Patent Application
20060088370
The present invention relates to an improvement in a positioning device that will permit a user to position an object with one hand and to lock the positioning device in the desired orientation with his or her other hand. The positioning device disclosed herein has particular utility in surgical procedures where the positioning of a patient's head with respect to an operating table is required and includes a safety feature in the form of a locking mechanism to prevent accidental movement of a locking device and thereby the positioning device by a worker or attendant where the positioning device has been provided with the locking mechanism.
A number of devices have become available to assist surgeons in carrying out surgical procedures. Of particular interest to neurosurgeons are head restraining devices that maintain a patient's head in a selected position during an operation. Such devices are in use and are disclosed in my prior U.S. Pat. No. 4,964,748 granted Oct. 23, 1990 and U.S. Pat. No. 5,560,728 granted Oct. 1, 1996. In the devices disclosed in these patents, a plurality of relatively movable arms are provided each of which is equipped with a locking lever which has one end pivotally mounted on a rod carried in a bore provided in each arm. Each movable arm is provided with such a locking lever to lock each arm at one end to a shaft which extends through a bore at one or both ends of each movable arm and about which the respective arm is movable relative to the shaft. The clamping of the lever arm is actuated to close the bore of the arm against the surface of the shaft to frictionally engage the shaft and effectively prevent relative rotation between the shaft and the movable arm. Each arm of the device is similarly equipped. It is essential to the success of the operation that the locking levers that hold the arms of the device in relative fixed positions not be accidentally released as is possible where one of the attending individuals inadvertently takes hold of a locking lever thinking it is some other device connected with the operating table or other equipement. Also, it is important that quick adjustments be possible as necessary to move the relative position of the patient's head to carry out additional steps of the surgical procedure. Also, in surgeries, unforeseen emergencies may develop which require immediate movement of the patient's head such as to facilitate the stopping or prevention of bleeding. In such circumstances, speed of release and re-actuation and locking of the clamping arm or arms is important and could not be readily achieved with the locking lever of my prior patents or of any of the prior art devices presently available.
The present invention avoids the foregoing difficulty by providing a greatly simplified locking device for the locking lever of the arms of the head positioning apparatus. In one form, the locking device is a pushbutton operated detent pin which will allow the surgeon or an assistant to quickly either release or lock the arm without requiring visual observation of the apparatus and yet will prevent accidental release of the locking lever. Access to the locking device is achieved by virtue of the protrusion of the detent pin through the exposed surface of the locking lever. Locking of the locking lever in its closed position is also greatly facilitated by the use of a ball detent on a locking plate located adjacent to each movable arm. When the locking lever is moved to its closed position, one end of the pin will be shifted in a bore as the pin is pushed into the bore provided in the locking plate. The pin is a hollow sleeve and carries interiorly a rod which is provided with a peripheral recess. The bore in the locking plate includes a recess for receiving a portion of a ball that is carried by the hollow pin. Movement of the rod against a spring will control locking and release as described below. It will be understood that the bore in the locking plate may be provided with a number of detent type members but a ball detent is preferred. In this latter arrangement, captured balls are carried in openings near the end of a tube that itself carries the detent pin. The edges of the recess are shaped to force the balls between retracted, that is unlocked, positions, and projecting positions which effectively lock the lever arm in its closed position.
Referring now to the drawings, wherein like numerals designate corresponding parts throughout the views, there are shown, in
A table bracket 13 is employed to mount the apparatus 10 on a base such as the support for an operating table. The bracket 13 includes a shaft 18 to which is rotatably mounted one end of a positioning arm 14, which includes a bore through which the shaft 18 extends as shown in
As noted above, actuation, that is, locking and unlocking, of the locking levers 20, 20a and 20b, in my prior art devices, has been inconvenient at best and risky at worst, especially in emergency situations during a surgical procedure. To alleviate this, the present invention provides a modified locking lever 60 which, as shown in
More specifically, as shown in
It will be appreciated that other mechanisms may be employed to retain the pin 62 in the bore 80, but it is important that positive locking be provided to guard against accidental release of the locking lever 60. Also, as noted above, the other clamping arms 20 and 20a will preferably having locking levers provided with the locking device as described above in connection with locking lever 60. As described in my aforementioned U.S. Pat. No. 4,964,748, the locking lever 60 will function to restrain movement of a mounting pin 80 carried in the socket 52, and the operation of this portion of the lever arm 60 will be substantially the same as that described in the aforementioned patent.
Having described the invention, it will be understood that variations in the apparatus may be made without departing from the scope of the invention.
