Biomedical Engineering Reference
In-Depth Information
40 mmHg. The mean arterial pressure is calculated using the equation
P
mean
=
2
P
diastolic
)/3 with the assumption that the duration in each beat to
be 2/3 diastole and 1/3 systole.
4.34 AbioCor (ABIOMED
Inc., Danvers, Massachusetts) is a totally implantable
artificial heart that shows pulsatile flow. Two polyurethane
blood pump cham-
bers with a 60-mL stroke volume produce 8 L/min
of flow. A German tourist
suffered hemodynamic stability and had to be transplanted with AbioCor BVS
5000 total heart [15]. The aircraft flew at 40,000 feet with a cabin pressure of
8,000 ft where the flow rate decreased to 4 L/m despite the set target of 5 L/m
(at the sea level) during 15.5 hours of travel. With this decrease, if power cal-
culations are performed, what is the change in efficiency? Could you explain
why the flow rate decreased?
(
P
systolic
+
4.35
A biventricular assist device (BiVAD) is one that supports both the right ven-
tricle (pumping chamber of the heart) and the left ventrical. If the frictional
factor is 30% more in the synthetic grafts and a surgeon uses three different
lengths 10 cm, 20 cm, and 30 cm long and a 16-mm graft for three different
patients, what happens to the flow rate in each case? If the pumps have to
maintain the same flow rate, how would it affect their efficiency? Use the pres-
sure values from a normal person.
References
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Verkerke, G. J., et al., “Numerical Simulation of the Pulsating Catheter Pump: A Left Ven-
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[12]
Westaby, S., et al., “Jarvik 2000 Heart: Potential for Bridge to Myocyte Recovery,”
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