Biomedical Engineering Reference
In-Depth Information
FIGURE 8-13
Photograph of the
Jarvik-7 artificial
heart. (Courtesy
National Institutes of
Health [NIH]
archives.)
•
Day 13: The mitral valve on his heart malfunctioned, and he was taken back into
the operating room to replace the left ventricle of the artificial heart.
•
Other complications about this time were recurrent pulmonary insufficiency, sev-
eral episodes of acute renal failure, episodes of fever of unidentified cause, hem-
orrhagic complications of anticoagulation including continuously bleeding nose,
and respiratory failure requiring a tracheostomy.
•
Day 92: Diarrhea and vomiting leading to aspiration pneumonia and sepsis.
•
Day 112: Death preceded by progressive renal failure and refractory hypotension.
The autopsy revealed extensive pseudo-membranous colitis, acute tubular necrosis,
peritoneal and pleural effusion, centrilobular emphysema, and chronic bronchitis with
fibrosis and bronchiectasis. However, the Jarvik-7 was still intact and uncontaminated by
thrombosis or infection (Dutton, Preston et al., 1988; Hajar, 2005).
The Jarvik-7, shown in Figure 8-13, is made of polyurethane, polyester, plastic, and
aluminium and was designed for permanent implantation. It consists of two identical
pneumatically driven pumps that replaced the left and right ventricles of the heart.
Each of the pump sections consists of a chamber divided by a flexible multilayered
diaphragm, as shown in Figure 8-14. Direction of blood flow is controlled by tilting-
disk valves, held in place by a polycarbonate ring structure. External arterial and venous
connections are made using quick-connect cuffs. One of the innovations of the device is
the inner coating of rough material, developed by David Gernes. This coating helped the
blood to clot and coat the inside of the device, enabling a more natural blood flow. The
total weight of the device is about 800 g, and it requires 520 cm
3
of space within the thorax
(Jaron, 1990).
FIGURE 8-14
Schematic diagram
of one pump of the
Jarvik-7. [Adapted
from (Hajar 2005).]
