Patent Description:
Methods and devices for measuring quantitative airway carbon dioxide (CO<NUM>) gas exchange concentrations and respiratory rate of a subject's breath (capnometry) are well known in the clinical markets. In fact, the use of capnometry during intubated surgical and otherwise critical ventilated patient situations is mandated by standards organizations because it is critical in maintaining safety. By far the most common technology used in commercial instruments is IR spectroscopy because of its accuracy, precision, speed of response and reliability. Infrared absorption spectroscopy capnometers quantify the subject's airway CO<NUM> gas exchange in real time without any airway perturbation or violation of sterility. Unfortunately, this utility requires substantial technological complexity and a high price when compared with other common medical parameter measurements such as temperature, blood pressure, ECG, heart rate and pulse oximetry. Now that the use of capnometry has expanded outside the in-hospital environment to pre-hospital emergency care including non-intubated subject monitoring applications such as dentistry, pain management, conscious sedation, in-home use, etc., there is an increased awareness of the need for less expensive capnometry instruments.

There are many other techniques for measuring gas exchange in a subject's breath. Among these include mass spectrometry, Raman scattering, photoacoustic, piezoelectric, paramagnetic and chemical based instruments. All of these techniques have specific tradeoffs with respect to their complexity, performance and cost. In examining the aspects of these tradeoffs, one technique stands alone as having potential for simplicity, meeting adequate performance criteria at considerably lower cost than other methods; the chemical based colorimetric technique.

Chemical based colorimetric techniques have been utilized in many other applications including qualitative human breath CO<NUM> measurement. However, one of the challenges in using colorimetric techniques is its ability to achieve sufficient response time to capture rapidly changing CO<NUM> concentrations such as is found in a subject's ventilation pattern. Commercially available airway colorimetric products first appeared in the late <NUM>'s, but could only give relative qualitative indications of CO<NUM> concentrations due to their slow response. In the <NUM>'s, improvements to the indicator chemistry formulations were made to enhance the speed of response to breath-by-breath gas concentration variations. For example, in <NUM> Dr. Andras Gedeon published test results of a colorimetric indicator compared with an IR spectroscopy based capnometer showing significant similar breath-by-breath response. Details regarding these test results are described in the paper "<NPL>. Since then, Dr. Gedeon and others have also developed and manufactured qualitative colorimetric indicators primarily for use with intubation verification.

Although much has been done to improve chemical based colorimetric techniques, there remains a need for a low cost quantitative CO<NUM> device that provides fast and accurate continuous measurement of a subject's breath-by-breath CO<NUM> levels. Moreover, there is a need for a portable device that can be used by patients at home or otherwise to monitor CO<NUM> levels as part of a treatment protocol. As such, the embodiments described herein provide devices, systems, and methods for addressing at least these concerns. For example, some embodiments provide for electro-optical techniques instead of visual interpretation to detect the color change from CO<NUM> concentrations. Other embodiments provide for devices or systems that display continuous calibrated CO<NUM> concentrations and respiratory rates using colorimetric indicator chemistry. Additionally, methods and devices contemplated herein include new techniques for user calibration and unique patient attachments or patient interface for various clinical applications to allow quantitative monitoring of a spontaneously breathing (non-intubated) subject with a completely robust, portable, very low cost, low power instrument. The simplicity of this instrument is suited, at least, for the technology-unsophisticated, home-based user.

In addition, some embodiments described provide examples of breathing therapy for treating any number of disorders including panic disorder, hypertension, post-traumatic stress disorder (PTSD), asthma etc. Although breathing therapies or methods (e.g. yoga and meditation) have been used in the past as ways to reduce anxiety or hyperventilation, such breathing techniques are focused primarily on relaxing or calming the practitioner and not on modifying carbon dioxide levels during respiration for treatment. In particular, previous techniques have not used a quantitative colorimetric carbon dioxide system for therapy. As such, the quantitative colorimetric devices and systems described herein can be used to provide breathing therapy treatment by, for example, helping patients modify end-tidal CO<NUM> levels to help treat panic disorder, PTSD, anxiety, general anxiety disorder, obsessive-compulsive disorder, social phobia, depression, apnea, migraines, epilepsy, asthma, hypertension, conscious sedation, emergency medical services (EMS), etc..

<CIT>, discloses an apparatus for inducing a pediatric patient to inhale a fluid pharmacological agent through a face mask. The apparatus comprises a fluid conduit through which fluid pharmacological agent may be inhaled, and a visual patient stimulator coupled to said conduit and actuatable by inspiratory or expiratory flow through said conduit. The visual stimulator of the present invention changes color in response to changing gas levels which occur during inspiration and expiration.

<NPL> [I] <NUM>-<NUM>,<NUM>-<NUM> discloses that raising end-tidal pC02 by means of capnometry-assisted feedback is therapeutically beneficial for panic patients. Capnometry feedback is said to be a direct and convincing way to correct problematic breathing patterns associated with hyperventilation, ensuring that the primary goal of breathing therapy is being attained.

<CIT> discloses a detection sensor assembly comprising; an indicator sensor; a flow housing comprising two fluidic ports; an indicator target comprising at least one indicator moiety; and an indicator window. The indicator sensor is responsive to at least one indicator moiety influenced by changing fluidic environments presented to the indicator target. The indicator moiety may be a chemistry which induces a colorimetric response.

Any "aspect", "example" and "embodiment" of the description not falling within the scope of the claims does not form part of the invention and is provided for illustrative purposes only.

The present disclosure relates to quantitative colorimetric systems and methods for using the same. The quantitative colorimetric systems can be used to provide a user with a breathing therapy.

The invention are set forth in the claims that follow.

Quantitative colorimetric carbon dioxide detection and measurement systems are disclosed herein. The systems can include a gas conduit configured to provide a carbon dioxide gas sample to a colorimetric indicator. The colorimetric indicator is adapted to exhibit a color change in response to exposure to carbon dioxide gas. An electro-optical sensor assembly including a light source or sources can transmit light to the colorimetric indicator. A photodiode or photodiodes can detect light reflected from the colorimetric indicator and generate a measurement signal corresponding to the color change of the colorimetric indicator in response to the exposure to carbon dioxide gas. A processor in communication with the electro-optical sensor assembly can receive the measurement signal generated by the electro-optical sensor assembly and compute a concentration of carbon dioxide based on the measurement signal. Methods for using the systems are also disclosed including providing a breathing therapy to a patient or user.

Reference will now be made in detail to exemplary embodiments of the disclosure, examples of which are illustrated in the accompanying drawings.

Various embodiments disclosed herein are directed to devices and systems that provide quantitative colorimetric CO<NUM> measurement from a breath sample. <FIG> shows an example of a quantitative colorimetric CO<NUM> detection system. The detection system <NUM> includes an inlet/conduit <NUM> directing a breath sample or a gas to enter the detection system. In some embodiments, the inlet/conduit <NUM> may be coupled to or can include a gas or fluid conduit to allow gas to pass from the inlet/conduit <NUM> to a colorimetric indicator <NUM>. In some embodiments, the inlet/conduit <NUM> may connect to or be in fluid communication with a sensing chamber having sensing elements, such as a colorimetric indicator and electro-optical assembly.

Once a gas sample, which may be a portion of a patient's exhaled breath or the complete exhaled breath, reaches the colorimetric indicator <NUM>, the colorimetric indicator <NUM> changes color based on the volume percent concentration of CO<NUM> exposed to the indicator <NUM>. For example, in some embodiments, the colorimetric indicator <NUM> is blue when less than <NUM>% CO<NUM> is present, blue-green when <NUM>% to <NUM>% CO<NUM> is present, green when <NUM>% to <NUM>% CO<NUM> is present and yellow when approximately <NUM>% CO<NUM> is present. The specific colors visually apparent at specific CO<NUM> concentrations levels within the range of approximately <NUM>% to <NUM>% can be adjusted with different chemistry formulations.

With quantitative CO<NUM> colorimetric measurements, once the color shift is determined, it can be desirable that the specific color shift at specific CO<NUM> concentrations is repeatable. This may involve manufacturing quality assurance processes to validate this characteristic within various batches of colorimetric material.

In some embodiments, the concentration of carbon dioxide detected by the indicator is used to determine or derive a partial pressure for the carbon dioxide in the gas or breath sample. For example, if a total pressure of a breath sample is known (or measured) and the percentage of carbon dioxide present in that breath sample is measured, then the partial pressure of the carbon dioxide in the sample can be calculated or derived. Additionally, in some cases, calculations are performed to determine a mean, median, or mode gas component value. In some cases, the carbon dioxide values measured in multiple breaths (e.g. more than one exhalation or inhalation) are averaged to determine a computed average carbon dioxide value.

In further embodiments, the indicator is adapted to change color based on the partial pressure of carbon dioxide present. In some cases, the indicator is adapted to change color according to partial pressures of about <NUM> mmHg (first color); <NUM>. 2mmHg (second color); <NUM> mmHg (third color); <NUM> mmHg (fourth color); and <NUM> mmHg (fifth color) of a gas component such as carbon dioxide.

Several different chemical formulations for colorimetric indicators can be used in the contemplated embodiments. Some embodiments include a chemical colorimetric indicator having a substrate with a reagent that is reactive to CO<NUM>. Once the substrate is exposed to the CO<NUM>, the reagent reacts to create a color change in the substrate. In some embodiments, the indicator is a thin film or membrane with a CO<NUM> sensitive reagent. In some embodiments, for quantitative measurements, the color shift in the presence of CO<NUM> is indicated on both sides of the film.

Referring again to <FIG>, the colorimetric indicator may be coupled to an electro-optical sensor assembly <NUM>. The electro-optical sensor assembly may be configured to detect the color change in the colorimetric indicator. For example, the assembly <NUM> may include a light source/emitter such as a mono, bi or tri-color LED assembly that is combined and pulsed to emit certain wavelengths of light ranging from near infrared to ultraviolet that in turn are transmitted to a surface of the colorimetric indicator. Some of the light that encounters the surface of the indicator will be reflected, scattered, or absorbed by the indicator. Light reflected back from the indicator may be synchronously detected by a photodetector such as one or more photodiodes that generates an electrical signal based on the detected reflected light.

In some embodiments, an indicator color change is detected by determining the intensity and wavelength shift in the light reflected from the indicator. In some cases, a reference light source having one or more reference wavelengths is alternately transmitted to the indicator surface. For example, a light of a first wavelength may be alternated with a light of a second wavelength for transmission to the indicator. The reference wavelength(s) may be selected so as to not be sensitive to the CO<NUM> induced wavelength shift but are sensitive to other factors such as surface contamination, ambient light, optics misalignment, temperature effects and colorimetric indicator aging. A microprocessor can be employed to compare the reference reflected light output with the reflected light output from the CO<NUM> induced signal to compensate for artifact and provide other user error messages. In some cases, the reference wavelength that is not sensitive to the indicator color shift is used to determine measuring conditions (including compensation factors).

Additionally, calibration methods may incorporate a ratiometric, dual wavelength electro-optical measurement system which rejects common mode interferences such as: misalignment of indicator/sensor combination, electro-optical component drift, ambient temperature effects, ambient light effects, indicator contamination (mucus, moisture, dust, air pollution compounds), presence of anesthetic agents or nebulized medications, indicator aging phenomena; batch to batch chemistry variability, etc. Ratiometric measurements that may be suitable include those commonly used with other optically based sensor systems such as IR spectroscopy based capnometers and pulse oximeters.

As described, the electro-optical assembly <NUM>, shown in <FIG>, may include one or more light emitter(s), one or more photodetector(s), and other suitable components such as a lens, diffuser or collimator. In some embodiments, the photodetector receives the reflected light from the indicator and generates an electrical signal. The electrical signal may be transmitted to a microcontroller or a processor. Depending on the reflected light received by the photodetector, the photodetector may generate one or more electrical signals based on the received reflected light. For example, if a first electric signal may be generated for a first detected reflected light and a second electric signal may be generated for a second detected reflected light. The first and second signals may be used for comparison or computation to measure the tested gas component in the sample. In some embodiments one or more photodetectors can be used with the one or more light emitters. For example, two light emitters could be used with two corresponding photodetectors.

The operating electronics <NUM> may include a processor configured to receive the electrical signal(s) from the photodetector(s). The processor may be further configured to process the electrical signal and compute the amount of CO<NUM> in the gas sample. The amount of CO<NUM> may be computed in any suitable units including concentration percentage in the breath sample or CO<NUM> partial pressure (mmHg). In some variations, the pressure of the CO<NUM> can be derived from other measured values such as concentration percentage. In Some embodiments the processor is within the housing of the device. In some embodiments the processor is in communication with the system and receives the electrical signal. In some embodiments the processor is external to the quantitative detector.

Additionally, in some embodiments, the processor includes calibration data for the system, which is used to determine the quantity of CO<NUM> based on the color shift detected by the electro-optical assembly <NUM>. In some embodiments a calibration can be applied to the color shift detected by the electro-optical assembly based on a temperature of the colorimetric film or breath sample. The temperature correction or calibration can be a look-up table or formula tailored to the specific colorimetric material. In some embodiments the temperature correction or calibration is applied to the measurement signal by the processor.

In further embodiments, the detection system <NUM> may include a display or monitor <NUM>. The display <NUM> may include a user interface for user information input. In other variations, the display <NUM> may display the computed CO<NUM> measurements. The CO<NUM> measurement values may be in any suitable units including pressure units of Torr or mmHg. The display <NUM> outputs visual or audio cues guiding the user through a breathing maneuver to modify CO<NUM> levels. In other embodiments the display <NUM> may be wirelessly connected to the internet including cloud based computational methods. In some embodiments, the display is not a separate component and is instead integrated with the operating electronics <NUM>. For example, the operating electronics and display may be a mobile device such as a smart phone, tablet, or other computing device programed to interface with and operate one or more of the electro-optical sensor assembly, colorimetric indicator, and inlet. In some embodiments the display is a non-mobile device. For example, the display could be a television or monitor that receives the image data to display. In some embodiments the processor could be attached to or in communication with the television, for example as a gaming system, media streaming device, antenna, or other device configured to provide image data to an input on a display.

<FIG> shows additional details regarding another embodiment of a quantitative colorimetric CO<NUM> detection system <NUM>. The system <NUM> includes a gas permeable shield or protective shield <NUM> around a colorimetric chemical indicator <NUM>. In some cases, the shield protects the indicator from physical contamination, such as touching by a user, while allowing fluid (e.g. gas) movement through the shield to the indicator. In some embodiments, an annular ring surrounds and shields the indicator from unwanted contaminating contact. For example, the annular ring may include a cavity in which the indicator sits. The ring may be porous or otherwise gas permeable to allow gas movement to the indicator through the ring.

In some variations, the colorimetric indicator is a thin film or membrane having a reagent that is reactive to CO<NUM>. Upon exposure to CO<NUM>, the reagent reacts to create a color change. In other embodiments, the color change is indicated on both sides of the thin film or membrane. Advantageously, in some variations, the color change is optically or visually detectable. In some cases, the colorimetric indicator/sensor can be made very small/lightweight (< <NUM>" diameter) and thus can be placed directly in the exhaled breath flow path. In some embodiments, there is no gas entrainment (vacuum pump) required. As such, colorimetric CO<NUM> sensing can combine the advantages of both sidestream capnometers (easily attached to non-intubated subject) and mainstream capnometers (no time delay, no pump, no sample line plugging). The entire sensor assembly could also be disinfected.

As shown in <FIG>, the colorimetric indicator <NUM> can be positioned on a transparent window <NUM>. In some embodiments, the indicator <NUM> is affixed or adhered to the window <NUM>. The transparent window <NUM> allows the transmission of light to a surface of the indicator. The transparency also allows reflectance of the light from the indicator to an electro-optical assembly <NUM> coupled to the colorimetric indicator. In other embodiments, the window <NUM> may be a plate or substrate that is substantially optically clear such that visible light can transmit (and reflect) therethrough.

In some embodiments, the colorimetric chemistry indicator is contained within a clear sealed plastic gas filled cell while allowing the sensor to record the color. After this "span" calibration to a known gas concentration is recorded in the processor, the operator is then prompted to peel off the plastic gas filled cell exposing the indicator to the environment (e.g. ambient air) and at that time the processor will perform a "zero" calibration point before attaching the indicator/sensor to the subject. Alternate calibration techniques may employ inserting a known color sample unaffected by the presence of CO<NUM> while still reflecting light back to the sensor. As described, in other embodiments, calibration methods may incorporate a ratiometric, dual wavelength electro-optical measurement system which rejects common mode interferences.

The electro-optical assembly <NUM> may include one or more pulsed light emitters or sources such as an LED. Each light emitter transmits a known wavelength of light to a surface of the indicator <NUM> through the transparent window. Varying amounts of light will reflect from the indicator <NUM>, which is undergoing color shift from exposure to CO<NUM>, back toward the electro-optical assembly <NUM>. A photodetector such as a photodiode detects the amount of reflected light resulting from the color shift and generates a CO<NUM> concentration signal that is transmitted to an electronics module <NUM>. In some cases, a cable <NUM> couples the electro-optical assembly <NUM> to the electronics module <NUM>.

The electronics module <NUM> may include a power supply (e.g. battery) for the system <NUM>. Advantageously, embodiments contemplated will require low power for operation. Many hours of operation are contemplated with the use of hearing aid batteries. In other embodiments rechargeable Lithium ion batteries may be employed as a power source.

In other variations, the electronics module <NUM> has a microcontroller or processor configured to operate the system. In further variations, the processor/microcontroller receives the signal(s) generated by the electro-optical assembly and computes a CO<NUM> measurement for the gas sample based on the signal. As part of the CO<NUM> computation, the processor/microcontroller may include calibration data and the methods for the system described herein. The processor can calculate additional characteristics of the gas sample, such as the respiration rate of the user or patient. The calibration data may include a calibration curve specific to the particular colorimetric chemical formulation. The calibration data can also include temperature correction data for the particular colorimetric chemical formulation. The calibration data may be stored in flash memory or in the processor.

In further variations, the system <NUM> may include an indicator housing that holds the protective shield <NUM>, indicator <NUM>, and transparent window <NUM>. The indicator housing may be disposable, replaceable, or otherwise removable from the system <NUM>. The separate sensor housing may also contain the electro-optical assembly and, optionally, the sensor cable. The sensor housing may be releasably coupled to the indicator housing holding the shield, indicator, and transparent window. This allows removal and replacement of the indicator once indicator use has been exhausted. For example, a chemical colorimetric indicator may last <NUM> hours of use and require replacement for continued operation of the detection system.

In further embodiments, an indicator unit that includes the indicator, a protective shield, and an optically transparent substrate may be integrated with a user interface to detect a breath sample from the nose or mouth. For example, the indicator unit may be formed as a nasal or oral interface that is easily attached near, on, or adjacent to an airway or airflow. The indicator unit may be clipped, for example, to the nose to monitor and measure a patient's CO<NUM> levels. In some embodiments, a disposable indicator unit can be attached and detached from a reusable electro-optical sensor assembly. This could include a tiny magnetic latching mechanism or any other suitable attachment means. Other means of attachment/detachment could employ a plastic molded snap on-off mechanism or a quarter- turn latch mechanism.

<FIG> shows a display module <NUM> may be either hardwired or wirelessly connected to the electronics module <NUM>. The display module may include a computer such as a mobile device or a handheld device that is capable of displaying instructions, CO<NUM> measurements, or a breathing protocol. In further embodiments, the electronics module <NUM> and display module <NUM> are a single unit or device. The entire system <NUM> may be portable and/or handheld.

<FIG> and <FIG> illustrate embodiments of flow charts <NUM>, <NUM> for process flows. As shown in <FIG> a carbon dioxide sample <NUM>, <NUM> enters a gas or fluid conduit <NUM>, <NUM> and contacts the colorimetric indicator <NUM>, <NUM>. A pump <NUM>, <NUM> can be used to pump the carbon dioxide into contact with the colorimetric indicator. The pump can be downstream of the colorimetric indicator (<FIG>) or upstream of the colorimetric indicator (<FIG>). The carbon dioxide can exit <NUM>, <NUM> the system after contacting the colorimetric indicator <NUM>, <NUM>. The electro-optical sensor assembly <NUM>, <NUM> interrogates the colorimetric indicator <NUM>, <NUM> when the carbon dioxide stream contracts the colorimetric indicator <NUM>, <NUM>. The electro-optical sensor assembly <NUM>, <NUM> outputs a measurement signal <NUM>, <NUM> based on the interrogation of the colorimetric indicator <NUM>, <NUM>. The measurement signal <NUM>, <NUM> can be sent to an onboard processor <NUM>, <NUM> that analyzes the measurement signal <NUM>, <NUM> to determine the amount of carbon dioxide contacting the colorimetric indicator <NUM>, <NUM>. As an alternative option the measurement signal <NUM>, <NUM> can be transmitted to an external processor <NUM>, <NUM> with the external processor determining the amount of carbon dioxide that contacts the colorimetric indicator <NUM>, <NUM>. Data associated with the interrogation of the colorimetric indicator can then be displayed <NUM>, <NUM>, <NUM>, <NUM>. The display can be onboard the device (<NUM>, <NUM>), external to the device (<NUM>, <NUM>), part of a tablet, smartphone, or computer in communication with the device.

<FIG> illustrates an example of a patient using a quantitative colorimetric carbon dioxide measuring system <NUM> in some embodiments. Exhaled breath of the patient enters an inlet <NUM>, illustrated as a nasal cannula, and flows through a conduit or cannula <NUM> and into the quantitative colorimetric carbon dioxide measuring system <NUM>.

<FIG> illustrates a schematic of a quantitative colorimetric carbon dioxide measuring system <NUM> in accordance with some embodiments. The system <NUM> includes a conduit or inlet <NUM>. The conduit or inlet <NUM> can be configured to receive or engage with a cannula, sample inlet tube, or other conduit such that the cannula, conduit, or inlet is configured to introduce a gas sample to the system <NUM>. <FIG> illustrate various configurations of sample tube assemblies that can be connected to the system <NUM> via conduit or inlet <NUM>. In some embodiments the gas conduit includes or is configured to removably engage with a separate disposable sample inlet tube. In some embodiments the gas conduit includes or is configured to removably engage with a nasal and/or oral cannula adapted for collecting a sample of a user's exhaled breath for exhaled carbon dioxide measurement with the nasal and/or oral cannula configured to be in fluid communication with the gas conduit.

The system <NUM> includes a colorimetric indicator <NUM> within a housing <NUM> of the system <NUM>. An electro-optical sensor <NUM> can be included to interrogate the colorimetric indicator <NUM>.

A temperature controller <NUM> can be provided to control the temperature of the colorimetric indicator and/or the temperature of the incoming gas sample. The temperature controller can control a heater and a cooler to control the temperature of the colorimetric indicator and/or incoming gas sample to a pre-determined temperature. In some embodiments the pre-determined temperature is from about <NUM> to about <NUM>. In some embodiments the processor can be configured to control the temperature controller. In some embodiments the temperature controller can also be configured to control a temperature of the electro-optical sensor. In some embodiments a temperature probe can be used to measure the temperature of the colorimetric indicator, incoming gas sample, and/or electro-optical sensor.

A pump <NUM> can be included within the housing <NUM> to pump the incoming gas sample. In some embodiments the pump <NUM> can be located downstream of the colorimetric indicator to effectively pull the incoming gas sample passed the porous colorimetric indicator. In some embodiments the pump can be upstream of the colorimetric indicator to pump the gas sample passed the colorimetric indicator. In embodiments including a heater as part of the temperature controller, the pump can improve heat transfer between the colorimetric indicator and heater by increasing contact between the colorimetric indicator and heater.

The system <NUM> includes operating electronics <NUM>. The operating electronics can control the system to perform various processing steps as described herein. In some embodiments the operating electronics receive the measurement signal from the electro-optical assembly and calculate properties associated with the measurement signal. In some embodiments the operating electronics receive the measurement signal and send the measurement signal to a processor external to the system <NUM>, with the external processor performing the calculations and analysis of the measurement signal. In some embodiments the system <NUM> includes a wireless transmitter <NUM> to transmit data to an external processor, such as a processor on a computer, tablet, or smartphone.

The system <NUM> can include a power supply <NUM> to power the components of the system <NUM>.

In some embodiments the system <NUM> can include a display <NUM> with the housing <NUM>. In some embodiments the display is external to the system. For example, the display data can be wirelessly transmitted to a device having a display, such as a computer, smartphone, tablet, flat screen monitor, television, etc. In some embodiments a tablet or smartphone <NUM> can be used with the system <NUM>. The tablet <NUM> can include a processor <NUM> and display <NUM>. In some embodiments the processor <NUM> can receive the measurement signal transmitted by the system <NUM> and analyze the measurement signal to determine properties associated with the measurement signal. In some embodiments the processor <NUM> is configured to receive data from the system <NUM> and display the data on the tablet <NUM> display <NUM>. Decreasing the processing steps performed by the processor on board the system <NUM> can reduce the complexity and cost of the system <NUM>.

<FIG> illustrate configurations of sample tube assemblies in accordance with some embodiments. The sample tube assemblies illustrated in <FIG> can be used with the systems <NUM> illustrated in <FIG> and <FIG>. For example, the sample tube assemblies illustrated in <FIG> can be configured to plug in to or snap into engagement with the system <NUM>. The sample tube assemblies illustrated in <FIG> can be disposable / configured for a single use.

<FIG> illustrates a sample tube assembly <NUM> having an inlet <NUM> and tube, conduit, or cannula <NUM>. The sample tube assembly <NUM> can be engaged with a replaceable colorimetric material or cartridge <NUM>. The colorimetric material <NUM> can removably engage with the tube, conduit, or cannula <NUM>. An end <NUM> of the sample tube assembly can snap into the inlet <NUM> of the system <NUM> such that the colorimetric material <NUM> can be interrogated by the electro-optical sensor <NUM>. In some embodiments the sample tube assembly <NUM> is designed for a single use. In some embodiments the sample tube assembly <NUM> can be used multiple times with the colorimetric material <NUM> periodically replaced. When the sample tube assembly <NUM> is used with embodiments of the system <NUM>, the colorimetric material would be provided by the sample tube assembly <NUM> and would not be included within the housing <NUM> of system <NUM>.

<FIG> illustrates a sample tube assembly <NUM> with an inlet <NUM>, tube/conduit/cannula <NUM>, and a built in colorimetric material <NUM> at end <NUM>. The sample tube assembly <NUM> end <NUM> can engage with the inlet <NUM> of the system <NUM> such that the colorimetric material <NUM> can be interrogated by the electro-optical sensor <NUM>. The sample tube assembly <NUM> can be designed for single use such that the sample tube assembly <NUM> can be used until the colorimetric material <NUM> expires. When the sample tube assembly <NUM> is used with embodiments of the system <NUM>, the colorimetric material would be provided by the sample tube assembly <NUM> and would not be included within the housing <NUM> of system <NUM>.

<FIG> illustrates a sample tube assembly <NUM> with an inlet <NUM>, tube/conduit/cannula <NUM>, and built in colorimetric material <NUM> with gas chamber <NUM> at end <NUM>. The sample tube assembly <NUM> can engage with the inlet <NUM> of the system <NUM> such that the colorimetric material <NUM> can be interrogated by the electro-optical sensor <NUM>. The sample tube assembly <NUM> can be designed for single use such that the sample tube assembly <NUM> can be used until the colorimetric material <NUM> expires. When the sample tube assembly <NUM> is used with embodiments of the system <NUM>, the colorimetric material would be provided by the sample tube assembly <NUM> and would not be included within the housing <NUM> of system <NUM>.

<FIG> illustrates a sample tube assembly <NUM> with an inlet <NUM>, tube/conduit/cannula <NUM>, colorimetric material <NUM>, and electro-optical sensor <NUM> at end <NUM>. The sample tube assembly <NUM> can engage with the inlet <NUM> of the system <NUM> such that the colorimetric material <NUM> and electro-optical sensor <NUM> can communicate with the system <NUM>. The sample tube assembly <NUM> can be designed for single use such that the sample tube assembly <NUM> can be used until the colorimetric material <NUM> expires. When the sample tube assembly <NUM> is used with embodiments of the system <NUM>, the colorimetric material and electro-optical sensor would be provided by the sample tube assembly <NUM> and would not be included within the housing <NUM> of system <NUM>.

The inlets <NUM>, <NUM>, <NUM>, and <NUM> of sample tube assemblies <NUM>, <NUM>, <NUM>, and <NUM> can be connected to the user or patient by any of the structures illustrated herein or by conventional techniques. The inlets <NUM>, <NUM>, <NUM>, and <NUM> can also be coupled to accessories configured to attach to the user's nose or mouth. For example, the inlets <NUM>, <NUM>, <NUM>, and <NUM> can be configured to removably engage with and couple to a nasal and/or oral cannula adapted for collecting a sample of a user's exhaled breath for exhaled carbon dioxide measurement. In some embodiments the inlets <NUM>, <NUM>, <NUM>, and <NUM> can be configured for use with intubated patients.

The quantitative colorimetric carbon dioxide measuring system may include computer software instructions or groups of instructions that cause a computer or processor to perform an action(s) and/or to make decisions. In some variations, the system may perform functions or actions such as by functionally equivalent circuits including an analog circuit, a digital signal processor circuit, an application specific integrated circuit (ASIC), or other logic device. In some embodiments, the image recording system includes a processor or controller that performs the functions or actions as described. The processor, controller, or computer may execute software or instructions for this purpose.

"Software", as used herein, also known as firmware includes but is not limited to one or more computer readable and/or executable instructions that cause a computer or other electronic device to perform functions, actions, and/or behave in a desired manner. The instructions may be embodied in various forms such as objects, routines, algorithms, modules or programs including separate applications or code from dynamically linked libraries. Software may also be implemented in various forms such as a stand-alone program, a function call, a servlet, an applet, instructions stored in a memory, part of an operating system or other type of executable instructions. It will be appreciated by one of ordinary skill in the art that the form of software may be dependent on, for example, requirements of a desired application, the environment it runs on, and/or the desires of a designer/programmer or the like. It will also be appreciated that computer-readable and/or executable instructions can be located in one logic and/or distributed between two or more communicating, co-operating, and/or parallel processing logics and thus can be loaded and/or executed in serial, parallel, massively parallel and other manners.

There are many different methods of attaching the colorimetric CO<NUM> sensor to the patient or otherwise interfacing with the patient. Those methods may be different for different applications in the home, pre-hospital or clinical. Some of these methods are, but not limited to: over the ears similar to a nasal sampling cannula, a boom-like structure similar to a wireless headset with sensor placement near the nares; a nasal alar clip; elastic band with cup collection chamber for sensing oral/nasal exhaled air; an inline airway adapter for use with intubated patients; a non-toxic (peel and stick) adhesive sensor assembly attachment to the nares or upper lip with an ear clip cable strain relief; incorporate sensor and electronics into a pair of eyeglasses with an optional heads up display of CO<NUM> concentration and respiration rate; a headband containing the sensor/cable, electronics and power supply wirelessly connected to the remote display. Any of these attachment structures can be used with the devices disclosed herein. In some embodiments the devices described herein can be designed for use with intubated patients.

<FIG> illustrates an example of a patient using a sidestream embodiment of a quantitative colorimetric carbon dioxide measuring system <NUM> with a sample tube that is in an over-the-ear attachment mechanism. Exhaled breath of the patient enters an inlet <NUM>, illustrated as a nasal cannula, and flows through a conduit or cannula <NUM> and into the quantitative colorimetric carbon dioxide measuring system <NUM>. The inlet <NUM> can be clipped to the nose, e.g. the nasal alar cartilage.

<FIG> shows an exemplary embodiment of a quantitative colorimetric CO<NUM> detection system with a patient attachment mechanism. In some embodiments, the sensing unit <NUM> contains the colorimetric indicator and the electro-optical sensor assembly. In further variations, the sensing unit <NUM> may include a protective shield and optically clear indicator substrate as described above. The sensing unit <NUM> may be attachable to the patient by way of clips that attach to the nose, e.g. nasal alar cartilage.

In further embodiments, a small flexible insulated wire cable <NUM> leads from the sensing unit <NUM> back to an electronic module, which is located on a headband or a headphone embodiment. The colorimetric CO<NUM> sensor could be combined with a pulse oximeter sensor on the same nasal alar site, expanding use to other monitoring applications.

In further variations, an adjustable (malleable) rod or boom-like structure may be used to adjustably position the sensing unit <NUM> in the patient's nasal airflow. In some cases, a connecting cable may run through the malleable rod to connect the sensing unit to an electronic module.

As shown in <FIG>, in some cases, the patient relaxes and breathes through her/his nose to provide a breath sample for CO<NUM> measurement.

<FIG> shows another example of a patient attachment mechanism where the sensing unit <NUM> is attached to straps or cables <NUM> that connect to a handheld electronics module <NUM> that can optionally include a display.

Referring to <FIG>, a wearable quantitative colorimetric CO<NUM> detector system having a patient attachment mechanism is shown. The system <NUM> shown is capable of sampling both nasal and oral breathing patterns. The system <NUM> may be configured to alternate between sampling nasal or oral breath. Alternatively, the system may also sample only nasal or oral breath per measurement. As shown, the CO<NUM> colorimetric sensing unit <NUM> may include one or more inlets to both the nasal and oral airways. The sensing unit <NUM> may optionally operate a single inlet to allow either nasal or oral air to enter the sensing unit. In other variations, the sensing unit may include more than one inlet for capturing an air sample from either the nasal or oral airflow. In some variations, two or more separate indicator/sensor assemblies may be used to test air from each or either nasal and/or oral source. Cable <NUM> is coupled to the sensing unit <NUM> and is in electrical communication with an electronics module. In some cases, the electronics module is located remote from the patient. In other variations, the electronics module is integrated into a wearable article such as a headband.

In a further embodiment, the sensing unit <NUM> may include the indicator and the electro-optical sensor assembly. Alternatively, the sensing unit <NUM> may include the indicator and a light guide such as an optical fiber may optically couple the indicator to a remotely located electro-optical sensor assembly. For example, the colorimetric indicator chemistry may be affixed at the end of a plastic optical fiber with the electro-optics components at the other end. This could be useful in MRI imaging applications.

Various embodiments of wearable electronics modules would permit private, unrestricted, unobtrusive mobility and portability. More importantly, a wearable device would also allow the subject's hands to be unencumbered allowing other functions (eating, washing hands, holding reading material, writing, phone calling, etc.) The battery operated system could be used while the subject is ambulatory, sleeping and/or doing daily activities without being tethered to a restrictive sampling line, a bulky electronics/display module or power cord. These various embodiments would include but not limited to the electronics module: affixed or integrated into a headband, placed on back side of ear (like a hearing aid), contained within an audio headset or enclosed with lanyard worn around the neck. In all these wearable embodiments, the electronic module may employ Bluetooth wireless connectivity to remote display/storage devices (custom unit, smartphone, tablet, laptop, etc.).

<FIG> shows a headband <NUM> with a headband portion <NUM> and ends <NUM>. The headband depicted incorporates the electronics module within the headband portion and/or ends <NUM>. The headband <NUM> includes a connection port for coupling to a sensing unit as described above. A flexible sensor cable (not shown) may be used to couple the sensing unit to the headband electronics module. The sensing unit may be attachable to an airflow airway structure such as the nasal alar as suggested above.

<FIG> shows an alternate headband <NUM> configuration depicting a similar cable attachment <NUM> and a sensing unit <NUM>. The electronics module may be contained in the headband such as at the lateral caps <NUM>. In some embodiments, the wearable units described can connect through wired or wireless means to a processor or a display (e.g. smart phone) for operation of the detection systems. Instead of an ear attachment, the sensor could be clipped to the nasal alar.

<FIG> shows another wearable colorimetric carbon dioxide detection device <NUM>. The device <NUM> includes two ear pieces <NUM> and a malleable rod or boom-like structure <NUM> with a sensing unit <NUM> at the distal end. The addition of a microphone may be employed to allow the user to record audible messages. The device <NUM> may include a cable leading from the head worn attachment to a belt-worn remote electronics module.

<FIG> depicts a headphone embodiment. As shown, the electronics module and battery would be incorporated into the headphones. The headphones <NUM> would enable private audible commands, alerts, breathing instructions, (calming music), etc. thus eliminating the need for the subject to visually watch a remote digital display module. In certain applications and clinical situations, this embodiment may even eliminate the requirement for the separate remote visual display module. With the headphones securely in place, an adjustable (malleable) connecting rod <NUM>, incorporating the sensor wiring, the colorimetric sensor <NUM> and an optional microphone is positioned near the subject's nose and mouth.

In some embodiments the colorimetric film can be part of a disposable portion of the device. For example, the colorimetric indicator film can be included with or integral with a disposable inlet or sample tube assembly. <FIG> illustrate embodiments of disposable sample tube assemblies. The colorimetric indicator film can be provided as a removable and disposable module that engages with the inlet tube assembly. The colorimetric indicator film can be provided with the electro-optical module. The colorimetric indicator film can be removable relative to the electro-optical module. The colorimetric indicator film can be provided with or as part of an assembly including a protective shield designed to reduce ambient light.

For intubated spontaneous breathing patients the device can be similar to the sidestream embodiments disclosed herein. For example, the inlet could include a disposable assembly containing the colorimetric indicator film as illustrated in <FIG>. The disposable assembly can allow the operator or patient to easily and conveniently attach and remove the assembly from an electro-optical sensor assembly at some predetermined cycle to ensure system performance. The disposable assembly containing the colorimetric film can be replaced when needed.

Locating the electro-optical assembly further away from the patient's mouth can have a number of design advantages. Locating the electro-optical assembly further away from the patient's mouth/nose can make it easier to isolate the sensor from environmental effects like temperature variation and ambient light. A larger and cheaper electro-optical assembly can also be used when it is not located in close proximity to the user's mouth. In addition, locating the sensor assembly further away from the patient's mouth reduces damage and wear and tear on the electro-optical assembly. Locating the electro-optical assembly away from the patient's nose and mouth also allows for a less bulky and intrusive sample collection adjacent to the patient's nose and mouth.

A sample tube can be used to receive a portion of the gas stream sample from the subject's breath and conducting it via a small, disposable, inexpensive cannula to the electro-optical sensor. The sample tube can be connected to a remote enclosure containing the gas sensor and processing electronics. The sample tube can be connected to any of the embodiments of sample tube assemblies illustrated in <FIG>. In most cases the sampling line is a small diameter plastic assembly. The sampling line can be affixed to the patient in an "over-the-ears" fashion depicted in <FIG>, <FIG>, and <FIG>. Over-the-ears subject attachment can be used for clinical monitoring of both sedated and conscious subjects. For those few subjects who dislike or object to wearing the over-the-ears cannula, alternate patient attachments can also be used. Additionally, an exhaled gas collection cup could be employed near the end of the sample line to enhance sampling of exhaled gas simultaneously from both the subject's nose and mouth.

In another example, the colorimetric sensor can be located in close proximity to the patient's nose or mouth to receive the exhaled gas with a fiber optic cable connecting the colorimetric sensor color to the remote electro-optical assembly.

The advantages of enclosing the colorimetric indicator sensor and associated electronics inside a remote enclosure are multifold with the sampling tube embodiments. First and foremost, a "light tight" remote enclosure can prevent ambient light from interfering with the sensor. The remote enclosure can facilitate isolating the colorimetric indicator from reflected visible light interference. In addition, the somewhat fragile electro-optical components and colorimetric film can be located further away from the user's mouth, making the electro-optical sensor less likely to be subject to spills, loss, or other forms of damage or user abuse.

The sidestream configurations the colorimetric indicator can also be less susceptible to temperature variations in the ambient environment and the patient's expired air. The exhaled breath sample is aspirated through the sampling cannula, such as the sample tube assemblies illustrated in <FIG>, such that the temperature of the exhaled breath sample equilibrates to the ambient air temperature before contacting the colorimetric sensor indicator thereby reducing temperature variation effects. In some embodiments a thermal sensor or probe can be placed inside the sensor chamber to provide further temperature compensation. In another alternative a temperature controller, such as a micropower temperature controller, can be used to hold the colorimetric indicator at a constant temperature to improve system accuracy and precision as well as prevent moisture from collecting on the indicator surface. For the sidestream embodiments a pump can be used to pump the breath sample. The pump can be downstream of the colorimetric indicator or upstream of the colorimetric indicator and can improve contact between the colorimetric indicator and the temperature controller.

Additional advantages of embodiments contemplated and described herein include: (a) very low cost-complexity similar to typical portable pulse oximeter sensors and electronic readout; (b) very low power consumption-extremely portable with hearing aid style battery power; (c) simple to self-attach, unobtrusive and comfortable to wear; (d) easy user calibration (simple mechanical action while connecting disposable indicator to sensor); (e) indicator/sensor combo is non-toxic, humidity insensitive, very small, lightweight, waterproof and potentially sterilizable; (f) no sensitivity to anesthetic agents, nebulized medications, visible light, magnetic fields, RF, air particulates, acoustic noise, shock and vibration; (g) no instrument warm up time is required-simple push on button, auto power off, power on/breath detect indicator LED, error messages; (h) no aspirating pump required thus no transit time readout delay and no "sampling line" plugging; (i) home-based biofeedback CO<NUM> concentration monitoring applications - including Panic Disorder, PTSD and Asthma; (j) monitoring capability in pre-hospital emergency medical services, conscious sedation, sleep monitoring, dentistry, veterinary, supplemental O<NUM> therapy, etc.; (k) unique calibration methodology; (l) quantifiable colorimetric CO<NUM> concentration monitoring at respiratory rates up to at least <NUM> BPM ; (m) various patient attachment configurations and embodiments; (n) custom data display presentation; (o) wireless (Bluetooth) data connectivity to tablet computer or smart phone; (p) no routine maintenance of electronic module -indicator has <NUM> year shelf life; and (r) potential for revenue from disposable indicator that is replaced daily.

Additional embodiments are directed to methods for measuring a component of a patient's breath (e.g. carbon dioxide) using a quantitative colorimetric device or system such as those described herein. For example, referring generally to <FIG>, a patient may exhale into an inlet <NUM> of a quantitative colorimetric device. The inlet <NUM> directs the entire breath sample or a portion of the exhaled air into an indicator compartment, unit, or testing chamber <NUM>. The indicator unit <NUM> include a colorimetric indicator <NUM> positioned for exposure to the breath sample. Once exposed to the breath sample, the indicator changes colors from a baseline color. The color change is based on the concentration of a component (e.g. carbon dioxide) in the breath sample.

Once the breath sample has been introduced into the measurement device, an electro-optical assembly transmits a reference light to a surface of the indicator. Light reflected back from the surface of the indicator is detected by a photodetector in the electro-optical assembly. The photodetector generates an electrical signal based on the reflected light. The electrical signal is then transmitted to a processor or computer for analysis, such as signal processing, to determine if a color change has occurred and the concentration of the gas component in the breath sample based on any color change. Additionally, the processor may refer to calibration data or a calibration curve for the system in computing the concentration of the gas component in the breath sample. The calibration data may be stored in the processor or elsewhere on the system. For example, each indicator unit may have its own particular calibration data. As such, each indicator unit may include stored calibration data that can be accessed by the processor for quantitative gas concentration calculations. The calibration data may be stored in a flash memory device on the indicator unit.

Once the gas component concentration is determined, the concentration may be displayed on a monitor. The quantitative colorimetric system may include a display monitor or, alternatively, the system may communicate the information to a remote monitor through a wired or wireless connection. The display can be a mobile display device, such as a smartphone or tablet, or a non-mobile display device, such as a television.

Any measurements for a patient may be stored locally on the device or remotely for later retrieval. This allows the patient as well as medical professionals to monitor the tested component's levels in the patient's breath.

In some embodiments, a measuring session includes one or more of the following steps:.

In addition to the above, various aspects of the inventions are directed to a breathing therapy system for non-invasively and non-pharmaceutically treating various conditions include panic disorder, anxiety, general anxiety disorder, obsessive-compulsive disorder, social phobia, depression, apnea, migraines, epilepsy, asthma, post-traumatic stress disorder, and hypertension. Some embodiments described herein are directed toward breathing therapy to treat a disorder or disease. For example, quantitative colorimetric carbon dioxide detection system described can be used to measure and modify a user's CO<NUM> levels to provide treatment for any number of disorders or illnesses.

In some cases, a patient's end-tidal CO<NUM> levels are monitored and/or modified. Generally, end-tidal CO<NUM> refers to the carbon dioxide levels measured in a user's exhaled airflow. <FIG> provides a general representation of the expiration and inspiration pattern for respiration where end-tidal CO<NUM> is measured at the peak <NUM> of expiration. End-tidal CO<NUM> levels can be measured in partial pressure units such as mmHg. Additionally, CO<NUM> levels in general, including end-tidal CO<NUM>, can be quantitatively measured in terms of concentration. Concentration may be measured in volume percent or pressure. In some embodiments, the carbon dioxide values may be measured in one unit and converted to another. For example, partial pressure values may be derived from measured concentration percentages. In further variations, the carbon dioxide values may be measured in pressure values directly.

As can be appreciated, measuring and modifying end-tidal CO<NUM> levels may be described as a non-limiting example of one treatment application for the quantitative colorimetric gas component detection systems described. CO<NUM> levels measured may include (but is not limited to) end-tidal CO<NUM>. Similarly, CO<NUM> may be quantified in terms of partial pressure units (e.g. mmHg) as illustrated in examples described. However, it is to be understood that any units may be used to quantify the amount of CO<NUM> measured from a gas sample (including volume percentage) for the purposes of this disclosure.

As described, some embodiments contemplated provide for a breathing therapy system having a device for measuring the concentration of components in a user's exhaled air. The device may display the measured components in any suitable units including pressure units. The device may include sensors for measuring CO<NUM> levels in the expired air as well as sensors for measuring other parameters of the user such as breathing rate, pulse rate, blood oxygen saturation level, etc..

For illustration purposes, <FIG> shows a general quantitative colorimetric capnometer having a main sensing unit <NUM> and a connector <NUM>. The main sensing unit <NUM> may include any of the components described such as a colorimetric indicator and an electro-optical sensing assembly. In some embodiments, the breathing system <NUM> may further include a display component <NUM> for providing measured end-tidal CO<NUM> levels, breathing rate, or any other measured/sensed user information. The display component <NUM> may provide numerical values for the measured/sensed information and/or provide a graph showing the user's respiration patterns.

Referring again to <FIG>, some embodiments provide for CO<NUM> measuring devices that record measured parameters during use. The device, such as a quantitative colorimetric capnometer or an IR absorption spectroscopy sidestream capnometer, may record the information locally within the device for later retrieval by the user or a medical professional. In other embodiments, the capnometer may communicate the user's information through a wired or wireless connection to a centralized database. The capnometer may electronically communicate the user's information to a mobile device such as a smart phone, tablet, laptop, etc. In such cases, the mobile device <NUM> may electronically receive the user's information, process the information, and provide the user and clinician/caregiver with a summary or assessment of the user's progress.

In further embodiments, the capnometer may communicate the user's information to the mobile device <NUM> during a patient's use. The mobile device <NUM> processes the information in real-time or dynamically to provide the user with a graphical representation of respiratory gas exchange parameters. <FIG> shows graphical representation of a user's end-tidal carbon dioxide levels and breathing rate per minute during capnometer use. The mobile device <NUM> can receive user information from the capnometer and display such information during use (and/or after use). Alternatively, in some embodiments, the patient's respiration information is measured but not displayed.

To provide breathing therapy, the quantitative colorimetric devices described include a stored breathing therapy protocol or treatment program that is executed while the patient provides breath samples. For example, the system or device may include a processor with a stored breathing protocol that activates based on the concentration or pressure of end-tidal CO<NUM> measured in the patient's breath sample. The program uses visual or audio cues to guide the patient to a target breathing rate and/or CO<NUM> concentration/pressure. The visual or audio information or cues are presented to the user through a display screen and/or audio device such as headphones. In some cases, the patient attachment would include a microphone allowing the user to record audible comments (time stamped) during the therapy session thus eliminating the need for manual note taking. As described above, the display screen or audio device may be integrated with the measuring components. (See <FIG>).

According to the invention, systems are provided that treat a disorder or illness by helping a user modify end-tidal CO<NUM> levels in exhaled air. A user is guided either visually or audibly to attain or maintain target end-tidal CO<NUM> levels in exhaled breath. In some cases, the desired target end-tidal CO<NUM> level is between about <NUM> mmHg and about <NUM> mmHg.

End-tidal CO<NUM> modification can be accomplished in several ways according to the described embodiments. For example, as shown in <FIG>, some embodiments provide for a three-stage therapy for modifying end-tidal CO<NUM>. In such embodiments, the first stage is a baseline stage <NUM> where the patient's baseline data is collected. In some cases, the first stage lasts about two minutes. A second stage is a pacing stage <NUM> during which the patient is instructed on how to modify breathing patterns. The pacing stage may include instructions to adjust breathing rate, exhalation length, inhalation length, volume of air intake for inhalation; and/or target carbon dioxide levels. The pacing stage is designed based on the patient's baseline data. In some cases, the second stage lasts about ten minutes or less. Following the second stage, a third stage may be used to help patients practice pacing methods. For example, the patient may attempt to maintain a breathing pattern without instructions or cues available in the second stage. In some cases, the patient may refer to biofeedback to help the patient maintain a target breathing pattern in the third stage. Biofeedback can include monitoring carbon dioxide levels and respiratory rate. In some embodiments, the third stage is a transition stage <NUM> that lasts about five minutes or less. Additional details for each of the three stages are provided in the following sections.

During the baseline stage, the patient may sit quietly and breathe normally with eyes closed. Patient data is collected to show the patient's respiration parameters prior to any instruction or modification. The patient's respiration parameters may be measured and/or recorded by a capnometer or a breathing therapy system as shown in <FIG> and <FIG>. Additionally, other patient parameters (e.g. oxygen saturation, blood pressure, heart rate, etc.) may be measured or monitored during the baseline stage. In some cases, the baseline stage may last two-minutes. In other embodiments, the baseline stage may be shorter or longer as needed to adequately collect the patient's pre-instruction and pre-modification parameters.

The user's information may be stored and/or electronically communicated from a capnometer to a central database or to a mobile device. In other cases, a therapist may be on-site to receive the collected data. Where the capnometer communicates the user's data to a central database or mobile device, the database or mobile device may perform an algorithm to assess an appropriate breathing therapy for the user. For example, if the user's end-tidal CO<NUM> levels are measured to be below a desired target range, the algorithm may provide instructions that the user should increase end-tidal CO<NUM> through breathing exercises. If a user has a breathing rate of <NUM> breaths per minute (bpm), the algorithm may provide instructions that the user should reduce breathing rate. In other embodiments, the instructions may request that the user adjust breathing rate to match a target rate.

Once the appropriate therapy is determined by the algorithm or by a therapist, the patient enters the second stage or pacing stage. The pacing stage provides for visual or audio guidance to help the patient modify breathing patterns, habits, and end-tidal CO<NUM>. For example, in some embodiments where a mobile device is used, the mobile device may play a set of audio tones, visual cues, pacing tones, audible instructions or music to guide the patient's cyclic rhythm of inspiration and expiration.

The audio tones may help the patient pace his breathing with target breathing patterns. For example, the audio tones may increase in volume or pitch to indicate inspiration and lower in volume or pitch to indicate expiration. Moreover, the duration of the audio tones during inspiration may be shorter than the audio tones during expiration or vice versa to indicate the length of inhalation and exhalation. In some embodiments, rising tones indicate inspirations and falling tones indicate expiration. In other embodiments, the audio tones or tone patterns include silence which indicates a pause between exhalation and inhalation or inhalation and exhalation.

Additionally, the breathing cues may guide the patient to a modified respiratory rate. Because a patient may present with a higher breathing rate to start, embodiments described provide exercises to gradually reduce breaths per minute to a target range. For example, during the baseline stage, the patient may present with <NUM> bpm (breaths per minute). The capnometer collects this information and communicates the data to a mobile device. The mobile device receives the user data during the baseline stage and operates an appropriate therapy protocol in the pacing stage step. The therapy protocol (or second stage) may entail a ten-minute period during which the patient breathes along with pacing or audio tones (e.g. tone patterns) to guide them in their breaths per minute.

In some embodiments, tones patterns guide the patient to adjust his breaths per minute to <NUM> bpm, <NUM> bpm, <NUM> bpm, or <NUM> bpm, etc. Although <NUM>, <NUM>, <NUM>, <NUM> breaths per minute are given as examples, it can be appreciated that depending on a patient's baseline, modifications of the pacing tones may be required. For example, the tone pattern can be modulated to correspond to a respiration rate of <NUM> breaths per minute in a first therapy session and to rates of <NUM>, <NUM>, and <NUM> breaths per minute in successive sessions. However, if the patient's baseline is <NUM> bpm, then the treatment may begin with tone patterns for <NUM> bpm. In other cases, it may be desirable to use <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> bpm patterns. In another example, the patient's breath may be below a target bpm. The tone patterns may guide the patient to increase bpm. In some embodiments the therapy guides the patient to a respiration rate of about <NUM> bpm to about <NUM> bpm.

Additionally, in some variations, the breathing cues will instruct the user to adjust volume of inhaled air to match a target volume. In some cases, the user will be instructed to reduce volume of inhaled air. The user may be taught how to breathe air such that the volume of air is at or near a target level. In some cases, reducing the volume of inhaled air can be used to treatment a disorder, condition, and/or disease. Additionally, one way to measure the volume of air in a breath is by measuring the end-tidal CO<NUM> levels.

Visual breathing guidance may be used in combination or alone for guiding the user's breathing pattern. For example, colors, lines, shapes, words, letters, pictures, etc. may be used to indicate length of inhalation or exhalation and pauses in between. Moreover, visual cues may be used to teach the user how to attain or maintain desired end-tidal CO<NUM> levels, respiratory rate, etc. For example, a graph measuring end-tidal CO<NUM> levels may be shown to encourage the user to attain or maintain a target level of end-tidal CO<NUM>.

As described, instructing the user to modify breathing pattern may lead to increased end-tidal CO<NUM> levels. In some embodiments, the end-tidal CO<NUM> levels are increased or maintained at about <NUM> mmHg to about <NUM> mmHg by decreasing to or maintaining breaths per minute at about <NUM> bpm.

Upon completion of one or more pacing stages, the patient may enter a transition stage. The transition stage allows the patient to practice the breathing patterns used in the pacing stage without any outside guidance. However, alternatively, the pacing tones and visual/audio cues may also be provided during the transition stage depending on the patient's needs. In some cases, even where the breathing cues are provided, the patient may be instructed not to follow or rely upon the cues.

Additionally, in the transition stage, the patient may regularly or sporadically check his measured parameters including end-tidal CO<NUM> levels and respiratory rate to monitor progress. Patients may also be encouraged to attain or maintain target breathing rate and end-tidal CO<NUM> levels by monitoring measured parameters.

In some embodiments, the treatment described takes places over the course of four weeks. The three-stage exercise (baseline, pacing, and transition) may be repeated two or more times every day for multiple weeks. In some cases, the three-stage exercise is performed for one week or more, including four weeks. Each week the pacing stage may be altered based on the patient's progress. For example, if the patient has achieved a <NUM> bpm breathing rate, the pacing stage protocol may be changed to guide the patient to a <NUM> bpm breathing rate. Generally, the pacing stage will change each week. However, it can be appreciated that depending on the patient's progress, the treatment timeline may be modified accordingly. In some embodiments, the baseline duration may be about two minutes, the pacing duration about ten minutes, and the transition duration about five minutes.

In further embodiments, the tone patterns or breathing therapy may include techniques from (<NUM>) Capnometry Assisted Respiratory Therapy (CART). A therapy protocol developed by <NPL>; (<NUM>) <NPL>; and (<NUM>) the Buteyko Method.

As described, in some embodiments, the breathing therapy treatment may be executed by a system utilizing software (e.g. mobile app) that can be downloaded to a patient's personal computing device. For example, software for the therapy can be downloaded and executed on a mobile device that electronically communicates with a capnometer. The software or program may provide for immediate breathing feedback to the patient through audio guidance and visual displays, allowing the patient to adjust his or her respiration rate and end-tidal CO<NUM> levels. The software or program may store training sessions and training session results for review by a medical professional or the patient. such treatment protocols, softs or programs are not encompassed by the wording of the claims.

The program may display a graph showing the end-tidal CO<NUM> levels and breathing rate with goal lines for target values. <FIG> shows goal line (dashed) CO<NUM> pressure at <NUM> mmHg and goal line (dashed) 13bpm for breathing rate. In some embodiments, the system may provide the patient with advice or tips during the session on how to reach goals such as raising end-tidal CO<NUM>. As shown in <FIG>, current CO<NUM> levels are indicated in a blue box that shows the CO<NUM> level of the patient's last breath. The blue line leading up to the blue box shows a record of the patient's CO<NUM> level during the current breathing session. The white box next to the Current CO<NUM> level shows the Target CO<NUM> level, which is <NUM>-<NUM> mmHg ("millimeters of Mercury") in the example. The number in the green box shows the current Respiration Rate (RR). The green line leading up to the green box shows a record of the patient's RR during the current breathing session. The white box next to the Current Respiration Rate shows the Target Respiration Rate.

In further embodiments, the system may alert the user if breathing rate or end-tidal CO<NUM> levels exceed a safety limit, which may include being above or below a safety limit. The system may also alert the user if the capnometer has become disconnected from the system. The graphical representation may also include icons showing the operability of the capnometer device including icons for battery use, sensor activation, and Bluetooth connectivity. The graphical representation may also include graphical user interface components for the user to manipulate (e.g. click) to receive breathing therapy instructions.

In further embodiments, the program may include a calibration protocol to prepare the device for measuring a patient's breath. In some cases, the program or software may automatically calibrate the system as described above (e.g. span and zero calibration). In other cases, the calibration software may calibrate based on ambient air in the patient's environment. Additionally, the program or software may use GPS to determine the altitude of the patient's location. Altitude may be factored into the patient's breathing therapy. For example, the calculation for CO<NUM> level may take into account barometric pressure. Altitude can be used to calculate (and get a close approximation) of barometric pressure.

Additionally, during treatment, the patient can view breathing rate, end-tidal CO<NUM> levels, or any other collected data/parameters for feedback and guidance on progress. The patient can use the display on the capnometer or on a connected mobile device to track progress. In some embodiments, the visual or audio cues for breathing pattern learning, capnometer, display, and any other components for treatment are contained in a single device. The device may include a processor for executing a pre-programmed treatment session. The processor may also electronically receive measurements from the capnometer for processing or display.

Claim 1:
A breathing therapy system, the system comprising:
a quantitative colorimetric detection system (<NUM>, <NUM>, <NUM>) comprising:
a gas inlet (<NUM>, <NUM>) configured to receive at least a portion of a user's exhaled air; and
a colorimetric indicator (<NUM>, <NUM>) in fluid communication with the gas inlet (<NUM>, <NUM>) for measuring a user's end-tidal CO<NUM> levels based on a color change of the colorimetric indicator (<NUM>, <NUM>) resulting from exposure to the user's exhaled air; and one or more processors programmed to:
during a first time period: determine the user's end-tidal CO<NUM> levels based on the color change of the colorimetric indicator (<NUM>, <NUM>) resulting from exposure to the user's exhaled air; and determine the user's respiration rate;
determine a therapy protocol based on the user's end-tidal CO<NUM> levels determined during the first time period or based on the user's respiration rate determined during the first time period; and
during a second time period: outputting in accordance with the determined therapy protocol a set of visual and/or audio cues from the quantitative colorimetric detection system (<NUM>, <NUM>, <NUM>) with instructions for the user to adjust their breathing pattern to coincide with the cues to thereby modify the user's exhaled CO<NUM> levels; and
a display screen (<NUM>, <NUM>, <NUM>, <NUM>) for outputting the set of visual cues and/or an audio device (<NUM>) for outputting the set of audio cues.