Puncture guide for computer tomography

What is claimed is:

1. An apparatus for guiding a puncture instrument through an entry point in the body of a patient to a target location within said body of said patient, comprising:

support means for establishing a fixed reference point adjacent to said body of said patient;

path determining means mounted to said support means and adjustable to define a path through said entry point in a predetermined direction;

instrument holding means mounted to said path determining means and slidably movable with respect thereto along said path defined by said path determining means for holding a puncture instrument and for moving said puncture instrument along said path defined by said path determining means; and

depth determining means operatively associated with said path determining means for limiting the extent of said movement of said puncture instrument along said path, whereby said puncture instrument penetrates the patient's body to a predetermined depth.

2. The apparatus of claim 1, further comprising instrument guide means operatively associated with said path determining means for guiding said puncture instrument as said puncture instrument is moved along said path defined by said path determining means.

3. The apparatus of claim 2, wherein said instrument guide means automatically disengages from said puncture instrument when said depth determining means limits said extent of said movement of said puncture instrument.

4. The apparatus of claim 3, wherein said instrument guide means comprises a pair of cooperating jaws mounted to said path determining means and which disengage from said puncture instrument when said depth determining means limits said extent of said movement of said puncture instrument.

5. The apparatus of claim 4, wherein said pair of cooperating jaws are pivotably mounted to said path determining means for articulation in a horizontal plane, and wherein both of said jaws pivotably disengage from said puncture instrument when said depth determining means limits said extent of said movement of said puncture instrument.

6. The apparatus of claim 4, wherein one of said pair of cooperating jaws is pivotably mounted to said path determining means for articulation in a horizontal plane, and wherein said one of said pair of cooperating jaws pivotably disengages from said puncture instrument when said depth determining means limits said extent of said movement of said puncture instrument.

7. The apparatus of claim 2, wherein said instrument guide means is removably mounted to said path determining means.

8. The apparatus of claim 1, further comprising recoil suppression means operatively associated with said depth determining means for capturing said puncture instrument when said depth determining means limits said extent of said movement of said puncture instrument to prevent said puncture instrument from recoiling.

9. The apparatus of claim 1, wherein said patient lies on a support surface, and wherein said support means for establishing a fixed reference point adjacent to said body of said patient comprises:

a track mounted to said support surface;

a carriage movably mounted to said track; and

a support arm mounted to said carriage, said path determining means being mounted to said support arm.

10. The apparatus of claim 9, wherein said track comprises a curved upper surface for minimizing artifacts when said apparatus is used in conjunction with imaging technology.

11. The apparatus of claim 9, wherein said support arm is pivotably mounted to said carriage about a horizontal axis of rotation such that said support arm can be angularly adjusted with respect to said carriage.

12. The apparatus of claim 1, wherein said target location within said body of said patient is identified by means of imaging technology, wherein said predetermined direction and said predetermined depth are computed from an image obtained by said imaging technology, and wherein said path determining means further comprises an angle indication means for indicating the angle of said path determining means, whereby said path determining means can be aligned along said predetermined direction by reference to said angle indication means to direct said puncture instrument to a location identified on said image.

13. The apparatus of claim 1, further comprising at least one scale located on said path determining means and calibrated with respect to said puncture instrument for indicating a depth to which said puncture instrument will penetrate the body of said patient, whereby said depth determining means can be aligned with a desired location on said scale to determine said predetermined depth to which said puncture instrument will penetrate said body of said patient.

14. The apparatus of claim 13, further comprising means for removably mounting said scale to said path determining means to accommodate a variety of said scales calibrated to a variety of puncture instruments.

15. The apparatus of claim 14, wherein said means for removably mounting said scale to said path determining means comprises channel means formed on said path determining means for slidably receiving a scale therewithin.

16. The apparatus of claim 1, wherein said path defined by said path determining means comprises a slot means, and wherein said instrument holding means comprises a sleeve for holding said puncture instrument, said sleeve having flange means for slidably engaging said slot means for moving said puncture instrument along said path defined by said path determining means.

17. The apparatus of claim 16, wherein said depth determining means operatively associated with said path determining means for limiting the extent of said movement of said puncture instrument along said path comprises a shelf operatively associated with said slot means and movable along said slot means, said sleeve abutting said slot means to limit the extent of movement of said puncture instrument along said slot means.

18. The apparatus of claim 17, further comprising recoil suppression means operatively associated with said shelf and said sleeve for locking said sleeve to said shelf when said sleeve abuts said shelf, thereby to prevent said puncture instrument from recoiling.

19. A method for retrieving a tissue specimen from the body of a patient using a puncture guidance device comprising a path determining means mounted to a support means and angularly adjustable with respect thereto, and an instrument holding means mounted to said path determining means and slidably movable with respect thereto such that the needle of a biopsy instrument mounted to said path determining means will follow a path defined by said path determining means as said instrument holding means slides with respect to said path determining means, said instrument holding means having a length of travel with respect to said path determining means which is adjustable by a user, said method comprising the steps of:

placing a marking device comprising a plurality of parallel, spaced-apart X-ray opaque markers on the body of the patient such that the marking device lies generally in the plane within which an image is to be taken and such that the markers are disposed perpendicularly to the plane within which said image is to be taken;

taking an image of the patient in an image plane using suitable imaging technology;

identifying a target location within the body of the patient from said image;

identifying from said image an optimum line of penetration from outside the patient's body to said target location within the patient's body;

identifying on said image an entry location at which said line of penetration intersects the patient's skin;

identifying the X-ray opaque markers on said image adjacent said entry location;

identifying the image plane on the patient's body corresponding to the plane of said image;

identifying the X-ray opaque markers on the patient's body corresponding to the identified markers adjacent said entry location;

locating the entry location on the patient's body in the identified image plane and between the identified X-ray opaque markers;

measuring the angle and depth of penetration on said image along said optimum line of penetration to said target location within the patient's body;

aligning said path determining means of said puncture guidance device such that said path defined by said path determining means corresponds to said measured angle of said optimum line of penetration; and

adjusting said length of travel of said instrument holding means with respect to said path determining means such that a needle tip of a biopsy instrument mounted to said instrument holding means will penetrate to said measured depth of penetration to said target location;

whereby when said instrument holding means is slidably advanced with respect to said path determining means, the needle tip of a biopsy instrument mounted to said instrument holding means will travel along a path intersecting said target location to a depth corresponding to said target location to position said needle tip for retrieving a biopsy specimen from said target location.

20. The method of claim 19, wherein said guidance device includes a bore for guiding a needle along said line of needle travel and further comprises an angle meter for indicating the angle of said line of needle travel, and wherein said step of setting a puncture guidance device to guide a needle at said measured angle through said entry location on the patient's body comprises the steps of:

sighting through said bore in said guidance device to align said bore with said entry location; and

while maintaining said bore aligned with said entry location, adjusting said guidance device until said angle meter indicates said line of needle travel to be at an angle corresponding to the angle of said optimum line of penetration as measured on said image.

21. An apparatus for mounting a tissue sampling instrument to a guidance device, said guidance device having a slot means defining a path of travel, and said apparatus comprising:

sleeve means for receiving a tissue sampling instrument therein such that said instrument is retained within said sleeve means; and

flange means operatively associated with said sleeve means for slidably engaging said slot means in said guidance device, said apparatus thereby being slidably mounted to said guidance device to guide said tissue sampling instrument along said path of travel.

22. The apparatus of claim 21, wherein said sleeve means is configured such that said instrument is retained within said sleeve means by an interference fit between said sleeve means and said instrument.

Description Submit all comments and votes

TECHNICAL FIELD

The present invention relates generally to an apparatus and method for guiding a biopsy needle to a desired location within a patient's body and relates more specifically to a puncture guide for use in conjunction with computer tomography and method for use thereof.

BACKGROUND OF THE INVENTION

Today ultrasonics, X-ray, computer tomography (also known as "CT scan"), and other imaging technologies are used to visualize and localize pathological changes, e.g. tumors, within a patient's body. X-ray and ultrasonics have limited use in visualizing and localizing such tumors because the body constitution of the patient often hides the suspected pathological change and because small changes cannot be detected. Computer tomography does not have these limitations.

Once a suspected pathological change has been located with a visualization apparatus such as CT scan, it is necessary to retrieve a tissue sample of the suspected tumor for biopsy. Tissue samples are commonly obtained by puncturing the skin of the patient with a biopsy needle, guiding the needle to the site of the suspected tumor, and withdrawing a sample of the tissue. Punctures in the thorax, abdomen and pelvis are conventionally performed by hand after suitable localization of the pathological change. Vertically performed punctures are usually relatively simple to accomplish and provide a relatively high frequency of acceptable tissue specimens, while punctures performed by hand which require an angling of the puncture needle cannot be performed without difficulty and give a lower frequency of successful results. Furthermore, when retrieving tissue samples of small pathological changes, it is very difficult, if not impossible, to hit the target tissue or organ when guiding the needle by hand.

Thus, there is a need for an apparatus which permits accurate and easy retrieval of acceptable tissue specimens from locations within the body of a patient which require angling of the needle to reach the target tissue.

There is a further need for an apparatus which permits accurate and easy retrieval of tissue speciments from small pathological changes.

Various instruments are known for assisting in guiding biopsy needles to a location identified by computer tomography. One such puncture instrument comprises a needle guide which can be angled and is mounted on a stand arranged on the patient table. The stand is vertically and horizontally adjustable relative to the patient table, and the needle guide is either displaceably mounted on the stand or the stand is displaceably mounted to the patient table. Adjustments can be made in x-, y- and z-directions, and the needle guide can be angled 0.degree.-180.degree.. With this instrument, however, repeated attempts are often necessary to obtain an acceptable specimen from the target tissue. Such repeated efforts are time consuming, increase the expense of the procedure, and are painful for the patient in cases where local anesthetic cannot be administered. Furthermore, where multiple attempts are necessary to retrieve a satisfactory tissue sample, additional CT images are required to check needle placement, exposing the patient to further radiation and tying up the CT table for extended periods of time. Also, known prior art guidance devices cannot be brought with the patient into the tomograph to check the position of the needle.

Thus, there is a need for an apparatus which provides increased accuracy of needle placement, thereby reducing the duration of the procedure and minimizing the radiation to which the patient is exposed.

There is also a need for an apparatus which can shorten the time required to retrieve a tissue sample and thereby reduce the expense and discomfort associated with the procedure.

There is a further need for an apparatus which can be introduced into the tomograph with the patient to verify correct location of the biopsy needle with respect to the target tissue.

Yet another disadvantage of known prior art guidance devices is that while such devices are capable of directing the biopsy needle along a desired path, they do not control the location of the needle along that path, that is, the devices do not control the depth of penetration of the biopsy needle. Thus, it is possible for the biopsy needle to be directed along the proper path but for the needle tip to be directed to a location either proximal or distal to the target tissue. Not only can improper penetration depth result in failure to direct the biopsy needle to the target tissue to obtain a tissue specimen, but also accidental overpenetration can result in laceration or perforation of organs or vessels lying distal to the target tissue.

Thus, there is a need for an apparatus which not only directs the biopsy needle along the desired path but also controls the depth of penetration of the needle to prevent accidental overpenetration of the needle.

Still further problems arise with known prior art guidance devices when the skin entry point and the target tissue do not lie in the same axial slice. Known prior art guidance devices are limited to directing the needle in an axial plane, that is, in a plane normal to the longitudinal axis of the patient. Thus, where the optimum needle path lies in a plane which is oblique to the longitudinal axis of the patient, the guidance device cannot be used. The physician must resort to guidance of the biopsy needle by hand, with the attendant problems and disadvantages previously discussed.

Thus, there is a need for a guidance device which is not limited to directing a biopsy needle along a path which lies in a plane normal to the longitudinal axis of the patient.

SUMMARY OF THE INVENTION

Stated generally, the present invention relates to an improved apparatus for guiding a tissue sampling device to a target location within the body of a patient. The apparatus permits accurate and easy retrieval of acceptable tissue specimens from locations within the body of a patient which require angling of the needle to reach the target tissue. The apparatus permits accurate and easy guidance of the biopsy needle to even small pathological changes, and the apparatus can be introduced into the tomograph with the patient to verify correct location of the biopsy needle with respect to the target tissue. The apparatus not only directs the biopsy needle along the desired path but also controls the depth of penetration of the needle to prevent accidental overpenetration of the needle. Furthermore, the guidance device is not limited to directing the needle along a path lying in a plane normal to the longitudinal axis of the patient but is capable of guiding the needle in a plane which is oblique to the longitudinal axis.

Stated somewhat more specifically, the present invention comprises an apparatus for guiding a puncture instrument through an entry point in the body of a patient to a target location within the body of the patient. The apparatus comprises a support means for establishing a fixed reference point adjacent to said body of said patient. A path determining means is mounted to the support means and is adjustable to define a path through the entry point in a predetermined direction. An instrument holding means mounted to the path determining means holds a puncture instrument and moves the puncture instrument along the path defined by the path determining means. A depth determining means operatively associated with the path determining means limits the extent of the movement of the puncture instrument along its path such that the puncture instrument penetrates the patient's body only to a predetermined depth.

In the disclosed embodiment, the puncture guiding apparatus further includes an instrument guide means operatively associated with the path determining means for guiding the puncture instrument as the puncture instrument is moved along the path defined by the path determining means. The instrument guide means of the disclosed embodiment automatically disengages from the puncture instrument when the puncture instrument reaches the limit of its movement. In one embodiment, the instrument guide means comprises a pair of cooperating jaws mounted to the path determining means. The jaws disengage from the puncture instrument when the puncture instrument reaches the limit of its movement. In a more particular embodiment, the pair of cooperating jaws are pivotably mounted to the path determining means for articulation in a horizontal plane. Both of the jaws pivotably disengage from the puncture instrument when the puncture instrument reaches the limit of its movement. In another embodiment, one of the pair of cooperating jaws is pivotably mounted to the path determining means for articulation in a vertical plane. The vertically articulating jaw pivotably disengages from the puncture instrument when the puncture instrument reaches the limit of its movement. Advantageously, the instrument guide means is removably mounted to the path determining means.

In another aspect of the invention, a recoil suppression means is operatively associated with the depth determining means and captures the puncture instrument when the puncture instrument reaches the limit of its movement to prevent the puncture instrument from recoiling.

In yet another aspect of the invention, the patient lies on a support surface. The support means for establishing a fixed reference point adjacent to said body of said patient comprises a track mounted to the support surface. A carriage is movably mounted to the track, and a support arm is mounted to the carriage, with the path determining means being mounted to the support arm. Advantageously, the track comprises a curved upper surface for minimizing artifacts when the puncture guidance apparatus is used in conjunction with imaging technology.

Thus, it is an object of the present invention to provide an improved apparatus for guiding a tissue sampling device to a target location within the body of a patient.

It is another object of the present invention to provide an apparatus which permits accurate and easy retrieval of acceptable tissue specimens from locations within the body of a patient which require angling of the needle to reach the target tissue.

Another object of the present invention is to provide an apparatus which permits accurate and easy retrieval of tissue specimens from even small pathological changes.

Still another object of the present invention is to provide an apparatus which can be introduced into the tomograph with the patient to verify correct location of the biopsy needle with respect to the target tissue.

It is yet another object of the present invention to provide an apparatus which not only directs the biopsy needle along the desired path but also controls the depth of penetration of the needle to prevent accidental overpenetration of the needle.

A further object of the present invention is to provide a guidance device which is not limited to a plane normal to the longitudinal axis of the patient but which can direct a biopsy needle along a path lying in a plane oblique to the longitudinal axis of the patient.

Other objects, features, and advantages of the present invention will become apparent upon reading the following specification, when taken in conjunction with the drawings and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a puncture guidance device according to the present invention.

FIG. 2 is a side cutaway view of the carriage and track of the puncture guidance device of FIG. 1.

FIG. 3 is an exploded view of the carriage, support arm, path determiner, instrument holder, and puncture instrument of the guidance device of FIG. 1.

FIG. 4 is a front view of the path determiner of the puncture guidance device of FIG. 1.

FIG. 5 is a top view of the path determiner of FIG. 4.

FIG. 6 is a side view of the path determiner of FIG. 4 partially cut away to reveal interior detail.

FIG. 7 is a side view of the path determiner of FIG. 4 with a tissue sampling instrument mounted thereto.

FIG. 8A is a bottom view of a needle guide of the puncture guidance device of FIG. 1 showing the jaws of the needle guide opened.

FIG. 8B is a bottom view of the needle guide of FIG. 8A showing the jaws of the needle guide closed.

FIG. 8C is a side view of the needle guide of FIG. 8A.

FIG. 8D is a front view of the needle guide of FIG. 8A with the jaws of the needle guide closed.

FIG. 8E is a top view of the needle guide of FIG. 8A with the jaws of the needle guide closed.

FIG. 9 is a perspective view of the mounting arrangement by which the needle guide is mounted to the path determiner.

FIGS. 10A-C are side, front, and top views, respectively, of the needle guide and path determiner showing the jaws of the needle guide in the closed position.

FIGS. 11A-C are side, front, and top views, respectively, of the needle guide and path determiner showing the jaws of the needle guide in the opened position.

FIG. 12 is a perspective view of the puncture guidance device of FIG. 1 mounted to a patient table of a computer tomograph with a patient lying on his back on the patient table.

FIG. 13 is an axial plane view transverse to the longitudinal axis of a patient showing the puncture guidance device of FIG. 1 directing the needle of a tissue sampling instrument to a target location within the body of the patient.

FIG. 14 is a perspective view of an alternate embodiment of a needle guide for use with the puncture guidance device of FIG. 1.

FIG. 15 is a top view of the path determiner showing the needle guide of FIG. 14 mounted thereto.

FIG. 16 is a side view of the path determiner with tissue sampling device mounted thereto and having the needle guide of FIG. 14 mounted thereto, the jaws of the needle guide being in the closed position, and the needle guide being cut away to reveal interior detail.

FIG. 17 is a side view of the structure of FIG. 16 with the jaws of the needle guide being in the open position.

DETAILED DESCRIPTION OF THE DISCLOSED EMBODIMENT

Referring now to the drawings, in which like numerals indicate like elements throughout the several views, FIG. 1 discloses a puncture guidance device 10 according to the present invention. The puncture guide 10 comprises a base 12 having an elongated track 14 thereon, a carriage 16 movable along the track, a support arm 18 mounted to the carriage, and a path determiner 20 movably mounted to the support arm. Each of these components will now be discussed in more detail.

The base 12 is mounted to the patient table 22 of the computer tomograph. The base 12 includes a concave back plate 24 which is disposed generally beneath the portion of the patient from which a tissue specimen is desired. The track 14 runs the length of the base 12 along one lateral edge 26 thereof. The track 14 is generally T-shaped and defines opposing channels 28a, 28b. The upper surface 30 of the track 14 is convex. Preferably the track 14 is comprised of a microcellular polyurethane plastic or other material which exhibits low-attenuation for the used radiation. This plastic is suitable for computer tomography and MNR-tomography.

As can perhaps best be seen in FIG. 3, the carriage 16 is on its bottom provided with a groove 32 comprising a pair of opposing, mutually facing L-shaped profiles 34a, 34b. Referring again to FIG. 2, the inwardly extending legs of the L-shaped profiles 34a, 34b of the carriage 16 engage the channels 28a, 28b of the track 14 such that the carriage is longitudinally slidable on the track. The carriage 16 further includes a locking pin 38 rotatably mounted within the carriage generally transverse to the direction of elongation of the track 14. The locking pin 38 has a concave recess 39 formed therein conforming generally to the convex curvature of the upper surface 30 of the track 14. When the locking pin 38 is pivoted to rotate the recess 39 into alignment with the upper surface 30 of the track 14, the carriage 16 is freely displaceable along the length of the track. When the locking pin 38 is pivoted to rotate the recess 39 away from the upper surface 30 of the track 14, as depicted in FIG. 2, the shank of the locking pin is brought into interfering engagement with the upper surface of the track and locks the carriage 16 with respect to the track.

Re