GB2184358A

GB2184358A - Guide for directing a probe to a target site in a body

Info

Publication number: GB2184358A
Application number: GB08627517A
Authority: GB
Inventors: Helmi Boutros
Original assignee: Karl Storz SE and Co KG
Current assignee: Karl Storz SE and Co KG
Priority date: 1985-11-20
Filing date: 1986-11-18
Publication date: 1987-06-24
Also published as: IT1198128B; FR2590153A1; IT8622398A0; FR2590153B1; DE3639211A1; CN86108407A; GB8627517D0

Abstract

Instrument for fixing the direction of the needle during puncturing an internal organ of the human body. It comprises two spindles (1, 2) which are interconnected at one point. On each of these spindles is fixed a plane, which can revolve freely about its axis. One of the planes has several portion (4, 5), which slide over one another and make it possible to modify the surface as required. Each plate is provided with a system of slots (6, 7) and screws (8, 9) making it possible for each spindle to slide on the particular plate and remains on the same plane as the latter. During use, the instrument is particularly suitable for fixing the direction of the needle during the puncturing of a kidney calix during percutaneous nephrolithotomy. <IMAGE>

Description

SPECIFICATION Guide for directing a probe to a target site in a body The present invention relates to a guide for directing a probe to a target site in a body and has particular relevance to determining the proper direction of advance and position of the needle during the puncture of an internal organ of the human body, particularly the puncture of the kidney calices during a percutaneous litholapaxy.

Normally when puncturing a particular kidney calix, the surgeon follows the needle on a continuous basis on an observation screen, changing between the front and side view and modifying the direction of the needle whenever this is necessary.

This method has risks for the patient, particularly as a result of an incorrect guidance of the puncture needle, excessively long X-radiation exposure and an extension of the operating time.

The disadvantages are eliminated when using a device as illustrated hereinafter, in that it accurately and rapidly determines the axis along which the puncture needle must be oriented, together with the distance required by the needle to reach the calix.

The present invention provides an instrument serving as a guide for directing a probe to a target site in a body and comprising means defining a first plane, means defining a second plane intersecting the first plane, and means defining the line of intersection of said planes, said plane defining means each also defining an edge line lying in the respective plane, which edge lines intersect, and each of which may be brought to lie against a patient's body, the angle of intersection of said edge lines being adjustable.

The necessary principle is based on determining the puncture axis, which is in fact formed by the intersection of two planes and will be illustrated with reference to litholapaxy.

When a patient's body is subjected to X-ray examination using first a ray path from front to back and then a ray path from side to side, the first plane is parallel to the X-rays from the front (vertical rays) passing through a line determined by the puncture point and a point which is rendered visible with the aid of an observation instrument in front view and represents the frontal projection of the calix sighted on the surface of the patient's body.

The second plane runs parallel to the lateral X-rays (horizontal rays) and passes through a line determined by the puncture point and a point rendered visible with the aid of an observation instrument in side view and represents the lateral projection of the calix sighted on the surface of the patient's body. The intersection of these two planes forms the sought axis, which is rendered visible on the instrument. Referring to a preferred example according to the invention, the instrument has two spindles interconnected at one of their end points by a system permitting a fixed angle during use. Throughout the remainder of the description these two spindles are referred to as spindles 1 and 2. A plate is fixed along each spindle, representing a plane parallel to the spindle and which passes through the same. Of these plates, plate 1 is fixed to spindle 1 and plate 2 to spindle 2.Each plate is connected to the particular spindle by a system permitting two types of movement, namely the spindle must slide on the plate surface, always being in contact and parallel thereto and the plate must rotate freely about the spindle.

The shape of each of plate is such that it does no impede the rotary movement about the particular spindle. Plate 2 comprises several parts, which are interconnected by a system, so that the different parts of the plate slide above one another, whilst always remaining on the same plane. Thus, the surface of the plate is modified at random. The shape of the different parts of plate two must on the one hand not impair the rotary movement thereof about its axis or spindle and must on the other hand enable plates 1 and 2 to form a straight line, when they come into contact with one another.

In a preferred embodiment, the two spindles are interconnected by a ball joint.

Plate 1, which has the shape of a circular portion with 1800, is fixed to spindle 1. Plate 2 is fixed to spindle 2 and is formed from two circular parts which slide over one another. The two parts of plate 2 are provided with a system enabling same to be fixed to one another in the desired position.

Thus, the two parts of plate 2 together form a circular part, which has a variable angle and which can open up to 1800. Spindle 2 is fixed to plate 2 by a system, so that the plate slides on the spindle, remaining in contact therewith and moving parallel thereto.

In a variant of the previously described embodiment, spindle 1 is installed in the centre of plate 1 and is represented by a straight line drawn on plate 1 from the centre of the diameter to the centre of the arc. Spindle 2 is connected to the outermost end of the line representing spindle 1, i.e. to the point which is at half the distance to the linear part. This connection is achieved with the aid of a system of ball joints, so that spindle 2 can move freely on spindle 1. The ball joint must take up a minimum amount of space. It is fixed to one of the front sides of plate 1 and spindle 2 follows the movements of the ball joint. It is aligned with the side facing that to which the ball joint is fixed.A recess, whose diameter is the diameter of said spindle, is provided level with the point located at half the distance of the linear line of plate 1 and which permits the passage of spindle 2 on the plane of plate 1.

Plate 2 is formed by two flat bolts or pins, which are connected to spindle 2. The connection is as close as possible to the intersection of the two spindles, i.e. at a point at half the distance of the plate 1.

These two bolts can open out like a fan.

The connection of the bolts to spindle 2 is such that the two bolts, together with spindle 2 are necessarily located on the same plane, independently of the position of spindle 2 or the bolts forming plate 2. In other words plate 2, which is here formed from two bolts, as well as spindle 2 are always located on the same plane.

In the closed position the two bolts form plate 2 superimposing spindle 2, whilst in the open position the two bolts form a circular portion. The angle formed by the two bolts is variable and can open to 1800. The connection of the two bolts to spindle 2 is provided by a system making it possible to set it to the desired angle during use.

One of the two bolts of plate 2 is provided at its unconnected end with a fixing system making it possible to fix it to the curved part of plate 1 when in contact therewith. Both in its curved part and in its linear part, plate 1 is graduated in degrees.

In another variant of the instrument, the handle interconnects the two spindles at the free end thereof and is used for securing the instrument during use.

USE OF THE SIGHTING INSTRUMENT The patient lies with 3/4 of the stomach flat on the operating table. The observation instrument (brightness amplifier) is set up in such a way that successively front and side views can be taken.

By setting the observation instrument to "front side" (in this case the X-rays strike vertically), a line is fixed on the surface of the patient's body connecting two points, namely the puncture point and the projecting of the front side of the highest point of the sighted calix on the patient's body. This line is drawn on the surface of the patient's body using a felt tip pen.

The observation instrument is then set to the "side view" position (the X-rays now strike horizontally). On the surface of the patient's body is now placed a line connecting two points, namely the puncture point and the projection of the side view of the highest point of the cited calix on the patient's body.

This line is located on the surface of the patient's body. The two drawn lines meet at the puncture point.

The sighting instrument is set up in the following way. Spindle 1 is kept parallel with the X-rays in the "front view" position (i.e. vertically in this case). Spindle 2 must be kept parallel with the X-rays in the "side view" position (i.e. in this case horizontally).

Plate 1 is rotated about its axis until its disk is aligned with the line drawn from the front.

Plate 2 is rotated about its axis and the apeture of its angle is varied until its disk is aligned with the line drawn from the side.

The different parts of plate 2 slide over one another (whilst keeping spindle 2 parallel to the lateral X-rays) up to contact with plate 1.

The-two plates come together on a line, which gives the direction of the puncture needle. Thus, the latter slides along the intersection of the two plates.

A radioscopic check is necessary at the end of puncture to ensure that the needle has reached the sighted calix.

The attached drawings illustrate the operation.

Figure 1 shows the instrument during the operation.

Figure 2 shows a variant of this instrument.

Figure 3 shows the setting of the instrument on the patient.

Figure 4 shows the scale graduations drawn on the instrument plate 1.

The instrument shown in Fig. 1 comprises two spindles and two plates. Spindle 2 (1) having a length of 12 cm is connected at one of its ends to spindle 2 (2), which has the same length. The angle formed by the two spindles is 900.

Plate 1 (3) is fixed to spindle 1 (1) and has the shape of a circular portion of 1800 and has a radius of 11 cm. Plate 1 (3) contains two circular slots 6, which run parallel to the arc thereof. Within each slot is guided a screw, which is fixed by a nut to the plate.

Level with the plate, the screw heads have a bore for the passage of spindle 1 (3).

Plate 2 (2) comprises two facing parts. Each is a circular portion with a radius of 11 cm and an angle of 1100. Each circular portion contains two slots in the form of an arc running parallel with the curvature thereof.

Within each slot is guided a screw 9, which is fixed by a nut and the two parts 4 and 5.

Spindle 2 (2) passes through the screw heads level with plate 2 (4 and 5).

A safety lug 10 is fixed to the end of spindle 1 (1) and prevents sliding down thereof from the screw heads. The end of spindle 2 (2) is secured by an identical lug 11.

In the embodiment according to Fig. 2 the instrument comprises a plate 3 in semicircular form. A line 1 drawn on this plate and which subdivides it into quadrants, represents the axis corresponding to this plate. A recess 15 in the vicinity of the centre of the circle of the plate makes it possible to fit a ball joint 14, which is fixed to the plate.

Spindle 2 is connected in positively engaging manner with the ball joint and follows the movements thereof. On the latter two bolts 12, 13 are connected to the ball joint through a screw system on the plane. The two bolts 12, 13, together with spindle 2 always form a plane.

Fig. 3 shows the position of the instrument on the patient.

Fig. 4 shows the scale graduations, indicated on the plate with 1800. These are scale graduations in mm and cm on the linear part and in degrees on the curved part. Straight lines 16 are drawn from the point at half the distance of the linear part, in order to meet the scale graduations on the curved part.

Other lines 17 are drawn from the linear and vertical part thereto.

During use the instrument is particularly suitable for determining the direction of the needle during the puncture of the kidney calix in the case of percutaneous nephrolitholotomy.

Claims

1. An instrument serving as a guide for directing a probe to a target site in a body and comprising means defining a first plane, means defining a second plane intersecting the first plane, and means defining the line of intersection of said planes, said plane defining means each also defining an edge line lying in the respective plane, which edge lines intersect, and each of which may be brought to lie against a patient's body, the angle of intersection of said edge lines being adjustable.

2. An instrument as claimed in Claim 1, wherein the means defining the first plane is a plate, one edge of which defines the respective edge line.

3. An instrument as claimed in Claim 2, wherein the means defining the second plane comprises a pair of members mounted to pivot fanwise to vary the angle included between intersecting edges thereof.

4. An instrument as claimed in Claim 3, wherein said pair of members are each a plate, which plates overlap to a variable extent in said fanwise pivoting.

5. An instrument as claimed in Claim 3, wherein said pair of members are a pair of elongate members pivoted together at ends thereof.

6. An instrument as claimed in any preceding claim wherein said means defining first and second planes are adjustable to vary the angle between said planes.

7. An instrument as claimed in Claim 6, wherein said means defining a first plane and said means defining a second plane are interconnected by a ball joint.

8. An instrument as claimed in any preceding claim wherein at least one of said plane defining means includes a generally linear member or marker extending in the respective plane from a common point on the intersection line of said planes.

9. An instrument as claimed in Claim 8, wherein said linear member or marker of one or both of said plane defining means extends on a centre line about which said means is generally symmetrical, or is adjustable to lie on such a line.

10. An instrument as claimed in any preceding claim, including means for locking the means defining the intersection of the planes in a chosen fixed position.

11. An instrument for establishing the puncture axis required during the puncture of a kidney calix substantially as hereinbefore described with reference to and as illustrated in Figs. 1, 3 and 4 or Figs. 2 and 4.

12. Instrument in order to establish the puncture axis during puncture of a kidney calix, characterized in that it has two spindles, which are fixed to one another at one of the ends thereof, whereby to each of said spindles is fixed a rigid plane, which runs parallel to the spindle and which revolves freely about the same.

13. Instrument according to claim 12, characterized in that one of the planes is formed by several circular portions sliding above one another in order to form a circular portion with a variable angle, which can open up to 1800, the different parts being setable to the desired angle.

14. Instrument according to claim 12, characterized in that one of the planes comprises a part having the shape of a circular portion of 1 800

15. Instrument according to claim 12, characterized in that the two axes are interconnected by a ball joint system.

16. Instrument according to claims 12, 14 and 15 characterized in that one of the two planes is formed by two flat bolts, connected to the corresponding spindle level with the connection thereof to the ball joint and which open out in fan-like manner in order to adapt to the second plane formed by a circular portion of 1800, whereby one of the bolts is provided at its free end with a fixing system, which fixes same to the curvature of the second plane on contact therewith.

17. Instrument according to claims 12 and 16 characterized in that one of the spindles is fitted in the centre of the particular plate having the shape of a circular portion with an angle of 180 , the spindle being formed by a line drawn on the plate and meeting a point which is located at half the distance of the linear portion and the point on half the distance from the curved portion of the plate.

18. Instrument according to claims 12, 14, 15 and 17, characterized in that a ball joint is fixed to the plate at the intersection of the two spindles, whereby at this point a recess is provided on the plate for the passage of the spindle and is positively connected to the ball joint.

19. Instrument according to claim 16 characterized in that it has a fixing system with two bolts and forms one of the planes for fixing it at a particular angle.

20. Instrument according to claims 12 and 14 characterized in that the plate in the form of a circular portion of 180 is provided with scale graduations on its curved and linear portions.

21. Instrument according to claim 12, characterized in that a grip interconnects the two free ends of the two spindles.