JP2008516722A - Positioning of catheter end using tracking guide - Google Patents

Abstract

A method for determining a position of a second object that moves along a first object. The method includes determining a position for a first object; determining a linear displacement of a second object relative to the first object; and the position and the straight line of the first object. The method includes confirming the position of the second object based on the displacement.
[Selection] Figure 2

Description

RELATED APPLICATION This application is a US patent provisional application filed on October 19, 2004, entitled “Tracking a Caterer Tip by Measuring it Distance From Tracked Guide Wire Tip”, under section 119 (e) of the US Patent Act. No. 60/61998, “Usage a Caterer or Guidewire Tracking System to Provided Positional Feedback for an Automated Caterer of Guidance Navigation in the United States No. 61 / Aug. Using a Radioactive Source as th Claims the benefit of US Provisional Application No. 60/619897, filed Oct. 19, 2004, entitled “Tracked Element of a Tracking System,” the disclosures of all of which applications are incorporated herein by reference. Is done. This application is also a continuation-in-part of PCT / IL2005 / 000871 filed on August 11, 2005, entitled “Localization of a Radioactive Source with a Body of a Subject”, which is filed in 119 (e) And claims the benefit of US Provisional Application No. 60/600725, filed Aug. 12, 2004, entitled “Medical Navigation System Based on Differential Sensor”, the disclosure of which is also incorporated herein by reference. Incorporated inside.

TECHNICAL FIELD The present invention relates to locating a medical device, such as a catheter, within a body.

  There are many medical technologies that rely on the manipulation of operable instruments deep inside the body. In many cases, the instrument is inserted from the distal end (eg, a femoral vessel) and steered through the body to a target location such as a coronary artery. These techniques rely on tracking techniques to determine the position of the instrument.

  There are tracking techniques that rely on the direct establishment of the 3D position of the instrument within the body using position sensors on the instrument.

Further tracking techniques rely on establishing a map of the body part (eg, an arterial tree) and overlaying the instrument image / position on the map. For example, Lengiel et al. ( Http: www.graphics.cornell.edu/pubs/1995/LGP95.pdf , the disclosure of which is incorporated herein by reference) provides linear measurements of catheter displacement and X-rays of arteries. Teach comparison with tomographic data.

  An aspect of an embodiment of the present invention uses a determined position of a first object, and a relative linear displacement between the objects, of a second object moving along the first object. It relates to determining the location, or the path it travels. If desired, the series of positions defines a path for the first object. In an exemplary embodiment of the invention, the second object is a catheter and the first object is a catheter guide wire. If desired, the guidewire carries a tracking source at or near its end. If desired, the tracking source is a radiation source. The position is a 3D position or a 2D position, as desired.

  An aspect of certain embodiments of the invention relates to an intrabody medical system that uses machine-readable markings to determine relative linear displacements of a first object and a second object. If desired, the machine readable marking uses a binary code, such as a bar code. In an exemplary embodiment of the invention, the second object moves along the first object. In an exemplary embodiment of the invention, the system includes two objects, each marked with a machine readable marking. In an exemplary embodiment of the invention, a sensor is used on one object and a reader is used on the other object. In an exemplary embodiment of the invention, a single sensor is mounted on both objects.

According to one aspect of the present invention, a method is provided for determining a position of a second object that moves along a first object. This method
(A) determining a position for the first object;
(B) determining a linear displacement of a second object relative to the first object; and (c) based on the position of the first object and the linear displacement with respect to the first object. And confirming the position of the second object.

  Optionally, the method further includes measuring a linear displacement of the first object.

  If desired, the linear displacement of the first object and the linear displacement of the second object are each determined with respect to a specified point.

  If desired, the defined point used for the first object and the second object is a single defined point.

  Optionally, the defined points used for the first object and the second object are two separate defined points, and the method determines a linear displacement of the first object. Calculating a linear distance between a first prescribed point used for the second object and a second prescribed point used to determine a linear displacement of the second object; It further includes correcting the linear displacement value of the second object.

  Optionally, determining the position and the linear displacement for the first object is repeated to determine a series of linear displacements at a correlation position, the series of correlation positions defining a path.

  If desired, determining a linear displacement value for the second object is relative to a defined point on the first object.

  Optionally, the second object is a catheter.

  If desired, the first object is a guide wire.

  If desired, the guidewire carries a tracking source at or near its distal end.

  If desired, the tracking source is a radiation source.

  According to one aspect of the present invention, a system for performing a medical procedure is provided. The system includes at least two axially extendable members that are at least partially insertable into the body, wherein at least one of the axially extendable members is the at least two axes relative to each other. Marked with an array of machine readable markings configured to help determine relative linear displacement along a common path of directionally extendable members.

  If desired, the machine readable marking indicates a length increment.

  Optionally, the system further includes a tracking source located at a distal portion of one of the axially extendable members.

  If desired, the tracking source is a radiation source.

  If desired, the machine readable marking includes a binary code.

  Optionally, the axially extendable member includes a catheter.

  Optionally, the axially extendable member includes a catheter guide wire.

  Optionally, the catheter guidewire carries the array of machine readable markings.

According to one aspect of the present invention, a system is provided for determining a position of a first object and a second object that travel along a common path. This system
(A) a first object including a tracking source that is subject to displacement along the path;
(B) a second object subject to displacement along the first object; and (c) determining a relative displacement of the first object and the second object along the path. A displacement sensor designed and configured in such a manner.

  Optionally, the system further includes a circuit that converts the relative displacement of the first object and the second object along the path to a position of the second object.

  Optionally, the tracking source includes radioactive decay.

  If desired, the displacement sensor includes an optical sensing mechanism.

  If desired, the optical sensing mechanism reads a binary code.

  Optionally, the displacement sensor includes a mechanical sensing mechanism.

  Optionally, the first object includes a guide wire.

  Optionally, the second object includes a catheter.

According to one aspect of the present invention, a method is provided for determining a position of a second object that moves along a first object. This method
(A) determining a path along which at least one point on the first object moves;
(B) determining a linear displacement of at least one point on the second object while moving the second object along the path; and (c) on the first object. Determining the position of the selected portion of the second object by calculating a course along the path of the at least one point.

  If desired, the calculation depends on the linear displacement.

If desired, the course along the path of the first object is
(A) using a fixed known length for at least a portion of each of the first and second objects; and (b) the second object along the first object. Determined by measuring the relative displacement of the at least one point above.

  If desired, measuring the relative displacement is performed outside the subject's body.

If desired, the linear displacement is
(A) defining a reference point of the first object at a known distance from a distal end of the first object;
(B) defining a second object reference point at a known distance from a distal end of the second object; and (c) the distance of the first object along the path. Measuring the distance between the reference point of the first object and the reference point of the second object as means for calculating the relative position of the distal end and the distal end of the second object Is determined by

  If desired, the reference point of the first object and the reference point of the second object are initially aligned at the same position.

  Optionally, the second object is a catheter.

  If desired, the first object is a guide wire.

  If desired, the guidewire carries a tracking source at or near its distal end.

  If desired, the tracking source is a radiation source.

  According to one aspect of the present invention, a guidewire including a radiation source, the radiation source being formed integrally with or attached to the distal end of the guidewire Is provided.

  Optionally, the radiation ranges from 0.01 mCi to 0.5 mCi, optionally 0.1 mCi or less.

  If desired, the detectable amount is 0.05 mCi or less.

  If desired, the isotope is iridium-192.

In the simplified descriptive drawings of the drawings, the same structure, element, or part appearing in more than one figure is generally labeled with the same reference in all the figures in which they appear. Features and component dimensions shown in the figures are chosen for simplicity and clarity of explanation and are not necessarily to scale. The figures are listed below.

  FIG. 1 is a schematic diagram of the operational components of a system according to an exemplary embodiment of the present invention.

  FIG. 2 is a diagram illustrating the measurement of relative linear displacement according to an exemplary embodiment of the present invention.

  FIG. 3 illustrates an exemplary optical mechanism for measuring relative linear displacement according to an exemplary embodiment of the present invention.

  FIG. 4 illustrates machine readable markings on a guidewire according to an exemplary embodiment of the present invention.

  FIG. 5 illustrates an exemplary mechanical mechanism for measuring relative linear displacement according to an exemplary embodiment of the present invention.

  FIG. 1 determines the position of a second object moving along a first object using the position of the first object and a relative linear displacement according to an exemplary embodiment of the invention. A system 20 is shown. If desired, the series of positions defines a path for the first object. In the illustrated exemplary embodiment of the present invention, the second object is a catheter 70 and the first object is a guidewire 30. According to various embodiments of the present invention, the position may be a 3D position or a 2D position.

Measurement of the position of the first object:
In an exemplary embodiment of the invention, the guide wire 30 acting as the first object carries a tracking source. The tracking source can be any object against which the position sensing system can determine the position. According to various embodiments of the present invention, the tracking source can provide a signal or monitor the signal. If desired, the tracking source is located anywhere on the guidewire 30. In the exemplary embodiment of the invention, the tracking source is located at or near the distal end 32 of the guidewire 30. In an exemplary embodiment of the invention, the tracking source includes one or more radiation sources, RF transmitters and / or receivers, and / or magnets.

  The determination of the position of the RF signal source relative to one or more receivers is generally known in the art, and those skilled in the art will be able to incorporate any known method within the context of the present invention. There are methods based on recognition of signal strength at the signal source. These methods can be used to determine the position of the RF signal source and / or RF receiver positioned on the guidewire 30. A similar method can be used to track the magnet.

  Examples of radiation sources and detection systems for tracking them are described in co-pending application PCT / IL2005 / 000871, the disclosure of which is hereby fully incorporated by reference. The tracking system described relies on the sensor to determine the angle between the known sensor position and the tracking source. Each sensor uses one or more walls to cause a different distribution of radiation from the radiation source over the sensing area. Its distribution depends on the angle.

  One example of a sensor suitable for use in the context of the present invention is two sensors separated by an upright wall so that both sensors receive the same amount of incident radiation when the wall is directed at a radiation source. Use the sensor. When the detector and wall are rotated, the wall selectively blocks one of the sensors, causing an uneven distribution of incident radiation. This configuration relies on an equal distribution of radiation between the two sensors and maximum detection of incident radiation to indicate the correct angular orientation relative to the radiation source. Further configurations comprising two or more walls are also disclosed in application PCT / IL2005 / 000871.

  Calculation of intersections in two, optionally three, and optionally four or more directions provides a location for the tracking source. In an exemplary embodiment of the invention, tracking unit 34 ascertains and records the location of the tracking source at or near the distal end 32 of guidewire 30 periodically, as desired, and continuously. Alternatively or additionally, the position of the distal end 32 may be confirmed using an imaging device.

  The confirmed position of the distal end 32 of the guidewire 30 is displayed as a path in 3D position coordinates if desired. The sampling density of the tracking unit 34 is related to the accuracy of the determined path. The sampling density of the tracking unit 34 can be displayed as measured per unit time and / or measured per unit distance the tracking source travels, as desired. In an exemplary embodiment of the invention, the tracking unit 34 determines the position of the end 32 of the guidewire 30 once / second, optionally 10 times / second, optionally 20 times / second, optionally more than 50 times / second. calculate. Typically, as the sampling density increases, the need for interpolation decreases. In an exemplary embodiment of the invention, the ascertained position can be incorporated into a position output signal 36, eg, a signal 36 that includes a time stamp. The time stamp indicates when the position has been detected. The time may be a relative time measured from an arbitrary time point 0 or a clock time. If desired, the output signal 36 can be displayed, for example, as time + 2D position (t, X, Y) or time + 3D position (t, X, Y, Z). The time stamp allows correlation with other independently acquired data, as detailed below.

  The output signal 36 is communicated to the computer 60 as desired. In an exemplary embodiment of the invention, output signal 36 can be converted by computer 60 into a 3D position plot as a function of time. The term computer as used herein and in the appended claims includes computer circuitry, and includes, but is not limited to, ASICs.

  The use of a radiation tracking source has been used as an example, but other positioning such as using one or more of radioactive decay, radio frequency energy, ultrasonic energy, electromagnetic energy, NMR, CT, fluorescence indirect imaging System dependent embodiments may be used and are within the scope of the present invention. If desired, static and / or quasi-static electromagnetic fields are used for tracking.

Measurement of linear displacement of the first object:
Referring to FIG. 2, in an exemplary embodiment of the invention, linear displacement sensor 50 determines a linear displacement 100 at end 32 of guidewire 30 and displays it as a linear displacement value. The displacement sensor 50 may operate according to various mechanisms according to alternative exemplary embodiments of the invention as detailed below. In an exemplary embodiment of the invention, the measured displacement of the first object is aligned to its measured position so that the position can be displayed as a function of linear displacement.

  In an exemplary embodiment of the invention, sensor 50 does not act as a drive mechanism for guidewire 30; rather, sensor 50 aligns the path of guidewire 30 as guidewire 30 passes. In the exemplary embodiment of the invention, sensor 50 is incorporated into a drive mechanism for guidewire 30. If desired, the sensor 50 is fixed in a known position, for example by being located near the mouth that acts as an entry point into the femoral artery used in catheterization procedures. Fixing in a known position can be accomplished, for example, by securing the sensor 50 housing to the patient's leg or by attaching the sensor 50 housing to the operating table. In the exemplary embodiment of the invention, the position of sensor 50 is arbitrarily defined as zero displacement with respect to guidewire 30.

  In some embodiments of the present invention, the displacement sensor 50 includes a first sensing mechanism (eg, optical sensing) for measuring the linear displacement of the guide wire 30 and a second for measuring the linear displacement of the catheter 70. Depending on the sensing mechanism (eg mechanical sensing).

  In the exemplary embodiment of the invention, displacement sensor 50 relies on a similar mechanism to measure the displacement of both catheter 70 and guidewire 30. In an exemplary embodiment of the invention, the displacement of the catheter 70 is measured relative to the guidewire 30 using a machine readable code on the guidewire 30 as desired. If desired, the analysis circuit 60, which may be a computer, for example, calculates the distance 105 between the catheter end 72 and the guidewire end 32 located at the sensor 50. Alternatively or additionally, sensor 50 can be secured to guidewire 30 and / or catheter 70.

  In the exemplary embodiment of the invention, calibration is accomplished by reading the position on a common scale, such as reference numeral 38 of guidewire 30. According to this embodiment, guidewire 30 and catheter 70, each having a known length, are initially aligned so that an initial distance 105 between guidewire end 32 and catheter end 72 is recognized. Yes. For example, a guidewire 30 with a machine readable code that is marked in mm on a 1000 mm portion of the guidewire can be used. Sensor 50 is attached to the proximal end of catheter 70 and is held in a fixed position arbitrarily defined as zero displacement. The guide wire 30 is moved 100 mm into the body and the sensor 50 reads this displacement using a machine readable code on the guide wire 30. The distance 105 is increased by 100 mm at this stage. As the catheter 70 begins to be displaced, the sensor 50 is displaced along the guidewire 30. When this happens, the sensor 50 counts the number back using a machine readable code. For example, if the catheter 70 is advanced 25 mm, the sensor 50 will record 75 positions mm according to the sign. The distance 105 is reduced by 25 mm so that it is 75 mm greater than its initial value. Alternatively or additionally, sensor 50 records its movement for zero displacement.

  In an exemplary embodiment of the invention, an operator of system 20 can rapidly advance catheter 70 along guidewire 30. If desired, an output 62 indicating the distance 105 between the catheter end 72 and the guidewire end 32 alerts the operator when it must decelerate so that it can slowly approach the target. The output 62 can be displayed visually as a distance or by an audio device (eg, artificial speech). Alternatively or additionally, the warning indicator can warn the operator if the distance 105 is shorter than a predetermined limit. The warning indicator may be visible (eg, an icon or indicator light on the display screen) and / or audible (eg, a bell, buzzer, or artificial sound).

  In an exemplary embodiment of the invention, more than one target, such as an arterial plaque, is designated along a single path as guidewire 30 is advanced. In an exemplary embodiment of the invention, target designation is based on alignment with image data. If desired, the image data is acquired simultaneously with advancement of the guidewire 30. Alternatively or additionally, pre-acquired image data can be used to specify a target. The image data may be, for example, fluoroscopic image data. Alternatively or additionally, the target can be sensed by an increase in resistance to advancement of the end 32 of the guidewire 30. If desired, the system operator can instruct the computer 60 to designate a target. In an exemplary embodiment of the invention, the target is visible on the computer 60 display screen.

  The ends 72 of the catheter 70 can then be brought close to these targets based on their relative displacement on the path defined by the guidewire 30. Alternatively or additionally, the beginning and end of a single plaque may be defined as separate targets to facilitate plaque length measurement.

  In an exemplary embodiment of the invention, targets are mapped using a displacement sensor 50 such that each target is displayed as one or more linear displacement values. Alternatively or additionally, the targets are mapped using tracking unit 34 such that each target is displayed as one or more locations.

  The displacement 100 can be provided to the computer 60 as a displacement output signal 52 and can be time stamped as detailed above if desired. If desired, the computer 60 can calculate the linear displacement of the end 32 of the guidewire 30 as a function of time. Matching on image data such as fluoroscopy data and / or intravascular ultrasound data (IVUS) and / or arterial x-ray tomography data can be performed, for example, as detailed below. .

  Regardless of whether the target designation is actively performed by the operator of the system or performed passively by alignment with image data containing a visible target, a second such as a catheter Once the object is placed, it is useful to the system operator. Target designation can, for example, help an operator select a speed for catheter advancement.

  In certain embodiments of the invention, tracking of multiple elements on a single path is facilitated. This tracking can be simultaneous or sequential as desired. The plurality of elements can be, for example, a plurality of radiopaque markers and / or a plurality of radiation sources as detailed below.

  In an exemplary embodiment of the invention, multiple tracking sources can be tracked by multiple sensors. For example, the radiation source can be tracked by a directional sensitive radiation sensor as detailed above, and the RF source can be tracked by an RF sensing system. This may be useful, for example, in determining the direction of two points on a single object and / or adjusting the motion of two separate objects. Alternatively or additionally, multiple radiation sensors having different types of radiation can be tracked simultaneously using sensors specific to each radiation type. In an exemplary embodiment of the invention, only a single radiation source is used.

  If desired, linear displacement data can be calculated from a series of positions of the first object, such as the end 32 of the guidewire 30. The accuracy of this calculated displacement can be increased by increasing the number of determined positions per unit of displacement of the guidewire.

  Alternatively or additionally, the displacement of guidewire 30 and / or catheter 70 is not directly measured. In the exemplary embodiment of the invention, the displacement of the catheter 70 is measured relative to the guidewire 30.

Alignment of first object position and linear displacement:
In the exemplary embodiment of the invention, the position of end 32 of guidewire 30 is displayed as a function of displacement. If desired, the computer 60 correlates the position output signal 36 and the displacement output signal 52. If desired, the display of position as a function of displacement is useful in determining the position of a second object that moves along the same path where only displacement data is available.

  If desired, the output signals 36 and 52 are aligned one with respect to the other so that a single displacement measurement indicates a single position. This facilitates the display of the 3D position of the end 32 of the guidewire 30 as a function of linear displacement.

  If desired, output signals 52 and 36 (linear displacement and position, respectively) are matched one to the other via further parameters, eg, correlation with time. In some cases, the time stamps of output signals 52 and 36 do not match exactly, and an interpolation algorithm is performed to obtain a match. Interpolation may introduce inaccuracies in the alignment.

  In the exemplary embodiment of the invention, displacement output 52 has a sampling density greater than position output 36. In this case, the displacement more closely corresponding to the determined position is more accurate. It is possible to determine an estimate of error for a position corresponding to an arbitrary linear displacement position. If desired, this error estimate is displayed on the computer 60 display.

  In an exemplary embodiment of the invention, the 3D position of the end 32 of the guidewire 30 as a function of linear displacement is overlaid on a body part image or map, eg, a brain image or map, and / or Or matched. Alignment of the 3D position of the end 32 of the guidewire 30 as a function of linear displacement with the image or map can be achieved using methods known in the art. In an exemplary embodiment of the invention, the process generates an image, for example a brain image, with lines representing the path of the end 32 of the guidewire 30 superimposed on the image. If desired, linear displacement data is displayed along the line, for example by use of hash marks and / or indicating digits. This allows the operator to easily see from the display screen the distance at which the anatomical features of interest exist. Since the brain is static, image data acquired before and / or simultaneously with the treatment may be used.

  The alignment of the 3D position of the end 32 of the guidewire 30 as a function of linear displacement on a dynamic organ such as the heart is more complex. Additional alignment may be used to facilitate accurate alignment of the 3D position of the end 32 of the guidewire 30 with the image data of a dynamic body part (eg, a beating heart). In an exemplary embodiment of the invention, time-stamped image output (eg, fluorescence indirect imaging or IVUS) is provided to computer 60 simultaneously. If desired, the 3D position of the end 32 of the guidewire 30, the linear displacement of the end 32 of the guidewire 30, and the image data are all correlated with each other by a time stamp. The result of this multiple correlation is a plot of the 3D position of guidewire end 32 as a function of linear displacement superimposed on a static map of the body part. The static map represents a collection of relevant anatomical features from the dynamic image data drawn on the guidewire 30. This static map represents a path through the body that a second object, such as a catheter, can follow. The guide wire 30 acts as a runway along the route.

  Alternatively or additionally, once the end 32 of the guidewire 30 reaches the desired target, a straight line representation of the 3D position as a function of time (even regardless of the static map) is the second object. Indicates the path that will follow.

Measurement of the linear displacement of the second object:
In an exemplary embodiment of the invention, the linear displacement of a second object, such as catheter 70, is measured. Although a linear displacement of a single second object along the first object is described, according to an embodiment of the present invention, two or more second objects are first objects. Can be moved along. As shown in FIGS. 1 and 2, the catheter 70 with the distal end 72 can be moved along the guidewire 30 such that the catheter end 72 approaches the guidewire end 32. The linear displacement of the catheter 70 can be measured, for example, by a linear displacement sensor 50 as detailed below. The sensor 50 can engage and / or advance the catheter 70 by a mechanical mechanism such as a groove or arcuate tooth mesh. As desired, the catheter 70 and guidewire 30 can be measured by a single displacement sensor 50 or by different displacement sensors 50. For example, the displacement of the guide wire 30 may be sensed by the optical sensor 50, and the displacement of the catheter 70 along the guide wire 30 may be sensed by a mechanical sensor, or vice versa.

  In the exemplary embodiment of the invention, the catheter 70 carries a sensor 50 that reads the symbol 38 on the guidewire 30. For example, catheter 70 having a known length of 1000 mm can be positioned such that its proximal end is aligned with the proximal end of guidewire 30 having a known length of 2000 mm. Using this example, the end 32 of the guidewire 30 is advanced 767.3 mm into the body. This means that the catheter end 72 is 232.7 mm from the entrance of the femoral artery. A position sensor 50 at the proximal end of the catheter 70 reads 38 and / or mechanically measures the distance as the catheter 70 is advanced along the guidewire 30. This allows the distance 105 to be calculated by subtraction.

Confirmation of the position of the second object:
According to an exemplary embodiment of the present invention, once the linear displacement of the catheter end 72 is known, its position (optionally a 3D position) is determined as a function of the first object (eg, guide) as described above. It can be confirmed from a plot of the position of the end 32) of the wire 30. This is possible because the guidewire 30 and catheter 70 displacements are along a common path. In some cases, for example in cardiac catheterization, the entire path can be moved (eg, during cardiac contraction). However, this does not affect the relative linear displacement of the first object and the second object.

  Alternatively or additionally, the distance 105 between the catheter end 72 and the guidewire end 32 can be ascertained. If desired, this distance can be used to calculate the position coordinates of the catheter end 72 using, for example, a position plot as a function of the linear displacement of the guidewire 30 described above.

  In an exemplary embodiment of the invention, the displacement of the catheter end 72 is measured relative to any starting point outside the body. This starting point corresponds to a known position on the guidewire 30 measured relative to the guidewire end 32. If the length of the catheter 70 is known, the distance 105 can be calculated. For example, if the known starting point is 950 mm from the guidewire end 32 and the proximal end of the catheter 70 is advanced 150 mm along the guidewire 30, the proximal end of the catheter is 800 mm from the guidewire end 32 right. If the catheter has a length of 600 mm, the catheter end 72 will have a distance 105 of 200 mm from the guidewire end 32.

  In the exemplary embodiment of the invention, the displacement of the catheter end 72 is measured relative to the guidewire end 32. For example, if a catheter 30 carrying a machine readable code is used, the sensor 50 attached to the end 72 of the catheter 70 can directly read the distance 105 from the end 32 of the catheter 30.

  In an exemplary embodiment of the invention, guidewire 30 can undergo an additional linear displacement 120 after catheter 70 is inserted into the body. Typically, this additional linear displacement will change the incremental distance 105 but does not cause a change in the calculated position of the end 72 of the catheter 70. For example, if the guide wire 30 is inserted 100 cm when measured by the sensor 50 and the catheter 70 is inserted 85 cm along the guide wire, a relative displacement 105 of 15 cm is calculated. The 3D position of the end 72 of the catheter 70 can be determined from a plot of the position as a function of the linear displacement of the guidewire 30 described above. If the guidewire 30 is further advanced 10 cm, the relative displacement 105 between the end 32 of the guidewire 30 and the end 72 of the catheter 70 increases to 25 cm, but the position of the end 72 of the catheter 70 changes as desired. Can remain untouched.

  If the guidewire 30 and the catheter 70 are each further advanced 10 cm, the relative displacement 105 between the end 32 of the guidewire 30 and the end 72 of the catheter 70 remains unchanged, but the end 72 of the catheter 70 remains unchanged. The position can be advanced along the path determined by the guidewire end 32 if desired.

  In an exemplary embodiment of the invention, guidewire 30 is advanced first and catheter 70 follows along the guidewire. This results in a temporary increase in distance 105 that is later offset by advancement of catheter end 72.

  Alternatively or additionally, the catheter end 72 can be advanced while causing a decrease in the distance 105, and the decrease in the distance 105 is substantially offset by further advancement of the guidewire end 32.

  In an exemplary embodiment of the invention, guidewire 30 and / or catheter 70 can be partially retracted and then advanced along different paths. This may be useful, for example, in a combined PTCA / angiography procedure or in a procedure in which PCTA of multiple coronary arteries is performed.

  Regardless of the magnitude and / or order of change in displacement of the catheter end 72 and the guidewire end 32, the relative displacement 105 and the 3D position of the end 72 is the position of the guidewire end 32 or any other tracking portion of the guidewire And from the displacement data.

  In an exemplary embodiment of the invention, the accuracy of the 3D position determined by the tracking monitor 34 relative to the guidewire end 32 is high (eg, 2 mm, optionally 1 mm, optionally 0.5 mm, optionally 0.1 mm). Less than). In exemplary embodiments of the invention, measuring the displacement of the catheter end 72 and / or guidewire end 32 does not significantly reduce this accuracy. As described in detail below, an optical displacement sensing mechanism having an accuracy in the range of tens of nanometers has been described, and a mechanical sensing mechanism having a sensitivity of 0.5-0.6 mm is well known in the art. It is. If desired, the linear displacements of the first and second objects (eg, guidewire 30 and catheter 70) are each within 2 mm, optionally 1 mm, optionally 0.5 mm, optionally within 0.1 mm or less. Is as accurate as In an exemplary embodiment of the invention, the sum of errors in distance 105 between catheter end 72 and guidewire end 32 is 2 mm, optionally 1.5 mm, optionally 1.0 mm, optionally 0.5 mm or less. Is not exceeded.

  In some embodiments of the present invention, the position of the end 32 of the guidewire 30 is defined as a 2D position (ie, X, Y). Alternatively or additionally, the position of the end 32 of the guidewire 30 is defined as a 3D position (ie, X, Y, Z). As desired, the position plot of the first object is a 2D position plot or a 3D position plot.

  In certain exemplary embodiments of the present invention, the position can be defined in vector as a combination of angle and distance. For example, the position of the end 32 of the guidewire 30 can be defined as a rotation angle, an elevation angle, and a distance to a defined point. If desired, the defined point can be an anatomical marker. For example, in an intracranial procedure, the incision point in the skull can be used as a reference point, and the position relative to this marker can be determined using a near field RF transceiver.

  The use of 2D position may be useful, for example, in intra-limb catheterization. The use of 3D positions is useful, for example, in cerebral catheter procedures including but not limited to AVM procedures and / or intra-arterial stroke procedures, and cardiac catheter procedures including but not limited to angiography and / or angioplasty. there will be.

  If desired, the output is displayed to the user so that the relative position of the catheter end 72 and the guidewire end 32 can be seen and understood, for example, on a display screen.

  In an exemplary embodiment of the invention, a standard catheter 70 without a tracking source 70 is used while an accurate determination of its end 72 position is achieved. A sensor 50 that measures the displacement of the catheter 70 allows a tracking source to be placed on the guidewire 30.

  In an exemplary embodiment of the invention, a standard guidewire 30 without a machine readable code is used and a mechanical displacement sensor 50 is used to measure the linear displacement of the guidewire.

Exemplary Linear Displacement Sensor Type-Optical Sensor:
Referring to FIG. 3, in an exemplary embodiment of the invention, linear displacement sensor 50 is used to read a machine-readable code 38 optically encoded on guidewire 30 and / or catheter 70, for example 1 Optical sensing means 54 such as one or more CCD elements 55 (e.g., CCD elements are available from Hamamatsu Photonics, Japan) are used. These markings can indicate, for example, how much the object (eg, guidewire 30 and / or catheter 70) has passed a predetermined point. Mechanisms for optical sensing are well known to those skilled in the art and can be incorporated into the context of the present invention. The code 38 may be a relative code that depends on counting or may be an absolute code that allows the displacement to be determined from a single reading. In an exemplary embodiment of the invention, a combination of absolute and relative codes is used.

  Referring to FIG. 4, in an exemplary embodiment of the invention, reference numeral 38 includes a segment indicator 40 of a known length, which is optionally organized organically in groups of sub-segments. If desired, the sensor 50 has a reading frame that is longer than the sub-segment so that each sub-segment is read accurately. Optionally, reference numeral 38 includes a start marking 40 that indicates the initial distance from the end 32 of the guidewire 30. For example, the starting code can be located 1000 mm from the end 32 and the code 38 can extend 500 mm along the guidewire 30 from the end 32 toward the proximal end. This allows the initial increment of guidewire insertion to be accurately aligned without incremental measurement. In some uses, the initial approach of the guidewire to the area of interest is not subject to position analysis. For example, the exact position of the end 32 of the guidewire 30 as it moves through the femoral artery toward the heart is of relatively less interest, but the end 32 of the guidewire 30 once it has entered the pulmonary system. The exact position of is of great interest. If desired, sub-segments (not shown) are also shown. In the exemplary embodiment of the invention, symbol 38 is a bar code. In the exemplary embodiment of the invention, code 38 uses a unique pattern, such as a start code, for each segment 40.

  In certain exemplary embodiments of the invention, segments and / or subsegments are counted continuously. In an exemplary embodiment of the invention, each of the segments 40 further includes a binary encoding of segment numbers. For example, segment number 13 can be encoded as 1101 in binary, which is rewritten as a black / white code of black, black, white, black (assuming black is 1). A code that uses a 0.1 mm bandwidth read by 100 CCD elements 55 that are each 0.1 mm wide can yield a measurement accuracy of 0.1 or better. If desired, light is supplied from an internal source, such as an LED light source, which is a sensor 50 that illuminates 38. If desired, the LSB (least significant bit) of the segment code starts at a known distance from the start code so that each digit line is aligned in the correct position. In an exemplary embodiment of the invention, the line width of the start marking is different from the code pattern so that the sensor 50 does not confuse the start marking with a binary code (eg, each line may be 1.5 times wider). ). In the exemplary embodiment of the present invention, the line width matches the width of the CCD element 55, except for a starting marking that is wider than the CCD element 55. If desired, the starting marking is defined as a mark that aligns simultaneously on the two CCD elements 55. If desired, error checking techniques (eg, a parity mechanism) can be used to reduce errors when interpreting the code. In an exemplary embodiment of the invention, the symbol 38 can be read using a vernier scale to increase accuracy. If desired, positioning of the CCD element 55 can create a vernier scale.

  Alternatively or additionally, code 38 may use Moire modulation of the overlapping grating to generate fringes. This technique can theoretically produce resolutions in the 14 nm range for 10 micron spaced gratings (Suezou Nakadate et al. (2004) Meas. Sci. Technol. 1: 1462-1455). This article is fully incorporated herein by reference. In an exemplary embodiment of the invention, a set of grids can be placed on or attached to a portion of guidewire 30. Alternatively or additionally, a set of grids can be placed on or attached to a portion of the catheter 70. Alternatively or additionally, a set of grids can be inserted between the CCD element 55 and the guidewire 30 and / or a portion of the catheter 70.

  In an exemplary embodiment of the invention, to estimate the absolute position of the sensor 50 along the guidewire 30, a position measurement algorithm installed on the computer 60 (optionally an ASIC device) identifies the starting pattern and optionally the sensor. Measure its position in the image. The segment number is derived from the binary encoding as desired. The position can then be calculated by multiplying the segment number by the segment length and adding the starting pattern position in the image. If desired, an array of multiple CCD elements 55 is used so that the position of the boundary between two consecutive segments within the distance covered by the array can be ascertained as it moves past the array. The In an exemplary embodiment of the invention, sensor 50 operates on a linear portion of guidewire 30 and / or catheter 70 that is located outside the patient's body. This reduces measurement errors that can be caused by bending.

  For example, if the length of the segment is 10 mm, the algorithm may detect that the starting pattern is 7.3 mm from the start of the image (acting as a reference point), and the binary code is the segment number The absolute position of the sensor 50 along the guide wire is (46) × 10 + 7.3 = 467.3 mm. If desired, the start signal is positioned at a known distance from the end 32 of the guidewire 30 as detailed above. In that case, the known distance must be added to the calculated displacement. Using the above example, a guide wire 30 with a start signal of 300 mm from the end 32 will be used because the first 300 mm movement after insertion into the femoral artery is typically of no medical interest. Let's go. In this case, adding 300 mm to the calculated displacement would give a total displacement of 767.3 mm.

Exemplary Linear Displacement Sensor Type-Mechanical Sensor:
Referring to FIG. 5, in an exemplary embodiment of the invention, the linear displacement sensor 50 uses, for example, one or more calibrated wheels 56 or mechanical sensing means 54 such as gears. Measure how much the catheter 70 and / or the guide wire 30 has passed a predetermined point. According to this embodiment of the invention, the sensing is a sensing of the total number of forward rotations of the wheels 56, not the measured object (eg, guidewire 30 and / or catheter 70) itself.

  In an exemplary embodiment of the invention, wheel 56 has a diameter of 1 cm and sensor 50 is sensitive to a 3 degree rotation of wheel 56 to provide a measurement increment of about 0.56 mm. Smaller wheels and / or higher rotational sensitivity can allow measurement of smaller incremental displacements.

  In an exemplary embodiment of the invention, the degree of slip between wheel 56 and the measured object is sufficiently small that it does not introduce a significant error in the measurement. If desired, the catheter 70 and / or guidewire 30 is toothed or scored that engages a mating tooth / scored on the wheel 56 to increase friction and / or prevent slippage. Alternatively or additionally, the one or more wheels 56 are not part of a drive mechanism that propels the catheter 70 and / or guidewire 30 forward, and optionally by the notches or teeth described above, the catheter 70 and / or Or the guide wire 30 is passively rotated by the catheter 70 or guide wire 30 as it passes across the wheel. Regardless of whether the wheel 56 drives the catheter 70 and / or the guide wire 30 or the wheel 56 is driven by these objects, the number of revolutions that the wheel 56 rotates is known to the wheel circumference. As long as it can be detected and converted into a linear displacement of the catheter 70 and / or guidewire 30.

  Mechanisms for detecting and recording the number of wheel revolutions are well known to those skilled in the art and can be incorporated into the context of the present invention (e.g., the mechanism is WM Berg Inc., NY, NY). , Available from USA).

  In the exemplary embodiment of the invention, wheel 56 is operated by a stepper motor that moves guidewire 30 and / or catheter 70 in defined increments.

Assembly In an exemplary embodiment of the invention, a catheter 70 having a portion of known length 110 is attached to a portion of guidewire 30 of known length 100 and moves along the guidewire.

  In an exemplary embodiment of the invention, the first sensor 50 is fixed in a defined position detailed above and measures the displacement of the guide wire 30 relative to this defined position detailed above. In the exemplary embodiment of the invention, second sensor 50 is attached to the proximal portion of catheter 70. If desired, the attachment is made at a known distance from the defined position of the first sensor. Alternatively or additionally, an initial distance between the second sensor and the first sensor can be determined. The initial distance can be determined, for example, by having each of the two sensors read a different portion of symbol 38 on the guidewire 30. Alternatively or additionally, the initial distance between the two sensors 50 may be measured manually.

  In an exemplary embodiment of the invention, the assembly of guidewire 30 and catheter 70 is such that their initial distance 105 can be calculated using known catheter and guidewire lengths. Including alignment of the distal end. Alternatively or additionally, a mark on the guidewire 30 at a known distance from the guidewire end 32 may indicate a desired attachment point for the second sensor 50 of the catheter 70.

  The assembly of the components can be done at the manufacturing facility and / or at the point of use. In an exemplary embodiment of the invention, guidewire 30, catheter 70, and sensor 50 are provided as a pre-calibrated unit that is assembled.

  In an exemplary embodiment of the invention, radiopaque markers on guidewire 30 and / or catheter 70 are used for alignment and / or calibration. If desired, the radiation source is also radiopaque. In an exemplary embodiment of the invention, the radiopaque marker is placed on the guidewire 30 at a known distance (eg, every 50 mm) from the end 32 of the guidewire 30. Once the position of end 32 is determined as a function of displacement, the positions of all these markers can be identified and displayed. If desired, this display of radiopaque markers along the path the catheter end 32 travels allows the distance between the end 72 of the catheter 70 and each radiopaque marker to be determined.

  In an exemplary embodiment of the invention, a stent and / or PCTA balloon placed at or near the end 72 of the catheter 70 acts as a radiopaque marker and / or a radiation marker.

Incorporating a radiation tracking source into the guidewire:
The radiation tracking source can be incorporated into a variety of existing instruments such as guidewire 30. If desired, this facilitates instrument tracking by tracking the tracking source. However, the use of multiple radiation sources on the same guidewire or multiple instruments may cause mutual interference with tracking. In an exemplary embodiment of the invention, a single radiation source is used.

  Integration may be at any desired location on the guidewire 30, for example at or near the guidewire end 32. The ionizing radiation source can be formed integrally with a portion of the guidewire 30 or attached to a portion of the guidewire 30. Attachment can be done, for example, by gluing or welding the radiation source onto the guidewire 30. Alternatively or additionally, attachment is accomplished by supplying the radiation source as an adhesive tag (eg, crack and peel sticker), radioactive paint or radioactive adhesive that can be applied to the guidewire. If desired, the ionizing radiation source is provided as a specific length of wire containing a solid, eg, a radioisotope. A short single wire containing the desired isotope can be attached to the guide wire by inserting it into a groove on the guide wire and gluing it in place. This results in simultaneous position measurement of the guide wire and the radiation source. The radiation source can be formed integrally with the guide wire, for example by extruding the solid radiation source simultaneously with the guide wire during manufacture of the guide wire. Alternatively or additionally, the ionizing radiation source can be supplied as a radioactive fluid that can be applied to the porous end 32 of the guidewire 30 and dried and / or solidified and / or absorbed. Regardless of the exact form in which the ionizing radiation source is supplied to or attached to the guidewire, it should leave any significant radioactive residue in the subject's body after it is removed from the body at the end of the medical procedure is not. In an exemplary embodiment of the invention, the amount of radioactive material used for tracking can be low, and significant radioactive residue issues are less important. In exemplary embodiments of the present invention, a large amount of radioactive material is used, and significant radioactive residue issues are more important. In an exemplary embodiment of the invention, a standard guidewire 30 is incorporated into the context of the present invention by attaching a radiation source near the end 32.

  In general, guidewires for cardiovascular applications are long, thin, flexible springs used to guide and position intravascular catheters (Online Medical Dictionary; University of Newcastle up Tyne <// cacerweb.ncl.ac.uk>). If desired, the guide wire is rigid enough that it is routed into the body through an opening, eg, a mouth to an artery, and it travels a path through the body (eg, through a blood vessel) Sufficient flexibility. A rigid guidewire can be used for orthopedic applications.

  In an exemplary embodiment of the invention, a guide sheath can be used in addition to or instead of a guidewire. The guide sheath can be used in the context of pulmonary and / or intracranial and / or orthopedic applications. In an exemplary embodiment of the invention, the guide sheath is bent and one or more tracking sources are placed on the curve. The guide wire or guide sheath can then act as a runway for a second object, such as a catheter described in greater detail above.

  Catheter 70 optionally carries a PTCA balloon or stent near end 72 and / or includes one or more dye inlets near end 72. The catheter 70 delivering the stent can use a radiopaque stent, which is useful in calibration if desired, for example, in the calibration of the linear displacement of the end 72 of the catheter 70. Alternatively or additionally, the guidewire 30 can have one or more radiopaque portions for calibration of the linear displacement of the end 32 of the guidewire 30. If desired, these radiopaque portions are metal and are placed along the guidewire 30 at known intervals.

  For those embodiments of the invention that use a radiation tracking source, 0.01 mCi to 0.5 mCi, optionally 0.1 mCi or less, optionally 0.05 mCi or less, can allow accurate tracking. . One isotope suitable for use in this context is iridium-192. This type of radiation source can be tracked, for example, by a system that includes an angular direction dependent three-way sensor module that works in concert to determine the position of the radiation source detailed above.

  Although the present invention has been described in the context of catheters and guidewires, optionally cardiac catheters and guidewires, the scope of the present invention is broad and includes those performed in the heart, lungs, kidneys, brain, bones and gallbladder, Includes, but is not limited to, paired instrument combinations adapted for a wide variety of medical procedures. Alternatively or additionally, the operating principles described above can be used in other contexts, including but not limited to endoscopy and / or guided biopsy procedures. In an exemplary embodiment of the invention, an endoscope carrying a tracking source and a camera is used to define one or more targets, replacing the linear displacements described above. A medical instrument, such as a biopsy sampler, is then propelled along the endoscope and stopped at the linear displacement previously determined to be the target.

  In the description and claims of this application, the verbs “comprise”, “include”, “have” and their conjugations each include their conjugations. , Used to indicate that the verb object is not necessarily a complete list of members, components, elements, or parts of the subject of the verb.

  Some exemplary systems and methods according to the present invention rely on the execution of various commands and the analysis and conversion of various data inputs. Any of these commands, analysis, or transformations can be accomplished by software, hardware, or firmware in accordance with various alternative embodiments of the present invention. In an exemplary embodiment of the invention, the machine-readable medium includes instructions for aligning linear displacement data of the second object on the position plot of the first object, and / or described herein. Implementation of the method. In the exemplary embodiment of the invention, computer 60 executes instructions for alignment and / or data acquisition.

  Although the present invention has been described using detailed descriptions of embodiments thereof, it has been presented by way of example only and is not necessarily intended to limit the scope of the invention. In particular, the numerical values may be higher or lower than the numerical ranges described above and still fall within the scope of the present invention. The described embodiments comprise various features, not all of which are required for all embodiments of the invention. Some embodiments of the invention utilize only some of the features or possible combinations of features. Alternatively or additionally, portions of the invention described / depicted as a single unit may comprise two or more separate physics that act in concert to perform the described / depicted functions. It can exist as a real entity. Alternatively or additionally, portions of the present invention described / depicted as two or more separate physical entities may be combined into a single physical entity for performing the described / depicted functions. Can be integrated. Embodiments of the invention that include variations of the described embodiments of the invention, and different combinations of features shown in the described embodiments, are described in the context of one embodiment in the context of other embodiments. Can be combined in all possible combinations including, but not limited to. The scope of the present invention is limited only by the appended claims.

  All publications and / or patents and / or patent applications cited herein are hereby incorporated by reference in their entirety as if each was specifically and individually incorporated by reference. Incorporated.

FIG. 3 is a schematic diagram of the operational components of a system according to an exemplary embodiment of the present invention. FIG. 6 illustrates relative linear displacement measurement according to an exemplary embodiment of the present invention. Fig. 4 illustrates an exemplary optical mechanism for measuring relative linear displacement according to an exemplary embodiment of the present invention. Fig. 4 shows machine readable markings on a guide wire according to an exemplary embodiment of the invention. Fig. 4 illustrates an exemplary mechanical mechanism for measuring relative linear displacement according to an exemplary embodiment of the present invention.

Claims (42)

A method of determining a position of a second object that moves along a first object, the method comprising:
(A) determining a position for the first object;
(B) determining a linear displacement of a second object relative to the first object; and (c) based on the position of the first object and the linear displacement with respect to the first object. And confirming the position of the second object.   The method of claim 1, further comprising measuring a linear displacement of the first object.   The method of claim 2, wherein the linear displacement of the first object and the linear displacement of the second object are each determined relative to a predetermined point.   4. The method of claim 3, wherein the defined point used for the first object and the second object is a single defined point.   The defined points used for the first object and the second object are two separate defined points, and the method is used to determine a linear displacement of the first object. Calculating a linear distance between the first defined point and a second defined point used to determine a linear displacement of the second object, and the second distance according to the second defined point. The method of claim 3, further comprising correcting a linear displacement value of the object.   The determination of the position and the linear displacement for the first object is repeated to determine a series of linear displacements at a correlation position, the series of correlation positions defining a path. the method of.   The method of claim 1, wherein determining a linear displacement value for the second object is relative to a defined point on the first object.   The method of claim 1, wherein the second object is a catheter.   The method of claim 1, wherein the first object is a guide wire.   The method of claim 9, wherein the guidewire carries a tracking source at or near its distal end.   The method of claim 10, wherein the tracking source is a radiation source.   A system for performing a medical procedure, the system including at least two axially extendable members that are at least partially insertable into the body, of the axially extendable members, At least one is marked with an array of machine readable markings configured to help determine relative linear displacement along a common path of the at least two axially extendable members with respect to each other.   The system of claim 12, wherein the machine readable marking indicates a length increment.   The system of claim 12, further comprising a tracking source located at a distal portion of one of the axially extendable members.   The system of claim 14, wherein the tracking source is a radiation source.   The system of claim 12, wherein the machine readable marking comprises a binary code.   The system of claim 12, wherein the axially extendable member comprises a catheter.   The system of claim 12, wherein the axially extendable member comprises a catheter guide wire.   The system of claim 18, wherein the catheter guidewire carries an array of the machine readable markings. A system for determining a position of a first object and a second object that move along a common path, the system comprising:
(A) a first object including a tracking source that is subject to displacement along the path;
(B) a second object subject to displacement along the first object; and (c) determining a relative displacement of the first object and the second object along the path. A system comprising a displacement sensor designed and configured in such a manner.   21. The system of claim 20, further comprising a circuit that converts the relative displacement of the first object and the second object along the path to a position of the second object.   21. The system of claim 20, wherein the tracking source includes radioactive decay.   The system of claim 20, wherein the displacement sensor includes an optical sensing mechanism.   24. The system of claim 23, wherein the optical sensing mechanism reads a binary code.   The system of claim 20, wherein the displacement sensor includes a mechanical sensing mechanism.   The system of claim 20, wherein the first object includes a guide wire.   21. The system of claim 20, wherein the second object includes a catheter. A method of determining a position of a second object that moves along a first object, the method comprising:
(A) determining a path along which at least one point on the first object moves;
(B) determining a linear displacement of at least one point on the second object while moving the second object along the path; and (c) on the first object. Determining a position of a selected portion of the second object by calculating a course along a path of at least one point.   30. The method of claim 28, wherein the calculation depends on the linear displacement. The course along the path of the first object is
(A) using a fixed known length for at least a portion of each of the first and second objects; and (b) the second object along the first object. 29. The method of claim 28, determined by measuring a relative displacement of the at least one point above.   32. The method of claim 30, wherein measuring the relative displacement is performed outside the subject's body. The linear displacement is
(A) defining a reference point of the first object at a known distance from a distal end of the first object;
(B) defining a second object reference point at a known distance from a distal end of the second object; and (c) the distance of the first object along the path. Measuring the distance between the reference point of the first object and the reference point of the second object as means for calculating the relative position of the distal end and the distal end of the second object 30. The method of claim 28, wherein:   33. The method of claim 32, wherein the first object reference point and the second object reference point are initially aligned at the same location.   30. The method of claim 28, wherein the second object is a catheter.   30. The method of claim 28, wherein the first object is a guide wire.   36. The method of claim 35, wherein the guidewire carries a tracking source at or near its distal end.   40. The method of claim 36, wherein the tracking source is a radiation source.   A guidewire comprising a radiation source, wherein the radiation source is integrally formed with or attached to the distal end of the guidewire.   39. The guidewire of claim 38, wherein the radiation is in the range of 0.01 mCi to 0.5 mCi.   39. The guidewire of claim 38, wherein the detectable amount is 0.1 mCi or less.   39. The guidewire of claim 38, wherein the detectable amount is 0.05 mCi or less.   39. The guidewire of claim 38, wherein the isotope is iridium-192.

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