John Whitman

Publications (2)3.56 Total impact

• Source

  Available from: Daniel Laskowitz

  Article: The ultrasound brain helmet: feasibility study of multiple simultaneous 3D scans of cerebral vasculature.

  Stephen W Smith, Nikolas M Ivancevich, Brooks D Lindsey, John Whitman, Edward Light, Matthew Fronheiser, Heather A Nicoletto, Daniel T Laskowitz
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  ABSTRACT: We describe early stage experiments to test the feasibility of an ultrasound brain helmet to produce multiple simultaneous real-time three-dimensional (3D) scans of the cerebral vasculature from temporal and suboccipital acoustic windows of the skull. The transducer hardware and software of the Volumetrics Medical Imaging (Durham, NC, USA) real-time 3D scanner were modified to support dual 2.5 MHz matrix arrays of 256 transmit elements and 128 receive elements which produce two simultaneous 64 degrees pyramidal scans. The real-time display format consists of two coronal B-mode images merged into a 128 degrees sector, two simultaneous parasagittal images merged into a 128 degrees x 64 degrees C-mode plane and a simultaneous 64 degrees axial image. Real-time 3D color Doppler scans from a skull phantom with latex blood vessel were obtained after contrast agent injection as a proof of concept. The long-term goal is to produce real-time 3D ultrasound images of the cerebral vasculature from a portable unit capable of internet transmission thus enabling interactive 3D imaging, remote diagnosis and earlier therapeutic intervention. We are motivated by the urgency for rapid diagnosis of stroke due to the short time window of effective therapeutic intervention.
  Ultrasound in medicine & biology 11/2008; 35(2):329-38. · 2.02 Impact Factor
• Article: Autonomous surgical robotics using 3-D ultrasound guidance: feasibility study.

  John Whitman, Matthew P Fronheiser, Nikolas M Ivancevich, Stephen W Smith
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  ABSTRACT: The goal of this study was to test the feasibility of using a real-time 3D (RT3D) ultrasound scanner with a transthoracic matrix array transducer probe to guide an autonomous surgical robot. Employing a fiducial alignment mark on the transducer to orient the robot's frame of reference and using simple thresholding algorithms to segment the 3D images, we tested the accuracy of using the scanner to automatically direct a robot arm that touched two needle tips together within a water tank. RMS measurement error was 3.8% or 1.58 mm for an average path length of 41 mm. Using these same techniques, the autonomous robot also performed simulated needle biopsies of a cyst-like lesion in a tissue phantom. This feasibility study shows the potential for 3D ultrasound guidance of an autonomous surgical robot for simple interventional tasks, including lesion biopsy and foreign body removal.
  Ultrasonic Imaging 11/2007; 29(4):213-9. · 1.54 Impact Factor