Abstract: A network for use in a fourth generation CT scanner for noise reduction. The network comprises an active low pass filter whose cutoff frequency is controlled by a scaled signal responsive to the angular velocity of the rotating radiation source of the scanner. In a preferred embodiment a raw signal is generated by an encoder that detects movement of the source. As the source speed changes either in response to an operator's selection of a different scan speed or to systemic variations in the scanner relative to expected performance, the filter's cutoff frequency will automatically change thereby assuring optimum performance regardless of scan speed.

Abstract: Red cell samples are passed through a zone of focused illumination, and a scatter vs. time pulse is obtained for each. Each pulse is analyzed for pulse width, pulse area, and pulse shape. These parameters are respectively collected, and three coefficients of variation are obtained for each such collection. In addition to these three abnormality factors, the mean of the pulse shape collection constitutes a fourth. The four are respectively subject to statistical criteria, and are combined in predetermined fashion for a single red cell morphology index.

Abstract: Methods useful for differentiating and enumerating subpopulations of particles in a sample and more particularly relates to the enumeration of leukocyte subclasses. Enumeration is accomplished by utilizing two light scatter parameters and converting these parameters to a single parameter by employing a mathematical, nonlinear transformation.

Abstract: Real time acquisition of cardiac or other gated cyclical data using a scintillation camera with image formulation utilizing only such data that satisfied a preselected time frame for each cycle. The technique provides real time processing of gated data without the need for specialized hardware equipment or for post processing of the data. Unwanted information corresponding to cycles falling outside a preselected time frame are deleted in real time and hence do not contribute to the cumulative cardiac image.

Abstract: A method for correcting predictable errors in the location of detected scintillation events acquired during emission computed tomography by a rotational scintillation gamma camera system. The method includes calibrating the rotational scintillation camera system and generating a look-up table comprising a set of pairs of x and y offset values, one pair for each viewing angle. The calibration reflects systemic deviations in the location of the rotating camera head detector measured in terms of x and y coordinates in the frame of reference of the detector for a plurality of view angles relative to the geometric ideal expected path. Once a look-up table is generated for a camera system, the detected location of each gamma event is altered in real time by adjusting in the camera head the x,y coordinate location of each event by the x,y offset values previously generated for the corresponding viewing angle associated with the detected event.

Abstract: Methods for the determination of phagocytic and killing ability of selected leukocyte subclasses based upon the use of three part differentials obtained by light scatter characteristics and gated fluorescence. Particles having multiple fluorescent labels associated therewith, one of which is sensitive to reactive oxygen, incubated with the leukocytes. Detection of the fluorescent labels permits identification of cells having phagocytic ability, as determined by presence of the non-sensitive label, and also the identification of those with killing ability as determined by the decrease in fluorescence from the sensitive label.

Abstract: A diluted whole blood sample is hydrodynamically focused to a given point. A light beam is transversely focused on the same point and the principles of dark field microscopy are utilized, detecting scattered light and thereby discriminating platelets from red blood cells based on cell volume and refractivity.

Abstract: An all metal and ceramic high vacuum rotary anode X-ray tube adapted for mounting on a gantry of a rotational type CT scanner. The evacuated region where X-rays are generated is maintained at about 10.sup.-7 Torr. Vacuum sealing about the rotating shaft of the anode is provided by a magnetic fluid. No bearings are utilized within the evacuated region. Large, long wearing ball bearings that transmit rotation through the vacuum seal are provided about the shaft outside of the high vacuum region where conventional lubricants may be applied. Circulating coolant is applied internally through the anode assuring continual operation of the tube without the need for frequent cool-down waits.

Abstract: The patient's ECG signal is employed in a traverse-and-rotate type CT scanner as a time base for triggering the beginning of a traverse such that the traveling beam reaches the heart at a desired phase of the cardiac cycle. For a purely-rotational-type CT scanner, continuously generated scan data is only stored for corresponding phases of successive cardiac cycles. Alternatively, gating of the beams themselves can be controlled by the ECG signal. The use of a pacemaker to stabilize the cardiac period is described along with a system for recognizing unacceptable variations in the cardiac period. In a traverse-and-rotate-type fan-beam CT scanner, the effective beam width is narrowed to hasten the traverse of the heart.

Abstract: A system for monitoring patient respiration include a disposable, convenient moisture detection device. The device is minimally intrusive to the laminar flow of gases and has minimal liquid collection volumes. It is characterized by high sensitivity at rapid response rates.

Abstract: A blood pressure cuff is applied to the patient, pumped to a pressure above systolic, and then is reduced in pressure decrements. At each decrement, complexes are detected by investigating the signal slope, and peaks of the complexes are measured and compared. During the complex detection process, the signal slope is measured periodically at a rapid rate, and unless the slope meets predetermined criteria, the input filters are clamped to a baseline, and the process is repeated.

Abstract: A pressure cuff on the patient is inflated to a predetermined pressure above systolic, and then is deflated incrementally. At each decrement, oscillatory complexes are detected, and respective peaks are compared and evaluated as "true" complexes if they are within certain size matching criteria. After such "true" complexes are identified at a predetermined number of levels (e.g. 2 or 3), only a single complex is investigated at subsequent levels, provided specified size and timing criteria are met.

Abstract: In systems for rapid sequential analysis of fluid samples, such as blood samples, an electrochemical sensor is capable of equally rapid, sequential sample response by avoiding the need for equilibration during the measuring phase, and by substantially replacing the electrolyte acceptor for each sample. The sensor is made up of a pair of electrodes, an electrolyte acceptor, and a gas permeable membrane separating the electrolyte from the sample stream. Samples are passed rapidly by the membrane, and at the end of each such pass, the electrodes are polarized for a certain period, the flow of electrical current is measured, and the electrolyte is flushed and replaced by new electrolyte. This membrane material can be hydrophobic and also hydrophilic in nature.

Abstract: Method and apparatus for increasing the effective data storage transfer rate in a system to permit the recording of a rapid sequence of high resolution images by eliminating and hence not transferring designated portions of each image in the sequence.

Abstract: A beam deflecting assembly in a laser device for precision manual control of the point of impact of a laser beam on a selected target site. The assembly includes a pivotable joy-stick universally coupled to an angled manipulator arm which in turn is pivotably connected to a mirror mount in which a beam deflecting mirror is mounted. The mount is rotatable about a vertical axis and includes a yoke for pivoting the mirror about a horizontal axis. Deflection of the joy-stick in the horizontal direction results in rotation of the mount and, independently, deflection in the vertical axis results in pivoting the mirror mount about the horizontal axis. The components of the assembly are dimensioned such that a movement in the free end of the joy-stick is reflected in a corresponding displacement in angle and distance in the point of impact of the delivered laser beam on a selected target plane to give the operator of the laser device a sense of direct control of the beam.

Abstract: A hybrid collimator for tomographic imaging with a scintillation camera comprising a coded aperture plate and a parallel plate collimator. The code plate includes a plurality of lateral slits each of which is radiopaque or radiotransparent pursuant to a time modulated code. The parallel plates define a plurality of radiotransparent channels whose lengthwise orientation is orthogonal to the lateral slits of the code plate. In a preferred embodiment, the code plate is advanced across the channels of the collimator in a direction parallel to their lengthwise orientation rendering a time coded pattern that is identical for each channel.

Abstract: Automated blood pressure monitors utilizing a pressurized cuff are adapted automatically to work with a variety of cuff sizes, including neonatal. An acoustical pressure pulse is generated at the monitor, propagated to and through the cuff, and back to a pressure transducer in the monitor. The total time of propagation is indicative of the cuff size being utilized.

Abstract: Method for discriminating unstained cells from stained cells in a heterogeneous population. Specified cell types are stained with an absorbing stain and all cells are passed through the class of flow cytometry instrumentation employing focused collimated light sources. Detection of low angle and wide angle light scatter permits differentiation between the cell types on the basis that cells stained with an absorbing stain produce comparatively less low angle light scatter and comparatively more wide angle light scatter than do unstained cells.

Abstract: In a multifilamentary superconductor, plural filaments are separated from one another by a ductile nonsuperconducting copper matrix. The niobium titanium filaments are arrayed through the copper, with one filament being substantially larger than the others, and preferably, centrally located in the wire. Preferably also, the other filaments are arrayed in an annular configuration about the periphery of the wire.

Abstract: In the formation of a chemically sensitive field effect device, prior to formation of the gate membrane, an aluminum pad is disposed over the gate, and a polyimide layer is disposed thereover. Photoresist and etching steps produce openings in the polyimide to form a gridwork which is anchored to the device on the periphery of the gate. The aluminum layer is etched completely away, forming a void defined by the suspended polyimide mesh on one side, and the gate insulator on the other. Polymeric membrane is formed in the void by insertion in liquid form.