Abstract: An apparatus is provided for determining the concentration of an analyte present in a sample using multi-spectral analysis in the near-infrared (NIR) range. Incident radiation containing a plurality of distinct, nonoverlapping spectral regions of wavelengths in the near-infrared range is used to irradiate the sample. Diffusively reflected radiation emerging from the sample is detected, and a value indicative of the concentration of the analyte is obtained therefrom, preferably using an application of chemometrics techniques. Information obtained from each of the nonoverlapping spectral regions of wavelengths can be cross-correlated to remove background interference.

Abstract: An apparatus and method for aligning an end effector that is attached to a robotic arm of a disk certification system. The end effector includes a disk paddle that is pivotally connected to an end effector housing. The end effector housing has a center opening that can receive a gripper subassembly. The disk paddle grabs a disk which has a center opening. The disk paddle is aligned by placing the end effector onto an alignment plate so that a center alignment pin of the plate is inserted into the center opening of the housing, and an outer alignment pin is inserted into the center opening of the disk. The end effector has an adjustment screw that can be adjusted to vary the position of the disk paddle so that the outer alignment pin is accurately positioned within the disk center opening. After alignment the end effector can be attached to the robotic arm.

Abstract: A positioner which can move an object such as a magnetic recording head. The positioner includes a housing with an inner opening. The housing is located within a coordinate system that includes an x axis, a y axis and a z axis. An electrical/mechanical transducer is coupled to the inner opening of the housing by at least two flexure joint inserts. Expansion or contraction of the transducer creates a movement of the housing along the x or y axis. The flexure joint inserts allow the transducer to be adjusted within the inner opening during assembly to minimize the out of plane movement of the housing along the z axis.

Abstract: The present invention is a clock head assembly that provides reference clock signals during servo writing of a magnetic disk in a hard drive. The clock head assembly includes a clock head that is pivotably mounted to a housing. The housing encloses a disk mounted to a spindle. The spindle is attached to the spindle motor of a hard disk drive through an opening in the housing. The spindle motor of the disk drive rotates the spindle and disk of the clock head assembly. The clock head is coupled to a cam that is manually actuated by a lever to move the clock head arm assembly between a loaded position and an unloaded position. During servo writing, the clock head is loaded onto the disk so that reference clock signals may be read from the disk and provided to a servo controller which utilizes the clock signals to write servo information onto the disk within the hard disk drive. Upon completion of servo writing, the clock head assembly is detached from the hard disk drive.

Abstract: An apparatus and method for aligning an end effector that is attached to a robotic arm of a disk certification system. The end effector includes a disk paddle that is pivotally connected to an end effector housing. The end effector housing has a center opening that can receive a gripper subassembly. The disk paddle grabs a disk which has a center opening. The disk paddle is aligned by placing the end effector onto an alignment plate so that a center alignment pin of the plate is inserted into the center opening of the housing, and an outer alignment pin is inserted into the center opening of the disk. The end effector has an adjustment screw that can be adjusted to vary the position of the disk paddle so that the outer alignment pin is accurately positioned within the disk center opening. After alignment the end effector can be attached to the robotic arm.

Abstract: A method and device is provided for determining aortic valve abnormalities. The method first includes the step of providing a sphygmomanometer device for inducing a pressure on a body part of a patient. A data stream receiver is provided for receiving a stream of data relating to the pressure response of the pulsed fluid flowing through the cardiovascular system of the patient. A data processor is provided for processing the data to create a series of time dependant pulse wave forms. The data can be converted by Fast Fourier Transformation (FFT) to obtain Power Spectrum (PS) which comprises a frequency dependant array of pulse signals. Both of the time dependant and frequency dependant (Power Spectrum) data can be displayed and analyzed to help determine the condition of the aortic valve and the percentage of regurgitation of the patient.

Abstract: A detector for detecting a characteristic and a speed of a vehicle includes a first magnetic field sensor. The first magnetic field sensor includes a magnetically variable resistor that changes resistance in response to being exposed to a magnetic field. A bias is applied to the magnetically variable resistor and a change in the resistance thereof in response to an applied magnetic field is detected by an amplifier. The amplifier generates a first analog signal indicative of changes in the resistance of the magnetically variable resistor. A differentiating circuit differentiates the first analog signal and produces a first output that changes binary state in response to detecting a predetermined change in the differentiated first analog signal. A counter accumulates values at a predetermined rate and a microprocessor stores values of the counter corresponding to each change in the binary state of the first output of the differentiating circuit.

Abstract: A simple yet versatile noncontact optical inspection instrument and method are described for the inspection of magnetic disk surfaces for surface defects. This instrument is capable of inspecting the disk surface at any point in the disk manufacturing process. Surface defects such as bumps, pits and scratches can be measured. Surface contaminants such as particles and stains can also be measured. The instrument is also capable of discriminating between surface defects and surface contaminants. The instrument is comprised of two identical optical sensors which are located on opposite sides of the disk. A carriage supports and translates these sensors along the disk radius while a spindle rotates the disk. Both surfaces of the disk are therefore simultaneously scanned in a spiral fashion. The sensor's illumination optics produce a monochromatic focused spot of light which is normally incident upon the disk surface.

Abstract: A method of determining the distortion of an isolated pulse. Write data signals are recorded onto a magnetic storage media. Each write data signal includes a single transition that is relatively unaffected by adjacent transitions. Readback signals, each of which corresponds to a write data signal, are read from the magnetic storage media. The shape of the write data signals are measured. The difference between the shape of each write data signal and the shape of an ideal isolated pulse is measured.

Abstract: The invention measures the flow of a liquid by measuring the effect of that flow on a laser beam which travels from a laser source, through the flow, and landing upon a detector oriented to receive that laser source. Interfaces within the flow stream will refract the laser beam and cause variations in strength of the energy reaching the detector. These variations in the forward scatter occur at audio and super audio frequencies. The flow rate is proportional to audio frequency which can be measured and correlated by comparison to known flow rates.

Abstract: A rugged spindle for a disk certifier that test the disks of a hard disk drive. The spindle contains a first bearing and a second bearing that are coupled together by a shaft. The first bearing is coupled to a chuck that captures a disk. The second bearing is coupled to the spindle shaft of an electric motor which rotates the disk. The bearings each contain an outer graphite sheath that is separated from a hardened housing by an air bearing. The connecting shaft is bonded to the first and second bearings by an adhesive that is injected through longitudinal passages of the shaft. The bonding adhesive flows along the interface of the connecting shaft and bearings until the adhesive fills an indicator slot of the shaft. Air bearings are created during the bonding process of the second bearing to insure an accurate relationship between the two bearings and the housing.

Abstract: The present invention relates to an apparatus and method for amplifying a signal from a MR element of a hard disk drive magnetic recording head having a DC component and an AC component. The apparatus includes an amplifier circuit that amplifies the signal. An offset corrector circuit is coupled to the amplifier circuit and generates an offset signal representative of a complement of the dc component of the signal. A circuit is coupled to the amplifier circuit and the offset corrector circuit that combines the signal and the offset signal to provide an output signal representative of the AC component of the signal.

Abstract: The present invention relates to a method and apparatus for the measurement of defects in magnetic recording disks using a logarithmic amplifier. A magnetic head senses a magnetic field of a magnetic disk and creates a read signal having a varying amplitude. The test apparatus has a squarer which receives and squares the read signal. A logarithmic amplifier coupled to the squarer converts the squared signal to a logarithmic signal. The logarithmic signal is filtered by a first filter. A second filter coupled to the logarithmic amplifier provides an average of the peaks of the logarithmic signal. A digital-to-analog converter coupled to the second filter scales the output of the second filter. The test apparatus further comprises a comparator having a first input and a second input, where the first input is coupled to the first filter, and the second input is coupled to the digital-to-analog converter.

Abstract: A disk certifier which analyzes a read signal generated from a disk of a hard disk drive. The read signal typically has a sinusoidal waveform with modulated peak amplitudes. The waveform is generally defined by the equation A.multidot.sin(wt).multidot.(1-m(t)), where the term m(t) is the amplitude modulation of the signal. The peak signal is provided to a phase lock loop circuit which generates a multiplier peak signal generally of the form sin(wt). The certifier includes a multiplier which multiplies the read signal by the multiplier read signal to provide a multiplied read signal described by the equation A/2.multidot.(1-cos 2(wt)).multidot.(1-m(t)). The multiplied read signal is filtered by a low pass filter which has a cut-off frequency Wc below w. The low pass filter provides a filtered multiplied read signal which is described by the equation A.multidot.(1-g(t)), wherein the term g(t) is the portion of m(t) with frequencies below Wc.

Abstract: A method is disclosed for diagnosing, monitoring and treating cardiovascular pathologies. Among the hemodynamic parameters of interest are peripheral resistance, compliance, and cardiac (left ventricular) output. Peripheral resistance determined according to the present invention has been found to be a reliable indicator, not only of hypertension, but also of the cause of the hypertension. The determined peripheral resistance can be compared against a predetermined threshold value. This comparison helps to foster a diagnosis of a hypertensive condition.

Abstract: A headband ear protector apparatus including a pair of ear protectors and a resilient head band supporting, at opposite ends of the headband, the ear protectors. This forms a band which positions the ear protectors to lie by the opposite ears of a person. The headband is formed of a combination of hard and soft materials. The hard material is formed as a main support member for the ear protectors to extend between the ear protectors and provide resilience so the ear protectors will lie by the opposite ears of the person. The main support member includes at least one region having structure to receive the soft material to provide sound attenuation for reducing sound transmitted through the headband to the ear protectors.

Abstract: A test apparatus for testing a plurality of magnetic recording heads. The apparatus includes a tool which supports a bar that contains a number of individual magnetic recording heads. Alternatively, the tester may contain a tool which supports a plurality of individual sliders. The tool locates the heads within a magnetic field emanating from a coil wound magnet. The magnet has a length and permeability that provides a uniform magnetic field for each slider in the entire bar. The test apparatus includes a probe card that has a plurality of probe needles which make simultaneous contact with the bonding pads of each head. The needles are coupled to a test circuit that applies a constant current to the magnetic recording heads and measure a change in voltage as a function of a varying magnetic field. The tester can sequentially test the heads without spatially moving the bar, thereby minimizing the test cycle time of testing the heads. Alternatively, the tester may test two or more of the heads simultaneously.