OPERATING DEVICE FOR A STYLET UNIT

Abstract: The invention relates to a device for manipulating a stylet unit (12), comprising a stylet sleeve (16) and a stylet (14), for positioning an electrode cable in a body cavity. The device (10) has a first part and a second part (18, 20), that are able to move in relation to each other. A groove (26) is arranged in the interface area (22) of one part (20), which presses against a flat surface (24) on the other part (18).

Description: Operating device for a stylet unit Field of the invention The present invention relates to a device for manipulating a stylet unit, consisting of a stylet sleeve and a stylet located therein, for positioning an electrode cable in a body cavity, according to the preamble of the attached main claim. The prior art A device for operating a stylet unit of the above kind for achieving a desired stiffening of an electrode cable during its advancement into a body cavity, e.g. via a vein into the atrium of the heart, and a desired final position for the distal end of the electrode cable by providing the cable with a bent - or J-like shape is previously known through US-A-5 170 787. Here, the distal end of the stylet is pre-bent and is kept retracted inside the stylet sleeve during the electrode cable's insertion phase, giving the distal end of the electrode cable an essentially straight shape, the stylet, in the final positioning of the distal end of the electrode cable, being exposed outside its tubular sleeve to cause the distal end of the electrode cable to assume the desired curved shape. In order to achieve the exposure of the pre-bent distal end of the stylet outside its tubular sleeve, the aforementioned US-A-5 170 787 proposes a device which either moves the stylet distally in relation to a stationary sleeve or moves the tubular sleeve proximally in relation to a stationary stylet. In principle, the latter option is preferable, since it does not entail any movement of the electrode cable in relation to the stylet unit's operating device. The known operating device comprises two stiff tubes, one telescoping inside the other, in order to obtain a stiffening that prevents the stylet frcm buckling when its free proximal end is slid distally inside the tubular sleeve respectively when the tubular sleeve is slid proximally over the free proximal end of the stylet in the operating device. This means that the operating device's total linear elongation is relatively large, since the total length of the telescoping tubes must be twice the length of the stylet's stroke in relation to the tubular sleeve. Our previous patent application EP-A-773036 proposed an operating device for a stylet unit of the initially cited kind in which the stiff, telescoping tubes of the operating device according to the American patent are replaced by a conpressible helical spring which supports the free, proximal end of the stylet -and which, in turn, is guided with a tight fit in an elongate cavity in a handle housing. In this way the total length of the operating device can be shortened considerably while the number of device parts could be reduced, resulting in lower manufacturing costs for the operating device. Suirπiary of the invention However, the purpose of the present invention is to propose an operating device of the initially mentioned kind which can be even shorter, have even fewer parts and, accordingly, be made cheaper than previously proposed devices while retaining the requisite strength and reliability. For this purpose, the means for stylet support and control in the operating device according to the present invention is characterized by the features set forth in the characterizing part of the appended main claim. In this instance, the stiff, telescoping control tubes or the stylet guiding spring in previously proposed operating devices are not needed and are replaced by a simple stylet groove at the interface between both main parts of the operating device. The shortest total length for the operating device is achieved when one of its parts is devised as a rotatingly supported roller body in a handle section in which the stylet and stylet sleeve are able to traverse a non- linear path when the stylet and stylet sleeve are moved in relation to one another when the configuration of the distal end of the electrode cable is to be changed. Additional features of the operating device according to the invention -are set forth in the subsequent dependent claims and will be further described with reference to attached drawings. Description of drawings FIG. 1 is a schematic, skeleton drawing in perspective of an operating device with linear operation according to a first embodiment of the present invention,* FIG. 2 is an end view of the operating device in FIG. 1; FIG. 3 is a fragmentary, longitudinal sectional view of the operating device in the area of the stylet's attachment to the handle section; FIG. 4 is a schematic, exploded skeleton view in perspective of a second embodiment of an operating device, with non-linear operation, according to the invention; FIG. 5 is a schematic side view of a first, practical embodiment of the operating device, with non-linear operation, according to the invention; FIG. 6 is a schematic side view of a second, practical embodiment of operating device, with non-linear operation, according to the invention. Preferred embc-diments FIG. 1 shows a schematic view of an embodiment, generally designated 10, of a device according to the invention for manipulating a stylet unit 12 during the introduction and implantation of an electrode cable (not shown) in a bcidy cavity, such as through a vein into the right atrium of the heart, for the purpose of achieving the desired stiffening of the electrode cable during its introduction and achieving the desired positioning and configuration, e.g. a J shape, for the distal end of the electrode cable. The operating device 10 according to the invention is therefore intended for manipulating a stylet unit 12 of the kind corrprising an internal stylet 14 enclosed in a tubular sleeve 16, both the sleeve 16 and the stylet 14 being intended for insertion into the central channel of the electrode cable for stiffening the cable during its introduction and for bending the distal end thereof into the desired shape. For this purpose, the distal end section of the internal stylet 12 is pre-bent in the known manner but enclosed inside the tubular sleeve 16 during the electrode cable's advancement in order to keep the distal end of the stylet unit 12 and, accordingly, the electrode cable essentially straight. When the distal end of the electrode cable has been maneuvered into e.g. the right atrium of the heart, the tubular stylet sleeve 16 can be retracted, whereupon the pre-tensiσning of the exposed, pre-bent distal end section of the stylet 14 inside the electrode cable causes the distal end section of the electrode cable to bend into the desired shape, e.g. an L shape or a J shape. Alternately, the stylet can be moved out from the stylet sleeve, but this would result in simultaneous retraction of the electrode cable from the operating device. The operating device 10 according to the invention is therefore designed to guide this movement of the stylet sleeve 16 in relation to the stylet 14. The embodiment of the operating device 10, shown in FIGS. 1-3, according to the invention is of a type with linear operation and comprises, in principle, a first part, for instance a housing 18 devised as a handle, and a second part, devised as a slide, which is supported so as to be linearly movable into and out from the housing 18. The slide 20 has an upper surface 22 which slides with a tight fit against the opposing surface 24 of a cavity in the housing 18. A groove 26, in which a proximal end section 28 of the stylet sleeve 16 is attached, is made on the upper surface 22 of the slide 20. A proximal end section 30 of the stylet 14, which projects from this end section 28, extends to the rear in the groove 26 to an attachment point at which the end of the stylet 32 is bent up -and fastened in a perpendicular blind hole 34 opening onto the groove 26 in the housing 8, as best shown in FIG. 3. The groove 26 and the opposite surface 24 accordingly form a guide channel which encloses the stylet 14 with a relatively tight fit, preventing it from buckling when the slide 20 and stylet sleeve 16 slidingly are withdrawn to the rear. The slide 20 has a grip section 36, which extends through a slot 38 into the lower part of the housing 18 to facilitate linear movement of the slide 20 in relation to the housing 18. The operating device according to the embodiment in FIG. 1-3 operates as follows : Before the electrode cable is introduced into the body cavity, the stylet unit 12 is fully inserted into the electrode cable with the stylet 14 enclosed by the stylet sleeve 16, i.e. the operating slide 20 is held in a forward, distal end position in the housing 18. When the tubular sleeve's 16 distal end reaches the distal end of the electrode cable, the latter can be inserted into the body cavity, e.g. the right atrium of the heart. When the cable reaches the atrium, the distal end section of the electrode cable is bent into the desired L shape or J shape by retracting the slide 20, i.e. in a proximal direction, with the fingers, the tubular sleeve 14 accx*τpanying the slide 20 and exposing the pre-bent distal end of the stylet 14 at the distal end of the electrode cable, thus bending the cable into the desired shape depending on how much of the bent, distal end of the stylet is exposed. Here, the primary task of the groove 26 is to enclose or stiffen the proximal, free end section 30 of the stylet 14 with a relatively tight fit, thereby preventing buckling thereof due to friction between the stylet 14 and the sleeve 16 when the latter is retracted along the stylet 14. After the distal end of the electrode cable reaches its final position, it can be actively affixed to the heart wall by manual rotation of a rotation sleeve (not shown) , on the proximal end of the slide 20, to which the electrode cable's proximal contact pin is attached. Within the scope of the present invention, the relative movement of the housing 8 and slide 20 can alternately be reversed in the eπtoodiment according to FIGS. 1-3, i.e. the proximal end of the stylet 14 can be attached to the slide 20, the stylet housing 16 attached to the housing 18 and the groove 26 devised in the housing, the stylet 14 being insertable into and out of a stationary sleeve 16. However, this means that the distance between the distal end of the electrode cable and the operating device 10 would increase when there is distal displacement of the stylet 14, and the proximal end of the electrode cable therefore must be free to follow this movement. FIG. 4 shows a skeleton view of an alternative embodiment of the operating device according to the invention, which operates with non-linear relative movement between the stylet and the stylet sleeve. Thus, this eπibodimsnt employs a housing 18' in which a roller body 20' is rotatably arranged in a cavity 40 in the housing. The roller body 20' has a peripheral guide groove 26' for the stylet 14, and the housing 18' has a through hole 42 for the proximal end section of the stylet sleeve 16 which is to be fastened to the guide groove 26 ' , The housing 18 ' further has an attachment point 34 ' , located opposite the stylet groove 26 ' , for the proximal end of the stylet 32. Thus, by rotating the roller body 29' relative to the housing 18' , the stylet sleeve 16 can be moved towards the attachment point 34' , thereby sliding over the stylet 14, guided so as to prevent stylet buckling in the stylet groove 26' , the pre-bent distal end section of the stylet 14 being moved out from the stylet sleeve 16 to the degree required to shape the distal end section of the electrode cable into a suitable J shape. Since non-linear relative motion is achieved between the stylet 14 and the sleeve 16, in this instance, the operating device 16 can be devised with a shorter length. FIGS. 5 and 6 schematically depict two practical erribodiments of a control device according to FIG. 4. In FIG. 5, the housing 18' has been devised as a handle, so rotation of the roller body 20' can be performed with one finger. In the embodiment according to FIG. 6, the roller body 20" can be rotated in relation to the handle 18" with a lever 44 in the middle of same, so the stylet unit can be manipulated by manually pressing the lever 44 -and handle 18" towards each other. Here, the lever 44 is preferably pre-tensioned with a spring (not shown) which presses the lever 44 tow-ards an end position away from the housing 18" . In the eπtxx±Lments according to FIGS. 4-6, the relative movement of the stylet and the stylet sleeve also can be reversed, i.e. the stylet's and sleeve's attachment points -and the groove's location in the housing and roller body respectively can change place.

Claims: Claims 1. A device for manipulating a stylet unit (12) , comprising a stylet sleeve (16) and a stylet (14) located therein, for positioning an electrode cable in a body cavity, said device (10) comprising a first part and a second part (18, 20; 18', 20',* 18'', 20"), which are joined together and movingly arranged in relation to each other, one of the said first part and second part being adapted to receive and fixate a proximal end (32, 28) of one of said stylet (14) and stylet sleeve (16) , whereas the other of the said first part and second part is adapted to receive and fixate a proximal end {28, 32) of the other stylet (14) and stylet sleeve (16) , and a means in the device adapted for supporting and guiding a proximal section (30) of the stylet (14) which projects outside the stylet sleeve (16) when stylet and stylet sleeve move in relation to each other, characterized in that the means adapted for supporting -and guiding the stylet (14) consists of a groove, located in one of the mutually moveable parts (8, 20; 18', 20'; 18' ' , 20' ' ) , which is to enclose the stylet (14) -and which is devised in the surface of one part in the interface area (22) touching the other part. 2. The device according to claim 1, characterized in that the first part (18; 18'; 18") is adapted to receive and fixate the proximal end (32) of the stylet (14), whereas the second part (20; 20'; 20") is adapted to receive the proximal end of (28) of the stylet sleeve (16) , said first part (18, 18', 18") being movably supported relative to said second part (20; 20' ; 20") . 3. The device according to claim 2, characterized in that the groove (26; 26') which is to surround the stylet (14) has a depth and width largely corresponding to the diameter of the stylet sleeve (16) . 4. The device according to claim 1, characterized in that said first part (18; 18',* 18") is stationary in relation to said second part (20; 20'; 20") which is movingly supported, said second part being adapted to receive and fixate the proximal end of the stylet (14) , whereas said first part is adapted to receive the proximal end of the stylet sleeve (16) . 5. The device according to claim 4, characterized in that the groove to enclose the stylet has a depth and width which corresponds at least to the diameter of the stylet (14) but does not essentially exceed the diameter of the stylet sleeve (16) . 6. The device according to any of claims 1-5, characterized in that said first part (18) is devised as a handle section, and said second part is devised as a slide (20) capable of linear rrtovement in relation to the handle part. 7. The device according to any of claims 1-5, characterized in that said second part (20) is devised as a handle section, and said first part is devised as a slide (18) capable of linear movement in relation to the handle part. 8. The device according to any of claims 1-5, characterized in that said first part (18'; 18") is devised as a handle section and said second part as a body (20' ; 20") which is supported so as to be able to rotate in relation to the handle section. 9. The device according to claim 8, characterized in that the rotatable body (20'; 20") is in the form of a roller body. 10. The device according to claim 9, characterized in that a lever (44) , devised to interact with the handle section (18"), is connected to the roller body (20") . 11. The device according to any of claims 1-5, characterized in that said second part (20' ; 20" ) is devised as a handle section and said first part as a body (18' ; 18" ) which is supported so as to be able to rotate in relation to the handle section. 12. The device according to claim 11, characterized in that the rotatable body (18' ; 18" ) is in the form of a roller body. 13. The device according to claim 12, characterized in that a lever (44) , devised to interact with the handle section (20") , is connected to the roller body (18' ') . 14. The device according to any of claims 1-13, characterized in that the proximal end (32) of the stylet (14) is to be fastened to one of the first and second parts by means of a bend of the end of the stylet which is approx. 90°.

Inventors: BOSTROEM MATS, BOSTROEM, MATS
Applicants: BOSTROEM MATS, PACESETTER AB, BOSTROEM, MATS
Application year: 1997
Main classification: A61M25
IPC codes: A61M25, A61N1