Stand with a surgical microscope

The invention relates to a surgical microscope having a stand, wherein the microscope up to six degrees of freedom having and elements of the stand at the microscope suspension is attached, wherein the stand has two vertical Pivot axes subject to any influence by gravity are, and for height adjustment a parallelogram with weight compensation having that on smooth trained mobility and with brake for locking are.

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

is In another known microscope (US 5,332,181) the adjustment to all axis motorized instead. Given only a gross weight balance required, of course, is easier to produce than the fine balance the former arrangement. The problem with setting the microscope on a new task or new conditions is very slow through the engines because fast automatic Movements about the individual degrees of freedom to large Engines would require and particularly dangerous are. The surgeon must therefore wait a long time until the of he desired setting has been reached. This the advantage that only a rough balancing required is nullified.

For manual hands is a surgical microscope on a stand is a balancing always required. It is not just a counterbalancing by counterweights, springs and gas springs necessary, because the arms of the stand a certain weight have, of course, always has the same value. When adjustments of accessories of the microscope that in the execution be necessary operations, shifts but the focus on the microscope. It must then re Weight compensation be made about the rotational axis. The mechanical complexity with multiple axes of rotation is under consideration the necessary rigidity of the microscope suspension significantly and is increased by motor drives, if you enable the user the weight compensation want. There are even versions known (DE 4320443 A, DE 43 34 069 A), in which the weight compensation with sensors, Controllers and actuators automatically performed on demand will.

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

The inventive solution is that the microscope about a third vertical axis, which by no influence Gravity is subjected to a first additional perpendicular thereto Axis and a second further to the first further vertical axis is mounted on the stand, wherein the further Axes substantially perpendicular to the optical axis of the microscope objective are designed to be adjustable and motorized and the microscope further additional lateral axis Pivoting of the viewing direction (X-direction) and the permits between the third vertical axis, and the microscope nearby another axis disposed further axis pivoting the viewing direction forwards / backwards or up / down (Y-direction) allows.

Although it is known that mobility of surgical microscopes unlock to carrier units with buttons on handles, which are arranged at the microscope. Upon actuation the keys are electromotive brakes the swivel mounts dissolved. However, the invention is not exhausted that made movement around these axes quickly by hand can be, and then blocked the axes in this position can be. The invention is characterized by a rather Combination of adjustment by hand with a motor from setting.

The larger adjustment paths of the stand will be the user / operator counterbalanced in a conventional manner in so-called "free floating mode" enabled. He leads the device to a handle, for example. with an integrated button with which the movement can be released. It is made a fine counterbalancing the parallelogram been. This total weight compensation must precisely as possible be, so that only very small for the settings forces required are. An imbalance on the two directly existing on the microscope adjustment axes then does not bother, when provided with these axes a motorized adjustment is and the motors are strong enough, the corresponding Forces of imbalance record.

Due to the rotations about the third vertical axis, and two other axes, the surgeon can view the field adjust the requirements. The special order the other two axes is a very useful Adjustability for different operating conditions given. is the optical axis of the surgical microscope namely for different operations (eg. as brain surgery, Spinal surgery, eye operations) completely different aligned to the vertical. If one chooses the order the other axis different, so is this favorable Change the field of view no longer possible.

Conveniently, the motor drives the servo drives educated. done The default for this servo functions in a preferred manner of electrical force or torque sensors between the microscope and the operating element for the respective directions. The sensors are so adapted to a user with the operating element about an axis exerted torque increasing and at Write a direction change in the sign alternating signal. Conveniently, the control elements are adjustable so that the user adjust it in the most comfortable position for him can without thereby and the position of the sensors to the microscope thus changing the relation between the signals and the effective direction becomes.

In longitudinal and transverse forces and moments perpendicular to Sensor axis no signal is delivered. In a particularly zwechmäßigen embodiment, the sensors are paired so arranged that when a through by an operator exerted on the operating element force of a sensor is relieved, the other is loaded. Both sensors are with respect to the to be detected torque or to be detected the Force placed on either side of a neutral line. Both sensor elements are under pressure and are in a switched bridge circuit against each other, so that the signals by the pressure cancel each other out. Becomes a Moment or a force introduced into the control unit, or the rotation to cause this line tries increasing arises on one side of the neutral line Pressure, on the other hand falling pressure. correspondingly the bridge is detuned and delivers a the moment corresponding output signal. As sensors piezo elements, inductive sensors, capacitive transducers, resistive and optical power / displacement transducers are used.

The signals are further processed by control technology to make the adjustments on 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 are reduced the response times. While the user in the microscope for moving the four shared degrees of freedom adjusted, while acting which introduced to the direction setting of the microscope axis Moments on the control element and cause the servo controls the corresponding adjustment. The synchronous free adjustment of the microscope with major routes and Servo tracking of small angular motions of the deleted pure servo systems known effect that the user long must wait until the adjustment is completed.

Conveniently, the arrangement is such that the possible movements about the individual axes or degrees of freedom are limited so that the microscope is against parts can abut the stand.

The invention is described below with reference to advantageous embodiments with reference to the accompanying drawings described. Show it:<dl tsize="6"><dt>Fig. 1</dt><dd>the basic structure of the stand according to the invention 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 Fig. 2, the microscope, after it has rotated 90 °;</dd><dt>Fig. 5</dt><dd>in a similar representation as in Fig. 3 the microscope, after it has rotated 90 °; and</dd><dt>Fig. 6</dt><dd>the basic design of the sensors and electric Evaluation circuits.</dd></dl>

In Fig. 1, the arrangement of a surgical microscope is attached to a illustrated floor stand. The tripod stands on a Base or foot 101 for generally with rollers A method is provided. Of course, the base part 101 designed for ceiling or wall mounting be. On this base portion 101, a column 102 is mounted, about its axis A1 rotate the patch fixed arm 103 leaves. With about axis A2 rotary joint is it a parallelogram 105 is secured. The height adjustment of the Microscope port 108 on parallelogram 105 is at a Gas spring or a spring assembly 106 counter-balanced.

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

As shown in FIGS. 1-3, there is shown Microscope 111 with the servo drive 204 about the axis A5 rotate. This corresponds to a rotation in the visual field in the lateral Direction (X-direction). may together with the arm 110 the microscope 111 is rotated by the servo drive 206 about the axis A4 will. This corresponds to a movement in the visual field by up / down (Y-direction).

In Figs. 4 and 5 is the arrangement in a similar representation as shown in FIGS. 2 and 3, wherein the microscope 111 However, about the axis A4 is rotated 90 °, so that the objective axis horizontally is.

In Fig. 6 is shown schematically and by way of example, a force and torque sensor shown for the Y-adjustment. Between Bodies 401 and 402 is hooked an elastic plate 403rd Therein S1 and S2 are disposed two pressure sensors. If between the two bodies 401 and 402 to a moment M Action comes, you will in the elastic plate 403 reinforced on both sides of a neutral phase 404 and attenuated pressure forces which in the sensors S1 and S2 cause resistance changes. The further processing of the Signals are connected 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 for servo adjustment of the axis A4.

As mentioned, the movement about the axes A1, A2 and A3 as well as that of the parallelogram 105 smoothly, so that just made an adjustment can be. Locking then takes place by the brakes 120 instead, which are indicated by dashed lines in FIG. 1. These brakes can be solved for the rough adjustment by an corresponding key 113 is operated on the control element 115 becomes. The drive of the motors can be directly on the corresponding Axes act. However, it is also possible for a transmission interpose that indicated in FIG. 6 at 411 is.