Ob Scientific, Inc.

Bpsure, L.l.c.

Helionx LLC

Bahr Technologies, Inc.

Cas Medical Systems, Inc.

Flextech Systems, Inc.

Meadox Instruments, Inc.

Dennis E Bahr

Alan R Kahn

James L Reuss

Kendall E Post

Kurt W Allen

Michael T Larsen

Kenneth R Clark

Gerhard Von Der Ruhr

Thomas P Blandino

Stephen W Flax

Mark Brian Monson

Erich T Ziemann

Neil K Fortney

Michael Skroch

In a helical resonator ion accelerator ions are injected into a hollow dielectric pipe forming a vacuum chamber along which the ions are accelerated. The dielectric pipe is wrapped with a coil and positioned inside a metal pipe. The dielectric pipe, the coil and the metal pipe are arranged coaxially on an axis along which ions are accelerated. A static or magnetic beam optic is used to radially focus the deuterium ions as they transit the accelerator. A pulse generator coupled to the coil is used to generate a voltage wave pulse. The pulse travels down the axis of the accelerator on the helix formed by the coil. An ion source injects deuterium ions along the dielectric pipe axis. A traveling voltage wave is accelerated by tapering the impedance of the accelerator along the accelerator to reduce the impedance per unit length of the accelerator.

Helical resonator ion accelerator and neutron beam device

A Helical Resonator Ion Accelerator in which ions are injected into a hollow dielectric pipe forming a vacuum chamber along which the ions are accelerated. The pipe is wrapped with a coil and positioned inside a metal pipe. The dielectric pipe, the coil and the metal pipe are arranged coaxially on an axis along which ions are accelerated. The metal pipe is positioned within a high intensity 0.5-3.0 Tesla solenoid. A pulse generator is coupled to the coil to generate a voltage wave pulse. The pulse travels down the axis of the accelerator on the helix formed by the coil. An ion source injects deuteron ions along the axis of the vacuum chamber. A traveling voltage wave is accelerated by tapering the characteristic velocity of the accelerator in the direction of wave propagation by tapering the coil and the outer metal pipe together in a constant ratio.

A limited use medical probe is disclosed, including a memory for maintaining a use value. The medical probe is coupled to a medical device that inhibits its function when the use value reaches a predetermined threshold value, preventing improper use of the probe. The probe memory may also store identification, usage, and clinical data. A probe auto-identification function, a probe re-identification function and a probe functional test sequence are disclosed for the medical probe. After use, a reprocessing step may reset the probe memory, permitting further probe use.

Limited use medical probe

A signal processing method, preferably for extracting a fundamental period from a noisy, low-frequency signal, is disclosed. The signal processing method generally comprises calculating a numerical transform for a number of selected periods by multiplying signal data by discrete points of a sine and a cosine wave of varying period and summing the results. The period of the sine and cosine waves are preferably selected to have a period substantially equivalent to the period of interest when performing the transform.

Method and apparatus for processing a physiological signal

A limited use medical probe is disclosed. The medical probe includes a memory storage component for maintaining a use value, representing either the number of uses and/or the duration of use of the medical probe. The medical probe is coupled to a medical monitoring device which prevents the performance of monitoring functions when the number of uses or the total duration of use reaches a predetermined threshold value, thereby preventing overuse of the probe.

A method and apparatus is provided for distinguishing blood pressure sounds from noise in an automatic blood pressure monitoring system using the information contained in two microphone signals. Two microphones are placed on a patient along an axis of an artery to pick up blood pressure sounds. Pressure is applied to the artery such that the artery opens and closes during each heart cycle, the opening snap of the artery producing a blood pressure sound. The two microphone signals are sampled, filtered, and multiplied together to produce a microphone signal product. The microphone signal product is wave width filtered to remove therefrom portions of the signal having a wave width which is less than a selected minimum wave width value. A blood pressure sound is indicated as being detected when an amplitude of this wave width filtered microphone signal product exceeds a noise signal threshold level. The microphone signal product is also wave width filtered to remove therefrom portions of the signal having a wave width which is greater than a selected maximum wave width value. The amplitude of the resulting noise amplitude signal is used to adjust dynamically the noise signal threshold level in response to changing noise conditions. The detection of blood pressure sounds at a range of applied pressure levels is used to determine the systolic and diastolic blood pressure levels of the patient.

Blood pressure monitoring with improved noise rejection

A method and apparatus for automatically recognizing meaningful patterns in non-stationary periodic data is provided. The invention may be used in making measurements of physiological phenomena, such as arterial blood pressure, wherein data of interest is undergoing small changes in timing and magnitude in succeeding cycles, and wherein noise artifacts are detected along with the data of interest. Data points of interest are identified by grouping all received data points into family groups of multi-dimensional data points wherein each data point in the family group has dimensional values similar to at least one other data point in the family. The present invention may preferably be employed for the determination of a patient's systolic and diastolic blood pressure levels. For this application, the data points include a time dimension value corresponding to the delay time between an ECG signal and the detection of a potential blood pressure sound by a microphone placed in an inflatable cuff on the arm of a patient, and a magnitude dimension value corresponding to the cuff pressure at the time of the potential blood pressure sound detection. Data points are collected for a series of cuff pressures ranging from above the systolic blood pressure level of the patient to below the diastolic blood pressure level of the patient. The highest and lowest pressures of data points in the family containing the largest number of data points are used to derive the systolic and diastolic blood pressure levels of the patient, respectively.

Coherent pattern identification in non-stationary periodic data and

A method and apparatus is provided for detecting blood pressure sounds produced by the opening snap of an artery in a patient in the presence of significant noise using the phase information contained in two microphone signals. The two microphones are placed on a patient along the axis of an artery with their centers separated by a distance such that blood pressure sounds picked up by the microphones will be out of phase. Pressure is applied to the artery such that the artery opens and closes during each heart cycle, the opening snap of the artery producing blood pressure sounds. The two microphone signals are filtered, preferably using band pass filters having pass bands corresponding to the frequency of the blood pressure sounds. The filtered microphone signals are sampled and multiplied together or convolved in the frequency domain to generate a microphone signal product. If the microphone signal product is negative, the detection of a valid blood pressure signal for that sampling time is indicated. In an alternative embodiment, the slope of the two microphone signals at the sample time is also determined. A valid blood pressure signal is indicated when the microphone signal product is negative and either the two microphone signal slopes have inverse signs or are both less than a selected slope threshold. A selected number of consecutive valid blood pressure signal detections indicates the detection of a blood pressure sound. The detection of blood pressure sounds at a range of cuff pressures is used to determine the systolic and diastolic blood pressure levels of the patient.

Method and apparatus for detecting blood pressure by blood pressure

The present invention is a method of processing and writing data to a database wherein the method comprises four broad steps: 1) manipulating data files into a more compact and efficient bit-encoded form and preparing the files to receive additional data to link the files; 2) linking the files with pointers to form an overall data structure; 3) determining the potential physical memory address for the files' data by optimizing available memory space for a given memory media wherein the files are partitioned into blocks of data which are sufficiently inclusive to permit retrieval of all required data with a single memory media read, yet small enough to allow all of the physical memory space to be fully utilized; and 4) generating reference tables to be interspersed with the data blocks wherein the reference tables track the physical location of related data, obviating the need for additional disk reads. The invention further comprises a system wherein said method is performed on a database contained on a first computer system so that the database can be written to a memory media of fixed size which can be used with a second computer system, such that memory access speed is enhanced, the density of information stored on the memory media is increased, yet the computational power needed to retrieve such information is reduced.

System for the compacting and logical linking of data blocks in files to

A preamplifier system adapted for a Loran receiver includes a buffer amplifier receiving the signal from the antenna at its input and a tuned circuit connected between the input of the buffer amplifier and ground. The tuned circuit includes a parallel combination of a resistance, capacitance and inductance with values selected such that a resonant frequency is provided substantially at or near the carrier frequency of the Loran signal to pass it while higher and lower frequencies, constituting extraneous noise signals, are substantially attenuated. In particular, low frequency, e.g. 60 Hz signals and DC from sources such as precipitation static, are shunted to ground through the parallel inductor in the tuned circuit so that these low frequency components do not affect the performance of the receiver. A secondary filter section is connected to the output of the buffer amplifier and has components that may be selected in value such that the overall transfer function of the preamplifier, including the tuned input circuit, has a desired bandpass characteristic. Thermal noise contributed by the parallel resistor in the tuned circuit may be reduced by feeding back the output of the buffer amplifier through the resistor to effectively reduce its noise contribution while leaving the effective input resistance the same. Notch filters may be incorporated with the input tuned circuit to reject strong extraneous signals within the passband.

Receiver preamplifier with tuned circuit adapted for Loran reception

A radio signal containing Loran C pulses from stations of interest is received and periodically sampled to convert the input signal to sample data. The data is assigned to memory locations within an acquisition memory at positions in the memory which correspond to specific times within the group repetition interval (GRI) of the Loran chain of interest. A GRI counter assigns the locations in the memory to which the data are written and cycles the memory after the completion of each GRI so that new data corresponding to a new set of pulses from the master and secondary stations of the Loran C chain will be assigned to essentially the same memory locations as data acquired during a previous GRI. The new data is ensemble averaged with the old data contained in the memory locations and the averaged data stored back in the memory. As data is collected and averaged over a sufficient number of GRI's, any signals present in the received radio signal which are not synchronous with the GRI will tend to be averaged out, improving the signal to noise ratio of the Loran C pulses in the memory. Averaging of the sampled input signal over several GRI's in this manner minimizes the effect of sporadic noise, continuous wave interference and cross rate interference. After completion of the averaging process, the data in the acquisition memory may be searched to determine the time differences between the master and secondary pulses in a manner normally carried out in Loran C receivers.

Apparatus and method for receiving and proessing Loran signals

The device measures blood pressure automatically using the oscillometric technique. The device includes a pressure cuff which is automatically inflated to an initial pressure which is calculated to be above the subject's systolic pressure. The cuff is then deflated stepwise in preset pressure increments while cuff pressure oscillations are sensed at each cuff pressure level and stored in a computer incorporated into the device. Cuff deflation is continued until the cuff pressure is below the subject's diastolic pressure whereupon the cuff is automatically deflated. The computer then fits a calculated parabolic curve onto the greatest cuff pressure oscillation and onto a lesser oscillation on each side of the greatest oscillation. From the thusly derived curve, the computer determines the mean blood pressure, and the systolic and diastolic blood pressures.

Automatic blood pressure measuring device and method

A closed pressure monitoring system (20) is disclosed in which a pump (27) delivers gas on a supply line (22, 29) through a first accumulator chamber (30) to a load device (21) and returns the gas on a return line (23, 28) through a second accumulator chamber (34) to the pump (27). After pressures in the first and second chambers stabilize, the pressures are compared, and a leak warning signal is given if the compared pressures changed with respect to one another over time. The system is particularly adapted to use a pressure sensor as the load (21) which is implanted within a human patient. The pressure sensor receives air from a restrictor (32) in the supply line (22, 29) and is operative to maintain the pressure in the supply line substantially equal to the pressure surrounding the sensor.

Growing community of inventors

Middleton, WI, United States of America

Dennis E Bahr