifaceted approach ensures sharper and faster universal positioning, optimizing estimation timing and accuracy.  
Figure 1: A screen capture from SPOT.