Filtering of a time-dependent pressure signal
First Claim
1. A device for processing a time-dependent pressure signal obtained from a pressure sensor in a fluid containing system associated with a first pulse generator and a second pulse generator, wherein the pressure sensor is arranged in the fluid containing system to detect first pulses originating from the first pulse generator and second pulses originating from the second pulse generator, wherein the first pulse generator operates in a sequence of pulse cycles, each pulse cycle resulting in at least one first pulse, said device comprising:
- an input for the pressure signal; and
a signal processor connected to said input and configured to;
repetitively obtain a current data sample within a current pulse cycle in the pressure signal;
calculate, for each current data sample within the current pulse cycle, a reference value as a function of a cycle-synchronized data sample in one or more other pulse cycles in the pressure signal, the cycle-synchronized data sample being obtained to have a location in said one or more other pulse cycles that corresponds to a location of the current data sample in the current pulse cycle; and
operate a subtraction algorithm on the current data sample, using said reference value obtained for the current data sample as input, so as to generate a current output sample which is essentially free of a signal component attributable to said at least one first pulse.
1 Assignment
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Accused Products
Abstract
A device removes first pulses in a pressure signal of a pressure sensor which is arranged in a fluid containing system to detect the first pulses, which originate from a first pulse generator, and second pulses, which originate from a second pulse generator. The first pulse generator operates in a sequence of pulse cycles, each pulse cycle resulting in at least one first pulse. The device repetitively obtains a current data sample, calculates a corresponding reference value and subtracts the reference value from the current data sample. The reference value is calculated as a function of other data sample(s) in the same pressure signal. The fluid containing system may include an extracorporeal blood flow circuit, e.g. as part of a dialysis machine, and a cardiovascular system of a human patient.
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Citations
31 Claims
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1. A device for processing a time-dependent pressure signal obtained from a pressure sensor in a fluid containing system associated with a first pulse generator and a second pulse generator, wherein the pressure sensor is arranged in the fluid containing system to detect first pulses originating from the first pulse generator and second pulses originating from the second pulse generator, wherein the first pulse generator operates in a sequence of pulse cycles, each pulse cycle resulting in at least one first pulse, said device comprising:
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an input for the pressure signal; and a signal processor connected to said input and configured to; repetitively obtain a current data sample within a current pulse cycle in the pressure signal; calculate, for each current data sample within the current pulse cycle, a reference value as a function of a cycle-synchronized data sample in one or more other pulse cycles in the pressure signal, the cycle-synchronized data sample being obtained to have a location in said one or more other pulse cycles that corresponds to a location of the current data sample in the current pulse cycle; and operate a subtraction algorithm on the current data sample, using said reference value obtained for the current data sample as input, so as to generate a current output sample which is essentially free of a signal component attributable to said at least one first pulse. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
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25. A device for processing a time-dependent pressure signal obtained from a pressure sensor in a fluid containing system associated with a first pulse generator and a second pulse generator, wherein the pressure sensor is arranged in the fluid containing system to detect first pulses originating from the first pulse generator and second pulses originating from the second pulse generator, wherein the first pulse generator operates in a sequence of pulse cycles, each pulse cycle resulting in at least one first pulse, said device comprising:
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means for repetitively obtaining a current data sample within a current pulse cycle in the pressure signal; means for calculating, for each current data sample in the current pulse cycle, a reference value as a function of a cycle-synchronized data sample in one or more other pulse cycles in the pressure signal, the cycle-synchronized data sample being obtained to have a location in said one or more other pulse cycles that corresponds to a location of the current data sample in the current pulse cycle; and means for operating a subtraction algorithm on the current data sample, using said reference value obtained for the current data sample as input, so as to generate a current output sample which is essentially free of a signal component attributable to said at least one first pulse.
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26. A device for processing a time-dependent pressure signal obtained from a pressure sensor in a fluid containing system associated with a first pulse generator and a second pulse generator, wherein the pressure sensor is arranged in the fluid containing system to detect first pulses originating from the first pulse generator and second pulses originating from the second pulse generator, wherein the first pulse generator operates in a sequence of pulse cycles, each pulse cycle resulting in at least one first pulse, said device comprising:
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an input for the pressure signal; and a signal processor connected to said input and configured to; repetitively obtain a current data sample within the current pulse cycle in the pressure signal; calculate, for each current data sample within the current pulse cycle, a reference value as an estimate of the current data sample, the estimate being calculated by prediction based on at least two data samples in proximity to the current data sample in the pressure signal; and operate a subtraction algorithm on the current data sample, using said reference value obtained for the current data sample as input, so as to generate a current output sample which is essentially free of a signal component attributable to said at least one first pulse. - View Dependent Claims (27, 28)
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29. A device for processing a time-dependent pressure signal obtained from a pressure sensor in a fluid containing system associated with a first pulse generator and a second pulse generator, wherein the pressure sensor is arranged in the fluid containing system to detect first pulses originating from the first pulse generator and second pulses originating from the second pulse generator, wherein the first pulse generator operates in a sequence of pulse cycles, each pulse cycle resulting in at least one first pulse, said device comprising:
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means for repetitively obtaining a current data sample within the current pulse cycle in the pressure signal; means for calculating, for each current data sample within the current pulse cycle, a reference value as an estimate of the current data sample, the estimate being calculated by prediction based on at least two data samples in proximity to the current data sample in the pressure signal; and means for operating a subtraction algorithm on the current data sample, using said reference value obtained for the current data sample as input, so as to generate a current output sample which is essentially free of a signal component attributable to said at least one first pulse.
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30. A method of processing a time-dependent pressure signal obtained from a pressure sensor in a fluid containing system associated with a first pulse generator and a second pulse generator, wherein the pressure sensor is arranged in the fluid containing system to detect first pulses originating from the first pulse generator and second pulses originating from the second pulse generator, wherein the first pulse generator operates in a sequence of pulse cycles, each pulse cycle resulting in at least one first pulse, said method comprising:
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repetitively obtaining a current data sample within a current pulse cycle in the pressure signal; calculating, for each current data sample within the current pulse cycle, a reference value as a function of a cycle-synchronized data sample in one or more other pulse cycles in the pressure signal, the cycle-synchronized data sample being obtained to have a location in said one or more other pulse cycles that corresponds to a location of the current data sample in the current pulse cycle; and operating a subtraction algorithm on the current data sample, using said reference value obtained for the current data sample as input, so as to generate a current output sample which is essentially free of a signal component attributable to said at least one first pulse.
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31. A method of processing a time-dependent pressure signal obtained from a pressure sensor in a fluid containing system associated with a first pulse generator and a second pulse generator, wherein the pressure sensor is arranged in the fluid containing system to detect first pulses originating from the first pulse generator and second pulses originating from the second pulse generator, wherein the first pulse generator operates in a sequence of pulse cycles, each pulse cycle resulting in at least one first pulse, said method comprising:
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repetitively obtaining a current data sample within a current pulse cycle in the pressure signal; calculating, for each current data sample within the current pulse cycle, a reference value as an estimate of the current data sample, the estimate being calculated by prediction based on at least two data samples in proximity to the current data sample in the pressure signal; and operating a subtraction algorithm on the current data sample, using said reference value obtained for the current data sample as input, so as to generate a current output sample which is essentially free of a signal component attributable to said at least one first pulse.
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Specification