The Situation
Marquette's extensive product offerings include a line of noninvasive cardiac diagnostic systems. The MARS^® (Multi-parameter Arrhythmia Review Station) 8000 unity workstation is a sophisticated patient monitoring system that combines Marquette's innovative electrocardiogram (ECG) monitoring technology with the processing power of a Sun Microsystems workstation operating on the UNIX platform. The MARS 8000 records a patient's heartbeat signals for 24 to 48 hours to check for any irregularities. After all the data has been collected, it must be analyzed and presented in a way that enables ECG technicians to easily scan the recordings and catch all relevant data. From these key data points, the technicians create a thorough and accurate ECG report to be reviewed by the patient's doctor.

The Challenge
An adult human heart beats approximately 100,000 times each day, so the amount of data captured when monitoring a person's ECG for 24 hours is enormous. An average file runs around 80 Mbytes. Marquette software engineers had to create signal processing software that would "examine" each data point, determine if it was indeed an irregular heartbeat, and then present this data in a format that would aid technicians and physicians in looking at only the pertinent data (i.e., the irregular heartbeats).

Several factors complicated this signal processing analysis. The MARS 8000 system can collect inputs from a variety of different sources. For instance, the ECG signals can be captured from a battery-operated unit that the patient wears, from hospital equipment at the patient's bedside or from a hospital network. Each source has distinct characteristics that can affect the signals themselves. Even greater variations occur from patient to patient since each individual's heartbeats are somewhat unique. The software needed to be able to factor those differences into the analysis of each individual's signals.

Additionally, many other irregular signals are picked up when a patient wears a monitor. Certain movements create abnormal-looking signals that may be mistaken for irregular heartbeats. The system had to eliminate these irrelevant signals without eliminating any heartbeat data. And lastly, it was very difficult to take these massive data files and present them in a meaningful, easy-to-understand format.

Software engineers had been using self-authored tools for signal processing analysis and presentation, but as the system's level of sophistication grew, so did the need for more powerful analysis and visualization software.

The Solution
PV-WAVE from Visual Numerics delivered the powerful visualization and mathematical capabilities Marquette needed. Visual Numerics provides industry-leading, mission-critical software solutions to more than 500,000 business and technical professionals around the world. Scientists, researchers, educators, engineers, developers, intranet managers, testers and analysts use Visual Numerics' decision support tools to solve problems, identify trends and share results.

Senior software engineer Brian Young compared various analytical and visualization software packages. "Our needs had grown beyond the capabilities of our in-house software tools, so we began to research our options" says Young. "The type of signal processing we do is very sophisticated and we needed more computing power. PV-WAVE offered the most powerful visualization and graphics tools and most comprehensive mathematical libraries of any of the software we considered."

The Results
"Before we used PV-WAVE, I had to spend hours writing a C program each time I wanted to try out a new idea, and then use a separate tool to plot the data and measure the performance," Young says. "It was very frustrating and time-consuming. Now I use PV-WAVE to interactively run simulations and plot the data, and I have results in a matter of minutes instead of hours. My main objective was to find software that enables me to use my time as efficiently as possible. PV-WAVE has served me well." He adds, "My experience with Visual Numerics as a company has been very positive. I have had very few technical problems, but when I have had issues, both the Technical Support and the Sales staffs have been very responsive. At Marquette Medical Systems, we see ourselves as our customers' strategic partner in improving patient care and controlling costs through innovative diagnostic, monitoring and clinical information systems. Visual Numerics has partnered with us by providing not only the best technology, but also service that is unparalleled in the industry."