Abstract:
A method is provided for calibrating sensors (14) used to analyze characteristics of physiologic fluids such as blood. The method involves the use of a sensor assembly (12) having an analyte responsive sensor (14) in communication with a physiologic line (28) and a conduit passageway (16). The method involves exposing the sensor (14) to a reference sample, thereby producing a sensor response. The method also allows performing quality control on sensors (14). Also provided is an apparatus (10) with which the claimed method may be practiced.
Abstract:
A method and apparatus allows for simple correction of resctricted spinal motion. The clinician applies a uniform low energy diagnostic impulse to each vertebral segment of interest (640) and the resulting force waveform is recorded. The force wavefroms of each diagnostic impulse are compared to determine the relative compliance of each vertebral segment. The clinician then selects the vertebral segment to be adjusted (655) on the basis of identification of fixated or hypo-mobile segments and high compliance or hyper-mobile segments. The last step may or may not include comparison of the post adjustment compliance of the spinal system under analysis (515) with the compliance before adjustments were performed on the spine.
Abstract:
The present invention is a method and apparatus (10) for disease, injury or condition screening or sensing wherein bio-potentials are received from a plurality of measuring sensors (26a-d) located in the area of a suspected disease, injury or condition change site. These potentials are then processed by a processor (42), and the processed values are provided to a particular type of neural network (44) or a combination of neural networks uniquely adapted to receive and analyze data of an identifiable type to provide an indication (50) of specific conditions.
Abstract:
An impedance cardiograph (10) which determines cardiac output from a measurement of variations of chest impedance (2), provides method of calculating the effect of patient volume on the measurement from measurable patient height (H) and chest circumference (C), and provides a correction process that identifies as a source of error variations in the first derivative of impedance. This latter source of error is minimized by preprocessing the impedance derivative value with a compression function which reduces the range of values of the impedance derivative when that value differs significantly from a norm of the population.
Abstract:
An impedance monitor (100) is adapted for use in long-term monitoring of intracellular (neuronal) swelling in the brains (102) of mammals over periods of hours or days. The monitor has an electrically isolated current source (103), supplying a one microampere AC square waveform at 200 Hz. This current is passed through an outer pair of electrodes (104, 105) of a four-electrode arrangement having skin electrodes, extradural electrodes, or in some cases surface electrodes embedded in surgical retractors. Sensing electrode pairs (107, 108) may also detect EEG activity. Impedance changes are displayed graphically (109). Multiple electrode arrays may be used for localisation of affected portions of the brain. Even trans-cranially measured impedances reflect intracellular oedema and are clinically useful indicators of treatment efficacy and outcome in cases of ischaemia, asphyxia, trauma, and the like.
Abstract:
A magnetic position and orientation determining system uses magnetic fields, desirably comprising uniform fields from Helmholtz coils (34, 36, 38) positioned on opposite sides of a sensing volume and gradient fields generated by the same coils. By monitoring field components detected at the probes (50) during application of these fields, the position and orientation of the probe (50) in the field can be deduced. A representation (108) of the probe (50) can be superposed on a separately acquired image of the subject to show the position and orientation of the probe (50) with respect to the subject.
Abstract:
Method of operating, catheter and catherization system for measuring electrical impedances in blood vessels within an annular area around the catheter. The catheter contains excitation electrodes (T1, T2 & S1, S2) between which the impedance is measured, the measurement being a potential difference between measuring electrodes (Me1, Me2, Me3) present between those excitation electrodes. The two pairs of excitation electrodes are electrically driven in opposition to set up a controllable pattern of electric field lines (a so-called "counter current field"). By varying the amplitudes of the two excitaton currents, the electric field can be adjusted such that: a) no (or hardly any) current flows between the measuring electrodes (the "quenching relation"), and b) at a distance away from the measuring electrodes the electric field lines are substantially perpendicular to the longitudinal axis of the catheter. The average impedance of the area-to-be-measured and that of the area outside of this given area can then be measured separately.
Abstract:
A system for externally locating the depth and orientation of a catheter (9) in tissue with an external probe (12) which generates a virtual rotating magnetic field. The catheter (9) includes an inductive coil (30) for developing an induced signal in response to the virtual rotating magnetic field. An indicating device (6) such as a light bar display or digital readout indicates the strength of the induced signal for locating, independently of the relative angular orientation of the probe and the catheter, the depth in the tissue of the catheter.
Abstract:
The invention relates to medical technique and in particular to a device for galvanopuncture diagnostics. The aim of the invention is to increase the reliability and to shorten the duration of the testing procedure. The aim is achieved due to the fact that a unit (12) of microresonance circuits consists of commutation cells connected to a control bus (14) intended for sending commands for grouped connection of these cells, whereas the output of the unit of microresonance circuits is connected to a unit (11) for cancelling the bioenergetic burdening of the patient, connected to an electric conductivity measuring unit (1).
Abstract:
The invention provides a method and an instrument for measuring sensory functions (hearing vision, smell, tactile sense and pain sensitivity) of a human or an animal, whereby the sense under investigation is stimulated and the resulting change of a skin potential is recorded. Preferably, another stimulus such as an electric potential is applied, optionally several times with varying intervals and varying intensity, prior to the stimulation of the sense under investigation.