Separation of interference pulses from physiological pulses in a pressure signal
First Claim
1. A device for processing a pressure signal obtained from a pressure sensor in an extracorporeal fluid circuit, said device comprising:
- an input for receiving the pressure signal from the pressure sensor; and
a signal processor connected to the input and being configured to;
extract, from the pressure signal, a signal segment that comprises a sequence of interference pulses originating from an interference generator associated with the extracorporeal fluid circuit, and a sequence of physiological pulses originating from a physiological pulse generator in a subject which is connected to the extracorporeal fluid circuit;
process the signal segment for separation of the interference pulses from the physiological pulses by;
a) subtracting at least one initial template signal from the signal segment to generate a first difference signal that represents the sequence of physiological pulses and residuals of the interference pulses;
b) processing the first difference signal to generate a first template signal in which the residuals of the interference pulses are suppressed in relation to the sequence of physiological pulses;
c) subtracting at least the first template signal from the signal segment to generate a second difference signal that represents the sequence of interference pulses and residuals of the physiological pulses; and
d) processing the second difference signal to generate a second template signal in which the residuals of the physiological pulses are suppressed in relation to the sequence of interference pulses; and
evaluating a property of the extracorporeal fluid circuit using the second template signal.
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Accused Products
Abstract
A filtering device receives a signal from a pressure sensor in an extracorporeal fluid circuit connected to a subject and processes the signal to separate physiological pulses, e.g. from the subject'"'"'s heart, from interference pulses, e.g. from a pump in the fluid circuit. The device repeatedly (iteratively) processes a signal segment by alternately subtracting (S3) a template signal from the signal segment, and applying a refinement processing (S6) to the resulting difference signal to generate a new template signal. By proper selection (S2) of the initial template signal, consecutive difference signals will alternately approximate the sequence of interference pulses in the signal segment and the sequence of physiological pulses in the signal segment. The refinement processing (S6) aims at alternately cleaning up unwanted residuals from interference pulses and physiological pulses, respectively, in the respective difference signal, so as to improve the accuracy of the template signal between the subtractions.
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Citations
32 Claims
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1. A device for processing a pressure signal obtained from a pressure sensor in an extracorporeal fluid circuit, said device comprising:
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an input for receiving the pressure signal from the pressure sensor; and a signal processor connected to the input and being configured to; extract, from the pressure signal, a signal segment that comprises a sequence of interference pulses originating from an interference generator associated with the extracorporeal fluid circuit, and a sequence of physiological pulses originating from a physiological pulse generator in a subject which is connected to the extracorporeal fluid circuit; process the signal segment for separation of the interference pulses from the physiological pulses by; a) subtracting at least one initial template signal from the signal segment to generate a first difference signal that represents the sequence of physiological pulses and residuals of the interference pulses; b) processing the first difference signal to generate a first template signal in which the residuals of the interference pulses are suppressed in relation to the sequence of physiological pulses; c) subtracting at least the first template signal from the signal segment to generate a second difference signal that represents the sequence of interference pulses and residuals of the physiological pulses; and d) processing the second difference signal to generate a second template signal in which the residuals of the physiological pulses are suppressed in relation to the sequence of interference pulses; and evaluating a property of the extracorporeal fluid circuit using the second template signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 27)
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20. A method of processing a pressure signal obtained from a pressure sensor in an extracorporeal fluid circuit, said method comprising:
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extracting, from the pressure signal, a signal segment that comprises a sequence of interference pulses originating from an interference generator associated with the extracorporeal fluid circuit, and a sequence of physiological pulses originating from a physiological pulse generator in a subject which is connected to the extracorporeal fluid circuit; subtracting at least one initial template signal from the signal segment to generate a first difference signal that represents the sequence of physiological pulses and residuals of the interference pulses; processing the first difference signal to generate a first template signal in which the residuals of the interference pulses are suppressed in relation to the sequence of physiological pulses; subtracting at least the first template signal from the signal segment to generate a second difference signal that represents the sequence of interference pulses and residuals of the physiological pulses; processing the second difference signal to generate a second template signal in which the residuals of the physiological pulses are suppressed in relation to the sequence of interference pulses; and evaluating a property of the extracorporeal fluid circuit using the second template signal. - View Dependent Claims (21, 28)
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22. A device for processing a pressure signal obtained from a pressure sensor in an extracorporeal fluid circuit, said device comprising:
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segmentation means configured to receive the pressure signal and extract, from the pressure signal, a signal segment that comprises a sequence of interference pulses originating from an interference generator associated with the extracorporeal fluid circuit, and a sequence of physiological pulses originating from a physiological pulse generator in a subject which is connected to the extracorporeal fluid circuit; first subtraction means configured to subtract at least one initial template signal from the signal segment to generate a first difference signal that represents the sequence of physiological pulses and residuals of the interference pulses; first refinement means configured to process the first difference signal to generate a first template signal in which the residuals of the interference pulses are suppressed in relation to the sequence of physiological pulses; second subtraction means configured to subtract at least the first template signal from the signal segment to generate a second difference signal that represents the sequence of interference pulses and residuals of the physiological pulses; second refinement means configured to process the second difference signal to generate a second template signal in which the residuals of the physiological pulses are suppressed in relation to the sequence of interference pulses; and evaluation means configured to evaluate a property of the extracorporeal fluid circuit using the second template signal. - View Dependent Claims (29)
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23. A device for processing a pressure signal obtained from a pressure sensor in an extracorporeal fluid circuit, said device comprising:
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an input for receiving the pressure signal from the pressure sensor; and a signal processor connected to the input and being configured to; extract, from the pressure signal, a signal segment that comprises a sequence of interference pulses originating from an interference generator associated with the extracorporeal fluid circuit, and a sequence of physiological pulses originating from a physiological pulse generator in a subject which is connected to the extracorporeal fluid circuit; process the signal segment for separation of the interference pulses from the physiological pulses by; a) subtracting at least one initial template signal from the signal segment to generate a first difference signal that represents the sequence of interference pulses and residuals of the physiological pulses, b) processing the first difference signal to generate a first template signal in which the residuals of the physiological pulses are suppressed in relation to the sequence of interference pulses, c) subtracting at least the first template signal from the signal segment to generate a second difference signal that represents the sequence of physiological pulses and residuals of the interference pulses, and d) processing the second difference signal to generate a second template signal in which the residuals of the interference pulses are suppressed in relation to the sequence of physiological pulses; and evaluate a cardiovascular property of the subject using the second template signal. - View Dependent Claims (30)
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24. A method of processing a pressure signal obtained from a pressure sensor in an extracorporeal fluid circuit, said method comprising:
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extracting, from the pressure signal, a signal segment that comprises a sequence of interference pulses originating from an interference generator associated with the extracorporeal fluid circuit, and a sequence of physiological pulses originating from a physiological pulse generator in a subject which is connected to the extracorporeal fluid circuit; subtracting at least one initial template signal from the signal segment to generate a first difference signal that represents the sequence of interference pulses and residuals of the physiological pulses; processing the first difference signal to generate a first template signal in which the residuals of the physiological pulses are suppressed in relation to the sequence of interference pulses; subtracting at least the first template signal from the signal segment to generate a second difference signal that represents the sequence of physiological pulses and residuals of the interference pulses; processing the second difference signal to generate a second template signal in which the residuals of the interference pulses are suppressed in relation to the sequence of physiological pulses; and evaluating a cardiovascular property of the subject using the second template signal. - View Dependent Claims (25, 31)
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26. A device for processing a pressure signal obtained from a pressure sensor in an extracorporeal fluid circuit, said device comprising:
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segmentation means configured to receive the pressure signal and extract, from the pressure signal, a signal segment that comprises a sequence of interference pulses originating from an interference generator associated with the extracorporeal fluid circuit and a sequence of physiological pulses originating from a physiological pulse generator in a subject which is connected to the extracorporeal fluid circuit; first subtraction means configured to subtract at least one initial template signal from the signal segment to generate a first difference signal that represents the sequence of interference pulses and residuals of the physiological pulses; first refinement means configured to process the first difference signal to generate a first template signal in which the residuals of the physiological pulses are suppressed in relation to the sequence of interference pulses; second subtraction means configured to subtract at least the first template signal from the signal segment to generate a second difference signal that represents the sequence of physiological pulses and residuals of the interference pulses; second refinement means configured to process the second difference signal to generate a second template signal in which the residuals of the interference pulses are suppressed in relation to the sequence of physiological pulses; and evaluation means configured to evaluate a cardiovascular property of the subject using the second template signal. - View Dependent Claims (32)
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Specification