Surgical Instrument Handpiece

Abstract

The present invention relates to a surgical instrument handpiece (1) for a surgical instrument, a corresponding surgical instrument, a corresponding medical product set having the surgical instrument handpiece (1) in combination with at least one accessory, a corresponding rinsing device, and a corresponding cleaning method for flushing the interior of the surgical instrument handpiece (1). The surgical instrument handpiece (1) comprises a handle portion (7) that is proximally manipulated by an operator and a shaft portion (8) that extends distally and longitudinally from the handle portion (7). A tool is or can be placed in a distal outlet opening (40) at the distal end of the shaft portion (8) opposite the handle portion (7) by a user. The shaft portion (8) is characterized by having at least one narrowed distal tip (10) with a reduced cross-sectional area in the region of the distal outlet opening (40).

Description

[Technical Field]

[0001] The present disclosure relates to surgical tools in the broadest sense, in particular surgical instrument handpieces used to receive or drive rotatable tools such as cutters, drills, or grinding heads. The present disclosure also relates to such surgical instruments as well as corresponding medical products, which have a surgical instrument handpiece combined with at least one accessory. Furthermore, a corresponding rinsing device, such as a cleaning and disinfection unit or a thermal disinfector, and a corresponding cleaning method for vigorously cleaning the interior of the surgical instrument handpiece are proposed. [Background technology]

[0002] In modern minimally invasive surgery, particularly in neurosurgery and spinal surgery, it is known to use surgical instrument handpieces, for example, for manipulation of bone, cartilage, vertebrae, etc. For example, DE 10 2013 111 194 A1, filed by the same applicant and incorporated herein by reference, refers to surgical instrument handpieces according to the preamble of the claims. Here, typically, each surgical instrument handpiece comprises at least one receiving part, coupling part, or interconnection part for a connectable, preferably rotatably drivable, tool. Medical applications in which surgical instrument handpieces are used include arthroscopy and arthroscopic surgery for examination and / or treatment of joints, orthopedic interventions or operations, spinal surgery, maxillary surgery, neurosurgery, etc.

[0003] During use of a surgical instrument (or instrument handpiece), the distal end of the instrument (or instrument handpiece) comes into contact with organic and inorganic matter, such as body fluids and bone abrasions. These organic and inorganic matter tend to accumulate or settle on and / or within the instrument (or instrument handpiece) in the form of deposits or deposits. For this reason, the use of reusable surgical instruments (or instrument handpieces) requires appropriate preparation or treatment, particularly cleaning and / or disinfection, before and / or after each use. During this preparation or treatment, any dirt that may be present in or on the instrument is removed so that the instrument can be sterilized and used again.

[0004] In particular, cleaning of the lumens or hollow portions of instrument handpieces, as well as their interior surfaces and / or components, is particularly difficult. For this reason, instrument handpieces or hollow portions of instrument handpieces are vigorously cleaned with a cleaning fluid, particularly a cleaning solution. By vigorously cleaning the interior with the cleaning fluid, dirt particles that have accumulated on the interior surfaces and / or components of the hollow portions or instrument handpiece are dislodged and expelled from the hollow portions or instrument handpiece.

[0005] In this process, cleaning of intermediate spaces in hollow parts of instrument handpieces, and in particular the distal ball bearings (facing the patient) for receiving parts of rotatably drivable tools such as cutters and drills, has proven to be particularly difficult: due to its low resistance, the cleaning fluid, when flowing through the instrument handpiece, flows almost exclusively through or along the inner surface of the inner ring of the distal ball bearing, with the result that the balls, cage and intermediate spaces of said ball bearing are less effectively cleaned.

[0006] This problem has already been addressed in the prior art. For example, the applicant's published patent application bearing application number DE 10 2018 133 503.2, the disclosure of which is incorporated herein by reference, discloses a separate water flushing device that includes or consists of a shaft-type water flushing insert for internal cleaning of an instrument handpiece of a surgical instrument, in particular for cleaning a distal ball bearing in the interior space of the instrument handpiece. In doing so, the proposed water flushing device is inserted into or attached to the tool receiving portion or tool receiving shaft of the instrument handpiece for cleaning after the instrument handpiece has been used in surgery. Summary of the Invention [Problem to be solved by the invention]

[0007] Although the above solutions presented from the prior art are convincing in terms of the achievable cleaning efficiency, they still suffer from the following drawbacks: in addition to the instrument handpiece, together with the water-cleaning device disclosed therein, a separate device, namely a shaft-type water-cleaning insert, must be provided, and this shaft-type water-cleaning insert must be inserted into the instrument handpiece before the cleaning cycle in a central supply room (CSSD) or a central sterilization or reprocessing unit for medical devices (RUMED); the separate water-cleaning device risks being lost; and the operation and application of the water-cleaning device must be separately described and realized.

[0008] Furthermore, independent of the above-mentioned cleaning aspect, prior art surgical instrument handpieces have further drawbacks in terms of their application in medical care, particularly surgery. Indeed, these drawbacks have a negative impact in terms of the overall dimensions of the shaft or the inter-component dimensions. For example, in minimally invasive surgery, there is a demand for surgical instrument handpieces to be as small as possible, or even smaller and smaller. On the other hand, when it comes to visualizing a surgical procedure or operation inside a patient's body in real time, particularly through endoscopic camera images played on a surgical monitor for the surgeon, prior art instrument handpieces have drawbacks, such as the instrument handpieces obstructing the view or casting shadows on the tissue. Particularly in the field of microsurgery, this obstruction becomes even greater and more dangerous. On the other hand, there is a need for smaller surgical instrument handpieces or a corresponding expansion of the surgical application field, for example, in terms of surgical access in the field of neurosurgery or the operational display itself.

[0009] US2017 / 0120451A1 discloses a surgical instrument handpiece in the form of an assembly for holding a tool. This assembly can selectively reduce and / or eliminate vibrations experienced by the user. Reducing vibrations can also reduce or eliminate chatter at the working end of the tool. For this purpose, a vibration-damping intermediate element is arranged between the shaft portion for receiving the tool and the handle portion of the surgical instrument handpiece. Here, two slightly different inner diameters are disclosed in the transition area of ​​the intermediate element, but these are those in the cross section located proximal to the ball bearing and therefore in the proximal shaft portion within the handle portion. Furthermore, in the prior art, the total input pressure of the cleaning fluid (in the sense of a pressure difference or excess pressure compared to atmospheric pressure) is provided from an external source proximal to a rinsing device, such as a cleaning and disinfection unit, to several connected instrument handpieces to be cleaned. However, this total input pressure is proportionally distributed according to the number of instrument handpieces, resulting in a respective rinsing pressure for each instrument handpiece, which is reduced as a result. This should be considered a potential problem. As a result, if the load or charging of the prior art rinse device is (too) high, the respective rinse pressure may unsatisfactorily fall below the minimum required for reliable and sufficient fluid cleaning. This technical drawback of potentially too low rinse pressure may occur particularly in situations where hospital capacity is highly utilized.

[0010] Furthermore, in the prior art, there may be an undesirable situation where the free flow cross section (or internal void volume) of the instrument handpiece through which the flow with irrigation fluid can pass widens from proximal to distal along the longitudinal or flow direction, resulting in a decrease in the mechanical irrigation effectiveness from proximal to distal due to pipe friction and other flow resistance factors in particular, in addition to general flow pressure losses.

[0011] The present invention is therefore based on the object of creating a surgical instrument handpiece for a surgical instrument that overcomes the above-mentioned drawbacks of the prior art. First, a safer surgical handpiece is (alternatively) promoted that can be cleaned or sterilized by vigorous internal flushing. In particular, the structural design of the instrument handpiece allows for vigorous flushing aimed at the distal ball bearing. A further object is to provide the user with further application areas for the operational display. A further object is to simplify central supply store (CSSD) processes, thereby making them more cost-effective and less error-prone. [Means for solving the problem]

[0012] The above object is solved according to the present disclosure by the features of claim 1. A surgical instrument handpiece for a surgical instrument according to a first aspect of the present disclosure comprises a handle portion proximally manipulated by an operator and a shaft portion extending longitudinally distally from the handle portion. A tool is or can be placed in a distal outlet opening at the distal end of the shaft portion opposite the handle portion by a user (such as an operator or operating room staff). A tool according to the present disclosure refers to any device or unit. The tool allows an operator to manipulate and / or function a patient's body or body parts, implants, etc. The tool is guided by the operator via the instrument handpiece. According to the present disclosure, the shaft portion has at least one constricted distal tip portion with a reduced cross-sectional area in the region of the distal outlet (40). The term "constriction" or "constriction" herein refers to the cross-sectional area at the distal end, particularly the external dimensions between components of the shaft portion, and preferably the internal flow cross-section.

[0013] Hereby, the term "distal" in the sense of the present disclosure refers to the application engineering point of view of an operator or user operating an instrument handpiece according to the present disclosure, and corresponds to the side facing the patient. Accordingly, the term "proximal" refers to the side facing the operator or user, i.e., the side facing away from the patient.

[0014] As a result, according to the present disclosure, the shaft portion is divided into at least two longitudinal portions, namely, a first portion and a second portion having different cross-sectional areas. The first portion, having a smaller first cross-sectional area, is referred to as the constricted distal tip portion of the (entire) shaft portion. The second portion, having a larger second cross-sectional area compared to the first portion, is referred to as the non-constricted portion of the (entire) shaft portion. In other words, in the distal longitudinal direction, the constricted first portion / distal tip portion is adjacent to the shaft portion extending distally from the handle portion / adjacent to the non-constricted portion of the (entire) shaft portion. That is, the first length along which the first portion / distal tip portion extends in the form of a constriction corresponds to a portion of the total length of the (entire) shaft portion, which is referred to as the second length. Therefore, the difference between the (entire) second length and the first length refers to the (remaining) second portion or non-constricted region of the shaft portion.

[0015] As a result, according to the present disclosure, the flow rate of the irrigation fluid and therefore the hydrodynamic irrigation effect is increased due to the narrowed distal flow cross section.

[0016] The structural design of the instrument handpiece according to the present disclosure allows irrigation fluid to be specifically guided from proximal to distal in the flow direction to the distal outlet opening when flushing the interior. Therefore, the majority of the fluid does not flow ineffectively or ineffectively through the relatively large, and therefore minimal, flow resistance openings of the prior art distal ball bearing inner ring. In other words, the present disclosure helps reduce the proportion of irrigation fluid rinse flow that is ineffectively guided or misguided. This occurs when the maintenance fluid pressure over a wide range is sufficient, ideally significantly higher, for effective flushing along the longitudinal axis of the instrument handpiece as the primary flow direction.

[0017] Furthermore, the optimized outer surface shape of the shaft portion narrowing in accordance with the present disclosure at the distal tip advantageously improves the access to vision for the operator during surgery or intervention.

[0018] The present disclosure also supports simplified processing in central supply storage (CSSD), which has a positive effect on the one hand on reducing operational costs and on the other hand on quality assurance or reliability.The new design according to the present disclosure of the distal tip / tip part constituted by the shaft part of the instrument handpiece improves the cleaning effect during manual or mechanical cleaning, especially with regard to the distal ball bearing and / or with regard to the inner surface of the (distal) tip, without the need to insert additional products such as special rinsing devices.

[0019] In the sense of the present disclosure, it is immaterial whether the shaft portion (in particular the first portion / distal tip itself) also comprises further portions with different cross-sectional areas in addition to the at least one narrowed distal tip portion, i.e. further circumferential shaft shoulders and / or shaft steps may be formed.

[0020] Furthermore, it is not important in the sense of the present disclosure what kind of design is used for the connection, preferably located at the proximal end of the handle, or the interface of the instrument handpiece to an external power source or for operating or driving the preferably rotatably drivable tool. Depending on the intended use and the intended tool speed, hydraulic, pneumatic and / or electric drives can be provided or operatively connected.

[0021] Furthermore, within the meaning of the present disclosure, it is not important that the constriction or, respectively, the reduced / narrowed cross-sectional area have a particular configuration. Thus, in this specification, these terms should not be construed as being limited solely to longitudinal configurations having a constant circular cross-section, such as those having a radially circumferential shaft shoulder and / or radial step. Instead, the terms also include any constriction having a cross-section that varies along its longitudinal axis and / or has a non-flat or non-circular shape, such as, for example, an oval, rectangular, convex, and / or concave cross-section. In particular, the constriction may be formed only in an angular segment or may form an asymmetrically decreasing cross-sectional area.

[0022] The dependent claims present preferred further refinements of the invention.

[0023] However, in many cases, a radially constant or circular shaft cross section or constriction may be preferable not only for manufacturing reasons but also from an application point of view, in particular from a flow dynamics point of view.

[0024] Therefore, under the last mentioned aspect, the surgical instrument handpiece is preferably further improved such that the first diameter of the constricted distal tip portion is smaller than the second diameter of the non-constricted region of the shaft portion by a diameter relationship factor of at most 95 percent, preferably at most 85 percent, and more preferably about 79 percent.

[0025] Alternatively or additionally, the first diameter is preferably 3.5 to 5.3 millimeters, preferably 4.0 to 5.0 millimeters, more preferably 4.3 to 4.5 millimeters.

[0026] This may provide a particularly preferred diameter change or constriction in which a second diameter, e.g., the outer diameter of the shaft portion, which is about 5.6 mm, particularly relating to the area where it abuts the handle portion, changes to a first diameter, e.g., the outer diameter of the constricted distal tip, of about 4.4 mm.

[0027] Preferably, the surgical instrument handpiece is further developed such that the first length of the distal tip is between 5 and 40 millimeters, preferably between 10 and 30 millimeters, more preferably between 18 and 22 millimeters.

[0028] Alternatively or additionally, this results in the first length being a length fraction, as related to, compared to, or normalized to the overall second length of the shaft portion, of preferably at least 5 percent, preferably at least 20 percent, and more preferably at least 35 percent.

[0029] In particular, the instrument handpiece may have a distal tip portion having a width of preferably about 4.4 mm extending to a first length of about 20 mm, while a second (overall) length is selected or set according to the application or surgical optimum length for a (total) shaft portion having a width of preferably about 5.6 mm.

[0030] In that respect, it has been experimentally determined by means of exemplary prototypes that such particularly preferred embodiments of the present disclosure represent a further optimized balance of all application technical dimensions or independent groups of technical problems or objectives, i.e., the above-mentioned surgical aspects relate to a first group of technical challenges, and the flow dynamics in the sense of or for the purpose of subsequent cleaning relate to a second group of technical challenges, where the first group relates to a first application period during surgical or operative use, particularly by an operator as a first user, and the second group relates to a second application period after surgical or operative use, particularly by staff in the field of cleaning or sterilizing surgical instruments and tools as a second user.

[0031] However, it goes without saying that the present disclosure is not limited to the particularly preferred embodiments described above, and in particular in the case of miniaturization, deviating dimensions or other absolute and / or relative dimensions may have to be selected or preferred, as is already known from the scientific basis of flow dynamics parameters or quantities.

[0032] Preferably, the transition area, designed as a shoulder from the constricted distal tip to the non-constricted region of the shaft, is rounded and / or tapered and / or chamfered, avoiding any angular or abrupt transition between the first and second portions, which has the advantage of less contamination or tissue trauma during manipulation by the surgeon in the procedure or insertion into the dissected tissue by the surgeon.

[0033] Preferably, the surgical instrument handpiece is adapted to be inserted into a rinsing device, such as a cleaning and sterilization unit. When the interior of the surgical instrument handpiece is vigorously irrigated with a cleaning fluid, preferably a hydrophilic or lipophilic cleaning liquid, in a proximal-to-distal flow direction, the rinsing pressure present at the distal outlet opening is optimized. For this purpose, the aforementioned rinsing pressure is greater than 10 mbar, more preferably greater than 90 mbar, even more preferably greater than 160 mbar, and especially greater than 500 mbar. Alternatively or additionally, the rinsing pressure, relative to, compared to, or normalized to the proximally applied input pressure of the irrigation fluid, is maintained at a rate of at least 20 percent, preferably at least 50 percent, and even more preferably at least 80 percent. In this way, a particularly high cleaning effect can be achieved, which can be verified, in particular, by standardized cleaning test values. These standardized cleaning test values ​​are values ​​used in complex technical knowledge and legal guidelines for the preparation of medical devices.

[0034] This is particularly advantageous for effectively addressing a problem that arises in the prior art with respect to rinse or flow pressure, namely, that rinse or flow pressure decreases significantly in some areas from proximal to distal along the longitudinal direction of the instrument handpiece / along the flow direction (or along the direction of the streamline). This problem in conventional instrument handpieces can be particularly serious when or to the extent that the (internal) flow cross-sectional area is not only not constant but also increases, especially significantly, from proximal to distal along the longitudinal direction of the instrument handpiece / along the flow direction. The continuity equation for (incompressible) flow is A·v=V′=const. In this equation, A represents the (internal) flow cross-sectional area, v represents the (average) flow rate of the irrigation fluid, and V′ represents the (internal) volumetric flow of the irrigation fluid. Therefore, according to the continuity equation for (incompressible) flow, this means that the flow rate (which is negatively related to the flow cross-sectional area) decreases accordingly. As a result, the kinetic energy flow term is reduced (see Bernoulli's equation), which in the prior art also undesirably reduces the mechanical cleaning effect.

[0035] Preferably, the Reynolds number / Re of the throughflow at the constricted distal tip can mark a turbulent flow region, especially above Re=2300. The material values ​​of the cleaning fluid, especially water, are thereby included in the Reynolds number, both as the fluid density and as the fluid's dynamic viscosity. Furthermore, the (average) flow rate v of the cleaning fluid should be used as the fluid flow velocity. Preferably, the diameter of the (flow) cross section through which the flow can pass, more preferably the diameter of the inner surface of the (distal) tip, is thereby defined as the characteristic length of the body (or pipe). This is also called the reference length. The turbulent flow region can provide advantages in terms of particularly powerful cleaning, especially in the case of the most stubborn dirt or contaminants.

[0036] Instead of the Reynolds number indicating a turbulent region at the distal tip of the stenosis, the Reynolds number may particularly preferably indicate a laminar region at the distal tip of the stenosis. Particularly preferably, Re may be between 1000 and 2000. This provides the advantage of a uniform flow through the instrument handpiece according to the present disclosure, while avoiding pulsations and / or fluid-wall interactions. This allows the rinse device to provide a particularly uniform, quiet, and vibration-free cleaning action.

[0037] Preferably, the shaft portion includes an internal roller bearing arrangement, preferably in at least a portion of the region of the narrowed distal tip, for rotatably mounting a positioned or positionable tool, whereby the roller bearing arrangement includes at least one distal roller bearing and at least one proximal roller bearing, whereby the at least one distal roller bearing and the at least one proximal roller bearing are spaced apart by a bearing cage formed continuously therebetween.

[0038] As a result, the present disclosure obviates unfavorable flow behaviors listed in the prior art, including maximum flow throughflow along the cylindrical axis of the shaft or maximum flow throughflow at the center of the second cross-sectional area. The unfavorable flow behaviors in the prior art result from the laws of fluid dynamics of the path according to minimum flow resistance and / or according to a flow condition known as the wall attachment condition, particularly in the case of pipe flow, and / or according to throughflow through the bed ("Pre-Darcy") for the inside of a roller bearing configuration. In other words, as a result of the prior art, there is an unfavorable fluid dynamic distribution of the flow rate (or vector portion from proximal to distal in the longitudinal direction of the instrument handpiece). This distribution has a maximum value at the center of the shaft or along the rotational axis of the instrument handpiece.

[0039] In particular, the total length of the continuously formed bearing cage may be at least 90% of the first length of the distal tip. Alternatively or additionally, the separation length between at least one proximal roller bearing, such as but not limited to its centerline, and at least one distal roller bearing, such as but not limited to its centerline, corresponding to the continuously formed bearing cage may be at least 60%, more preferably at least 70%, and especially at least 78% of the first length.

[0040] A particularly preferred embodiment of the present disclosure, describing a continuously formed bearing cage, particularly effectively overcomes the aforementioned drawbacks of the prior art. In this case, a forced throughflow is provided through the internal roller bearing configuration and / or along the internal surface. Therefore, the mechanical cleaning effect of the cleaning fluid is further enhanced when connected to a rinsing device, particularly a cleaning and disinfecting unit. This results in a reliable and thorough fluid cleaning at the exact points or surfaces where dirt may adhere, and in a highly effective manner. In other words, the cleaning efficiency of the fluid cleaning / rinsing is improved by avoiding situations where the cleaning fluid follows the path of least resistance and escapes to the center. Instead, according to the present disclosure, the cleaning fluid is specifically directed toward the surfaces to be cleaned where the mechanical cleaning effect should occur, i.e., in particular, toward the interior surfaces of the at least one distal roller bearing and at least one proximal roller bearing and / or along the internal surface of the narrowed distal tip.

[0041] In this case, a bearing in which rolling elements, such as balls, cylinders, needles, barrels, or cones, reduce the frictional resistance between the inner and outer rings should be considered a roller bearing (configuration), as opposed to the lubrication in a sliding or friction bearing.

[0042] In embodiments having an internal roller bearing configuration, preferably with a continuously formed bearing cage, there is further provided special, targeted flow control or forced throughflow of irrigation fluid through a gap void volume that occurs or is formed between the inner surface of the (distal) tip and the outer surface of the bearing cage.

[0043] Furthermore, in contrast to the prior art, it may be preferable for (almost) all other possible flow paths (except the gap void volume) of the instrument handpiece to be closed, such as the inner bore through at least one complementary configured component, such as the drive shaft. In other words, forced throughflow occurs exclusively (or entirely) through the gap void volume.

[0044] In particular, the gap void volume may be a ring gap void volume. In this case, more preferably, the inner surface of the (distal) tip and the outer surface of the bearing cage may be designed cylindrically, more preferably concentrically, i.e., arranged on the same central axis. This makes it irrelevant for the present disclosure whether and to what extent certain manufacturing tolerances or adaptations exist. In particular, instead of or in addition to this, the latter may be configured taking into account design / construction criteria and / or operational criteria, preferably the concentricity characteristics and / or machine dynamics parameters of the internal roller bearing arrangement.

[0045] The corresponding (respective flow) cross-sectional area corresponds to the (respective) (ring) gap void volume. Thus, for forced throughflow, a cylindrical ring gap cross-sectional area is formed between the outer ring gap outer diameter and the inner ring gap inner diameter (of a cylindrical inner component, in particular a continuously formed bearing cage). Consequently, the ring gap cross-sectional area is calculated as the (respective flow) cross-sectional area based on the subtraction of the areas of these two circles with the ring gap outer diameter and the ring gap inner diameter, respectively.

[0046] Particularly preferably, the (respective flow) cross-sectional area, in particular the cross-sectional area of ​​the ring gap, does not increase in the flow direction of the irrigation fluid or along the second length of the entire shaft section (from proximal to distal), in particular from the proximal region at the transition to the handle section to the distal region of the proximal roller bearing and / or to the outlet cross-sectional area. In other words, in particular the cross-sectional area of ​​the ring gap may remain constant and / or decrease in the flow direction. It is further preferred that the constriction thereby proceeds continuously / does not have any discontinuities. Thanks to this, sudden changes in flow conditions are avoided. In this way, in particular local dead zones or turbulent or throttling effects, which may be accompanied by a local reduction in mechanical fluid irrigation, are avoided.

[0047] In the preferred embodiment of the inner roller bearing as a continuously formed bearing cage, the bearing cage ring gap cross-sectional area formed around the outer surface of the (central) bearing cage is obtained by subtracting the areas of two circles: one with the diameter of the inner surface as the ring gap outer diameter, and the other with the outer diameter of the bearing cage as the ring gap inner diameter.

[0048] Preferably, the bearing cage ring gap cross-sectional area of ​​the ring gap located at the narrowed distal tip is 3.5 mm 2 less than or equal to about 3 mm, and more preferably 2 It is particularly preferably 2.8 mm or less. 2 The following is the result.

[0049] Alternatively or additionally, the bearing cage ring gap cross-sectional area of ​​the narrowed distal tip may be equal to or less than the free flow cross-sectional area of ​​the proximal region of the surgical instrument handpiece, and in particular, equal to or less than the proximal shaft ring gap cross-sectional area, whereby the proximal shaft ring gap cross-sectional area may be an area at the transition to the handle, said area being proximal to the region of the shaft and / or tool receiving portion of the shaft, and said area being proximal to the proximal roller bearing.

[0050] In particular, the (distal) bearing cage ring gap cross-sectional area may be 85% or less of the proximal shaft portion ring gap cross-sectional area, more preferably 80% or less, and particularly preferably 76.5% or less.

[0051] Thus, alternatively or additionally, in particular the (distal) bearing cage ring gap cross-sectional area may be 150% or less, more preferably 130% or less, and especially preferably about 122% or less of the (proximal) instrument handpiece input cross-sectional area, whereby the instrument handpiece input cross-sectional area is the flow cross-sectional area of ​​the instrument handpiece located in the connection area to the rinsing device and allowing (free) throughflow. In particular, the instrument handpiece input cross-sectional area represents the minimum / bottleneck of the flow cross-sectional area when referring to throughflow through the entire instrument handpiece.

[0052] It is particularly preferred that the flow rate / volume flow and / or flow rate of the irrigation fluid through the at least one distal roller bearing and / or through the at least one proximal roller bearing is increased, in particular the longitudinal vector portion of the flow rate in the longitudinal direction of the shaft or the longitudinal direction of the tip, which has the advantage that zones where the flow rate of the irrigation fluid is only inadequately high with respect to the mechanical irrigation effect and / or dead zones are avoided.

[0053] The increase in flow rate, particularly in the longitudinal vector portion, through or along the internal roller bearing arrangement may be determined or quantified, particularly according to the respective corresponding bearing cage stiffening factor.

[0054] On the one hand, with regard to the primary or first bearing cage augmentation factor, the respective corresponding bearing cage augmentation factor can be determined by comparing or relating the situation according to the present disclosure, i.e., the situation with a constricted distal tip, to the normal situation according to the first identified prior art, i.e., the situation without a constricted distal tip.

[0055] Preferably, the first bearing cage augmentation factor, especially for the distal roller bearing, may be 1.5 or more, more preferably 2.5 or more, and particularly preferably 3 or more. Insofar as the flow rate relative to the quadratic exponent is included in the calculation of the flow kinetic energy term, an increase in the first bearing cage augmentation factor results in a significant increase in kinetic energy and therefore in a significant increase in mechanical cleaning performance. In particular, it is actively achieved that all zones or surfaces to be cleaned are reliably flushed and powerfully cleaned by the fluid.

[0056] On the other hand, the respective corresponding bearing cage augmentation factor can be determined by comparison with or in relation to the situation according to the present disclosure, i.e., the situation with a narrowed distal tip, in terms of the secondary or second bearing cage augmentation factor. The second bearing cage augmentation factor thus indicates, for further preferred embodiments with a continuously formed bearing cage, how said factor further improves the situation according to the present disclosure with a narrowed distal tip portion (without a continuously formed bearing cage). Preferably, the second bearing cage augmentation factor, particularly relevant to the distal roller bearing, may be 1.1 or greater, more preferably 1.5 or greater, and particularly preferably 2 or greater.

[0057] In a preferred embodiment with an internal roller bearing arrangement in the form of a continuously formed bearing cage, the width of the bearing cage ring gap is defined as the reference length for the Reynolds number. Here, the width of the bearing cage ring gap is calculated based on the subtraction of the outer diameter of the bearing cage, as the inner diameter of the ring gap, from the diameter of the inner surface, as the outer diameter of the ring gap. Apart from that, reference is made to all details disclosed above regarding the Reynolds number. In a preferred embodiment, a low Reynolds number is particularly advantageous. In particular, for throughflow, an otherwise (initial) turbulent flow region can be reversed by inserting the bearing cage and the resulting corresponding reduction in the reference length in the laminar flow region.

[0058] Overall, the internal roller bearing configuration, preferably the embodiment with a continuous bearing cage, offers the advantage of further improving the cleaning effect during vigorous cleaning of the interior of an instrument handpiece due to the fact that a special, i.e., targeted, flow control of the cleaning fluid is achieved. In particular, a forced throughflow or forced convection of the cleaning fluid through the at least one distal roller bearing and / or the at least one proximal roller bearing occurs, which ensures a focused flow around the rolling elements. As a result, the presence of a continuous bearing cage results in an even more enhanced hydrodynamic effect. This allows reliable fluid cleaning even during such fluid cleaning operations of a rinsing device, in particular a cleaning and disinfecting unit, equipped with a large number of connected instrument handpieces, i.e., a particularly large number, in particular (almost) all, of input connections, adapters, or flanges. That is, even in the case of a smaller partial volume of the total volume of cleaning fluid available to the rinsing device, divided or separated depending on the number of connected instrument handpieces, a sufficient fluid throughflow and, therefore, a sufficiently strong mechanical cleaning effect is guaranteed.

[0059] As already mentioned above, the surgical instrument handpiece is adapted to be inserted into a rinsing device, such as a cleaning and disinfection unit, so that its interior can be flushed with a flushing fluid, preferably a hydrophilic or lipophilic flushing liquid, in a proximal-to-distal flow direction. In the case of the immediately preceding preferred embodiment of the surgical instrument handpiece (especially with a continuously formed bearing cage), the flushing pressure present at the distal outlet opening is greater than 600 mbar, preferably greater than 700 mbar, and more preferably about 800 mbar. This ensures the most effective flushing in the particularly preferred embodiment described above.

[0060] Preferably, the bearing cage is completely closed, which has the advantage of maximizing the cleaning power for the distal roller bearing 20. Alternatively, the bearing cage is permeable to fluids with a small area-related pore volume fraction. The pore volume fraction may be preferably less than 40 percent, more preferably less than 15 percent, and particularly preferably less than 8 percent. This allows for further optimization in terms of a cleaning effect that is as uniform as possible based on improved flow guidance across and along the bearing cage. The flow guidance can be obtained, for example, by fluid dynamics modeling or by computational methods using finite volume elements of the internal flow space of the instrument handpiece.

[0061] Preferably, the at least one distal roller bearing and / or the at least one proximal roller bearing, preferably all roller bearings of the internal roller bearing arrangement, are equipped with non-spherical rolling elements. It is further preferred that the at least one distal roller bearing and / or the at least one proximal roller bearing are designed as cylindrical roller bearings and / or needle bearings. The rolling elements of cylindrical roller bearings are cylindrical. Cylindrical roller bearings are manufactured with different designs, such as those described in the DIN 5412 standard, the contents of which are incorporated herein by reference. Needle bearings have cylindrical rolling elements, called needles, which have a length significantly greater than the diameter of the rolling elements (a correlation factor of approximately 2.5 or greater). Needle bearings are standardized in the DIN 617 standard, the contents of which are incorporated herein by reference. In these embodiments with non-spherical rolling elements, the roller bearing arrangements are characterized by a high radial load capacity and a flat or compact structural design. Furthermore, when flushing the interior with a flushing fluid, cylindrical roller bearings and / or needle bearings tend to exhibit uneven or pulsating flow behavior caused by the reduced gap channel width between the outer surface of the bearing cage and the inner circumferential surface of the shaft portion, compared to spherical rolling element or ball bearings, resulting in a favorable improvement in the cleaning effect.

[0062] Preferably, the at least one distal roller bearing and / or the at least one proximal roller bearing, preferably all roller bearings in the internal roller bearing configuration, are equipped with ceramic rolling elements or ceramic needles. This improves mechanical strength, particularly the behavior under constant load, which has the positive effect of extending service life and service intervals. Furthermore, the rolling elements may be smaller in size, allowing even flatter rolling element designs. This further reduces the gap channel width between the outer surface of the bearing cage and the inner circumferential surface of the shaft section. It is also conceivable to use a fully ceramic bearing. In particular, in addition to the rolling elements, the bearing ring is also made of ceramic material.

[0063] According to a second aspect of the present disclosure, a surgical instrument is proposed, comprising an instrument handpiece of the present disclosure and a tool, preferably rotationally driven and / or rotatably drivable. Preferably, the tool comprises a cutter, such as a fine or coarse diamond milling cutter, a ("twin cut") ball cutter, a pin cutter, a spiral or straight craniotomy cutter, and / or a drill, such as a spiral drill, and / or a burnishing head and / or a swivel knife. Furthermore, the tool may be a stationary tool, such as an electrocautery, a cautery, or a laser. The nominal diameter of the tool may preferably range from 1.0 mm to 6.0 mm.

[0064] According to a third aspect of the present disclosure, a medical product set is proposed, comprising at least one first instrument handpiece according to the present disclosure in combination with at least one accessory part. Preferably, the medical product set is an assortment of medical tools for an operator, such as a surgeon. First, the instrument handpiece according to the present disclosure is preferably combined with a surgical instrument according to the present disclosure. Alternatively or additionally, the combination of the medical product set with the at least one accessory part includes a plurality of different medical tools, particularly rotationally driven and / or rotatably driven medical tools. This preferably refers to an assortment of tools with different functions and types, such as drills, cutters, etc., and / or straight and / or curved tools, and / or tools with different sizes, such as pediatric, standard, short, long, etc., and / or tools according to hardness and / or material. Alternatively or additionally, the combination of the medical product with the at least one accessory part includes a second instrument handpiece according to the present disclosure. The first and second instrument handpieces have different first diameters and / or different second diameters and / or different first lengths and / or different second lengths. Alternatively or additionally, the combination with the at least one accessory part includes a tool wrench for inserting a corresponding tool into the instrument handpiece.

[0065] Such product sets have the special advantage that the manufacturer guarantees that the accessory parts that users, such as operators and / or hospital staff, will use may be matched and adapted so that they are optimally combined and functionally compatible with one another. Such product sets are considered particularly useful by users. Further application advantages are reflected in increased flexibility and safe operation, as well as improved hospital logistics processes in the central supply department (CSSD) as well as in the preparation for surgery.

[0066] According to a fourth aspect of the present disclosure, a rinsing device, such as a cleaning and disinfection unit, is proposed. The rinsing device is adapted to vigorously clean the interior of an instrument handpiece according to the present disclosure. Cleaning and disinfection units (CDUs), also known as thermal disinfectors, are used for machine-based decontamination, reprocessing, or sterilization of reusable medical products, such as surgical instruments. As a result, a central supply department (CSSD) is provided with a device optimally tailored by the manufacturer for cleaning instrument handpieces according to the present disclosure.

[0067] According to a fifth aspect of the present disclosure, there is provided a cleaning method for flushing the interior of an instrument handpiece in a proximal to distal flow direction with a rinse device according to the present disclosure, thus improving cleaning efficiency and the degree of sterilization achieved.

[0068] Therefore, preferably, the irrigation method according to the present disclosure is further hydrodynamically optimized and improved, preferably so that the flow lines of the irrigation fluid through the proximal roller bearing also include flow lines along the outer surface of the continuously formed bearing cage and / or flow lines through at least one distal roller bearing, thereby further avoiding incomplete or inadequate flow of the irrigation fluid.

[0069] Finally, it should be noted that the instrument handpiece according to the present disclosure is not limited to use in surgery alone. The present disclosure is equally advantageously applicable to similar medical applications, particularly various dental and orthopedic situations and procedures, as well as various diagnostic or examination methods. Fields of application include human medicine and veterinary medicine. The concept according to the present invention is particularly directed to the application of instrument handpieces for receiving rotatably mounted tools, where reliable cleaning through vigorous internal flushing after tool use or removal is crucial for reuse, and / or where the smallest possible distal structural design is essential.

[0070] The scope of protection of the present disclosure is given by the claims and is not limited by the features described in the specification or shown in the drawings. [Brief explanation of the drawings]

[0071] [Figure 1] FIG. 1 is a side view, slightly oblique, of an embodiment of a prior art instrument handpiece (without tools). [Figure 2] FIG. 1 is a side view of an instrument handpiece (without tools) in a prior art embodiment. [Figure 3a] FIG. 1 shows a distal detail of a cross-sectional view of an instrument handpiece (without tool) in a prior art embodiment, particularly showing the internal roller bearing arrangement for the tool. [Figure 3b] 3a, showing a schematic representation of the hydrodynamic flow lines, in particular the internal throughflow of the irrigation fluid. [Figure 4] FIG. 1 is a side view, at a slight angle, of an instrument handpiece (without tools) according to the present disclosure in a preferred embodiment. [Figure 5] FIG. 1 is a side view of an instrument handpiece (without tools) according to the present disclosure in a preferred embodiment. [Figure 6a] 1 shows a distal detail of a cross-sectional view of an instrument handpiece (without tool) according to the present disclosure in a preferred embodiment, particularly showing the internal roller bearing arrangement for the tool. [Figure 6b] 6a, showing a schematic diagram of the hydrodynamic flow lines, particularly the internal flow through an instrument handpiece (without tools) according to the present disclosure, with irrigation fluid according to a preferred embodiment. [Figure 7] 1 is a side elevational view, at a slight angle, of a preferred bearing cage for use within an instrument handpiece according to the present disclosure, showing the bearing cage as a separate component, corresponding to a preferred embodiment; FIG. [Figure 8a]1 is a first cross-sectional view of a prior art embodiment of an instrument handpiece (without a tool) showing the tool receiving area of ​​the shaft, which is proximal to the proximal roller bearing. [Figure 8b] 8b is a second cross-sectional view of an instrument handpiece (without a tool) in a prior art embodiment, taken further distally than the first cross-sectional view of FIG. 8a, showing the proximal roller bearing in the shaft portion. [Figure 9] 1 is a cross-sectional view of an instrument handpiece according to the present disclosure showing a region proximal to the shaft portion at the transition to the handle portion; [Figure 10a] 1 is a first cross-sectional view of an instrument handpiece of the present disclosure (without a tool) in accordance with a preferred embodiment, showing the tool receiving area of ​​the shaft portion, which is proximal to the proximal roller bearing. [Figure 10b] FIG. 10B is a second cross-sectional view of the instrument handpiece of the present disclosure (without tool) according to a preferred embodiment, taken further distal than the first cross-sectional view of FIG. 10A, showing the central region of the bearing cage of FIG. 7 at the narrowed distal tip. DETAILED DESCRIPTION OF THE INVENTION

[0072] Description of the embodiment Embodiments of the present disclosure will now be described with reference to corresponding Figures 4 to 6b, 7, and 9 to 10. In the description, the embodiments of the present disclosure will be contrasted with prior art embodiments corresponding to Figures 1 to 3b and 8a and 8b. Further details, features, and advantages of the present disclosure will become apparent from this description.

[0073] Insofar as the instrument handpiece of the present disclosure corresponding to the preferred embodiments according to Figures 4 to 6b and Figures 10a and 10b is identical to the prior art embodiments corresponding to the analogous Figures 1 to 3b and the analogous embodiments according to Figures 8a and 8b, or insofar as the characteristic features according to the present disclosure are not described, reference is made to the introductory descriptions and names of the prior art to avoid repetition.

[0074] 1 and 2 are a side view and a side elevational view, respectively, of an instrument handpiece (without a tool) according to a prior art embodiment. The surgical instrument handpiece 1 for a surgical instrument includes an integrally formed handle portion 7 that can be manipulated proximally / away from the patient by an operator (not shown), and a shaft portion 8 that extends longitudinally from the handle portion in a distal / patient-facing direction. This allows a user to place a tool (not shown), such as a diamond milling cutter or spiral drill, at the distal end of the shaft portion 8 opposite the handle portion 7, in a cylinder bore 40, which is the distal exit opening of the shaft portion 8. Thus, the tool (not shown) typically includes a tool head, such as a drill head, cutter head, grinding head, or burnishing head, and a tool shaft that is inserted into the cylinder bore 40.

[0075] At its proximal end (the end facing away from the patient), the instrument handpiece 1 also comprises a connection 5. As known from the prior art, the connection 5 allows the instrument handpiece 1 to be connected to a torque transmission train, a drive unit, an energy supply unit or the like.

[0076] Between the distal end cylinder bore 40 adapted to receive a tool and the connecting portion 5 is formed a handle portion 7 having surface features 12 (knobs, grooves, etc.). Adjacent to the surface feature 12 in a distal direction is a cylindrical shaft portion 8. The surface feature 12 comprises radial and axial recesses with projections formed between the recesses. The instrument handpiece 1 is typically gripped by an operator at the handle portion 7 and is manipulated by the handle portion 7 during use.

[0077] The cylindrical shaft portion 8 is formed to have a constant second diameter D2 (see FIG. 2).

[0078] Also, Figures 3a and 3b each show the same distal detail of a cross-sectional view of a prior art instrument handpiece (without tool): one (Figure 3a) without flow through it, in the sense of a normal manufacturing drawing, and the other (Figure 3b) a hydrodynamic schematic with fluid flowing through it. For clarity, only the flow line S is labeled in Figure 3b, since the following description refers to the names of the corresponding labeled components in Figure 3a.

[0079] 3a and 3b show the entire internal roller bearing arrangement, which is provided for rotatably positioning a rotatably drivable tool (not shown) within the instrument handpiece 1, particularly within the shaft portion 8. In this regard, the views of FIGS. 3a and 3b are interrupted, as indicated by the dashed-dotted line (at the far right of the drawings). The entire roller bearing arrangement comprises a distal ball bearing pair 20 (located on the left side of the drawings) formed from two distal roller bearings, and a proximal roller bearing pair 22 (located on the right side of the drawings) formed from two proximal roller bearings 22. Thus, all four individual ball bearings, i.e., the distal ball bearing pair 20 and the proximal ball bearing pair 22, have the same structure. To achieve this, each individual ball bearing comprises a plurality of balls 30 as spherical rolling elements that roll between or on a respective inner ring 26 and a respective outer ring 24, thereby spacing the rings apart. Each outer ring 24 is fitted onto the distal inner cylindrical surface 33 of the shaft portion 8 .

[0080] Also visible in the cross-sectional views of Figures 3a and 3b is an internal tool receiving portion 19 for holding or supporting a tool shaft (not shown), and a guide bushing 32 at the proximal end of shaft portion 8. A tool (not shown) to be inserted into a cylinder bore 40 at the distal tool end is preferably interchangeably held or coupled to tool receiving portion 19 and guide bushing 32 of instrument handpiece 1 and is rotatably drivable via proximal connection portion 5 (see Figures 1 and 2).

[0081] The fluid dynamics diagram in Figure 3b shows the flow through the instrument handpiece 1 using straight streamlines S. This flow through condition occurs when the instrument handpiece 1 is inserted into a rinsing device (not shown), such as a cleaning and disinfection unit. The longitudinal streamlines S represent the flushing of the interior of the instrument handpiece 1 with a flushing fluid, preferably a hydrophilic or lipophilic flushing fluid, in a proximal-to-distal flow direction. In this case, the streamlines S exit through the distal outlet opening 40 (on the left side of the diagram).

[0082] The flow through the entire roller bearing configuration, from the proximal ball bearing pair 22 (on the right side of the figure) to the distal ball bearing pair 20 (on the left side of the figure), can be clearly seen by the path of flow line S in FIG. 3b. Initially, the forced flow through the proximal structural design of the proximal ball bearing pair 22, and the resulting hydrodynamically effective cleaning, occurs by flowing around the corresponding balls 30. However, after exiting the proximal ball bearing pair 22, downstream / distal flow follows a path substantially toward the central axis of the shaft portion (following the path with the least flow resistance). Ultimately, most of the cleaning fluid passes through the relatively large cylindrical openings or bores in the paired inner rings 26, 26 of the distal ball bearing pair 20 and exits the interior of the shaft portion 8 through the distal outlet opening 40. In this case, there is little flow through the distal ball bearing pair 20 (on the left side of the figure) as in the prior art, and therefore the distal ball bearing pair 20 is not properly cleaned (by the fluid).

[0083] The above-described path or flow conditions of the flow through the instrument handpiece 1 from proximal to distal in a prior art embodiment are explained in more detail with reference to Figures 8a and 8b. For example, Figure 8a is a first cross-sectional view of a conventional instrument handpiece 1 (without a tool) taken through a cylindrical shaft portion 8 having a constant second diameter D2 (see also Figure 2). Here, the first cross-sectional view of Figure 8a is taken through a region of the tool receiving portion 19 (see also Figure 3a) located proximal to the proximal roller bearing 22 (Figure 2). Figure 8b is a second cross-sectional view of the conventional instrument handpiece (without a tool) taken distally, or further downstream in the flow direction, compared to the first cross-sectional view of Figure 8a. Thus, the second cross-sectional view of Figure 8b takes through the proximal roller bearing 22 in the shaft portion 8 having the second diameter D2.

[0084] Therefore, in the first and second cross-sectional views (prior art: Figures 8a and 8b), particular reference is made to the fluid dynamics schematic diagram (prior art: Figure 3b) which shows, using straight streamlines S (or in fact two streamlines selected by way of example from among several), the state of the instrument handpiece 1 as the fluid flows through it.

[0085] This causes the streamlines S to exit the page associated with the illustration of the cross-sections (prior art: Figures 8a and 8b), i.e. (ideally) as points towards the viewer. Each streamline S is (exemplary / selectively) depicted as if it were the arrowhead of the corresponding flow vector of the volume of fluid passing through the page.

[0086] Thus, each dotted streamline S in the cross-sectional view represents a cross-sectional area through which the flow passes, or an open cross-sectional area, or a corresponding cross-sectional area of ​​the flow. In other words, a point represented by a streamline S in one of the cross-sectional views represents a cross-sectional area (recognizable between the contour line or the edge of the dotted body, or a separate cross-sectional area) through which the flow is available. Consequently, a cross-sectional area exists in the fluid path to and from the input connection of the instrument handpiece 1 for or during flushing with a cleaning fluid by a rinsing device (not shown), preferably a cleaning and disinfecting unit. From the first cross-sectional view of FIG. 8a, it can be inferred that the cross-sectional area AR of the cylindrical ring gap is formed between the outer cylindrical ring gap outer diameter d-R1 and the inner ring gap inner diameter d-R2 for the throughflow (represented by the dotted exiting streamline S). Therefore, the ring gap cross-sectional area AR is calculated as the cross-sectional area (for each flow) based on the subtraction of the area of ​​the circle having the ring gap outer diameter d-R1 and the area of ​​the circle having the ring gap inner diameter d-R2. The ring gap cross-sectional area AR as shown in Figure 8a is, for example, 2.4 mm 2 may be.

[0087] The second cross-sectional view in Figure 8b shows the downstream / distal flow situation. Here, in the proximal roller bearing 22, the throughflow flows through two flow spaces or respective cross-sectional areas that are separated by the inner ring 26. This allows these to together form the total roller bearing flow cross-section (e.g., 8.5 mm ) as explained below. 2 ) The proximal roller bearing 22 is depicted as having seven balls 30 as rolling elements, which roll down between an inner ring 26 having an inner ring diameter d-26 and an outer ring 24 having an outer ring diameter d-24 fitted to the shaft portion 8. A portion of the throughflow is distributed across the bore cross-sectional area AB (e.g., 4.5 mm) according to the bore diameter dB (e.g., 2.4 mm). 2) through the center of the cylindrical bore interior space of the inner ring 26 (as shown by the exiting streamline S as a dot).

[0088] The other part of the throughflow is the (free) roller bearing cross section A-22 (e.g., 4.0 mm 2 ) through the roller bearing interior space of the proximal roller bearing 22, which is formed between the inner ring 26 and the outer ring 24. There are no balls 30 (seven). Two point-like exiting streamlines S are shown.

[0089] The distribution of the flow rate (in the longitudinal direction of the instrument handpiece 1) occurs hydrodynamically according to the laws of fluid mechanics of a flow path according to minimum flow resistance and / or according to a flow condition known as wall attachment condition, particularly in the case of pipe flow, and / or according to the throughflow through the bed ("Pre-Darcy"). This distribution has a maximum value within the bore cross-sectional area AB. In contrast, only a small portion of the throughflow, or a relatively small portion of the other portion, compared to said portion of the throughflow, will pass through the roller bearing cross-sectional area A-22.

[0090] In other words, the structure of the conventional instrument handpiece 1 disadvantageously creates a situation where, when there is a throughflow of irrigation fluid therethrough, there is a low, weak, or slow throughflow, particularly through the roller bearing (or proximal roller bearing 22, which is representatively described here hydrodynamically). In the prior art, such a situation occurs when the flow cross-sectional area is proximal (ring gap cross-sectional area AR, e.g., 2.4 mm 2 ) and distal (total roller bearing flow cross section, e.g. 8.5 mm 2), which is considered to be particularly disadvantageous in that the flow rate increases significantly towards the center of the flow path. As a result, there is a risk that the mechanical cleaning effect of the cleaning fluid will not be adequately achieved. In particular, the mechanical cleaning effect is determined as a hydrodynamic parameter according to the kinetic energy of the cleaning fluid, which parameter incorporates the square of the flow rate.

[0091] The aforementioned drawback of the resulting reduced throughflow in the roller bearings and therefore reduced cleaning effectiveness is even greater with respect to the technical objectives of hygiene, in particular with respect to completely reliable sterilization, since the large surface of the roller bearings provides a particularly large surface area for the adhesion of contaminants such as bacteria, biofilms, etc.

[0092] Therefore, based on the first and second cross-sectional views of a conventional instrument handpiece in Figures 8a and 8b, the drawbacks of the prior art discussed above with reference to Figure 3b are particularly evident in terms of the inadequate (fluid) cleaning effect of the throughflow visualized by the flow line S.

[0093] The present disclosure remedies these shortcomings. Figures 4-7 show different views of an embodiment of an instrument handpiece 1 according to the present disclosure. For example, Figures 4 and 5 show a slightly angled side view and a side elevational view (similar to Figures 1 and 2 for the prior art) of an instrument handpiece (without a tool) according to the present disclosure in a preferred embodiment.

[0094] Unlike the prior art, the shaft portion 8 comprises a narrowed distal tip 10 in the region of the distal outlet opening 40 (on the left in FIGS. 4-6b). The distal tip 10 narrows / reduces from the second diameter D2 of the shaft portion 8 to a smaller first diameter D1 (see FIG. 5). In other words, the preferred embodiment of the instrument handpiece according to the present disclosure shown in FIGS. 4-7 differs from the conventional instrument handpiece according to the prior art shown in FIGS. 1-3b in that the longitudinal shaft portion 8 having the second diameter D2 comprises a narrowed distal tip 10 in the distal region of the cylinder bore 40 as the distal outlet opening.

[0095] As shown in curly brackets in Figure 4, the first length L1 of the distal tip 10 occupies a distal portion of the (total) second length L2 of the (total) shaft portion 8. Between the distal tip 10 having the first diameter D1 and the shaft portion 8 having the second diameter D2, a shoulder or ramp step is formed circumferentially as a gradually tapered or chamfered transition region 11 (see Figure 5).

[0096] Also, Figures 6a and 6b (similar to Figures 3a and 3b for the prior art) each show the same distal detail in a cross-sectional view of an instrument handpiece (without a tool) according to the present disclosure in a preferred embodiment, one without throughflow in the sense of a manufacturing drawing (Figure 6a), and the other with fluid flowing therethrough (Figure 6b). For clarity, only the flow lines S and the cross-sectional exit area A for the flow are labeled in Figure 6b, since the following description refers to the names of the corresponding labeled components in Figure 6a.

[0097] 6a and 6b show in particular an internal full roller bearing arrangement, which is provided for rotatably positioning a rotatably drivable tool (not shown) inside the instrument handpiece 1, in particular at the distal tip 10 of the shaft portion 8. The views of FIGS. 6a and 6b (as in the previously mentioned FIGS. 3a and 3b) are interrupted (at the right edge of the drawing) as indicated by a dashed line. The full roller bearing arrangement comprises a distal needle bearing (or cylindrical roller bearing) 20 (on the left side of the drawing) and a proximal needle bearing (or cylindrical roller bearing) 22 of identical construction (on the right side of the drawing). To this end, the distal needle bearing 20 and the proximal needle bearing 22 each comprise a plurality of preferably ceramic needles 30 as elongated or longitudinal non-spherical rolling elements, distributed in uniform angular segments around their respective circumferences. Each needle 30 is set or positioned within a corresponding plurality of longitudinal grooves 35 in the bearing cage 50 for rotational movement about the needle's central longitudinal axis. The distal needle bearing 20 and the proximal needle bearing 22 are spaced apart in the longitudinal direction of the shaft portion 8 by the cylindrical bearing cage 50, which is inserted into the cylindrical internal bore of the distal shaft portion 10. In this case, the respective needles 30 of the distal needle bearing 20 and the proximal needle bearing 22 roll on or within the cylindrical internal surface 33 of the distal tip 10 or of the shaft portion 8. As is consistent with the prior art, an internal tool receiving portion 19 is recognizable at the proximal end of the shaft portion 8, along with a guide bushing 32, for holding or supporting a tool shaft (not shown).

[0098] FIG. 6b shows a schematic diagram of the hydrodynamic flow lines S, as in FIG. 3b already shown for the prior art. Therefore, to avoid repetition, reference is made to the description of FIG. 3b, unless differences from the prior art are affected. In contrast to FIG. 3b, FIG. 6b shows a state in which a fluid flow according to the present disclosure is present during an internal flow-through with a cleaning fluid through an instrument handpiece (without tools) according to the present disclosure, corresponding to a preferred embodiment. Such a state in which a fluid flow according to the present disclosure is present is preferably provided or can be realized by the fact that the instrument handpiece 1 according to the present disclosure is inserted into a rinsing device (not shown), e.g., a cleaning and disinfection unit, according to the present disclosure. The longitudinal flow lines S represent the flushing of the interior of the instrument handpiece 1 with a cleaning fluid, preferably a hydrophilic or lipophilic cleaning liquid, in a proximal-to-distal flow direction (from right to left in the figure). In this case, the flow lines S exit the distal outlet opening 40 (located on the left side of the figure) of the constricted distal tip 10. The constricted distal tip 10 has a correspondingly reduced flow exit cross-sectional area A.

[0099] The path of flow line S in Figure 6b clearly shows the throughflow according to the present disclosure, which also passes through the distal needle bearing 20 as a distal roller bearing. The flow line extends along substantially the entire length of the shaft portion 8, and particularly along the first length L1 of the distal tip, along the inner surface 33 of the distal tip 10 or of the shaft portion 8. In particular, the flow takes a downstream path substantially toward the central axis of the shaft portion only after also passing through the distal needle bearing 20, or just before exiting the distal outlet opening 40 with reduced outlet cross-sectional area A. Thus, according to the present disclosure, the distal needle bearing 20 as a distal roller bearing is also subjected to hydrodynamically effective cleaning (by fluid).

[0100] This is because the constricted distal tip 10 of the present disclosure increases the flow rate and pressure due to the reduced cross-sectional exit area A at the distal tip 10 of the instrument handpiece 1 for improved cleaning. This is caused by the change in diameter of the distal tip 10 from an outer diameter of 5.6 mm, an exemplary second diameter D2, to an exemplary first diameter D1 of 4.4 mm over the first 20 mm region, an exemplary first length L1.

[0101] Furthermore, the special structural design of the bearing cage 50 as a continuous pipe results in less contamination during use, while at the same time providing optimized cleaning by directing the irrigation fluid towards the target. A small portion of the irrigation fluid still passes through the tool opening 40 as the distal outlet opening of the instrument handpiece 1, again providing optimal cleaning since there are no components obstructing the flow of the irrigation fluid. Figures 6a and 6b show structural details regarding the installation or mounting of the bearing cage 50. The bearing cage 50 can be seen in more detail as a separate component in Figure 7.

[0102] The technical effect on the path of the flow lines S, which is brought about not only by the structural design but also by the arrangement of the particularly preferred embodiment with the bearing cage 50, can be seen, in particular, by referring again to Figure 6b. It can be seen that the bearing cage 50 also causes a forced throughflow through the distal needle bearing 20, i.e., said needle bearing 20 is in any case passed through and therefore cleaned. In particular, in addition, a large degree of independence of the cleaning fluid from the proximally applied input pressure is preferably obtained by the installation of such a bearing cage 50, which further promotes the stability of the cleaning method according to the present disclosure.

[0103] FIG. 7 shows a slightly perspective side view of the bearing cage 50 in the form of an enlarged, excerpted representation with reference to FIGS. 6a and 6b. The bearing cage 50 may be provided inside an instrument handpiece 1 according to the present disclosure, preferably as a separate component of a roller bearing arrangement for a tool. From the view of FIG. 7, it is clear that the bearing cage 50, in the form of a cylindrical pipe, spaces apart the distal roller bearing 20 (located on the left side of the figure) and the proximal roller bearing 22 (located on the right side of the figure). The distal roller bearing 20 and the proximal roller bearing 22 are thereby realized by five needles 30, respectively. The needles are non-spherical rolling elements evenly distributed around the periphery of the bearing cage 50. The needles 30 are arranged to be rotatable / rollable about their longitudinal axes within corresponding longitudinal grooves 35 of the bearing cage 50. Also visible at the proximal end of the bearing cage 50 are a plurality of spherical guide elements 60 and sliding surfaces 61.

[0104] FIG. 9 shows a cross-sectional view of an instrument handpiece 1 according to the present disclosure, illustrating the region at the transition 12 to the handle portion 7 (according to FIG. 4 ). This region is proximal to the shaft portion 8. For the throughflow (shown by the dotted exiting streamline S), the (cylindrical) ring gap cross-sectional area AR (e.g., approximately 3.6 mm ) belonging to the cross-section of FIG. 9 is 2 ) is formed between a corresponding outer cylindrical ring gap outer diameter d-R1 (e.g., about 3.2 mm) and a corresponding inner ring gap inner diameter d-R2 (e.g., about 2.4 mm).

[0105] 10a and 10b (similar to FIGS. 8a and 8b relating to the prior art) show first and second cross-sectional views of the instrument handpiece 1 (without a tool) of the present disclosure in the preferred embodiment according to FIGS. 4 to 7. First, FIG. 10a shows a first cross-sectional view of a region of the tool receiving portion 19 in the shaft portion 8 having the second diameter D2. This region is proximal to the proximal roller bearing 22 (according to FIG. 6a).

[0106] 10b also shows a second cross-sectional view of the central region of the bearing cage 50 (according to FIGS. 6a and 7) at the constricted distal tip 10 according to the present disclosure having a first diameter D1, this second cross-sectional view being more distal than the first cross-sectional view of FIG. 10a.

[0107] Analogous to the above description of the prior art (based on Figures 8a and 8b, which describe the prior art), the first and second cross-sectional views of Figures 10a and 10b make particular reference to the fluid dynamics diagram in Figure 6b, which uses a straight streamline S (or in fact two streamlines selected as an example from among several) to show the state of the instrument handpiece 1 as the flow passes through it.

[0108] From FIG. 10a, for the throughflow (shown by the dotted exiting streamline S), the (cylindrical) ring gap cross-sectional area AR (e.g., about 3.6 mm ) belonging to the cross section of the shaft portion 8 in FIG. 2 ) is formed between a corresponding outer cylindrical ring gap outer diameter d-R1 (eg, about 4.5 mm) and a corresponding inner ring gap inner diameter d-R2 (eg, about 4.0 mm).

[0109] It may therefore be particularly preferred that the ring gap cross-sectional area AR belonging to the cross section of the shaft portion 8 in Figure 10a approximately corresponds to the (cylindrical) ring gap cross-sectional area AR belonging to the cross section of Figure 9 (area relationship to each other of 90% to 110%, more preferably 98% to 102%, in particular about 100%). This has the advantage that the rinse pressure, flow rate or kinetic energy in the instrument handpiece 1 is uniform in its path from proximal to distal.

[0110] 10b for the distal cross section according to the present disclosure, with reference to FIGS. 6a and 6b, it can be inferred that the constricted distal tip 10 having a first diameter D1 comprises a cylindrical continuous bearing cage 50 spaced therein (in the longitudinal direction of the instrument handpiece 1). For throughflow (indicated by the dotted outflow streamline S), a corresponding ring gap is formed around the bearing cage 50. Meanwhile, at least the proximal end, and preferably also the distal end, of the bearing cage 50 is blocked so that the central cylindrical volume of the bearing cage 50 cannot / is not exposed to the throughflow.

[0111] In the direction of view, behind the cross section of the distal tip 10 as shown in Figure 10b through the central region (in the longitudinal direction) of the bearing cage 50, five needles 30 can be recognized as non-spherical rolling elements (see Figure 7). The needles 30 are uniformly distributed around the circumference of the bearing cage 50.

[0112] As a result, a corresponding ring gap in the inner surface portion 33 is formed on the outer surface of the continuously formed bearing cage 50 between the inner surface portion diameter d-33 (e.g., about 3.8 mm) as the ring gap outer diameter and the bearing cage outer diameter d-50 (e.g., about 3.3 mm) as the ring gap inner diameter. Here, the ring gap arranged around the bearing cage 50 has a bearing cage ring gap cross-sectional area A-50 (e.g., about 2.8 mm 2 )

[0113] Preferably, the ring gap cross-sectional area A-50 of the bearing cage is 3.5 mm 2 and more preferably about 3 mm or less. 2 It is particularly preferably 2.8 mm or less. 2Alternatively or additionally, the bearing cage ring gap cross-sectional area A-50 may be equal to or less than the free flow cross-sectional area in a region of the instrument handpiece 1 proximal thereto, as shown, for example, in Figures 10a and / or 9. More preferably, the bearing cage ring gap cross-sectional area A-50 may be equal to or less than the proximal shaft ring gap cross-sectional area AR (see Figure 9).

[0114] In particular, the present disclosure allows for the proactive increase of the rinse pressure applied or present at the distal outlet opening (reference numeral 40, see FIGS. 4-6a) or the rinse pressure applied or present in the proximal-to-distal flow direction at the bearing cage ring gap cross-sectional area A-50. As a result, the instrument handpiece according to the present disclosure provides a remedy for a technical problematic situation in the prior art, which can arise in the form of individual rinse pressures that can be too low, particularly in situations with high hospital utilization rates. As an example, in a cleaning and disinfection unit (not shown) (e.g., a MIELE G 7825 structure 80) as a rinse device, the total proximal input pressure of the cleaning fluid supplied from an external source to several connected instrument handpieces to be cleaned can be up to approximately 1600 mbar in absolute proximal pressure. Considering a pressure differential / excess pressure / pressure delta relative to atmospheric pressure of, for example, approximately 950 mbar, this results in a maximum (proximal) rinse pressure of approximately 650 mbar for each connected instrument handpiece 1. However, if several instrument handpieces are present or connected, the maximum (proximal) rinse pressure is divided among the several handpieces and reduced to their respective rinse pressures. An exemplary cleaning and disinfection unit provides up to 22 connections ("Luer Lock: Type Miele", connection inner diameter 3 mm; therefore, flow cross section: A = approx. 7 mm). 2). When 11, i.e. half, of the instrument handpieces were connected, a proximal drop in the respective (proximal) rinse pressure to about 500 mbar could be observed. When 22 (out of 22) instrument handpieces were connected, it could be observed that the respective (proximal) rinse pressure was reduced proximally or even reduced to about 315 mbar. Thus, the respective (proximal) rinse pressure was available at the inlet of the instrument handpiece (e.g. φ1.7 mm, A=2.27 mm). 2 (Flow cross section at the proximal handle of the pump).

[0115] The (proximal) rinse pressure applied proximally of the exemplary cleaning and disinfection unit is reduced from proximally to distally present (distal) rinse pressure, further taking into account various flow resistances such as pipe friction along the internal flow through the instrument handpiece.

[0116] The present disclosure ensures reliable and adequate fluid flushing even when the respective rinsing pressures are low. The constricted distal tip 10 ensures that effective rinsing pressures still exist in the distal region. In particular, the particularly preferred embodiment with the continuously formed bearing cage 50 allows a strong forced throughflow in the bearing cage ring gap cross-sectional area A-50 surrounding the bearing cage. Therefore, effective fluid flushing occurs downstream / distal to the non-constricted shaft section 8, i.e., even in the distal tip 10, despite losses in fluid pressure. This fluid flushing ensures undiminished mechanical flushing capabilities in the distal roller bearing 20 and in the proximal roller bearing 22. Insofar, even the proximal roller bearing 22 receives the entire rinsing flow of flushing fluid. [Explanation of symbols]

[0117] 1 Instrument Handpiece 5 Connection 7 Handle 8 Shaft section 10 Distal tip 11 Transition Zone 12 Surface shape section 19 Tool holder 20 Distal Roller Bearing 22 Proximal Roller Bearing 24 outer ring 26 Inner ring 30 rolling elements 32 Guide bush 33 Inner surface part 35 longitudinal groove 40 distal exit opening 50 bearing cage 60 Guide Elements 61 Sliding surface A Exit cross-sectional area AB bore cross-sectional area AR ring gap cross-sectional area A-22 Roller bearing space cross-sectional area A-50 Bearing Cage Ring Gap Cross Section Area D1 First diameter (at the distal tip) D2 Second diameter (of the shaft) dB Bore diameter d-24 Outer ring diameter (inner) d-26 Inner ring diameter (outside) d-33 Inner surface diameter d-50 Bearing cage outer diameter d-R1 Ring gap outer diameter d-R2 Ring gap inner diameter L1 First length (distal tip) L2 Second length (overall shaft section) S (cleaning fluid) streamline S

Claims

1. A surgical instrument handpiece (1) for a surgical instrument, comprising: a handle portion (7) that is proximally manipulated by an operator; a shaft portion (8) extending longitudinally distally from the handle portion (7); It is equipped with a distal exit opening (40) at the distal end of the shaft portion (8) opposite the handle portion (7) into which a tool is placed or which can be placed by a user; A surgical instrument handpiece (1), characterized in that the shaft portion (8) has at least one narrowed distal tip (10) with a reduced cross-sectional area in the region of the distal outlet opening (40).

2. the first diameter (D1) of the constricted distal tip portion (10) is smaller than the second diameter (D2) of the non-constricted region of the shaft portion (8) by a diameter relationship factor of at most 95 percent, preferably at most 85 percent, and more preferably at most about 79 percent; and / or The surgical instrument handpiece (1) according to claim 1, wherein said first diameter (D1) is between 3.5 and 5.3 mm, preferably between 4.0 and 5.0 mm, and more preferably between 4.3 and 4.5 mm.

3. the first length (L1) of the distal tip portion (10) is at least 5 percent, preferably at least 20 percent, and more preferably at least 35 percent of the total second length (L2) of the shaft portion (8); and / or A surgical instrument handpiece (1) according to claim 1 or 2, wherein said first length (L1) is between 5 and 40 mm, preferably between 10 and 30 mm, and more preferably between 18 and 22 mm.

4. 4. The surgical instrument handpiece (1) according to claim 1, wherein a transition area (11) designed as a shoulder from the constricted distal tip (10) of the shaft portion (8) to the non-constricted region (11) is rounded and / or tapered and / or chamfered.

5. The surgical instrument handpiece (1) is adapted to be inserted into a rinsing device, such as a cleaning and sterilization unit; When flushing the interior of the surgical instrument handpiece (1) with a flushing fluid, preferably a hydrophilic or lipophilic flushing fluid, in a proximal to distal flow direction, the rinse pressure present at the distal outlet opening (40) is greater than 10 mbar, more preferably greater than 90 mbar, more preferably greater than 160 mbar, in particular greater than 500 mbar; and / or 5. A surgical instrument handpiece (1) according to any one of claims 1 to 4, wherein the rinse pressure present at the distal outlet opening (40) is maintained at a ratio of at least 20 percent, preferably at least 50 percent, and more preferably at least 80 percent of the proximally applied input pressure of the irrigation fluid.

6. the shaft portion (8) preferably comprises, at least in part in the region of the narrowed distal tip (10), an internal roller bearing arrangement for rotatably mounting the positioned or positionable tool; the roller bearing arrangement comprises at least one distal roller bearing (20) and at least one proximal roller bearing (22); 6. A surgical instrument handpiece (1) according to any one of claims 1 to 5, wherein the at least one distal roller bearing (20) and the at least one proximal roller bearing (22) are spaced apart by a bearing cage (50) formed continuously therebetween.

7. The surgical instrument handpiece (1) is adapted to be inserted into a rinsing device, such as a cleaning and sterilization unit; 7. The surgical instrument handpiece (1) according to claim 6, wherein when the interior of the surgical instrument handpiece (1) is vigorously irrigated with an irrigation fluid, preferably a hydrophilic or lipophilic irrigation liquid, in a proximal to distal flow direction, a rinsing pressure present at the distal outlet opening (40) is greater than 600 mbar, preferably greater than 700 mbar, more preferably about 800 mbar.

8. The bearing cage (50) is either completely closed or permeable to fluids at a small area-related pore volume fraction; 8. A surgical instrument handpiece (1) according to claim 6 or 7, wherein the pore volume fraction is preferably less than 40 percent, more preferably less than 15 percent, and particularly preferably less than 8 percent.

9. 9. A surgical instrument handpiece (1) according to any one of claims 6 to 8, wherein the at least one distal roller bearing (20) and / or the at least one proximal roller bearing (22), preferably all roller bearings of the internal roller bearing arrangement, are provided with non-spherical rolling elements and are preferably formed as cylindrical roller bearings and / or needle bearings.

10. 10. A surgical instrument handpiece (1) according to any one of claims 6 to 9, wherein the at least one distal roller bearing (20) and / or the at least one proximal roller bearing (22), preferably all roller bearings of the internal roller bearing arrangement, are equipped with ceramic rolling elements.

11. On the outer surface of the continuously formed bearing cage (50), a ring gap is formed between the inner surface portion diameter (d-33) of the inner surface portion (33) as the ring gap outer diameter and the bearing cage outer diameter (d-50) as the ring gap inner diameter, The bearing cage ring gap cross-sectional area (A-50) of the ring gap located at the narrowed distal tip (10) is 3.5 mm ２ More preferably, it is about 3 mm or less. ２ It is particularly preferably 2.8 mm or less. ２ and / or 11. The surgical instrument handpiece (1) according to any one of claims 6 to 10, wherein the bearing cage ring gap cross-sectional area (A-50) is equal to or less than the free-throughflow cross-sectional area in the region of the surgical instrument handpiece (1) proximal thereto, and preferably equal to or less than the proximal shaft ring gap cross-sectional area (A-R) of the shaft portion (8).

12. A surgical instrument handpiece (1) according to any one of claims 1 to 11, a tool that is preferably driven in rotation and / or can be driven in rotation, A surgical instrument having:

13. A medical product set comprising: Preferably, the assortment is tailored to an operator, such as a surgeon; At least one first surgical instrument handpiece (1) according to any one of the preceding claims 1 to 12, comprising at least A surgical instrument according to claim 12 and / or a plurality of medical tools, and / or A second surgical instrument handpiece (1) according to any one of claims 1 to 12 associated with said surgical instrument handpiece (1), and / or a tool wrench for inserting a corresponding tool into said surgical instrument handpiece (1); It has a combination of said plurality of medical tools are in particular rotationally driven and / or rotationally drivable medical tools, preferably an assortment of tools of different functions and types, and / or of straight and / or curved shapes, and / or of different sizes and / or hardness and / or materials, The first surgical instrument handpiece (1) and the second surgical instrument handpiece (1) have different first diameters (D1) and / or different second diameters (D2) and / or different first lengths (L1) and / or different second lengths (L2). Medical products set.

14. Associated with said surgical instrument handpiece (1) is a rinsing device, such as a cleaning and disinfecting unit, adapted to vigorously clean the interior of the surgical instrument handpiece (1) according to the invention of any one of claims 1 to 13.

15. A cleaning method for a surgical instrument handpiece (1) according to any one of the preceding claims 1 to 14, which is associated with the surgical instrument handpiece (1), comprising vigorously cleaning the interior of the surgical instrument handpiece (1) in a proximal to distal flow direction in a rinsing device according to claim 14.

16. A cleaning method for a surgical instrument handpiece (1) according to claims 6 to 11, comprising:

16. The cleaning method according to claim 15, characterized in that the flow lines of the cleaning fluid preferably flowing through the proximal roller bearing (22) include flow lines along the outer surface of the bearing cage (50) formed continuously and / or through the at least one distal roller bearing (20).

Images