Abstract: An apparatus for determining hematocrit, white cell and differential white cell and platelet counts in a centrifuged sample of blood contained in a transparent tube, preferably of capillary size. The apparatus is manually operated and utilizes a card which is appropriately calibrated on which the various blood cell counts are recorded.

Abstract: A portable blood pressure recorder device for an ambulatory subject having an inflatable occluding cuff, a pump for inflating the cuff, a sensor for detecting Korotkoff sounds, a transducer for detecting pressure in the cuff, a variable voltage reference and signal circuitry system for encoding a pressure signal from the transducer into pressure segments, a recording system for combining the Korotkoff sounds with the encoded pressure segments, circuitry for activating and deactivating components of the device, and a data retrieval system for interpreting recorded data.

Abstract: An improved electroencephalograph system is disclosed having a system for automatically verifying the input and output parameters of the various channels, the preset number selected, and a patient identification number. A coded output is used employing the standard EEG pen recorder outputs. Numerical sequences such as the preset number and a patient identification number are displayed on a single event marker channel as modified Roman numeral sequence of digits directly readable by the operator.

Abstract: Apparatus is disclosed for long-term ambulatory monitoring of blood pressure by an auscultation method, employing a pressurizable cuff and requiring no intervention by the patient. Heartbeats are sensed by ECG electrodes, and a microphone is used to sense the Korotkow sounds as the pressure in the cuff is varied. The presence or absence of a Korotkow sound within a preset interval following each heartbeat is used in determining when the cuff pressure equals the systolic and diastolic pressures. Those pressures are determined in each cycle of operation and are recorded on a continuously-running portable tape recorder, along with the ECG signals. In each cycle of operation, the initial pressure to which the cuff is inflated is based on the systolic pressure measured in the immediately preceding cycle. The pressure in the inflated cuff is thereafter stepped downward in small discrete decrements triggered by successive heartbeats during the measurement phase of each cycle.

Abstract: A method and apparatus for processing and displaying ECG waveforms and the like is comprised of a playback circuit to demodulate FM and digital signals for transcription on an endless paper loop in a series of straight lines or traces. A paper loop drive unit is capable of handling and advancing the endless loop continuously past one or more scribing pens which are offset in succession to produce a predetermined number of traces in parallel rows across the length of the loop with time segment markings closely correlated with the information recorded.

Abstract: A number of measuring electrodes for emplacement on the head of a patient, signal amplifiers whose input channels are connectable, via a selector, to the measuring electrodes according to a pattern selection program, and recorders controlled by the output signals of the signal amplifiers. The selector manifests, in a head-image area, one electrode switch for each measuring electrode, by means of which electrode switch the measuring electrode is connectable to an input channel, and which electrode switch is arranged in a position relative to the head-image area corresponding to the application location of the measuring electrode.

Abstract: A system for encoding, recording, playing back, decoding, validating, and displaying cardiac signals obtained from a patient during ambulatory monitoring. The system permits the recording on a single track in a magnetic tape of a channel of ECG signals interrupted intermittently by blood pressure signals, time of day signals, and event marker signals. The ECG signal is recorded in analog form, but the other signals are recorded as pulse coded signals each having its own format. In the playback apparatus, decoders identify and verify each of the signals when they occur, and the played back information is plotted on a chart. If the time of day signal was not recorded on the tape, timing information can be produced by the playback apparatus from the cumulative tape travel. Fiducial signals introduced in the recording, playback, and charting operations are used in a method for identification and measurement of recording tape speed error, playback tape error, and plotter speed error.

Abstract: An electrocardiograph for recording electrocardiograms on fan-folded paper, comprising a manually operable derivation selection switch and a motor control member for the paper transport motor. The paper transport is automatically stopped when the recording stylus has passed an adjustable number of folds in the fan-folded paper.

Abstract: A recording device using a portable recorder, such as a small, battery powered tape recorder, carried on the person and provided with electrodes for attachment to the body of the user, the electrodes being operable to sense cardiac activity and to provide the input signals to a program module coupled with the recorder to cause the latter to be turned on and off at predetermined times so that it operates at predetermined periods for the purpose of recording samples of the user's cardiac activity sensed by the electrodes. The program module operates to amplify the input signals from the electrodes and to cause these signals to modulate a carrier wave signal suitable for recording by the tape or other recorder. The program module also is operable to demodulate the carrier wave signal when it is played back from the recorder to reproduce an accurate reproduction of the input signals from the electrodes.

Abstract: A device for automatically timing and recording the sedimentation rate of fluid samples contained in cylindrical, transparent test tubes includes a generally rectangular rack having flat vertical walls formed with cylindrical bores for receiving the test tubes, and vertical channels at outer sides of the walls for receiving photographic strips. A lamp inside the rack shines through test tubes to the strips to record the amount of sedimentation of the fluid. The walls of the rack may be transparent for passing light therethrough or may be provided with slits at inner sides thereof for communicating with the bores. The bores communicate with the channels via other slits formed at outer sides of the bores. A rectangular housing may be fitted over the rack to exclude ambient light.

Abstract: An electronic sphygmo-manometer utilizes a sleeve, which is wound around the patient's arm for taking pulse pressure values. The sleeve is equipped with a sound transducer connected to the pressure gauge. The point of the pressure gauge is deflectable perpendicular to the rotation plane and the needle tip can be brought into contact with a record card beneath the needle by means of an electro magnet. If the electro magnet is activated by a power circuit, which is controlled by an electrical signal created from the Korotkoff noise, the needle tip is pressed against the record card and produces an imprint on the record card. By sweeping the pressure from a value above the systolic pressure to a value below the diastolic pressure, a card is obtained with imprints covering the pressure range from the systolic to the diastolic value. The instrument is easily to be operated and provides for a high accuracy combined with low susceptibility to noise.

Abstract: A system for detecting, quantizing, and displaying simultaneously on a single recording a wide panorama of cardiac diagnostic information including data inputs from EKG, phono-doppler, sound, and pulse; displaying each input in a distinctive color or form, in coordinates of time, frequency, and amplitude. A multi-channel recording system with an "instant replay" feature is employed to record simultaneously the respective inputs plus a timing pulse in separate channels, the timing pulse being generated by the periodic recurrence of a characteristic signal present in one of said inputs. A given sequence is selected for analysis and the recorded inputs for that sequence are replayed and fed to a high speed digital voltmeter-computer combination which dissects the wave form of the signals of each of said inputs separately and provides a read-out of the entire time, frequency, and amplitude content of all portions of the wave form of each input.

Abstract: The broadband auditory thresholds of marine mammals are determined by an apparatus which compensates for the animals' movement artifact. A number of evoked responses to audio stimuli are average during discrete time intervals. This approach reduces the effects of potentials attributed to movements of the animal, for example, the opening and closing of the blow hole. A threshold detector circuit, a tape delay and related circuitry electronically cooperate to block potentials attributed to the movement artifact when the potentials exceed the likely magnitude of the evoked response. Optionally, an oscilloscope is used to provide a visual representation of the evoked response and the potentials are manually inhibited when the movement artifact masks or otherwise overrides the evoked response.

Abstract: An electrocardioscope with an input amplifier amplifying the analog ECG signals, with an output Y-amplifier for the Y-deflection and an X-output amplifier for the X-deflection. Between the input amplifier and the output Y-amplifier an analog digital converter, a memory with N-addresses and M-memory values per address and a digital analog counter are arranged. The address selection is determined at the memory by an address generator with N-sites. The input of the output X-amplifier is connected with the digital analog converter and the input of the latter is connected with an X-counter with selectively settable N- and N+n-count digits and the address generator and the X-counter are clocked by a clock.

Abstract: Pulse motors rotating at periods corresponding to physical rhythm, rhythm of sentiment and rhythm of intellect are provided and discs having a pin eccentrically extending are coupled, respectively, with output axes of pulse motors so as to convert rotation movement into reciprocation movement through T-shaped piston rods. Plungers having ball point pens are respectively provided on the T-shaped piston rods. Data put in by digital switches are stored and calculated by the guide number to determine rotation angle of the pulse motors to set the ball point pens at the starting position. At the first recording area for the first date of a month arriving below the ball point pen, the pulse motors are initiated in their rotation from the starting position within a proper period thereof and a coil is energized so that the ball point pen will come in contact with the recording paper for drawing up the biorhythm chart.

Abstract: A system for the cyclical time-compression of a signal waveform, particularly applicable to displays. Continuous input data is temporarily stored, as in a recirculating memory, during the trace and retrace phases (B & A) of a processing or display operation. The stored data is subsequently read out in time-compressed form during the trace phase (B) of the cycle. The average rate at which data is read out of storage is faster than the average rate at which it is entered, the ratio of average readout rate to average entry rate being the compression ratio of the system and corresponding herein with the ratio of a full display sweep cycle to the trace portion of that cycle such that the initial waveform, time-compressed, is displayed in its entirety. In an illustrated embodiment, the data is entered into a recirculating memory at a rate resulting in apparent precession of the data in memory.

Abstract: Apparatus for generating and recording signals from two separate sensors on a patient adapted to provide an indication of the condition of an anatomical member to be monitored.A control cabinet having an integral strip chart recorder is provided with plug in inputs for two externally connected strain gauges. Each strain gauge makes up one leg of a bridge circuit. The bridge outputs are amplified and multiplexed into a single channel strip chart recorder having a single, heated stylus which records two separate traces based on the signals received from the two sensors.Heat to the recordinng pen or stylus is turned off during switching excursions of the pen between the two traces so as to eliminate shading and marking which would otherwise occur on the recording chart between the traces at slow chart speeds.

Abstract: A system for the enhanced display of event markers in time-related association with physiological waveforms displayed on cathode ray tubes which use a recirculating memory to provide a refreshed display. The event is marked in the displayed waveform by an intensification of the normal trace determined by the time-related occurrence of the event and comprises a first modulation of the displayed waveform. A secondary event-controlled modulation of the primary modulated display serves to further enhance and accurately identify the occurrence and timing of the event marker in the display. This enhanced display of event markers is further utilized to distinguish a marker of one type from a marker of another type utilizing particular data coding in the memory and appropriate detection logic for recovering data from memory. The enhanced display is particularly useful for clearly marking events occurring in timed-relationship with a patient's cardiac cycle.

Abstract: A method and means for graphically recording electrocardiographic data reduces the amount of redundant data displayed so as to reduce the size of the electrocardiogram. However, arrhythmias and other aberrant ekg signal complexes are reproduced in context for diagnostic purposes. Typical or normal signal complexes received from the patient are used to establish an ekg signal complex pattern. In the absence of aberrant signal complexes, this pattern is recorded in lieu of the patient data at a speed which is less than the normal recording speed to form the electrocardiogram. One such pattern may be recorded for every 25 complexes in the patient data, thereby achieving the reduction in the size of electrocardiogram. When an aberrant signal complex occurs, it is entered in the electrocardiogram at the normal higher recording speed. For repetitiously occurring aberrant signal complexes, only certain occurrences of such aberrancies are entered in the electrocardiogram.

Abstract: A data plotter for use in a multi-channel chart recorder operable to record time-variant analog scalar components of vector data signals on a moving recording medium. The data plotter comprises stationary printing means, preferably a thermal print head, for plotting vectors and other data derived from sampled scalar components as an aid in the interpretation of their analog traces.

Abstract: An improved graphical recorder display system for obtaining an accurate record of one or more sensed and displayed parameter values, such as associated with one or more vital signs of a patient.

Abstract: An electroencephalograph (EEG) instrument or system including a visual display panel actuated in response to digital signals for indicating the particular pattern in which the electrodes connected to the patient are processed to provide the desired output signals.

Abstract: A portable medical data strip chart recorder in which a drive roller for drawing the strip across a platen includes integral motive means for rotating the roller at a selected angular velocity. A D.C. motor is mounted internally and concentrically with the roller shaft which upon energization drives the roller and hence the strip paper at a desired linear velocity. The incorporation of a D.C. motor internally of the drive shaft permits reduction in size and weight of the recorder as well as achieving a more efficient drive power transmission.

Abstract: A system for sensing and recording items of medical information relating to the human body includes a plurality of sensing devices responsive to various parameters associated with the human body for producing data signals determined by the sensed parameters, a code generator for producing different code signals indicative of the various parameters to be sensed, and a recorder for recording the code signals and data signals in a predetermined relationship on a recording medium. The system is embodied as an insurance data collection system for automatically measuring and recording such characteristics of the human body as height, weight, girth (waist and chest expansion), blood pressure and electrocardiogram test results on a magnetic tape cassette. In addition, an input arrangement is provided to allow the results of an independent test, e.g., a urine examination, to be recorded on the cassette.

Abstract: A sphygpressure graph of the aneroid gauge type including a housing, connected with a sphygmocuff, supporting a series of telescoping tubes, connected in right angular relation, and a stylus, mounted on the endmost tube, movable over a chart to scribe the blood pressures. A ratchet and pawl arrangement engaging the telescoping tubes prevents reciprocating action of pulse pressure moving the stylus in a to and fro movement transversely over a graph paper but records the pulse by longitudinally scribing a graph paper during release of pressure from the sphygmocuff.

Abstract: A multispeed ECG magnetic tape scanning device for processing and observing in a relatively short interval of time large quantities of ECG signals from two pairs of ECG leads. The information from the two pairs of leads is provided simultaneously on a single oscilloscope tube as one trace above the other, either in real time or at a high speed multiple as a superimposed ECG presentation, or superimposed on each other so as to provide superimposition of the already superimposed ECG signals. An arrhythmia bar graph is also represented on the CRT tube. The playback is in real time, or at multiple high speed playback speeds of 30, 60 and 120 times real time. The playback amplifiers have specific amplitude and frequency responses which are logically switched upon the selection of a particular playback speed to provide accuracy in the reproduced ECG information.

Abstract: Apparatus for placing identifying indicia on x-ray film within a cassette, in which an electroluminescent panel is provided with a resiliently biased slide element movably mounted on a cassette supporting member. A printing unit applies time and data information to an indicia bearing card and simultaneously activates a control circuit for a predetermined time interval to condition the circuit for the energization of the panel only during this interval. The thus imprinted card is then placed on the panel, and as the cassette is positioned on the supporting member a portion of the panel protrudes into a slot-shaped opening in one edge of the cassette. When the cassette reaches its proper position on the support member, the control circuit is effective to illuminate the panel and thereby expose the film with the information on the card.

Abstract: This apparatus provides a stamp time indication of when a medical or scientific specimen container is made available for use and a second time stamp indication of when the specimen container is rendered unusable, thereby providing a time indication of when the specimen was collected or the specimen container was otherwise utilized.

Abstract: An apparatus for detecting breathing abnormalities forms a visual display of the breath sounds of a patient using a time-expanded scale on the order of meters per second to thereby delineate the differentiating sonic characteristics of these sounds. Breathing abnormalities such as coarse and fine rales, which are normally difficult to distinguish from each other, as well as abnormalities such as rhonchi are readily perceived and distinguished, and early diagnosis of diseases such as bronchities and bronchial pneumonia may thereby be facilitated.

Abstract: An electrocardiogram (EKG) data strip is constructed with contiguous, repetitive segments to allow individual heart lead tracings recorded on the segments to be readily removed from the EKG data strip after the tracings have been completed so that the segments can then be inserted directly into a permanent record form.The EKG data strip of the present invention has a first longitudinal line of perforations along one edge, a second longitudinal line of perforations adjacent the other edge and a plurality of transverse lines of perforations extending across the EKG data strip between the first and second longitudinal lines of perforations. The transverse lines of perforations are located at spaced intervals along the length of the EKG strip to thereby divide the central part of the strip into a plurality of longitudinally aligned segments, each of which has a predetermined width between the longitudinal perforations and a predetermined length between two adjacent transverse perforations.

Abstract: An apparatus for recording pneumatic pressures such as those encountered when measuring blood pressure with a sphygmomanometer. A sheet material which is to have information recorded thereon is carried by a suitable support. A frame carries a marking instrument for marking the information on the sheet material, and in addition this frame carries a pressure-responsive device capable of responding to a change in pneumatic pressure and connected with the marking instrument for moving the latter in accordance with the degree of pneumatic pressure.

Abstract: A method and system for recording EEG waveforms whereby the amplitude of the waveform signal in both positive and negative direction is compared with variable levels and a trigger signal produced when the amplitude exceeds a level to cause the strip of recording paper to speed up for at least a predetermined time and to continue for the length of the seizure so that little paper is accumulated during periods of uninteresting activity while a complete readable record is produced of any notable EEG activity, such as an epileptic seizure.

Abstract: In a device for measuring blood sedimentation rate automatically, a light-sensitive paper sheet is disposed so as to be movable relative to a blood sedimentation measuring tube, such as Westergren tube; a slit is provided between the light-sensitive paper and the measuring tube; and lamp means are provided on one side of the measuring tube opposite to the slit. Thus, the shade of the sedimented red blood corpuscles in the measuring tube formed as the light pulses from the lamp means passes through the measuring tube is projected on the light-sensitive paper through the slit with the feed of the paper and light pulses occurring in exact synchronism, and the rate of the blood sedimentation can be automatically recorded on the paper.

Abstract: A compressed data display system. There is disclosed a system for recording over extended periods of time EKG and other vital signs of a patient and for automatically displaying the waveforms in a compressed and readily interpretable manner. The EKG waveform is recorded on looped paper supported by and/or wrapped around rotatable drum or drums which may have cylindrical shape. The EKG is recorded in helical or spiral fashion by simultaneously rotating the drum and transversely moving a galvanometer pen in the direction of the axis of rotation of the drum or cylinder. After the paper is removed, if it is a continuous or closed loop, it can be slit and opened into a single sheet. The recorded EKG waveforms are thus displayed compressed in a line-over-line manner and provide the physician with a clear picture of the patient's heart activity for extended periods of time.

Abstract: A switching adapter that provides a rapid and convenient apparatus for selective recording of vertical eye movements with a single channel recorder in electronystagmograph apparatus. A number of single channel recorders are used in the field to observe the horizontal eye movements elicited by thermally induced vestibular unbalance. In certain types of pathological unbalances, vertical eye movement is also present, therefore, it is highly desirable to be able to also record the vertical eye movement. The switching adapter conveniently converts single channel recorders that are normally used for recording horizontal eye movement for recording vertical nystagmus.