Patent Application
20130140424
The invention relates to a stand, in particular to a stand for a surgical microscope.
During the procedure surgical microscopes are as a rule positioned above a patient, or the surgical area to be observed is located on the patient and the surgeon looks down from above, along the main axis, onto the surgical area. The surgical microscope is accordingly located at a relative spatial position between the patient and the surgeon. The particular features of the patient or of the surgical area, and the ergonomic needs of the surgeon, are thereby optimally taken into consideration. This purpose has already been served for some time, as a rule, by handles with which the surgeon can move the surgical microscope together with its microscope holder and the carrier arm. Once a desired position has been found, releasable brakes prevent involuntary lowering or upward pivoting (in the case of overcompensated counterweighting) of the surgical microscope out of the selected spatial position.
Conventional surgical stands having the above-described pivotability of the carrier arm relative to a pivot bearing bracket described, with the distal end of the carrier arm, a circular trajectory around their pivot shaft in the pivot bearing bracket, as is evident e.g. from FIG. 1 of DE 10042272 A1.
In the case of the stand indicated in DE10042272 A1, the microscope carrier (5, 8) is held as described above by a carrier arm (3, 6) embodied as a parallelogram carrier arm. As is clearly evident from the indicated
Further developments in the existing art have resulted in a solution to this problem. Early on, for example, stands operating according to the double-beam principle were created. Remaining with the example in
The surgical stands embodied in this fashion constitute the present-day standard for surgical microscopy. As indicated above, they permit a surgical microscope to be positioned more or less as desired in space, and the problems described above can be eliminated with these constructions; surgeons are thus able to make changes to the pivot position of the carrier arm without encountering the disadvantageous effects indicated above.
Disadvantageously, however, they require a certain skill in dealing with such surgical stands. Leaving that aside, stands of this kind constructed on the double-beam principle are extremely expensive.
Examples of such known constructions are found in U.S. Pat. No. 5,528,417 A and EP 628290 A1; these also indicate the manner in which microscope mounts held by parallelogram carrier arms of double-beam stands are to be held in a perpendicular position even upon pivoting of the parallelogram carrier arm. This occurs by way of a lever-like brace (crank member) on a vertical stand carrier arm, which is connected on the one hand via a tie rod to the microscope holder, and on the other hand to a non-pivotable stationary part of the surgical stand. This construction has already been disclosed previously in the art in the context of a wide variety of designs, for example in the design of light sources held in the manner of a beam balance for desk lamps, or the like.
If the surgeon does not possess the necessary skill or experience, however, and if the magnification set on the surgical microscope is perhaps also very high, then despite lever-like bracing, simply positioning the surgical microscope (in some cases only a little bit) higher causes the specimen or the surgical field to quickly escape away of the center of the observation field or entirely out of it. This can result in disorientation, and can require repositioning of the surgical microscope. This, however, leads to a loss of time during the procedure, which is not only undesirable but can also in fact be inherently disadvantageous in terms of the procedure.
The object of the present invention is thus to create a novel stand that avoids the problems indicated above, preferably without resorting to the double-beam principle and thus in economical fashion.
The novel stand is intended essentially to exhibit only slight technical modifications, however, so that a majority of the components used hitherto can be reused (including parts of stands according to the double-beam principle).
The stand is intended in particular to allow the surgeon to perform elevation adjustments on the surgical microscope without thereby necessarily displacing the main axis in space or with reference to a perpendicular.
The invention is usable regardless of the type of weight compensation for the load and in particular for the surgical microscope. The invention can be utilized both in stands constructed on the beam balance principle and with gas-spring-supported carrier arms.
The result of the fact that the carrier arm is variable in terms of its length as a function of the angular position, so that the microscope holder is variable in terms of its elevation along a perpendicular, is that the shifting effect on the surgical microscope caused by the arc effect is absent.
In the simplest embodiment, the carrier arm is embodied so it can be pulled out, so that once the brakes have been released, the surgeon pulls the surgical microscope forward (i.e. along an extension of the lengthwise axis of the carrier arm) simultaneously with raising it or, when lowering the surgical microscope (at most to a horizontal position of the carrier arm) shifts it simultaneously in the direction of the carrier arm so as to remain with the main axis along the same perpendicular or in the same position relative to that perpendicular.
This simple implementation of the invention has the disadvantage that once again a certain skillfulness is needed, in that the surgeon performs the change in the position of the surgical microscope with a certain sensitivity, or while continuously observing the surgical field through the surgical microscope and continuously readjusting the length of the carrier arm.
The invention is therefore further developed in this regard if the carrier arm (4) is variable in terms of its length automatically, i.e. in a manner coupled to the angular position (29). This is brought about, in particular and by way of example, by the fact that the carrier arm can be lengthened and shortened in motorized and sensor-controlled fashion.
A control system, which defines the length variation as a measured function of the pivot-angle position of the carrier arm, is preferably provided for this.
There are many possibilities for implementing the invention. For example, the carrier arm can comprise foldable angle elements that are displaceable in motorized fashion. The carrier arm can, however, also in particular be telescopically extendable, which makes possible not only an elegant appearance but also a space-saving implementation. Drives for telescopic length modification can be arranged outside or inside the carrier arm.
Integrated, telescopic constructions are preferred for the purpose of avoiding surfaces, which in any event need to be cleaned.
According to an embodiment of the invention, the stand is constructed so that the pivotable carrier arm is embodied as a single tier or single piece, and as an arm that is tubular or profile-shaped in section. This results in a slender, lightweight construction that leaves a great deal of space open for the surgeon and can be easily implemented.
A more stable variant of this is obtained if the pivotable carrier arm, as known per se, is embodied as two tiers or with multiple parts, preferably as a trapezoidal carrier arm; and that each of the carrier arm parts is embodied as an extendable arm that is tubular or profile-shaped in section, each of said carrier arm parts being extendable.
A construction of this kind is, as is known per se, realized as a rule with the aid of parallelogram carrier arms.
The underlying theory is that with a parallelogram support, the load that is acting can be correctly positioned and held without bending. It is found in practice, however, that even parallelogram supports are subject to a certain bending. This is influenced differently by the weight of the load, however. In the case of a surgical microscope, the load is a surgical microscope having a very wide variety of accessories. Because the different accessories generally entail a different weight loading, a difference in the deflection of the carrier arm structure of course occurs. This is particularly the case with a single-tier carrier arm but also, as already mentioned, with a parallelogram support.
A difference in bending because of a different load weight can thus results, even with the design according to the present invention, in a weight-dependent difference in the spatial positioning of the microscope holder, and thus in a weight-dependent spatial positioning of the surgical microscope.
This in turn results, when an accessory change occurs on the surgical microscope, in a displacement of its optical main axis with reference the surgical site. This in turn leads, in some circumstances, to a need for readjustment of the surgical microscope and/or of the stand, although this is undesirable during a surgical procedure for the reasons already indicated above.
According to a particular embodiment this disadvantage is at least partly compensated for by the fact that the carrier arm, or at least one of the carrier arm parts, is braced in weight-compensating fashion by a bracing spring with respect to the pivot bearing bracket or with respect to a vertical stand element or with respect to a vertical carrier arm. This spring can be arranged, as is usual per se with parallelogram supports, between the upper and the lower carrier arm part, but can also be located on the other side of the pivot bearing bracket in order to brace a carrier arm or carrier arm part that has been extended to that point. Reference is made to concurrently filed, co-pending, and commonly assigned application entitled “Stand,” bearing U.S. Ser. No. ______ and having internal reference number 033997.00187, claiming priority to German patent application number 10 2011 119 814.1 filed Dec. 1, 2011.
Alternative weight compensation systems, known per se, are likewise within the scope of the invention. Weight compensation systems entirely in beam-balance form, however, do not affect the aforementioned disadvantageous deflection.
In order to compensate fully for this, and to eliminate the deviation, associated therewith, of the main axis from its original location or from the perpendicular, provision is made according to a further development of the invention to ascertain the tilt of the stand holder or of the surgical microscope by means of measurement sensors, and to compensate for it by means of a positioning motor.
The apparatus for defining said angular position now no longer encompasses rods, bearings, and levers as is known and set forth above, but instead merely at least one motorized drive, in particular a positioning motor, that engages on the one hand on the carrier arm and on the other hand on the microscope holder, and in the context of operation defines the angular position between the microscope holder and the carrier arm in remotely controlled fashion and/or automatically. As a sensor, the particular desired one can be selected from the following non-exhaustive list of sensors: tilt sensor, height sensor, angle sensor, spatial coordinate sensor (e.g. IR sensor).
As a motorized drive for lengthwise displacement, and also for the first and/or the other positioning motor, at least one electrical drive can derive from the following non-exhaustive list of drives: electric motor, geared motor, linear motor, rotary stepping motor, electroactive polymers (EAP), pneumatic cylinder, electropneumatic drive, etc.
This improved construction according to the present invention achieves the further stated object regarding deflection compensation, which can play a relatively large role especially with supports or carrier arms elongated according to the present invention. This novel construction not only results in ideal angle compensation that is entirely independent of deflection and of the weight of the load or of the surgical microscope, and reacts consistently correctly to any pivot angle of the load arm, but also results in elimination of the hitherto considerable mechanical components.
This construction according to the present invention achieves the stated object. Not only does this novel construction result in ideal angle compensation that is entirely independent of deflection and the weight of the load or of the surgical microscope, and react in a consistently correct manner to any pivot angle of the load arm; it also results in elimination of the hitherto considerable mechanical components.
It thus results in a weight reduction, and also allows the parallelogram support, usual per se, to be replaced by simple tube or profile designs in which bending is deliberately accepted. The overall structure of the stand becomes lighter as a result, in particular also thanks to a reduction in the weight of balance weights, which of course become lighter when the carrier arm itself becomes lighter. The construction according to the present invention furthermore makes possible a more compact and improved design. It further reduces complexity in the context of draping (covering with a sterile protective film). Here again, reference is made to concurrently filed, co-pending, and commonly assigned application entitled “Stand,” bearing U.S. Ser. No ______ and having internal reference number 033997.00187, claiming priority to German patent application number 10 2011 119 814.1 filed Dec. 1, 2011.
According to a particular embodiment of the invention, such angle compensations can also be provided outside the pivot plane of the carrier arm, in particular orthogonally or transversely thereto. According to this particular embodiment, an additional drive is provided for such compensation measures. In a stand further developed in this fashion, the suspension system of the microscope holder can be spherical or can have two bearing axes arranged one above another and transversely to one another.
In order to ensure fail-safe operation, it is advantageous if the microscope holder is suspended with respect to the carrier arm in such a way that it automatically pivots or swings under its own weight, if the first and/or the other drive or motor is inactive, at least approximately into a stipulated angular position—in particular, close to the perpendicular—or is subject at least to a torque in the direction of that close-to-perpendicular position in order to reach that position.
Leaving aside any fail-safe operation, the result of an improved further development is that the microscope holder is suspended with respect to the carrier arm in such a way that its center of gravity is located to the side of a perpendicular through the suspension, in particular to the side of a pivot shaft and/or to the side of a rotation axis of the microscope holder, and in the operating state the first and/or the other drive or positioning motor automatically absorbs the resulting torque in order to pivot the microscope holding apparatus into the desired angular position, preferably into the perpendicular. What is achieved thereby is that the positioning motors are under less load or can require less energy consumption, and accordingly can also be physically small.
The configuration according to the present invention with angle-compensating positioning motors moreover advantageously allows the microscope holder to be suspended with respect to the carrier arm with a clearance that, in the operating state, is compensated for or set to zero clearance by the first and/or the other drive or positioning motor. This allows an economical embodiment of the bearings, while the precision of the surgical stand is nevertheless sufficient.
The construction according to the present invention is simplified if a control system is provided which defines the definition of the angular position(s) as a function of the pivot-angle position of the carrier arm. This control system need not obligatorily be an independent control system, for example a control chip directly in the region of the positioning motor(s); it can also be integrated, in hardware or software, into the computer that is normally present in the surgical stand or the surgical microscope.
Complete automation is made possible if a measurement apparatus, in particular a sensor, is provided, which, in the operating state, triggers the control system or the first positioning motor and/or the other positioning motor to define the angular position(s) as a function of the pivot-angle position of the carrier arm.
A sensor of this kind is preferably attached at the distal end of the carrier arm or on the microscope holder itself, in order to ascertain in situ the actual position of the carrier arm or of the microscope holder.
According to a further development of the invention, the drives for length modification and/or the first and/or the other positioning motor are embodied in self-locking fashion. The result of this is that unintentional displacement cannot occur in the currentless state, which contributes to safe operation. On the other hand, the self-locking feature can thereby act as a brake, so that in currentless mode the surgeon can overcome the self-locking by force and make any desired adjustments in that manner.
A variant of this construction results if the drive or the first and/or the other positioning motor is embodied in decouplable fashion in the manner of a releasable brake.
The further development of the invention results in any event in a device on the surgical stand for ensuring a continuously perpendicular position of the microscope carrier or of the microscope.
Another advantageous further development of the invention results if the carrier arm is telescopically extendable (see
This is achieved, for example, by the fact that a pivot motion out of the horizontal automatically results in an elongation of the carrier arm, in the same ratio at which the distance would be shortened by the pivoting. Reference is made in this regard to concurrently filed, co-pending, and commonly assigned application entitled “Stand,” bearing U.S. Ser. No. ______ and having internal reference number 033997.00187, claiming priority to German patent application number 10 2011 119 814.1 filed Dec. 1, 2011.
Further advantages, features, and details of the invention are evident from the description below, in which exemplifying embodiments of the invention are described with reference to the drawings. Features mentioned in the description may be essential to the invention each individually of themselves or in any combination.
The list of reference characters is a constituent of the disclosure. The Figures are described in continuous and overlapping fashion. Identical reference characters denote identical components. Reference characters having different indices indicate functionally identical or similar components.
It is critical and in accordance with the invention that when carrier arm 4f, 4g is angularly displaced upward in the direction of double arrow of angular position 29, the two parts of carrier arm 4f, 4g can be extended sufficiently far that main axis 27 of surgical microscope 28 remains in the same perpendicular, as in the position presently shown.
A bracing spring 20b supports the parallelogram and in that context acts in weight-compensating fashion on the load of the surgical microscope. Brakes (not shown) serve to define a specific pivot position of carrier arm 4f, 4g relative to its pivot bearing bracket 2a, which forms the distal part of a vertical carrier arm 30b of the surgical stand or stand body 42a. That part of the upper part of carrier arm 4f which projects to the left beyond its pivot bearing 46 carries as a balancing weight a symbolically depicted illumination device 50 that is shiftable in accordance with double arrow 51 on the part of carrier arm 4f (see also dot-dash position). The shiftability is preferably automatic and motorized, and is not depicted further. The shiftability offers a capability of influencing the balance that changes as a result of the elongation of the parts of carrier arm 4f, 4g.
This symbolic depiction can of course be replaced by any desired variants, in particular if a different illumination device is selected. Conventional shifting devices can effect the shift, and are therefore not discussed further.
The upper vertical carrier arm 30b is connected via a rotary bearing 52 to a lower vertical carrier arm 30a that stands on the floor via a stand foot.
The elongation capability of the parts of carrier arm 4f and 4g is achieved by way of one spindle each that connects a left and a right part of the partial carrier arms in motor-drivable fashion. As symbolically depicted, drive 44a, 44b for the spindles is located outside the parts of carrier arm 4f, 4g, and engages via a gear wheel or via a toothed belt or the like onto a respective threaded bushing 39 that is mounted axially nondisplaceably in the respective part of carrier arm 4f, 4g and receives a respective threaded spindle that is fastened in the respective second part of each part of carrier arm 4f, 4g rotatably but in axially lossproof fashion. When threaded bushing 39 is rotated, this results in a lengthwise displacement of the threaded spindle, and thereby in an expansion or contraction of a break point between the respective parts of the parts of carrier arm 4f, 4g. These parts are of course rail-mounted with respect to one another so that the partial carrier arms have a degree of freedom only in their lengthwise direction.
Further details of this construction may be gathered from DE 10042272 A1.
Even better visibility is provided, however, by the construction according to
At the distal end of bracing spring 20, it is fastened pivotably to an articulation flange 19.
Located at the distal end of carrier arm 4a is a microscope holder pivot shaft 15 that carries a microscope holder 6. The latter symbolically shows a rotation axis 8 for surgical microscope 28 that can be connected to a microscope interface 18 (
In order for surgical microscope 28 and its microscope holder 6 to be adjusted in terms of angle with respect to carrier arm 4a and/or with respect to the perpendicular, a first positioning motor 23 is provided which performs, via a right-angle drive train 14, tilt adjustment of microscope holder 6 relative to the perpendicular, or ensures the perpendicular position thereof. Angular position 21 is fundamentally not relevant but is nevertheless an indication of the desired setting.
As an alternative to this sensor 10, an angle sensor 45 could also be arranged around pivot arm bearing shaft 3, as depicted in
Carrier arm 4d, 4e is once again split in two in the construction according to
The following may be stated in summary: The invention relates to a stand and a surgical microscope 28 having a pivotable carrier arm 4. The latter is modifiable in length as a function of its pivot angle 29. It carries a microscope holder (6), pivotable in at least one plane, at the distal end of carrier arm 4, angular position 21; 24 of microscope holder 6 being definable with reference to carrier arm 4 according to a further development; and a motorized drive, which engages on the one hand on the carrier arm and on the other hand on microscope holder 6, and in the context of operation defines angular position 21; 24 in remotely controlled fashion and/or automatically. The construction facilitates utilization by a surgeon and ensures that he or she has an identically oriented view of the surgical field even after changes in the elevation of the surgical microscope (28).
Reference characters without indices denote, in this application, all identically named reference characters including their different indices.
The invention is not to be limited to the specific embodiments disclosed, and modifications and other embodiments are intended to be included within the scope of the invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 102011119813.3 | Dec 2011 | DE | national |
This application claims priority of German patent application number 10 2011 119 813.3 filed Dec. 1, 2011, the disclosure of which is incorporated by reference in its entirety. This application is also related to concurrently filed, co-pending, and commonly assigned application entitled “Stand,” bearing U.S. Ser. No. ______ and having internal reference number 033997.00187, claiming priority to German patent application number 10 2011 119 814.1 filed Dec. 1, 2011, the disclosures of which are hereby incorporated by reference in their entirety.
