DEVICE AND PROCESS FOR BREATH-SUPPORTING RESPIRATION

• US 20070062530A1
• Filed: 07/31/2006
• Published: 03/22/2007
• Est. Priority Date: 09/22/2005
• Status: Active Grant

• Current Assignee: Dragerwerk AG & Company KGaA (FPS Vermögensverwaltung GmbH)
• Original Assignee: Drager Medical AG & Co KG (Dragerwerk AG)
• Inventors: HOPERMANN, Hermann, WEISMANN, Dieter
• Granted Patent: US 7,798,145 B2
• Time in Patent Office: Days
• US Class Current: 128/204.220
• CPC Class Codes: A61M 16/024 including calculation means, e.g. using a processor
• CPC Class Codes: A61M 16/12 by mixing different gases
• CPC Class Codes: A61M 2016/0021 with a proportional output signal, e.g. from a thermistor
• CPC Class Codes: A61M 2016/0042 in the expiratory circuit

Abstract

A respirator for breath-supporting respiration has improved sensitivity of triggering breathing support. A pre-inspiratory inspiratory gas flow is set, which flows off via the expiration valve (9). The closing pressure p_v of the expiration valve is measured with a pressure sensor (11) in the process. The gas flow is increased in case of an inspiratory effort of the patient to the extent that the closing pressure p_v of the expiration valve (9) is restored. Breath support is generated when the difference between the preset gas flow and the gas flow that is needed to maintain the closing pressure p_v at a constant level exceeds a predetermined threshold value.

Claims

1. A device for breath-supporting respiration, the device comprising:

a breathing gas source;

an expiration valve;

an inspiration line from said breathing gas source to a patient;

an expiration line from the patient to said expiration valve;

a feed means for feeding breathing gas, which is arranged downstream of said breathing gas source and can be actuated;

a flow sensor for sensing flow in said expiration line, and for supplying a measured breathing gas flow value dV_em/dt;

a pressure sensor for determining a breathing gas pressure measured value p_vm on the incoming flow side of said expiration valve;

a first control for setting an expiration valve closing pressure p_v from said measured breathing gas flow value dV_em/dt and said breathing gas pressure measured value p_vm according to the presetting of a pressure set point;

a second control forming a control loop with said feed means as a final control element, said second control setting a gas flow for determining the expiration valve closing pressure p_v according to the presetting of a set point for a pre-inspiratory inspiratory gas flow dV_emin/dt with said breathing gas measured flow value dV_em/dt as the actual value; and

a control means for generating breathing support when the pre-inspiratory gas flow dV_isoll/dt necessary for maintaining the closing pressure p_v exceeds a preset threshold value.

2. A device in accordance with claim 1, wherein said first control integrates an internal resistance of said expiration valve in the setting of said closing pressure p_v.

3. A device in accordance with claim 1, wherein said control means generates breathing support when a difference between the preset set point for said pre-inspiratory inspiratory gas flow dV_emin/dt and said gas flow dV_isoll/dt necessary for maintaining said closing pressure p_v exceeds a present threshold value.

4. A process for controlling a respirator, the process comprising:

providing a breathing gas source;

providing an expiration valve;

providing an inspiration line from the breathing gas source to a patient;

providing an expiration line from the patient to the expiration valve;

providing a feed means arranged downstream of the breathing gas source with the feed means being actuatable;

providing a flow sensor sensing flow in the expiration line;

providing a pressure sensor sensing pressure on the incoming flow side of the expiration valve;

setting of a pre-inspiratory gas flow, corresponding to a presetting of a set point, dV_emin/dt;

allowing the flow to flow off via the expiration valve at a preset closing pressure p_v;

measuring the closing pressure p_v as a measured pressure valve p_vm with the pressure sensor;

increasing the gas flow with the feed means when the measured pressure value p_v drops because of an inspiration effort on the part of the patient until the preset closing pressure p_v is restored; and

generating breath support with a control means when the pre-inspiratory gas flow dV_isoll/dt necessary to maintain the closing pressure p_v exceeds a preset threshold value.

5. A process in accordance with claim 4, wherein breath support is generated when the difference between the preset set point for the pre-inspiratory inspiratory gas flow dV_emin/dt and the gas flow dV_isoll/dt necessary to maintain the closing pressure p_v exceeds a preset threshold value.