Biomedical Engineering Reference
In-Depth Information
Dura Substitute Materials
After the dura has been surgically modified, its closure could
be challenging. The following materials could be considered:
Electromyographic (EMG) Electrodes
Noncoated or Teflon-coated wires are placed on or in select
muscles percutaneously (temporary) or attached surgically
(chronic) for the purpose of electromyographic recording.
The electromyogram represents the combined electrical
activity produced by multiple action potentials that are
generated by contracting muscle fibers. An aseptic
approach is critical for prolonged functionality of the
chronic devices.
Bovine Pericardium
A loose, fibrous structure with excellent handling proper-
ties and tissue compatibility; it needs to be rehydrated in
sterile saline or other isotonic solutions.
Neuro-Patch
Synthetic Dura Substitute
A biostable, elastic, and flexible substitute with excellent
tissue compatibility that permits easy cutting, modeling,
and suturing.
Chronic Venous/arterial Indwelling Devices
and EKG Leads
Tubing is placed in select blood vessels for easy, quick, and
constant access to the host's vascular system for the
purpose of continuous or intermittent hemodynamic
monitoring, drug and fluid infusion, and blood sampling in
awake animals (
Cramer et al.,1994
). It is utilized in trans-
plantation and diabetes research, intravenous shunts, and
pharmacokinetic and reproductive studies, and typically
requires the use of the jacket/tether/swivel system and
modified cages. Each animal must be acclimated to wearing
a jacket. Vascular cannulae (e.g. Hickman
or Broviac
catheters) and/or EKG leads are placed and anchored
surgically, then tunneled subcutaneously to the inter-
scapular area, then externalized and led through the tether
connected to the jacket and to the swivel attached to the
custom modified cage (for more details see Chapter 16).
This system does not restrict the animal's movement and
the swivel prevents the kinking of vascular cannulae and
can function for weeks to months. The cannulae are typi-
cally connected to a multi-port infusion pump to deliver
antibiotics,
Gortex Plastic
Gortex plastic is a synthetic, bioimplantable material.
Autologus Muscle Fascia
A small piece of the temporal or the masseter muscle fascia
that can be used for autografting.
Cranial Recording Chambers
Stainless steel, titanium, ceramic or Cilux cylinders that are
attached to the cranium with a combination of screws,
methacrylate, or holding rings. A craniotomy inside the
chamber permits immediate and constant access to the
cortex through electrodes inserted for the purpose of
recording neuronal activity. The chambers are typically
covered with a lid and, while using aseptic cleaning
procedures, these devices can be maintained without
infections and used for months to years (
Figure 14.11
).
therapeutic or
studied agents, or
simply
(A)
(B)
FIGURE 14.11
Recording chamber placement. (A) Surgeon verifying future location of a chamber using precise coordinates (center
e
reflected
skin and muscles, exposed bones). (B) Two chronic, Cilux recording chambers in process of attachment to the cranium (center
e
screws in the cranium to
anchor methacrylate deposits).
