SwRI IRD 2003--Development of a Networked Blood Pressure Monitoring System, 10-9369

Background - Healthcare costs are expected to increase at double-digit rates in the coming years. Cardiovascular disease is the primary cause of death of males in the U.S. and consumes a large share of these healthcare dollars. Hypertension, also called high blood pressure, most commonly is the result of a narrowing or stiffening of the arteries. If untreated, hypertension can lead to heart attack or even death. If detected early, hypertension can often be reversed through diet, exercise, and pharmaceuticals. This reduces the likelihood of catastrophic disease, hospitalization, and death.

Approach - The objective of this project is to develop and implement a networked environment at the Institute to monitor the arterial health of SwRI employees. The goal of this implementation is to investigate improving employee health and to establish an Institute capability for networking medical devices using the Internet.

The general approach was to network-enable an existing automated blood pressure measurement device (Colin BP-203RV II) to automatically save blood pressure measurements in an online database. The system was developed using open source software components.

Accomplishments - A blood pressure measurement station was designed that consisted of a Colin blood pressure measurement device and a control computer. A parallel port-controlled switch circuit was added to the Colin device to prevent unauthorized use of the system. When a user logs into the web interface, a custom-written LabVIEWTM program running on the control computer identifies the successful login and activates the switch, thus enabling the blood pressure device. Blood pressure measurements are sent from the Colin device to the control computer via a serial port connection. The LabVIEW program automatically stores the obtained blood pressure measurements on the project database server. The project server was developed using open source software components and consists of Intel-based hardware running the Linux operation system (RedHat 7.3), the Apache web server (1.3.28), and the MySQL database server (4.0.15).

A web-based portal interface to the database and other blood pressure reference material was developed using the Geeklog (http://www.geeklog.net) open-source software package. The portal allows subjects to review their history of blood pressure measurements in tabular and graphical format. In addition, the portal allows subjects to manually keep a history of their weight that is viewable in tabular format.
A total of eight blood pressure measurement stations have been installed on the SwRI campus. As of December 15, 2003, a total of 109 subjects have been enrolled in the study and a total of 1634 blood pressure measurements have been obtained.

The Blood Pressure Measurement Station. The control computer is on the left. The Colin blood pressure measurement device is on the right. The display is showing the last five blood pressure values obtained.

Web-based user interface portal displaying blood pressure values recorded over the past quarter. The graph order is systolic pressure, diastolic pressure, and pulse rate from top to bottom. The blue line in the graphs indicates the blood pressure trend for the displayed data (the purple squares). The color bands in the graph correspond to the blood pressure classifications contained in the JNC 7 report released in May 2003.