Abstract: Apparatus for altering the output of an electronic string musical instrum responsive to bending of the string comprises a compressible electrically conductive member which has an electrical resistance which varies with the degree of compression applied and may be a conductive elastomer or a piezoresistive material. First and second holders are in contact with the conductive member and a current source is secured to the first holder and the string electrode secured to the second. Bending of the string causes the application of compression to the conductive member. The change in current flow is converted into an output which is a frequency variation which corresponds to the degree of bending of the string.

Abstract: Adaptive anisotropic digital filtering is automatically applied to the gray cale values of substantially of all the pixels in at least a portion of a digital image by, for each such pixel, selecting and angularly orienting the matrix of coefficients of an anisotropic filter kernel as a weighting function of the gray scale values of pixels in eight, 45 degree sectors under the kernel, and then performing a convolution of the gray scale values of pixels under the kernel with the rotated kernel to generate a filtered value for the center pixel. Local brightness of the image is adjusted either in conjunction with anisotropic filtering or separately by comparing for each pixel the average gray scale value of the pixels under the kernel with a reference value and applying a bias function to the center pixel grey scale value to brighten or darken the image dependent upon the results of the comparison.

Abstract: The invention shows a heart output and circulatory impedance measuring med and associated apparatus based on consecutive subtraction and synchronous summation of digitized ventriculographic images which effectively distinguishes between the motion resulting from contraction of the heart, and the motion resulting from actual displacement or physical movement of the heart back and forth within the chest cavity. From these data is computed a decrement in ventricular volume yielding, in time with subsequent images, the amount of blood ejected from the ventricle that represents the flow. By simultaneously recording the ventricular pressure and by synchronously dividing the pressure by the flow, ventricular load impedance is obtained.

Abstract: An electronic control device for providing control signals having direction and magnitude represented by electrical output signals based upon employing a circuit that senses relative changes in capacitance with a few volt excitation at suitable frequency. A finger touch unbalances the equilibrium between a pair of capacitance electrodes which by means of the circuitry selectively produces signals representative of magnitude and direction, and whose rate is proportional to the degree of unbalance, and which signals are used for vector control purposes. The electrodes are positioned in a recessed slot in an encasement, which slot is accessible by fingers, and which pair of capacitance electrodes is protected by a dielectric layer.

Abstract: An electronic stringed instrument which uses electrical resistance wires as strings to control the frequency of electrically generated sounds. By shorting a string at various points along its length a variable voltage output is obtained and converted into a known frequency. A fretted instrument provides a means to incrementally control the voltage output and a non-fretted type instrument with a conducting fingerboard can provide a means to variably control the voltage output. A separate current source may be provided for each string to faciliate chord playing and a control for the intensity and harmonic content of the signals is provided. An internal power supply and speaker may also be employed to make the instrument readily portable.

Abstract: An electronic stringed musical instrument having an electrically insulating fingerboard is disclosed. The fingerboard is provided with a number of segmented frets attached across its upper surface at desired points along its length. Each of the frets includes a number of electrically conducting fret segments each of which are electrically insulated from one another. Any number of strings may be provided on the instrument each string is disposed adjacent to and associated with a single fret segment of each of the segmented frets. A top-octave generator and octave dividers are utilized to selectively provide a fret segment of one of the frets with an electrical signal of at least one known referencing frequency. The strings are attached to the instrument in a spaced relationship with respect to the fret segments. Displacing a string to contact one of the fret segments completes an electrical circuit having at least one frequency equal to a frequency of the signal provided to that fret segment.

Abstract: A sound wave signal is applied to the nasal cavity and is picked up at the auditory canal of the ear of a subject. The phase difference between the two signals is a measure of the extent of opening of the Eustachian tube. By converting the two sound signals to electrical signals and transmitting them to a phase comparator it is possible to ascertain the changes in opening of the Eustachian tube during swallowing.

Abstract: A commissurotomy catheter and method for separating fused heart valve leaflets using the catheter is disclosed. The catheter is comprised of a lumen having at least two inflatable balloons at its operational end and at least one cutting edge between the balloons. To separate the fused leaflets the catheter is positioned within the heart so that it extends through the fused leaflets with a balloon on either side of the leaflets. Then the balloons are inflated which forces the cutting edge against the fissure between the fused leaflets and separates them. After separation the balloons are deflated and the catheter is removed.

Abstract: Apparatus for precise positioning of a movable stage such as a microscope stage including a light source and a self-scanning array of photodiodes for receiving light from the light source. An opaque shade is adapted to be moved with the shade and block at least a portion of the light which otherwise would impinge on the self-scanning photodiode array. The self-scanning photodiode array is adapted to emit an electrical signal proportional to the number of photodiodes on which light impinges. A digital comparator is adapted receive this signal in digitized form and compare the same with a positioning program digital input. In the event of a difference a responsive signal is emitted to a bi-directional motor drive which effects corrective movement of the stage. The apparatus may also function as a tachometer.

Abstract: An electronic stringed instrument which uses electrical resistance wires as strings to control the frequency of electrically generated sounds. By shorting a string at various points along its length a variable voltage output is obtained and converted into a known frequency. A fretted instrument provides a means to incrementally control the voltage output and a non-fretted type instrument with a conducting fingerboard can provide a means to variably control the voltage output. A separate current source may be provided for each string to facilitate chord playing and a control for the intensity and harmonic content of the signals is provided. An internal power supply and speaker may also be employed to make the instrument readily portable.

Abstract: A musical instrument is disclosed in which light beams striking a detector produce various tones and the loudness of the sounds produced is dependent upon the intensity of the light beam which can be changed by interrupting the beam or reflecting the light backwards to a detector situated next to the light source. A special amplifier circuit is provided which responds to both the amount of light beam interruption as well as the rapidity of interruption. The invention can be variously embodied in woodwind, string and percussion instruments and can also be used on a stage and controlled by moving dancers or musicians.