Method and device for detecting air in a fluid system, in particular in an extracorporeal blood circuit of a blood treatment device
First Claim
1. A method for detecting the ingress of air into a system for liquid comprising:
- measuring and analyzing a pressure signal in the liquid;
spectrally breaking down the measured pressure signal into at least one function, said at least one function having at least one coefficient;
monitoring the at least one coefficient of the at least one function;
comparing the at least one coefficient of the at least one function to respective preset limiting values; and
determining that there has been an ingress of air into the system for liquid if at least one of the coefficients of the at least one function exceeds or drops below the respective preset limiting values.
1 Assignment
0 Petitions
Accused Products
Abstract
The present invention relates to a method and to a device for detecting the entry of air in a fluid system, in particular in an extracorporeal blood circuit of a blood treatment device comprising an arterial branch leading to the blood treatment unit and a venous branch leading from said blood treatment unit. Periodic fluctuations in the fluid system, in particular in the arterial tube, are measured upstream of the blood pump arranged in said arterial tube. The measured periodic pressure signal is analyzed spectrally in a system of functions, in particular a system of orthogonal functions, for example sine and cosine functions and the entry of air is deduced if at least one of the coefficients of the functions exceeds or falls below predefined threshold values.
-
Citations
29 Claims
-
1. A method for detecting the ingress of air into a system for liquid comprising:
-
measuring and analyzing a pressure signal in the liquid; spectrally breaking down the measured pressure signal into at least one function, said at least one function having at least one coefficient; monitoring the at least one coefficient of the at least one function; comparing the at least one coefficient of the at least one function to respective preset limiting values; and determining that there has been an ingress of air into the system for liquid if at least one of the coefficients of the at least one function exceeds or drops below the respective preset limiting values. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
-
11. A system for detecting the ingress of air into a system for liquid, comprising:
-
means for measuring a pressure signal in the system for liquid; and means for analyzing the measured pressure signal comprising; means for spectrally breaking down the measured pressure signal into at least one function, said at least one function having at least one coefficient; and means for monitoring the at least one coefficient of the at least one function and comparing the at least one coefficient to respective preset limiting values, configured such that an ingress of air into the system for liquid is determined if at least one of the coefficients of the at least one function exceeds or drops below the respective preset limiting values. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19)
-
-
20. An extra-corporeal blood-treating apparatus comprising:
- an extra-corporeal blood circuit which has an arterial segment leading to a blood-treating unit and a venous segment leading from the blood-treating unit, wherein the blood-treating apparatus has a system for detecting the ingress of air into the extra-corporeal blood circuit comprising;
means for measuring a pressure signal in the system for liquid; and means for analyzing the measured pressure signal comprising; means for spectrally breaking down the measured pressure signal measured into at least one function, said at least one function having at least one coefficient; means for monitoring the at least one coefficient of the at least one function and comparing the at least one coefficient to respective preset limiting values, configured such that an ingress of air into the system for liquid is determined if at least one of the coefficients of the at least one function exceeds or drops below the respective preset limiting values.
- an extra-corporeal blood circuit which has an arterial segment leading to a blood-treating unit and a venous segment leading from the blood-treating unit, wherein the blood-treating apparatus has a system for detecting the ingress of air into the extra-corporeal blood circuit comprising;
-
21. A system for detecting the ingress of air into a system for liquid, comprising:
-
a measurement system configured to measure a pressure signal in the system for liquid; and an analysis system configured to analyze the measured pressure signal comprising; a function system configured to spectrally break down the measured pressure signal into at least one function, said at least one function having at least one coefficient; and a monitoring system configured to monitor the at least one coefficient of the at least one function and compare the at least one coefficient to respective preset limiting values, wherein the monitoring system is configured such that an ingress of air into the system for liquid is determined if at least one of the coefficients of the at least one function exceeds or drops below the respective preset limiting values. - View Dependent Claims (22, 23, 24, 25, 26, 27, 28, 29)
-
Specification