General Electric Company

Ge Medical Systems Information Technologies Gmbh

Johnson & Johnson Medical Gmbh

Critikon Company, L.l.c.

Critikon, Inc

Lawrence T Hersh

Sai Kolluri

Richard Medero

Bruce Arnold Friedman

John W Booth

Robert F Donehoo

Ralph Thomas Hoctor

Rush W Hood, Jr

Rush Winslow Hood, Jr

Christopher J Dedyo

William Roberts

Heather Menshouse

A system and method for processing oscillometric data from a plurality of pressure steps to determine the blood pressure of a patient. A heart rate monitor connected to the patient acquires the patient's heart rate. A time-to-frequency domain converter receives oscillometric data and converts the oscillometric data into the frequency domain. Based upon the calculated heart rate, the system and method filters the frequency domain oscillometric signal with pass bands centered at the fundamental frequency and at least one fundamental frequency. The energy of the frequency domain signal within the pass bands is compared to at least a portion of the energy of the frequency domain oscillometric signal outside of the pass bands. Based upon the comparison, the signal determines whether the signal at the current pressure step should be utilized in calculating the blood pressure of the patient.

Use of the frequency spectrum of artifact in oscillometry

A non-invasive blood pressure system is disclosed herein. The non-invasive blood pressure system includes a pressure transducer configured to obtain pressure data comprising a transient baseline effects component. The non-invasive blood pressure system also includes a processor adapted to receive the pressure data from the pressure transducer. The processor is configured to generate a transient baseline effects model, and to implement the transient baseline effects model to at least partially remove the transient baseline effects component of the pressure data. The removal of the transient baseline effects component from the pressure data eliminates a potential source of error and thereby enables a more accurate blood pressure estimate.

System and method for a non-invasive blood pressure monitor

A system for processing oscillometric data from a plurality of pressure steps to determine the blood pressure of a patient as disclosed herein. A heart rate monitor connected to the patient acquires the patient's heart rate. A time to frequency domain converter receives oscillometric data and converts the oscillometric data into the frequency domain. A harmonic frequency calculator is connected to the heart rate monitor and derives at least the heart rate fundamental frequency. A filter connected to the time to frequency domain converter and the harmonic frequency calculator that produces a filter frequency domain oscillometric signal. A reconstruction calculator receives the filtered frequency domain oscillometric signal and reconstructs a time domain oscillometric signal. A method of computing an oscillometric envelope for use in determining the blood pressure of a patient is also disclosed herein.

Adaptive frequency domain filtering for improved non-invasive blood pressure estimation

A method of measuring blood pressure of a patient is provided. The method comprises inflating a blood pressure cuff to a user selectable target pressure and subsequently further inflating or deflating the blood pressure cuff in a stepwise manner by a predetermined pressure amount. At each pressure step in a first sequence of alternate steps of cuff pressure variation, the occurrence of at least two successive oscillometric pulses with matching pulse amplitude and other possible matching criteria is identified. The blood pressure cuff is inflated following the identification. Further a single oscillometric pulse is obtained at each pressure step in a second sequence of alternate steps of cuff pressure variation. The pattern of inflating, obtaining two matching oscillometric pulses, inflating, and obtaining a single oscillometric pulse is repeated until sufficient oscillometric envelope information is obtained for determining one or more blood pressure parameters of the patient.

System and method for a non-invasive blood pressure measurement

A method and system for determining pulse rate of a patient are disclosed. The method and system include acquiring measured information for at least one pulse at a pressure step, determining and storing quality values for the at least one pulse at the pressure step, analyzing pulse matching criteria for the pressure step, and determining pulse rate based on the measured information, quality values, and pulse matching criteria.

Method and system for determination of pulse rate

A method and system for operating a non-invasive blood pressure monitor that utilizes an SpOplethysmograph waveform to determine the initial inflation pressure for the NIBP monitor. A pulse sensor is placed on the patient's limb distal to the blood pressure cuff and provides a pulse waveform to the NIBP monitor. The NIBP monitor calculates a second derivative of the pulse waveform, which includes a series of acceleration peaks corresponding to pulse signals within the pulse waveform. When the blood pressure cuff reaches systolic pressure, the acceleration peaks contained within the acceleration waveform are eliminated, thus providing an indication that the cuff pressure has reached systolic pressure for the patient. Use of the SPOplethysmograph signal to determine the initial inflation pressure reduces both the over-inflation of the blood pressure cuff and the under-inflation of the blood pressure cuff, which increases the rate at which the blood pressure measurement can be made while increasing patient comfort.

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A method of utilizing maternal-fetal monitoring system to monitor the physiological properties of both a maternal patient and a fetus. The method places a series of ECG electrodes across the maternal patient's abdomen and receives ECG input waveforms across a plurality of separate channels. The method processes the channels using an ICA algorithm to generate a series of ICA output waveforms. The ICA output waveforms are analyzed for each individual epoch to determine which of the channels include a maternal signal or a fetal signal source. Based upon the determination of which channel includes the fetal and maternal signals, further processing is carried out on the ICA output waveform on the identified channel to obtain physiological properties for the patient and the fetus. During the next epoch, the same signal processing occurs, such that the system can identify the fetal and maternal signals even as the fetal and maternal jump channels from one epoch to another.

Method of fetal and maternal ECG identification across multiple EPOCHS

A method for estimating systolic and diastolic pressure is disclosed herein. The method includes obtaining a predetermined type of blood pressure data from a patient, and providing previously acquired blood pressure data obtained from a plurality of different subjects. The method also includes implementing the previously acquired blood pressure data to select systolic and diastolic amplitude ratios that most closely correlate with the predetermined type of blood pressure data obtained from the patient. The selected systolic and diastolic amplitude ratios are adapted to compensate for the effects of arterial compliance. The method also includes implementing the selected systolic and diastolic amplitude ratios to generate a systolic and diastolic blood pressure estimates.

Non-invasive blood pressure determination method

A method of utilizing a maternal-fetal monitoring system to monitor the physiological properties of both a maternal patient and a fetus. A series of ECG electrodes are placed across the maternal patient's abdomen and receives ECG input waveforms across sixteen separate channels. The sixteen channels of information are processed using an ICA algorithm to generate a series of ICA output waveforms and a transfer matrix. Following the current epoch, the transfer matrix is applied to the input waveforms on a continuous basis. The conditioned input waveforms are displayed immediately following the first epoch and prior to the expiration of a subsequent epoch. The transfer matrix for the second epoch is combined with the transfer matrix for the first epoch to generate an updated transfer matrix. Various filtering operations on the transfer matrix coefficients may be used to find the updated transfer matrix before the end of the current epoch.

Extrapolating ICA knowledge from one epoch to another for improved fetal ECG separation

A blood pressure measurement system that utilizes a non-invasive blood pressure (NIBP) monitor having a blood pressure cuff and pressure transducer. The measurement system provides a plurality of separate processing techniques that each receive a plurality of oscillometric data values from the pressure transducer. Each of the processing techniques separately constructs an oscillometric envelope based upon the oscillometric data values. Based upon the plurality of separate oscillometric envelopes, the system compares the envelopes and develops a calculated blood pressure from the plurality of envelopes. The calculated blood pressure is then displayed by the NIBP system. The plurality of oscillometric envelopes can be compared and combined in different manners to calculate the patient's blood pressure from the plurality of different processing techniques.

Computation of blood pressure using different signal processing channels

A blood pressure measurement system that utilizes both a non-invasive blood pressure (NIBP) monitor having a blood pressure cuff and a continuous non-invasive blood pressure (CNIBP) monitor. During operation of the NIBP monitor, the blood pressure cuff is inflated to an initial inflation pressure greater than the systolic blood pressure for the patient being monitored. The CNIBP monitor calculates an estimated blood pressure that is supplied to the NIBP monitor. The NIBP monitor utilizes the continuous, estimated blood pressure to select a target inflation pressure for the blood pressure cuff. During operation of the NIBP monitor, the size of the pressure steps from the initial inflation pressure to a final pressure can be varied based upon the continuous blood pressure estimate from the NIBP monitor.

Non-invasive blood pressure monitor with improved performance

A method and technique for the continuous, non-invasive measurement of blood pressure. The blood pressure measurement technique of the present invention utilizes ultrasound measurements to determine the diameter of the blood vessel in which the blood pressure is being measured as well as the flow rate of blood at both an input point and an output point along the blood vessel. The system utilizes a transmission line model to relate various blood vessel measurements with electrical components. The transmission line model, in combination with data management techniques including state variable representations and Kalman filtering, is used to develop a blood pressure measurement in real time.

Continuous, non-invasive technique for determining blood pressure using a transmission line model and transcutaneous ultrasound measurements

A method and system for determining when to make a reversion to smaller cuff pressure steps during an oscillometric blood pressure measurement is disclosed. The method and system comprise comparing conformance of oscillometric envelope blood pressure data with previous blood pressure data, including measuring a shift between the oscillometric envelope blood pressure data and an oscillometric envelope derived from the previous blood pressure data. In addition, the method and system include making a reversion decision based on whether the shift exceeds an allowable threshold. Once a reversion decision is made a subsequent decision may be made as to the need for increasing the cuff pressure level.

Method and system for cuff pressure reversions

A method and system for operating a non-invasive blood pressure monitor that utilizes an SpOplethysmographic signal to reduce the time required to obtain an estimation of a patient's blood pressure. During operation of the NIBP monitor, the NIBP monitor utilizes the SpOplethysmographic signal to determine a timing period and a deflation period for each pulse associated with the patient's heartbeat. Upon receiving an oscillation pulse, the NIBP monitor determines the oscillation amplitude during the timing period and deflates the blood pressure cuff during the deflation period immediately following the timing period. Preferably, the deflation period occurs during the same oscillation pulse used to calculate the oscillation pulse amplitude to decrease the amount of time required to obtain a blood pressure estimate from the patient.

A method and system for operating a non-invasive blood pressure monitor that utilizes an SpOplethysmograph signal to determine the initial inflation pressure for the blood pressure cuff of the NIBP monitor. A pulse sensor is placed on the patient's limb distal to the blood pressure cuff such that as the blood pressure cuff is inflated, the pulse signals from the pulse sensor will be reduced. When the blood pressure cuff reaches systolic pressure, the pulse signals from the pulse sensor will be initially attenuated and eventually eliminated, thus providing an indication that the cuff pressure has reached systolic pressure for the patient. The central processor of the NIBP monitor compares the pulse signals during cuff inflation to an average pulse signal and terminates the inflation of the blood pressure cuff upon sufficient attenuation. The use of the SpOplethysmograph signal to determine the initial inflation pressure reduces both the over-inflation of the blood pressure cuff and the under-inflation of the blood pressure cuff which increases the rate at which the blood pressure measurement can be made while increasing patient comfort.

Growing community of inventors

Milwaukee, WI, United States of America

Lawrence T Hersh