MEDICAL INSTRUMENT FOR TAKING TISSUE SAMPLES IN THE BODY

Abstract

Medical instrument for taking a tissue sample in the body, the instrument includes an inner tube and an outer tube mounted axially slideable over the inner tube. The inner tube possesses a distal end with a cutting spiral and a proximal end to turn the spiral in the tissue to be sampled. The outer tube possesses a distal end with a cutting edge to cut loose the tissue in the spiral by sliding the outer tube over the spiral. Both tubes over at least an overlapping axial length of 30 cm are executed flexibly bendable because over said length the tubes are provided with one or more grooves which extend through the wall of the tubes and which open upon torsion in one direction.

Claims

1. A medical instrument for taking a tissue sample in the body, the instrument is composed of at least two tubes which fit into each other, respectively an inner tube and an outer tube, the inner tube being slideably and rotatably mounted in the outer tube, whereby the inner tube possesses a distal end which in its extension is provided with a cutting and rotationally penetrating spiral and a proximal end to turn the spiral in the tissue to be sampled and the outer tube possesses a distal end with a cutting edge to cut loose the tissue in the spiral by sliding the outer tube over the spiral, wherein both tubes (2, 3) over at least an overlapping axial length of 30 cm are executed flexibly bendable because over the length the tubes (2, 3) are provided with one or more grooves which extend through the wall of the tubes (2, 3) and which open upon torsion in one direction and thus increase the bendability relative to the resting position without torsion and close upon torsion in the other direction, such that the torsional rigidity is maximal or increases to a maximum with an increasing torsional force for drawing the cutting spiral like a cork screw into the tissue to be sampled upon rotation of the spiral.

2. The medical instrument according to claim 1, wherein the overlapping flexible lengths the groove pattern in both tubes (2, 3) is such that in the lengths the flexibility of both tubes is equal.

3. The medical instrument according to claim 1, wherein the overlapping flexible lengths the groove pattern in both tubes is similar.

4. The medical instrument according to claim 1, wherein there are two or more parallel primary grooves which are uniformly distributed over a contour of the tubes and which in an axial direction enclose an acute angle which is less than 45°.

5. The medical instrument according to claim 1, wherein the tubes show a rigid section without the grooves at the proximal end of the instrument.

6. The medical instrument according to claim 1, wherein both tubes are provided with at least one spiral-shaped primary groove which extends in one or more windings or a section of a winding along the contour of the tubes (2, 3).

7. The medical instrument according to claim 1, wherein both tubes are provided with at least one groove which is composed of a primary longitudinal groove and secondary grooves grafted thereon which extend on both sides of the primary groove.

8. The medical instrument according to claim 6, wherein both tubes are provided with at least one primary groove which is spiral-shaped and runs over equal lengths and with the same pitch in both tubes.

9. The medical instrument according to claim 7, wherein both tubes contain one or more sinus-shaped secondary grooves which extend alternatingly on both sides of a primary groove in overlapping lengths of both tubes.

10. The medical instrument according to claim 7, wherein at least one secondary groove is a block-shaped groove which extends alternatingly on both sides of a primary groove with sections departing from the primary groove perpendicular to the primary groove and which are connected by sections at a distance from the primary groove in both tubes simultaneously.

11. The medical instrument according to claim 7, wherein both tubes contain one or more toothed secondary grooves in the overlapping lengths which on one side or alternatingly on both sides of the primary groove can extend with V-shaped sections which with their legs extend from the primary groove and whose tips point away from the primary groove, alternatingly to this and the other side of the primary groove.

12. The medical instrument according to claim 11, wherein the V-shaped sections have a long leg and a short leg, whereby the short leg is perpendicular to the primary groove and the long leg encloses an acute angle with the primary groove.

13. The medical instrument according to claim 11, wherein the V-shaped sections are uniform and with their acute angle are oriented to the same end of the instrument.

14. The medical instrument according to claim 1, wherein a width of the grooves is less than a few hundreds of a millimetre.

15. The medical instrument according to claim 1, wherein an outer diameter of the outer tube of the instrument is less than 2.5 mm.

16. The medical instrument according to claim 1, wherein the tubes with one or more grooves are made from elastic medical stainless steel.

17. The medical instrument according to claim 7, wherein both tubes are provided with at least one primary groove which is spiral-shaped and runs over equal lengths and with the same pitch in both tubes.

18. The medical instrument according to claim 8, wherein both tubes contain one or more sinus-shaped secondary grooves which extend alternatingly on both sides of a primary groove in overlapping lengths of both tubes.

19. The medical instrument according to claim 8, wherein at least one secondary groove is a block-shaped groove which extends alternatingly on both sides of a primary groove with sections departing from the primary groove perpendicular to the primary groove and which are connected by sections at a distance from the primary groove in both tubes simultaneously.

20. The medical instrument according to claim 8, wherein both tubes contain one or more toothed secondary grooves in the overlapping lengths which on one side or alternatingly on both sides of the primary groove can extend with V-shaped sections which with their legs extend from the primary groove and whose tips point away from the primary groove, alternatingly to this and the other side of the primary groove.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0039] With the intention of better showing the characteristics of the present disclosure, a few embodiments of a medical instrument according to the present disclosure for taking tissue samples in the body are described hereinafter by way of an example, without any limiting nature, with reference to the accompanying figures, wherein:

[0040] FIG. 1 schematically shows a view of a medical instrument according to the present disclosure;

[0041] FIG. 2 shows the section of the instrument indicated in FIG. 1 with F2 and this in a resting position;

[0042] FIG. 3 shows a cross-section according to line III-III in FIG. 2;

[0043] FIG. 4 shows an alternative embodiment according to the cross-section of FIG. 3;

[0044] FIG. 5 on a larger scale shows the section indicated in FIG. 2 with the frame F5 but for an alternative embodiment of the present disclosure;

[0045] FIG. 6 shows the section of FIG. 5 but in another condition under torsional load, whereby the effect of the torsional load can be observed in the primary and subsidiary grooves;

[0046] FIG. 7 shows a variant of FIG. 5;

[0047] FIG. 8 shows another variant of FIG. 5 in the resting condition;

[0048] FIG. 9 shows the section of FIG. 8 under torsional load;

[0049] FIG. 10 shows still another variant of FIG. 5 in the resting condition;

[0050] FIG. 11 shows still another variant of FIG. 5 in the resting condition; and

[0051] FIG. 12 shows the section of FIG. 11 under torsional load.

DETAILED DESCRIPTION

[0052] The instrument 1 of FIG. 1 shown by way of example is an instrument for taking a tissue sample in a patient's body.

[0053] The figures are not to scale and are shown out of proportion to better express the dimensional and formal design characteristics.

[0054] The instrument 1 is flexibly executed over at least a part C of its length and possesses an outer diameter A which is sufficiently small to be able to fit in a working channel of, for example, less than 2 mm of an endoscope or the like and which must be bendable in curves to, for example, penetrate via the airways into the lungs to locally take a tissue sample there.

[0055] The instrument 1 is composed of an outer tube 2 and an inner tube 3 which is slideably and rotatably mounted in the outer tube 2, whereby the outer diameter D of the inner part 3 is slightly smaller than the inner diameter of the outer tube 2 which serves as a kind of sheath for the guidance of the inner tube 3.

[0056] In some embodiments, the tubes 2 and 3 are made of a medical stainless steel or another suitable metal.

[0057] At the distal end 4 and in the extension thereof, the inner tube 3 is provided with a cutting and rotationally penetrating spiral 5 for taking a tissue sample.

[0058] At its proximal end 6 over a certain length B, the inner tube 3 is rigidly executed to form a sort of handle with which the inner tube 3 can be rotated in to turn the spiral 5 around its shaft in the tissue to be sampled and with which the spiral 5 can be held while the outer tube 3 can be axially moved over the spiral to cut loose the tissue that is grabbed by the spiral 5, for which purpose the outer tube is provided with a cutting edge 7 at the distal end. Alternatively the outer tube 2 can be rotated over the spiral 5 to cut off the tissue.

[0059] Subsequently, the instrument 1 can be withdrawn from the body to recover the tissue sample.

[0060] The section 8 with length C between the rigid proximal end 6 of the inner tube 3 and the spiral 5 is flexibly executed because in the case of FIG. 2 said section is provided with a cut straight through the wall 9 of the inner tube 3 to form a spiral-shaped or sinus-shaped primary groove 10 which extends along the contour and over the entire length C of the flexible part 8 or over a section of said length C, in this case with one and a half winding. The direction of rotation of the spiral-shaped groove is the reverse to the direction of rotation of the spiral-shaped tool.

[0061] The primary groove 10 mostly extends in axial direction, more than in lateral direction, whereby the primary groove in the axial direction X-X′ encloses an acute angle S which is less than 45°, less than 30°, or less than 15°.

[0062] In some embodiments, the cut is a fine cut with a width E of for example one hundredth of a mm which for example is made with a laser.

[0063] The groove 10 forms a device that ensures, when exercising a torsional force T on the proximal end 6 in the opposite direction of rotation of the spiral-shaped groove 10, the groove 10 closes, such that the torsional rigidity increases and is sufficient to turn the spiral-shaped tool 5 into the tissue.

[0064] When exercising a torsional force T′ in the opposite direction of rotation the groove 10 opens, such that the whole assembly becomes less rigid and the bend flexibility increases, to be able to withdraw the inner tube 3 in the outer tube 2 when the instrument 1 is inserted with one or more curves in the patient's body by an endoscope or the like.

[0065] Analogously, the outer tube 2 in the overlapping flexible section 8′ is provided with a primary groove 10.

[0066] In some embodiments, the grooves 10 in the flexible sections 8 and 8′ are aligned such that they result in a similar flexibility of both tubes 2 and 3 in said flexible sections.

[0067] The flexible sections 8, 8′ can also be provided with two or more parallel grooves 10 which are uniformly distributed over the contour and thus for example in the case of two grooves 10 are located diametrically opposite each other as shown in FIG. 4 or in the case four grooves 10 are rotated over an angle of 90°. Consequently the flexibility is increased even more relative to one single groove 10.

[0068] FIG. 5 shows an example of a groove 10 which is composed of a spiral-shaped primary groove 10a and a sinus-shaped secondary groove 10b grafted thereon formed by a sinus-shaped cut which extends on both sides of the primary cut 10a, said sinus showing an amplitude H and extending over an axial length L of the flexible section 8.

[0069] When rotating the rigid proximal end 6 in one direction of rotation the cut closes as shown in FIG. 5 while the flexible section 8 becomes longer and thinner with a smaller outer diameter D.

[0070] In case of a rotation in the opposite direction of rotation the groove 10 opens as shown in FIG. 6 (schematically strongly exaggerated).

[0071] In FIG. 5, the torsional rigidity and the bend rigidity are maximal, while in FIG. 6 the flexibility has increased.

[0072] The sinus-shaped groove 10b ensures a flexible bend in both directions of the axis X-X′.

[0073] FIG. 7 shows a variant of a sinus-shaped groove 10b with a greater amplitude H, whereby the groove 10b extends in circumferential direction in this case over a zone that is greater than half the contour of the inner tube 3.

[0074] FIG. 8 shows yet another example of a secondary groove 10b which in this case is executed as a block shape and is realised by a cut with U-shaped sections which extend alternatingly on both sides of the primary groove 10a with parallel legs 10′ which depart from the primary groove 10a and extend perpendicularly to said groove 10a and which are connected by sections 10″ at a distance from the groove 10a.

[0075] In this way straight block-shaped teeth 11 are cut out as it were which fit in rectangular recesses 12, obtained by the U-shaped cuts 10′-10″ in the wall 9 of the tubular inner tube 2.

[0076] In terms of opening and closing upon torsion, the behaviour of the inner tube 3 is analogue as the aforementioned embodiment, whereby FIG. 8 illustrates the condition upon torsion in one direction with closed groove 10 and FIG. 9 shows the condition upon torsion in the other direction with an open groove 10.

[0077] FIG. 10 shows an embodiment of a tube with small teeth 11. If the teeth 11 are smaller than the width of the groove 10 when the groove 10 opens a gradual effect can be obtained when the groove 10 opens because the teeth on one side of the line X-X′ are than staggered relative to the recesses on the other side of the line X-X′.

[0078] In this way the flexibility and the torsional rigidity can also be gradually maintained, also when the torsional force falls away.

[0079] Such small toothing 11 can for example also be superimposed on the sinusoidal cut of FIG. 6.

[0080] Yet another type of groove is shown in FIG. 11, in which a toothed secondary groove 10b is shown which is obtained by a cut with V-shaped sections to form oblique teeth 11 which extend like a sort of sawtooth toothing on one side of a spiral-shaped primary cut 10a and whose tip 13 points away from the primary groove 10a.

[0081] In the example shown of FIG. 11 the V-shaped sections of the groove 10 have a short leg 10K which is perpendicular to the primary groove 10a and a long leg 10L which encloses an acute angle F with the primary groove 10a.

[0082] The groove 10 is continuously cut such that the V-shaped sections with said acute angle F point in the same direction of a same end, for example with the tip 14 in the direction of the end 4 with the spiral 5.

[0083] In this case, when exercising a torsion in one direction, the rotation will occur flexibly thanks to the oblique cut formed by the long leg 10L, but in the event of a torsion in the other direction, the rotation will be abruptly blocked by the straight angle of the teeth 11 formed by the short leg 10K engaging with the recesses 12.

[0084] Depending on the direction in which the acute angle F is oriented, in the event of a rotation either the transmitted torsional torque at a maximum value will be maintained at a constant fixed and desired value, or the flexibility will be maintained.

[0085] Thus, the tool can, for example, be safeguarded from an overload in case of use that could break or damage the tool 5.

[0086] The outer tube 2 can also be made from elastic medical stainless steel and will be executed with one or more primary grooves with which the flexibility and the torsional rigidity can be locally influenced by a torsion in the one or other direction simultaneously and paired with the inner tube.

[0087] It is also not excluded that the grooves 10 extend over the entire length B of the flexible part 8, but that in this part 8 shorter grooves are applied which, for example overlap each other lengthways or are positioned in a staggered way such that a variable flexion/torsion is possible.

[0088] Different types of grooves 10 can also be combined on the same tube 2 or 3. The sort of grooves is also not restricted to the type as described above.

[0089] In some embodiments, the grooves 10 are such that both tubes 2 and 3 in overlapping flexible zones yield the same flexibility, because the groove pattern is uniformly distributed or similar or even identical, but laterally shifted in the circumferential direction of the tubes 2 and 3.

[0090] The present disclosure is by not limited to the embodiments described as an example and shown in the drawings, but a medical instrument according to the present disclosure for performing a medical procedure in the body can be realised in all kinds of forms and dimensions, without departing from the scope of the present disclosure.