We have developed an image-guided navigation system using electromagnetically-tracked tools, with potential
applications for abdominal procedures such as biopsies, radiofrequency ablations, and radioactive seed placements. We
present the results of two phantom studies using our navigation system in a clinical environment. In the first study, a
physician and medical resident performed a total of 18 targeting passes in the abdomen of an anthropomorphic phantom
based solely upon image guidance. The distance between the target and needle tip location was measured based on
confirmatory scans which gave an average of 3.56 mm. In the second study, three foam nodules were placed at different
depths in a gelatin phantom. Ten targeting passes were attempted in each of the three depths. Final distances between the
target and needle tip were measured which gave an average of 3.00 mm. In addition to these targeting studies, we discuss
our refinement to the standard four-quadrant image-guided navigation user interface, based on clinician preferences. We
believe these refinements increase the usability of our system while decreasing targeting error.
Minimally invasive procedures are increasingly attractive to patients and medical personnel because they can reduce
operative trauma, recovery times, and overall costs. However, during these procedures, the physician has a very limited
view of the interventional field and the exact position of surgical instruments. We present an image-guided platform for
precision placement of surgical instruments based upon a small four degree-of-freedom robot (B-RobII; ARC
Seibersdorf Research GmbH, Vienna, Austria). This platform includes a custom instrument guide with an integrated
spiral fiducial pattern as the robot's end-effector, and it uses intra-operative computed tomography (CT) to register the
robot to the patient directly before the intervention. The physician can then use a graphical user interface (GUI) to select
a path for percutaneous access, and the robot will automatically align the instrument guide along this path. Potential
anatomical targets include the liver, kidney, prostate, and spine. This paper describes the robotic platform, workflow,
software, and algorithms used by the system. To demonstrate the algorithmic accuracy and suitability of the custom
instrument guide, we also present results from experiments as well as estimates of the maximum error between target
and instrument tip.
The development of image-guided interventions requires validation studies to evaluate
new protocols. So far, these validation studies have been limited to animal models and to
software and physical phantoms that simulate respiratory motion but cannot
accommodate needle punctures in a realistic manner. We have built a computer-controlled
pump that drives an anthropomorphic respiratory phantom for simulating
natural breathing patterns. This pump consists of a power supply, a motion controller
with servo amplifier, linear actuator, and custom fabricated pump assembly. By
generating several sample waveforms, we were able to simulate typical breathing
patterns. Using this pump, we were able to produce chest wall movements similar to
typical chest wall movements observed in humans. This system has potential applications
for evaluating new respiratory compensation algorithms and may facilitate improved
testing of image-guided protocols under realistic interventional conditions.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.