Abstract: A surgical device primarily useful in arthroscopic acromioplasty surgery, the device, typically a pin, is formed to be temporarily implantable and fixable at a desired depth in one or more locations of the shoulder region. By the proper positioning of one or more of these pins a surgeon can visually identify the various shoulder anatomy, e.g., the acromion, the acromioclavicular joint, the clavicle and the associated ligaments and muscles, to determine the appropriate portion of the acromion to be resected. This allows the surgeon to avoid injuring the various ligments positioned contiguous to the acromior. The surgical device may also be formed with a visually observable measurement scale that can be positioned adjacent to that area of the acromion which is being resected to allow the surgeon to visually determine the extent of the resection.

Abstract: A packet communication system comprises a communication medium with two or more stations, each capable of transmitting and receiving packets of information. The system also has channel access means for providing sequential communication between stations; measuring means at each station for measuring the rate of flow of traffic on the communication medium; and control means, responsive to this measurement, for controlling the rate at which packets are admitted to the medium.

Abstract: Fast Fourier Transform methods of analyzing signal frequencies spectra yield results from zero frequencies upwards. Thus, when the frequency band of interest is not at very low frequencies a lot of wasted calculations may be performed, and resolution and computation time have to be traded-off against each other, often falling short of the requirements for both. A technique is described in which the signal to be analyzed is passed through an anti-alias filter and initial transform data is collected by undersampling. In a railway track circuit receiver which is to identify a predetermined carrier frequency or FSK signal, the anti-alias filter is selected to exclude frequencies other than those in a frequency band including the particular track signal so that there is no ambiguity in the calculated transform results.

Abstract: A method of manufacturing wafers of semiconductor material incorporates the steps of: providing an elongated ingot of semiconductor material having a curved surface along the direction of elongation; mounting a structure for ingot mounting on each of the end surfaces of the ingot; positioning the ingot mounting structures on fixture structures to mount the ingot; and rotating the mounted ingot. The positioned ingot mounting structures are released and the ingot is removed from the fixture structures; however, during the course of the process the mounting structures are again positioned on fixture structures to mount the ingot and the ingot is rotated a second time. The method is adapted for accurate centering of the ingot during processing involving the sawing of the ingot to provide opposed elongated planes therealong (including rotation of the ingot in accomplishing such) and involving further rotation of the ingot during grinding.