Method for producing a surgical handheld device, and a surgical handheld device

Abstract

A surgical handheld devices are essentially made up of a device body or main body and of a tubular shaft. In the production of known surgical devices, the tubular shafts are welded to the device bodies. A large number of very complex work steps are necessary for this purpose. On account of the high quality demands placed on surgical handheld devices in respect of mechanical stability and sterility, the weld seam has to meet the most stringent requirements. The invention makes available a method for producing a surgical handheld device, which can be used particularly easily and reliably. This is achieved by the fact that at least one device body and at least one tubular shaft of a surgical handheld device are connected to each other with form-fit engagement by hydroforming.

Claims

1. A method for producing a surgical handheld device, having at least one tubular shaft and at least one device body, wherein: connecting at least one device body and at least one tubular shaft with form-fit engagement by hydroforming; guiding at least one portion, of the at least one tubular shaft into a receiving space of the at least one device body; fixing the at least one device body to the at least one tubular shaft together; sealing open ends of the at least one device body and/or of the at least one tubular shaft; building up a hydraulic pressure in the at least one shaft; pressing the at least one portion of the at least one tubular shaft, which is located inside the receiving space of the at least one device body, by pressure applied to an inner contour of the at least one device body, as a result of which the form-fit connection between the at least one tubular shaft and the at least one device body is generated.

2. The method as claimed in claim 1 for producing a surgical handheld device, wherein the at least one device body is a main body or an attachment body or a cone of the device body or a further component of the handheld device.

3. The method as claimed in claim 1 for producing a surgical handheld device, wherein the at least one tubular shaft is a shaft, a tube or an outer tube or an inner tube.

4. The method as claimed in claim 1 for producing a surgical handheld device, wherein an inner contour of the at least one device body has at least one undercut and/or at least one projection against which the at least one tubular shaft is pressed with form-fit engagement.

5. The method as claimed in claim 1 for producing a surgical handheld device, wherein the at least one tubular shaft is subjected to a predefined pressure, or the pressure is increased until a sufficiently firm form-fit connection is produced.

6. The method as claimed in claim 1 for producing a surgical handheld device, wherein the at least one device body is an optical plate.

Description

(1) A preferred illustrative embodiment of the invention is described in more detail below with reference to the drawing, in which:

(2) FIG. 1 shows a schematic view of a resectoscope,

(3) FIG. 2 shows a schematic partial view of a main body and of a shaft, and

(4) FIG. 3 shows a schematic partial view of a main body and of a shaft.

(5) FIG. 1 shows a resectoscope 10 as an example of a surgical handheld device. This resectoscope 10 is essentially made up of a transporter 11, a grip unit 12 and a shaft 13. It is expressly noted that the surgical handheld device can also be a device other than the resectoscope 10 shown here. The resectoscope 10 shown in FIG. 1 serves only to illustrate the invention. As has already been stated, the measures and features according to the invention can also be transposed to other surgical devices and can also be implemented simultaneously or successively on a plurality of components or bodies and shafts.

(6) In the illustrative embodiment of a surgical handheld device shown here, the shaft 13 is composed of an outer shaft tube 14, an optical unit 15 and an electrode instrument 16. The optical unit 15 is composed of a long tube in which lenses or glass fibers can be arranged, such that a region at the distal end of the shaft 13 can be observed through an eyepiece 17 arranged proximally on the shaft 13. For a more detailed description of the resectoscope 10 shown here, reference is made to the known prior art.

(7) As is customary, the surgical handheld device or resectoscope 10 shown in FIG. 1 also has a device body 18. This device body 18, also referred to as main body or attachment body, is an essential part of the device. For example, the grip unit 12 can be arranged on each main body 18, or further components for manipulation or control of the instrument. In the case of the resectoscope 10 shown here, the optical unit 15 inter alia is guided through the device body 18.

(8) The tubular shaft 13 is firmly connected to the device body 18. Depending on the nature of the surgical handheld device, different instruments are guided in the shaft 13, as a result of which they are protected against external influences. According to the present invention, a proximal end region 19 of the shaft 13 is connected with form-fit engagement in a receiving space 20 of the housing body 18. To do this, the end region 19 of the shaft 13 is first of all guided into the receiving space 20 of the body 18 (FIG. 2). When the shaft 13 is subjected to a hydraulic pressure, the distal end region of the shaft 13 adapts to an inner contour 21 of the device body 18 (FIG. 3). The inner contour 21 of the device body 18 can have a ring-like undercut 22 in which the shaft 13 fits. By this expansion of the proximal end region 19 of the shaft 13, the form-fit connection is produced. This is shown highly schematically in FIG. 3.

(9) In the method described here for producing the surgical handheld device, an external diameter of the shaft 13 is only negligibly smaller than the internal dimensions of the receiving space 20 of the device body 18. If the difference between these dimensions were too great, the reshaping of the shaft 13 or the adaptation of the circumference of the shaft 13 to the inner contour 21 would lead to an unsatisfactory result. On the one hand, a form-fit connection could not be produced, or at best only an inadequate form-fit connection could be produced, and, on the other hand, the shape of the shaft 13, or of the end region 19 of the shaft 13, would probably change in such a way as to cause a material weakness. If the difference between said dimensions is only slight, the outer circumference of the shaft 13 adapts optimally to the inner contour 21 of the device body 18, specifically without the shape or the material nature of the shaft 13 being adversely affected by the reshaping process. Moreover, by virtue of this relatively slight reshaping, less force needs to be applied.

(10) To ensure that the force acting on the wall of the shaft 13 reshapes only the end region 19 of the shaft 13, and not the entire shaft and the main body, provision is made according to the invention that, prior to the application of pressure, both the device body 18 and the shaft 13, which is already positioned in the receiving space 20, are enclosed by a mold (not shown here). This mold can ideally consist of two halves. However, it is also conceivable that the mold, in particular for complex shapes of the device body 18, can be composed of a plurality of elements. The mold, in particular the assembled mold, is designed in such a way that it withstands the pressure acting on the shaft 13 and thus prevents a reshaping of the shaft 13 and of the body 18.

(11) However, it is also conceivable that the mold or the mold elements have undercuts or the like, such that the components, in particular the shaft 13, of the handheld device undergo additional reshaping when pressure is applied. By means of this additional reshaping, the components can be prepared for special uses or requirements.

(12) The hydraulic or pneumatic pressure is applied by a corresponding generator (not shown). This generator is connected to the shaft 13 and/or to the device body 18 via a line and a connector. For regulated or controlled generation of pressure, at least one valve can be arranged between the line and the stated components. The coupling of the line or of the valve to the shaft 13 or to the device body 18 can be effected via a special connector or flange or the like. After completion of the reshaping process, the pressure is reduced and the connection is uncoupled. Thereafter, the components simply have to be cleaned with the fluid that may be used. The reshaping of the shaft portion or the form-fit connection between the shaft 13 and the device body 18 is thus reduced to a small number of steps that are easy to perform.

(13) With the insertion of the shaft end 19 into the receiving space 20, the fixing of the components in the mold and the application of pressure, the method is particularly simple and reproducible. At least some of these steps can be performed fully automatically, such that this method according to the invention also reduces costs.

(14) In this method, the cross section of the shaft 13 is not limited to a circle or ring. Instead, the cross section of the shaft 13 and the cross section of the receiving space 20 can also have another shape, for example an ellipse or possibly an oval or the like. Polygonal cross-sectional shapes are also conceivable. Through a combination of several in particular differently shaped undercuts 22 and preferably projections on the inner contour 21 of the device body 18, it is possible to produce a particularly reliable and stable form-fit connection.

(15) Besides the embodiments shown in FIGS. 2 and 3, in particular as regards the shape of the receiving space 20, of the inner contour and of the undercuts 22, shapes other than those shown here are also provided.