Surgery – Diagnostic testing – Detecting nuclear – electromagnetic – or ultrasonic radiation
Reexamination Certificate
2000-10-31
2003-02-11
Lateef, Marvin M. (Department: 3737)
Surgery
Diagnostic testing
Detecting nuclear, electromagnetic, or ultrasonic radiation
Reexamination Certificate
active
06517491
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to an integrated spatial sensor and transducer, and in particular to a housing combining a transducer and spatial sensor.
Ultrasound has become a popular technique for the imaging and measuring of internal organs and anatomy. Ultrasound has several advantages over MRI and CT scanning: ultrasound is real-time, non-invasive, non-radiative, and relatively less expensive to buy and maintain compared to MRI and CT equipment. As with most medical technology, ultrasound systems are evolving to take advantage of new technologies and in response to the ever-increasing demands of medical professionals. One of the most requested features on ultrasound systems is the ability to present an image having the appearance of 3-D. Such an image is produced from a 3-D matrix of data. Generally, three dimensional data is presented in one of two forms: a surface scanned structure or a volume scanned structure. Either structure is formed by isonifying a volume and rendering the data to produce a 2-D image showing a 3-D object (referred to herein as a 3-D image).
Currently, there are two different methods for obtaining scan data in preparation for rendering a 3-D surface. The first method involves the use of a 1-D transducer which typically uses a linear array of elements to produce a 1-D slice of data. Alternatively, a single element transducer can be mechanically oscillated. After each slice is obtained, the sonographer (or more generically “user”) moves the transducer to obtain another slice. Software is then used to stitch together a volume data set.
The second method involves the use of a two-dimensional transducer array to isonify a volume. In this method, two broad categories exist. Some systems use a so-called 1.5-D array, which comprises several rows of elements. A 1.5-D array can be conceptually thought of as a stack of convention 1-D arrays, each independently steerable along the azimuth. A 1.5-D array is not steerable in the elevation direction. A true 2-D array is a matrix of elements (and is sometimes referred to as a “matrix array”) which acts as a unified whole and is steerable in the elevation direction. True 2-D array transducers are believed to be capable of producing a three dimensional volume of data without requiring significant operator involvement. At the present time, true 2-D transducers are largely experimental and very expensive, but the results have exceeded expectations. However, it has been determined that the response of tissue structures perpendicular to the face of the 2-D array is attenuated, such that some of the image produced by echoes off of such tissue structures is faint or nonexistent.
For the present, the first method of obtaining a plurality of data slices and stitching them together to form a volume data set is the preferred method of obtaining a 3-D image.
Freehand imaging is a method to develop 3-D images in which the sonographer moves a 1-D array across a patient “freehand” and a specialized graphic processor attempts to warp together a 3-D image. One innovation that has greatly improved the image quality of 3-D images produced using the freehand method is the use location sensors externally mounted on a 1-D ultrasound transducer to register the spatial location and orientation with respect to translation and angulation of acquired ultrasound images. This method is typically referred to as the calibrated freehand method. To develop 3-D images, each 2-D image pixel is mapped to a physical location in the patient's coordinate set. Data sets obtained from the scan are transformed into a Cartesian coordinate system to enable visualization similar to that provided by CTs or MRIs. Typically, a graphics workstation, such as those offered by SILICON GRAPHICS, assists with real-time visualization. Further, animation can be employed to perform rotations and zooming or to create a “cine-loop” display. Using such techniques, reconstructed 3-D images of the heart, blood vessels, stomach and other organs can be developed. Essentially, the 2-D image slices or “planes” that stand-alone ultrasound provides are “pasted” together to provide a 3-D data set which can be rendered and displayed on a 2-D monitor. The 3-D data set is amenable to interaction and manipulation, and can be shared for remote consults via download or stored digitally.
Ascension Technology Corporation produces several models of magnetic location sensors under their FLOCK OF BIRDS™ line that are suitable for use with the calibrated freehand method. For example, the DC-pulsed magnetically tracked mini-sensor (18 mm×8 mm×8 mm) of the miniBIRD™ system measures 6 degrees of freedom when mounted on an ultrasound probe and are suitable for internal or external anatomical explorations. The pcBIRD™ is a 6 degree of freedom tracker on a PC card that dedicates a separate processor for each receiver. It measures the location and orientation of a small receiver referenced to a magnetic transmitter. The electronics board plugs into the ISA slot of any PC computer.
FIG. 1
is a block diagram of a known ultrasound imaging system
100
configured for freehand scanning. An ultrasound unit
110
generally comprises a housing (such as a cart) supporting an imaging unit that includes transmission and reception circuits (including for example a beamformer) along with an image processing unit including display circuits. A transducer
112
, connected to the ultrasound unit
110
, outputs and receives ultrasound signals under the control of the imaging unit so as to scan a patient
114
in a known manner.
The ultrasound imaging system
100
is configured for use with the miniBIRD system from ASCENSION TECHNOLOGY CORPORATION. Like all known freehand imaging systems, Ascension Technologies' applications call for the external attachment of a sensor to a transducer. A transmitter
116
is positioned in the vicinity of the patient
114
, typically in connection with a bed or table upon which the patient
114
rests. A receiver
118
, affixed to the surface of the transducer
112
, receives a pulsed DC magnetic field transmitted by the transmitter
116
. From measured magnetic field characteristics, the receiver
118
computes its location and orientation and makes this information available to a host computer
120
via a controller
122
. The controller
122
synchronizes operation of the transmitter
116
and receiver
112
under the direction of the host computer
120
.
The host computer
120
is also in communication with the ultrasound unit
110
. The host computer
120
, using location information from the receiver
118
and ultrasound image data from the ultrasound unit
110
, tags individual frames of ultrasound image data with location information and “stitches” together the various frames, using known algorithms, to produce 3-D images. For example, EchoTech 3-D Imaging Systems Inc. of Lafayette, Colo. produces systems that are capable of interfacing with the miniBIRD system and various ultrasound systems to produce real-time (or more accurately near real-time) 3-D images.
Systems similar to the one shown in
FIG. 1
have several drawbacks. The first, and perhaps the most dangerous, is that such systems require a number of separate devices and a plurality of cables to connect the devices. For example, the transducer
112
has two cables extending therefrom, one going to the controller
122
and one going to the ultrasound unit
110
. Additionally, the controller
122
, transmitter
116
and host computer
120
all have various cables extending therefrom. In the already crowded medical environment, such clutter can lead to disaster, torn cables, shattered equipment, and perhaps even injury to the patient or attending professionals. A second problem arises due to the external attachment of the receiver
118
, that of indeterminate calibration. Each time the receiver
118
is re-attached to the transducer
112
, a calibration procedure should be initiated to determine the orientation between the transducer
112
and receiver
118
. This orientat
Chang Showna Hsu-Hwa
Thiele Karl E
Imam Ali M.
Koninklijke Philips Electronics N.V
Lateef Marvin M.
LandOfFree
Transducer with spatial sensor does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Transducer with spatial sensor, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Transducer with spatial sensor will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3158187