Troy K. Adebar
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Research Subjects
Troy K. Adebar has a total of 5 co-authors. Here are the top co-authors by number of shared publications:
- Allison M. Okamura
Department of Mechanical Engineering, Stanford University, Stanford, CA, USA
2 shared publications - Ashley E. Fletcher
Department of Mechanical Engineering, Stanford University, Stanford, CA, USA
1 shared publication - Joseph D. Greer
Department of Mechanical Engineering, Stanford University, Stanford, CA, USA
1 shared publication - Nina M. Jimenez
Department of Mechanical Engineering, Stanford University, Stanford, CA, USA
1 shared publication - Sarah S. Cabreros
Department of Mechanical Engineering, Stanford University, Stanford, CA, USA
1 shared publication
Latest Publications
- 1 May 2015
- Published by Institute of Electrical and Electronics Engineers (IEEE)
- Vol. 2015, 2244-2249
Remote electromagnetic vibration of steerable needles for imaging in power Doppler ultrasound
Robotic needle steering systems for minimally invasive medical procedures require complementary medical imaging systems to track the needles in real time. Ultrasound is a promising imaging modality because it offers relatively low-cost, real-time imaging of the needle. Previous methods applied vibration to the base of the needle using a voice coil actuator, in order to make the needle visible in power Doppler ultrasound. We propose a new method for needle tip vibration, using electromagnetic actuation of small permanent magnets placed inside the needle to improve needle tip visibility in power Doppler imaging. Robotic needle insertion experiments using artificial tissue and ex vivo porcine liver showed that the electromagnetic tip vibration method can generate a stronger Doppler response compared to the previous base vibration method, resulting in better imaging at greater needle depth in tissue. It also eliminates previous issues with vibration damping along the shaft of the needle.
- 1 May 2015
- Published by Institute of Electrical and Electronics Engineers (IEEE)
- Vol. 2015, 2244-2249
Remote electromagnetic vibration of steerable needles for imaging in power Doppler ultrasound
Robotic needle steering systems for minimally invasive medical procedures require complementary medical imaging systems to track the needles in real time. Ultrasound is a promising imaging modality because it offers relatively low-cost, real-time imaging of the needle. Previous methods applied vibration to the base of the needle using a voice coil actuator, in order to make the needle visible in power Doppler ultrasound. We propose a new method for needle tip vibration, using electromagnetic actuation of small permanent magnets placed inside the needle to improve needle tip visibility in power Doppler imaging. Robotic needle insertion experiments using artificial tissue and ex vivo porcine liver showed that the electromagnetic tip vibration method can generate a stronger Doppler response compared to the previous base vibration method, resulting in better imaging at greater needle depth in tissue. It also eliminates previous issues with vibration damping along the shaft of the needle.
- 1 July 2014
- Published by Institute of Electrical and Electronics Engineers (IEEE) in IEEE Transactions on Biomedical Engineering
- Vol. 61 (12) , 2899-2910
3-D Ultrasound-Guided Robotic Needle Steering in Biological Tissue
Robotic needle steering systems have the potential to greatly improve medical interventions, but they require new methods for medical image guidance. Three-dimensional (3-D) ultrasound is a widely available, low-cost imaging modality that may be used to provide real-time feedback to needle steering robots. Unfortunately, the poor visibility of steerable needles in standard grayscale ultrasound makes automatic segmentation of the needles impractical. A new imaging approach is proposed, in which high-frequency vibration of a steerable needle makes it visible in ultrasound Doppler images. Experiments demonstrate that segmentation from this Doppler data is accurate to within 1-2 mm. An image-guided control algorithm that incorporates the segmentation data as feedback is also described. In experimental tests in ex vivo bovine liver tissue, a robotic needle steering system implementing this control scheme was able to consistently steer a needle tip to a simulated target with an average error of 1.57 mm. Implementation of 3-D ultrasound-guided needle steering in biological tissue represents a significant step toward the clinical application of robotic needle steering.
- 1 July 2014
- Published by Institute of Electrical and Electronics Engineers (IEEE) in IEEE Transactions on Biomedical Engineering
- Vol. 61 (12) , 2899-2910
3-D Ultrasound-Guided Robotic Needle Steering in Biological Tissue
Robotic needle steering systems have the potential to greatly improve medical interventions, but they require new methods for medical image guidance. Three-dimensional (3-D) ultrasound is a widely available, low-cost imaging modality that may be used to provide real-time feedback to needle steering robots. Unfortunately, the poor visibility of steerable needles in standard grayscale ultrasound makes automatic segmentation of the needles impractical. A new imaging approach is proposed, in which high-frequency vibration of a steerable needle makes it visible in ultrasound Doppler images. Experiments demonstrate that segmentation from this Doppler data is accurate to within 1-2 mm. An image-guided control algorithm that incorporates the segmentation data as feedback is also described. In experimental tests in ex vivo bovine liver tissue, a robotic needle steering system implementing this control scheme was able to consistently steer a needle tip to a simulated target with an average error of 1.57 mm. Implementation of 3-D ultrasound-guided needle steering in biological tissue represents a significant step toward the clinical application of robotic needle steering.