ProtoLink was asked by a manufacturer of medical infusion pumps to architect a system to collect status information transmitted wirelessly by their pumps, and to make that data available to both end users and other software systems within a medical facility.
To achieve the desired objectives, ProtoLink designed and developed a system comprised of a relational database, a Data Collection Application, and a browser-based Configuration and Reporting Application. In addition, several interface engines were developed to facilitate interoperability with other healthcare systems using messaging standards established by the Health Level Seven (HL7) organization.
The relational database was implemented using Microsoft SQL Server. It consists of a set of database tables (and associated stored procedures, views, and triggers) for storing the data received from the pumps.
Data Collection Application was written in C# and runs as a Windows Service. It uses TCP/IP sockets to monitor a wireless LAN for data being transmitted by the pumps and then logs the received data to the database using ADO.NET. If the database is inaccessible, the application buffers the data to a local file until the database becomes available, at which time the data is automatically transferred from the file to the database. The Data Collection Application is also responsible for periodically initiating database maintenance tasks, such as creating backups and purging old data.
The Configuration and Reporting Application is an ASP.NET web application written in C# and JavaScript. It is used to perform configuration tasks, such as maintaining the tables that define the pumps, users, and reports in the system. In addition, the application accesses the stored pump data and generates real-time status and historical reports, using SQL Server Reporting Services as the report generation engine.
The interface engines are implemented as Windows Services, written in C#. One of the interfaces accepts HL7 messages from Admission, Discharge, and Transfer (ADT) systems. This allows patient location information to be included in the real-time status and historical reports produced by the Configuration and Reporting Application. A second interface provides pump status and alarm information in the form of HL7 messages to hospital information systems through the use of transactions established by the Patient Care Devices (PCD) domain of the Integrating the Healthcare Enterprise (IHE) organization. A third interface accepts HL7 messages containing infusion order information from medication administration systems (also through an IHE PCD-specified transaction) and uses that information to wirelessly program a designated pump with the appropriate infusion parameters.
To aid with testing, ProtoLink also developed an application that simulates multiple pumps transmitting status messages to the Data Collection Application. The simulator is used to assess the load imposed by a particular number of pumps on a network and to identify bottlenecks that affect system performance.