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open license. Please read the
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Type:
Educational Exhibit
Keywords:
Metastases, Cancer, Instrumentation, Equipment, Ablation procedures, Percutaneous, CT, Liver, Interventional non-vascular, Abdomen
Authors:
B. J. J. Abdullah1, C. H. Yeong1, A. B. KULKARNI2, P. B. Balakrishnan3; 1Kuala Lumpur/MY, 2Aurangabad/IN, 3Chennai/IN
DOI:
10.1594/ecr2014/C-1946
Findings and procedure details
Procedure Details:
Field of operation of the robotic arm
- The field of operation of the robotic arm in “X” and “Y” planes with varying orbital angulations were determined.
Positive angulation means needle angulation toward the robot while negative values means angulation away from the robot.
- The needle length was fixed at 20 cm.
- The centre of the X-axis was considered as 0.
- The cranio-caudal angulation was fixed at 0 degrees.
- The planned parameters such as needle angulation and taget depth displayed on the workstation were recorded.
- The CT couch was moved to the displayed cradle value in the workstation and the robotic arm was automatically moved to the designated position.
- The needle was then inserted into the abdominal biopsy phantom through the robotic arm.
- The maximum reach of the robotic arm in the X axis with and without orbital angulation (-10,
-35,
-45,
-90 +30 and +45 degrees) was recorded.
- The maximum depth of the target lesion at different orbital angulations was also recorded at the Y axis.
Accuracy of needle placement
- A watermelon was used to simulate the patient.
- 1-2 mm length of 0.21 mm diameter copper wire was placed inside the watermelon at predetermined depths of 55,
57 and 72 mm (figure XXX).
The copper wire was used as the target point in this study.
- Baseline CT images of the watermelon were reconstructed at 1 mm intervals and sent to the robot workstation.
- The needle paths were then planned with different orbital and cranio-caudal angulations at the robot workstation.
- Upon confirmation of the plan,
the robot was executed and the robotic arm automatically moved to the designated position.
- Needle was inserted into the watermelon through the roboitc arm.
- A CT scan was done to measure the deviation between the needle tip with the target point at X,
Y and Z axis.
Findings
Range of movement of the robotic arm
As the orbital angles increase,
the working range decreases for a fix needle length.
Increasing the needle length could potentially increase the working range.
However for craniocaudal angulation (with no orbital angulation) of the robotic arm,
there is much less loss of working range though the depth decreases.
The combined orbital and craniocaudal angulation would be restricted both by the cranio caudal range and the limitation of the needle length.The L and R sided docking are identical but are mirror each other in the working range.
Some of the maneuvers,
which can be used to increase the range of operation of the robotic arm,
is to off-center the patient to same side of the docking or add a few degrees of CC angle by moving few slices up or down or use shorter needle length.
For -90 degree angulation,
increasing the table height or move the patient away from robot would also potentially increase the range of operation of the robotic arm.