SURGICAL INSTRUMENT HANDLE

Description

Technical field

[0001] 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. The present disclosure further relates to such a surgical instrument and an associated medical product set comprising the surgical instrument handpiece in combination with at least one accessory. A related cleaning method for internally rinsing the surgical instrument handpiece is also proposed.

[0002] 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 manipulating, for example, bones, cartilage, vertebrae, etc. German patent application DE 10 2013 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.

[0003] 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.

[0004] 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.

[0005] 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.

[0006] 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 10 2018 133 503.2, 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.

[0007] 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 use of the rinsing device must be described and implemented separately.

[0008] 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 current instrument handpieces, 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.

[0009] US 2017 / 0 120 451 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.

[0010] 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.

[0011] 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.

[0012] US 2003 / 023256A1 can be considered the closest prior art and discloses a surgical instrument for dissecting bone and other tissue, comprising a spindle, a dissection tool, and an adapter arranged between the spindle and the dissection tool. The spindle includes a cavity and a male element projecting into the cavity. The adapter includes a drive shaft extending along an axis and having a first end with a generally cylindrical cross-section and a centrally located opening extending partially along the axis. The male element is supported by the spindle and extends into the opening of the dissection tool. The cavity can define a drive section and a tool-receiving opening. One or more alignment projections can extend from the drive section into the tool-receiving opening.

[0013] Furthermore, DE 20 2011 050062 U1 of the present applicant discloses a generic surgical instrument with a shaft and a drive shaft rotatably mounted in the shaft, which carries or comprises a tool element at its distal end, wherein a radial bearing is arranged or formed in the distal end region of the shaft for rotatably mounting the drive shaft on the shaft, characterized in that the radial bearing (82) is designed in the form of a needle bearing (84). Furthermore, D2 relates to a surgical handpiece with a drive arranged in the housing and to an associated surgical drive system with a control and / or regulating device for controlling and / or regulating the drive.

[0014] US 2013 / 103067A1 discloses tissue removal devices comprising a hand housing, a motor, and a tissue removal mechanism connected to the hand housing. The tissue removal mechanism may include a tubular element, a rotatable elongated element arranged in a lumen of the tubular element, a first impeller distal to the rotatable elongated element, and a second impeller adjacent to the first impeller.

[0015] Further state of the art concerns the publications US 2005 / 245318 A1, DE 10 2010 017624 A1, US 2004 / 156744 A9 or WO 00 / 18521 A1, WO 2017 / 162786 A1 and WO 2006 / 094812 A1.

[0016] The aforementioned problems are solved, as disclosed, by the features of claim 1, which is limited to the nearest prior art, WO 2017 / 162786 A1.

[0017] 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.

[0018] According to the disclosure, the shaft section in the area of ​​the distal exit opening has at least a narrowed distal tip section.

[0019] The term "narrowed" or "constriction" 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.

[0020] 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 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.

[0021] 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.

[0022] According to the disclosure, the flow velocity of the cleaning fluid and thus the hydrodynamic cleaning effect are increased due to the distal narrowing of the flow cross-section.

[0023] Due to the design of the instrument handpiece according to the disclosure, during internal rinsing, a cleaning fluid is directed in a controlled flow direction from proximal to distal, all the way to the distal outlet opening. This prevents the fluid from flowing less effectively or ineffectively through the comparatively large opening of the inner ring of a distal ball bearing, which, as in the prior art, offers very little flow resistance. 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 pressure along the longitudinal axis of the instrument handpiece, which is sufficient for the cleaning effect and ideally even excessively high, as the main flow direction.

[0024] 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.

[0025] 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.

[0026] It is not relevant to the disclosure whether, in addition to the at least one narrowed distal tip section, further sections with a different cross-sectional area are encompassed 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.

[0027] Furthermore, it is not relevant within the meaning of the disclosure what type of connection or interface of the instrument handpiece, preferably located at the proximal end of the handle section, is designed for the external power supply, handling, or drive of the tool, which is preferably rotatably driven. Depending on the intended use and the desired tool speed, a hydraulic, pneumatic, and / or electric motor drive can be provided or operatively connected.

[0028] 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.

[0029] The dependent claims describe preferred embodiments of the invention.

[0030] However, for production-related reasons as well as from an application-related, especially fluid dynamic, point of view, radially constant or round cross-sectional areas or constrictions of the shaft section may often be preferred.

[0031] Therefore, from the latter perspective, 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 area of ​​the shaft section by a diameter ratio factor of at most 95 percent, preferably at most 85 percent, and more preferably by approximately 79 percent.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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 characteristic value problem in fluid dynamics – different or alternative absolute and / or relative dimensions must be chosen or are preferred.

[0039] 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.

[0040] 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.

[0041] This is particularly advantageous for effectively counteracting the problem, encountered in the prior art, of a reduction in rinsing 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 to the extent that, 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·v = V = const.; where A is the (internal) flow cross-sectional area; v is an (averaged) flow velocity of the cleaning fluid; and V is an (internal) volumetric flow rate of the cleaning fluid.According to the continuity equation for (incompressible) flow, this implies that the flow velocity (which correlates negatively with the flow cross-sectional area) decreases accordingly. Consequently, the flow term for the kinetic energy decreases (see Bernoulli's equation), which also results in a correspondingly unfavorable reduction in the mechanical cleaning effect in the prior art.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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 according to the flow condition known as the wall adhesion condition, especially in the case of pipe flow, and / or furthermore, for 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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. The annular gap cross-sectional area is thus calculated as the flow cross-sectional area by subtracting the areas of the two circles with the outer and inner diameters of the annular gap, respectively.

[0053] 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.

[0054] 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.

[0055] 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, more preferably less than or equal to approximately 3 mm², and particularly preferably less than or equal to 2.8 mm².

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] The increase in flow velocity, particularly the longitudinal vector component, through or along the inner rolling bearing can be measured or quantified in particular according to a respective associated bearing cage intensification factor: On the one hand, the respective associated bearing cage intensification factor, with regard to a primary or first bearing cage intensification factor, can be measured in comparison 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.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] Overall, the embodiment with the internal rolling bearing, preferably with the continuous bearing cage, offers advantages 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.

[0065] 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.

[0066] Preferably, the bearing cage is completely enclosed. This offers the advantage of maximum 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.

[0067] 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.

[0068] 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.

[0069] 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.

[0070] 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. Firstly, 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, orshort, long, etc., and / or according to hardness grades and / or 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 corresponding tool into the instrument handpiece.

[0071] 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).

[0072] 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.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] 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 characters

[0077] Fig. 1 is a slightly perspective side view of an instrument handpiece (without tool) in an embodiment according to the prior art; Fig. 2 is a side view of the instrument handpiece (without tool) in the embodiment according to the prior art; 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; Fig. 3b is, in accordance with the distal detail section of the Fig. 3a , a schematic representation of hydrodynamic streamlines, in particular illustrating the internal flow with a cleaning fluid; Fig. 4 is a slightly perspective side view of the instrument handpiece according to the disclosure (without tool) in a preferred embodiment; Fig. 5 is a side view of the instrument handpiece (without tool) according to the disclosure in the preferred embodiment; 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; Fig. 6b is, in accordance with the distal detail section of the Fig. 6a , 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 according to the preferred embodiment; 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 preferred embodiment; 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 towards a proximal rolling bearing, in the embodiment according to the prior art; Fig. 8b is one, to the first sectional view of the Fig. 8a distal, second sectional view of the instrument handpiece (without tool), showing the proximal rolling bearing in the shaft section, in the embodiment according to the prior art; Fig. 9 is a sectional view of the instrument handpiece as disclosed, showing a proximal area to the shaft section in the transition to a handle section; 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 Fig. 10b is one, to the first sectional view of the Fig. 10a distal, second sectional view of the instrument handpiece as disclosed (without tool), a central area of ​​the bearing cage as shown Fig. 7 pointing in the distal narrowed tip section, according to the preferred embodiment. Description of the exemplary embodiment

[0078] An embodiment of the present disclosure is described below, based on the associated Figuren 4 bis 6b , Fig. 7 , as well as Figuren 9 bis 10b described and thus an embodiment according to the state of the art in accordance with the Figuren 1 bis 3b as well as Figuren 8a und 8b This comparison reveals further details, characteristics, and advantages of the disclosure.

[0079] Insofar as the instrument handpiece according to the disclosure, according to the preferred embodiment, Figuren 4 bis 6b as well as the Figuren 10a und 10b the embodiment according to the prior art in accordance with the analogous Figuren 1 bis 3b as well as the analog Figuren 8a und 8b Since a differentiating feature as disclosed is not discussed, reference is made to the introductory description or the designations relating to the prior art in order to avoid repetition.

[0080] Fig. 1 or Fig. 2 Figure 1 shows a slightly perspective side view or a side view 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, which extends 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.

[0081] 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 unit, a drive unit, a power supply unit or similar, as known from the prior art.

[0082] 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 sections between them. The instrument handpiece 1 is usually grasped by the operator at the handle section 7 and manipulated during use.

[0083] The cylindrical shaft section 8 has a constant second diameter D2 (see Fig. 2 trained.

[0084] Furthermore, the Fig. 3a or 3b the same distal detail section of a lateral sectional view of the instrument handpiece (without tool) according to the state of the art: firstly ( Fig. 3a ) without flow in the sense of a conventional workshop drawing, and secondly in the manner of a hydrodynamic schematic representation in a fluid-flowing state ( Fig. 3b ). In Fig. 3b For the sake of clarity, only the streamlines S are marked with a reference symbol; therefore, in the following description, reference is made to the designation of the components with reference symbols in the associated document. Fig. 3a is referred.

[0085] These representations of Fig. 3a Figures 3b and 3b, in particular, reveal the entire internal rolling bearing. This is designed for the rotatable arrangement of a rotaryally driven tool (not shown) inside the instrument handpiece 1, specifically the shaft section 8. Therefore, the views of Fig. 3a or 3b 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 plurality of balls 30 as round rolling elements, which roll between a respective inner ring 26 and a respective outer ring 24, or rather, roll on 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.

[0086] Furthermore, this sectional view shows the Fig. 3a or 3b at the proximal end of the shaft section 8, an internal tool receptacle 19 for holding or anchoring the tool shaft (not shown) and a guide sleeve 32 are visible. The tool (not shown), inserted through the cylindrical bore 40 at the distal end of the tool, is preferably interchangeably held or coupled in the tool receptacle 19 and guide sleeve 32 of the instrument handpiece 1 and can be accessed via the proximal connection 5 (see Figuren 1 und 2 ) are driven rotaryally.

[0087] The hydrodynamic schematic representation of the Fig. 3b Figure 1 illustrates a fluid-flow state of the instrument handpiece 1 using linear streamlines S. Such a fluid-flow state occurs when the instrument handpiece 1 is inserted into a (not shown) rinsing device, 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 figure).

[0088] Regarding the flow through the entire rolling bearing assembly in the direction from the proximal ball bearing pair 22 (right in the image) to the distal ball bearing pair 20 (left in the image), this is determined by the course of the streamlines S of the Fig. 3b Clearly visible: Initially, a forced flow – and thus hydrodynamically effective cleaning – of the proximal ball bearing pair 22 occurs, due to the proximal design, as the flow surrounds the associated balls 30. However, upon exiting the proximal ball bearing pair 22, 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 or 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 permeated by the flow and thus not adequately cleaned (fluidically).

[0089] The flow path or flow conditions described above, from proximal to distal, through the instrument handpiece 1 in the embodiment according to the prior art, will be further detailed by reference to the Figuren 8a und 8b Illustrative. This shows Fig. 8a a first sectional view of the conventional instrument handpiece 1 (without tool), which shows a cross-section through the cylindrical shaft section 8 with a constant second diameter D2 (see also Fig. 2 ) concerns. The first sectional view of the Fig. 8a in an area of ​​the tool holder 19 (see also Fig. 3a ), which is arranged more proximal than the proximal rolling bearing 22 (Fig. 22). Furthermore, it shows Fig. 8b a second sectional view of the conventional instrument handpiece (without tool), which corresponds to the first sectional view of the Fig. 8a The second section view cuts distally, or further downstream in the direction of flow. Fig. 8b the proximal rolling bearing 22 in the shaft section 8 with the second diameter 8.

[0090] In the first and second sectional views (for the state of the art: in the Figuren 8a und 8b ) in particular the hydrodynamic schematic representation (for the state of the art: in the Fig. 3b ) Reference is made to the fluid flow state of the instrument handpiece 1, which is illustrated by the linearly drawn streamlines S (or an exemplary selection of the two streamlines from a real multitude).

[0091] The streamlines S emerge from a representation of the sectional view(s) (for the state of the art: in the Figuren 8a und 8b ) relative to the plane of the leaf; that is, (ideally) point-like in the direction of the viewer. Like, so to speak, the arrowhead of a corresponding flow vector of a flow velocity passing through the plane of the leaf, a respective (exemplary or selected) streamline S is represented as a point.

[0092] 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.

[0093] The first sectional view of the Figur 8a It can be seen 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, for flow through (with a point-like emerging streamline S). 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 with the annular gap inner diameter d-R2, respectively. For example, the annular gap cross-sectional area AR can be calculated as shown in Fig. 8a shown, 2.4 mm 2<.

[0094] The second sectional view of the Figur 8b The figure 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), as explained below: The proximal rolling bearing 22 is shown with 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, which is fitted into the shaft section 8 and also has an outer ring diameter d-26. Part of the flow passes (with a point-like emerging 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) according to a bore diameter dB (e.g. 2.4 mm).

[0095] Additionally, the other part of the flow passes through a rolling bearing interior of the proximal rolling bearing 22, formed between the inner ring 26 and the outer ring 24 and free of the (seven) balls 30, with a (free) rolling bearing cross-sectional area A-22 (e.g. 4.0 mm²) with two point-like emerging streamlines S.

[0096] 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.

[0097] In other words, the design of the conventional instrument handpiece 1 results in a disadvantageous situation: when cleaning fluid flows through it, the rolling bearing (or, as discussed here, the proximal rolling bearing 22, which is a representative example from a hydrodynamic perspective) is only subjected to a small, weak, or slow flow. A particularly disadvantageous aspect of the prior art is that the flow cross-section from the proximal end (the annular gap cross-sectional area AR, for example, 2.4 mm²) not only does not narrow but actually widens considerably distally (total rolling bearing flow cross-section, for example, 8.5 mm²). 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 proportional to the square of the flow velocity.

[0098] 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.

[0099] Based on the first and second sectional views for the conventional instrument handpiece in the Figuren 8a und 8b Thus, the above is based on the Fig. 3b The disadvantage already described from the state of the art is particularly evident, namely the insufficient (fluid) cleaning effect of the flow visualized by means of the streamlines S.

[0100] According to the present disclosure, this situation will be remedied. Figuren 4 bis 7 show different views according to an embodiment of an instrument handpiece as disclosed 1. Thus, show Fig. 4 or Fig. 5 [by analogy to] Fig. 1 or Fig. 2 [for the state of the art] a slightly perspective side view or a side view of the instrument handpiece according to the disclosure (without tool) in a preferred embodiment.

[0101] Unlike the prior art, the shaft section 8 has a different feature in the area of ​​the distal exit opening 40 (left in Figuren 4 bis 6b ) a narrowed distal tip section 10. The distal tip section 10 is narrowed from a second diameter D2 of the shaft section 8 down to a smaller first diameter D1 (see Fig. 5 In other words, the one that differs in the Figuren 4 bis 7 The preferred embodiment of an instrument handpiece shown differs from the conventional instrument handpiece according to the prior art, as described in the Figuren 1 bis 3b shown by the fact that the elongated shaft section 8 with a second diameter D2 in its distal area of ​​the cylinder bore 40 has a narrowed distal tip section 10 as a distal exit opening.

[0102] As in Fig. 4 Designated by means of curved brackets, 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, there is a circumferential step or sloping ramp as a transition area 11 (see Fig. 5 ) shaped with a gradual taper or beveled edge.

[0103] Furthermore, the Fig. 6a or 6b [by analogy to Fig. 3a or Fig. 3b for the prior art] each the same distal detail section of a lateral sectional view of the instrument handpiece according to the disclosure (without tool) in the preferred embodiment: firstly ( Fig. 6a ) uncirculated in the sense of a workshop drawing; on the other hand, fluid-circulated ( Fig. 6b ). In Fig. 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 symbol; therefore, in the following description, reference is made to the designation of the components with reference symbols in the associated table. Fig. 6a is referred.

[0104] These representations of Fig. 6a Figures 6b and 6b, in particular, reveal the entire internal rolling bearing. This bearing, designed for the rotatable arrangement of a rotary-driven tool (not shown), is located inside the instrument handpiece 1, specifically in the distal tip section 10 of the shaft section 8. The views of the [unclear text] are indicated by the dashed line (at the right edge of the image). Fig. 6a or 6b (as already mentioned in the) Fig. 3a or 3b) 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 on their respective circumferences. The respective needles 30 are rotatably enclosed or arranged about their longitudinal center axis in a plurality of associated longitudinal grooves 35 in the bearing cage 50. The distal needle roller bearing 20 and the proximal needle roller 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. Therefore, they roll or...The respective needles 30 of the distal needle bearing 20 and the proximal needle bearing 22 roll 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.

[0105] Fig. 6b shows how already the Fig. 3b For the state of the art, a schematic representation of hydrodynamic streamlines S. Thus, unless there are differences from the state of the art, to avoid repetition, reference is made to the explanations regarding Fig. 3b referred. In contrast to Fig. 3b illustrative Fig. 6b A fluid-flow state as described in the disclosure occurs when a cleaning fluid flows through the instrument handpiece as described (without the tool) according to the preferred embodiment. Such a fluid-flow state as described in the disclosure can preferably be brought about or set by inserting the instrument handpiece 1 as described into a rinsing device as described (not shown), such as a cleaning and disinfection device. The elongated streamlines S represent an 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 (from right to left in the image). The streamlines S thus 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.

[0106] Based on the course of the streamlines S of the Fig. 6b The flow pattern, as shown in the diagram, is clearly visible through the distal needle bearing 20 as a distal rolling bearing. Along almost 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 find a downstream path essentially towards the central axis of the shaft section. Thus, as shown in the diagram, a hydrodynamically effective (fluid) cleaning of the distal needle bearing 20 as a distal rolling bearing also takes place.

[0107] 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).

[0108] 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 guidance of the cleaning fluid. A small portion of the cleaning fluid also passes through the tool opening 40 as 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. Figuren 6a und 6b illustrate the constructive details regarding the installation or assembly of the bearing cage 50, which is located in Fig. 7 can be seen more closely as an individual component.

[0109] The technical effect on the course of the flow lines S due to the structural design and the arrangement of the particularly preferred embodiment with a bearing cage 50 is again particularly evident from the Fig. 6b This can be understood. It becomes apparent that the bearing cage 50 even causes a forced flow through the distal needle bearing 20, meaning that it is always passed through and thus (fluid) cleaned. In particular, the installation of such a bearing cage 50 also advantageously achieves a largely independent status from a proximally applied inlet pressure of the cleaning fluid, which further contributes to the stability of a cleaning process according to the disclosure.

[0110] Fig. 7 shows, in the form of an enlarged excerpt, with reference to Fig. 6a or 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 representation of the Fig. 7 It is clearly evident 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 each consist of five needles 30, which are uniformly distributed around the circumference of the bearing cage 50 and serve as non-spherical rolling elements. The needles 30 are rotatably arranged about their longitudinal axis in corresponding longitudinal grooves 35 of the bearing cage 50. Furthermore, a plurality of round guide elements 60 and a sliding surface 61 are visible at the proximal end of the bearing cage 50.

[0111] Fig. 9 shows a sectional view of the instrument handpiece 1 as disclosed, which shows a region proximal to the shaft section 8 in the transition 12 to a handle section 7 (according to Figur 4 ) represents. It can be seen that a cross-section of the Fig. 9 The associated (cylindrical) annular gap cross-sectional area AR (e.g. approx. 3.6 mm²) is formed 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).

[0112] Furthermore, they Fig. 10a or Fig. 10b [by analogy to] Fig. 8a or Fig. 8b [for the prior art] a first and a second side view of the instrument handpiece 1 according to the disclosure (without tool) in the preferred embodiment according to the Figuren 4 bis 7 : So, first of all, Fig. 10a a first sectional view in a bearing 22 proximal to the bearing (according to Figur 6a ) proximal area of ​​the tool holder 19 in the shank section 8 with the second diameter D2.

[0113] And further shows Fig. 10b one, to the first sectional view of the Fig. 10a distal, second sectional view of a central area of ​​the bearing cage 50 (according to Figuren 6a and 7 ) in the distal narrowed tip section 10 as revealed, with the first diameter D1.

[0114] Analogous to the above discussion for the state of the art (based on the relevant Figuren 8a und 8b ) is shown in the first and second sectional views of the Figuren 10a or 10b in particular the hydrodynamic schematic representation in the Fig. 6b Reference is made to the fluid flow state of the instrument handpiece 1, which is illustrated by the linearly drawn streamlines S (or an exemplary selection of the two streamlines from a real multitude).

[0115] Fig. 10a It can be seen that a cross-section of the shaft section 8 in Fig. 10a The associated (cylindrical) annular gap cross-sectional area AR (e.g. approx. 3.6 mm²) is formed 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).

[0116] It may therefore be particularly preferred that the cross-section of the shaft section 8 in Fig. 10a associated annular gap cross-sectional area AR of the cross-section of the Fig. 9 The associated (cylindrical) annular gap cross-sectional area AR corresponds approximately to (area ratio to each other of 90% to 110%, more preferably of 98% to 102%, in particular approximately 100%). This results in an advantageous uniformity of the course of the rinsing pressure, the flow rate, or the kinetic energy in the instrument handpiece 1 from proximal to distal.

[0117] Fig. 10b Regarding a distal cross-section as disclosed, with reference to Fig. 6a or Fig. 6b It can be seen that the distally narrowed tip section 10 with the first diameter D1 surrounds the cylindrical bearing cage 50, which extends longitudinally along the instrument handpiece 1, at internal distances. A corresponding 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.

[0118] Behind the one in Fig. 10b In the cross-section of the distal tip section 10 shown 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 (cf.Fig. 7 ).

[0119] 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).

[0120] Preferably, the bearing cage annular gap cross-sectional area A-50 can be less than or equal to 3.5 mm², more preferably less than or equal to approximately 3 mm², and particularly preferably less than or equal to 2.8 mm². Alternatively 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, such as in the Figures 10a and / or 9 shown. 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 (cf. Fig. 9 ) be.

[0121] In particular, according to the disclosure, the flow direction from proximal to distal at the distal outlet opening (with reference numeral 40, see Figures 4 to 6aThe rinsing pressure is positively increased in the bearing cage annular gap cross-sectional area A-50. Thus, the instrument handpiece as disclosed offers a remedy for the technically problematic situation in the prior art, which can occur in the form of a potentially insufficient rinsing pressure, particularly 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, pressure excess, or pressure delta compared to the atmospheric ambient pressure of, for example, approximately...950 mbar corresponds to a maximum (proximal) rinsing pressure of approximately 650 mbar for a single connected instrument handpiece. However, this maximum (proximal) rinsing pressure is divided among multiple instrument handpieces when they are connected, thus reducing the pressure for each. The exemplary cleaning and disinfection unit provides a maximum of 22 connections ("Luer-Lock: Miele type"; connection inner diameter 3 mm; therefore flow cross-section: A = approx. 7 mm²). With 11 connected instrument handpieces, i.e., half the number, a reduction in the respective (proximal) rinsing pressure to approximately 500 mbar was observed. With 22 (out of 22) connected instrument handpieces, the respective (proximal) rinsing pressure was further reduced to approximately 315 mbar.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 mm 2< ).

[0122] 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.

[0123] 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 sign

[0124] 1 Instrument handpiece 5 Connection 7 Grip section 8 Shank section 10 Distal tip section 11 Transition area 12 Profiling 19 Tool holder 20 Distal rolling bearing 22 Proximal rolling bearing 24 Outer ring 26 Inner ring 30 Rolling element 32 Longitudinal groove 33 Inner surface section 35 Guide sleeve 40 Distal exit opening 50 Bearing cage 60 Guide element 61 Sliding surface A Exit cross-sectional area A-B Bore cross-sectional area A-R Annular gap cross-sectional area A-22 Rolling bearing chamber cross-sectional area A-50 Bearing cage annular gap cross-sectional area D1 First diameter (of the distal tip section) D2 Second diameter (of the shank section) d-B Bore diameter d-24 Outer ring diameter (inner) d-26 Inner ring diameter (outer) d-33 Inner surface section diameter d-50 Bearing cage outer diameter d-R1 Annular gap outer diameter d-R2 Annular gap inner diameter L1 First length (of the distal tip section) L2 Second length (of the entire shaft section) S Streamline (cleaning fluid)

Claims

1. A surgical instrument handpiece (1) for a surgical instrument, comprising: - 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 the shaft section (8) is configured with a distal outlet opening (40) at the distal end of the shaft section (8) opposite the handle section (7), to allow a tool that can be replaced by a user to be replaceably arranged in the inner tool holder (19) by inserting it into the distal exit opening (40) of the shaft section (8), wherein the shaft section (8) has at least one narrowed distal tip section (10) with a reduced cross-sectional area in the region of the distal outlet opening (40), wherein wherein the shaft section (8) comprises an inner roller bearing configured to rotatably mount the replaceably arrangeable tool, preferably at least in part in the region of the narrowed distal tip section (10), wherein the roller bearing arrangement comprises at least one distal roller bearing (20) and at least one proximal roller bearing (22), and wherein the at least one distal roller bearing (20) and the at least one proximal roller bearing (22) are arranged in a spaced apart manner by means of a bearing cage (50) continuously formed between them, characterized in that the shaft section (8) is configured with an inner tool holder (19) at the other, proximal end of the shaft section.

2. The surgical instrument handpiece (1) according to claim 1, wherein a first diameter (D1) of the narrowed distal tip section (10): - is smaller in comparison with a second diameter (D2) of a non-narrowed region of the shaft section (8) by a diameter relation factor of a maximum of 95 percent, preferably of a maximum of 85 percent, further preferred of approximately 79 percent; and / or - amounts to between 3.5 and 5.3 millimeter, preferably to between 4.0 and 5.0 millimeter, further preferred to between 4.3 and 4.5 millimeter.

3. The surgical instrument handpiece (1) according to claim 1 or 2, wherein a first length (L1) of the distal tip section (10): - is of a length proportion in relation to an entire second length (L2) of the shaft section (8) of at least 5 percent, preferably of at least 20 percent, further preferred of at least 35 percent; and / or - amounts to between 5 and 40 millimeter, preferably to between 10 and 30 millimeter, further preferred to between 18 and 22 millimeter.

4. The surgical instrument handpiece (1) according to one of the preceding claims, wherein a transition region (11) designed as a shoulder from the narrowed distal tip section (10) to the non-narrowed region of the shaft section (8) is formed in a rounded shape and / or in a gradually tapering off shape and / or in a chamfered shape.

5. The surgical instrument handpiece (1) according to one of the preceding claims, wherein the bearing cage (50) is completely closed or is permeable to a fluid in a small area-related hole volume fraction, wherein the hole volume fraction preferably amounts to less than 40 percent, further preferred to less than 15 percent, particularly preferred to less than 8 percent.

6. The surgical instrument handpiece (1) according to one of the preceding claims, 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 inner roller bearing arrangement, comprise non-spherical rolling elements and are preferably formed as cylindrical roller bearings and / or as needle bearings.

7. The surgical instrument handpiece (1) according to one of the preceding claims, 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 inner roller bearing arrangement, comprise ceramic rolling elements.

8. The surgical instrument handpiece (1) according to one of the preceding claims, wherein a bearing cage ring gap cross-sectional area (A-50) of a ring gap arranged in the narrowed distal tip section (10), wherein said ring gap is formed at an outer lateral surface of the continuously formed bearing cage (50) between an inner surface section diameter (d-33) of the inner surface section (33) as a ring gap outer diameter and a bearing cage outer diameter (d-50) as a ring gap inner diameter: - amounts to less than or equal to 3.5 mm2, further preferred to less than or equal to approximately 3 mm2 and in particular preferred to less than or equal to 2.8 mm2, and / or - is less than or equal to a flow cross-sectional area through which a free through-flow is possible in a region of the instrument handpiece (1) being proximal thereto, and further preferred is less than or equal to a proximal shaft section ring gap cross-sectional area (A-R) of the shaft section (8).

9. A surgical instrument with an instrument handpiece (1) according to one of the preceding claims, and with a preferably rotatably driven and / or drivable tool.

10. A medical product set, preferably an application-oriented assortment for an operator like a surgeon, having at least one first instrument handpiece (1) according to one of the preceding claims directed to the instrument handpiece (1), in combination with at least: - one surgical instrument according to the directly preceding claim; and / or - with a plurality of different medical tools, in particular of rotatably driven and / or drivable medical tools, preferably in an assortment of the tools of different functions and types, and / or of a straight and / or curved shape and / or according to different sizes and / or hardness and / or materials; and / or - a second instrument handpiece (1) according to one 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 the insertion of a corresponding tool into the instrument handpiece (1).

11. A cleaning method for the internal flushing of an instrument handpiece (1) according to the invention according to one of the preceding claims directed to the instrument handpiece (1), in a flow direction from proximal to distal in a rinsing device.

12. The cleaning method according to the directly preceding claim for an instrument handpiece (1) of claims 5 to 9, characterized in that flow lines of a cleaning fluid running preferably through the proximal roller bearing (22) include such flow lines which run along the outer lateral surface of the continuously formed bearing cage (50) and / or through the at least one distal roller bearing (20).