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Active ultrasound pattern injection system (AUSPIS) for interventional tool guidance.

Guo X, Kang HJ, Etienne-Cummings R, Boctor EM - PLoS ONE (2014)

Bottom Line: Accurate tool tracking is a crucial task that directly affects the safety and effectiveness of many interventional medical procedures.Compared to CT and MRI, ultrasound-based tool tracking has many advantages, including low cost, safety, mobility and ease of use.We performed ex vitro and in vivo experiments, showing significant improvements of tool visualization and accurate localization using different US imaging platforms.

View Article: PubMed Central - PubMed

Affiliation: Dept. of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, MD, United States of America.

ABSTRACT
Accurate tool tracking is a crucial task that directly affects the safety and effectiveness of many interventional medical procedures. Compared to CT and MRI, ultrasound-based tool tracking has many advantages, including low cost, safety, mobility and ease of use. However, surgical tools are poorly visualized in conventional ultrasound images, thus preventing effective tool tracking and guidance. Existing tracking methods have not yet provided a solution that effectively solves the tool visualization and mid-plane localization accuracy problem and fully meets the clinical requirements. In this paper, we present an active ultrasound tracking and guiding system for interventional tools. The main principle of this system is to establish a bi-directional ultrasound communication between the interventional tool and US imaging machine within the tissue. This method enables the interventional tool to generate an active ultrasound field over the original imaging ultrasound signals. By controlling the timing and amplitude of the active ultrasound field, a virtual pattern can be directly injected into the US machine B mode display. In this work, we introduce the time and frequency modulation, mid-plane detection, and arbitrary pattern injection methods. The implementation of these methods further improves the target visualization and guiding accuracy, and expands the system application beyond simple tool tracking. We performed ex vitro and in vivo experiments, showing significant improvements of tool visualization and accurate localization using different US imaging platforms. An ultrasound image mid-plane detection accuracy of ±0.3 mm and a detectable tissue depth over 8.5 cm was achieved in the experiment. The system performance is tested under different configurations and system parameters. We also report the first experiment of arbitrary pattern injection to the B mode image and its application in accurate tool tracking.

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Related in: MedlinePlus

Large depth and impedance mismatching condition test result.Left: the active echo spot under 8.5 cm deep chicken breast tissue. Right: the active echo spot below a 1 inch thick aluminum plate.
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pone-0104262-g012: Large depth and impedance mismatching condition test result.Left: the active echo spot under 8.5 cm deep chicken breast tissue. Right: the active echo spot below a 1 inch thick aluminum plate.

Mentions: To further investigate the extreme functional conditions of the system, we performed two lab bench experiments. In the first one, we insert the catheter into ex vivo chicken breast tissue at 8.5 cm depth, which is close to the limit of the probe we use. This is to mimic the deep needle insertion in clinical operations. An ultrasound video is given in Video S1. In the second experiment, we placed a 1 inch thick aluminum plate in the water tank between the imaging probe and catheter to mimic the impedance of highly mismatched tissues like hard bone. As shown in figure 12, in both of the two experiments, the catheter can be effectively localized by the active echo spot. In the second test, since the speed of sound in the aluminum layer is much higher than that in water, the spot looks much closer than it actually is in the B-mode image.


Active ultrasound pattern injection system (AUSPIS) for interventional tool guidance.

Guo X, Kang HJ, Etienne-Cummings R, Boctor EM - PLoS ONE (2014)

Large depth and impedance mismatching condition test result.Left: the active echo spot under 8.5 cm deep chicken breast tissue. Right: the active echo spot below a 1 inch thick aluminum plate.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4206269&req=5

pone-0104262-g012: Large depth and impedance mismatching condition test result.Left: the active echo spot under 8.5 cm deep chicken breast tissue. Right: the active echo spot below a 1 inch thick aluminum plate.
Mentions: To further investigate the extreme functional conditions of the system, we performed two lab bench experiments. In the first one, we insert the catheter into ex vivo chicken breast tissue at 8.5 cm depth, which is close to the limit of the probe we use. This is to mimic the deep needle insertion in clinical operations. An ultrasound video is given in Video S1. In the second experiment, we placed a 1 inch thick aluminum plate in the water tank between the imaging probe and catheter to mimic the impedance of highly mismatched tissues like hard bone. As shown in figure 12, in both of the two experiments, the catheter can be effectively localized by the active echo spot. In the second test, since the speed of sound in the aluminum layer is much higher than that in water, the spot looks much closer than it actually is in the B-mode image.

Bottom Line: Accurate tool tracking is a crucial task that directly affects the safety and effectiveness of many interventional medical procedures.Compared to CT and MRI, ultrasound-based tool tracking has many advantages, including low cost, safety, mobility and ease of use.We performed ex vitro and in vivo experiments, showing significant improvements of tool visualization and accurate localization using different US imaging platforms.

View Article: PubMed Central - PubMed

Affiliation: Dept. of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, MD, United States of America.

ABSTRACT
Accurate tool tracking is a crucial task that directly affects the safety and effectiveness of many interventional medical procedures. Compared to CT and MRI, ultrasound-based tool tracking has many advantages, including low cost, safety, mobility and ease of use. However, surgical tools are poorly visualized in conventional ultrasound images, thus preventing effective tool tracking and guidance. Existing tracking methods have not yet provided a solution that effectively solves the tool visualization and mid-plane localization accuracy problem and fully meets the clinical requirements. In this paper, we present an active ultrasound tracking and guiding system for interventional tools. The main principle of this system is to establish a bi-directional ultrasound communication between the interventional tool and US imaging machine within the tissue. This method enables the interventional tool to generate an active ultrasound field over the original imaging ultrasound signals. By controlling the timing and amplitude of the active ultrasound field, a virtual pattern can be directly injected into the US machine B mode display. In this work, we introduce the time and frequency modulation, mid-plane detection, and arbitrary pattern injection methods. The implementation of these methods further improves the target visualization and guiding accuracy, and expands the system application beyond simple tool tracking. We performed ex vitro and in vivo experiments, showing significant improvements of tool visualization and accurate localization using different US imaging platforms. An ultrasound image mid-plane detection accuracy of ±0.3 mm and a detectable tissue depth over 8.5 cm was achieved in the experiment. The system performance is tested under different configurations and system parameters. We also report the first experiment of arbitrary pattern injection to the B mode image and its application in accurate tool tracking.

Show MeSH
Related in: MedlinePlus