Respirator and method for determining a fresh gas flow

Patent metadata

Field	Value
Publication number	US-11083859-B2
Application number	US-201514706197-A
Country	US
Kind code	B2
Filing date	May 7, 2015
Priority date	May 8, 2014
Publication date	Aug 10, 2021
Grant date	Aug 10, 2021

Abstract

A respirator (1) includes a fresh gas port (23, 25, 27) for connecting a fresh gas supply, a gas outlet (3) for connecting a supply line for a patient, an absolute pressure sensor (21) and a data processor (37). The gas outlet and the fresh gas port are fluidically connected via an inhalation branch (17) that is connected to the absolute pressure sensor. The fresh gas port has an adjusting valve (31), to set gas flow from the fresh gas supply to the inhalation branch, and a differential pressure sensor (33). The differential pressure sensor determines a differential pressure in the fresh gas port between the inhalation branch and the adjusting valve. The data processor receives and records the absolute pressure measured and the differential pressure to determine a fresh gas flow through the fresh gas port. A method for determining a fresh gas flow is also shown and described.

First claim

What is claimed is:

1. A respirator comprising:
a fresh gas port for connecting a fresh gas supply, the fresh gas port comprising an adjusting valve and a differential pressure sensor;
an inhalation branch, a gas flow from the fresh gas supply to the inhalation branch being set via the adjusting valve, the differential pressure sensor being arranged and configured to measure a differential pressure in the fresh gas port between the inhalation branch and the adjusting valve;
a gas outlet for connecting a supply line for a patient, the gas outlet being connected fluidically with the fresh gas port via the inhalation branch;
an absolute pressure sensor arranged to measure an absolute pressure in the inhalation branch;
a data processor connected with the absolute pressure sensor and connected with the differential pressure sensor to receive and record the absolute pressure measured by the absolute pressure sensor at a plurality of times and to receive and record the differential pressure measured by the differential pressure sensor at a plurality of times, wherein the data processor is configured to determine a fresh gas flow through the fresh gas port at a defined time from the differential pressure measured at the defined time, from the absolute pressure measured at the defined time and from one or more absolute pressures measured at times chronologically preceding the defined time.

2. A respirator in accordance with claim 1 , further comprising at least one additional fresh gas port connected with the gas outlet via the inhalation branch and configured for connecting a fresh gas supply, the at least one additional fresh gas port comprising an adjusting valve and a differential pressure sensor, wherein:
a gas flow from a fresh gas supply connected to the at least one additional fresh gas port to the inhalation branch is set by the at least one additional fresh gas port adjusting valve;
the at least one additional fresh gas port differential pressure sensor is arranged and set up to measure a differential pressure in the at least one additional fresh gas port between the at least one additional fresh gas port adjusting valve and the inhalation branch;
the data processor is connected with the at least one additional fresh gas port differential pressure sensor to receive and record the differential pressure measured by the at least one additional fresh gas port differential pressure sensor at a plurality of times; and
the data processor is configured to determine a fresh gas flow through the at least one additional fresh gas port from the differential pressure measured at the defined time by the at least one additional fresh gas port differential pressure sensor, from the absolute pressure determined at the defined time and from one or more absolute pressures measured at times chronologically preceding the defined time.

3. A respirator in accordance with claim 1 , wherein:
the data processor is configured to determine a mean value of the absolute pressure for each time at which an absolute pressure is measured from absolute pressures measured at a plurality of times chronologically preceding the defined time; and
the data processor is configured to determine the fresh gas flow or fresh gas flows from the mean values of the absolute pressure, which mean values are determined for such times, at which an absolute pressure was measured, which is included in the determination of the fresh gas flow or fresh gas flows.

4. A respirator in accordance with claim 3 , wherein the data processor is configured to determine the fresh gas flow or fresh gas flows from differences of the absolute pressures and of the mean values of the absolute pressure measured and determined for the same times.

5. A respirator in accordance with claim 1 , wherein the data processor is configured to determine a corrected fresh gas flow from a corrected differential pressure, wherein the corrected differential pressure is determined by a transfer function from the measured differential pressure and the absolute pressures influencing the determination of the fresh gas flow.

6. A respirator in accordance with claim 5 , wherein the transfer function has the form of

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Assignees

• Draeger Medical Gmbh
• Draegerwerk Ag & Co Kgaa

Inventors

• Börner Jonas

Classifications

• A61M16/024 Primary

  including calculation means, e.g. using a processor · CPC title

• A61M2205/502

  User interfaces, e.g. screens or keyboards · CPC title

• A61M2205/50

  with microprocessors or computers · CPC title

• A61B5/7203

  for noise prevention, reduction or removal · CPC title

• A61M2016/0027

  pressure meter · CPC title