System and method for metabolic measurements

Abstract

The present disclosure relates to a system for metabolic measurements, the system comprising: a metabolic monitor configured to determine a first concentration measurement of O2 and CO2 in a portion of exhaled breath exhaled by a subject during one or more breaths; and determine a first O2 consumption rate (VO2) and a first CO2 volume production (VCO2) of the subject during the one or more breaths based on the determined first O2 concentration and the determined first CO2 concentration; a CO2 monitor configured to determine a second CO2 concentration measurement in the exhaled breath during one or more breaths; and determine a second CO2 volume production (VCO2) of the subject based on the measured second CO2 concentration; and a processor configured to determine a correction factor based on the determined first VCO2 and second VCO2; and determine a corrected first VO2 using the correction factor and the first VO2.

Description

Technical Field

[0001] This disclosure relates to systems and methods for metabolic measurements. Background Technology

[0002] Metabolic monitoring devices are commonly used to assess the energy expenditure of a particular subject. However, such systems can be cumbersome and / or lack accuracy. Insufficient energy intake (e.g., during ICU stays) may increase morbidity, while excessive intake may lead to hyperglycemia, high carbon dioxide production (which can have potentially harmful effects in subjects with impaired respiratory function or respiratory failure), dyslipidemia, and / or hepatic steatosis. This invention overcomes the deficiencies of existing systems. Summary of the Invention

[0003] Therefore, one or more aspects of this disclosure relate to systems. This disclosure relates to a system for metabolic measurements, the system comprising: a metabolic monitor configured to determine first concentration measurements of O2 and CO2 in a portion of the exhaled air by a subject during one or more breaths; and to determine a first O2 consumption rate (VO2) and a first CO2 volumetric output (VCO2) during one or more breaths based on the determined first O2 concentration and the determined first CO2 concentration in the exhaled air; a CO2 monitor configured to determine a second CO2 concentration measurement in the exhaled air by a subject during one or more breaths; and to determine a second CO2 volumetric output (VCO2) during one or more breaths based on the measured second CO2 concentration; and one or more physical computer processors operatively connected to a plurality of sensors, the metabolic monitor, and the CO2 monitor, the one or more physical computer processors being configured by computer-readable instructions to determine a correction factor based on the determined first VCO2 and second VCO2; and to determine a corrected first VO2 using the correction factor and the first VO2.

[0004] Another aspect of this disclosure relates to a method comprising: using a metabolic monitor to determine first concentration measurements of O2 and CO2 in a portion of the exhaled air by a subject during one or more breaths; using the metabolic monitor, determining a first O2 consumption rate (VO2) and a first CO2 volumetric production (VCO2) of the subject during one or more breaths based on the determined first O2 concentration and the determined first CO2 concentration in the exhaled air; using a CO2 monitor to determine a second CO2 concentration measurement in the exhaled air by the subject during one or more breaths; using the CO2 monitor, determining a second CO2 production (VCO2) of the subject during one or more breaths based on the measured second CO2 concentration; using one or more physical computer processors to determine a correction factor based on the determined first VCO2 and second VCO2; and using one or more physical computer processors to determine a corrected first VO2 using the correction factor and the first VO2.

[0005] Another aspect of this disclosure relates to a system for metabolic measurements. The system includes: means for determining first concentration measurements of O2 and CO2 in a portion of the gas exhaled by a subject during one or more breaths; means for determining a first O2 consumption rate (VO2) and a first CO2 volumetric output (VCO2) of the subject during one or more breaths based on the determined first O2 concentration and the determined first CO2 concentration in the portion of the exhaled gas; means for determining a second CO2 concentration measurement in the gas exhaled by the subject during one or more breaths; means for determining a second CO2 volumetric output (VCO2) of the subject during one or more breaths based on the measured second CO2 concentration; means for determining a correction factor based on the determined first VCO2 and second VCO2; and means for determining a corrected first VO2 using the correction factor and the first VO2.

[0006] These and other objects, features, and characteristics of this disclosure, as well as the methods of operation and function of related elements of the structure, and the economy of combination and manufacture of components, will become more apparent by considering the following description and appended claims with reference to the accompanying drawings, all of which are a part of this specification, wherein the same reference numerals denote corresponding components in the various drawings. However, it should be clearly understood that the drawings are for illustrative and descriptive purposes only and are not intended to be limiting of this disclosure. Attached Figure Description

[0007] Figure 1 This is a schematic diagram of a system configured to determine metabolic measurements according to one or more embodiments;

[0008] Figure 2The illustration shows a schematic diagram of a model configured to determine metabolic measurements according to one or more embodiments;

[0009] Figure 3 The illustration shows examples of curves representing different VCO2 measurements according to one or more embodiments;

[0010] Figure 4 The illustration shows examples of curves representing different VCO2 measurements according to one or more embodiments;

[0011] Figure 5 The illustration shows examples of curves representing different VO2 measurements according to one or more embodiments;

[0012] Figure 6 The illustration shows a method for determining a correction factor for a metabolic measurement according to one or more embodiments. Detailed Implementation

[0013] Unless the context clearly indicates otherwise, as used herein, the singular forms “a,” “an,” and “the” include plural references. Unless the context clearly indicates otherwise, as used herein, the term “or” means “and / or.” As used herein, the expression “coupled” means that these parts or components are directly or indirectly (i.e., by means of one or more intermediate parts or components) connected or operating together, provided a link exists. As used herein, “direct coupling” means that two elements are in direct contact with each other. As used herein, “fixedly coupled” or “fixed” means that two components are coupled to move as one component while maintaining a constant orientation relative to each other.

[0014] As used herein, the term “monolithic” means that an assembly is created as a single piece or unit. That is, an assembly comprising parts manufactured separately and then coupled together as units is not a “monolithic” assembly or body. As used herein, the expression “jointly” of two or more parts or components means that the parts apply forces to each other directly or by means of one or more intermediate parts or components. As used herein, the term “quantity” means an integer of one or more (i.e., a plurality).

[0015] Directional phrases used herein (such as, for example but not limited to, top, bottom, left, right, up, down, front, back, and their derivatives) refer to the orientation of the elements shown in the accompanying drawings and do not limit the claims unless expressly stated herein.

[0016] In clinical practice (e.g., in the Intensive Care Unit (ICU), patients often do not receive sufficient calories. Excessive low-calorie or high-calorie feeding should generally be avoided. Specifically, during ICU stays, insufficient energy intake, increased morbidity, and overfeeding can lead to hyperglycemia, high carbon dioxide production (which can be detrimental in patients with impaired respiratory function or respiratory failure), dyslipidemia, and / or hepatic steatosis. Current methods use expensive and bulky metabolic monitoring equipment to assess a patient's specific energy expenditure. Typically, metabolic monitoring equipment has a mixing chamber in which gases from the patient are analyzed based on carbon dioxide and oxygen concentrations to estimate carbon dioxide production (VCO2), oxygen consumption (VO2), and thus the metabolic needs of that particular patient. In some embodiments, oxygen consumption can be determined as volumetric O2 consumption and / or mass O2 consumption. Because of the use of sensors in a large mixing chamber, estimating oxygen consumption can take longer to achieve a reliable measurement. To estimate the carbon dioxide produced by the patient, a CO2 monitor (e.g., a carbon dioxide charger) is typically used.

[0017] Smaller metabolic monitors with smaller mixing chambers may exist. They are able to have smaller mixing chambers because they continuously sample the percentage of respiratory flow. However, measurements from these monitors can be inaccurate due to the proportional flow sampling (it can be difficult to sample a precise, fixed percentage of flow when the flow rate is not constant during respiration). Typically, at higher flow rates, actual sampling exceeds the design value, while at lower flow rates, actual sampling falls below the design value. Due to this inaccuracy, the mixing chamber will sample more gas in the initial phase of respiration, when the flow rate is at its maximum. This portion of respiration is characterized by a higher concentration of carbon dioxide. This inaccuracy in sampling can lead to higher CO2 concentrations in the mixing chamber and thus higher CO2 production calculations. The same applies to oxygen consumption calculations.

[0018] System 10 (in) Figure 1The system 10 (described in the text) overcomes the shortcomings of existing systems. It leverages the reliability and accuracy of VCO2 measurements from a CO2 monitor, which are unaffected by scaled sampling issues because the measurement is performed on the entire flow. In some embodiments, such a CO2 monitor may include a capnograph that monitors the concentration or partial pressure of carbon dioxide (CO2) in the respiratory gas. This measurement, combined with the flow measurement, is used to calculate the carbon dioxide produced by the patient. The CO2 monitor (e.g., the capnograph) does not measure the patient's O2 concentration and O2 consumption. System 10 uses VCO2 measurements from the CO2 monitor to enhance the metabolic monitor measurement. Specifically, system 10 is configured to calculate a correction factor using both the VCO2 measurements from the CO2 monitor and the VCO2 measurements from the metabolic monitor, and to apply this correction factor to the VO2 consumption calculation from the metabolic monitor. This correction factor can be applied to the VO2 measurement from the metabolic monitor. This correction allows for improved accuracy in understanding the vital signs VO2 required to assess a patient's metabolic needs.

[0019] In some embodiments, system 10 includes one or more of the following components: a metabolic monitor 16, a CO2 monitor 17, multiple sensors 18, a processor 20, an electronic storage device 22, multiple client computing platforms 24, a network 26, and / or other components. Figure 1 In this embodiment, the metabolic monitor 16, CO2 monitor 17, (multiple) sensors 18, processor 20, electronic storage device 22, and (multiple) client computing platforms 24 are shown as separate entities. In some embodiments, some and / or all components and / or other components of system 10 may be grouped into one or more individual devices (e.g., user device, metabolic monitor, CO2 monitor, medical device, etc.). In some embodiments, some or all components of system 10 may coexist in the same housing and communicate directly with each other and with the subject. In some embodiments, the metabolic monitor 16, CO2 monitor 17, (multiple) sensors 18, processor 20, and other components of system 10 may communicate with each other via wired or wireless connections. In some embodiments, system 10 may include a subject interface 90 configured to provide breathable gas to the subject and / or collect exhaled gas from the subject. In some embodiments, the subject interface 90 is configured to connect to other components (e.g., metabolic monitor 16, CO2 monitor, sensors, or other components, etc.) within or outside system 10. In some embodiments, the subject interface may be included in the metabolic monitor 16 and / or the CO2 monitor 17.

[0020] The metabolic monitor 16 is configured to provide information about the metabolic status of a subject. In some embodiments, the metabolic monitor 16 is configured to determine first concentration measurements of O2 and CO2 in a portion of the gas exhaled by the subject during one or more breaths. In some embodiments, the metabolic monitor 16 may include one or more sensors 15 configured to output signals relating to one or more gas parameters in the gas inhaled and / or exhaled by the subject. In some embodiments, the sensors 15 may include one or more O2 concentration sensors 13 configured to output signals relating to the O2 concentration in the gas inhaled and / or exhaled by the subject. In some embodiments, the sensors(s)15 include one or more CO2 concentration sensors 11 (e.g., non-dispersive infrared (NDIR) CO2 sensors) configured to output signals relating to the CO2 concentration in the gas exhaled and / or inhaled by the subject. In some embodiments, the sensors (15) may include a flow rate sensor 21 configured to output signals relating to the flow rate of the gas inhaled and / or exhaled by the subject. In some embodiments, the metabolic monitor 16 may include other sensors (e.g., sensor 18 described below). In some embodiments, the metabolic monitor (16) includes a mixing chamber 19 configured to collect all or a portion of exhaled gases. In some embodiments, all exhaled gases enter the mixing chamber where O2 and CO2 are measured. In some embodiments, a certain percentage of the exhaled gases (i.e., a fixed percentage of the total flow at any given time) enters the mixing chamber, while the remainder is released directly into the environment.

[0021] In some embodiments, the metabolic monitor 16 may be configured to determine a first O2 consumption rate (VO2) and a first CO2 volumetric production (VCO2) of a subject during one or more breaths. In some embodiments, the determination of VO2 and / or VCO2 may be based on a determined first O2 concentration and a determined first CO2 concentration in a portion of exhaled gas. In some embodiments, the determination of VO2 and / or VCO2 may be further based on one or more respiratory parameters of the subject. In some embodiments, one or more respiratory parameters may include the flow rate of exhaled gas (e.g., determined by a flow sensor included in sensor 21).

[0022] In some embodiments, the metabolic monitor 16 may be configured to provide information related to the subject's metabolic status based on measurements of oxygen consumption (VO2) and carbon dioxide production (VCO2), and their changes over time. In some embodiments, the VO2 and VCO2 measurements may be used to estimate the subject's energy expenditure (EE) and respiratory quotient (RQ). Energy expenditure (EE) may be used to assess an individual's caloric requirements, while the respiratory quotient (RQ) provides information related to macronutrients primarily used for energy production (e.g., carbohydrates, fats, proteins, etc.). In some embodiments, the metabolic monitor device is a basal metabolic rate (BMR) device, a resting metabolic rate (RMR) device, a resting energy expenditure (REE) device, and / or any device capable of providing the subject's metabolic rate.

[0023] CO2 monitor 17 is configured to provide information relating to CO2 concentration in a measurement of carbon dioxide production (VCO2) in exhaled gas. In some embodiments, CO2 monitor 17 may include one or more sensors 25 configured to output signals relating to one or more gas parameters in the subject's inhaled and / or exhaled gas. In some embodiments, sensor 25 may include one or more CO2 concentration sensors 27 (e.g., nondispersive infrared (NDIR) CO2 sensors) configured to output signals relating to the CO2 concentration in the subject's exhaled and / or inhaled gas. In some embodiments, sensor 25 may include a flow rate sensor 29 configured to output signals relating to the flow rate of the subject's inhaled and / or exhaled gas. In some embodiments, CO2 monitor 17 may include other sensors (e.g., sensor 18 described below). In some embodiments, CO2 monitor 17 may be configured to determine carbon dioxide production (VCO2) based on a CO2 concentration measurement. In some embodiments, VCO2 is also determined based on one or more respiratory parameters of the subject (e.g., the flow rate of exhaled gas). In some embodiments, CO2 monitor 17 may be a carbon dioxide recorder. Other CO2 monitors may be considered.

[0024] In some embodiments, one or more functions of the metabolic monitor 16 and / or CO2 monitor 17 may be performed by the processor 20. In some embodiments, one or more functions of the metabolic monitor 16 and / or CO2 monitor 17 may be performed by a processor included in these devices. In some embodiments, one or more functions of the metabolic monitor 16 and / or CO2 monitor 17 may be performed by a processor external to the system 10.

[0025] Multiple sensors 18 are configured to generate output signals that convey information relating to one or more respiratory parameters of the subject 12, such as during one or more breaths, during one or more time intervals, and / or continuously. In some embodiments, the one or more respiratory parameters may include gas parameters relating to the breathable gas provided to the subject 12, respiratory parameters relating to the subject 12's breathing, physiological parameters of the subject 12, and / or other parameters. The one or more gas parameters relating to the breathable gas may include, for example, one or more of the following: inhalation flow rate, exhalation flow rate, inhalation volume, pressure, humidity, temperature, acceleration, velocity, and / or other parameters. Respiratory parameters relating to the subject 12's breathing may include tidal volume, timing (e.g., the start and / or end of inspiration, the start and / or end of exhalation, etc.), inhalation flow rate, expiratory flow rate, respiratory rate, respiratory airflow, duration (e.g., duration of inspiration, duration of exhalation, duration of respiratory cycle, etc.), respiratory rate, respiratory effort, and / or other respiratory parameters. Physiological parameters may include blood oxygenation parameters, pulse, body temperature, blood pressure, and / or other physiological parameters. In some embodiments, the plurality of sensors 18 may include one or more sensors that directly (e.g., via fluid communication with the subject and / or subject interface) measure such parameters. In some embodiments, the plurality of sensors 18 may include one or more sensors that indirectly (e.g., via measurements from other sensors or other components within or outside the system 10) generate an output signal relating to one or more parameters. In some embodiments, the plurality of sensors 18 may include one or more sensors configured to generate an output signal relating to physiological parameters of the subject 12. Examples include cardiac sensors for measuring cardiac parameters of the subject, motion sensors for detecting the subject's movement, accelerometers, pulse oximeters, audio sensors, video sensors (cameras), and / or other sensors.

[0026] The multiple sensors 18 may include sensors located at multiple locations inside or outside the system 10. For example, in some embodiments, the multiple sensors 18 may be included in the metabolic monitor 16 and / or the CO2 monitor 17. For example, the multiple sensors 18 may include sensors (e.g., cameras) directly coupled to the subject 12 and positioned to point at the subject 12 and / or at other locations.

[0027] Processor 20 is configured to provide information processing capabilities within system 10. Thus, processor 20 may include one or more of the following: a digital processor, an analog processor, digital circuitry designed to process information, analog circuitry designed to process information, a state machine, and / or other mechanisms for electronically processing information. Although processor 20 is... Figure 1The processor 20 is shown as a single entity, but this is for illustrative purposes only. In some embodiments, the processor 20 may include multiple processing units. These processing units may be physically located within the same device (e.g., a server), or the processor 20 may represent the processing capabilities of multiple devices operating in concert (e.g., one or more servers, one or more computing devices 24 associated with a user, medical devices, sensors(s) 18, metabolic monitors, hospital equipment, devices as part of external resource 14, electronic storage devices 22, and / or other devices).

[0028] like Figure 1 As shown, processor 20 is configured to execute one or more computer program components. The one or more computer program components may include one or more of the following: subject information component 28, metabolic monitor component 30, CO2 monitor component 32, correction factor determination component 36, correction component 38, and / or other components. Processor 20 may be configured to execute components 28, 30, 32, 36, 38, and / or other components via software; hardware; firmware; a combination of software, hardware, and / or firmware; and / or other mechanisms for configuring the processing capabilities on processor 20.

[0029] It should be understood that, although Figure 1 Components 28, 30, 32, 36, and 38 are illustrated as co-located within a single processing unit. However, in embodiments where processor 20 includes multiple processing units, one or more of components 28, 30, 32, 36, 38, and / or other components may be located remotely from other components. The description of the functionality provided by the different components 28, 30, 32, 36, 38, and / or other components described below is for illustrative purposes and is not intended to be limiting, as any one of components 28, 30, 32, 36, and / or 38 may provide more or less functionality than described. For example, one or more of components 28, 30, 32, 36, and / or 38 may be removed, and some or all of their functionality may be provided by other components 28, 30, 32, 36, and / or 38. As another example, processor 20 may be configured to execute one or more additional components that may perform some or all of the functionality attributed below to one of components 28, 30, 32, 36, and / or 38.

[0030] In some embodiments, the subject information component 28 may be configured to determine (and / or acquire) information relating to the subject 12. In some embodiments, the subject information component 28 may be configured to determine information relating to the subject's respiratory parameters. In some embodiments, the information relating to the subject's respiratory parameters may be acquired (determined) from the metabolic monitor 16 and / or the CO2 monitor 17. In some embodiments, the respiratory parameter information may include one or more of the following: inhalation flow rate, exhalation flow rate, inhalation volume, pressure, humidity, temperature, acceleration, velocity, concentration of gas components (e.g., O2 concentration, CO2 concentration, etc.) and / or other parameters of breathable gases. Respiratory parameters relating to the breathing of the subject 12 may include tidal volume, timing (e.g., the start and / or end of inspiration, the start and / or end of exhalation, etc.), inhalation flow rate, exhalation flow rate, respiratory rate, respiratory airflow, duration (e.g., duration of inhalation, duration of exhalation, duration of respiratory cycle, etc.), respiratory rate, respiratory effort, concentration of exhaled and inhaled gas components (e.g., O2 concentration, CO2 concentration, etc.) and / or other respiratory parameters. In some embodiments, the subject’s respiratory parameters may be determined based on output signals from sensors(s)18.

[0031] In some embodiments, the information relating to subject 12 may include biometric information. For example, biometric information may include demographic information (e.g., sex, race, age, etc.), vital signs information (e.g., heart rate, body temperature, respiratory rate, weight, BMI, etc.), medical / health status information (e.g., disease type, disease severity, disease stage, disease classification, symptoms, behavior, readmission, relapse, etc.), treatment history information (e.g., type of treatment, duration of treatment, current and past medications, etc.), and / or other information. In some embodiments, subject information component 28 may include information relating to previous respiratory parameters (e.g., previous monitoring sessions and / or previous measurements).

[0032] In some embodiments, the subject information component 28 may be configured to determine (and / or acquire) information relating to other subjects, such as subjects having similar respiratory parameter information, demographic information, vital sign information, medical / health status information, treatment history information, and / or other similarities to subject 12. It should be noted that the subject information described above is not limiting. According to some embodiments, a large amount of information relating to the subject may exist and may be used with system 10. For example, users may select subject data to customize system 10 and include any type of subject data they deem relevant. In some embodiments, the subject information component 28 may be configured to acquire / extract information from one or more databases (e.g., included in electronic storage device 22, external resource 14, one or more medical devices, other internal or external databases, and / or other information sources).

[0033] The metabolic monitoring component 30 can be configured to acquire information from the metabolic monitor 16. In some embodiments, the information from the metabolic monitor may relate to respiratory gas parameters. For example, in some embodiments, the information from the metabolic monitor may include the O2 concentration in the subject's exhaled breath, the CO2 concentration in the subject's exhaled breath, the subject's O2 consumption (VO2), the subject's CO2 volumetric production (VCO2), the flow rate of inhaled / or exhaled gas, and / or other respiratory gas parameters.

[0034] In some embodiments, the metabolic monitoring component 30 is configured to receive, determine, and / or acquire one or more gas parameters (e.g., from components inside or outside the system 10). One or more parameters may be determined based on output signals from the sensor(s)(x)18. In some embodiments, the metabolic monitoring component 30 is configured to determine one or more respiratory parameters related to the breathing of the subject 12, one or more parameters of the breathable gas within the system 10 (e.g., parameters related to the flow rate of the breathable gas delivered by the breathing device), one or more physiological parameters of the subject 12, and / or other parameters. Respiratory parameters related to the breathing of the subject 12 may include the start and / or end of an individual's breathing. In some embodiments, respiratory parameters may include tidal volume, timing (e.g., the start and / or end of inhalation, the start and / or end of exhalation, etc.), respiratory rate, duration (e.g., the duration of inhalation, the duration of exhalation, the duration of a single respiratory cycle, etc.), respiratory flow, respiratory effort, respiratory rate, and / or other respiratory parameters. One or more gas parameters of the breathable flow delivered to the subject may include, for example, flow rate, volume, pressure, humidity, temperature, acceleration, velocity, and / or other gas parameters. Physiological parameters may include blood oxygenation parameters, pulse, body temperature, blood pressure, exercise and / or other physiological parameters.

[0035] In some embodiments, the metabolic monitoring component 30 is configured to determine the flow rate of exhaled gas based on output signals from one or more sensors 18. In some embodiments, the metabolic monitoring component 30 is configured to determine the inspiratory flow rate, expiratory flow rate, and / or other gas flow rates within the interface device. In some embodiments, the entire expiratory flow rate is determined. In some embodiments, the metabolic monitoring component 30 is configured to determine the flow rate of a portion of the exhaled gas. For example, in some embodiments, the exhaled gas is sampled (after all exhaled gas has been collected). For example, in some embodiments, a constant proportion of the sample flow is directed to a mixing chamber for further measurements (e.g., O2 and CO2 concentration measurements). In some embodiments, the metabolic monitoring component 30 is configured to determine the volume of inhaled air and / or the volume of exhaled air.

[0036] CO2 monitoring component 32 can be configured to acquire information from a CO2 monitor. In some embodiments, the information from the CO2 monitor may relate to respiratory gas parameters. For example, in some embodiments, the information from the CO2 monitor may include the CO2 concentration in the subject's exhaled gas, the subject's volumetric CO2 production (VCO2), the flow rate of inhaled / or exhaled gas, and / or other respiratory gas parameters.

[0037] In some embodiments, the CO2 monitoring component 32 may be configured to receive, determine, and / or acquire one or more gas parameters (e.g., from components inside or outside the system 10). In some embodiments, one or more parameters may be determined based on output signals from sensor(s)(x)18. In some embodiments, the CO2 monitoring component 32 is configured to determine one or more respiratory parameters related to the breathing of the subject 12, one or more parameters of the breathable gas within the system 10 (e.g., parameters related to the flow rate of the breathable gas delivered by the breathing device), one or more physiological parameters of the subject 12, and / or other parameters. Respiratory parameters related to the breathing of the subject 12 may include the start and / or end of an individual's breathing. In some embodiments, respiratory parameters may include tidal volume, timing (e.g., the start and / or end of inspiration, the start and / or end of expiration, etc.), respiratory rate, duration (e.g., the duration of inspiration, the duration of expiration, the duration of a single respiratory cycle, etc.), respiratory flow, respiratory effort, respiratory rate, and / or other respiratory parameters. One or more gas parameters of the breathable flow delivered to the subject may include, for example, flow rate, volume, pressure, humidity, temperature, acceleration, velocity, and / or other gas parameters. Physiological parameters may include blood oxygenation parameters, pulse, body temperature, blood pressure, exercise and / or other physiological parameters.

[0038] In some embodiments, the CO2 monitoring component 32 is configured to determine the exhaled gas flow rate based on output signals from one or more sensors 18. In some embodiments, the CO2 monitoring component 32 is configured to determine the inspiratory flow rate, expiratory flow rate, and / or other gas flow rates within the interface device. In some embodiments, the overall expiratory flow rate is determined. In some embodiments, the CO2 monitoring component 32 is configured to determine the flow rate of a portion of the exhaled gas and to determine one or more respiratory gas parameters based on output signals from the sensors 18.

[0039] The correction factor determination component 36 is configured to receive VO2 and VCO2 information from the metabolic monitoring component 30, and VCO2 information from the CO2 monitoring component 32. In some embodiments, the correction factor determination component 36 is configured to determine a correction factor based on the VCO2 information received from the metabolic monitoring component 30 and the VCO2 information received from the CO2 monitoring component 32. Measurements from the CO2 monitor are used to improve the accuracy of metabolic monitoring measurements of VCO2 and VO2. In some embodiments, a correction factor is applied to VO2 measurements from the metabolic monitor. This correction can improve the accuracy of vital signs needed to understand a patient's metabolic needs.

[0040] In some embodiments, the correction factor can be calculated as the quotient of VCO2 from the CO2 monitor and VCO2 from the metabolic monitor. The correction component 38 is configured to receive the determined correction factor from the correction factor determination component 36. In some embodiments, the correction component 38 is configured to determine the corrected VO2 of O2 consumed by the subject based on the correction factor. In some embodiments, the corrected VO2 is the product of the VO2 from the metabolic monitor and the correction factor. The corrected VO2 represents the volume of O2 exhaled by the patient per minute when the gas analyzed by the metabolic monitor is sampled in the expiratory limb. To calculate the patient's consumed O2, the corrected measurement from the metabolic monitor is subtracted from the O2 supplied to the patient (e.g., via a ventilator).

[0041] Figure 2 An example 200 of a model for determining a correction factor is illustrated. In some embodiments, model 200 may be executed by one or more components of system 10. In some embodiments, model 200 may be executed by one or more components of processor (20). From a CO2 monitor (similar to...) Figure 1 The VCO2 measurement 212 from the CO2 monitor 17 is input into the model 216. The data from the metabolic monitor (similar to...) Figure 1VO2 and VCO2 measurements 214 from the metabolic monitor 16 are input into model 216. Model 216 is configured to receive VCO2 measurements from both monitors that will be used to calculate a correction factor. The correction factor is applied to the VO2 measurement from the metabolic monitor. The correction factor can be calculated as the quotient of VCO2 from the CO2 monitor and VCO2 from the metabolic monitor. The VO2 of O2 consumed by the subject is corrected based on the correction factor. In some embodiments, the corrected VO2 is the product of the VO2 from the metabolic monitor and the correction factor.

[0042] In some embodiments, a model is used to calculate a correction factor based on simulations of mechanically ventilated patients. In this model, different values ​​for O2 consumption and CO2 production can be simulated. Specifically, the simulated patient produces 300 ml / min of CO2 and consumes 300 ml / min of O2. Figure 3 Example 300 illustrates curves showing the changes in VCO2 over time as determined using a simulation model and a CO2 monitor. Yellow represents measurements 310 generated by the patient using the simulation model. Green represents measurements 312 from a CO2 monitor (e.g., a carbon dioxide recorder). As can be seen from example 300, the two measurements are close. Figure 4 Example 400 illustrates curves representing VCO2 measurements using an ideal proportional sampling protocol and a metabolic monitoring device, and VCO2 measurements from the same metabolic monitoring device but with a sampling protocol varying over time. Blue represents VCO2 measurements 414 from the metabolic monitor using the ideal proportional sampling protocol. Red represents VCO2 measurements 416 from the same metabolic monitor where sampling varies from 1.5% to 5% over time (based on the amplitude of the subject flow). It can be observed that these two measurements differ by approximately 10%. This difference determines the correction factor used to correct for the VCO2 measurements from the metabolic monitor.

[0043] exist Figure 5 The diagram shows an example 500 of a graph representing VO2 measurements. Green represents VO2 measurements 515 from a metabolic monitor using an ideally proportioned sampling protocol. Light blue represents VO2 measurements 517 from a metabolic monitor using a more realistic sampling protocol. Dark red represents VO2 measurements 519 from one or more actual metabolic monitors adjusted using a correction factor. Figure 5 It can be seen that measurements from metabolic monitors using more realistic scale sampling have an inaccuracy of approximately 10%. However, using a correction factor calculated using VCO2 from a CO2 monitor and VCO2 from the same metabolic monitor reduces the inaccuracy to 0.3%.

[0044] Return to Figure 1 System 10 may include one or more of external resources 14, electronic storage devices 22, client computing platforms (multiple) 24, a network 26 and / or other components, all of which are communicatively coupled via the network 26.

[0045] External resource 14 includes sources of patient and / or other information. In some embodiments, external resource 14 includes sources of patient and / or other information, such as databases, websites, external entities involved in system 10 (e.g., a healthcare provider's medical record system storing medical history information of a patient population), one or more servers outside system 10, networks (e.g., the Internet), electronic storage devices, devices associated with Wi-Fi technology, devices associated with Bluetooth® technology, data input devices, sensors, scanners, and / or other resources. In some embodiments, some or all of the functions attributable herein to external resource 14 may be provided by resources included in system 10. External resource 14 may be configured to communicate with processor 20, computing device 24, electronic storage device 22, and / or other components of system 10 via wired and / or wireless connections, via networks (e.g., local area networks and / or the Internet), via cellular technology, via Wi-Fi technology, and / or via other resources.

[0046] Electronic storage device 22 includes an electronic storage medium for electronically storing information. The electronic storage medium of electronic storage device 22 may include one or both of a system storage device that is integrally provided with system 10 (i.e., substantially non-removable) and / or a removable storage device that is removably connected to system 10 via, for example, a port (e.g., a USB port, a FireWire port, etc.) or a drive device (e.g., a disk drive, etc.). Electronic storage device 22 may be ( wholly or partially) a separate component within system 10, or electronic storage device 22 may be (wholly or partially) integrally provided with one or more other components of system 10 (e.g., computing device 18, processor 20, etc.). In some embodiments, electronic storage device 22 may be located in a server along with processor 20, in a server as part of external resource 14, in computing device 24, and / or in other locations. Electronic storage device 22 may include one or more optically readable storage media (e.g., optical discs, etc.), magnetically readable storage media (e.g., magnetic tape, magnetic hard disk drives, floppy disk drives, etc.), charge-based storage media (e.g., EPROM, RAM, etc.), solid-state storage media (e.g., flash memory drives, etc.), and / or other electrically readable storage media. Electronic storage device 22 may store software algorithms, information determined by processor 20, information received via computing device 24 and / or graphical user interface 40 and / or other external computing systems, information received from external resources 14, sensors 18, and / or other information enabling system 10 to operate as described herein.

[0047] Multiple client computing platforms 24 are configured to provide an interface between subject 12, caregivers (e.g., doctors, nurses, friends, family members, etc.), patients, and / or other users and system 10, through which subject 12 and / or other users can provide and receive information from system 10. For example, multiple client computing platforms 24 can display to users output representations (e.g., graphs, 2D / 3D images, video, audio, text, etc.) from metabolism monitor 16, CO2 monitor 17, sensor 18, and processor 20. This enables data, prompts, results, instructions, and / or any other communicable items (collectively, “information”) to communicate between users (e.g., subject 12, doctors, caregivers, and / or other users) and one or more of the metabolism monitor 16, CO2 monitor 17, sensor 18, processor 20, electronic storage device 22, and / or other components of system 10.

[0048] In some embodiments, the computing device 24 may be included in the metabolic monitor 16, CO2 monitor 17, sensor 18, processor 20, or other components of the system 10. In some embodiments, the personal computing device 24 may be included in a desktop computer, laptop computer, tablet computer, smartphone, wearable device, medical device, and / or other computing device associated with the subject 12, individual caregiver, patient, and / or other user. In some embodiments, the personal computing device 24 may be included in equipment used in a hospital, a doctor's office, and / or other medical facilities for patients; testing equipment; equipment for treating patients; data input devices; and / or other devices.

[0049] In some embodiments, computing device 24 is configured to provide information to and / or receive information from caregivers, patients, and / or other users. For example, computing device 24 is configured to present a graphical user interface 40 to facilitate the display of representations of data analysis and / or other information. In some embodiments, client computing platforms(s) 24 include multiple separate interfaces. In some embodiments, graphical user interface 40 includes multiple separate interfaces associated with computing device 24, processor 20, metabolic monitor 16, CO2 monitor 17, sensor 18, and / or other components of system 10; multiple views and / or fields configured to convey information to and / or receive information from caregivers, patients, and / or other users; and / or other interfaces.

[0050] In some embodiments, computing device 24 is configured to provide system 10 with a graphical user interface 40, processing power, a database, and / or electronic storage devices. Thus, computing device 24 may include processor 20, electronic storage device 22, external resources 14, and / or other components of system 10 (e.g., within the same housing). In some embodiments, computing device 24 is connected to a network (e.g., network 26, the Internet, etc.). In some embodiments, computing device 24 does not include processor 20, electronic storage device 22, external resources 14, and / or other components of system 10, but communicates with these components via a network. The connection to the network can be wireless or wired. For example, processor 20 may reside in a remote server, and the graphical user interface 40 may be wirelessly displayed on computing device 24 to a caregiver.

[0051] As described above, in some embodiments, the personal computing device 24 is a laptop computer, personal computer, smartphone, tablet computer, and / or other computing device. Examples of interface devices suitable for inclusion in the personal computing device 24 include touchscreens, keypads, touch-sensitive and / or physical buttons, switches, keyboards, knobs, joysticks, displays, speakers, microphones, indicator lights, audible alarms, printers, and / or other interface devices. This disclosure also contemplates that the personal computing device 24 include a removable storage interface. In this example, information can be loaded into the computing device 24 from a removable storage device (e.g., a smart card, flash drive, removable disk, etc.), enabling caregivers, patients, and / or other users to customize the implementation of the computing device 24. Other exemplary input devices and technologies suitable for use with the computing device 24 include, but are not limited to, RS-232 ports, RF links, IR links, modems (telephones, cables, etc.), and / or other devices.

[0052] Network 26 may include the Internet and / or other networks, such as local area networks, cellular networks, intranets, near-field communication, frequency (RF) links, Bluetooth. TM Wi-Fi TM And / or any of multiple types of wired or wireless networks. Such examples are not intended to be limiting, and the scope of this disclosure includes embodiments in which external resources 14, metabolic monitors 16, CO2 monitors 17, multiple sensors 18, multiple processors 20, electronic storage devices 22 and / or multiple client computing platforms 24 are operatively linked via some other communication medium.

[0053] Figure 6A method 600 for facilitating the prediction of metabolic measurements is illustrated. The system includes one or more sensors, one or more physical computer processors, and / or other components. The one or more processors are configured to execute one or more computer program components. The one or more computer program components may include a subject information component 28, a metabolic monitor component 30, a CO2 monitor component 32, a correction factor determination component 36, a correction component 38, and / or other components. The operation of method 600 given below is illustrative. In some embodiments, method 600 may be implemented using one or more additional operations not described and / or without the one or more operations discussed. Additionally, the operation of method 600 is... Figure 6 The order of the illustrations and descriptions below is not restrictive.

[0054] In some embodiments, method 600 may be implemented in one or more processing devices (e.g., digital processors, analog processors, digital circuits designed to process information, analog circuits designed to process information, state machines, and / or other mechanisms for electronically processing information). The one or more processing devices may include one or more devices that perform some or all of the operations of method 600 in response to instructions stored electronically on an electronic storage medium. The one or more processing devices may include one or more devices configured by means of hardware, firmware, and / or software to specifically design for performing one or more operations of method 600.

[0055] At operation 602, initial concentration measurements of O2 and CO2 in a portion of the subject's exhaled gas are determined. In some embodiments, operation 602 is performed by the same or similar apparatus as metabolic monitor 16. Figure 1 The metabolic monitor (shown and described in this article) is executed.

[0056] At operation 604, based on the determined first CO2 concentration and the determined first O2 concentration of the exhaled gas, the subject's first O2 consumption rate VO2 and first CO2 volumetric yield VCO2 are determined. In some embodiments, operation 604 is performed in conjunction with a metabolic monitor 16 ( Figure 1 The same or similar metabolic monitors (shown and described herein) are used.

[0057] At operation 606, a second CO2 concentration in exhaled breath is measured. In some embodiments, operation 606 is controlled by a CO2 monitor 17 (in...). Figure 1 (The same or similar CO2 monitors are shown in the figure and described in this document)

[0058] At operation 608, the subject's second CO2 volumetric yield (VCO2) is determined based on the measured CO2 concentration. In some embodiments, operation 608 is performed in conjunction with a CO2 monitor 17 (in... Figure 1 (The same or similar CO2 monitors are shown in the figure and described in this document)

[0059] At operation 610, a correction factor is determined based on the determined first VCO2 and second VCO2. In some embodiments, operation 610 is performed by a correction factor determining component 36 (in... Figure 1 It is executed by the same or similar computer processor components (shown in and described herein).

[0060] At operation 612, a correction factor and a first VO2 are used to determine a corrected first VO2. In some embodiments, operation 612 is performed by a correction component 38 (in...). Figure 1 It is executed by the same or similar computer processor components (shown in and described herein).

[0061] In the claims, any reference numerals placed in parentheses should not be construed as limiting the claims. The word "comprising / including" does not exclude the presence of elements or steps other than those listed in the claims. In a device claim listing several means, several of these means may be implemented by the same hardware. The words "a" or "an" preceding an element do not exclude the presence of a plurality of such elements. In any device claim listing several means, several of these means may be implemented by the same hardware. The fact that certain elements are recited in mutually different dependent claims does not mean that these elements cannot be used in combination.

[0062] While the description provided above is based on embodiments currently considered to be most practical and preferred, and provides for illustrative purposes, it should be understood that such details are for that purpose only, and that this disclosure is not limited to the explicitly disclosed embodiments, but rather is intended to cover modifications and equivalent arrangements falling within the spirit and scope of the appended claims. For example, it should be understood that this disclosure contemplates that one or more features of any embodiment may be combined with one or more features of any other embodiment to the extent possible.

Claims

1. A system (10) for metabolic measurement, the system comprising: The metabolic monitor (16) is configured as follows: Determine the first concentration measurements of O2 and CO2 in a portion of the exhaled air exhaled by the subject during one or more breaths; as well as Based on the determined first O2 concentration in the portion of the exhaled gas and the determined first CO2 concentration in the portion of the exhaled gas, the subject's first O2 consumption rate VO2 and first CO2 volume production VCO2 during one or more breaths are determined. The CO2 monitor is configured as follows: Determine the second CO2 concentration measurement in the exhaled gas of the subject during one or more breaths; and Based on the measured second CO2 concentration, determine the second CO2 volumetric yield (VCO2) of the subject during one or more breaths; as well as One or more physical computer processors (20) operatively connected to the metabolic monitor and the CO2 monitor, the one or more physical computer processors being configured by computer-readable instructions to: Based on the determined first VCO2 and second VCO2, a correction factor is determined; and The corrected first VO2 is determined using the correction factor and the first VO2.

2. The system of claim 1, wherein the correction factor is determined as the quotient of the second VCO2 from the CO2 monitor and the first VCO2 from the metabolic monitor.

3. The system of claim 1, wherein the corrected first VO2 is the product of the correction factor and the first VO2.

4. The system of claim 1, wherein the CO2 monitor is a carbon dioxide profiler.

5. The system of claim 1, wherein the one or more physical computer processors are configured to determine a corrected first VCO2 using the correction factor and the determined first VCO2.

6. The system of claim 5, wherein the one or more physical computer processors are configured to determine the metabolic state of the subject based on the corrected first VO2 and the corrected first VCO2.

7. The system of claim 5, wherein the one or more physical computer processors are configured to measure energy expenditure (EE) and / or respiratory quotient (RQ) based on the calibrated first VO2 and the calibrated first VCO2.

8. The system according to claim 1, wherein: The metabolic monitor includes multiple sensors (15) configured to output signals relating to one or more respiratory parameters of the subject during one or more breaths; and The one or more physical processors are further configured to: determine, based on the one or more respiratory parameters of the subject, the first concentration measurements of O2 and CO2 in the portion of the exhaled gas exhaled by the subject.

9. The system of claim 8, wherein the one or more sensors (15) include a flow rate sensor (21) configured to measure the flow rate of said portion of the exhaled gas during said one or more breaths.

10. The system according to claim 1, wherein: The CO2 monitor includes multiple sensors (25) configured to output signals relating to one or more respiratory parameters of the subject during one or more breaths; and The one or more physical processors are also configured to determine a second CO2 concentration measurement in the exhaled gas exhaled by the subject based on the one or more respiratory parameters of the subject.

11. The system of claim 10, wherein the one or more sensors (25) include a flow sensor (29) configured to measure the flow rate of the exhaled gas during one or more breaths.

12. The system according to claim 1, wherein the metabolic monitor comprises one or more of an O2 sensor (13) and / or a CO2 sensor (11).

13. The system of claim 1, wherein the CO2 monitor comprises one or more of a CO2 sensor (27) and / or a flow rate sensor (29).

14. A method for metabolic measurement, the method comprising: Using a metabolic monitor (16), first concentration measurements of O2 and CO2 in a portion of the exhaled air exhaled by the subject during one or more breaths were determined; Using the metabolic monitor, based on the determined first O2 concentration in the portion of the exhaled gas and the determined first CO2 concentration in the portion of the exhaled gas, the subject determines the first O2 consumption rate VO2 and the first CO2 volume production VCO2 during one or more breaths. Using a CO2 monitor (17), a second CO2 concentration measurement was determined in the exhaled gas exhaled by the subject during one or more breaths; Using the CO2 monitor, the second CO2 volumetric output (VCO2) of the subject during one or more breaths is determined based on the measured second CO2 concentration; Using one or more physical computer processors (20), a correction factor is determined based on the determined first VCO2 and second VCO2; as well as Using one or more physical computer processors (20), the correction factor and the first VO2 are used to determine the corrected first VO2.

15. The method of claim 14, wherein the correction factor is determined as the quotient of the second VCO2 from the CO2 monitor and the first VCO2 from the metabolic monitor.

16. The method of claim 14, wherein the corrected first VO2 is the product of the correction factor and the first VO2.

17. The method of claim 14, wherein the CO2 monitor is a carbon dioxide recorder configured to continuously measure the concentration of CO2 in exhaled gas.

18. The method of claim 14, further comprising: Using one or more physical computer processors, the correction factor and the determined first VCO2 are used to determine the corrected first VCO2.

19. The method of claim 18, further comprising: The subject's metabolic state is determined using one or more physical computer processors based on the corrected first VO2 and the corrected first VCO2.

20. The method of claim 18, further comprising: Energy expenditure (EE) and / or respiratory quotient (RQ) are determined using one or more physical computer processors based on the corrected first VO2 and the corrected first VCO2.

21. The method of claim 14, further comprising: Using multiple sensors (15) in the metabolic monitor, output signals related to one or more respiratory parameters of the subject during one or more breaths are provided; as well as Using one or more processors, based on the output signal from the sensor, the first concentration measurement of O2 and CO2 in the portion of the subject's exhaled gas is determined.

22. The method of claim 21, wherein the one or more sensors (15) include a flow rate sensor configured to measure the flow rate of the portion of the exhaled gas during the one or more breaths.

23. The method of claim 14, further comprising: Using multiple sensors (25) in the CO2 monitor, output signals related to one or more respiratory parameters of the subject during one or more breaths are provided; as well as Using one or more processors, the second CO2 concentration measurement in the subject's exhaled gas is determined based on the output signal from the sensor.

24. A system for metabolic measurement, the system comprising: Device for determining a first concentration measurement of O2 and CO2 in a portion of the exhaled air exhaled by a subject during one or more breaths; A device for determining, based on a determined first O2 concentration in a portion of the exhaled gas and a determined first CO2 concentration in a portion of the exhaled gas, the subject's first O2 consumption rate VO2 and first CO2 volumetric yield VCO2 during one or more breaths. Device for determining a second CO2 concentration measurement in the exhaled gas exhaled by the subject during one or more breaths; Device for determining the second CO2 volumetric output (VCO2) of the subject during one or more breaths based on the measured second CO2 concentration; A means for determining a correction factor based on the determined first VCO2 and second VCO2; as well as A means for determining the corrected first VO2 using the correction factor and the first VO2.

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