Stand with a surgical microscope

The invention relates to a surgical microscope with a stand, wherein the microscope as a whole has up to six degrees of freedom and is mounted on elements of the stand of the microscope suspension, wherein the stand has two vertical pivot axes which are subject to no influence by gravity, and for the height adjustment a parallelogram linkage with weight compensation, which are designed with smooth-running mobility and with brake for locking.

In such a tripod (US 5,213,293 A) the microscope can be brought into the desired position for the surgery with the help of the stand. It has a weight balance, so that it remains even in weak braked joints in this position. It is very complicated to effect this weight compensation. A subsequent adjustment of the microscope to change the image field must be carried out by hand.

In another known microscope (US 5,332,181), the adjustment takes place by motor about all axes. Given only a rough weight compensation is required, which is of course easier to effect when the fine balance of the former arrangement. The problem with the setting of the microscope to a new job or new conditions is very slow through the engines because rapid automatic movements about the individual degrees of freedom would require too large motors and in particular are also dangerous. The surgeon must therefore wait a long time until his desired setting has been reached. Thereby, the advantage that only a rough balancing is required nullified.

For manual handling of a surgical microscope on a stand a balancing is always required. It is not just a weight compensation by counterweights, springs and gas springs necessary because the arms of the tripod have a certain weight, which of course, always has the same value. If adjustments of accessories of the microscope, which are necessary for the execution of operations, but the focus shifts to the microscope. It must then be made about the rotation axes a rebound weight compensation. The mechanical complexity with multiple axes of rotation is considerably taking into account the necessary rigidity of the microscope suspension and is by motor drives even more if you want to enable the user the weight compensation. It is even possible embodiments known (DE 4,320,443 A, DE 43 34 069 A), in which the weight compensation with sensors, controllers and actuators are automatically carried out on demand.

It is a tripod 8 with a surgical microscope is known (EP 849 053 A), wherein the microscope 2 products having up to six degrees of freedom and is mounted on elements A1-A7 of the stand 8 on the microscope suspension, the two vertical pivot axes C1, C4, the no influence are subjected by gravity, and for height adjustment a parallelogram A3 having counterbalance, the microscope 2 is mounted on a third vertical axis C5, which is not subject to influence by gravity, and a first further axis perpendicular to C6 on the stand 8 wherein the further axis C6 is formed substantially perpendicular to the optical axis of the microscope objective and motorized adjustment and / permits a pivoting of the viewing direction forwards / backwards or upwards below. With this microscope, the axes are moved by motor by operating an operating handle.

The object of the invention is to provide a microscope with a stand, in which the adjustment of the location of the microscope can be made quickly by hand, then but a fine adjustment of the observable image field can be made without this manipulation caused by gravitational forces or by moments is disturbed.

The inventive solution is disclosed in claim. 1

The inventive solution is that the microscope in a third vertical axis which is not subject to influence by gravity, a first axis perpendicular thereto and a second further is mounted to the first further to the first further vertical axis of the stand, wherein the further axes are formed substantially perpendicular to the optical axis of the microscope objective and motorized adjustment and the microscope further another axis allowing a lateral pivoting of the viewing direction (X-direction) and arranged between the third vertical axis, and the microscope closer further axis further axis a pivoting of the allows viewing direction forwards / backwards or up / down (Y-direction).

Although it is known, unlock the mobility of surgical microscopes to support units with buttons on handles, which are arranged on the microscope. Pressing the keys electromotive brakes the swivel mounts can be solved. However, the invention is not exhausted by the fact that the movement can be made quickly by hand about these axes, and then the axes can be blocked in this position. The invention is characterized rather by a combination of adjustment by hand with a motorized adjustment.

The larger adjustment paths of the stand will be the user / operator in a conventional manner released counterbalanced in the "free floating mode". He leads the unit to a handle, for example. With an integrated button, with which the movement can be released. Here a fine weight balance has been made to the parallelogram. This total weight compensation must be as closely as possible, so that only very small forces are required for the settings. An imbalance on the two existing directly at the microscope adjustment axes then will not interfere when these axes a motorized adjustment is provided and the motors are strong enough to hold the corresponding forces of imbalance.

Due to the rotations about the third vertical axis, and the two further axes, the surgeon may adjust the field of view to the requirements. Due to the special order of the other two axes, a very convenient adjustability for different operation conditions is given. The optical axis of the surgical microscope is namely for different operations (eg. As brain surgery, spinal surgery, eye surgery) aligned completely different to the vertical. If we choose the order of the further axis different, so these favorable change the field of view is not possible.

Conveniently, the motor drives are designed as servo drives. The default for this servo functions carried out in a preferred manner of electrical force or torque sensors between the microscope and the operating element for the respective directions. The sensors are designed so that they give a user with the exerted on the control element about an axis torque increasing and changing change in direction sign signal. Conveniently, the control elements are adjustable so that the user can adjust in the most convenient for him able without causing the position of the sensors to the microscope and thus the relation between the signals and operating direction is changed.

In longitudinal and transverse forces and moments perpendicular to the sensor axis no signal is delivered. In a particularly zwechmäßigen embodiment, the sensors are arranged in pairs so that when the sensor is relieved by a force exerted by an operator on the control element force, the other is loaded. Both sensors are arranged with respect to the to be detected torque or the force to be detected on either side of a neutral line. Both sensor elements are under pressure and are mutually connected in a bridge circuit, so that the signals cancel each other by the pressure. When a torque or a force introduced into the control unit, the attempted, or the rotation to cause this line is created on one side of the neutral line increasing pressure, on the other hand falling pressure. Accordingly, the bridge is detuned and delivers an output signal corresponding to the moment. As sensors piezoelectric elements, inductive sensors, capacitive transducers, resistive and optical force / displacement transducers can be used.

The signals are processed by control technology to make the adjustments via the motor drivers and servo motors. With a sufficient dynamics of the two servo controls, together with the "free floating" the other four degrees of freedom, the adjustment times are reduced. While the user moves the microscope in the four shared the degrees of freedom, the same act which initiated the direction of setting the microscope axis moments on the control element and cause the servo controls the corresponding adjustment. The synchronous-free adjustment of the microscope with larger Because u nd the servo tracking of small rotations of the known pure servo systems effect that the user must wait until the adjustment is completed deleted.

Conveniently, the arrangement is such that the possible movements about the individual axes or degrees of freedom are limited so that the microscope can not abut against parts of the stand.

The invention is described below with reference to advantageous embodiments with reference to the accompanying drawings. Show it:<dl id="dl0001"><dt>Fig. 1</dt><dd>the basic structure of the invention Sta-tivs in a side view;</dd><dt>FIG. 2</dt><dd>the microscope in side view;</dd><dt>Fig. 3</dt><dd>the microscope in front view;</dd><dt>Fig. 4</dt><dd>. In a similar representation as in Figure 2, the microscope after it has rotated 90 °;</dd><dt>Fig. 5</dt><dd>. In a similar representation as in Figure 3 the microscope, after it has rotated 90 °; and</dd><dt>Fig. 6</dt><dd>the basic design of the sensors and electrical evaluation circuits.</dd></dl>

In Fig. 1, the arrangement of a surgical microscope is illustrated on a floor stand. The tripod stands on a base or foot 101 which is equipped with wheels for moving in general. Of course, 101 may be formed for ceiling or wall mounting the base part. On this base portion 101, a column 102 is attached to the patch fixed arm 103 leaves the axis A1 rotate. With about axis A2 rotary joint a parallelogram part is fastened with 105 axle 107th The height adjustment of the microscope port 108 on parallelogram 105 is counterbalanced with a gas spring or a spring assembly 106th

The microscope consists of a microscope body 111, the insight 112 and the lens 116 and is attached to the arms 110 and 109 rotatable about the axis A3 at the microscope connection of the stand. It can be moved free of the influence of gravity in mechanically predetermined space until frictional resistance with the rotations about the axes A1, A2 and A3 as well as the counter-balanced height adjustment with the parallelogram 105th

As shown in FIGS. 1-3, the microscope 111 shown therein is rotatably coupled to the servo drive 204 about the axis A5. This corresponds to a rotation in the field of view in the lateral direction (X-direction). Together with the arm 110, the microscope 111 can be rotated by the servo drive 206 about the axis A4. This corresponds to a movement in the field of view up / down (Y-direction).

In Figs. 4 and 5 is the arrangement in a similar representation as in Figs. 2 and 3, wherein the microscope is, however, 111 is rotated about the axis A4 by 90 °, so that the lens axis is horizontal.

In FIG. 6 shows schematically and exemplarily a force and torque sensor is shown for the Y-adjustment. Between the bodies 401 and 402, an elastic plate 403 is hooked. Therein S1 and S2 are disposed two pressure sensors. When 401 and 402, a moment M comes into effect between the two bodies, as arise in the elastic plate 403 on the two sides of a neutral phase 404 increased and attenuated pressure forces that cause S1 and S2 changes in resistance in the sensors. The further processing of the signals to the bridge circuit 405, the amplifier 406, the analog / digital converter 407, control engineering processing 408 and a driver 409 for the stepper motor 410 to servo control the axis A4.

As mentioned, the motion about the axes A1, A2 and A3 as well as that of the parallelogram 105 is smooth, so that easy adjustment can be made. Locking then takes place by the brakes 120, which are indicated by dashed lines in FIG. 1. These brakes can be released for the coarse adjustment by a corresponding button 113 is pressed on the control element 115th The drive of the motors can act directly on the respective axes. However, it is also possible to interpose a transmission.