Apparatus and method for data processing of physiological signals

• US 9,585,622 B2
• Filed: 04/05/2012
• Issued: 03/07/2017
• Est. Priority Date: 04/12/2011
• Status: Active Grant

• Current Assignee: Dragerwerk AG & Company KGaA (FPS Vermögensverwaltung GmbH)
• Original Assignee: Dragerwerk AG & Company KGaA (FPS Vermögensverwaltung GmbH)
• Inventors: Sattler, Frank, Eger, Marcus
• Primary Examiner(s): Layno, Carl H
• Assistant Examiner(s): Morales, Jon Eric C
• Application Number:
  US14/111,222
• Publication Number:
  US 20140142395A1
• Time in Patent Office: 1,797 Days
• Field of Search: 600/546, 128/204.23
• US Class Current: 1/1
• CPC Class Codes: A61B 5/0205 Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition
• CPC Class Codes: A61B 5/021 Measuring pressure in heart or blood vessels A61B5/0205 takes precedence
• CPC Class Codes: A61B 5/14542 for measuring blood gases A61B5/14551 takes precedence
• CPC Class Codes: A61B 5/316 Modalities, i.e. specific diagnostic methods
• CPC Class Codes: A61B 5/318 Heart-related electrical modalities, e.g. electrocardiography [ECG]
• CPC Class Codes: A61B 5/389 Electromyography [EMG]
• CPC Class Codes: A61B 5/4836 Diagnosis combined with treatment in closed-loop systems or methods A61B5/0036 takes precedence
• CPC Class Codes: A61B 5/7203 for noise prevention, reduction or removal
• CPC Class Codes: A61B 5/725 using specific filters therefor, e.g. Kalman or adaptive filters A61B5/316 take precedence
• CPC Class Codes: A61M 16/00 Devices for influencing the respiratory system of patients by gas treatment, e.g. mouth-to-mouth respiration; Tracheal tubes stimulating the respiratory movement by mechanical, pneumatic or electrical means, iron lungs combined with gas breathing means A61H31/00
• CPC Class Codes: A61M 16/0051 with alarm devices
• CPC Class Codes: A61M 16/0057 Pumps therefor
• CPC Class Codes: A61M 16/024 including calculation means, e.g. using a processor
• CPC Class Codes: A61M 2230/00 Measuring parameters of the user
• CPC Class Codes: A61M 2230/005 Parameter used as control input for the apparatus
• CPC Class Codes: A61M 2230/04 Heartbeat characteristics, e.g. ECG, blood pressure modulation
• CPC Class Codes: A61M 2230/42 Rate
• CPC Class Codes: A61M 2230/60 Muscle strain, i.e. measured on the user
• CPC Class Codes: H03H 17/0261 Non linear filters
• CPC Class Codes: H03H 17/0294 Variable filters; Programmable filters
• CPC Class Codes: H03H 2021/0083 : Shadow filter, i.e. one of two filters which are simultaneously adapted, wherein the results of adapting the shadow filter are used for adapting the other filter

Abstract

A filter apparatus (100) having a signal input (101) to which an input signal is applied which contains a useful component and a noise component, a fast signal path (102) and a slow signal path (103) arranged in parallel therewith. The fast signal path and the slow signal path are coupled to the signal input. The fast signal path contains a filter in order to prompt fast filtering of the input signal. The slow signal path contains a filter in order to prompt slow filtering of the input signal. An output of the slow signal path is coupled to the fast signal path by means of a signal line (106). A signal output (104) which is coupled to the fast signal path has an output signal applied to it which essentially contains useful components of the input signal.

Claims

1. A filter apparatus comprising:

a signal input, at which an input signal is present, which input signal contains a useful component and a noise component;

a fast signal path, the fast signal path having a fast signal path input and a fast signal path output;

a slow signal path arranged in parallel to the fast signal path, the slow signal path having a slow signal path input and a slow signal path output;

a signal line coupling the slow signal path output with the fast signal path to change a characteristic of said fast signal path, wherein the signal input is coupled with the fast signal path input and of the slow signal path input, wherein the fast signal path contains a filter to bring about fast filtering of the input signal and wherein the slow signal path contains a filter to bring about slow filtering of the input signal;

a signal output coupled with the fast signal path output and at which an output signal, which contains essentially useful components of the input signal, is present; and

another signal line via which a signal is returned from the fast signal path to the slow signal path to affect the functional characteristic of the slow filter path, wherein an output of the fast signal path is coupled via the another signal line with an input of the slow signal path and wherein physiological signals from a patient, which are used after their filtering to drive a respirator, are present at the signal input, wherein said input signal is a physiological signal from a patient, said physiological signal passing through said fast signal path and through said slow signal path, wherein a signal travel time in said fast signal path is shorter by a factor of at least two than a signal travel time in said slow signal path, said another signal line connecting said fast signal path output of said fast signal path with said slow signal path input of said slow signal path to change said functional characteristic of said slow filter path, wherein said filter of said fast signal path comprises nonlinear properties, said filter of said slow signal path comprising linear properties or an adaptive filter.

2. A filter apparatus in accordance with claim 1, wherein the slow signal path is provided with an artifact analysis block, which has inputs for additional signals.

3. A filter apparatus comprising:

a plurality of signal inputs, each having an input signal, which contains a useful component and a noise component;

a plurality of fast signal paths arranged in parallel;

a plurality of slow signal paths arranged in parallel;

wherein each of the plurality of signal inputs is coupled with an input of the plurality of fast signal paths arranged in parallel and of the plurality of slow signal paths arranged in parallel, wherein each fast signal path contains a filter to bring about fast filtering of the input signal, wherein each slow signal path contains a filter to bring about slow filtering of the input signal;

an accounting/decision unit;

signal lines, wherein each slow signal path is coupled with corresponding inputs of the accounting/decision unit via the respective signal lines, wherein each fast signal path is coupled with corresponding outputs of the accounting/decision unit via the respective signal lines; and

a plurality of signal outputs, which are coupled each with outputs of the fast signal paths and at which respective output signals, which contain essentially useful components of the input signals, are present, wherein a signal travel time in each of said fast signal paths is shorter by a factor of at least two than a signal travel time in each of said slow signal paths, wherein physiological signals, which are present at said signal inputs and which are present at said signal outputs after their filtering by the filter apparatus, are used to drive a respirator, said filter of each of said plurality of fast signal paths comprising nonlinear properties and said filter of each of said plurality of slow signal paths comprising linear properties or an adaptive filter, said outputs of said fast signal paths being coupled with corresponding inputs of said accounting/decision unit via respective signal lines.

4. A filter apparatus in accordance with claim 3, wherein the outputs of the fast signal paths are coupled with corresponding inputs of the accounting/decision unit via the respective signal lines.

5. A filter apparatus in accordance with claim 3 for the real-time filtering of physiological signals from a patient, which are used after their filtering to drive a respirator.

6. A filter apparatus in accordance with claim 3, wherein the slow signal path is provided with an artifact analysis block, which has inputs for additional signals.

7. A method for the real-time filtering of physiological signals with a useful component and with a noise component, the method comprising the steps of:

providing a fast signal path, through which the physiological signal is to pass, with a signal input and with a signal output;

providing a slow signal path through which the physiological signal is to pass in parallel thereto with a signal input and with a signal output;

providing a connection and connecting the signal output of the fast signal path with the signal output of the slow signal path as a signal output;

providing another connection and connecting the signal output of the fast signal path with the signal input of the slow signal path;

coupling the physiological signal in parallel into the input of the fast signal path and into the input of the slow signal path;

passing the physiological signal through the fast signal path fast, providing a filtered output signal, which contains essentially the useful component of the physiological signal and in which the noise component of the physiological signal is not suppressed completely by the fast filtering at the signal output of the fast signal path, wherein the characteristic of the fast signal path is affected via the connection; and

passing the physiological signal through the slow signal path slowly, wherein the characteristic of the slow signal path is affected via the further connection, and providing a filtered output signal, which contains essentially the useful component of the physiological signal and in which the noise component of the physiological signal is essentially suppressed by the slow filtering at the signal output of the slow signal path, wherein a filtered output signal, which contains essentially the useful component of the physiological signal and in which the noise component of the physiological signal is essentially suppressed, is present at the signal output without time delay relative to the signal output of the fast signal path, wherein a signal travel time in said fast signal path is shorter by a factor of at least two than a signal travel time in said slow signal path, wherein a parameter of the slow signal path is provided into the fast signal path via a signal line, wherein a feedback signal is provided from said fast signal path to said slow signal path via another signal line to affect a functional characteristic of said slow filter path.

9. A method in accordance with claim 7, wherein the noise component of the physiological signal is not suppressed completely in the fast signal path.

10. A method in accordance with claim 7, wherein the noise component of the physiological signal is suppressed essentially completely in the slow signal path.

8. A method for the real-time filtering of physiological signals with a useful component and with a noise component, the method comprising the steps of:

feeding a noise-affected physiological signal as an input signal at a signal input of a fast signal path and, in parallel and simultaneously in time therewith, into a signal input of a slow signal path;

slow filtering the noise-affected physiological signal in the slow signal path;

feeding a parameter of the slow signal path into the fast signal path;

fast filtering said noise-affected physiological signal via said fast filter path based on said parameter to provide a noise-suppressed physiological signal, which is not delayed relative to the pass through the slow signal path of the physiological signal, as a filtered output signal; and

returning a feedback signal of the fast signal path into the slow signal path, wherein a threshold is determined based on said parameter, said noise-affected physiological signal being filtered via said fast filter path based on said threshold, wherein a signal travel time in said fast signal path is shorter by a factor of at least two than a signal travel time in said slow signal path, wherein said fast signal path has a filter with nonlinear properties and said slow signal path has a filter with linear properties or an adaptive filter.