Biomedical Engineering Reference
In-Depth Information
Pressure-Volume Relationship'' (ESPVR) describes the
line of best fit through the peak-ratio (maximum pressure
with respect to minimum volume) coordinates from
a series of pressure-volume loops generated under varying
loading conditions. The slope of this line has been shown
to be a sensitive index of myocardial contractility that is
independent of loading conditions. In addition, several
other analyses, including time-varying elastance (Emax)
and stroke work, are calculated. Time-varying elastance is
measured by determining the maximum slope of a re-
gression line through a series of isochronic pressure-
volume coordinates. Stroke work is calculated by
quantifying the area of each pressure-volume loop.
Statistical parameters are also calculated and displayed
for each set of data.
Figure 5.5-28
illustrates the
pressure-dimension loops and each of the calculated
parameters along with the various analysis options.
Finally, the user has the ability to export data sets into
spreadsheet and database files, and to export graphs
and indicators into third-party presentation software
packages, such as Microsoft PowerPoint.
information-management solutions. As the health care
industry continues to respond to the growing trends of
managed care and capitation, it is imperative for clinically
useful, cost-effective technologies to be developed and
utilized. As application needs surely will continue to
change, VI systems will continue to offer users flexible
and powerful solutions without requiring new equipment
or traditional instruments.
Virtual instruments and executive dashboards allow
organizations to effectively harness the power of the PC
to access, analyze, and share information throughout the
enterprise. The case studies discussed in this article il-
lustrate ways in which various institutions have con-
ceived and developed ''user-defined'' solutions to meet
specific requirements within the health care and in-
surance industries. These dashboards support general
operations, help hospitals manage fluctuating patient
census and bed availability, and empower clinicians and
researchers with tools to acquire, analyze, and display
clinical information from disparate sources. Decision-
makers can easily move from big-picture analyses to
transaction-level details while at the same time safely
sharing this information throughout the enterprise to
derive knowledge and to make timely, data driven de-
cisions. Collectively, these integrated applications directly
benefit health care providers, payers, and, most impor-
tantly, patients.
Summary
VI allows the development and implementation of in-
novative and cost-effective biomedical applications and
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