BIOPSY DEVICE

Abstract: A biopsy device comprising a hollow body (2) inside which a plunger (3) is slidable, a mandrel (8) being fixed at one end of said plunger (3), said plunger (3) being slidable between a first rearward position and a second forward position with respect to said hollow body (2), said plunger (3) being associated with return means (9) suitable for producing an automatic movement of said plunger (3) from said forward position to said rearward position, characterized in that it comprises cannula means (13) slidably coupled with said mandrel (8), support means (10), connected to said hollow body (2), for supporting said cannula means (13), said support means (10) comprising sliding means (12) suitable for causing said cannula means (13) to slide between a first operating position and a second operating position.

Description: Biopsy device The present invention concerns a biopsy device, i.e. a device for collecting samples of organic material from a patient body. From patent EP0076239 a syringe is known for hypodermic biopsy, said syringe being provided with automatic plunger return, and using a hypodermic needle; the syringe comprises a syringe body consisting of two coaxial cylindrical elements, one internal and the other external, integrally mutually joined at the front end of the syringe body from which said elements protrude in a seat having a shape of a frustum, the seat being crossed by a through hole coaxial with the two cylindrical elements and a hypodermic needle being insertable in the seat; the two coaxial cylindrical elements internally define a first annular chamber, closed at the front end of the syringe body and open at the other end; a cylindrical cavity is centrally arranged inside the internal cylindrical element, said chamber being open at both ends thereof and ending with a portion having a shape of a frustum communicating with said seat having a shape of a frustum; the syringe body houses an axially movable plunger consisting of two coaxial cylinders, one internal and the other external, defining therebetween a second annular chamber open at a front end thereof and closed at a rear end thereof by an annular portion; the inner cylinder is closed at a front end thereof, and a rear end thereof protrudes beyond said annular portion and ends with a disk; at the front end of the inner cylinder a seal is fixed, said seal being intended to slide inside said cylindrical cavity so as to create a fluid/airtight seal; on the external cylindrical element a retaining mechanism is provided engaging the plunger annular portion in order to keep the plunger inside the syringe body; means is further provided in the syringe body for carrying out an automatic plunger return towards the external part of the syringe body, when the retaining mechanism is unlocked. The automatic plunger return may be produced either as an effect of a compression in said first annular chamber, when the plunger is advanced for inserting the needle into the patient body and for incorporating therein a sample of tissue to be collected, either by a spring, arranged in the first annular chamber, said spring being compressed by the forward stroke of the plunger. This type of syringe requires a quite complex and expansive construction. Furthermore, this syringe does not assure that the tissue sample which is desired to be collected is separated from the rest of tissue, in the region where the sample is collected. Therefore, the sample may not be entrapped inside the needle and, in this case, the biopsy has to be repeated, which implies further pain and trouble for patient. The present invention intends to overcome the above-indicated drawbacks . An object of the present invention is to provide a biopsy device which is relatively simple and economical to be produced and which allows the risk of failing in collecting the biopsy sample to be minimized. According to the present invention, a biopsy device is provided, comprising a hollow body inside which a plunger is slidable, a mandrel being fixed at one end of said plunger, said plunger being slidable between a first rearward position and a second forward position with respect to said hollow body, said plunger being associated with return means suitable for producing an automatic movement of said plunger from said forward position to said rearward position, characterized in that it comprises cannula means slidably coupled with said mandrel, support means, connected to said hollow body, for supporting said cannula means, said support means comprising sliding means suitable for causing said cannula means to slide between a first operating position and a second operating position. Owing to the invention, the resection of tissue sample to be collected from the patient body may be securely carried out, for subsequently sucking said tissue sample inside the cannula means, the resection being obtained by advancing the cannula means from said first operating position to said second operating position. The automatic forward movement of cannula means and the automatic plunger retraction make the device simple and comfortable to be actuated by the operator, even with a single hand, the second hand being usable, for example, for keeping in a right position the tissues from which the biopsy sample has to be collected. In a preferred embodiment of the present invention, first retaining means are provided for retaining said return means for automatic plunger return and second retaining means for retaining said sliding means. This allows the operator to block the plunger in a forward position thereof and to block the cannula means in said first operating position, before inserting the cannula, together with the mandrel, into the patient body, so as to avoid operations compromising the cannula positioning, during or after its insertion. In a further preferred embodiment of the present invention said second retaining means is suitable for interacting with said first retaining means. This allows the operator to unlock, in a single operation, both the sliding means of cannula and the return means of plunger, advancing the cannula into the patient body for resecting a tissue sample in the region from which the biopsy sample has to be collected and causing the plunger to quickly go back so as to create inside the hollow body, and therefore inside the cannula, a vacuum assuring that the tissue sample is entrapped inside the cannula. In a still further preferred embodiment of the present invention rotation means is provided for rotating said cannula means. Said rotation means rotates the cannula which is simultaneously advanced into said second operating position, i.e., which is simultaneously advanced inside the patient body, thus making easier the resection of tissue sample to be collected. The invention will be described below, with reference to the enclosed drawing tables, in which: Figure 1 is a longitudinal section of a device for needle biopsy according to the invention, in a first operating position; Figure 2 is a section like Figure 1, with the device according to the invention in a second operating position; Figure 3 is an enlarged detail of Figure 1, showing the relative position of cannula means and mandrel, in said first operating position; Figure 4 is an enlarged detail of Figure 2, showing the relative position of cannula means and mandrel in said second operating position; Figure 5 is a detail like Figure 3, concerning a different embodiment of the device according to the invention; Figure 6 is a detail like Figure 4, concerning the embodiment of Figure 5. With reference to Figure 1, the device 1 according to the invention comprises a hollow body 2, for example substantially cylindrical, ending at one side thereof with a section 2a of reduced diameter. A plunger 3 is slidably coupled within the inner part of the hollow body 2, said plunger 3 being provided with an end portion 3a having a reduced diameter. The plunger 3 is further provided with first disengageable retaining means 4, 5, consisting of a rod 4, ending, at a free end thereof, with a tooth 5 suitable for coupling with the edge of an opening 6 made in the wall of hollow body 2, at the base of said reduced diameter section 2a. The rod 4 is substantially arranged parallel to the reduced diameter portion 3a of plunger 3. At the free end of portion 3a of plunger 3 an end of a mandrel 8 is fixed, said mandrel 8 being provided with a penetration pin 25 and passing through a first centring and guiding element 7 fixed to the free end of section 2a of the hollow body 2. Inside the hollow body 2, around said portion 3a of reduced diameter of the plunger 3, a first elastic element 9 is arranged, for example a first helicoidal spring which, when the plunger 3 is advanced inside the body 2, remains compressed between the base of said portion 3a of plunger 3 and the base of said section 2a of body 2. At the free end of said section 2a of the cylindrical body 2 a second centring and guiding element 10 is fixed, comprising a first fixed portion 11, connected to said hollow body 2, and a second movable portion 12 suitable for sliding inside said first fixed portion. To the movable portion 12 a cannula 13 is fixed, for example made of metal, inside which the mandrel 8 may slide. The first fixed portion 11 of the second centring and guiding element 10 is internally provided with a cavity 14 with which said second movable portion 12 is slidably coupled. The cylindrical cavity 14 communicates with the cannula 13 and the hollow body 2 through a hole 26, made on the bottom 18 of chamber 14, and through the first centring and guiding element 7. Said second movable portion 12 consists of a sleeve 12a, ending at an end with an enlargement 12b which may abut on the free end of the first fixed portion 11. On the external surface of the sleeve 12a a helicoidal groove 15 is made, said helicoidal groove 15 being suitable for coupling with a protrusion 16 made on the internal surface of the cavity 14. The sleeve 12a is movable between a first operating position, shown in Figure 1, wherein it is fully retracted into the cavity 14 and a second operating position, shown in Figure 2, wherein it partially protrudes from the cavity 14. When the sleeve 12a is caused to slide inside the cavity 14, coupling between the protrusion 16 and the helicoidal groove 15 produces a rotation of sleeve 12a and cannula 13 fixed thereto. Inside the cavity 14 a second elastic element 17 is arranged, for example a second helicoidal spring which, when the sleeve 12a is brought into said first operating position, is compressed between the sleeve 12a and the bottom 18 of the chamber 14. The device 1 is further provided with second disengageable retaining means 19, suitable for blocking the sleeve 12a in said first operating position. The retaining means consists of a lever 19 hinged to the device 1 at an intermediate point thereof, for example through elastic hinge means 20. The lever 19 is provided, at a first end, with a tooth suitable for being inserted into an opening 22 of the fixed portion 11 of the second centring and guiding element 10 and for engaging with an annular groove 23 of the sleeve 12, in order to prevent any sliding of the sleeve with respect to the cavity 14. The second end of the lever 19 is suitable for interacting with the tooth 5 arranged at the free end of the rod 4, so as to disengage it from the edge of opening 6 of body 2, in order to unlock the plunger 3. The mandrel 8 may be provided, near the penetration pin 25, with a seat 24 suitable for receiving a sample of tissue to be collected from the patient body. The seat 24 improves reliability in collecting a tissue sample, since it is substantially impossible that the sample may flow out of the cannula 13 while said cannula is extracted from the patient body. The device 1 according to the invention works as explained below: before introducing the needle 8 into the patient body, the operator advances the plunger 3, compressing the first spring 9, until the tooth 5 of the rod 4 couples with the edge of the opening 6 of body 2, after passing through it. In addition, the operator moves the sleeve 12a to said first operating position, for example by acting on the enlargement 12b, until the tooth 21 of the lever 19 enters the annular groove 23 blocking the sleeve in said first operating position. Thus, the second spring 17 is compressed inside the cavity 14. In this condition, the relative position of cannula 13 and mandrel 8 is shown in Figure 3, with the pin of the mandrel 8 protruding from the cannula 13. The operator may now insert the mandrel 8 and the cannula 13 into the patient body, until the region where the sample of tissue has to be collected is reached. After positioning mandrel 8 and cannula 13 in said region, the operator applies a pressure on the second end of lever 19, in the direction of arrow F (Figure 1) , rotating the lever around the elastic hinge 20 so that the tooth 21 disengages from the annular groove 23 of sleeve 12a and the second end of the lever pushes downward the tooth 5 of rod 4, disengaging it from the edge of the opening 6. Thus, the sleeve 12a and the plunger 3, being no more restrained by respective retaining means, may freely slide as an effect of action carried out on them by the second spring 17 and by the first spring 9, respectively. The sleeve 12a comes out from the cavity 14 so as to move into its second operating position, shown in Figure 2, advancing the cannula 13 into the patient body and simultaneously rotating it. During its advancing and rotating movement, the cannula 13 covers the end of mandrel 8, until said cannula 13 extends beyond the pin 25 of mandrel 8 for a section corresponding roughly to the length of the tissue sample to be collected and separates said sample from the surrounding tissue. The plunger 3 is simultaneously quickly pushed back by the action of first spring 9, creating a vacuum inside the body 2 and, therefore, inside the chamber 14 and the cannula 13 communicating with said chamber. This vacuum sucks and entraps the tissue sample inside the cannula 13, the risk that the tissue sample may escape from the cannula 13 when said cannula is extracted from the patient body being thus avoided. The operator may easily operate with one finger on the lever 19, in order to unlock the sleeve 12a and the plunger 3, while the other fingers are used for keeping the device 1 in a right position. This allows the operator to have the other hand free, for example for keeping the patient tissues in a right position, while the sample is collecting. Figures 5 and 6 show how the device 1 according to the invention works in a different embodiment in which the mandrel 8 is provided, near the pin 25, with a seat 24 for receiving the tissue sample to be collected. In this embodiment, when the cannula 13 is in its first operating position, the mandrel 8 protrudes from said cannula for a length sufficient for bringing the whole seat 24 outside the cannula 13. After the mandrel and the cannula have been inserted into the patient body, when the operator unlocks the plunger 3 and the sleeve 12a, the cannula 13 advances, rotating around its longitudinal axis, until it fully covers the seat 24. Thus, the tissue sample to be collected is separated from the surrounding tissue and entrapped in the seat 24. In the practical embodiment, the materials, the dimensions and the construction details may be different from those indicated, but technically equivalent thereto, without departing from the legal domain of the present invention.

Claims: CLAIMS 1. Biopsy device comprising a hollow body (2) inside which a plunger (3) is slidable, a mandrel (8) being fixed at one end of said plunger (3), said plunger (3) being slidable between a first rearward position and a second forward position with respect to said hollow body (2), said plunger (3) being associated with return means (9) suitable for producing an automatic movement of said plunger (3) from said forward position to said rearward position, characterized in that it comprises cannula means (13) slidably coupled with said mandrel (8), support means (10), connected to said hollow body (2), for supporting said cannula means (13), said support means (10) comprising sliding means (12) suitable for causing said cannula means (13) to slide between a first operating position and a second operating position. 2. Device according to claim 1, wherein said return means comprises elastic means (9) , acting on said plunger (3) . 3. Device according to claim 2, wherein said elastic means (9) is inserted inside said hollow body (2) . 4. Device according to any of claims 1 to 3, wherein said plunger (3) comprises an end portion (3a) having a reduced diameter. 5. Device according to claim 4, wherein said first elastic means comprises a first spring (9) ensheathing said end portion (3a) . 6. Device according to any of preceding claims, wherein said plunger (3) is associated with first disengageable retaining means (4, 5) . 7. Device according to claim 6, wherein said first retaining means (4, 5) comprises a rod (4), fixed to said plunger (3) and parallel to said end portion (3a) , said rod ending with a tooth (5) suitable for engaging with the edge of an opening (6) made in a wall of said hollow body (2) . 8. Device according to any of preceding claims, wherein said support means (10) for supporting said cannula means (13) comprises a first fixed portion (11) coupled with said sliding means (12) . 9. Device according to claim 8, wherein said support means (10) for supporting said cannula means (13) comprises a second movable portion (12) constituting said sliding means. 10. Device according to claim 9, wherein said second movable portion comprises a sleeve (12a) slidably coupled within a cavity (14) of said first fixed portion (11) . 11. Device according to claim 10, wherein said sliding means (12) comprises second elastic means (17) suitable for interacting with said sleeve (12a) . 12. Device according to claim 11, wherein said second elastic means comprises a spring (17) arranged between said sleeve (12a) and the bottom (18) of said cavity (14). 13. Device according to any of claims 10 to 12, wherein said cavity (14) communicates with said cannula means (13) and with said hollow body (2) . 14. Device according to any of claims 10 to 13, wherein said sleeve (12a) is provided, on an external surface thereof, with a helicoidal groove (15) which may be engaged by a protrusion (16) , said protrusion (16) being obtained on an inner wall of said cavity (14) . 15. Device according to any of claims 10 to 14, wherein said sleeve (12a) is provided at one end thereof with an enlargement (12b) suitable for abutting on a free end of the first fixed portion (11) of said support means (10) . 16. Device according to any of preceding claims, wherein said sliding means (12) is associated with second retaining means (19, 22) . 17. Device according to claim 16, wherein said second retaining means (19, 22) comprises lever means (19) ending at a first end with coupling means (21) suitable for being coupled with said sleeve (12a) . 18. Device according to claim 17, wherein said coupling means comprises a tooth (21) which may be inserted into an annular groove (23) of said sleeve means (12a) . 19. Device according to claim 17, or 18, wherein said lever means is connected to said hollow body (2) by hinge means (20) . 20. Device according to claim 19, wherein said hinge means is elastic hinge means (20) . 21. Device according to any of claims 17 to 20, wherein said lever means (19) is suitable for interacting with said first retaining means (4, 5) . 22. Device according to claim 21, wherein one end of said lever means (19) opposite to said tooth (21) is arranged so as to contact said tooth (5) of said first retaining means (4, 5) in order to disengage said tooth (5) from the edge of said opening (6) . 23. Device according to any of preceding claims, wherein said mandrel (8) is provided, near a penetration pin (25) thereof, with a seat (24) suitable for receiving a tissue sample to be collected.

Inventors: PALMIERI BENIAMINO, PALMIERI, BENIAMINO
Applicants: H S HOSPITAL SERVICE S P A, PALMIERI BENIAMINO, H.S. HOSPITAL SERVICE S.P.A., PALMIERI, BENIAMINO
Application year: 2001
Main classification: A61B10
IPC codes: A61B10