Management of condensate water in oxygenator of extracorporeal membrane oxygenator

Abstract

The present disclosure relates to a method for managing condensate water accumulation in a purge gas flow path of an oxygenator (21) in an extracorporeal membrane oxygenator [ECMO] device (5). The method comprises the steps of: monitoring a purge gas flow and / or a purge gas pressure within the purge gas flow path; when a purification condition is satisfied is determined based on the monitored purge gas flow and / or pressure, and a water purification operation is performed when the purification condition is satisfied. The water purification operation includes one or more of the following: enabling an automatic purification function of the ECMO device (5) for automatically purifying the purge gas flow path by generating a purge purge gas flow through the purge gas flow path; presenting to an operator of the ECMO device (5) a suggestion to enable an automatic purge function of the ECMO device (5); presenting to an operator of the ECMO device (5) a suggestion to manually purge the purge gas flow path, and; an alert indicative of water accumulation in the purge gas flow path is generated.

Description

Technical Field

[0001] The present disclosure relates to the field of extracorporeal blood gas exchange, and in particular to systems, methods, and computer programs for managing condensed water accumulation in a purge gas flow path of an oxygenator in an extracorporeal membrane oxygenator (ECMO) device. Background Art

[0002] When administering therapy to a patient being treated with an extracorporeal membrane oxygenator (ECMO), the oxygenator is supplied with a purge gas flow. The flow includes a gas mixture of one or more of oxygen, air, and carbon dioxide.

[0003] As described in U.S. Patent Application No. 8,585,968, when a conventional oxygenator is used, water vapor from the patient's blood can permeate the hollow fiber membranes and condense in the pores of the membranes. This condensation actually reduces the gas exchange efficiency of the oxygenator.

[0004] In order to remove condensed water in the oxygenator, the "coughing" or "sneezing" of the oxygenator has been suggested as a method to increase the instantaneous flow through the oxygenator, thereby achieving a purge (removal of accumulated moisture) similar to a cough or sneeze of the patient. However, this method has limitations. Since the coughing of the oxygenator increases the pressure of the purge gas compartment (i.e., the lumen of the hollow fiber), the risk of gas embolism forming in the blood and gas embolism flowing back to the patient is significantly increased.

[0005] Therefore, when the oxygenator coughs, the increased pressure of the purge gas in the hollow fibers should never exceed the pressure in the blood compartment (typically less than 200 mmHg). However, because positive pressure is used to increase the purge gas pressure to produce the "cough", it is often difficult, if not impossible, to prevent the purge gas pressure from becoming higher than the pressure in the blood compartment of the oxygenator.

[0006] Therefore, there is a need to improve the management of condensate in ECMO. Summary of the invention

[0007] An object of the present disclosure is to mitigate, alleviate or eliminate one or more of the above-mentioned deficiencies and disadvantages in the prior art and to at least solve the above-mentioned problems.

[0008] According to a first aspect of the present disclosure, a method for managing condensed water accumulation in a purge gas flow path of an oxygenator in an extracorporeal membrane oxygenator (ECMO) device is provided. The method comprises the following steps: monitoring a purge gas flow rate and / or a purge gas pressure within the purge gas flow path; determining when a purge condition is met based on the monitored purge gas flow rate and / or pressure; and performing a water purge operation when the purge condition is met. The water purge operation comprises one or more of the following steps:

[0009] - enabling an automatic purge function of the ECMO device for automatically purging the purge gas flow path by generating a purge gas flow through the purge gas flow path,

[0010] - presenting a recommendation to the operator of the ECMO device to enable an automatic purge function of the ECMO device,

[0011] - presenting a recommendation to the operator of the ECMO device to manually purge the purge gas flow path, and

[0012] - Generates an alarm indicating water accumulation in the purge gas flow path.

[0013] According to some embodiments, the method comprises the step of determining a monitored purge gas flow variability and / or a monitored pressure variability indicative of a purge gas flow path resistance variation, wherein the purge condition is a condition for the purge gas flow variability and / or the pressure variability.

[0014] According to some embodiments, the purge condition is met when a threshold for monitoring pressure changes is exceeded at a substantially constant purge gas flow rate.

[0015] According to some embodiments, the method comprises the step of determining a purge gas flow path resistance based on the monitored purge gas flow rate and / or purge gas pressure, wherein the purge condition is a condition for the purge gas flow path resistance.

[0016] Thus, according to some embodiments, the method comprises the following steps:

[0017] - determining the purge condition as the condition for the monitored purge gas flow path resistance;

[0018] - monitoring the purge gas flow rate and the purge gas pressure within the purge gas flow path;

[0019] - determining a monitored purge gas flow path resistance based on the monitored purge gas flow rate and the purge gas pressure;

[0020] - determining when purge conditions are met based on the monitored purge gas flow path resistance, and

[0021] - Perform water purification operation when purification conditions are met,

[0022] Among them, water purification operations include:

[0023] o enabling an auto-purge function of the ECMO device 5 for automatically purging the purge gas flow path by generating a purge gas flow through the purge gas flow path, or

[0024] Those

[0025] o presenting a recommendation to the operator of the ECMO device 5 to enable the automatic purge function of the ECMO device 5, or

[0026] o presenting a suggestion to the operator of the ECMO device 5 to manually purge the purge gas flow path, or

[0027] o Generates an alarm indicating water accumulation in the purge gas flow path.

[0028] Although the purge gas flow rate and purge gas pressure may vary over time due to manual or automatic changes in ECMO device settings, the purge gas flow path resistance should remain substantially constant unless there is accumulation of condensed water or other material in the purge gas flow path. Thus, using the purge gas flow path resistance as a purge condition provides a more reliable and robust purge operation than a purge operation triggered by changes in purge gas pressure and / or flow rate.

[0029] According to some embodiments, the purification condition is a condition for the variability of the monitored purge gas flow path resistance, wherein the method comprises the steps of determining the variability of the monitored purge gas flow path resistance over time, and performing a water purification operation when the variability of the monitored purge gas flow path resistance satisfies the purification condition.

[0030] The purge condition for the variability of the monitored purge gas flow path resistance may, for example, be a threshold for a change in the monitored purge gas flow resistance. In some examples, the purge condition may be a maximum threshold for the monitored purge gas flow path resistance. The purge condition may be considered satisfied when the monitored purge gas flow path resistance exceeds the maximum threshold, or when the monitored purge gas flow path resistance has exceeded the maximum threshold for a predetermined period of time. The purge condition may be considered satisfied when the monitored purge gas flow path resistance has exceeded the maximum threshold for a predetermined period of time. This may be advantageous in the case of rapid fluctuations in purge gas flow rate and / or purge gas pressure, as such fluctuations may introduce short-term errors in the calculation of the purge gas flow path resistance.

[0031] The purge condition can be determined based on the monitored purge gas flow and the monitored purge gas pressure monitored during a period of time constituting a time period for determining the purge condition. The time period for determining the purge condition is advantageously a period of time during which the purge gas flow path can be considered to contain a minimum water content. For example, the time period for determining the purge condition can occur immediately after the ECMO device is started, when the hoses, membranes, and gas compartments constituting the purge gas flow path of the ECMO device are free of condensed water.

[0032] Alternatively, in some embodiments, the purge conditions can be determined based on an estimated purge gas flow path resistance, which is estimated based on the configuration of the ECMO device. ECMO systems using the same or similar oxygenators and the same or similar purge gas inlet line and purge gas outlet line configurations can be considered to exhibit the same or similar purge gas flow path resistance. Therefore, in some cases, it may be sufficient to set the purge conditions based on a baseline purge gas flow path resistance for the particular type of ECMO system being used.

[0033] According to some embodiments, the purge gas flow is at least 10 l / min.

[0034] According to another aspect of the present disclosure, a computer program for preventing condensed water accumulation in a purge gas flow path of an oxygenator is provided. The computer program includes computer readable instructions that, when executed by a control computer, cause the above method to be performed.

[0035] According to another aspect of the present disclosure, a computer program product is provided, the computer program product comprising a non-transitory storage hardware device storing the above-mentioned computer program.

[0036] According to another aspect of the present disclosure, a system for preventing condensed water accumulation in a purge gas flow path of an oxygenator is provided. The system includes an ECMO device for extracorporeal blood gas exchange, wherein the ECMO device includes: an oxygenator, the oxygenator including a membrane serving as a gas-liquid barrier, the membrane enabling gas exchange between a blood flow through the oxygenator and a purge gas flow; a purge gas flow path, the purge gas flow path including at least a purge gas inlet line for conveying purge gas toward the membrane and a purge gas outlet line for conveying purge gas away from the membrane; at least one flow sensor and / or at least one pressure sensor, at least one flow sensor for measuring a purge gas flow rate within the purge gas flow path, and at least one pressure sensor for measuring a purge gas pressure within the purge gas flow path. The system also includes at least one control computer included in or coupled to the ECMO device, wherein the control computer is configured to: monitor a purge gas flow rate measured by at least one flow sensor and / or a purge gas pressure measured by at least one pressure sensor; determine when a purge condition is met based on the monitored purge gas flow rate and / or purge gas pressure; and perform a water purge operation when the purge condition is met. The water purge operation includes one or more of the following steps:

[0037] - enabling an automatic purge function of the ECMO device for automatically purging the purge gas flow path by generating a purge gas flow through the purge gas flow path,

[0038] - presenting a recommendation to the operator of the ECMO device to enable an automatic purge function of the ECMO device,

[0039] - presenting a recommendation to the operator of the ECMO device to manually purge the purge gas flow path, and

[0040] - Generates an alarm indicating water accumulation in the purge gas flow path.

[0041] According to some embodiments, the control computer is configured to determine a monitored purge gas flow variability and / or a monitored pressure variability indicative of a change in purge gas flow path resistance, wherein the purge condition is a condition for the variability of the purge gas flow rate and / or the variability of the pressure.

[0042] According to some embodiments, the control computer is configured to determine that the purge condition is met when a threshold for monitoring pressure changes is exceeded at a substantially constant purge gas flow rate.

[0043] According to some embodiments, the control computer is configured to determine a purge gas flow path resistance based on the monitored purge gas flow rate and / or purge gas pressure, wherein the purge condition is a condition for the purge gas flow path resistance.

[0044] Thus, according to some embodiments, the system comprises:

[0045] - Extracorporeal membrane oxygenator [ECMO] device 5, the ECMO device 5 is used for extracorporeal blood gas exchange, the ECMO device 5 comprises:

[0046] o an oxygenator 21 comprising a membrane 23 acting as a gas-liquid barrier enabling gas exchange between the blood flow through the oxygenator 21 and the purge gas flow,

[0047] o a purge gas flow path comprising at least a purge gas inlet line 33a for conveying purge gas towards the membrane 23 and a purge gas outlet line 33b for conveying purge gas away from the membrane 23,

[0048] o at least one flow sensor 29a, 31a and / or at least one pressure sensor 29d, wherein the at least one flow sensor 29a, 31a is used to measure the purge gas flow rate in the purge gas flow path, and the at least one pressure sensor 29d is used to measure the purge gas pressure in the purge gas flow path, and

[0049] at least one control computer 27 included in the ECMO device 5 or connected to the ECMO device 5,

[0050] Wherein, the control computer 27 is configured as follows:

[0051] o Determine the purge condition as the condition of the purge gas flow path resistance to be monitored;

[0052] o monitoring the purge gas flow rate measured by at least one flow sensor 29a, 31a and the purge gas pressure measured by at least one pressure sensor 29d;

[0053] ○ Determine the monitored purge based on the monitored purge gas flow and purge gas pressure

[0054] Gas flow path resistance;

[0055] o determine when purge conditions are met based on monitored purge gas flow path resistance, and

[0056] ○When the purification conditions are met, the water purification operation is performed.

[0057] Among them, water purification operations include:

[0058] o enabling an auto-purge function of the ECMO device 5 for automatically purging the purge gas flow path by generating a purge gas flow through the purge gas flow path, or

[0059] Those

[0060] o presenting a recommendation to the operator of the ECMO device to enable the automatic purge function of the ECMO device 5, or

[0061] o Present a recommendation to the operator of the ECMO device to manually purge the purge gas flow path, or

[0062] o Generates an alarm indicating water accumulation in the purge gas flow path.

[0063] According to some embodiments, the purification condition is a condition for the variability of the monitored purge gas flow path resistance, wherein the control computer is configured to: determine the variability of the monitored purge gas flow path resistance over time; and perform a water purification operation when the variability of the monitored purge gas flow path resistance satisfies the purification condition.

[0064] According to some embodiments, the control computer is configured to determine the purge condition based on a monitored purge gas flow rate and a monitored purge gas pressure monitored during a period of time constituting a time period for the purge condition determination.

[0065] As discussed above, the purge condition for the variability of the monitored purge gas flow path resistance may be, for example, a threshold for a change in the monitored purge gas flow resistance. In some examples, the purge condition may be a maximum threshold for the monitored purge gas flow path resistance. The control computer may be configured to determine that the purge condition is met when the monitored purge gas flow path resistance exceeds the maximum threshold, or when the monitored purge gas flow path resistance has exceeded the maximum threshold for a predetermined period of time.

[0066] The control computer can be configured to determine the purge condition based on the monitored purge gas flow and the monitored purge gas pressure monitored during a period of time constituting a time period for determining the purge condition. The time period for determining the purge condition is advantageously a period of time during which the purge gas flow path can be considered to contain a minimum water content. For example, the time period for determining the purge condition can occur immediately after the ECMO device is started, when the hoses, membranes, and gas compartments constituting the purge gas flow path of the ECMO device are free of condensed water.

[0067] Alternatively, in some embodiments, the control computer can be configured to determine the purge conditions based on an estimated purge gas flow path resistance, the resistance estimated based on the configuration of the ECMO device.

[0068] According to some embodiments, the ECMO device further comprises a purge gas generator for generating a purge gas flow through the purge gas flow path, and the control computer is configured to control the purge gas generator to generate the purge gas flow when the automatic purge function is enabled.

[0069] According to some embodiments, the purge gas flow is at least 10 l / min.

[0070] According to some embodiments, the control computer is included in the ECMO device. In other embodiments, the control computer is a control computer of the purge gas flow generator. In still other embodiments, the control computer is a control computer of a separate purification device connected to the purge gas flow generator. In this case, when the purification condition is met, the purification device can perform a water purification operation by sending a signal to the purge gas flow generator that purification should be performed, thereby enabling the automatic purification function of the ECMO device.

[0071] It should be appreciated, therefore, that the above-described computer program for preventing accumulation of condensed water in the purge gas flow path of an oxygenator may reside in any of the control computer of an ECMO device, the control computer of a purge gas flow generator, or the control computer of a purification device coupled to a purge gas flow generator.

[0072] Therefore, according to another aspect of the present disclosure, there is provided an apparatus comprising a control computer including at least one processor and a data storage medium, such as a non-transitory storage hardware device, storing the above-mentioned computer program, wherein the control computer causes the above-mentioned method to be performed when the computer program is executed by the at least one processor. As can be clearly seen from the foregoing description, the apparatus can be a purge gas flow generator for generating a purge gas flow through a purge gas flow path of an ECMO device, or a purification device connected to such a purge gas flow generator.

[0073] Further advantageous features of the method, computer program and system of the present disclosure will be described in the detailed description below. BRIEF DESCRIPTION OF THE DRAWINGS

[0074] The present invention will be more fully understood through the detailed description and accompanying drawings provided below, which are given by way of non-limiting illustration only. In the different drawings, the same reference numerals correspond to the same elements.

[0075] Figure 1 An exemplary non-limiting embodiment of a combined ECMO and ventilator system for extracorporeal removal of CO 2 from the blood of a patient undergoing mechanical ventilation is illustrated.

[0076] Figure 2 An exemplary non-limiting embodiment of an ECMO device incorporating functionality for managing condensed water in a purge gas flow path of the ECMO device is illustrated. DETAILED DESCRIPTION

[0077] The present disclosure will now be described with reference to the accompanying drawings, in which preferred example embodiments of the present disclosure are shown. However, the present disclosure may be implemented in other forms and should not be construed as being limited to the embodiments disclosed herein. The disclosed embodiments are provided to fully convey the scope of the present disclosure to the skilled person.

[0078] Although the present disclosure relates to a functionality for managing condensate in an oxygenator of an extracorporeal membrane oxygenator (ECMO) device, the functionality will be described below in the context of a combined system, referred to herein as an ECMO ventilation system, comprising a mechanical ventilator and an ECMO device for extracorporeal removal of CO 2 from the blood of a patient 3. However, it should be appreciated that the principles of condensate management in an ECMO device—as disclosed herein—are in no way limited to this particular system setup or the presence of a mechanical ventilator.

[0079] ECMO (Extracorporeal Membrane Oxygenation) is one of several terms used for extracorporeal blood gas exchange, in which blood is pumped outside the body of the patient being treated to a device sometimes called a heart-lung machine, which removes CO2 and returns oxygen-rich blood to the patient. Other terms often used in the art for the same or similar treatments are ECLA (Extracorporeal Lung Assist), ECCO2R (Extracorporeal Removal of CO2), ECLS (Extracorporeal Life Support), and ECGE (Extracorporeal Membrane Gas Exchange), all of which are included in the term ECMO as used herein.

[0080] Figure 1 An ECMO ventilation system 1 is illustrated, comprising a device 5 for extracorporeal removal of CO 2 from the blood of a patient 3 , referred to herein as an ECMO device, and a mechanical ventilator 7 for mechanically ventilating the patient 3 by supplying breathing gases to the patient's lungs.

[0081] The ventilator 7 comprises or is connected to a source of pressurized breathing gas (not shown), which is supplied to the patient 3 via a patient circuit 9. In this example, the patient circuit 9 comprises an inspiratory line 11 for delivering a flow of breathing gas to the patient 3, and an expiratory line 13 for delivering a flow of expiratory gas exhaled by the patient away from the patient. The inspiratory line 11 and the expiratory line 13 are connected to each other via a so-called Y-piece 15, which in turn is connected to the patient 3 via a common line 17.

[0082] The ECMO device 5 is configured to: provide ECMO therapy to the patient 3 by generating an extracorporeal blood flow from the patient 3; oxygenate the blood through extracorporeal blood gas exchange in which CO2 is removed from the extracorporeal blood flow and oxygen (O2) is added to the extracorporeal blood flow; and return the oxygen-rich blood to the patient 3.

[0083] In order to generate blood flow to and from the patient 3, the ECMO device 5 may include a blood flow generator (not shown), typically in the form of one or several rollers, turbines and / or centrifugal pumps. The blood flow generator generates blood flow through a tubing system forming a blood flow channel 19 of the ECMO device 5, where portions of the channel may be heated to maintain a desired temperature of the blood when the blood is returned to the patient 3.

[0084] Blood gas exchange including blood oxygenation and CO2 removal occurs in the membrane oxygenator 21 of the ECMO device 5, in which a purge gas flow containing oxygen interacts with the blood in the blood flow channel 19 via a membrane 23 of the oxygenator 21. The membrane 23 acts as a gas-liquid barrier that is capable of transferring CO2 and O2 content between the blood flow of the oxygenator 21 flowing through the liquid side of the membrane 23 and the purge gas flow of the oxygenator 21 flowing through the gas side of the membrane 23.

[0085] The purge gas flow is generated by a purge gas generator 25 connected to one or more purge gas sources, which typically include one or both of an oxygen source and a compressed air source. According to the principles of the present disclosure, the purge gas generator 25 is also connected to a CO2 source so as to control the degree of CO2 removal on the oxygenator 21 by adding CO2 to the purge gas flow. The purge gas generator 25 is configured to deliver a controllable purge gas composition to the oxygenator 21 at a controllable purge gas flow rate. In clinical practice, the purge gas flow generator is often referred to as a purge gas mixer, a purge gas blender, a gas blender, or an electronic gas blender (EGB).

[0086] The composition and optionally the flow rate of the purge gas generated by the purge gas generator 25 may be automatically controlled by a controller or control computer 27 of the ECMO apparatus 5 based on set target values ​​and sensor data obtained by the various sensors 29, 31 of the ECMO apparatus 5. Specifically, the control computer 27 of the ECMO apparatus 5 may be configured to automatically control the addition of CO2 to a purge gas flow comprising either or both of oxygen and air based on a set target for a measure of CO2 removal by the oxygenator 21.

[0087] Hereinafter, the purge gas flow upstream of the oxygenator 21 (i.e., before the oxygenator from the perspective of the purge gas) will be referred to as the input purge gas flow or the pre-oxygenator purge gas flow, and the purge gas flow downstream of the oxygenator 21 (i.e., after the oxygenator from the perspective of the purge gas) will be referred to as the output purge gas flow or the post-oxygenator purge gas flow. The input purge gas flow flows from the purge gas generator 25 to the oxygenator 21 via the purge gas inlet line 33a of the ECMO device 5, and the output purge gas flow flows from the oxygenator 21 to the atmosphere or to an evacuation or recirculation system via the purge gas outlet line 33b. In most configurations, the ECMO system is an open system, which means that the post-oxygenator purge gas flow is allowed to escape into the surrounding environment. In some cases, particularly when anesthetic agents are added to the purge gas flow, a closed or semi-closed (purge) gas control system can be envisioned, similar to the gas control systems often used in anesthesia machines.

[0088] Likewise, the blood flow upstream of the oxygenator 21 (i.e., before the oxygenator from the perspective of blood flow) may be referred to as input blood flow or pre-oxygenator blood flow hereinafter, and the blood flow downstream of the oxygenator 21 (i.e., after the oxygenator from the perspective of blood flow) may be referred to as output blood flow or post-oxygenator blood flow. The input blood flow flows from the patient 3 to the oxygenator 21 via the blood flow inlet line 19a of the ECMO device 5, and the output blood flow flows from the oxygenator 21 and flows back to the patient 3 via the blood flow outlet line 19b of the ECMO device 5.

[0089] Now refer to Figure 2 , the sensors 29, 31 of the ECMO device 5 may include:

[0090] - A pre-oxygenator flow sensor 29a, which is used to measure the flow rate of the input purge gas flow The pre-oxygenator flow sensor 29a is a mainstream flow sensor, which means that it is configured to measure the flow of the purge gas flowing in the purge gas inlet line 33a. The pre-oxygenator flow measurement obtained by the pre-oxygenator flow sensor 29a occurs at a pre-oxygenator flow measurement point denoted as P1 in the purge gas inlet line 33a.

[0091] - a pre-oxygenator gas analyzer 29b for measuring at least the fraction FCO2 of CO2 in the input purge gas flow 入 . The pre-oxygenator gas analyzer 29b may also be configured to measure the fraction of one or more additional gases selected from the group consisting of oxygen (O2), nitrogen (N2) and anesthetic agents. In this exemplary embodiment, the pre-oxygenator gas analyzer 29b is a so-called sidestream gas analyzer configured to extract a purge gas sample from the purge gas inlet line 33a and measure the fraction of CO2 in the purge gas sample at a pre-oxygenator CO2 measurement point denoted as P2, and optionally, the fraction of at least one additional gas. The pre-oxygenator CO2 measurement point P2 is separated in distance from the pre-oxygenator purge gas flow measurement point P1 by at least the length of the pre-oxygenator sample line 34a. In other embodiments, the pre-oxygenator gas analyzer 29b may be a so-called mainstream gas analyzer configured to measure the fraction of CO2 within the purge gas inlet line 33a, and optionally, the fraction of at least one additional gas. In some embodiments, the pre-oxygenator gas analyzer includes at least a CO2 sensor and an O2 sensor for measuring the fraction of CO2 and O2 in the purge gas sample, respectively. In some embodiments, the CO2 sensor is a non-dispersive infrared (NDIR) CO2 sensor. In some embodiments, the O2 sensor is a paramagnetic or electrochemical O2 sensor.

[0092] - a pre-oxygenator temperature sensor 29c, which is used to measure the temperature T of the input purge gas 入，气体 .

[0093] a pressure sensor 29d for measuring a purge gas circuit pressure P which corresponds substantially to the purge gas pressure in the gas inlet line 33a 气体 .

[0094] - A post-oxygenator flow sensor 31a, which is used to measure the flow rate of the output purge gas flow The post-oxygenator flow sensor 31a is a mainstream flow sensor, which means that it is configured to measure the flow rate of the purge gas flowing in the purge gas outlet line 33b. The post-oxygenator flow measurement obtained by the post-oxygenator flow sensor 31a occurs at a post-oxygenator flow measurement point denoted as P3 in the purge gas outlet line 33b.

[0095] - a post-oxygenator gas analyzer 31b for measuring at least the fraction FCO2 of CO2 in the output purge gas flow 出 . The post-oxygenator gas analyzer 31b may also be configured to measure the fraction of one or more additional gases selected from the group consisting of oxygen (O2), nitrogen (N2) and anesthetic agents. In this exemplary embodiment, the post-oxygenator gas analyzer 31b is a so-called sidestream gas analyzer configured to extract a purge gas sample from the purge gas outlet line 33b and measure the CO2 fraction in the purge gas sample at a post-oxygenator CO2 measurement point denoted as P4, and optionally, the fraction of at least one additional gas. The post-oxygenator CO2 measurement point P4 is separated in distance from the post-oxygenator purge gas flow measurement point P3 by at least the length of the post-oxygenator sample line 34b. In other embodiments, the post-oxygenator gas analyzer 31b may be a so-called mainstream gas analyzer configured to measure the fraction of CO2 within the purge gas outlet line 33b, and optionally, the fraction of at least one additional gas. In some embodiments, the post-oxygenator gas analyzer includes at least a CO2 sensor and an O2 sensor for measuring the fraction of CO2 and O2, respectively, in the purge gas sample. In some embodiments, the CO2 sensor is an IR spectrometer for IR spectroscopy, such as IR absorption spectroscopy. In some embodiments, the O2 sensor is a paramagnetic O2 sensor.

[0096] - A post-oxygenator temperature sensor 31c for measuring the temperature of the output purge gas.

[0097] In some embodiments, the ECMO device 5 may also include or be connected to a pre-oxygenator blood gas analyzer 32 for measuring at least the partial pressure PCO2 of CO2 in the input blood flow. 入 The pre-oxygenator blood gas analyzer 32 can also be configured to measure the partial pressure of O2 in the input blood flow, PO2 入 The pre-oxygenator blood gas analyzer 32 can also be configured to measure the hemoglobin content Hb of the input blood flow. 入In some embodiments, the blood gas analyser 32 is not incorporated into the ECMO apparatus 5, but is arranged to form part of another medical device connected to the ECMO apparatus 5 so that the ECMO apparatus 5 receives measurements obtained by the blood gas analyser. For example, the blood gas analyser may form part of a stand-alone blood gas analyser unit, commonly referred to as a BGA, which is typically used for intermittent blood gas analysis during ECMO therapy.

[0098] In accordance with the principles of the present disclosure, the ECMO device 5 includes functionality for managing condensed water accumulation in the purge gas flow path of the oxygenator 21. The control computer 27 is configured to monitor the purge gas flow measured by at least one flow sensor 29a, 31a and / or the purge gas pressure measured by at least one pressure sensor 29d, and determine when a purge condition is met based on the monitored purge gas flow and / or purge gas pressure. If and when the purge condition is met, the control computer 27 is configured to perform a water purge operation by:

[0099] - enabling an automatic purge function of the ECMO device 5 for automatically purging the purge gas flow path by generating a purge gas flow through the purge gas flow path,

[0100] - presenting a recommendation to the operator of the ECMO device 5 to activate the automatic purge function of the ECMO device 5,

[0101] - presenting a recommendation to the operator of the ECMO device 5 to manually purge the purge gas flow path, and / or

[0102] - Generates an alarm indicating water accumulation in the purge gas flow path.

[0103] Thus, the proposed functionality relies on a pressure and / or flow rate controlled water purge operation, which may include enabling an automatic purge function of the ECMO device 5, or causing other actions to be performed that assist the user in managing condensed water accumulation in the purge gas flow path.

[0104] Automatically performing a water purge operation when pressure and / or flow based criteria are met serves to ensure that a water purge operation is performed only when it is truly necessary to purge the purge gas flow path. This also allows for early detection of reduced gas exchange efficiency of the oxygenator 21, since deterioration in oxygenator performance typically causes changes in purge gas flow and / or pressure.

[0105] The control computer 27 may be configured to determine a monitored variability in purge gas flow and / or a monitored variability in pressure indicative of a change in purge gas flow path resistance, and the purge condition may be a condition for the variability in purge gas flow and / or the variability in pressure. In this way, a purge operation may be enabled in response to a change in purge gas flow resistance caused by condensed water accumulation in the gas flow path.

[0106] The control computer 27 may be configured to determine that the purge condition is met when a threshold for monitoring pressure changes is exceeded at a substantially constant purge gas flow rate. This is advantageous because the pressure drop across the oxygenator 21 at a constant flow rate is a reliable and robust measure of the change in purge gas flow path resistance.

[0107] In some embodiments, the control computer 27 may be configured to determine an actual purge gas flow path resistance based on the monitored purge gas flow rate and the monitored purge gas pressure, and the purge condition may be the condition for the actual purge gas flow path resistance.

[0108] The control computer 27 may also be configured to control the purge gas generator 25 to generate a purge gas flow when the auto-purge function is enabled. For neonatal patients, a smaller purge may be required, but for adult patients the purge gas flow should preferably be at least 10 l / min.

[0109] According to another aspect of the present disclosure, a method for managing condensed water accumulation in a purge gas flow path of an oxygenator 21 in an ECMO device 5 is provided. The method is typically a computer-implemented method executed when at least one processor 37 of a control computer 27 executes a computer program. The computer program includes computer-readable instructions that can be stored in a storage medium, such as a non-transitory hardware storage device 39 of the control computer 27.

[0110] The method may include the following steps: monitoring a purge gas flow rate and / or a purge gas pressure within a purge gas flow path; determining when a purge condition is met based on the monitored purge gas flow rate and / or pressure; and performing a water purge operation when the purge condition is met. The water purge operation includes one or more of the following: enabling an automatic purge function of the ECMO device 5 for automatically purging the purge gas flow path by generating a purge purge gas flow through the purge gas flow path; presenting a suggestion to an operator of the ECMO device 5 to enable the automatic purge function of the ECMO device 5; presenting a suggestion to the operator of the ECMO device 5 to manually purge the purge gas flow path and; generating an alarm indicating water accumulation in the purge gas flow path.

[0111] The method may further include the step of determining a variability of the monitored purge gas flow rate and / or a variability of the monitored pressure indicative of a change in the purge gas flow path resistance, wherein the purge condition is a condition for the variability of the purge gas flow rate and / or the variability of the pressure. In some embodiments, the purge condition is determined to be satisfied when a threshold for the monitored pressure change is exceeded at a substantially constant purge gas flow rate.

[0112] In some embodiments, the method includes the step of determining a purge gas flow path resistance based on the monitored purge gas flow rate and the purge gas pressure, whereby the purge condition may be a condition for the purge gas flow path resistance.

Claims

1. A method for managing condensed water accumulation in a purge gas flow path of an oxygenator (21) in an extracorporeal membrane oxygenator [ECMO] device (5), comprising the steps of: - determining the purge condition as the condition for the monitored purge gas flow path resistance; - monitoring the purge gas flow rate and the purge gas pressure within the purge gas flow path; - determining the monitored purge gas flow path resistance based on the monitored purge gas flow rate and the purge gas pressure; - determining when said purge conditions are met based on said monitored purge gas flow path resistance, and - performing a water purification operation when the purification condition is met, Wherein, the water purification operation includes: o enabling an automatic purge function of the ECMO device (5) for automatically purging the purge gas flow path by generating a purge gas flow through the purge gas flow path, or o presenting a recommendation to an operator of the ECMO device (5) to enable the automatic purge function of the ECMO device (5), or o presenting a recommendation to the operator of the ECMO device (5) to manually purge the purge gas flow path, or o Generate an alarm indicating water accumulation in the purge gas flow path.

2. The method according to claim 1, wherein: The purge condition is a condition for the variability of the monitored purge gas flow path resistance, and the method comprises the following steps: - determining a variability of said monitored purge gas flow path resistance over time, and - performing the water purification operation when the monitored variability of the purge gas flow path resistance satisfies the purification condition.

3. The method according to claim 1 or 2, wherein: The purge condition is determined based on a monitored purge gas flow rate and a monitored purge gas pressure monitored during a period of time constituting a time period for the purge condition determination.

4. The method according to claim 3, wherein: The time period used for purge condition determination is a period of time during which the purge gas flow path can be considered to contain a minimum water content.

5. The method according to claim 4, wherein: The time period for determining the purification conditions is a period of time that occurs substantially immediately after the ECMO device (5) is activated.

6. The method according to claim 1 or 2, wherein: The purge condition is determined based on an estimated purge gas flow path resistance, which is estimated based on the configuration of the ECMO device (5).

7. A method according to any one of the preceding claims, wherein: The purge gas flow is at least 10 l / min.

8. A computer program for managing condensed water accumulation in a purge gas flow path of an oxygenator (21), the computer program comprising computer readable instructions which, when executed by a control computer (27), cause the method according to any one of the preceding claims to be performed.

9. A computer program product comprising a non-transitory storage hardware device (39) storing a computer program for preventing accumulation of condensed water in a purge gas flow path of an oxygenator (21), the computer program comprising computer readable instructions which, when executed by a control computer (27), cause the method according to any one of claims 1 to 6 to be performed.

10. A system for managing condensed water accumulation in a purge gas flow path of an oxygenator (21), the system comprising: - an extracorporeal membrane oxygenator [ECMO] device (5), the ECMO device (5) being used for extracorporeal blood gas exchange, the ECMO device (5) comprising: o an oxygenator (21) comprising a membrane (23) acting as a gas-liquid barrier, the membrane (23) enabling gas exchange between a blood flow through the oxygenator (21) and a purge gas flow, a purge gas flow path, the purge gas flow path comprising at least a purge gas inlet line (33a) for conveying purge gas towards the membrane (23) and a purge gas outlet line (33b) for conveying purge gas away from the membrane (23), o at least one flow sensor (29a, 31a) and / or at least one pressure sensor (29d), the at least one flow sensor (29a, 31a) being used to measure the purge gas flow rate in the purge gas flow path, the at least one pressure sensor (29d) being used to measure the purge gas pressure in the purge gas flow path, and - at least one control computer (27), said control computer (27) being included in said ECMO device (5) or being coupled to said ECMO device (5), wherein said control computer (27) is configured to: o Determine the purge condition as the condition of the purge gas flow path resistance to be monitored; o monitoring the purge gas flow rate measured by the at least one flow sensor (29a, 31a) and the purge gas pressure measured by the at least one pressure sensor (29d); o determining the monitored purge gas flow path resistance based on the monitored purge gas flow rate and the purge gas pressure; o determining when the purge conditions are met based on the monitored purge gas flow path resistance, and ○ When the purification conditions are met, a water purification operation is performed, Wherein, the water purification operation includes: o enabling an automatic purge function of the ECMO device (5) for automatically purging the purge gas flow path by generating a purge gas flow through the purge gas flow path, or o presenting a recommendation to an operator of the ECMO device (5) to enable the automatic purge function of the ECMO device (5), or o presenting a recommendation to the operator of the ECMO device (5) to manually purge the purge gas flow path, or o Generate an alarm indicating water accumulation in the purge gas flow path.

11. The system according to claim 10, wherein: The purge condition is a condition for the variability of the monitored purge gas flow path resistance, and the control computer (27) is configured to: - determining a variability of said monitored purge gas flow path resistance over time, and - performing the water purification operation when the monitored variability of the purge gas flow path resistance satisfies the purification condition.

12. The system according to claim 10 or 11, wherein: The control computer (27) is configured to determine the purge condition based on a monitored purge gas flow rate and a monitored purge gas pressure, the monitored purge gas flow rate and the monitored purge gas pressure being monitored during a period of time constituting a time period for purge condition determination.

13. The system according to claim 12, wherein: The time period used for purge condition determination is a period of time during which the purge gas flow path can be considered to contain a minimum water content.

14. The system according to claim 13, wherein: The time period for determining the purification conditions is a period of time that occurs substantially immediately after the ECMO device (5) is activated.

15. The system according to claim 10 or 11, wherein: The control computer (27) is configured to determine the purge condition based on an estimated purge gas flow path resistance, the estimated purge gas flow path resistance being estimated based on a configuration of the ECMO device (5).

16. The system according to any one of claims 10 to 15, wherein: The ECMO device (5) further comprises a purge gas generator (25) for generating a purge gas flow through the purge gas flow path, and the control computer (27) is configured to control the purge gas generator (25) to generate the purge gas flow when the automatic purge function is enabled.

17. A system according to any one of claims 10 to 16, wherein: The purge gas flow is at least 10 l / min.

18. An apparatus comprising a control computer comprising at least one processor and a data storage medium storing a computer program according to claim 8.

19. The device according to claim 18, wherein: The device is a purge gas flow generator (25) for generating a purge gas flow through a purge gas flow path of an ECMO device (5).

20. The device according to claim 18, wherein The device is a purge device connected to a purge gas flow generator for generating a purge gas flow through a purge gas flow path of an ECMO device (5).

21. The device according to any one of claims 18 to 20, wherein: The computer program, when executed by the at least one processor, causes the device to enable an automatic purge function of the ECMO device (5) for automatically purging the purge gas flow path by generating a purge gas flow through the purge gas flow path.

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