Surgery – Diagnostic testing – Detecting nuclear – electromagnetic – or ultrasonic radiation
Reexamination Certificate
1999-03-23
2004-09-07
Smith, Ruth S. (Department: 3737)
Surgery
Diagnostic testing
Detecting nuclear, electromagnetic, or ultrasonic radiation
C600S374000, C600S509000, C607S089000, C606S014000, C606S015000
Reexamination Certificate
active
06788967
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to medical diagnosis, treatment and imaging systems. More particularly, the present invention relates to medical probes whose location can be detected and adjusted and which have an additional detection, imaging and/or treatment function.
BACKGROUND OF THE INVENTION
Probes, such as catheters, suitable for various medical procedures and internal imaging, are fairly common. Such probes include: balloon angioplasty, catheters, catheters with laser-, electrical- or cryo-ablation characteristics, catheters having ultrasound imaging heads, probes used for nearly incisionless-surgery or diagnosis, and endoscopes. Where such probes are used for treatment, the probes must be carefully positioned in relation to the body structure. Even for imaging systems such as ultrasound systems, some positioning capability has been described.
In cardiovascular examinations and in particular in those using invasive techniques, multiple catheters are inserted into the vascular system and then advanced towards the cardiac chambers. The procedure itself is generally performed under fluoroscope guidance which necessitates the use of a continuous source of x-ray as a transillumination source. The image generated using the fluoroscope is a 2D display of the anatomy with the location of the catheter superimposed. The anatomy can be viewed with a relatively low resolution since the cardiac chamber and the blood vessels are transparent to the x-ray radiation.
More recently, several technologies have been developed to ease the process of cardiac catheterization, mainly by enabling the physician to follow the path of the tip of the catheter inside the blood vessel. Some of this technology is based on digital subtraction radiography technology that enables viewing the blood vessel after the injection of a radio contrast dye and superimposing on that image the path of the catheter. These technologies necessitate the use of radiopaque dyes which are a major cause of morbidity in high-risk patients during cardiac catheterization.
U.S. Pat. No. 5,042,486 to Pfeiller et al., the disclosure of which is incorporated herein by reference, describes a method in which the position of a catheter tip is located using electromagnetic fields. The catheter is introduced and the tip location is followed. The path of the tip is superimposed on the pre-registered image of the blood vessel or the organ, through which the catheter was advanced. However, this technology requires acquisition and processing of images prior to the procedure and involves a highly sophisticated and time-consuming procedure for the correct alignment of the image acquired previous to this procedure, and the orientation and location of the blood vessel or the organ during the catheterization procedure itself.
U.S. Pat. No. 4,821,731 to Martinelli et al., the disclosure of which is incorporated herein by reference, discloses a method for internal imaging of a living body using ultrasound. In this patent the position of an ultrasound imaging catheter is determined by computing the relative position of the catheter using the response of an ultrasound transducer to a reference signal, and by computing the angular orientation of the catheter about its axis by determining the signal induced in a single coil by substantially perpendicular magnetic fields of different frequencies. The ultrasound transducer is also used to send and detect ultrasound signals in a direction perpendicular to the catheter axis. By rotating the catheter and moving it along its axis an ultrasound image may be generated. The catheter is also described as being capable of transmitting a laser beam to the end thereof to ablate tissue from lesions on the walls of arteries.
A catheter which can be located in a patient using an ultrasound transmitter located in the catheter, is disclosed in U.S. Pat. No. 4,697,595 and in the technical note “Ultrasonically Marked Catheter, a Method for Positive Echographic Catheter Position and Identification”, Bryer et al., Medical and Biological Engineering and Computing, May, 1985, pages 268-271. Also, U.S. Pat. No. 5,042,486 discloses a catheter which can be located in patients using non-ionizing fields and suitably imposing catheter location on a previously obtained radiological image of the blood vessel.
PCT Patent Publication WO 94/0938, the disclosure of which is incorporated herein by reference, describes a system using a single-coil type sensor which is coaxial with the long axis of a catheter and which senses fields which are generated by three multicoil generators external to the body of a patient.
Other methods and apparatus for the determination of the position of a catheter or endoscope are shown in U.S. Pat. Nos. 5,253,647; 5,057,095; 4,095,698; 5,318,025; 5,271,400; 5,211,165; 5,265,610; 5,255,680; 5,251,635 and 5,265,611.
U.S. Pat. No. 3,644,825 describes a system which uses the relative motion of a sensor in the determination of its position. The relative motion supplies information to the sensing coils needed to identify position and orientation. However, such a solution is not applicable to identifying position and location of the object where there is no relative motion between the object and the reference frame.
U.S. Pat. No. 3,868,565, the disclosure of which is incorporated herein by reference, comprises a tracking system for continuously determining the relative position and orientation of a remote object. This tracking system includes orthogonally positioned loops for both a plurality of sensors and a plurality of radiating antennas. With the proper excitation currents to those loops, the radiating antennas generate an electromagnetic field that is radiated from those antennas to the sensor. The tracking system operates as a closed loop system where a controlling means measures the field that is received at the sensor at the remote object and feeds the information back to radiating antennas to provide a nutating field radiating as a pointing vector towards the remote object. Accordingly, the pointing vector gives the direction to the sensing antenna from the radiating antenna.
Similarly, Kuipers describes in his U.S. Pat. No. 4,017,858, the disclosure of which is incorporated herein by reference, an electromagnetic field which rotates about a pointing vector and is used both to track or locate the remote object in addition to determining the relative orientation of the object. This system, wherein the radiating coils are charged with the properly designed wave forms, generates a magnetic field which, in a closed loop manner, can be fed into processing means to generate the information needed to determine an orientation of a remote object.
U.S. Pat. No. 4,054,881, the disclosure of which is incorporated herein by reference, describes a non-tracking system for determining the position and location of a remote object with respect to a reference frame. This is accomplished by applying electrical signals to each of three mutually-orthogonal, radiating antennas, the electrical signals being multiplexed with respect to each other and containing information characterizing the polarity and magnetic moment of the radiated electromagnetic fields. The radiated fields are detected and measured by the three mutually orthogonal receiving antennas having a known relationship to the remote object, which produce nine parameters. These nine parameters, in combination with one known position or orientation parameter, are sufficient to determine the position and orientation parameters of the receiving antennas with respect to the position and orientation of the radiating antennas.
U.S. Pat. No. 4,849,692, the disclosure of which is incorporated herein by reference, describes a quantitative method for measuring the relative position and orientation of two bodies in the presence of metals. Measuring the position and orientation of receiving antennas with respect to the transmitting antennas is achieved using direct current electromagnetic field signals. Electromagnetic radiation is designed to be transmitt
Ben-Haim Shlomo
Greenberg Ilan
Osadchy Daniel
Peless Udi
Biosense Inc.
Capezzuto Louis J.
Smith Ruth S.
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