EP-3656430-B1 - MECHANICAL LUNG VENTILATOR

EP3656430B1EP 3656430 B1EP3656430 B1EP 3656430B1EP-3656430-B1

Inventors

BONASSA, JORGE
DE LIMA SANTOS, Adriano
CALVO LONARDONI, José Augusto
COUTINHO MELCO, Tito

Dates

Publication Date: 20260506
Application Date: 20150319

Claims (17)

A ventilator, comprising: a central control unit (2); and a control valve (3), wherein the central control unit (2) is configured to: control, using the control valve (3), a supply of a breathing gas provided to a patient airway connector (10) for a plurality of respiratory cycles; measure, using one or more transducers (5, 6), a volume provided by the ventilator during each of the plurality of respiratory cycles; determine, for each cycle of the plurality of respiratory cycles, a cycle score corresponding to a predetermined deviation band that is representative of a deviation between the measured volume of the cycle and a predetermined target volume, the determined cycle score being selected from a predetermined number of cycle scores that span positive and negative numbers based on the deviation; determine a pressure step value based on the determined cycle scores corresponding to the plurality of respiratory cycles; and adjust, using the control valve (3), a current pressure of the breathing gas by an amount corresponding to the determined pressure step value.
The ventilator of Claim 1, wherein the central control unit (2) is configured to determine each determined cycle score by selecting the cycle score from a predetermined number of cycle scores that span positive and negative numbers based on the deviation, wherein each of the predetermined number of cycle scores is associated with a respective band of deviation.
The ventilator of Claim 1, wherein the plurality of respiratory cycles is a sample size of a larger plurality of respiratory cycles in which the gas is supplied to the airway connector, and wherein the central control unit (2) is configured to determine the pressure step value comprising: generating the pressure step value based on summing the plurality of cycle scores and dividing a result of the summing by the sample size.
The ventilator of Claim 3, wherein the central control unit (2) is configured to determine, for each cycle of the plurality of respiratory cycles, the cycle score based on which range of a first predetermined number of ranges that the respective deviation for the cycle lies within, each range of the first predetermined number of ranges being based on the predetermined target volume.
The ventilator of Claim 4, wherein the central control unit (2) is configured to determine the pressure step value based on which range of a predetermined number of second value ranges that an outcome of the dividing lies within, the predetermined number of second value ranges spanning positive and negative numbers.
The ventilator of Claim 3, wherein the central control unit (2) is configured to calculate a Coefficient of Variation of a test sample size to determine the sample size an equation as follows: CV = Std M , where: a CV= Coefficient of Variation; and Std = ∑ Vt − M 2 Nt − 1 2 , where: Vt = Tidal volume of each cycle; M = Mean of all measured tidal volumes; and Nt = Test sample size (number of cycles).
The ventilator of Claim 6, wherein the central control unit (2) is configured to attribute the sample size based at least partially on the Coefficient of Variation.
The ventilator of Claim 6, wherein the central control unit (2) is configured to attribute the sample size based at least partially on the Coefficient of Variation and on a predetermined category.
The ventilator of Claim 8, wherein the test sample size is predetermined according to the predetermined category, and wherein the predetermined category is one of neonatal, pediatric, or adult.
The ventilator of Claim 1, wherein the central control unit (2) is configured to control the plurality of respiratory cycles by pressure.
The ventilator of Claim 1, wherein a minimum value and a maximum value of the pressure of the gas supplied to the airway connector are user adjustable values.
A system, comprising: a mechanical ventilator device including a control valve (3), the mechanical ventilator device configured to supply a breathing gas to a patient airway connector (10); and a control unit (2) configured to: control the supply of the breathing gas for a plurality of respiratory cycles; measure a volume received by the patient airway connector (10) during each of the plurality of respiratory cycles; determine, for each cycle of the plurality of respiratory cycles, a cycle score corresponding to a predetermined deviation band that is representative of a deviation between the measured volume of the cycle and a predetermined target volume; determine a pressure step value based on the determined cycle scores corresponding to the plurality of respiratory cycles; and adjust, using the control valve (3), a current pressure of the breathing gas by an amount corresponding to the determined pressure step value.
The system of Claim 12, wherein each determined cycle score is determined by selecting the cycle score from a predetermined number of cycle scores that span positive and negative numbers based on the deviation, wherein each of the predetermined number of cycle scores is associated with a respective band of deviation.
The system of Claim 12, wherein the plurality of respiratory cycles is a sample size of a larger plurality of respiratory cycles in which the breathing gas is supplied to the airway of the patient airway connector, and wherein determining the pressure step value comprises: generating the pressure step value based on summing the plurality of cycle scores and dividing a result of the summing by the sample size.
The system of Claim 14, wherein, for each cycle of the plurality of respiratory cycles, the cycle score is determined based on which range of a first predetermined number of ranges that the respective deviation for the cycle lies within, each range of the first predetermined number of ranges being based on the predetermined target volume.
The system of Claim 15, wherein the pressure step value is determined based on which range of a predetermined number of second value ranges that an outcome of the dividing lies within, the predetermined number of second value ranges spanning positive and negative numbers.
A non-transitory machine-readable medium storing instructions thereon to cause the system of any one of claims 12 to 16 to execute steps to perform a method for controlling mechanical ventilation to an airway connector (10), the steps comprising: supplying, using a mechanical ventilator device, a gas to the airway connector (10) for a plurality of respiratory cycles; measuring, by a control unit (2) using one or more transducers (5, 6), a volume received by the airway connector (10) during each of the plurality of respiratory cycles; determining, by the control unit (2), a plurality of cycle scores, including determining, for each cycle of the plurality of respiratory cycles, a cycle score corresponding to a respective predetermined deviation band that is representative of a deviation between the measured volume of the cycle and a predetermined target volume; determining, by the control unit (2), a pressure step value based on the determined plurality of cycle scores corresponding to the plurality of respiratory cycles; and adjusting, by the control unit (2) using a control valve (3), a current pressure of the gas supplied to the airway connector by an amount corresponding to the determined pressure step value.

Description

TECHNICAL FIELD The present disclosure relates to a method for controlling mechanical ventilation to an airway connector, system and ventilator. BACKGROUND A patient requiring lung ventilation support may be connected to a mechanical lung ventilator that applies a positive pressure to insufflate a volume mixture of air and oxygen to the lungs in an intermittent way (in cycles). For example, in an acute respiratory failure condition, the patient is typically sedated or in apnea state. In other words, there may be no spontaneous breathing effort and controlled cycles of mechanical ventilation may be required. Controlled cycles are generally volume or pressure controlled. Volume controlled cycles may have a fixed flow pattern and any variation of the respiratory mechanics may result in pressure change in the patient's airway. On the other hand, pressure controlled cycles generally keep pressure in the patient's airway constant, having free flow demand and, as a result, the volume may be variable. WO 2011/089491 relates to a system for controlling and regulating breathing gas supplied to a patient that includes a pressure generator system that provides breathing gas to a patient and a patent circuit that delivers the breathing gas to the patient. In paragraph [24] it is disclosed that "System 2 measures at least one characteristic of respiratory airflow of the patient; calculates or determines a target time-based parameter, such as an ideal breath rate, based on the at least one measured characteristic; and calculates a target breath-amplitude-based parameter, such as target tidal volume, to be delivered to the patient; and then delivers the calculated target breath-amplitude-based parameter to the patient." SUMMARY The invention is defined by the claims. It is understood that various configurations of the subject technology will become readily apparent to those skilled in the art from the disclosure, wherein various configurations of the subject technology are shown and described by way of illustration. As will be realized, the subject technology is capable of other and different configurations and its several details are capable of modification in various other respects, all without departing from the scope of the subject technology. Accordingly, the summary, drawings and detailed description are to be regarded as illustrative in nature and not as restrictive. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are included to provide further understanding and are incorporated in and constitute a part of this specification, illustrate disclosed embodiments and together with the description serve to explain the principles of the disclosed embodiments. In the drawings: FIG. 1 is a schematic representation of an example of a lung ventilator connected to a patient, in accordance with aspects of the present disclosure.FIG. 2 is a graphical representation of pressure (P) and volume (V) curves for a hypothetic patient in a Pressure Control mode showing a patient's breathing variable pattern classified according to an example method of the present disclosure.FIG. 3 conceptually illustrates an electronic system with which some aspects of the subject technology can be implemented. DETAILED DESCRIPTION The detailed description set forth below describes various configurations of the subject technology and is not intended to represent the only configurations in which the subject technology may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of the subject technology. Accordingly, dimensions are provided in regard to certain aspects as non-limiting examples. However, it will be apparent to those skilled in the art that the subject technology may be practiced without these specific details. In some instances, well-known structures and components are shown in block diagram form in order to avoid obscuring the concepts of the subject technology. It is to be understood that the present disclosure includes examples of the subject technology and does not limit the scope of the appended claims. Various aspects of the subject technology will now be disclosed according to particular but non-limiting examples. Various embodiments described in the present disclosure may be carried out in different ways and variations, and in accordance with a desired application or implementation. Initially, several example scenarios for providing lung ventilation assistance to patients requiring respiratory support will be described to compare and contrast other aspects of the present disclosure. For example, when a patient shows any inspiratory effort, cycles may be synchronized with his/her effort and then are designated as assisted cycles. Nevertheless, in this case, the volume controlled mode, despite being synchronized with the patient's initial effort, may not allow flow synchronism along the cycle, resulting in discomfort for the patient. In contrast, a pres