Surgery – Diagnostic testing – Detecting nuclear – electromagnetic – or ultrasonic radiation
Reexamination Certificate
2000-06-02
2001-10-23
Jaworski, Francis J. (Department: 3737)
Surgery
Diagnostic testing
Detecting nuclear, electromagnetic, or ultrasonic radiation
C600S467000
Reexamination Certificate
active
06306096
ABSTRACT:
BACKGROUND OF THE INVENTION
Noninvasive ultrasonic imaging systems are widely used for performing ultrasonic imaging and taking measurements. Such systems typically use scan heads which are placed against a patients skin. Exemplary uses for such systems include heart and internal organ examinations as well as examinations of developing fetuses. These systems operate by transmitting ultrasonic waves into the body, receiving echoes returned from tissue interfaces upon which the waves impinge, and translating the received echo information into a structural representation of the planar slice of the body through which the ultrasonic waves are directed.
Catheter based invasive ultrasound imaging systems, typically used for intracardiac or transvascular imaging, are a relatively new addition to ultrasound armamentarian. Conventional underfluid transducers for use on catheters are comprised of crystal arrays (e.g. linear phased array) or a single crystal translated over a surface, producing a tomographic field of view in an azimuthal plane of the array. Typical arrays include: 1) linear array (linear sequential array), usually producing a rectangular or rhomboidal picture; 2) cylindrical array or rotating crystal, producing a round pie-shaped tomographic cut of structures; and 3) sector array (linear phased array), producing a triangular shaped image emanating from a small transducer source. All images are tomographic in nature and are focused in the azimuthal and elevation plane. The intent of having these conventional transducer configurations is to produce a thin ultrasound cut of the insonated structures. Such tomographic planes by nature are thin and of high resolution.
The narrow field of view provided by conventional catheter transducer configurations is problematic because structures lying outside of the plane of view can only be visualized by reorienting or manipulating the catheter. Due to the tortuous and confined nature of a typical catheter pathway, catheter manipulation is impractical and often impossible. Consequently, the localization of specific targets is difficult and at times can be disorienting because of an inability to appreciate contiguous anatomic landmarks.
Advances in 3-dimensional imaging capabilities have been made with respect to non-catheter related ultrasonic imaging systems. For example, U.S. Pat. No. 5,305,756, issued to Entrekin et al., which is hereby incorporated by reference, discloses general 3-dimensional imaging techniques in a non-catheter based context. What is needed is a catheter based imaging system that utilizes 3-dimensional imaging techniques to provide a wide field of view so as to improve anatomic localization for precision underfluid diagnostics and interventions.
SUMMARY OF THE INVENTION
The present invention relates generally to a volumetric, 3-dimensional image ultrasound transducer underfluid catheter system.
The present invention also relates to an ultrasonic and interventional catheter device operated in an intracardiac or transvascular system, with the aid of a volumetric 3-dimensional imaging capability.
In one particular embodiment, the present invention relates to a catheter apparatus comprising an underfluid catheter body having proximal and distal ends. An ultrasonic transducer array is mounted longitudinally along the catheter body proximate the distal end. The transducer array has a volumetric field of view that projects radially/laterally outward from the catheter. Features in such wide volumetric field of view can be imaged, measured, or intervened by an underfluid therapeutic device with an aid of the real-time image.
It is significant that the transducer array described in the previous paragraph has a 3-dimensional field of view. A first dimension; referred to as an azimuthal direction, is aligned with the length of the transducer array. A second dimension, referred to as a depth direction, is the depth into the body which an ultrasonic signal is transmitted and from which an echo return. A third dimension, referred to as an elevation direction, is perpendicular to both the azimuthal and the depth directions.
If the transducer array comprises a linear phased array having a single row of piezoelectric crystals, a 3-dimensional field of view can be generated by focusing the ultrasound signals in the azimuthal direction (parallel to the longitudinal axis of the catheter) and diverging the ultrasound signals in the elevational direction (transverse to the longitudinal axis of the catheter). The ultrasonic signals can be diverged in the elevational direction through the use of lenses. For example, the signals can be diverged by mounting a silicone rubber concave lens or a plastic convex lens in front of the transducer array.
If the transducer array comprises multiple rows of piezoelectric crystals, a 3-dimensional field of view can be generated by electronically phasing the ultrasound signals in both the azimuthal and elevational directions. Of course, lenses can be used in association with multiple row arrays to further widen the field of view.
It will be appreciated that catheters constructed in accordance with the principles of the present invention can optionally include one or more ports that extend longitudinally through the catheter bodies. The ports are preferably adapted for guiding therapeutic instruments through the catheter and preferably have exit ends adjacent to the field of view of the catheter imaging system. In operation, the ports guide the therapeutic instruments such that the operative ends of a therapeutic instruments are directed toward the 3-dimensional field of view of the imaging system.
It will also be appreciated that catheters constructed in accordance with the principles of the present invention can include one or more guidewire ports which extend longitudinally through the catheters and are adapted for receiving guidewires.
One advantage of the present invention is to provide real-time 3-dimensional images of underfluid features so as to visualize contiguous anatomy, such as a large volume of tissues without frequently rotating, flexing, or extending the catheter.
Another advantage is that the present invention provides a much better underfluid “eye”—a 3-dimensional “motion picture”—for an operator when he/she intervenes the underfluid features by using an underfluid therapeutic device. These images provide the operator a direct aid without opening a large area of a body.
A further advantage is that the present invention have numerous clinical applications. One is related to underfluid imaging: There is a considerable need to increase the field of view when imaging from within chambers or blood vessels. The physical space of the chambers or blood vessels is small, and the anatomy in question is closed approximated and usually totally surrounds the transducer. A conventional tomographic presentation provides only a limited slice, thus requiring frequent manipulation of transducer in order to visualize contiguous anatomy. The present invention is a solution to visualizing larger volumes of tissue. The underfluid defocusing transducer array does not appreciably affect the electronics and does not require alteration in the display format. The catheter apparatus is immersed in fluid, a homogeneous, low scattering medium, which is an ideal environment for this particular transducer modification.
Another main clinical application is related to underfluid intervention: In diagnostic and therapeutic procedures, there is an increasing need for volumetric 3-dimensional visualization which would improve anatomic localization and recognition of continuous structures and events.
A further advantage of the present invention is that by using such a catheter system, major surgical procedures can be avoided. It dramatically reduces the patient's physical pain in operation and mental distress after operation due to any large visible scars, etc.
These and various other advantages and features of novelty which characterize the invention are pointed out with particularity in the claims annexed hereto and f
Seward James Bernard
Tajik Abdul Jamil
Jaworski Francis J.
Mayo Foundation for Medical Education and Research
Merchant & Gould P.C.
LandOfFree
Volumetric image ultrasound transducer underfluid catheter... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Volumetric image ultrasound transducer underfluid catheter..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Volumetric image ultrasound transducer underfluid catheter... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2567971