Medical instrument

Abstract

Medical instrument or device with a housing (15) and with at least one electrical or electronic switch (1, 2) arranged therein, which can be mechanically actuated from outside the housing (15), wherein the switch (1, 2) has a diaphragm (16) for actuation, which is part of a metallic wall section that is hermetically integrated into the housing wall, characterized in that the metallic wall section integrated into the housing wall has a ring section (19) surrounding the diaphragm (16) which is supported on the housing wall, wherein the switch (1, 2) is designed as a unit (26) with a switch housing (27) which is closed off on one side by the diaphragm (16) and which forms the metallic wall section integrated into the housing wall.

Description

[0001] The invention relates to a medical instrument or device comprising a housing and at least one electrical or electronic switch arranged therein, which can be mechanically actuated from outside the housing.

[0002] Medical devices, and especially medical instruments such as endoscopes, must be regularly cleaned and disinfected in accordance with hygiene requirements. Surface disinfection, such as spraying on a chemical substance, is often insufficient. Endoscopic instruments, for example, which are used during internal surgery, must be cleaned and autoclaved after use. This requires not only a hermetic seal of the instruments and their interiors, but also a suitable choice of materials, as plastics in particular age and become brittle relatively quickly during such processes.

[0003] This poses a particular problem when the instruments or devices contain electrical or electronic components whose control is manually triggered externally, typically by a switch. Such switches are found in a wide variety of medical technology products, for example, in camera heads, video endoscopes, motorized handgrips, and the like.

[0004] To trigger electrical switching operations in endoscopes and endoscopic systems, either non-permanently hermetically sealed switch assemblies combined with glass feedthroughs for transmitting the electrical signal through the housing wall, or components with integrated permanent magnets that are movably mounted outside a hermetically sealed housing, are currently used. This creates a magnetic field whose field lines also pass through the hermetically sealed housing containing the electronics or sensors. When the switch is actuated and the permanent magnet moves, the intensity and / or direction of the field changes. This is detected inside the housing, for example by Hall effect sensors, and used to trigger a switching operation.The construction of such a switch is comparatively complex and expensive; moreover, the calibration of the switch is often difficult, as the magnetic field and the course of the field lines depend on the permeability of all surrounding components, the materials used, tolerances and manufacturing parameters.

[0005] German patent DE 10 2009 004 975 A1 describes a control element in the form of a snap disc. US patent 2009 / 0078553 A1 describes a switch for an electrical device, wherein the switch has an elastic trigger having an electrically conductive inner surface and an outer contact surface. German patent 10 2009 022 687 B3 describes a push button for a medical handling device. German patent 10 2015 004 546 A1 describes a medical device designed as an endoscope.

[0006] In light of this prior art, the invention is based on the objective of designing a medical instrument or device, which has a housing and at least one electrical or electronic switch arranged therein, which can be mechanically actuated from outside the housing, in such a way that the construction can be made simpler and more cost-effective.

[0007] According to the invention, this problem is solved by a medical instrument or device having the features specified in claim 1. Advantageous embodiments of the invention are described in the dependent claims, the following description, and the drawing.

[0008] The medical instrument or device according to the invention, which has a housing and at least one electrical or electronic switch arranged therein, which can be mechanically actuated from outside the housing, is designed according to the invention such that the switch has a membrane for actuation which forms part of the housing wall of the medical instrument or device or which is part of a wall section which is hermetically and preferably materially bonded to the housing wall of the medical instrument or device.

[0009] The housing and diaphragm can be made of plastic, for example, but it is particularly advantageous if they are made of metal. Therefore, the medical instrument advantageously has a metal housing, in which case the diaphragm is designed as a metallic membrane and is bonded to the housing wall of the medical instrument or device by welding or soldering. The diaphragm can also be part of a metallic wall section that is bonded to the housing by welding or soldering.

[0010] The basic idea of ​​the solution according to the invention is to form a portion of the housing wall as a membrane, thus enabling mechanical actuation of the switch from the outside without interrupting the housing surface or requiring a sealing joint. The membrane is designed to withstand the expected number of switching cycles. In principle, the membrane can be formed by thinning the housing wall accordingly. However, from a manufacturing and functional perspective, it is generally more advantageous to provide the membrane within a metallic wall section that is hermetically and materially bonded to the metallic housing wall by welding or brazing. This design has the advantage that only a recess for the metallic wall section containing the membrane needs to be provided on the housing side, and only one welded or brazed connection is required.The actual component, namely the membrane with the surrounding wall section, can be manufactured separately and thus optimized not only in terms of production technology but also in terms of function by using a material particularly suitable for this function. It goes without saying that such a design is also possible using plastics.

[0011] The design according to the invention can be used for both electrical switches, in which an electrical contact is closed by pressing the diaphragm, and electronic switches. This includes switches that operate by momentarily closing an electrical contact, as is the case with a push button, according to the principle of a self-holding relay, for example, by connecting the pull-down input of an electrical switch, e.g., a transistor, to the ground potential of the housing. Alternatively, the switch can operate without contact, for example, if a permanent magnet is arranged on the inside of the diaphragm, triggering a reed switch behind it. A capacitive switch that reacts to the approach of the diaphragm can also be provided.

[0012] The membrane, as defined in the present invention, is not necessarily a thin, elastic, and movable wall extending over its entire surface, but can also be elastically deformable only in sections and otherwise quasi-rigid, so that it deforms only in sections when manually actuated. The membrane can be designed such that a section with a corrugated cross-section, functionally corresponding to a bellows, is arranged around an inner quasi-rigid pressure surface section.

[0013] According to the invention, it is particularly advantageous for the moving part of the diaphragm, which is subject to deflection, to be made of spring steel, firstly to enable automatic return to its original position, and secondly to ensure the required load cycles. Advantageously, the metallic wall section containing the diaphragm is made of such corrosion-resistant spring steel, which is then connected to the instrument or device housing, typically also made of stainless steel, by welding or brazing.

[0014] According to an advantageous embodiment of the invention, the diaphragm is designed such that it has an inherently stable position when the switch is not actuated, i.e., when it is ready for actuation. In the position in which the switch is actuated, that is, when the diaphragm is pressed towards the interior of the housing by an external force, it advantageously has a metastable position. This ensures that, upon application of a corresponding external force, the diaphragm is always brought into this metastable position, in which the switching function is triggered. However, it is designed such that it automatically returns to its stable position when not actuated. Thus, to trigger the switching function, only a pressure force needs to be applied to the diaphragm until it is moved from its stable position into the metastable position, after which the diaphragm automatically returns to its stable position.

[0015] Not only for achieving the final function, but also for the membrane to be convexly curved outwards, at least in sections, it is particularly advantageous. A further significant advantage of this design is that the switch, and especially the membrane that is actuated by finger force, is tactile, meaning it can be located by the user without visual contact. Such an arrangement is particularly advantageous for switches on medical instruments, such as those on endoscope handles, which are manually guided and operated but are not within the user's direct line of sight during handling.

[0016] It is advantageous if at least one section of the membrane protrudes from the rest of the housing wall, so that it can be felt when running the fingers over the housing wall. If the membrane is equipped with a button, i.e., a pressure-sensitive area, which is advantageous, then it is expedient to design this button so that it protrudes from the housing wall, thus forming a raised plateau.

[0017] According to an advantageous embodiment of the invention, the diaphragm is designed as a snap disc, or a snap disc is arranged beneath the diaphragm within the housing. Such a snap disc is made of spring steel, which is typically embossed to have a stable and a metastable state. When a force is applied, it is switched from the stable to the metastable state, producing a clearly audible snapping sound due to the sudden changeover. This snapping sound is audible again when the disc springs back after the force is released. This snapping sound is particularly advantageous in applications because it signals to the user whether the switch has been actuated or, after release, whether it has been actuated, thus providing a very direct and technically simple feedback effect.

[0018] To ensure that the portion of the diaphragm responsible for triggering the switching process is not moved by the surrounding fixed wall section, which is connected to the rest of the housing by welding or brazing, since this area is brittle and therefore particularly prone to cracking, the invention provides that the diaphragm is surrounded by an annular section that is enclosed by and supported by the housing wall of the instrument or device housing, so that this annular section can only move minimally, if at all. This ensures that this integrated wall section is immobilized in the area of ​​the weld or brazed joint and is therefore not stressed by the movement of the diaphragm.It is particularly advantageous if this ring section is firmly connected to the supporting part of the housing wall by gluing, since then this ring section is not only supported but also fixed in the opposite direction by the adhesive connection and thus secured against movement.

[0019] Advantageously, according to a further development of the invention, two switches with bistable diaphragms can be arranged side by side and coupled to each other within the housing. The diaphragms can be arranged side by side on the same housing wall or on opposite housing walls, so that, for example, one diaphragm is located on the left handle side and the other on the right handle side of an endoscope. The diaphragms are bistable, meaning they are stable in both the actuated and the unactuated states. Through the coupling, they switch each other; that is, when one diaphragm is depressed, the other diaphragm is pushed out, and vice versa.This can be achieved, for example, by a rocker switch inside the housing if the switches are arranged side by side on one side of the housing, or by a coupling element, such as a rod, if the switches are arranged side by side on opposite sides. Alternatively, the diaphragms can be coupled hydraulically or pneumatically via a suitable channel connection inside the housing.

[0020] From a manufacturing perspective, it is particularly advantageous that the switch, according to the invention, is designed as a modular unit comprising the diaphragm and a switch housing that accommodates the diaphragm and forms the metallic wall section integrated into the housing wall. This unit expediently also includes at least the actual electrical switch, i.e., the contacts that are closed by pressing on the diaphragm and opened again by springing back. Depending on the specific design, the housing can also encompass the entire switch. Ideally, the switch housing with the diaphragm should be made entirely of metal and be hermetically sealed, although this is not strictly necessary, at least not towards the interior of the housing.

[0021] Such a component can be pre-assembled in a factory so that it can be integrated into various medical instruments and devices as needed, whereby only the electrical connections with the component need to be made within the housing and otherwise the component is to be integrated into a corresponding recess in the housing wall by welding or soldering.

[0022] The invention is explained below with reference to exemplary embodiments shown in the drawing. The drawing shows: Fig. 1 in a highly simplified perspective view the handle of an endoscopic instrument with two switches according to the invention, Fig. 2 a top view of a membrane, Fig. 3 - 5 Cross-sectional views of the wavy section of the membrane according to section line II-II in Fig. 2 in different embodiments, Fig. 6 in schematic cross-sectional view a switch in the unactuated state, Fig. 7. Turn the switch according to Fig. 6 in the activated state, Fig. 8 in perspective view a view of the membrane of a switch with surrounding metallic wall section as a component unit, Fig. 9 a side view of the assembly unit according to Fig. 8, Fig. 10 a section through the building unit according to Fig. 8 in a first embodiment with integrated electrical contact, Fig. 11 a section of a second embodiment according to the illustration according to Fig. 10 without further integrated components, Fig. 12 a section of the housing wall with a hermetically sealed switch of an alternative embodiment, Fig. 13 a section through a switch assembly showing the support of the switching membrane in the edge area for deburring the weld seam, Fig. 14 the detail XIV in Fig. 13 in enlarged view, Fig. 15 an exploded view of an embodiment of a switch, Fig. 16 another embodiment of a component shown accordingly Fig. 13 with bore for the injection of adhesive after welding the membrane, Fig. 17 the detail XVII in Fig. 16 in enlarged view, Fig. 18 an exploded view accordingly Fig. 15, Fig. 19 an alternative embodiment of a switch in perspective view of a wall section from the outside, Fig. 20 a view of the switch according to Fig. 19 from the inside of the case, Fig. 21 a longitudinal section through the switch according to Fig. 19 and Fig. 22 another version of the switch in longitudinal section view.

[0023] The in Fig. The handle 10 of an endoscopic instrument, not shown in detail here, has, in a manner known per se, a shaft 12 extending distally from the handle 10. This shaft may, for example, contain a working channel and / or a suction / irrigation channel, and a supply line 14 extending proximally through which the electrical and optical connections are routed from the handle 10. The construction of the endoscopic instrument is not described in detail here, as the present invention focuses solely on the design of electrical switches 1 and 2 arranged in the handle, side by side on one side of the housing 15 that encloses the handle. The housing 15 is made of stainless steel and hermetically sealed, making it autoclavable.

[0024] The electrical switches 1 and 2 on the left outside of the handle 10 are each designed in the manner of a push button; their outer surface merges into the wall of the housing 15, so that the outer surfaces of switches 1 and 2 form part of the outside of the housing 15.

[0025] Such a switch 1 is bounded externally by a diaphragm 16, which is made of non-corrosive spring steel and has a central pressure surface section 17, which transitions via a section 18 with a wave-shaped cross-section into an annular wall section 19, which is flush with the housing 15 and is firmly and tightly connected to the housing wall by welding.

[0026] In the based on the Fig. In the embodiments of the membrane 16 shown in Figures 3-5, it has a constant thickness across its entire area. This is particularly advantageous from a manufacturing perspective. However, the pressure surface section 17 and the surrounding wall section 19 can have a greater thickness than the corrugated section 18. In one embodiment, the pressure surface section 17 can move towards the interior of the housing 15, but only as a whole; the movement itself is caused by the corrugated section 18, which, like a bellows, deforms elastically when the surface 17 is compressed and springs back upon release due to the spring force of the section 18.

[0027] As illustrated by the exemplary variations of the wave-shaped section 18, 18' and 18'', the wave can essentially lie in the plane of the membrane 16, as shown in Fig. 3 shown, or perpendicular to it, as in Fig. 4 shown. When executed according to Fig. In step 5, the wave also lies in the plane of the membrane, however, the wave is not as in step 5. Fig. 3 sinusoidal but formed by inclined surfaces. The illustrated embodiments show only examples of possible wave-shaped sections 18, whose purpose is to provide the necessary material compensation when the pressure surface section 17 moves, in such a way that only elastic deformations occur, which, due to the spring force of the material, cause a return to the original shape as soon as the pressure force on the pressure surface section 17 is interrupted.

[0028] In the Fig. 6 and Fig. Figure 7 illustrates how such a diaphragm-controlled switch can be constructed. The diaphragm 20 shown there is convexly curved outwards and has a central depression 21, which forms a switching contact 22 on the inside. The diaphragm 20, made of spring steel, is hermetically integrated by welding into a wall section 23, which forms part of the housing 15.

[0029] In the Fig. The pre-tensioned concave position of the diaphragm 20 ensures its stability. Pressure on the diaphragm 20 in the area of ​​the depression 21 moves it towards the inside of the housing until it reaches the position indicated in Fig. The position shown in Figure 7 is reached, in which the switching contact 22, formed internally by the diaphragm 20, rests against a contact 25 located behind it within a holder 24 and electrically connects it to the switching contact 22. Since the diaphragm 20, which is made of metal, is then connected to the housing 15, which is also made of metal, actuation of the switch accordingly results in Fig. 7. Contact 25 is connected to ground (GND), which can be used, for example, to trigger an electronic switching operation via a suitable switching transistor. The holder 24 is made of electrically insulating material. The associated circuit arrangement can, in principle, be provided at any point within the housing 15, but is preferably arranged in the area of ​​the switch or a switch housing provided there.

[0030] Based on the Fig. 6 and Fig. In the embodiment shown in Figure 7, the membrane 20 itself forms the switching contact. It is understood that the switching contact can also be arranged directly opposite the contact 25 and is closed solely by pressure exerted by the membrane 20. In this case, an electrically insulating layer, for example a plastic film, is typically arranged between the membrane and the contact.

[0031] In principle, this can be illustrated by the following examples: Fig. 6 and Fig. The structure described in section 7 is provided within the instrument or device housing. However, it will generally be more cost-effective to design such a diaphragm-controlled switch as a modular unit, which is then hermetically integrated as a whole into a corresponding recess in the housing wall, preferably by welding. Such units / modules 26 are illustrated by the following examples: Fig. 8-12 are shown. Fig. 8, Fig. 9 to Fig. Figure 10 shows such a building unit 26, in which a membrane 16, as shown by Fig. As described in section 2, the assembly is arranged on one side, which forms the future outer surface of the housing, and has a closed housing 27 on the rear side, through which only the electrical connections, i.e., at least one electrical connection, are brought out in an electrically insulated manner. Such a component 26 is inserted into a correspondingly provided recess within, for example, the housing 15 at the handle 10 and is firmly and hermetically connected to the housing wall by a circumferential weld, so that the Fig. 1. The switch arrangement is evident.

[0032] As shown in the section view according to Fig. As can be seen in Figure 10, the assembly 26 has two switching contacts 28, which are integrated into an insulating holder 29 and are closed by an electrically conductive film arranged on the inside of the diaphragm in the area of ​​the pressure surface section 17 when the diaphragm is pressed. This electrically conductive film 30 is electrically insulated from the diaphragm 17, 18, 19 and the housing 27 by means of an insulating film 31, so that the switch can operate at any potential. The switching contacts 28 are brought out from the rear of the housing 27 in an electrically insulated manner and are connected there inside the housing 15, which forms the handle 10, in a manner known per se.

[0033] Based on Fig. Figure 11 shows that the holder 29 is in the form of a circuit board with the contacts 28, as shown in Fig. As shown in Figure 10, the mechanical movement of the diaphragm can also be removed and transferred in any way possible inside the housing 27 to other components located there, or the movement can be measured or scanned. The other components can be in contact with or attached to the inside of the diaphragm, or the movement of the diaphragm can be detected without contact. Thus, the movement of the diaphragm can be measured or detected in any way possible. Fig. The cavity 32 formed in 11 must be closed and the movement of the membrane must be detected by a pressure sensor.

[0034] Based on Fig. Figure 12 shows how such a component 26 is integrated into the wall of the housing 15. As the figure shows, the recess 33 in the wall of the housing 15 of the handle 10 is designed so that the housing 27 of the component 26 can be inserted there from the outside, such that the annular surrounding wall section 19 projects radially beyond the recess 33 and rests on the wall of the housing 15. The welding then takes place circumferentially between the wall section 19 and the housing 15; the circumferential weld seam is in Fig. 12 marked with 34.

[0035] Based on the Fig. 13 and Fig. Figure 14 shows how a diaphragm 16 can be integrated into a wall that either forms part of the housing 15 forming the handle 10 or is part of the assembly 26, i.e., is integrated into the wall of the housing 15 by welding as a switch module. The diaphragm 16 is connected to the housing 27 at the edge of the annular flat wall section 19, i.e., on its outer circumference, by means of a weld seam 34. The flat wall section 19 lies flush with its rear side, i.e., the side facing the housing 27, in a recess on the outside of the housing 27, supported on the rear side by the housing 27, namely against the flat surface 35. In the area of ​​the diaphragm 16, in particular the corrugated section 18 and the pressure surface section 17, the cavity 32 is formed, which ensures the necessary clearance for the movement of the diaphragm and accommodates at least one switching contact.This allows the movement of the membrane 16 in the edge area 19 to be minimized, thus increasing the fatigue strength of the weld seam and therefore the tightness of the assembly.

[0036] The assembly 26 consists of three components: the actual housing 27, the diaphragm 16, and a holder 29 or circuit board with the switching contacts 28. To further prevent stress on the weld seam 34 caused by actuation of the switch, i.e., by pressure on the diaphragm 16 or when the diaphragm 16 is reset, an adhesive bond can be provided in the area of ​​the flat surface 35 of the recess and the annular wall section 19 of the diaphragm 16.

[0037] Based on the Fig. The variant shown in sections 16-18, which differs in its basic structure from the one based on the Fig. In accordance with the variant described in sections 13-15 above, eight circular openings 36 are arranged on an annular path within the planar surface 35 of the housing 27. These openings 36, in the form of bores, serve to introduce adhesive 37 after the weld 34 has been applied, i.e., after the membrane 16 has been joined to the housing 27. The adhesive is drawn by capillary action into any gaps formed by thermal influence and, moreover, creates a connection in the area of ​​these openings 36 between the wall section 19 of the membrane 16 and the housing 27, thus protecting the weld 34 from stresses caused by movement of the membrane.

[0038] Based on the Fig. Figures 19-21 show an embodiment in which the diaphragm 16 is integrated almost flush with the wall of the housing 15. A circuit board 38 is arranged below the diaphragm 16, with contact 39 located on the top of the board. A conductor 40 extends from the underside of the circuit board and leads to contact 39. When the diaphragm 16 moves towards the circuit board 38 and thus towards contact 39, the latter is connected to the potential of the housing 15, thereby triggering a switching operation. In the illustrated embodiment, a support wall 41 is provided in the housing wall 15, which supports the circuit board 38 towards the interior of the housing.

[0039] Based on Fig. Figure 22 shows a variant embodiment in which a snap disc 42, also made of metal, is arranged between the diaphragm 16 and the circuit board 38 with the contact 39 located thereon. This snap disc ensures that when pressure is applied to the diaphragm 16, it springs into the position with a distinct click when a certain force is exceeded. In this position, the contact 39 is connected to the potential of the housing 15, 27 via the metallic diaphragm 16 and the snap disc 42 located beneath it, which is also made of metal. This clearly audible click also occurs when the diaphragm 16 is relieved of pressure and moves into the position in Fig.The initial position shown in Figure 22 returns together with the snap disc 42. This embodiment illustrates that the diaphragm 16 does not necessarily have to be designed as a snap disc itself, but can also be arranged as a separate component lying beneath the diaphragm 16. The latter embodiment has the advantage that the components can be functionally better adapted to the respective purpose. Reference symbol list 1 switch 2 switches 10 Handling of an endoscope 12 shaft 14 Supply line 15 Handle housing 16 Membran 17 Print area section 18 wavy section 19 ring-shaped flat wall section 20 Membran 21 depression 22 Switching contact 23 Wall section 24 bracket 25 Contact 26 building units, modules 27 cases 28 Switching contacts 29 bracket 30 electrically conductive foil 31 electrically insulating film 32 cavities 33 Exclusion 34 weld seam 35 Plan area 36 breaches 37 Adhesive 38 circuit boards 39 contacts 40 lines 41 Retaining wall 42 Snap disc

Claims

Medical instrument or device with a housing (15) and with at least one electrical or electronic switch (1, 2) arranged therein, which can be mechanically actuated from outside the housing (15), wherein the switch (1, 2) has a diaphragm (16) for actuation, which is part of a metallic wall section that is hermetically integrated into the housing wall, characterized in that the metallic wall section integrated into the housing wall has a ring section (19) surrounding the diaphragm (16) which is supported on the housing wall, wherein the switch (1, 2) is designed as a unit (26) with a switch housing (27) which is closed off on one side by the diaphragm (16) and which forms the metallic wall section integrated into the housing wall. Instrument or device according to claim 1, wherein the housing (15) is a metal housing (15) and the diaphragm (16) is a metallic diaphragm (16) that forms part of the housing wall or is part of the metallic wall section that is metallurgically bonded to the housing wall by soldering or welding. Instrument or device according to one of the preceding claims, wherein the membrane (16) has a preferably central pressure surface section (17) surrounded by a section (18) with a cross-sectionally wave-shaped shape. Instrument or device according to one of the preceding claims, wherein the metallic wall section with the diaphragm (16) is made of preferably corrosion-resistant spring steel. Instrument or device according to one of the preceding claims, wherein the diaphragm (20) has a stable position in which the switch is ready to be actuated and a metastable position in which the switch is actuated, wherein the diaphragm automatically returns to the stable position when not actuated. Instrument or device according to one of the preceding claims, wherein the membrane (20) is formed in a convex shape towards the outside, at least in sections. Instrument or device according to one of the preceding claims, wherein at least one section of the membrane (16, 20), preferably the button, is formed projecting towards the housing wall. Instrument or device according to one of the preceding claims, wherein the diaphragm is designed as a snap disc or a snap disc (42) is arranged under the diaphragm (16). Instrument or device according to one of the preceding claims, wherein the diaphragm (20) also forms an electrical part of the switch, in particular a switching contact (22). Instrument or device according to one of the preceding claims, wherein the ring section (19) is firmly connected to the housing wall by gluing. Instrument or device according to one of the preceding claims, wherein two switches (1, 2) with bistable diaphragms are arranged side by side and coupled to each other within the housing.

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