Ventilation methods and devices for treating respiratory diseases
Ventilation methods and devices are described. The methods and devices can be used for treating respiratory diseases such as adult respiratory distress syndrome (ARDS). Embedded control software managing various functionalities of the disclosed ventilators is also presented.
1 . A lung ventilator comprising:
a blender, and
a pressure and/or flow regulation section comprising a first pressure regulator and a second pressure regulator;
wherein:
the blender is configured to separately receive oxygen in a regulated oxygen flow from an oxygen source and air in a regulated air flow from an air source, and to blend the oxygen and the air to provide a blended gas;
the pressure and/or flow regulation section is configured to receive the blended gas from the blender and to regulate the blended gas to a first pressure by the first pressure regulator and to a second pressure by the second pressure regulator, the first pressure being a peak inspiratory pressure (PIP) and the second pressure being a positive end-expiratory pressure (PEEP);
the first pressure regulator is an adjustable first pressure regulator and the second pressure regulator is an adjustable second pressure regulator;
the pressure and/or flow regulation section further comprises:
a first selector connected downstream of the first pressure regulator and the second pressure regulator and configured to select and direct the blended gas at the first pressure or at the second pressure; and
a second selector connected downstream of the first selector and in fluid communication therewith, the second selector being configured to receive the selected blended gas and in a transmit state to transmit the selected blended gas downstream of the ventilator and in a block state to block the selected blended gas.
2 . The lung ventilator of claim 1 , wherein the first selector and/or the second selector are a three-way valve.
3 . The lung ventilator of claim 1 , further comprising a selector connection hose connecting the first selector with the second selector.
4 . The lung ventilator of claim 1 , further comprising a control circuit configured to control a state of the first selector and the second selector.
5 . The lung ventilator of claim 4 , further comprising a user interface connected with the control circuit, the user interface comprising:
a plurality of displays to display measured parameter values, and
a plurality of buttons to enter desired parameter values.
6 . The lung ventilator of claim 5 , wherein the blender further comprises a variable orifice adjustable by a button of the plurality of buttons, and wherein during operative conditions the variable orifice is adjusted as a function of the oxygen percentage measured value.
7 . The lung ventilator of claim 5 , wherein during operative conditions, the control circuit is configured to calculate a tidal volume based on an integral of the measured flow rate over an inspiration time, the tidal volume being displayed on a tidal volume display of the plurality of displays.
8 . The lung ventilator of claim 4 , further comprising a static pressure sensor electrically connected to the control circuit and fluidically connected to a point downstream of the second selector with a stagnant flow, the static pressure sensor configured to measure a static pressure during operative conditions.
9 . The lung ventilator of claim 4 , further comprising a plateau pressure sensor electrically connected to the control circuit and configured to be fluidically connected to a detachable patient-specific device, the plateau pressure sensor being configured to measure a plateau pressure during the expiration phase.
10 . The lung ventilator of claim 4 , further comprising embedded software including i) controller software configured to manage the control circuit and ii) panel software to manage the displays.
11 . The lung ventilator of claim 10 , wherein the controller software is configured to interact with the panel software by sending sensed data to the panel software for displaying purposes and by receiving from the panel software operator specified values.
12 . The lung ventilator of claim 11 , wherein the controller software is configured to control the first selector valve and the second selector valve as a function of the sensed data and the operator specified values.
13 . The lung ventilator of claim 1 , wherein the first selector and the second selector each have an independently controllable first state and second state.
14 . The lung ventilator of claim 13 , wherein:
in an inspiration phase, the first and the second selector valves are both in the first state, thereby letting the blended gas at the first pressure (PIP) flow downstream of the ventilator, and
in an expiration phase, the first selector is in the second state and the second selector is in the first state, thereby letting the blended gas at the second pressure (PEEP) flow downstream of the ventilator.
15 . The lung ventilator of claim 13 , wherein the first selector has an independently controllable first state and second state, wherein the first state is a state in which the first selector directs the blended gas at the first pressure (PIP) to the second selector and the second state is a state in which the first selector directs the blended gas at the second pressure (PEEP) to the second selector.
16 . The lung ventilator of claim 1 , further comprising a flow/pressure measurement section placed downstream of the second selector.
17 . The lung ventilator of claim 16 , the flow/pressure measurement section comprising:
a fractional inspired oxygen (FIO 2 ) sensor configured to measure a percentage of inspired oxygen and to generate an oxygen percentage measured value, and
a differential pressure flow sensor configured to measure a flow rate based on a differential pressure measurement and to generate a flow rate measured value.
18 . A lung ventilator comprising:
a blender, and
a pressure and/or flow regulation section comprising a first pressure regulator and a second pressure regulator;
wherein:
the blender is configured to separately receive oxygen in a regulated oxygen flow from an oxygen source and air in a regulated air flow from an air source, and to blend the oxygen and the air to provide a blended gas;
the pressure and/or flow regulation section is configured to receive the blended gas from the blender and to regulate the blended gas to a first pressure by the first pressure regulator, the first pressure being a peak inspiratory pressure (PIP), and to regulate the blended gas to a second pressure by the second pressure regulator, the second pressure being a positive end-expiratory pressure (PEEP);
the pressure and/or flow regulation section further comprises:
a first selector connected downstream of the first pressure regulator and the second pressure regulator and configured to select the blended gas at the first pressure or at the second pressure;
a second selector connected downstream of the first selector;
a selector connection hose fluidically connecting the first selector to the second selector; and
a pilot hose fluidically connected at a first end to the selector connection hose and configured at a second end for connection to a patient-specific device.
19 . The lung ventilator of claim 18 , wherein the second selector is configured to change state from the first state to the second state upon transition from the inspiration phase to the expiration phase, to relieve pressure from the pilot hose by letting extra gas flow out of the lung ventilator.
20 . The lung ventilator of claim 19 , wherein the extra gas flow is let out of the lung ventilator through a bleed orifice of the second selector.