Limits...
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.

Show MeSH
B-mode Pattern injection with a linear array.This picture illustrates how a single virtual pixel is injected to the B-mode image from an active echo element.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4206269&req=5

pone-0104262-g002: B-mode Pattern injection with a linear array.This picture illustrates how a single virtual pixel is injected to the B-mode image from an active echo element.

Mentions: The pattern injected into the image is not limited to the AE spot. As described previously, a B-mode image is formed by a series of A-mode lines. As shown in figure 2, suppose a B mode image is composed of 16 A-mode lines; the normal distance from the AE element to the probe is y. To generate a virtual spot on the point A, an ultrasound pulse should be received by the probe when the A-mode line #4 is being acquired, with a delay ofwhere c is the speed of sound in this medium. The ultrasound pulse is generated from the AE element at position O, the distance between O and the center of the imaging elements R is d. The time for sound to travel from O to R is ttravel = d/c. So the timing that the element should send an ultrasound pulse is:In other words, if an ultrasound pulse is fired from the AE element t seconds after the probe starts acquiring the A mode line #4, it will be shown as a virtual spot at position A 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)

B-mode Pattern injection with a linear array.This picture illustrates how a single virtual pixel is injected to the B-mode image from an active echo element.
© Copyright Policy
Related In: Results  -  Collection

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

pone-0104262-g002: B-mode Pattern injection with a linear array.This picture illustrates how a single virtual pixel is injected to the B-mode image from an active echo element.
Mentions: The pattern injected into the image is not limited to the AE spot. As described previously, a B-mode image is formed by a series of A-mode lines. As shown in figure 2, suppose a B mode image is composed of 16 A-mode lines; the normal distance from the AE element to the probe is y. To generate a virtual spot on the point A, an ultrasound pulse should be received by the probe when the A-mode line #4 is being acquired, with a delay ofwhere c is the speed of sound in this medium. The ultrasound pulse is generated from the AE element at position O, the distance between O and the center of the imaging elements R is d. The time for sound to travel from O to R is ttravel = d/c. So the timing that the element should send an ultrasound pulse is:In other words, if an ultrasound pulse is fired from the AE element t seconds after the probe starts acquiring the A mode line #4, it will be shown as a virtual spot at position A 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