SURGICAL INSTRUMENT HANDLE

Abstract

The invention relates to a surgical instrument handpiece (1) for a surgical instrument, an associated surgical instrument, an associated medical product set having the surgical instrument handpiece (1) in combination with at least one accessory, an associated rinsing device, as well as an associated cleaning method for the internal flushing of the surgical instrument handpiece (1). The surgical instrument handpiece (1) comprises a handle section (7) for proximal handling by an operator and a shaft section (8) which extends from the handle section (7) in a distal longitudinal direction, wherein a tool is or can be arranged by a user in a distal outlet opening (40) of the shaft section at the distal end opposite the handle section (7), characterised in that the shaft section (8) has at least one distal tip section (10) with a reduced cross-sectional area in the region of the distal outlet opening (40).

Description

[0001] Surgical instrument handpiece

[0002] Description

[0003] Technical field

[0004] The present disclosure relates to a surgical instrument handpiece used to hold or drive a surgical tool in the broadest sense, in particular a rotatable tool such as a milling cutter, drill, grinding head, or the like. Furthermore, the present disclosure relates to such a surgical instrument and an associated medical product set comprising the surgical instrument handpiece in combination with at least one accessory. Additionally, an associated rinsing device, such as a cleaning and disinfection unit or a thermal disinfector, and an associated cleaning method for internally rinsing the surgical instrument handpiece are proposed.

[0005] In the prior art of modern minimally invasive surgery, particularly neurosurgery and spinal surgery, it is known to use surgical instrument handpieces for the purpose of working on, for example, bones, cartilage, vertebrae, etc. German patent application DE 102013 111 194 A1 of the present applicant, which is hereby expressly incorporated into the present application by reference, relates to a generic surgical instrument handpiece. The respective surgical instrument handpiece typically has at least one receptacle or coupling for a connectable, preferably rotatably driven, tool. Medical indications for the use of surgical instrument handpieces include arthroscopy for the examination and / or treatment of joints, orthopedic procedures, spinal surgery, maxillofacial surgery, neurosurgery, etc.During the use of surgical instruments (or instrument handpieces), the distal end of the instrument (or instrument handpiece) comes into contact with organic and inorganic substances, such as body fluids and bone debris, which tend to accumulate on and / or in the instrument (or instrument handpiece) in the form of deposits or build-up. Therefore, the use of reusable surgical instruments (or instrument handpieces) requires proper reprocessing before and / or after each use, in particular cleaning and / or disinfection, to remove the contaminants adhering to the instrument and ensure its sterile reuse.

[0006] Cleaning the lumen or hollow body of the instrument handpiece, including its internal surfaces and / or parts, presents a particular challenge. For this purpose, the instrument handpiece or its hollow body is rinsed with a cleaning fluid, especially a cleaning solution. This internal rinsing with the cleaning fluid is intended to loosen and remove dirt particles that have accumulated on the internal surfaces and / or parts of the hollow body or instrument handpiece.

[0007] Cleaning the spaces within the hollow body of the instrument handpiece, especially its distal (patient-facing) ball bearings for holding a rotatable tool such as a milling cutter or drill, has proven particularly difficult. Due to the low resistance, the cleaning fluid flows almost exclusively through the inner rings or along the inner surfaces of the distal ball bearings as it passes through the instrument handpiece, meaning that the balls, cages, and spaces within these bearings are not adequately cleaned.

[0008] This problem is already addressed in the prior art. For example, the patent application of the present applicant, with the officially assigned file number DE 102018 133503.2, the disclosure of which is hereby expressly incorporated into the present application by reference, discloses a separate rinsing device with or consisting of a shaft-like rinsing insert for the internal cleaning of an instrument handle of a surgical instrument, in particular a rinsing device for cleaning the distal ball bearings in the interior of an instrument handle. The rinsing device proposed therein is inserted or attached to a tool holder or tool holder shaft of the instrument handle after its surgical use for the purpose of cleaning.

[0009] While the prior art solution described above is convincing with regard to the achievable cleaning efficiency, it still has the disadvantage that, with the disclosed rinsing device, a separate device—namely, the shaft-like rinsing insert—must be kept in the Central Sterile Supply Department (CSSD), Central Sterilization Unit (CSSD), or Medical Device Reprocessing Unit (MDRU) in addition to the instrument handle and inserted into the instrument handle before the cleaning cycle. There is a risk that the separate rinsing device could be lost. Furthermore, the handling and application of the rinsing device must be described and implemented separately.

[0010] Furthermore, independent of the cleaning aspect discussed above, there are other disadvantages to the current state of the art regarding surgical instrument handpieces with respect to their medical, and especially surgical, application. These disadvantages arise from the perspective of the external dimensions and the light-gathering dimensions of the shaft section. For minimally invasive, low-trauma procedures, there is a need for surgical instrument handpieces that are as small as possible, or even smaller. One disadvantage of the current state of the art, particularly when visualizing the surgical procedure or handling the instrument in real time within the patient, especially via an endoscopic camera image displayed on an operating room monitor for the surgeon, is that their size obstructs or shadows the view of the tissue.This visual obstruction is particularly pronounced and therefore more detrimental in the field of microsurgery. Furthermore, with regard to surgical access, for example in brain surgery, or the operable indications themselves, there is a need for smaller surgical instrument handpieces or a corresponding expansion of the surgical application range.

[0011] US 2017 / 0120451 A1 discloses a surgical instrument handpiece in the form of an assembly for holding a tool, wherein the arrangement can selectively reduce and / or eliminate vibrations that are received and felt by a user. By reducing vibrations, chatter at the working end of a tool can be reduced or eliminated. For this purpose, a vibration-damping intermediate piece is arranged between a shaft section for tool retention and a handle section of the surgical instrument handpiece. Two slightly different inner diameters are disclosed in the transition region of the intermediate piece, but in a section located proximal to a ball bearing, thus relating to the proximal shaft section within the handle section.Furthermore, a potential problem in the prior art is that the total inlet pressure of the cleaning fluid (in the sense of a pressure difference or pressure excess compared to atmospheric pressure) applied externally to a number of connected instrument handpieces in a rinsing device such as a washer-disinfector is distributed proportionally to the number of instrument handpieces, thus reducing the individual rinsing pressure. Consequently, if the rinsing device is overloaded, the situation may arise where the individual rinsing pressure falls below the minimum value required for reliable and sufficient fluid cleaning. This technical disadvantage of a potentially insufficient individual rinsing pressure can occur particularly in situations with high clinical utilization.

[0012] Furthermore, in the prior art, the disadvantageous situation may exist that the free flow cross-section (or internal empty volume) of the instrument handpiece available for the flow of cleaning fluid widens along the longitudinal direction or flow direction from proximal to distal. Consequently, the mechanical cleaning effect deteriorates from proximal to distal, in addition to the general flow pressure losses, particularly due to tube friction and other flow resistance coefficients.

[0013] The invention therefore aims to create a surgical instrument handpiece for a surgical instrument that overcomes the disadvantages of the prior art outlined above. First, it aims to provide an even more reliable instrument handpiece that can be cleaned or sterilized (alternatively) by means of internal rinsing. In particular, the design of the instrument handpiece should enable targeted and powerful cleaning of the distal ball bearings. Furthermore, an additional objective is to provide the user with a wider range of surgical indications. Finally, a further objective is to simplify the processes in the Central Sterile Supply Department (CSSD), making them more cost-effective and less prone to errors.

[0014] These problems are solved, as disclosed, by the features of claim 1.

[0015] The surgical instrument handpiece for a surgical instrument, as a first aspect of the present disclosure, comprises a handle section for proximal handling by a surgeon and a shaft section extending distally from the handle section. A tool is arranged at the distal end of the shaft section, opposite the handle section, in a distal exit opening, or can be arranged by a user such as the surgeon or a surgical assistant. For the purposes of this disclosure, a tool is understood to be any device or unit with which a surgeon can treat and / or manipulate the body or body parts of a patient, or implants, or the like, wherein the tool is guided by the surgeon via the instrument handpiece.

[0016] According to the disclosure, the shaft section in the region of the distal outlet opening has at least one constricted distal tip section. The term "constricted" or "narrowing" refers to a cross-sectional area at the distal end, in particular to a clear outer dimension of the shaft section, and preferably also to an inner flow cross-section.

[0017] In the context of this disclosure, the term "distal" refers to the application-related perspective of the operator or user handling the instrument handpiece as described above, which corresponds to the patient-facing side. Accordingly, the term "proximal" refers to the side facing the operator or user, i.e., the side away from the patient.

[0018] Thus, as revealed, the shaft section is subdivided along its longitudinal direction into at least two (longitudinal) sections, a first section and a second section, with different cross-sectional areas. The encompassed first section, with its smaller first cross-sectional area, is referred to as the narrowed distal tip section of the (entire) shaft section. The encompassed second section, with its larger second cross-sectional area compared to the first section, is referred to as the unconstricted section of the (entire) shaft section. In other words, the narrowed first section, or the distal tip section, adjoins the shaft section, which extends distally from the handle section, or the unconstricted second section of the (entire) shaft section, in the distal longitudinal direction. That is to say, a first length along which the first section extends...The distal tip section, which extends in the form of a constriction, corresponds to a portion of the total length of the (entire) shaft section, referred to as the second length. Therefore, the difference between the (entire) second length and the first length refers to the (remaining) second section, or the unconstricted portion of the shaft section.

[0019] According to the disclosure, the flow velocity of the cleaning fluid, and thus the hydrodynamic cleaning effect, is increased due to the distal narrowing of the flow cross-section. Due to the design of the instrument handpiece according to the disclosure, during internal rinsing, the cleaning fluid is directed in a specific flow direction from proximal to distal, all the way to the distal outlet opening. This prevents the fluid from flowing through the comparatively large opening of an inner ring of a distal ball bearing, which offers very little flow resistance in the prior art, in a less effective or ineffective manner. In other words, the present disclosure serves to reduce the proportion of the cleaning fluid flow that is not effectively directed or is even misdirected. This is achieved while largely maintaining a flow rate that is sufficient for the cleaning effect, ideally even exceeding the required level.

[0020] The flow pressure is caused by the main flow direction along the longitudinal axis of the instrument handpiece.

[0021] Furthermore, the optimized outer contour of the shaft section, which is narrowed in the distal tip section, advantageously improves the surgeon's visual access during a procedure.

[0022] In addition, the disclosure supports simplified processes in the Central Sterile Supply Department (CSSD), which has a positive impact on both reduced operating costs and improved quality assurance and reliability. The disclosed novel design of the distal tip, or the tip section encompassed by the shaft section, of the instrument handpiece increases the cleaning effect, particularly with regard to the distal ball bearings and / or an inner surface section of the (distal) tip section, during manual or automated cleaning, without the need for additional products such as a special rinsing device.

[0023] For the purposes of the disclosure, it is not relevant whether, in addition to the at least one narrowed distal tip section, further sections with a different cross-sectional area are included by the shaft section, in particular by the first section or the distal tip section itself. In other words, it is conceivable that further circumferential shaft shoulders and / or shaft steps are formed. Furthermore, for the purposes of the disclosure, it is not relevant what type of connection or interface of the instrument handpiece for external power supply, handling, or driving of the preferably rotatably driven tool is designed, preferably located at the proximal end of the handle section. Depending on the intended use and the intended tool speed, a hydraulic, pneumatic, and / or electric motor drive can be provided or operatively connected.

[0024] Furthermore, it is not relevant for the purposes of the disclosure that the constriction or the constricted cross-sectional area has a specific shape. These terms are therefore not to be understood as limited to elongated shapes with a constant round cross-section, such that radially circumferential shoulders and / or radial steps are formed. Rather, the present terminology also encompasses any constrictions with a cross-section that varies along its longitudinal axis and / or with a cross-section that has a non-round shape, e.g., an oval, rectangular, convex, and / or concave shape. In particular, the constriction may only be formed in an angular segment or may form an asymmetrically constricted cross-sectional area.

[0025] The dependent claims describe preferred embodiments of the invention.

[0026] However, for production-related reasons as well as from application-related, especially fluid dynamic, points of view, radially constant or round cross-sectional areas or constrictions of the shaft section may often be preferred.

[0027] Therefore, from the aforementioned perspectives, it is preferred that the surgical instrument handpiece is further developed such that a first diameter of the narrowed distal tip section is smaller than a second diameter of an unnarrowed section of the shaft by a diameter ratio factor of at most 95 percent, preferably at most 85 percent, and more preferably by approximately 79 percent. Alternatively or cumulatively, the first diameter is preferably between 3.5 and 5.3 millimeters, preferably between 4.0 and 5.0 millimeters, and more preferably between 4.3 and 4.5 millimeters.

[0028] In particular, a change in diameter or narrowing can preferably be provided from the second diameter, such as an outer diameter of the shaft section of approximately 5.6 mm, especially with regard to an area adjacent to the handle section, down to approximately 4.4 mm for the first diameter, such as an outer diameter of the narrowed distal tip section.

[0029] Preferably, the surgical instrument handpiece is further developed such that a first length of the distal tip section is between 5 and 40 millimeters, preferably between 10 and 30 millimeters, and more preferably between 18 and 22 millimeters.

[0030] Alternatively or cumulatively, the first length preferably measures, insofar as it is related to, or compared to, a total second length of the shaft section, or normalized, a percentage length of at least 5 percent, preferably at least 20 percent, and more preferably at least 35 percent.

[0031] In particular, an instrument handpiece may be preferred in which the distal tip section, preferably approximately 4.4 mm wide, extends to approximately 20 mm as the first length, while the second (total) length is selected or set according to an application-technical or surgically optimal length for the (total) shaft section, preferably approximately 5.6 mm wide.

[0032] Experimental testing using exemplary prototypes has shown that such particularly preferred embodiments of the disclosure represent a further optimized balance of all application-related dimensions and independent groups of technical problems and tasks. Specifically, the aforementioned surgical aspects constitute a first group of technical tasks, while the fluid dynamic effects for the purpose of subsequent cleaning constitute a second group. The first group relates to an initial application period during surgical use, particularly by a surgeon as the first user; and the second group relates to a second application period after surgical use, particularly by personnel involved in the cleaning and sterilization of surgical instruments as the second user.

[0033] However, it is understood that the disclosure is not limited to the aforementioned particularly preferred embodiments. Particularly in the case of miniaturization – as is known from the scientific principles of the key figures problem in fluid dynamics – different or alternative absolute and / or relative dimensions must be chosen or are preferred.

[0034] Preferably, the transition area formed as a step from the narrowed distal tip section to the unnarrowed area of ​​the shaft section is rounded and / or gradually tapered and / or beveled. Avoiding such an angular or abrupt transition between the first and second sections offers the advantage of reduced dirt adhesion and less tissue trauma during surgical handling or insertion into tissue opened by the surgeon.

[0035] Preferably, the surgical instrument handpiece is designed to be inserted into a rinsing device, such as a washer-disinfector, such that the rinsing pressure is optimized. This pressure is applied when the instrument handpiece is internally rinsed with a cleaning fluid, preferably a hydrophilic or lipophilic cleaning solution, in the flow direction from proximal to distal at the distal outlet. 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 particularly greater than 500 mbar. Alternatively or cumulatively, the rinsing pressure, insofar as it is referenced to or normalized to a proximally applied inlet pressure of the cleaning fluid, is maintained to a proportion of at least 20 percent, preferably at least 50 percent, and more preferably at least 80 percent.In this way, a particularly high cleaning effect can be achieved, as can be demonstrated in particular by standardized cleaning test values, as used in the complex expertise and legal guidelines for the reprocessing of medical devices.

[0036] This is particularly advantageous in effectively counteracting the problem, encountered in the prior art, of a reduction in irrigation pressure or flow pressure, sometimes significantly, along the longitudinal direction of the instrument handpiece from proximal to distal or along the flow direction (or along the direction of the streamlines). This problem can be particularly serious with conventional instrument handpieces if, or insofar as, the (internal) flow cross-sectional area is not only not constant but even increases, and especially increases significantly, along the longitudinal direction of the instrument handpiece from proximal to distal or along the flow direction. The continuity equation for the (incompressible) flow states A·n = V = const.; where A is the (internal) flow cross-sectional area; v is an (averaged)

[0037] The flow velocity of the cleaning fluid; and V denotes an (internal) volumetric flow rate of the cleaning fluid. According to the continuity equation for (incompressible) flow, this results in a corresponding decrease in the flow velocity (which is negatively correlated with the flow cross-sectional area). Consequently, the flow term for the kinetic energy decreases (cf. Bernoulli's equation), which also leads to an unfavorable reduction in the mechanical cleaning effect in the prior art.

[0038] Preferably, a Reynolds number (Re) can define a turbulent region for the flow through the constricted distal tip section, particularly above Re = 2300. The Reynolds number is defined as the density and dynamic viscosity of the fluid, using the properties of the cleaning fluid, especially water. The (averaged) flow velocity of the cleaning fluid (v) is used as the flow velocity. Here, a characteristic length of the body (or tube), also called the reference length, is preferably defined as the diameter of a cross-sectional area available to the flow, and more preferably as the diameter of the inner surface section of the (distal) tip section. A turbulent region can offer advantages in terms of particularly powerful cleaning, especially in the case of stubborn dirt or contaminants.

[0039] As an alternative to a Reynolds number indicating a turbulent region in the narrowed distal tip section, it may be particularly preferred that the Reynolds number indicates a laminar region in the narrowed distal tip section. Particularly preferably, Re may be between 1000 and 2000. This has the advantage of a uniform flow through the instrument handpiece according to the disclosure, avoiding pulsation and / or fluid-wall interactions. This enables a particularly uniform, quiet, and low-vibration cleaning operation of an irrigation device.

[0040] Preferably, the shaft section comprises an internal rolling bearing for the rotatable mounting of the arranged or arrangeable tool, preferably at least partially in the region of the narrowed distal tip section. The rolling bearing comprises at least one distal rolling bearing and at least one proximal rolling bearing. Furthermore, the at least one distal rolling bearing and the at least one proximal rolling bearing are spaced apart by a bearing cage extending continuously between them.

[0041] As a result, the adverse flow behavior described in the prior art is avoided, which exhibits a flow maximum along a cylinder axis of the shaft section or at the center of the second cross-sectional area. This adverse flow behavior in the prior art arises from the flow law of the path of least resistance and / or from the flow condition known as the wall adhesion condition, particularly in the case of pipe flow, and / or also from the consideration of the interior of a rolling bearing according to the flow through a packed bed ("Pre-Darcy"). In other words, the prior art results in an adverse hydrodynamic distribution of the flow velocity (or the vector component in the longitudinal direction of the instrument handpiece from proximal to distal) with a maximum at the center of the shaft section.along a rotational axis of the instrument handpiece.

[0042] In particular, the total length of the continuous bearing cage can be at least 90% of the first length of the distal tip section. Alternatively or cumulatively, the distance length associated with the continuous bearing cage between the at least one proximal rolling bearing, e.g. (but not limiting) from its centerline, and the at least one distal rolling bearing, e.g. (but not limiting) from its centerline, can be at least 60%, more preferably at least 70%, and in particular at least 78% of the first length.

[0043] The particularly preferred embodiment of the present disclosure relating to a continuously formed bearing cage overcomes the aforementioned disadvantage of the prior art in a particularly effective manner. In this respect, a forced flow through the inner rolling bearing and / or along the inner surface section is achieved. Thus, the mechanical cleaning effect by means of the cleaning fluid is further intensified in the state connected to the rinsing device, in particular to the cleaning and disinfection unit. As a result, reliable and thorough fluid cleaning takes place precisely at the points or surfaces where contaminants can adhere, and this is also effective. In other words, the efficiency of the fluid cleaning or rinsing is increased by preventing the cleaning fluid from seeking the path of least (flow) resistance and escaping in the center.Instead, according to the disclosure, the cleaning fluid is directed specifically towards the surfaces to be cleaned, where it is intended to exert its mechanical cleaning effect, namely in particular within the at least one distal rolling bearing and at least one proximal rolling bearing and / or along the inner surface section of the narrowed distal tip section.

[0044] In the present context, rolling bearings are defined as bearings in which, unlike the lubrication in plain bearings, rolling elements such as balls, cylinders, needles, barrels or cones reduce frictional resistance between an inner ring and an outer ring.

[0045] In the embodiment with the internal rolling bearing, preferably with the continuously formed bearing cage, a targeted flow guidance or a forced flow of the cleaning fluid is additionally effected through a gap empty volume, which is created or formed between an inner surface section of the (distal) tip section and a bearing cage outer surface section.

[0046] Furthermore, a situation may be preferred, in contrast to the prior art, in which (almost) all other possible flow paths of the instrument handpiece (with the exception of the gap void volume) such as an internal bore are closed by at least one complementary component such as a drive shaft. In other words, the forced flow takes place exclusively (or completely) through the gap void volume.

[0047] In particular, the gap void volume can refer to an annular gap void volume. In this respect, the inner surface section of the (distal) tip section and the outer surface section of the bearing cage can preferably be cylindrical, and more preferably arranged concentrically, i.e., on a coincident central axis. For the purposes of this disclosure, it is irrelevant whether or to what extent tolerances or fits, particularly those related to manufacturing, are present. In particular, the latter can be arranged alternatively or cumulatively to consider a design or construction criterion and / or an operating criterion, preferably a concentricity characteristic of the inner rolling bearing and / or a machine dynamic parameter.

[0048] Each annular gap volume corresponds to a specific flow cross-sectional area. A cylindrical annular gap cross-sectional area is formed between an outer annular gap diameter (of a cylindrical internal component, particularly the continuous bearing cage) and an inner annular gap diameter for forced flow. Thus, the annular gap cross-sectional area is calculated as the flow cross-sectional area by subtracting the areas of the two circular surfaces with the outer and inner diameters of the annular gap, respectively.

[0049] Particularly preferably, the (respective flow) cross-sectional area, especially the annular gap cross-sectional area, does not increase in the flow direction of the cleaning fluid or along the second length of the entire shaft section (from proximal to distal), particularly from a proximal area at the transition to the handle section to a distal area at the proximal rolling bearing and / or to the outlet cross-sectional area. In other words, the annular gap cross-sectional area, in particular, can remain constant and / or narrow in the flow direction. It is further preferred that the narrowing is continuous and / or has no discontinuities. This serves to avoid abrupt changes in the flow state. In particular, this avoids local dead zones, turbulence, or throttling effects, which can lead to local deteriorations in the mechanical fluid cleaning.

[0050] In the preferred embodiment with the internal rolling bearing in the manner of the continuously formed bearing cage, the bearing cage annular gap cross-sectional area formed around the outer circumference of the (central) bearing cage results from the subtraction of the two circular areas with the inner surface section diameter as the annular gap outer diameter or with the bearing cage outer diameter as the annular gap inner diameter respectively.

[0051] Preferably, the bearing cage annular gap cross-sectional area in the distal narrowed tip section can be less than or equal to 3.5 mm². 2 , further preferred less than or equal to approximately.

[0052] 3 mm 2 and in particular preferably less than or equal to 2.8 mm 2 be.

[0053] Alternatively or cumulatively, preferably, the bearing cage annular gap cross-sectional area in the distally narrowed tip section can be less than or equal to a flow cross-sectional area in a proximal region, in particular less than or equal to a proximal shaft section annular gap cross-sectional area. The proximal shaft section annular gap cross-sectional area can refer to the region proximal to the shaft section at the transition to the handle section and / or to a region of the tool holder in the shaft section proximal to the proximal rolling bearing.

[0054] In particular, the (distal) bearing cage annular gap cross-sectional area can be less than or equal to 85%, more preferably less than or equal to 80%, and especially preferably less than or equal to 76.5% of the proximal shaft section annular gap cross-sectional area.

[0055] Alternatively or cumulatively, the (distal) bearing cage annular gap cross-sectional area can be less than or equal to 150%, more preferably less than or equal to 130%, and particularly preferably less than or equal to approximately 122% of a (proximal) instrument handpiece inlet cross-sectional area. The instrument handpiece inlet cross-sectional area refers to a (freely) flowable cross-sectional area of ​​the instrument handpiece located in the connection area to the rinsing device. In particular, the instrument handpiece inlet cross-sectional area denotes a minimum of the flow cross-sectional area or a constriction when referring to the flow through the entire instrument handpiece.

[0056] Particularly preferred is an increased flow rate or volumetric flow rate and / or flow velocity of the cleaning fluid through the at least one distal rolling bearing and / or the at least one proximal rolling bearing. In particular, a longitudinal vector component of the flow velocity in the longitudinal direction of the shaft section or in the longitudinal direction of the tip section is increased. This has the advantage of avoiding zones with an insufficient flow velocity of the cleaning fluid for effective mechanical cleaning and / or dead zones.

[0057] The increase in flow velocity, particularly the longitudinal vector component, through or along the inner rolling bearing can be measured or quantified according to a respective bearing cage intensification factor: On the one hand, the respective bearing cage intensification factor, with regard to a primary or first bearing cage intensification factor, can be measured in comparison to or in relation to a situation as disclosed, i.e., with a narrowed distal tip section, to a conventional situation as described in the introduction, i.e., without the presence of a narrowed distal tip section.

[0058] Preferably, the first bearing cage intensification factor, particularly with respect to the distal rolling bearing, can be greater than or equal to 1.5, more preferably greater than or equal to 2.5, and most preferably greater than or equal to 3. Since the flow velocity is incorporated into the calculation of a term for the kinetic energy of a flow with a quadratic exponent, an increase in the first bearing cage intensification factor results in a noticeable increase in the kinetic energy and thus in the mechanical cleaning performance. In particular, it ensures that all zones or surfaces to be cleaned are reliably flushed and powerfully cleaned by the fluid.

[0059] Secondly, the respective bearing cage intensification factor, which relates to a secondary or second bearing cage intensification factor, can be determined in comparison to or in relation to a situation as disclosed, i.e., with a narrowed distal tip section. Accordingly, the second bearing cage intensification factor for the further preferred embodiment with the continuous bearing cage indicates how it further improves the situation as disclosed with a narrowed distal tip section (without the continuous bearing cage). Preferably, the second bearing cage intensification factor, particularly with respect to the distal rolling bearing, can be greater than or equal to 1.1, more preferably greater than or equal to 1.5, and particularly preferably greater than or equal to 2.

[0060] In the preferred embodiment with internal rolling bearing in the form of a continuous bearing cage, the reference length for the Reynolds number is defined as the width of the bearing cage annular gap. The width of the bearing cage annular gap is determined by subtracting the inner diameter of the annular gap from the inner surface section diameter. For further details, see the above disclosures regarding the Reynolds number. In the preferred embodiment, it is particularly advantageous that the Reynolds number is reduced. Specifically, with regard to the flow, an otherwise (initially) turbulent region can be transformed into a laminar region by inserting the bearing cage and thus correspondingly reducing the reference length.

[0061] In this embodiment with internal rolling bearings, preferably with a continuous bearing cage, advantages are achieved in that the cleaning effect during internal rinsing of the instrument handpiece is further improved by targeted flow guidance of the cleaning fluid. In particular, forced flow or forced convection of the cleaning fluid occurs through the at least one distal rolling bearing and / or the at least one proximal rolling bearing, ensuring intensive rinsing of the rolling elements. Consequently, the hydromechanical effect is even further enhanced when the continuous bearing cage is present. This also ensures effective cleaning of the rinsing device, especially the cleaning and disinfection unit, even with a large number of connected instrument handpieces.Reliable fluid cleaning is ensured at a particularly large number, especially (almost) all of the provided inlet connections, adapters, or flanges. In other words, even with small partial flow rates, into which the total volume flow of cleaning fluid available to the rinsing device is divided or split according to the number of connected instrument handpieces, sufficient fluid flow and consequently a sufficiently strong mechanical cleaning effect are guaranteed.

[0062] As already explained above, the surgical instrument handpiece is designed to be inserted into a rinsing device, such as a cleaning and disinfection unit, to allow internal rinsing of the instrument handpiece with a cleaning fluid, preferably a hydrophilic or lipophilic cleaning solution, in a flow direction from proximal to distal. In the case of the preferred embodiment of the surgical instrument handpiece described directly above (with, in particular, a continuous bearing cage), the rinsing pressure at the distal outlet is preferably greater than 600 mbar, preferably greater than 700 mbar, and more preferably approximately 800 mbar. Thus, this particularly preferred embodiment ensures highly effective cleaning.

[0063] Preferably, the bearing cage is completely enclosed. This has the advantage of maximizing the cleaning power for the distal rolling bearings. Alternatively, the bearing cage is fluid-permeable to a small area-related fraction of the hole volume. This fraction can preferably be 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 achieving the most uniform cleaning effect possible, based on a refined flow pattern across the bearing cage. The latter can be achieved, for example, by means of fluid dynamic modeling or by calculation methods using finite volume elements of the internal flow space of the instrument handpiece.

[0064] Preferably, the at least one distal rolling bearing and / or the at least one proximal rolling bearing, preferably all rolling bearings of the inner rolling arrangement, have non-spherical rolling elements. It is further preferred that the at least one distal rolling bearing and / or the at least one proximal rolling bearing is designed as a cylindrical roller bearing and / or as a needle roller bearing. The rolling elements of cylindrical roller bearings are circular cylinders. Cylindrical roller bearings are manufactured in various designs, as described in DIN standard 5412, the disclosure of which is incorporated by reference. A needle roller bearing has circular cylindrical rolling elements, referred to as needles, which have very large lengths in relation to the rolling element diameter (ratio factor greater than or equal to approximately 2.5). Needle roller bearings are standardized in DIN standard 617, the disclosure of which is incorporated by reference.In these preferred embodiments with non-spherical rolling elements, the rolling bearing is characterized by a high radial load-carrying capacity and a flat or compact design. Furthermore, when internally flushed with a cleaning fluid, the tendency towards uneven or pulsating flow behavior is reduced in cylindrical roller bearings and / or needle roller bearings compared to spherical rolling elements or ball bearings. This is achieved by the reduced gap channel width between the outer surface of the bearing cage and the inner circumferential surface of the shaft section. Consequently, the cleaning effect is also advantageously enhanced.

[0065] Preferably, at least one distal rolling bearing and / or at least one proximal rolling bearing, and preferably all rolling bearings of the inner bearing arrangement, feature ceramic rolling elements, e.g., ceramic needles. This improves the mechanical load-bearing capacity, especially the fatigue strength, which leads to longer service life and maintenance intervals. Furthermore, the rolling elements can be made even smaller, allowing for an even flatter rolling element design. This further reduces the gap width between the outer surface of the bearing cage and the inner circumferential surface of the shaft section. It is also conceivable to use all-ceramic bearings. In particular, in addition to the rolling elements, the bearing rings are also made of ceramic materials.

[0066] As a second aspect of the present disclosure, a surgical instrument is proposed comprising an instrument handpiece as disclosed and a tool, preferably rotatably driven and / or driveable. Preferably, a tool comprises a milling cutter, e.g., a fine or coarse diamond milling cutter, a ("twin-cut") ball milling cutter, a pin milling cutter, a spiral or straight craniotomy cutter, etc., and / or a drill, e.g., a twist drill, and / or a polishing head and / or a rotary blade. The tool may also be a stationary tool, e.g., an electric scalpel, a cautery, a laser, or the like. Nominal diameters of the tool may preferably range from 1.0 mm to 6.0 mm.

[0067] As a third aspect of the present disclosure, a medical product set comprising at least one instrument handpiece as disclosed, in combination with at least one accessory, is proposed. Preferably, the medical product set is an application-specific assembly for a user such as a surgeon. It is preferred that an instrument handpiece as disclosed is combined with a surgical instrument as disclosed. Alternatively or cumulatively, the combination with at least one accessory of the product set comprises a variety of different, in particular rotatably driven and / or driveable, medical tools. This preferably relates to an assembly of tools of different functions or types, such as drills, milling cutters, etc., and / or of straight and / or curved shape and / or of different sizes, such as pediatric, standard, etc.short, long, etc., and / or according to hardening grades and / or according to materials. Alternatively or cumulatively, the combination with at least one accessory of the product set comprises a second instrument handpiece as disclosed, wherein the first instrument handpiece and the second instrument handpiece have different first diameters and / or different second diameters and / or different first lengths and / or different second lengths. Alternatively or cumulatively, the combination with at least one accessory comprises a tool wrench for inserting a related tool into the instrument handpiece.

[0068] Such a product set offers the distinct advantage that the manufacturer ensures that the accessories used by a user, such as the surgeon and / or clinical staff, are optimally compatible and functionally coordinated. Users perceive such a product set as particularly useful. Further application-related advantages include increased flexibility, safer handling, and improved logistical workflows within the hospital, both in surgical preparation and in the Central Sterile Supply Department (CSSD).

[0069] A fourth aspect of the present disclosure proposes a rinsing device, such as a washer-disinfector, designed for internal rinsing of an instrument handle as described in the disclosure. A washer-disinfector, also called a thermal disinfector, is used for the automated reprocessing of reusable medical devices such as surgical instruments. Thus, the Central Sterile Supply Department (CSSD) is provided with a device optimally designed by the manufacturer for cleaning the instrument handle as described in the disclosure.

[0070] As a fifth aspect of the present disclosure, a cleaning method for internally rinsing an instrument handpiece according to the disclosure in a flow direction from proximal to distal in a rinsing device according to the disclosure is proposed. In this way, cleaning efficiency and / or the achievable degree of sterilization are improved.

[0071] Preferably, the cleaning method according to the disclosure is further hydrodynamically optimized and designed such that streamlines of a cleaning fluid, which preferably run through the proximal rolling bearing, include streamlines that run along an outer surface of the continuous bearing cage and / or through the at least one distal rolling bearing. This further prevents incomplete or insufficient flow of cleaning fluid.

[0072] Finally, it should be noted that the instrument handpiece disclosed is not limited to use solely in surgery. The disclosure is equally advantageous for similar medical applications, in particular for a variety of dental and orthopedic situations and procedures, as well as diagnostic methods and examination techniques. The field of application encompasses both human and veterinary medicine. The inventive concept is directed towards any application of an instrument handpiece for holding a tool, especially one rotatably mounted, where reliable cleaning by internal rinsing after use or tool removal is essential for reuse and / or where the smallest possible distal design is crucial.

[0073] The scope of protection of the present disclosure is defined by the claims and is not limited by the features explained in the description or shown in the figures. Brief description of the figures

[0074] Fig. 1 is a slightly perspective side view of an instrument handpiece (without tool) in an embodiment according to the prior art;

[0075] Fig. 2 is a side view of the instrument handpiece (without tool) in the embodiment according to the prior art;

[0076] Fig. 3a is a distal detail section of a lateral sectional view of the instrument handpiece (without tool) in the embodiment according to the prior art, in particular illustrating the internal rolling bearing for a tool;

[0077] Fig. 3b, corresponding to the distal detail section of Fig. 3a, is a schematic representation of hydrodynamic streamlines, in particular illustrating the internal flow with a cleaning fluid;

[0078] Fig. 4 is a slightly perspective side view of the instrument handpiece according to the disclosure (without tool) in a preferred embodiment;

[0079] Fig. 5 is a side view of the instrument handpiece (without tool) according to the disclosure in the preferred embodiment;

[0080] Fig. 6a is a distal detail section of a lateral sectional view of the instrument handpiece according to the disclosure (without tool) in the preferred embodiment, in particular illustrating the internal rolling bearing for a tool;

[0081] Fig. 6b, corresponding to the distal detail section of Fig. 6a, is a schematic representation of hydrodynamic streamlines, in particular illustrating the internal flow through the instrument handpiece (without tool) according to the disclosed embodiment with a cleaning fluid; Fig. 7 is a slightly perspective side view of a preferred bearing cage in the form of an extract view as a separate component for the interior of the instrument handpiece according to the disclosed embodiment;

[0082] Fig. 8a is a first sectional view of the instrument handpiece (without tool), showing a proximal area of ​​a tool holder in a shaft section to a proximal rolling bearing, in the embodiment according to the prior art;

[0083] Fig. 8b is a second sectional view of the instrument handpiece (without tool), distal to the first sectional view of Fig. 8a, showing the proximal rolling bearing in the shaft section, in the embodiment according to the prior art;

[0084] Fig. 9 is a sectional view of the instrument handpiece according to the disclosure, showing a region proximal to the shaft section in the transition to a handle section;

[0085] Fig. 10a is a first sectional view of the instrument handpiece according to the disclosure (without tool), showing the area of ​​the tool holder in the shaft section proximal to the proximal rolling bearing, according to the preferred embodiment; and

[0086] Fig. 10b is a second sectional view of the instrument handpiece according to the disclosure (without tool), distal to the first sectional view of Fig. 10a, showing a central area of ​​the bearing cage according to Fig. 7 in the distal narrowed tip section, according to the preferred embodiment.

[0087] Description of the exemplary embodiment

[0088] An embodiment of the present disclosure is described below based on the associated Figures 4 to 6b, Figure 7, and Figures 9 to 10b, and is thus compared to an embodiment according to the prior art as shown in Figures 1 to 3b and Figures 8a and 8b. This reveals further details, features, and advantages of the disclosure.

[0089] Insofar as the instrument handpiece according to the disclosed designation in the preferred embodiment according to Figures 4 to 6b and Figures 10a and 10b is similar to the embodiment according to the prior art according to the analogous Figures 1 to 3b and the analogous Figures 8a and 8b, or insofar as no difference feature according to the disclosed designation is discussed, reference is made to the introductory description or the designations relating to the prior art in order to avoid repetition.

[0090] Figures 1 and 2 show a slightly perspective side view and a side view, respectively, of an instrument handpiece (without a tool) in a prior art embodiment. A surgical instrument handpiece 1 for a surgical instrument comprises an integrally formed handle section 7, which can be handled proximally (away from the patient) by a surgeon (not shown), and a shaft section 8 extending distally (towards the patient) from the handle section 7. A tool (not shown), such as a diamond burr or a twist drill, can be positioned by a user at the distal end of the shaft section 8, opposite the handle section 7, in a cylindrical bore 40, serving as the distal exit opening.The tool (not shown) typically comprises a tool head, such as a drilling, milling, grinding or polishing head, and a tool shank for insertion into the cylinder bore 40.

[0091] Furthermore, the instrument handpiece 1 has a connection 5 at its proximal end (away from the patient) by means of which it can be connected to a torque transmission system, a drive unit, a power supply unit or similar, as known from the prior art.

[0092] Between the cylindrical bore 40 at the distal end, which is designed to receive the tool, and the connection 5, a handle section 7 with a surface profile 12 (nubs, grooves, etc.) is formed, to which a cylindrical shaft section 8 extends distally. The surface profile 12 consists of radial and axial depressions with raised areas between them. The instrument handpiece 1 is usually grasped by the operator at the handle section 7 and handled during use.

[0093] The cylindrical shaft section 8 is designed with a constant second diameter D2 (see Fig. 2).

[0094] Furthermore, Figures 3a and 3b each show the same distal detail of a lateral sectional view of the instrument handpiece (without tool) according to the prior art: firstly (Fig. 3a) without fluid flow, as in a conventional workshop drawing, and secondly in the manner of a hydrodynamic schematic representation in a fluid-flowing state (Fig. 3b). For the sake of clarity, only the streamlines S in Fig. 3b are labeled with a reference numeral; therefore, for the purposes of the following description, reference is made to the designation of the components with reference numerals in the corresponding Fig. 3a.

[0095] These illustrations in Figures 3a and 3b show, in particular, the entire internal rolling bearing assembly. This assembly is designed for the rotatable mounting of a rotary-driven tool (not shown) inside the instrument handpiece 1, specifically the shaft section 8. Therefore, the views in Figures 3a and 3b are interrupted, as indicated by the dashed line (at the right edge of the image). The entire rolling bearing assembly comprises a distal ball bearing pair 20, formed from two distal rolling bearings (left in the image), and a proximal ball bearing pair 22, formed from two proximal rolling bearings 22 (right in the image). All four individual ball bearings, namely those of the distal ball bearing pair 20 and the proximal ball bearing pair 22, are of identical construction. Each individual ball bearing comprises a multitude of balls 30 as round rolling elements, which roll between a respective inner ring 26 and a respective outer ring 24.rolling onto these, spaced apart from each other. The respective outer ring 24 is fitted into a distal cylindrical inner surface section 33 of the shaft section 8. Furthermore, in this sectional view of Figs. 3a and 3b, an inner tool receptacle 19 for folding or anchoring the tool shaft (not shown) and a guide sleeve 32 are visible at the proximal end of the shaft section 8. The tool (not shown), inserted through the cylindrical bore 40 at the distal end of the tool, is preferably held or coupled in the tool receptacle 19 and guide sleeve 32 of the instrument handpiece 1 in a replaceable manner and can be driven rotaryally via the proximal connection 5 (see Figures 1 and 2).

[0096] The hydrodynamic schematic in Fig. 3b illustrates a fluid-flow state of the instrument handpiece 1 by means of streamlines S drawn as lines. Such a fluid-flow state occurs when the instrument handpiece 1 is inserted into a rinsing device (not shown), such as a cleaning and disinfection unit. The elongated streamlines S represent an internal rinsing of the instrument handpiece 1 with a cleaning fluid, preferably a hydrophilic or lipophilic cleaning solution, in the flow direction from proximal to distal. The streamlines S thus emerge from the distal outlet opening 40 (left in the image).

[0097] The flow through the entire rolling bearing assembly from the proximal ball bearing pair 22 (right in the image) to the distal ball bearing pair 20 (left in the image) is clearly visible in the streamline S of Fig. 3b: Initially, a forced flow – and thus hydrodynamically effective cleaning – occurs through the proximal ball bearing pair 22, due to the design, as the flow flows around the associated balls 30. Upon exiting the proximal ball bearing pair 22, however, the flow seeks a downward or distal path essentially towards the central axis of the shaft section (corresponding to the path of least resistance). Finally, the majority of the cleaning fluid flows through the comparatively large cylindrical opening.The fluid exits the bore of the paired inner rings 26, 26 of the distal ball bearing pair 20 and then exits the interior of the shaft section 8 via the distal outlet opening 40. Therefore, according to the prior art, the distal ball bearing pair 20 (left in the image) is hardly subjected to fluid flow and thus not adequately cleaned.

[0098] The flow path and flow conditions described above, from proximal to distal, through the instrument handpiece 1 in the prior art embodiment are further illustrated in detail with reference to Figures 8a and 8b. Figure 8a shows a first sectional view of the conventional instrument handpiece 1 (without tool), which relates to a cross-section through the cylindrical shaft section 8 with a constant second diameter D2 (see also Figure 2). The first sectional view in Figure 8a is located in a region of the tool holder 19 (see also Figure 3a) that is positioned more proximal than the proximal rolling bearing 22 (Figure 22). Furthermore, Figure 8b shows a second sectional view of the conventional instrument handpiece (without tool), which is sectioned distal to the first sectional view in Figure 8a, i.e., further downstream in the flow direction. The second sectional view in Figure 8a...8b the proximal rolling bearing 22 in the shaft section 8 with the second diameter 8.

[0099] In the first and second sectional views (for the prior art: in Figures 8a and 8b), particular reference is made to the hydrodynamic schematic representation (for the prior art: in Fig. 3b), which illustrates the fluid-flow state of the instrument handpiece 1 by means of the linearly drawn streamlines S (or an exemplary selection of the two streamlines from a real multitude).

[0100] The streamlines S emerge from a plane of the sheet referenced to the cross-sectional view (for the prior art: in Figures 8a and 8b); that is, (ideally) as points pointing towards the viewer. Each streamline S (shown as an example or selection) is represented as a point, like the tip of an arrow representing a corresponding flow vector of a flow velocity passing through the plane of the sheet.

[0101] Thus, the respective streamline S, which appears as a point in the cross-sectional view, designates a cross-sectional area through which the fluid flows or an open cross-sectional area, or an associated flow cross-sectional area. In other words, a point marked by the streamline S in one of the cross-sectional views indicates a (discernible or individual) (flow) cross-sectional area that is available for a flow path. Therefore, during flushing with the cleaning fluid using the (not shown) flushing device, preferably the cleaning and disinfection unit, the (respective) flow cross-sectional area is in fluid contact with an inlet connection of the instrument handpiece 1.

[0102] The first sectional view in Figure 8a shows that a cylindrical annular gap cross-sectional area AR is formed between an outer cylindrical annular gap outer diameter d-R1 and an inner annular gap inner diameter d-R2, through which flow (with a point-like emerging streamline S) is formed. Thus, the annular gap cross-sectional area AR is calculated as a (respective flow) cross-sectional area by subtracting the two circular areas with the annular gap outer diameter d-R1 and the annular gap inner diameter d-R2, respectively. For example, the annular gap cross-sectional area AR can be 2.4 mm², as shown in Figure 8a. 2 be.

[0103] The second sectional view in Figure 8b shows the flow situation downstream or distally. Here, in the proximal rolling bearing 22, the flow passes through two flow chambers (or respective flow cross-sectional areas) separated by the inner ring 26. Together, these form a total rolling bearing flow cross-section (e.g., 8.5 mm²). 2 ), as explained below: The proximal rolling bearing 22 is represented by seven balls 30 as the rolling elements, which roll between the inner ring 26 with inner ring diameter d-26 and the outer ring 24 with outer ring diameter d-26, which is fitted into the shaft section 8. Part of the flow passes (with a point-like streamline S) centrally through a cylindrical bore interior of the inner ring 26 with a bore cross-sectional area AB (e.g., 4.5 mm²). 2) according to a bore diameter dB (e.g., 2.4 mm). Additionally, the other part of the flow encloses a rolling bearing interior formed between the inner ring 26 and the outer ring 24, free of the (seven) balls 30, of the proximal rolling bearing 22 with a (free) rolling bearing cross-sectional area A-22 (e.g., 4.0 mm²). 2 ), with two point-like emerging streamlines S, through which flow occurs.

[0104] According to the flow law of the path of least resistance and / or according to the flow condition known as the wall adhesion condition, especially in the case of pipe flow, and / or according to the flow through a packed bed ("Pre-Darcy"), the hydrodynamic distribution of the flow velocity (in the longitudinal direction of the instrument handpiece 1) results with a maximum within the bore cross-sectional area AB. In contrast, the other part of the flow through the rolling bearing cross-sectional area A-22 occurs only to a small extent or is comparatively smaller than the first part.

[0105] In other words, the design of the conventional instrument handpiece 1 results in a disadvantageous situation where, when cleaning fluid flows through it, the rolling bearing (or, in this case, the proximal rolling bearing 22, discussed here as a representative hydrodynamic component) is only subjected to a small, weak, or slow flow. The fact that the flow cross-section is reduced proximally (the annular gap cross-sectional area AR, for example, 2.4 mm²) is considered particularly disadvantageous in the prior art. 2 ) not only does it not taper, but it even widens distally (total rolling bearing flow cross-section e.g. 8.5 mm²). 2 ) expands considerably. Consequently, there is a risk that the cleaning fluid will not provide sufficient mechanical cleaning. In particular, the mechanical cleaning effect is determined by the kinetic energy of the cleaning fluid as a hydrodynamic quantity, which in turn is influenced by the square of the flow rate.

[0106] The aforementioned disadvantage of the reduced flow rate and thus diminished cleaning effect in the rolling bearing is all the more significant with regard to the technical goal of hygiene, in particular completely reliable sterilization, since the large surfaces of the rolling bearings offer a particularly large area for the adhesion of contaminants such as germs, biofilms and the like.

[0107] Based on the first and second sectional views of the conventional instrument handpiece in Figures 8a and 8b, the disadvantage of the prior art already described above with reference to Fig. 3b becomes particularly clear, namely the insufficient (fluid) cleaning effect of the flow visualized by means of the streamlines S.

[0108] According to the present disclosure, this problem is remedied. Figures 4 to 7 show different views according to an embodiment of an instrument handpiece 1 as disclosed. Thus, Figures 4 and 5 [by analogy to Figures 1 and 2 for the prior art] show a slightly perspective side view and a side view, respectively, of the instrument handpiece as disclosed (without tool) in a preferred embodiment.

[0109] Unlike the prior art, the shaft section 8 has a narrowed distal tip section 10 in the region of the distal outlet opening 40 (left in Figures 4 to 6b). The distal tip section 10 narrows from a second diameter D2 of the shaft section 8 down to a smaller first diameter D1 (see Figure 5). In other words, the preferred embodiment of an instrument handpiece according to the disclosure shown in Figures 4 to 7 differs from the conventional instrument handpiece according to the prior art, as shown in Figures 1 to 3b, in that the elongated shaft section 8 with a second diameter D2 has a narrowed distal tip section 10 in its distal region of the cylindrical bore 40 as the distal outlet opening.

[0110] As indicated by curly brackets in Fig. 4, the first length L1 of the distal tip section 10 occupies a distal subsection of the (entire) second length L2 of the (entire) shaft section 8. Between the distal tip section 10 with the first diameter D1 and the shaft section 8 with the second diameter D2, a step or sloping ramp is formed around the circumference as a transition area 11 (see Fig. 5), tapering or beveling gradually.

[0111] Furthermore, Figures 6a and 6b [by analogy to Figures 3a and 3b for the prior art] each show the same distal detail of a lateral sectional view of the instrument handpiece according to the disclosure (without tool) in the preferred embodiment: firstly (Figure 6a) without flow, as in a workshop drawing; secondly, with fluid flow (Figure 6b). For the sake of clarity, only the streamlines S and the outlet cross-sectional area A for the flow are provided with a reference numeral in Figure 6b, which is why, for the purposes of the following description, reference is made to the designation of the components with reference numerals in the corresponding Figure 6a.

[0112] These illustrations in Figs. 6a and 6b show, in particular, the entire internal rolling bearing. This bearing, for the rotatable arrangement of a rotaryally driven tool (not shown), is provided inside the instrument handpiece 1, especially in the distal tip section 10 of the shaft section 8.

[0113] As indicated by the dashed line (at the right edge of the image), the views of Figs. 6a and 6b (like those of Figs. 3a and 3b) are interrupted. The entire rolling bearing assembly comprises a distal needle roller bearing (or cylindrical roller bearing) 20 (left in the image) and an identical proximal needle roller bearing (or cylindrical roller bearing) 22 (right in the image). The distal needle roller bearing 20 and the proximal needle roller bearing 22 each comprise a plurality of needles 30, preferably ceramic, as elongated or oblong non-spherical rolling elements, distributed in uniform angular segments around a respective circumference. The respective needles 30 are rotatably mounted or arranged in a plurality of associated longitudinal grooves 35 in the bearing cage 50 about their longitudinal center axis.The distal needle bearing 20 and the proximal needle bearing 22 are spaced apart from each other in the longitudinal direction of the shaft section 8 by means of a cylindrical bearing cage 50 inserted into the cylindrical inner bore of the distal shaft section 10. The respective needles 30 of the distal needle bearing 20 and the proximal needle bearing 22 thus roll or glide on the inside of a cylindrical inner surface section 33 of the distal tip section 10 and the shaft section 8, respectively. Similar to the prior art, an internal tool receptacle 19 for holding or anchoring the tool shaft (not shown) and a guide sleeve 32 are visible at the proximal end of the shaft section 8.

[0114] Fig. 6b, like Fig. 3b for the prior art, shows a schematic representation of hydrodynamic streamlines S. Therefore, unless there are differences from the prior art, reference is made to the explanations in Fig. 3b to avoid repetition. In contrast to Fig. 3b, Fig. 6b illustrates a fluid-flow state according to the disclosure when the instrument handpiece according to the disclosure (without a tool) is internally permeated by a cleaning fluid according to the preferred embodiment. Such a fluid-flow state according to the disclosure can preferably be brought about or set by inserting the instrument handpiece 1 according to the disclosure into a (not shown) rinsing device according to the disclosure, such as a cleaning and disinfection device.The elongated streamlines S represent an internal flushing of the instrument handpiece 1 with a cleaning fluid, preferably a hydrophilic or lipophilic cleaning solution, in the flow direction from proximal to distal (from right to left in the image). In this respect, the streamlines S emerge from the distal outlet opening 40 (left in the image) of the narrowed distal tip section 10 with a correspondingly reduced outlet cross-sectional area A of the flow.

[0115] The flow pattern of the streamlines S in Fig. 6b clearly shows the flow through the distal needle bearing 20 as a distal rolling bearing. Almost along the entire length of the shaft section 8, and particularly along the first length L1 of the distal tip section, the streamlines run along the inner surface section 33 of the distal tip section 10 or the shaft section 8. Specifically, only after passing through the distal needle bearing 20, or shortly before exiting the distal outlet opening 40 with a reduced outlet cross-sectional area A, does the flow path downstream, essentially towards the central axis of the shaft section. Thus, as shown, a hydrodynamically effective (fluid) cleaning of the distal needle bearing 20 as a distal rolling bearing also takes place.Because of the narrowed distal tip section 10, as shown, the flow velocity (corresponding to the reduced outlet cross-sectional area A) and the pressure in the distal tip section 10 of the instrument handpiece 1 are increased to improve the cleaning effect. This results in a change in the diameter of the distal tip section 10 from an outer diameter of 5.6 mm (example second diameter D2) to an outer diameter of 4.4 mm (example first diameter D1) within the first 20 mm (example first length L1).

[0116] Furthermore, the special design of the bearing cage 50 as a continuous tube ensures less soiling during use and, at the same time, optimized cleaning through the targeted flow of the cleaning fluid. A small portion of the cleaning fluid also passes through the tool opening 40, the distal outlet of the instrument handpiece 1, ensuring optimal cleaning here as well, since no obstructing parts block the flow of the cleaning fluid. Figures 6a and 6b illustrate the design details regarding the installation and assembly of the bearing cage 50, which is shown in more detail as a separate component in Figure 7.

[0117] The technical effect on the flow lines S due to the design and arrangement of the particularly preferred embodiment with a bearing cage 50 can be seen particularly clearly in Fig. 6b. It becomes apparent that the bearing cage 50 even causes a forced flow through the distal needle bearing 20; that is, it passes through and is thus (fluid) cleaned. In particular, the installation of such a bearing cage 50 advantageously achieves a high degree of independence from a proximally applied inlet pressure of the cleaning fluid, which further contributes to the stability of a cleaning process according to the disclosure.

[0118] Fig. 7 shows, in the form of an enlarged detail view with reference to Fig. 6a and Fig. 6b, a slightly perspective side view of a bearing cage 50, as it may preferably be provided as a separate component of a rolling bearing for the tool inside the instrument handpiece 1 according to the disclosure. This view in Fig. 7 clearly shows that the bearing cage 50, in the form of a cylindrical tube, arranges a distal rolling bearing 20 (left in the image) and a proximal rolling bearing 22 (right in the image) at a distance from each other. The distal rolling bearing 20 and the proximal rolling bearing 22 are each designed by means of five needles 30, which are evenly distributed around the circumference of the bearing cage 50 and serve as non-spherical rolling elements. The needles 30 in turn are arranged to rotate or roll about their longitudinal axis in associated longitudinal grooves 35 of the bearing cage 50.Furthermore, a large number of round guide elements 60 and a sliding surface 61 can be seen at the proximal end of the bearing cage 50.

[0119] Fig. 9 shows a sectional view of the instrument handpiece 1 according to the disclosure, which depicts a region proximal to the shaft section 8 at the transition 12 to a handle section 7 (according to Fig. 4). It can be seen that an annular gap cross-sectional area AR corresponding to the cross-section of Fig. 9 (e.g., approx. 3.6 mm²) 2 ) between an associated outer cylindrical annular gap outer diameter d-R1 (e.g. approx. 3.2 mm) and an associated inner annular gap inner diameter d-R2 (e.g. approx. 2.4 mm), for flow through (with a point-like emerging streamline S).

[0120] Furthermore, Fig. 10a and Fig. 10b [by analogy to Fig. 8a and Fig. 8b for the prior art] show a first and a second side view of the instrument handpiece 1 according to the disclosure (without tool) in the preferred embodiment according to Figures 4 to 7: Fig. 10a shows a first sectional view in a region of the tool holder 19 in the shaft section 8 with the second diameter D2, proximal to the proximal rolling bearing 22 (according to Figure 6a).

[0121] Furthermore, Fig. 10b shows a second sectional view, distal to the first sectional view of Fig. 10a, of a central area of ​​the bearing cage 50 (according to Figures 6a and 7) in the distal narrowed tip section 10 as disclosed, with the first diameter D1.

[0122] Analogous to the preceding discussion for the prior art (based on the relevant figures 8a and 8b), in the first and second sectional views of figures 10a and 10b respectively, particular reference is made to the hydrodynamic schematic representation in Fig. 6b, which illustrates the fluid-flow state of the instrument handpiece 1 by means of the linearly drawn streamlines S (or an exemplary selection of the two streamlines from a real multitude).

[0123] Fig. 10a shows that an annular gap cross-sectional area AR (e.g. approx. 3.6 mm) corresponding to the cross-section of the shaft section 8 in Fig. 10a (cylindrical) 2 ) between an associated outer cylindrical annular gap outer diameter d-R1 (e.g. approx. 4.5 mm) and an associated inner annular gap inner diameter d-R2 (e.g. approx. 4.0 mm), for flow through (with a point-like emerging streamline S).

[0124] It is therefore particularly preferred that the annular gap cross-sectional area AR corresponding to the cross-section of the shaft section 8 in Fig. 10a corresponds approximately to the (cylindrical) annular gap cross-sectional area AR corresponding to the cross-section of Fig. 9 (area ratio of 90% to 110%, more preferably 98% to 102%, in particular approximately 100%). This results in an advantageous uniformity of the course of the rinsing pressure, the flow velocity, or the kinetic energy in the instrument handpiece 1 from proximal to distal.

[0125] Fig. 10b, concerning a distal cross-section as disclosed, shows, with reference to Fig. 6a and Fig. 6b respectively, that the distally narrowed tip section 10 with the first diameter D1 surrounds the cylindrical bearing cage 50 (extending longitudinally in the instrument handpiece 1) at an internal distance. An annular gap is formed around the bearing cage 50 to allow flow (with a point-like emerging streamline S). However, at least the proximal end, and preferably also the distal end, of the bearing cage 50 is closed, so that the central cylindrical volume of the bearing cage 50 cannot be, and is not, flowed through.

[0126] Behind the cross-section of the distal tip section 10 shown in Fig. 10b through a (longitudinally) central area of ​​the bearing cage 50, the five needles 30, evenly distributed around the circumference of the bearing cage 50, can be seen as non-spherical rolling elements (see Fig. 7).

[0127] The associated annular gap is located within the inner surface section 33 on an outer surface of the continuous bearing cage 50, between an inner surface section diameter d-33 (e.g., approx. 3.8 mm) as the outer diameter of the annular gap and a bearing cage outer diameter d-50 (e.g., approx. 3.3 mm) as the inner diameter of the annular gap. The annular gap arranged around the bearing cage 50 has a bearing cage annular gap cross-sectional area A-50 (e.g., approx. 2.8 mm²). 2 ) on.

[0128] Preferably, the bearing cage annular gap cross-sectional area A-50 can be less than or equal to 3.5 mm 2 , preferably less than or equal to approximately 3 mm 2 and in particular preferably less than or equal to 2.8 mm 2Alternatively or cumulatively, the bearing cage annular gap cross-sectional area A-50 can be less than or equal to a flow cross-sectional area that is freely permeable in a proximal region of the instrument handpiece 1, as shown, for example, in Figures 10a and / or 9. More preferably, the bearing cage annular gap cross-sectional area A-50 can be less than or equal to a proximal shaft section annular gap cross-sectional area AR (see Fig. 9).

[0129] In particular, as disclosed, the rinsing pressure at the distal outlet opening (reference 40, see Figures 4 to 6a) or in the bearing cage annular gap cross-sectional area A-50 is positively increased in the flow direction from proximal to distal. Thus, the instrument handpiece according to the disclosed design provides a remedy for the technically problematic situation in the prior art, which can occur in the form of a potentially insufficient rinsing pressure, especially in situations with high clinical utilization. For example, the total proximal inlet pressure of the cleaning fluid supplied externally to several connected instrument handpieces to be cleaned in a (not shown) cleaning and disinfection device (e.g., of type "MIELE G 7825", construction 80) can be a maximum of approximately 1600 mbar as a proximal absolute pressure. This results in a pressure difference or...Due to a pressure excess or a pressure delta compared to the atmospheric ambient pressure of, for example, approximately 950 mbar, the maximum (proximal) rinsing pressure for a single connected instrument handpiece 1 is approximately 650 mbar. However, this maximum (proximal) rinsing pressure is divided among multiple instrument handpieces when they are present or connected, thus reducing the rinsing pressure for each handpiece. The exemplary cleaning and disinfection device provides a maximum of 22 connections ("Luer-Lock: Miele type"; connection inner diameter 3 mm; therefore flow cross-section: A = approximately 7 mm²). 2) ready. In the case of 11 connected instrument handpieces, i.e., half, a reduction of the respective (proximal) rinsing pressure to approximately 500 mbar proximally was observed. In the case of 22 (out of 22) connected instrument handpieces, it was recorded that the respective (proximal) rinsing pressure decreased even further to approximately 315 mbar proximally. The respective (proximal) rinsing pressure is therefore available at the inlet of the instrument handpiece (proximal handle section - flow cross-section e.g. Ø 1.7 mm, A = 2.27 mm²). 2 ).

[0130] The proximal rinsing pressure applied by the exemplary cleaning and disinfection device is further reduced, taking into account various flow resistances such as pipe friction along the internal flow through the instrument handpiece, from proximal to distal, to a distal rinsing pressure.

[0131] The present disclosure ensures that reliable and sufficient fluid cleaning occurs even at lower rinsing pressures. The narrowed distal tip section 10 ensures that an effective rinsing pressure is maintained even in the distal region. In particular, the especially preferred embodiment with the continuous bearing cage 50 creates a powerful forced flow in the surrounding bearing cage annular gap cross-sectional area A-50. Thus, despite flow pressure losses, effective fluid cleaning still occurs downstream or distal to the unnarrowed shaft section 8, namely in the distal tip section 10. This ensures virtually undiminished mechanical cleaning performance in the distal rolling bearing 20 and in the proximal rolling bearing 22. In this respect, even the proximal rolling bearing 22 receives the full rinsing flow of the cleaning fluid. Reference numeral

[0132] 1 instrument handpiece

[0133] 5 connection

[0134] 7 Handle section

[0135] 8 shaft section

[0136] 10 distal tip section

[0137] 11 Transition area

[0138] 12 Profiling

[0139] 19 Tool holder

[0140] 20 distal rolling bearing

[0141] 22 proximal rolling bearing

[0142] 24 outer ring

[0143] 26 inner ring

[0144] 30 rolling elements

[0145] 32 longitudinal groove

[0146] 33 Interior surface section

[0147] 35 Guide sleeve

[0148] 40 distal exit orifice

[0149] 50 bearing cages

[0150] 60 guide element

[0151] 61 Slip surface

[0152] A Exit cross-sectional area

[0153] AB bore cross-sectional area

[0154] AR annular gap cross-sectional area

[0155] A-22 Rolling bearing space cross-sectional area

[0156] A-50 Bearing cage annular gap cross-sectional area

[0157] D1 first diameter (of the distal tip section)

[0158] D2 second diameter (of the shaft section) dB bore diameter d-24 outer ring diameter (inside) d-26 inner ring diameter (outside) d-33 inner surface section diameter d-50 bearing cage outer diameter d-R1 annular gap outer diameter d-R2 annular gap inner diameter

[0159] L1 first length (of the distal tip section)

[0160] L2 second length (of the entire shaft section) S streamline (cleaning fluid)

Claims

Claims 1. Surgical instrument handpiece (1) for a surgical instrument comprising: a handle section (7) for proximal handling by a surgeon, and a shaft section (8) extending distally in the longitudinal direction from the handle section (7), wherein a tool is arranged or can be arranged by a user at the distal end opposite the handle section (7) in a distal exit opening (40) of the shaft section (8), characterized in that the shaft section (8) has at least one distal tip section (10) narrowed with respect to a cross-sectional area in the region of the distal exit opening (40).

2. Surgical instrument handpiece (1) according to claim 1, wherein a first diameter (D1) of the narrowed distal tip section (10) is: compared to a second diameter (D2) of an unnarrowed area of ​​the shaft section (8) by a diameter ratio factor of at most 95 percent, preferably at most 85 percent, more preferably about 79 percent; and / or is between 3.5 and 5.3 millimeters, preferably between 4.0 and 5.0 millimeters, more preferably between 4.3 and 4.5 millimeters.

3. Surgical instrument handpiece (1) according to claim 1 or 2, wherein a first length (L1) of the distal tip section (10) is: in relation to a total second length (L2) of the shaft section (8) comprising a length fraction of at least 5 percent, preferably at least 20 percent, more preferably at least 35 percent; and / or is between 5 and 40 millimeters, preferably between 10 and 30 millimeters, more preferably between 18 and 22 millimeters.

4. Surgical instrument handpiece (1) according to one of the preceding claims, wherein a shoulder extends from the narrowed distal tip section (10) to The transition area (11) formed in the unconstricted area of ​​the shaft section (8) is rounded and / or gradually tapered and / or beveled.

5. Surgical instrument handpiece (1) according to one of the preceding claims, which is designed to be inserted into a rinsing device such as a cleaning and disinfection device, such that, during internal rinsing of the instrument handpiece (1) with a cleaning fluid, preferably with a hydrophilic or lipophilic cleaning solution, in the flow direction from proximal to distal, the rinsing pressure at the distal outlet opening (40) is greater than 10 mbar, more preferably greater than 90 mbar, even more preferably greater than 160 mbar and particularly greater than 500 mbar; and / or is maintained to a proportion of at least 20 percent, preferably at least 50 percent, more preferably at least 80 percent, relative to a proximally applied inlet pressure of the cleaning fluid.

6. Surgical instrument handpiece (1) according to one of the preceding claims, wherein the shaft section (8) comprises an internal rolling bearing for rotatably mounting the arranged or arrangeable tool, preferably at least partially in the region of the narrowed distal tip section (10), wherein the rolling bearing comprises at least one distal rolling bearing (20) and at least one proximal rolling bearing (22) and wherein the at least one distal rolling bearing (20) and the at least one proximal rolling bearing (22) are spaced apart by a bearing cage (50) formed continuously between them.

7. Surgical instrument handpiece (1) according to the directly preceding claim, which is designed to be inserted into a rinsing device such as a cleaning and disinfection device, such that when the instrument handpiece (1) is internally rinsed with a cleaning fluid, preferably with a hydrophilic or lipophilic cleaning solution, the rinsing pressure at the distal outlet opening (40) in the flow direction from proximal to distal is greater than 600 mbar, preferably greater than 700 mbar and more preferably of approximately 800 mbar.

8. Surgical instrument handpiece (1) according to one of claims 6 or 7, wherein the bearing cage (50) is completely closed or is fluid-permeable to a small area-related hole volume fraction, wherein preferably the hole volume fraction is less than 40 percent, more preferably less than 15 percent, and particularly preferably less than 8 percent.

9. Surgical instrument handpiece (1) according to one of claims 6 to 8, wherein the at least one distal rolling bearing (20) and / or the at least one proximal rolling bearing (22), preferably all rolling bearings of the inner rolling bearing, have non-spherical rolling elements, preferably designed as cylindrical roller bearings and / or as needle bearings.

10. Surgical instrument handpiece (1) according to one of claims 6 to 9, wherein the at least one distal rolling bearing (20) and / or the at least one proximal rolling bearing (22), preferably all rolling bearings of the inner rolling bearing, have ceramic rolling elements.

11. Surgical instrument handpiece (1) according to one of claims 6 to 10, wherein a bearing cage annular gap cross-sectional area (A-50) of an annular gap is arranged in the distally narrowed tip section (10), which is formed on an outer lateral surface of the continuous bearing cage (50) between an inner surface section diameter (d-33) of the inner surface section (33) as an annular gap outer diameter and a bearing cage outer diameter (d-50) as an annular gap inner diameter: less than or equal to 3.5 mm 2 , preferably less than or equal to approximately 3 mm 2 and in particular preferably less than or equal to 2.8 mm 2 is; and / or is less than or equal to a flow cross-sectional area which is freely permeable in a proximal region of the instrument handpiece (1), and is further preferably less than or equal to a proximal shaft section annular gap cross-sectional area (AR) of the shaft section (8).

12. Surgical instrument comprising an instrument handpiece (1) according to one of the preceding claims and a tool, preferably rotatably driven and / or driveable.

13. Medical product set, preferably an application-specific assembly for a surgeon, comprising at least one first instrument handpiece (1) according to any of the preceding claims directed to the instrument handpiece (1), in combination with at least: one surgical instrument according to the immediately preceding claim; and / or with a plurality of different, in particular rotatably driven and / or driveable, medical tools, preferably in an assembly of tools of different functions and / or of straight and / or curved shape and / or of different sizes and / or degrees of hardness and / or materials;and / or a second instrument handpiece (1) according to any of the preceding claims directed to the instrument handpiece (1), wherein the first instrument handpiece (1) and the second instrument handpiece (2) have different first diameters (D1) and / or different second diameters (D2) and / or different first lengths (L1) and / or different second lengths (D2); and / or a tool wrench for inserting an associated tool into the instrument handpiece (1).

14. Flushing device such as a cleaning and disinfection device, configured for internal flushing of an instrument handpiece (1) according to the invention according to one of the preceding claims directed to the instrument handpiece (1).

15. Cleaning method for internal rinsing of an instrument handpiece (1) according to the invention according to one of the preceding claims directed to the instrument handpiece (1) in the direction of flow from proximal to distal in a rinsing device according to the directly preceding claim.

16. Cleaning method according to the immediately preceding claim for an instrument handpiece (1) of claims 6 to 11, characterized in that streamlines of a cleaning fluid, which preferably run through the proximal rolling bearing (22), include such streamlines which run along an outer lateral surface of the continuous bearing cage (50) and / or through the at least one distal rolling bearing (20).