Breath sample collection device

Abstract

An apparatus and method for collecting exhaled breath samples is provided, the apparatus having an exhaled breath input interface configured to receive exhaled breath and a container connected to the exhaled breath input interface for receiving at least a portion of the exhaled breath, the container having a cavity of controllable volume and at least one controller configured to control the volume of the cavity to increase at a volumetric rate at most equal to the flow rate of the exhaled breath received by the exhaled breath input interface.

Description

[Technical Field]

[0001] FIELD OF THE INVENTION This disclosure relates generally to sample collection systems, and more particularly to devices and methods for collecting exhaled breath samples. [Background technology]

[0002] Breath sampling has traditionally been performed by collecting breath from a patient into a large container, from which the breath sample is then extracted and transferred directly to an analyzer.

[0003] More recently, breath samples have been collected in breath sample collection devices known as sorbent tubes or thermal desorption tubes. A sorbent tube is a tube containing a solid adsorbent material with a large surface area. When a gas sample is passed through the sorbent tube, some components, such as oxygen and carbon dioxide, flow out the opposite end of the tube, while other components are adsorbed by the sorbent. This allows many components in the breath sample to be trapped in the sorbent while the largest volume of components flows out, thereby concentrating the breath sample. As a result, most of the components in the breath sample can be collected in a smaller volume. Summary of the Invention [Problem to be solved by the invention]

[0004] However, there are many problems with devices that allow a person to directly fill these sorbent tubes. Human breath contains a significant amount of humidity that can interfere with breath collection in this mode. This humidity can cause condensation to form on the inside of the conduit that directs the breath to the sorbent tube. This condensation attracts many of the breath components that freely attach to water molecules. As a result, many of the breath sample components do not reach the sorbent tube and therefore do not appear in at least part of the breath sample that is analyzed.

[0005] Another problem is that the sorbent tube captures breath components more effectively at a particular flow rate of breath through the sorbent tube. The rate at which breath flows through the sorbent tube in prior art devices is driven by the rate at which a person breathes into these devices. This leads to the loss of a portion of the breath sample. [Means for solving the problem]

[0006] In one aspect, an apparatus for collecting exhaled breath samples is provided, comprising: an exhaled breath input interface configured to receive exhaled breath; a container connected to the exhaled breath input interface for storing at least a portion of the exhaled breath; and at least one controller configured to control flow of at least a portion of the exhaled breath from the container to at least one sorbent tube connected to the container asynchronously with the receipt of the exhaled breath.

[0007] The container may have a cavity in which at least a portion of the exhaled gas is stored, the volume of the cavity being controllable. The volume of the cavity may be controllable by the at least one controller. The container may include a piston chamber having a piston disposed therein, the position of the piston controlling the volume of the cavity. The at least one controller may be configured to actuate the piston to increase the volume of the cavity as the at least a portion of the exhaled gas is received.

[0008] The device further comprises: a valve intermediate the breath input interface and the container; The system may include a first conduit system connecting the exhaled breath input interface and the valve, and a second conduit system connecting the container to the at least one sorbent tube. The at least one controller may be configured to control the valve to close and to control actuation of the piston to force the at least a portion of the exhaled breath through a subset of the at least one sorbent tube. A tube inlet valve may be disposed between the container and each of the at least one sorbent tube. The at least one controller may be configured to control each of the at least one tube inlet valves to select the subset of the at least one sorbent tube through which the at least a portion of the exhaled breath flows.

[0009] The subset may be a first subset, and the apparatus may further include an inlet valve disposed along the second conduit system between an inlet and the vessel, wherein the at least one controller may be configured to open the inlet valve and control actuation of the piston to draw air through the inlet and into the cavity, and the at least one controller may be configured to close the inlet valve and propel the entrained air from the cavity through the second conduit system. The at least one controller may control actuation of the piston to propel the entrained air through a second subset of the at least one sorbent tube. A tube inlet valve may be disposed between the vessel and each of the at least one sorbent tubes. The at least one controller may be configured to control each of the at least one tube inlet valves to select the second subset of the at least one sorbent tube through which the entrained air is flowed.

[0010] The container may include an at least partially flexible, collapsible receptacle. The device may further include a valve intermediate the breath input interface and the container, a first conduit system connecting the breath input interface and the valve, and a second conduit system connecting the container to the at least one sorbent tube. The device further includes a pump controlled by the at least one controller and capable of propelling the at least a portion of the exhaled breath from the container through a subset of the at least one sorbent tube. Tube inlet valves may be disposed between the container and each of the at least one sorbent tubes. The at least one controller may be configured to control each of the at least one tube inlet valves to select the subset of the at least one sorbent tube through which the at least a portion of the exhaled breath flows.

[0011] The pump may be disposed between the valve and the container, and the at least one controller may be configured to control the pump to draw the at least a portion of the exhaled breath into the container.

[0012] The subset may be a first subset, and the device may further include an inlet valve disposed along the second conduit system between an inlet and the container, wherein the at least one controller may be configured to close the inlet valve and control the pump to flow air from the container through the second subset of the at least one sorbent tube. The at least one controller may be configured to open the inlet valve and control the pump to flow air through the inlet and into the cavity. A tube inlet valve may be disposed between the container and each of the at least one sorbent tube. The at least one controller may be configured to control each of the at least one tube inlet valve to select the first subset of the at least one sorbent tube through which the at least a portion of the exhaled breath is flowed.

[0013] The device may further include a valve intermediate the breath input interface and the container, and a first conduit system connecting the breath input interface and the valve. The at least one controller may be configured to control the valve to close when a target volume of the breath is captured within the container, thereby controlling the volume of the container to propel at least a portion of the breath through a subset of the at least one sorbent tube. The at least one controller may be configured to control the volume of the container to decrease at one of at least two breath flow rates at which the at least one controller can control the volume of the container to propel the breath through the subset of the at least one sorbent tube.

[0014] In another aspect, a method for collecting exhaled breath samples is provided, the method including receiving exhaled breath via an exhaled breath input interface, collecting at least a portion of the exhaled breath in a container connected to the exhaled breath input interface, and controlling via at least one controller a flow rate of the at least a portion of the exhaled breath from the container to at least one sorbent tube connected to the container asynchronously with the receipt of the exhaled breath.

[0015] The storing step may include storing the at least some of the exhaled breath in a cavity of the container, wherein a volume of the cavity may be controllable. The method may further include controlling the volume of the cavity via the at least one controller. The method may further include actuating a piston disposed in a piston chamber of the container via the at least one controller, wherein a position of the piston controls the volume of the cavity. The method may further include actuating the piston to increase the volume of the cavity when receiving the at least some of the exhaled breath. The method may further include controlling a flow of the at least some of the exhaled breath through a valve intermediate the breath input interface and the container, wherein a first conduit system connects the breath input interface and the valve and a second conduit system connects the container to the at least one sorbent tube. The method may further include controlling, via the at least one controller, the valve to close and controlling actuation of the piston to propel the at least portion of the exhaled gas through a subset of the at least one sorbent tube. A tube inlet valve may be disposed between the container and each of the at least one sorbent tubes, and the method may further include controlling each of the at least one tube inlet valve to select the subset of the at least one sorbent tube through which the at least portion of the exhaled gas is passed.

[0016] The method may further include controlling, via the at least one controller, to close the valve, controlling to open an inlet valve separating the container from an inlet, controlling actuation of the piston to draw air through the inlet and into the cavity, controlling the inlet valve to close, and controlling actuation of the piston to propel the entrained air from the cavity through the second conduit system.

[0017] The method may further include controlling actuation of the piston to propel the entrained air through a second subset of the at least one sorbent tube. A tube inlet valve may be disposed between the vessel and each of the at least one sorbent tube. The method may further include controlling each of the at least one tube inlet valve to propel the entrained air through the at least one sorbent tube through which the entrained air is flowing. The method may include selecting the second subset of nodes.

[0018] The container may include an at least partially flexible, collapsible receptacle. The method may further include controlling the flow of the at least a portion of the exhaled breath through a valve intermediate the exhaled breath input interface and the container, wherein a first conduit system connects the exhaled breath input interface and the valve, and a second conduit system connects the container to the at least one sorbent tube. The method may further include controlling a pump to flow at least a portion of the exhaled breath from the container through a subset of the at least one sorbent tube. A tube inlet valve may be disposed between the container and each of the at least one sorbent tube. The method may further include controlling each of the at least one tube inlet valves to select the subset of the at least one sorbent tube through which the at least a portion of the exhaled breath will flow.

[0019] The pump may be disposed between the valve and the container, and the method may further include controlling the pump to draw the at least a portion of the exhaled air into the container.

[0020] The subset may be a first subset, and the method may further include closing the valve, opening an inlet valve intermediate the inlet and the container, and controlling the pump to flow air through a second subset of the at least one sorbent tube. The method may further include opening an inlet valve and controlling the pump to flow air through the inlet and into the cavity. A tube inlet valve may be disposed between the container and each of the at least one sorbent tube. The method may further include controlling each of the at least one tube inlet valve to select the subset of the at least one sorbent tube through which the at least a portion of the exhaled gas is flowed.

[0021] The method may further include controlling a flow of the exhaled breath from a first conduit system connected to the breath input interface through a valve to the container. The method may further include controlling the valve to close and controlling the volume of the container to flow at least a portion of the exhaled breath through a subset of the at least one sorbent tube when a target volume of the exhaled breath is captured in the container. During the volume control step, the volume may be controlled to decrease at one of at least two exhalation flow rates at which the volume may be controlled to decrease to propel the exhaled breath through the subset of the at least one sorbent tube.

[0022] In a further aspect, an apparatus for collecting breath samples is provided, the apparatus comprising: a breath input interface configured to receive exhaled breath; a metering device configured to measure constituent levels in the received exhaled breath; a first conduit system extending from the breath input interface and connected to at least one breath sample reservoir; a valve disposed along the first conduit system to control flow of the exhaled breath toward the at least one breath sample reservoir; and at least one controller configured to determine whether the constituent levels are within constituent level target ranges; determine whether a rate of change of the constituent levels is within a constituent level rate target range; and control the valve to open based at least in part on whether the constituent levels are within the constituent level target ranges and whether the rate of change is within the constituent level rate target ranges.

[0023] The metering device may be a capnometer and the constituent level may be a carbon dioxide level; The component level target ranges can be carbon dioxide level target ranges, and the component level rate of change target ranges can be carbon dioxide level rate of change target ranges. The device can further include a flow meter configured to measure a flow rate of the exhaled breath being received, and the at least one controller configured to control the valve to open based at least in part on the measured flow rate being within a flow rate target range. The device can further include a display, and the at least one controller configured to control the display to present a flow rate notification on the display.

[0024] The device may further include at least one optical element, the at least one controller configured to control the at least one optical element to cause the at least one optical element to present a flow notification.

[0025] The device may further include a speaker, the at least one controller being configured to control the speaker to play an audible flow rate notification via the speaker.

[0026] The component level target range may span between a component level minimum threshold and an infinite upper limit.

[0027] The component level rate of change target range may span between an infinite lower limit and a component level rate of change maximum threshold.

[0028] The flow rate target range may span between a minimum flow rate threshold and an infinite upper limit.

[0029] The at least one controller may be configured to monitor the component levels after opening the valve.

[0030] The device may further include a flow meter configured to measure a flow rate of the exhaled breath being received, and the at least one controller is configured to monitor the flow rate after opening the valve and control the valve to close based at least in part on the measured flow rate being within a flow rate terminal range.

[0031] In yet another aspect, a method for collecting exhaled breath samples is provided, the method including receiving exhaled breath via a breath input interface having a first conduit system extending therefrom toward at least one breath sample reservoir, a valve arranged to control movement of the exhaled breath from the first conduit system to the at least one breath sample reservoir, and including the steps of determining, via at least one controller, whether the constituent levels in the received exhaled breath are within constituent level target ranges; determining that a rate of change of the constituent level is within a constituent level rate change target range; and controlling the valve to open based at least in part on whether the constituent level is within the constituent level target range and whether the rate of change is within the constituent level rate change target range.

[0032] The constituent level may be a carbon dioxide level, the constituent level target range may be a carbon dioxide level target range, and the constituent level rate of change target range may be a carbon dioxide level rate of change target range.

[0033] The method may further include measuring a flow rate of the exhaled breath being received, and capturing is performed at least in part based on the measured flow rate being within a flow rate target range. The method may further include controlling a display to cause the display to present a flow rate notification. The method may further include at least one The method may include controlling an optical element to cause the at least one optical element to provide a flow rate indication.

[0034] The method may further include controlling a speaker to play an audible flow rate notification through the speaker.

[0035] The carbon dioxide level target range may span between a minimum carbon dioxide level threshold and an infinite upper limit.

[0036] The carbon dioxide level rate of change target range may span between an infinite lower limit and a carbon dioxide level rate of change maximum threshold.

[0037] The flow rate target range may span between a minimum flow rate threshold and an infinite upper limit.

[0038] The method may further include monitoring the carbon dioxide level after opening the valve.

[0039] The method may further include measuring a flow rate of the exhaled breath being received, wherein the at least one controller is configured to monitor the flow rate after opening the valve and control the valve to close based at least in part on the measured flow rate being within a flow rate terminal range.

[0040] In yet another aspect, an apparatus for collecting breath samples is provided, the apparatus comprising: a breath input interface configured to receive exhaled breath; a first conduit system connected to the breath input interface; a valve configured to control fluid communication between the first conduit system and at least one breath sample reservoir configured to store an exhaled breath sample; an air circulation system configured to circulate air through the first conduit system upon completion of a first received exhaled breath; and at least one controller configured to control the valve upon completion of the first received exhaled breath based at least in part on a humidity level within the first conduit system.

[0041] The at least one controller may be configured to control the valve based at least in part on whether the rate of change of the humidity level is within a humidity level change target range. The at least one controller may be configured to close the valve to inhibit passage of subsequent exhaled breath from the first conduit system to the at least one breath sample reservoir until the rate of change of the humidity level in the first conduit system is within the humidity level change target range. The device may further include a hygrometer connected to the first conduit system and configured to measure the humidity level in the first conduit system. The device may further include a notification system for indicating when the rate of change of the humidity level in the first conduit system is within the humidity level change target range.

[0042] The first conduit system may include an inhalation conduit extending between the inhalation input interface and the valve, and the hygrometer may be connected to an exhaust conduit of the first conduit system branching from the inhalation conduit. The fluid circulation system may be directly connected to the exhaust conduit. The exhaust conduit may include a flow meter configured to measure a flow rate along the exhaust conduit.

[0043] The at least one controller may be configured to control the valve based at least in part on whether the humidity level is within a humidity level target range. The valve may be configured to close to inhibit passage of subsequent exhaled breath from the first conduit system to the at least one breath sample reservoir until the exhaled breath is within a target range.

[0044] In another aspect, a method for collecting exhaled breath samples is provided, the method including receiving exhaled breath via an exhaled breath input interface connected to a first conduit system; collecting at least a portion of the exhaled breath via at least one exhaled breath sample reservoir connected to the first conduit system; detecting completion of the exhaled breath; closing a valve between the first conduit system and the at least one sorbent tube upon detecting the completion of the exhaled breath; circulating air through the first conduit system connected to the exhaled breath input interface after detecting the completion of the exhaled breath; monitoring a humidity level within the first conduit system; and controlling, via at least one controller, the valve based at least in part on the humidity level within the first conduit system.

[0045] The controlling step may include determining whether the rate of change of the humidity level is within a target humidity level change range. The method may further include controlling the valve to close and inhibit subsequent passage of exhaled breath from the first conduit system to the at least one breath sample reservoir until the rate of change of the humidity level in the first conduit system is within the target humidity level change range. The method may further include measuring the humidity level in the first conduit system via a hygrometer connected to the first conduit system. The method may further include indicating when the rate of change of the humidity level is within the target humidity level change range.

[0046] The first conduit system may include an inlet conduit extending between the inlet conduit and the valve, and the measuring of the humidity level is performed by a hygrometer connected to an exhaust conduit of the first conduit system branching from the inlet conduit. The fluid circulation system may be directly connected to the exhaust conduit. The method may further include measuring a flow rate along the exhaust conduit via a flow meter along the exhaust conduit.

[0047] The controlling step may include determining whether the humidity level is within a target humidity level range. The method may further include controlling the valve to close and inhibit passage of subsequent exhaled breath from the first conduit system to the at least one breath sample reservoir until the humidity level in the first conduit system is within the target humidity level range.

[0048] In a further aspect, there is provided an apparatus for collecting exhaled breath samples, the apparatus comprising: an exhaled breath input interface configured to receive exhaled breath; a first conduit system connected to the exhaled breath input interface; and at least one exhaled breath sample reservoir connected to the exhaled breath input interface via an exhaled breath intake conduit of the first conduit system extending between the exhaled breath input interface and the exhaled breath collection system, the at least one exhaled breath sample reservoir configured to capture at least a portion of the exhaled breath and further comprising at least one metering device for measuring at least one characteristic, the at least one metering device being positioned along the exhaust conduit of the first conduit system branching from the exhaled breath intake conduit.

[0049] The at least one metering device may include a flow meter that measures the flow rate of the exhaled breath along the exhaust conduit of the first conduit system. The at least one metering device may include a capnometer disposed along the exhaust conduit of the first conduit system that measures the carbon dioxide level in the exhaled breath.

[0050] The at least one metering device may include a hygrometer disposed along the exhaust conduit of the first conduit system for measuring a humidity level within the exhaust conduit, and the device may further include a pump disposed along the exhaust conduit of the first conduit system for flowing air through the exhaust conduit.

[0051] In yet another aspect, a method for collecting exhaled breath samples is provided, the method including the steps of receiving exhaled breath via an exhaled breath input interface, capturing the exhaled breath via the exhaled breath collection system, the exhaled breath including a first conduit system connected to the exhaled breath input interface and further connected to the exhaled breath input interface via an exhaled breath inlet conduit of the first conduit system extending between the exhaled breath input interface and the exhaled breath collection system, and measuring at least one characteristic along an exhaust conduit of the first conduit system branching from the exhaled breath inlet conduit via at least one metering device disposed along the exhaust conduit.

[0052] The at least one metering device may include a flow meter, and the at least one characteristic may include a flow rate of the exhaled breath along the exhaust conduit.

[0053] The at least one metering device may include a capnometer, and the at least one characteristic may include a carbon dioxide level in the exhaled breath.

[0054] The method may further include measuring a humidity level along the exhaust conduit via a hygrometer positioned along the exhaust conduit of the first ducting system. The method may further include flowing air through the exhaust conduit via a pump positioned along the exhaust conduit.

[0055] In yet another aspect, an apparatus for collecting breath samples is provided, the apparatus comprising: an exhaled breath input interface configured to receive exhaled breath; a container connected to the exhaled breath input interface for receiving at least a portion of the exhaled breath, the container having a cavity of a controllable volume; and at least one controller configured to control the volume of the cavity to increase at a volumetric rate at most equal to a flow rate of the exhaled breath received by the exhaled breath input interface.

[0056] A first conduit system's exhalation intake conduit can extend from the exhalation input interface toward the container, and the first conduit system's exhaust conduit branches off from the exhalation collection section at a first end and has an outlet at a second end. The device can further include a flow meter arranged to measure a flow rate along the exhaust conduit. A volumetric increase rate of the volume of the container can be proportional to the flow rate along the exhaust conduit. The volume of the container can be directly mechanically controllable by the at least one controller. The container can include a piston chamber having an actuable piston disposed therein, the position of the piston within the piston chamber defining the volume of the cavity. The device can further include a valve arranged to control movement of the exhaled breath into the piston chamber. The device can further include at least one sorbent tube connected to the container, and the at least one controller is configured to control the valve to close and to control actuation of the piston to propel the exhaled breath through the at least one sorbent tube and into the cavity.

[0057] The container may include an at least partially flexible, collapsible receptacle, the device further configured intermediate the exhaled breath input interface and the container to propel the exhaled breath into the at least partially flexible, collapsible receptacle at the rate of volumetric increase. The device may further include at least one sorbent tube connected to the at least partially flexible collapsible receptacle, the at least one controller configured to control the pump to propel the exhaled gases through a subset of the at least one sorbent tube and into the cavity. The device may further include a valve positioned to control movement of the exhaled gases into the piston chamber.

[0058] The device may further include a valve arranged to control movement of the exhaled breath into the piston chamber. The device may further include a metering device arranged to measure a constituent level in the exhaust conduit, and the at least one controller may be configured to determine whether the constituent level is within a constituent level target range, determine whether the rate of change of the constituent level is within a constituent level rate target range, and control to open the valve based at least in part on whether the constituent level is within the constituent level target range and whether the rate of change is within the constituent level rate target range. The metering device may be a capnometer, the constituent level may be a carbon dioxide level, the constituent level target range may be a carbon dioxide level target range, and the constituent level rate change target range may be a carbon dioxide level target range.

[0059] The device may further include a first conduit system inlet / outlet conduit extending from the inlet / outlet interface toward the container and a flow meter disposed to measure the flow rate of the exhaled breath along the inlet / outlet conduit. The rate of volumetric increase of the volume of the container may be proportional to the flow rate along the inlet / outlet conduit. The volume of the container may be directly mechanically controllable by the at least one controller. The container may include a piston chamber having an actuable piston disposed therein, the position of the piston within the piston chamber defining the volume of a cavity. The device may further include a valve disposed to control movement of the exhaled breath into the piston chamber. The device may further include at least one sorbent tube connected to the container, the at least one controller configured to control the valve to close and to control actuation of the piston to propel the exhaled breath within the cavity through a subset of the at least one sorbent tube.

[0060] The container may include an at least partially flexible, collapsible receptacle, and the device may further include a pump configured intermediate the breath input interface and the container, propelling the exhaled breath into the at least partially flexible, collapsible receptacle at the volumetric rate of increase.

[0061] In yet another aspect, a method for collecting a breath sample is provided, the method comprising the steps of receiving exhaled breath via a breath input interface; and collecting at least a portion of the exhaled breath in a container connected to the breath input interface, the container having a cavity of a controllable volume; and controlling, via at least one controller, the volume of the container to increase at a rate of volume increase at most equal to a flow rate of the exhaled breath received by the breath input interface.

[0062] An exhalation intake conduit of a first conduit system may extend from the exhalation input interface toward the container, and an exhaust conduit of the first conduit system may branch from an exhalation collection unit at a first end thereof and have an outlet at a second end thereof. The method may further include measuring a flow rate along the exhaust conduit via a flow meter. The rate of volumetric increase of the volume of the container may be proportional to the flow rate. The method may further include directly mechanically controlling the volume of the container. The container may include a piston chamber in which a piston is disposed, the position of the piston defining the volume of a cavity, and the direct mechanical control The step of moving the exhaled breath includes actuating the piston. The method may further include moving the exhaled breath into the piston chamber through a valve disposed between the breath input interface and the container. The method may include controlling the valve to close and controlling actuation of the piston to propel the exhaled breath in the cavity through at least one sorbent tube connected to the container.

[0063] The container may include an at least partially flexible, collapsible receptacle, and the method may further include propelling the exhaled breath into the at least partially flexible, collapsible receptacle at the volumetric rate of increase via a pump intermediate the breath input interface and the container.

[0064] The method may further include controlling the pump to propel the exhaled gas within the cavity through a subset of the at least one sorbent tube connected to the at least partially flexible collapsible receptacle. The method may include controlling movement of the exhaled gas into the piston chamber via a valve.

[0065] The method may further include controlling movement of the exhaled gas to the piston chamber via a valve. The method may further include measuring a component level in the exhaust conduit, comparing the component level with a component level target range via the at least one controller, comparing a rate of change of the component level with a component level rate target range, and controlling to open the valve based at least in part on whether the component level is within the component level target range and whether the rate of change is within the component level rate target range. The component level may be a carbon dioxide level, the component level target range may be a carbon dioxide level target range, and the component level rate target range may be a carbon dioxide level rate target range.

[0066] An inlet conduit of a first conduit system may extend from the inlet interface toward the container, and the method may further include measuring the flow rate of the exhaled breath along the inlet conduit via a flow meter. The rate of volumetric increase of the volume of the container may be proportional to the flow rate. The method may further include directly mechanically controlling the volume of the container with the at least one controller. The container may include a piston chamber having an actuable piston disposed therein, and the method may further include actuating a position of the piston within the piston chamber to define the volume of a cavity. The method may further include controlling movement of the exhaled breath into the piston chamber via a valve. The method may further include controlling the valve to close and controlling actuation of the piston to propel the exhaled breath within the cavity through a subset of at least one sorbent tube connected to the container.

[0067] The container may include an at least partially flexible, collapsible receptacle, and the method may further include propelling the exhaled breath at the volumetric rate into the at least partially flexible, collapsible receptacle via a pump positioned intermediate the exhaled breath input interface and the container.

[0068] Other technical advantages will become readily apparent to one of ordinary skill in the art upon examination of the following figures and description.

[0069] For a better understanding of the embodiment(s) described herein, and for purposes of illustration only, the embodiments ( To show more clearly how the invention may be carried out, reference will now be made, by way of example only, to the accompanying drawings in which: [Brief explanation of the drawings]

[0070] [Figure 1] FIG. 1 illustrates a breath sampling device according to one embodiment thereof. [Figure 2]FIG. 2 is a schematic diagram showing a sorbent tube for use with the device of FIG. 1. [Figure 3] 2 is a flow chart of a general method for collecting exhaled breath using the device of FIG. 1. [Figure 4A] 2 shows the breath sampler of FIG. 1 with ambient air being drawn into the piston chamber. [Figure 4B] FIG. 4B shows the breath sample collection device of FIG. 4A while flushing the device with ambient air. [Figure 4C] FIG. 4B shows a sorbent tube being installed in the breath sampler of FIG. 4A and ambient air being drawn into the container. [Figure 4D] FIG. 4B shows ambient air being forced through one of the sorbent tubes in the breath sampler of FIG. 4A. [Figure 4E] 4B illustrates the breath sampler of FIG. 4A as the person begins blowing into the breath sampler. [Figure 4F] FIG. 4D illustrates the breath sampler of FIG. 4C collecting a breath sample after the breath is determined to be alveolar breath. [Figure 4G] FIG. 4D illustrates the use of the breath sampler of FIG. 4C to prime the breath sampler. [Figure 4H] FIG. 4D shows the breath sampling device of FIG. 4C after the sorbent tube has been loaded and a breath sample is being collected. [Figure 4I] FIG. 4D shows the breath sampling device of FIG. 4C flowing a collected breath sample through one of the sorbent tubes. [Figure 5] 1 is a graph showing carbon dioxide levels in exhaled breath over time. [Figure 6] FIG. 10 shows the humidity level in the breath sampler while the humidity is being removed by the pump. [Figure 7A] FIG. 1 illustrates a breath sample collection device including a folded bag and its operating environment according to another embodiment. [Figure 7B] FIG. 7B shows the device of FIG. 7A with the bladder inflated. [Figure 8] FIG. 10 shows a breath sampling device according to a further embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0071] Unless otherwise noted, items depicted in the drawings are not necessarily drawn to scale.

[0072] For simplicity and clarity of illustration, reference numerals may be repeated among the figures where considered appropriate to indicate corresponding or similar elements. Furthermore, numerous specific details are set forth to provide a thorough understanding of one or more embodiments described herein. However, those skilled in the art will understand that the embodiments described herein may be practiced without these specific details. In other instances, well-known methods, procedures, and components have not been described in detail so as not to obscure the embodiments described herein. While exemplary embodiments are shown in the figures and described below, it should be understood at the outset that the principles of the present disclosure can be implemented using any number of techniques, whether currently known or not. The present disclosure should in no way be limited to the exemplary embodiments and techniques illustrated in the figures and described below.

[0073] As used throughout this specification, various terms may be read as follows, unless the context indicates otherwise: "or" as used throughout is inclusive as if written "and / or" and singular articles and pronouns as used throughout Terms include their plurals and vice versa, and likewise, gender pronouns include their corresponding pronouns, so that pronouns should not be understood as limiting anything described herein to use, implementation, performance, etc., by a single gender, and "exemplary" should be understood as "illustrative" or "exemplifying," and not necessarily as "preferred" over other embodiments. Further definitions of terms may be set forth herein, and these may apply to preceding and following instances of those terms as understood from reading this specification.

[0074] Modifications, additions, or omissions may be made to the systems, devices, and methods described herein without departing from the scope of the present disclosure. For example, system and device components may be integrated or separated. Furthermore, the operations of the systems and devices disclosed herein may be performed by more, fewer, or other components, and the methods described may include more, fewer, or other steps. Furthermore, steps may be performed in any suitable order. As used herein, "each" refers to each member of a set or each member of a subset of a set.

[0075] Any module, unit, component, server, computer, terminal, engine, or device illustrated herein that executes instructions may include or access computer-readable media, such as storage media, computer storage media, or data storage devices (removable and / or non-removable), for example, magnetic disks, optical disks, or tape. Computer storage media may include volatile and non-volatile, removable and non-removable media implemented in any method or technology for storage of information, such as computer-readable instructions, data structures, program modules, or other data. Examples of computer storage media include RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store desired information and that can be accessed by an application, module, or both. Any such computer storage media may be part of, accessible to, or connectable to a device. Furthermore, unless the context clearly indicates otherwise, any processor or controller defined herein may be implemented as a single processor or as multiple processors. Multiple processors may be collocated or distributed, and although a single processor is illustrated, any processing function referred to herein may be performed by one or multiple processors. Any method, application, or module described herein may be implemented using computer-readable / executable instructions stored or otherwise maintained by such computer-readable media and executable by one or more processors.

[0076] FIG. 1 illustrates an embodiment of a breath sampler 20. The breath sampler 20 allows for collection of breath samples in sorbent tubes asynchronously with the time when exhaled breath is provided. The breath sampler 20 includes a container for receiving the exhaled breath. The exhaled breath is then flowed through one or more sorbent tubes asynchronously with the time when the exhaled breath is received. Flowing the exhaled breath through one or more sorbent tubes can be performed by generating a positive relative pressure difference to propel the exhaled breath, by generating a negative relative pressure difference to draw the exhaled breath, or by any other suitable method. As a result, adsorption of the exhaled breath by the sorbent tubes can be more precisely controlled.

[0077] The breath sampler 20 includes a breath input interface for receiving exhaled breath from a person. The breath input interface 24 includes a mouthpiece 36 that is secured to the breath inlet end 40 of a breath inlet conduit 44 of a pre-collection conduit system 46.

[0078] The mouthpiece 36 is preferably made of inexpensive polypropylene or other suitably safe material so as to be disposable / replaceable. More preferably, the mouthpiece 36 does not off-gas volatile organic compounds ("VOCs") or off-gass VOCs at a slow rate so as not to significantly contaminate the breath sample. The mouthpiece 36 may include a viral / bacterial filter to exclude bacteria and particulates from the sample. By making the mouthpiece 36 disposable, a new filter can be provided for each patient to avoid cross-contamination of the sample and the transmission of viruses, bacteria, etc.

[0079] The polypropylene of the mouthpiece 36 is clear and will cloud slightly in humid conditions, and as condensation within the breath sampler 20 may be undesirable, this feature can be used to visually detect condensation.

[0080] In other embodiments, the breath input interface may be configured to receive breath from other animals.

[0081] The conduit of the breath sampler 20 is made of stainless steel coated with an inert coating, which may be made of any suitably inert material, such as a silica-based or quartz material.

[0082] The exhaust conduit 48 is connected at its first end to and branches off from the inlet conduit 44. A set of metering devices, including a hygrometer 52 for measuring humidity within the exhaust conduit 48, is disposed along the exhaust conduit 48. Condensation can impair the function of the breath sampler 20 in that the condensation can trap components of a person's exhaled breath and thus cause them to be inaccurately represented in the collected breath sample. Furthermore, certain levels of humidity and / or condensation can affect the function of other components of the breath sampler 20. A capnometer 56 is disposed along the exhaust conduit 48 to measure the carbon dioxide content of the patient's exhaled breath. Similarly, a flow meter 60 is disposed along the exhaust conduit 48 to measure the flow rate of exhaled breath along the exhaust conduit 48. A low-pressure resistance section 64 along the exhaust conduit 48 provides a low amount of resistance to gas flow along the exhaust conduit 48 toward an exhaust conduit outlet 68 at the second end of the exhaust conduit 48. The low pressure resistance portion 64 acts as a cap on the exhaust conduit 48, inhibiting return diffusion gases from entering the exhaust conduit 48 while allowing gas to flow in both directions as needed. Any suitable structure may be used to provide the low pressure resistance portion 64, such as a flexible or hinged flap, a section of conduit having a restricted cross section or change in direction(s).

[0083] The air circulation system includes a pump conduit 76 that branches off from the exhaust conduit 48 and terminates in a motor-driven pump 72. The pump 72 is configured to draw ambient air through the exhaust conduit 48 and the inhalation conduit 44, as needed, such as through the mouthpiece 36, and expel it to the surrounding environment. Any fluid pump suitable for use with gases may be employed.

[0084] The inner diameter sizes of the mouthpiece 36 and conduit sections 44, 48 are selected to provide only minor resistance to the exhalation of breath through the mouthpiece 36. Additionally, the conduit sections 44, 48 can be heated or cooled, if desired, to control the formation of condensation therealong, which may be desirable to reduce the likelihood of condensation passing to a breath sampling device such as a sorbent tube.

[0085] The exhaled breath collection valve 80 is connected to the exhaled breath intake conduit 44 and is connected to the exhaled breath input jack of the exhaled breath intake conduit 44. The exhalation input interface 24 controls the flow of gas from the exhalation input interface 24 to the exhalation collection conduit 84 of the exhalation capture conduit system 82. The exhalation intake conduit 44 forms part of a direct path between the exhalation input interface 24 and the exhalation capture conduit system 82. The intake valve 88 controls the flow of gas into and out of the exhalation collection conduit 84 via an ambient air inlet 92. An air filter 96 is disposed between the ambient air inlet 92 and the intake valve 88 and filters the incoming ambient air to inhibit the ingress of particulate contamination therein.

[0086] The container is in fluid communication with the breath collection conduit 84 and is configured to store breath received from the breath collection conduit. The container in this embodiment includes a piston chamber 100 having a cavity 104 therein defined at least in part by the interior walls of the piston chamber 100. The piston chamber 100 has a volume of 2 liters and may have any suitable cross-sectional shape. A piston 108 corresponds in shape to the piston chamber 100, is disposed within the piston chamber 100, and is driven by a piston motor 112. The piston 108 seals against the sides of the piston chamber 100 to provide an airtight seal. The piston motor 112 may be any suitable type of motor for actuating the piston 108 within the piston chamber 100.

[0087] The volume of cavity 104 can be directly mechanically controlled by positioning piston 108 within piston chamber 100 by piston motor 112. Furthermore, the rate of volume change of cavity 104 can be controlled by actuating piston 108 within piston chamber 100 at a corresponding speed to either increase the volume of cavity 104 by moving further into piston chamber 100, thereby defining a rate of volume increase, or decrease the volume of cavity 104 by moving further out of piston chamber 100, thereby defining a rate of volume decrease.

[0088] In another embodiment, the piston chamber is configured to have an interior space and the piston has a similar cross-sectional shape for slidable movement through the interior space of the piston chamber.

[0089] The breath collection conduit 84 is connected to a tube manifold 116. The tube inlet manifold 116 branches into four tube inlet valves 120. A bypass conduit 124 branches off from the breath collection conduit 84 and has a bypass valve 128 disposed along the bypass conduit 124 to prevent or allow gas flow therethrough. An outlet valve 132 is disposed toward an outlet 136 to control gas flow through the outlet 136. A tube outlet manifold 140 is connected to the bypass conduit 124 and branches into four tube outlet valves 144. The tube inlet valve 120 and the tube outlet valve 144 have connectors for receiving sorbent tubes. In other embodiments, the breath sample collection device 20 can be configured to accept and use any number of sorbent tubes.

[0090] Controller 148 controls the operation of breath sampler 20. Controller 148 is connected to valves 80, 88, 120, 128, 132, and 144 and causes these valves to open and close as described below in this specification. In other embodiments, the functions of controller 148 may be performed by two or more controllers.

[0091] A display 150 is controlled by the controller 148 to provide instructions and information to the person, as well as measures taken by the breath sampler 20, such as the degree of completion of the procedure, an estimated amount of time remaining, etc.

[0092] The internal components that come into contact with the exhaled air are generally inert. The conduits and valves are made of stainless steel and have an inert coating. The sealing elements within the valves are made of FKM, a family of fluoroelastomer materials, or other suitable materials with very low off-gassing rates. The polypropylene mouthpiece 36 is made of a resilient material and may off-gas, but the level is within acceptable tolerance levels.

[0093] Referring now to FIG. 2, an exemplary sorbent tube 152 is shown. The sorbent tube 152 has a tubular stainless steel casing 156 defining openings 160 at each end. The receiving end 164 of the sorbent tube 152 receives the gaseous fluid to be adsorbed. In the exemplary described embodiment, the gaseous fluid is human exhaled breath collected from a human for testing. A foam separator 168 is positioned toward the receiving end and is configured to more evenly distribute fluid pressure across the cross-section of the stainless steel casing 156. An adsorbent material 172 is positioned adjacent to the foam separator 168 and another foam separator 110. The separator may alternatively be made of wire mesh or other suitable material. The adsorbent material 172 is highly porous and has a relatively high surface area, selected for sampling specific compounds to capture and retain the compound of interest even in the presence of other compounds. Furthermore, the adsorbent material 172 allows the collected compound to be easily desorbed or extracted for analysis. Furthermore, the selected solid adsorbent material does not react with the sample. In particular examples, the solid sorbent material is Tenax TA or a carbon material. When the gaseous fluid is received through receiving end 164, the sample becomes more concentrated toward receiving end 164 of sorbent tube 152. In other embodiments, the composition and configuration of the sorbent tube can vary, as will be understood by those skilled in the art.

[0094] A method 200 for collecting a breath sample using breath sample collection device 20 will now be described with reference to Figures 1, 3, and 4A-4G.

[0095] Method 200 begins by drawing ambient air into the system (210). The system flushes any stagnant residual air by drawing in ambient air and then expelling it through conduits 44, 48, 68, 76, 84, and 124. This is done to ensure there is no cross-contamination of the currently collected breath with breath from a previous person. Stagnant room air in the system is replaced with fresh room air during this flush.

[0096] First, it is confirmed that valves 80, 120, and 128 are closed. Next, controller 148 commands suction valve 88 to open and operates piston motor 112 to retract piston 108 within piston chamber 100. As piston 108 retracts within piston chamber 100, the volume of cavity 104 defined by the inner wall of piston chamber 100 and piston 108, which is hermetically sealed therein, increases. As a result, the pressure within cavity 104 drops rapidly. Ambient air is drawn into cavity 104 through ambient air inlet 96 and air filter 96.

[0097] 4A shows cavity 104 filled with drawn-in ambient air. For purposes of illustration, open valves include a stipple and closed valves lack a stipple. Air filter 96 removes particulates from the ambient air as it is being inhaled and before it enters breath collection conduit 84. During this inhalation of ambient air, breath collection valve 80 is closed, but traces of the previous person's breath may be present along breath inlet conduit 44 and along exhaust conduit 48. It is desirable to keep breath collection valve 80 closed so that only ambient air is drawn in and filtered through air filter 96.

[0098] As ambient air is drawn into piston chamber 100, it is used to flush the system (208). The controller closes intake valve 88 as piston 108 retracts within piston chamber 100, then opens all other valves. Once valves 80, 120, 128, 132, and 144 are open, controller 148 controls the piston motor. The controller 112 is directed to drive the piston 108 into the piston chamber 100, forcing the ambient air therein to exit the mouthpiece 36 through the inhalation conduit 44, through the exhaust conduit 48 and out the exhaust conduit outlet 68, through the exhalation collection conduit 84 and tube inlet manifold 116 and out the tube inlet valve 120, and through the bypass conduit 124 and tube outlet manifold 140 and out the outlet 136 and tube outlet valve 144. As a result, the conduits of the system are effectively filled with ambient air.

[0099] FIG. 4B illustrates flushing of the breath sampler 20.

[0100] After the system has been flushed with ambient air, valves 80, 120, 132, and 144 are closed again.

[0101] Once flushing is complete, the controller 148 determines whether to repeat the flushing (212). Flushing is repeated 5-10 times with approximately 10-20 liters of air to reduce the chance of the previous person's breath contaminating the breath sample being collected. If it is determined that the required number of flushes has not yet been completed, the controller 148 again begins the process of drawing in ambient air at 204.

[0102] Alternatively, if sufficient flushing is determined to have occurred, one or more sorbent tubes 152a-152d (or collectively referred to hereinafter as sorbent tubes 152) are loaded (213) into the breath sampler 20. The bypass valve 128 and the outlet valve 132 are closed. One to four sorbent tubes 152 are then loaded into the breath sampler 20.

[0103] In this embodiment, a sample of ambient air is used as a control against which the breath sample can be compared. The ambient air that a person inhales while providing a breath sample may contain several compounds that are quantified during analysis of the breath sample. To identify these compounds in the ambient air of the space in which the breath sampler 20 is located, the ambient air can be adsorbed onto one or more sorbent tubes 152. The breath sampler 20 collects ambient air in a manner somewhat similar to the collection of exhaled breath. Thus, at least two sorbent tubes 152 are loaded so that at least one can capture ambient air and at least one can capture exhaled breath.

[0104] Once the sorbent tube is loaded, ambient air is drawn 214 into the piston chamber 100, as shown in Figure 4C. The piston motor 112 is controlled to operate the piston 108, drawing in ambient air from the room in which the breath sampler 20 is located. As the piston 108 retracts within the piston chamber 100, the cavity 104 increases in size, and ambient air is drawn into the cavity 104 via the inlet 92, through the air filter 96, and the inlet valve 88.

[0105] As ambient air is drawn into the piston chamber 100, it is forced to flow (215) through a subset of the sorbent tubes 152, as shown in FIG. 4D . The controller 148 opens a first one of the tube inlet valves 120, a first one of the tube outlet valves 144, and the outlet valve 132. The controller 148 then directs the piston motor 112 to actuate the piston 108, moving it into the piston chamber 100 and decreasing the volume of the cavity 104. As the cavity volume decreases, the ambient air within the cavity 104 is forced through the first sorbent tube 152a and out through the outlet 136. The rate at which the ambient air is flowed through the sorbent tubes 152a is selected to provide time-efficient yet effective adsorption.

[0106] If it is determined that the target volume of ambient air to be flowed through the sorbent tube 152a to capture the ambient air sample exceeds the capacity of the piston chamber (approximately 2 liters), steps 214 and 215 are repeated as necessary until the ambient air sample is captured in the sorbent tube 152a.

[0107] Next, the person 180 from whom the breath sample is to be collected is instructed via the display 150 to exhale into the mouthpiece 36 during a process called "pre-breath" (216), as shown in FIG. 4E. "Pre-breath" is used to familiarize the person 180 with exhaling into the breath sampler 20 in a predetermined manner, according to criteria established for the operation of the breath sampler 20. The display 150 provides instructions to the person 180 regarding a target exhaled volume of 20 liters per minute. By familiarizing the person 180 with how to exhale into the breath sampler 20, the person 180 typically becomes more consistent with their breath. A person typically becomes much better at controlling their exhaled volume after just one practice breath. Additionally, the exhaled breath provided during the pre-breath phase is used to prime the system's conduits.

[0108] When the breath collection valve 80 is closed, breath exhaled by the person 180 travels through the breath intake conduit 44 and along the exhaust conduit 48 .

[0109] During the pre-breath phase, capnometer 56 samples the air to measure the level of carbon dioxide therein. Because capnometer 56 samples the air frequently, capnometer 56 can also measure the rate of change of the carbon dioxide level. Flow meter 60 measures the flow rate of the exhaled air. Low-pressure resistor 64 provides a very low flow restriction for exhalation by person 180, and the exhaled air exits through exhaust conduit outlet 68.

[0110] Controller 148 constantly monitors signals from capnometer 56 and flow meter 60 to determine whether a set of breath collection criteria are met. These breath collection criteria are: (a) the carbon dioxide level reported by capnometer 56 is within a target range defined by a minimum threshold and an infinite upper limit; (b) the rate of change of the carbon dioxide level is within a target rate of change range defined by an infinite lower limit and a maximum rate of change threshold; and (c) the flow rate of the exhaled breath is within a target range defined by a minimum flow rate threshold and a maximum flow rate threshold. In this embodiment, the minimum flow rate threshold is 20 liters / minute, and the maximum flow rate threshold is 25 liters / minute. Having the exhaled breath flow rate within the target range provides consistency to the breath provided by person 180. As will be appreciated, the target range is said to be defined by a threshold at one boundary of the target range, since the other boundary may logically be satisfied by an infinite or zero boundary, etc.

[0111] The first portion of person 180's exhaled breath includes air from the mouth and / or throat where oxygen / carbon dioxide exchange in the lungs did not occur, thereby providing a higher percentage of oxygen. As person 180 continues to exhale, a larger portion of the exhaled breath comes from the lungs where oxygen / carbon dioxide exchange does occur. As a result, carbon dioxide released from the bloodstream becomes a larger, concomitant portion of the exhaled breath (approximately 3-7%). The carbon dioxide level then reaches a knee where the rate of change of carbon dioxide decreases rapidly. This indicates that the exhaled breath is coming from within the lungs, rather than from the mouth or trachea. Such exhaled breath is called alveolar exhalation. In this embodiment, the target range for carbon dioxide levels is 3% of the exhaled breath to an infinity upper limit, and the target rate of change for carbon dioxide levels is 0% to 2% of the exhaled breath per second.

[0112] FIG. 5 shows the carbon dioxide level over time in the exhaled breath relative to the threshold Ω. The rate of change in carbon dioxide level increases generally consistently until alveolar expiration, at which point carbon dioxide The rate of change of carbon dioxide levels drops significantly, reflected as the knee K. After this, the carbon dioxide levels in exhaled breath stabilize.

[0113] In this configuration, the criteria for exhaled breath collection are: the carbon dioxide level is above a threshold of 2%; this level is well above atmospheric levels but below levels expected to be seen in humans (e.g., a minimum of 3% from individuals with reduced lung function); the rate of change of carbon dioxide levels is below a predetermined threshold; and the exhaled breath flow rate is above 20 liters per minute.

[0114] These three criteria will often prevent breath sampling from being triggered under less than ideal circumstances.

[0115] Once all three criteria are met, breath collection begins (224), as shown in FIG. 4F. Once the three criteria are met, the controller 148 opens the breath collection valve 80 and directs the piston motor 112 to drive the piston 108 to increase the volume of the cavity 104 as it receives exhaled breath. The piston 108 is controlled to operate at a speed that depends on the flow rate reported by the flow meter 60 to provide a rate of volume increase for the cavity 104. In this particular embodiment, the rate of volume increase for the cavity 104 achieved as a result of operating the piston 108 is proportional to the flow rate detected by the flow meter 60 along the exhaust conduit 48. In other embodiments, the rate of volume change for the cavity 104 may be varied in different manners as a function of the flow rate reported by the flow meter 60.

[0116] As the volume of cavity 104 increases, it becomes easier for person 180 to exhale due to the resulting pressure differential. If person 180 is exhaling at 20 liters per minute, person 180 is only exhaling with the force required to exhale 4 liters per minute, because 16 liters per minute are being drawn out by the pressure differential in the system as a result of the increased volume of cavity 104. This can allow individuals with a reduced ability to exhale forcefully, such as may be the case with lung cancer and respiratory diseases, to provide breath samples.

[0117] As previously indicated, the flow meter 60 is positioned along the normal downstream path for airflow to prevent contamination of the currently collected breath sample with breath from a previous breath sample donor that has adhered to the flow meter 60. If the actuation speed of the piston 108, and therefore the rate at which the cavity volume increases, were fixed, some breath would be expelled through the flow meter 60 as the person 180 exhaled faster. This could cause problems if more exhaled breath escapes along the exhaust conduit 48 than desired, causing the flow rate to be lower than the rate at which the volume of the cavity 104 increases.

[0118] In this configuration, controller 148 controls piston 108 to increase the volume of cavity 104 at a rate that depends on the flow rate measured by flow meter 60. In particular, the volume of cavity 104 is increased by four times the flow rate measured by flow meter 60. That is, the increase in volume of cavity 104 captures 80% of the exhaled air received from person 180.

[0119] The hygrometer 52, capnometer 56, and flow meter 60 are all positioned along the exhaust conduit 48 away from the inlet conduit 44. These metering devices are capable of off-gassing VOCs. Additionally, these metering devices can become contaminated by the exhaled breath of individuals who have previously sampled their breath. By positioning these metering devices along the exhaust conduit 48, along which the exhaled breath flows away from the direct path along the inlet conduit 44, contamination by other exhaled or off-gassed VOCs is inhibited. Additionally, these metering devices and conduits are provided with an inert interior coating to reduce the probability of exhaled or off-gassed VOCs adhering to their interior surfaces, thereby reducing the likelihood of exhaled or off-gassed VOCs adhering to previously received exhaled breath and off-gassed VOCs. This further reduces the probability of contamination of the breath sample by

[0120] By moving a portion of the received exhaled air down the exhaust conduit 48, along which the hygrometer 52, capnometer 56, and flow meter 60 are positioned, the overall, generally unrestricted exhaled air volume can be measured. This exhaled air volume is equal to the flow rate measured by the flow meter 60 plus the rate of volume increase of the cavity 104, measured based on the rate of actuation of the position of the piston 108. This exhaled air volume can then be used to determine how quickly the volume of the cavity 104 should increase. By keeping the rate of increase of the volume of the cavity 104 less than the measured exhaled air volume, a portion of the exhaled air always moves down the exhaust conduit 48, allowing for continuous monitoring of the overall exhaled air volume.

[0121] This ratio of 80% of the total exhaled volume was selected to provide a generous reaction time buffer so that if the person's exhaled volume were to rapidly decrease, the exhaled volume would be unlikely to be exceeded and the rate of volume increase of cavity 104 could be adjusted with a small lag. If the rate of volume increase of cavity 104 exceeds the person's exhaled volume, the pressure difference within the system could unnaturally draw exhaled air from the person, which could be an undesirable result, and could draw ambient air through exhaust conduit outlet 68.

[0122] Information regarding the total rate of exhalation may be presented to the person 180 on the display 150 to encourage the person 180 to exhalate within a target range or at least at a threshold rate.

[0123] When the person 180 increases the exhalation rate up to the threshold of 25 liters / minute, the piston 108 is actuated by the controller to move to increase the volume of the cavity 104 so that 80% of the exhaled air is collected within the cavity 104.

[0124] If the person 180 decreases the exhalation volume, the piston speed is adjusted so that the volume change in cavity 104 is always less than the exhalation volume, ensuring that no air is drawn through the flow meter route and that the exhaled flow rate can be metered through the flow meter 60.

[0125] When the flow rate detected by the flow meter 60 enters the end flow rate range, the movement of the piston 108 is stopped and collection of exhaled air in the piston chamber 100 is stopped. The end flow rate range in this embodiment is from an infinite lower limit to 2 liters of exhaled air per minute.

[0126] The person 180 may not have enough exhaled air to fill the entire piston chamber 100. Therefore, when the flow meter 60 reports that the exhaled volume has dropped below a certain value, the movement of the piston 108, and therefore the collection of exhaled air, is stopped.

[0127] Next, the controller 148 determines whether the target volume for priming the system has been collected (228). The breath sampler 20 collects one liter of breath to prime the system. If less than the target volume of one liter of breath has been collected, the controller 147 controls the breath sampler 20 to perform a pre-breath collection at 216.

[0128] Alternatively, if it is determined at 228 that sufficient exhaled air has been collected to prime the system, the collected exhaled air is used to prime the system (232), as shown in FIGURE 4G. The controller 184 directs the exhaled air collection valve 80 to close and the bypass valve 128 and the outlet valve 132 to open. Additionally, the piston motor 112 directs the piston 108 to drive the piston 108 into the piston chamber 100, thereby decreasing the volume of the cavity 104. As the volume of the cavity 104 decreases (i.e., the volume decrease rate), the exhaled air contained in the cavity 104 decreases. The air is propelled through the air collection conduit 84, the tubing inlet manifold 116, the tubing outlet manifold 140, the bypass conduit 124, and the outlet 136, thereby priming these conduits with the collected exhaled air of the person 180.

[0129] Once the capture conduit system 82 has been primed, exhaled breaths are again sampled using the same general approach from 216 to 228. That is, a pre-breath is again performed (240). During the pre-breath, the controller 148 determines whether exhalation criteria are met (244). If so, exhaled breaths are sampled (248), as shown in FIG. 4H.

[0130] It is then determined whether the target volume of exhaled breath for adsorption has been collected or whether the piston chamber 100 is full (252). If the target volume of exhaled breath for adsorption into the sorbent tube(s) 152 has not yet been collected, and if the piston chamber 100 is not full, additional exhaled breaths are again collected, starting with the pre-exhaled breath collection at 240. Person 180 is instructed to take another breath.

[0131] Alternatively, if it is determined at 252 that the target volume of exhaled breath has been collected or that the piston chamber 100 is full, the exhaled breath is flowed through a second subset of the sorbent tubes 152 (256). FIG. 4I illustrates the piston chamber 100 being filled with exhaled breath. The controller 148 is configured to control the flow of at least a portion of the exhaled breath from the container to the subset of sorbent tubes 152 asynchronously with the receipt of the exhaled breath. That is, the flow of exhaled breath from the container to the subset of sorbent tubes 152 can be performed independently of the timing of receipt of the exhaled breath, apart from having to occur after receipt of the exhaled breath. The second subset can be any number of sorbent tubes 152 connected to the breath sampler 20 that are not sorbing ambient air. After priming the conduits, once the machine has collected a full piston chamber's worth of exhaled air, the controller 148 closes the exhaled air collection valve 80 and controls each of the tube inlet valves 120 to either leave them in their previously closed or open states, or to open or close each of the tube inlet valves 120 to select a subset of the sorbent tubes 152 through which at least a portion of the exhaled air will flow. In this embodiment, the controller 148 opens the corresponding one of the tube inlet valves 120 and tube outlet valves 144, as well as the outlet valve 132, for the sorbent tube 152 through which the sample will be adsorbed. The piston 108 is controlled by the controller 148 to slowly move the exhaled air therethrough at a predetermined velocity that pushes the exhaled air through the selected sorbent tube 152.

[0132] As the exhaled breath is flowed through the second subset of sorbent tubes 152, air is simultaneously flowed (260) through the pre-collection conduit system 46 to reduce condensation therein. Specifically, the controller 148 controls the pump 72 to turn on and draw ambient air from the mouthpiece 36 and exhaust conduit outlet 68 through the exhaust conduit 48 to help mitigate condensation from the line. Because metering devices do not function optimally in very humid conditions, the pump 72 acts to reduce condensation / humidity within the exhaust conduit 48. As the pump 72 operates, the humidity level is monitored via the hygrometer 52.

[0133] FIG. 6 shows a typical graph of humidity levels detected by the hygrometer 52 over time. Before the pump 72 is turned on at t1, the humidity is at a first level h1. A high level of condensation can be observed on the transparent mouthpiece 36. After the pump 72 is turned on, the humidity decreases over time, so the rate of change of humidity is negative. When the rate of change of the humidity level is within the target rate of change range at time t2, the controller 148 determines that there is relatively little condensation in the pre-collection conduit system 46 and therefore relatively little value in continuing to operate the pump 72, and therefore stops the pump 72. 2. This humidity level change rate target range is, in this embodiment, -0.05% relative humidity per second to 0% relative humidity per second, but can be varied in other scenarios. In this way, breath sampler 20 can undergo maintenance during an otherwise idle time. In other embodiments, this condensation reduction step can be performed through the use of a secondary external hygrometer based on the humidity level being outside of the humidity level target range of zero to the humidity level of the ambient air.

[0134] The rate at which the breath flows through the sorbent tube 152 is 500 milliliters per minute. The leak capacity of the sorbent tube 152 has been found to be affected by the sorbent flow rate. The leak capacity is the volume at which half of the sample is captured in the sorbent tube 152 and the other half flows out the other side of the sorbent tube 152. At the leak capacity, the sorbent in the sorbent tube 152 is at a point where enough surface area is utilized to allow molecules to pass through as easily as they are captured. Increasing the flow rate of breath through the sorbent tube 152 decreases the leak capacity. This biases the captured sample toward heavier molecules and fewer smaller molecules. By controlling the flow rate of breath through the sorbent tube 152, the adsorption rate for specific molecules can be controlled.

[0135] It is then determined (264) whether the target volume has been flushed through the subset of sorbent tubes 152. If the desired amount of breath has not yet been flushed through the subset of sorbent tubes 152, the method 200 returns to 240 where more breath is collected to be flushed through the subset of sorbent tubes 152.

[0136] Upon determining that the target volume has been flowed through the currently selected sorbent tube 152, the controller 148 can terminate flow of exhaled air through the sorbent tube 152 via the tube inlet and outlet valves 120, 144 and begin flowing exhaled air through another one of the sorbent tubes 152.

[0137] The breath sampler 20 can be configured to select different sized subsets of sorbent tubes for the ambient air and exhaled breath samples. In a preferred embodiment, two sorbent tubes of ambient air sample and two sorbent tubes of exhaled breath sample are collected. In other embodiments, ambient air may not be collected.

[0138] Although not explicitly shown, it will be understood that the controller 148 is connected to each of the valves, the hygrometer 52, the capnometer 56, the flow meter 60, the pump 72, the piston motor 112, and other components of the breath sampling device 20.

[0139] In other embodiments, the container having a controllable volume may be any other structure for providing a cavity having a controllable volume. For example, in one particular embodiment, the container may include a bellows-like structure.

[0140] 7A illustrates another embodiment of a breath sampler 300. The breath sampler 300 is similar to the breath sampler 20 of FIGS. 1 and 4A-4I, except that the breath sampler 300 employs a bidirectional pump 304 and a container including an at least partially flexible, collapsible receptacle 308 in place of the piston chamber 100 and piston 108. The at least partially flexible, collapsible receptacle 308 is secured to the bidirectional pump 304, which in turn is secured to the breath collection conduit 84.

[0141] In this embodiment, the at least partially flexible collapsible receptacle 308 is a bag made from polyvinyl fluoride, a very flexible material with high tensile properties. While polyvinyl fluoride is not impermeable, this is preferred as it does not significantly affect its performance in this application. It has suitably low permeability. Furthermore, polyvinyl fluoride is relatively inert. Other suitably flexible, relatively non-porous, relatively inert materials may additionally or alternatively be used in other embodiments. Furthermore, the receptacle may also include a non-flexible portion.

[0142] The at least partially flexible collapsible receptacle 308 has an internal cavity with a volume defined by the amount of fluid therein. In Figure 7A, the at least partially flexible collapsible receptacle 308 is shown to have substantially no exhaled or ambient air therein, and therefore the cavity has substantially no volume. In this collapsed state, the at least partially flexible collapsible receptacle 308 can be compressed to facilitate packaging.

[0143] The bidirectional pump 304 has a controllable flow rate and provides bidirectional flow of exhaled gas and / or ambient air. The bidirectional pump 304 is controllable by the controller 148 to draw exhaled gas and / or ambient air from the exhaled gas collection conduit system 82 into the at least partially flexible collapsible receptacle 308, and to draw exhaled gas and / or ambient air from the at least partially flexible collapsible receptacle 308 into the exhaled gas collection conduit system 82. Thus, the controller 148 can control the bidirectional pump 304, and thereby the at least partially flexible collapsible receptacle 308, to provide the same general functionality as the piston chamber 100, piston motor 112, and piston 108. That is, the controller 148 can control the volume of the at least partially flexible collapsible receptacle 308 through operation of the pump.

[0144] FIG. 7B shows the at least partially flexible collapsible receptacle 308 after the two-way pump 304 has drawn exhaled air and / or ambient air therein, thus expanding the cavity of the at least partially flexible collapsible receptacle 308 and the at least partially flexible collapsible receptacle 308 itself.

[0145] The breath sample collection device 300 also differs in that, instead of a display, it has an array of optical elements in the form of LEDs 312 and an audio speaker 316. Flow rate notifications can be presented to the user via the LEDs 312. For example, the array of LEDs 312 can include a red LED, a yellow LED, a green LED, a yellow LED, and a sequence of red LEDs. If the flow rate of breath through the breath input interface 24 is too low, a corresponding red or yellow LED can be illuminated. If the flow rate of breath through the breath input interface 24 is satisfactory, a green LED can be illuminated. Similarly, if the flow rate of breath through the breath input interface 24 is too high, a second corresponding red or yellow LED can be illuminated. In this way, a person can be visually indicated how their breath flow rate compares to a target flow rate. In other embodiments, other types of optical elements can be employed.

[0146] The audio speaker 316 can be used in a similar manner, with flow rate notifications being provided by clicks at different frequencies, sounds at different frequencies, different tones, etc.

[0147] 8 illustrates a breath sampling device 400 according to a further embodiment. In this embodiment, the flow meter 60 is positioned along the breath intake conduit 44. The flow meter 60 therefore measures the total exhaled breath volume along the breath intake conduit 44. During breath sampling, the controller 148 can control the piston motor 112 to operate the piston 108 so that the volumetric change rate of the cavity 104 is set to a percentage of the flow rate measured by the flow meter 60. In a preferred embodiment, the volumetric change rate of the cavity 104 is set to 80% of the flow rate measured by the flow meter 60 during breath sampling. Excess exhaled air flows along the exhaust conduit 48 and exits through the exhaust conduit outlet 68.

[0148] While the above-described embodiment employs a capnometer to measure the level of carbon dioxide in the exhaled breath, other embodiments may employ other types of metering devices to measure the levels of other constituents in the exhaled breath, such as those that can indicate when alveolar exhalation is being detected. These metering devices can determine when alveolar exhalation is being detected by detecting the levels of these other constituents and the rate of change of these levels. For example, a metering device may measure the oxygen level in the exhaled breath and determine that alveolar exhalation is currently being detected when it detects that the change in oxygen level falls within a target rate of change range having a maximum rate of change threshold.

[0149] In other embodiments, other types of breath sample reservoirs may be employed aside from sorbent tubes. For example, solid phase microextraction ("SPME") fibers may alternatively be used to reservoir the breath sample. Another example is silica gel. Yet another example is a chemical reaction that results in a visual indication (e.g., Drierite turns purple in the presence of moisture) or a powder that produces by-product chemicals that can be more easily analyzed later. Other types of breath sample reservoirs will occur to those skilled in the art.

[0150] The volume of the reservoir may be mechanically controlled in other ways. In one particular embodiment, the reservoir may include a bellows that can be actuated to expand and contract.

[0151] Although certain advantages have been enumerated above, various embodiments may include some, none, or all of the enumerated advantages.

[0152] Those skilled in the art will recognize that many more alternative implementations and modifications are possible, and that the above examples are merely illustrative of one or more implementations, the scope of which is therefore intended to be limited only by the claims appended hereto. [Explanation of symbols]

[0153] 20 Breath sample collection device 24 Breath Input Interface 36 Mouthpiece 40 Exhalation and Inhalation End 44 Exhalation and Inhalation Conduit 46 Pre-collection conduit system 48 Exhaust duct 52 Hygrometer 56 Capnometer 60 flow meter 64 Low-voltage resistor 68 Exhaust duct outlet 72 Pump 76 Pump conduit 80 Breath collection valve 82 Capture conduit system 84 Breath collection tube 88 Suction valve 92 Ambient Air Inlet 96 Air Filter 100 piston chamber 104 Cavity 108 Piston 112 Piston motor 116 Tube Inlet Manifold 120 Tube Inlet Valve 124 Bypass conduit 128 Bypass valve 132 Outlet Valve 136 Outlet 140 Tube Outlet Manifold 144 Tube Outlet Valve 148 Controller 150 displays 152 Adsorbent tube 156 Stainless Steel Casing 160 opening 164 Receiving end 168 Foam separator 172 Adsorbent 176 Foam separator 180 people 200 ways 204 Drawing in ambient air 208 Flushing device 212 Repeat flushing? 213 Loading the sorbent tube 214 Drawing in ambient air 215 Flow air through a first subset of the adsorbent tubes. 216 Pre-exhaled breath collection 220 Did you meet the expiratory breath criteria? 224 Collecting breath to prime the system 228 Target volume? 232 Priming the system with collected breath 236 Loading the sorbent tube 240 Pre-exhaled breath sampling 244 Exhalation criteria met 248 Collecting breath 252 Target volume or container full? 256 Flow exhaled air through the sorbent tube(s) 260 Air is passed through a pre-sampling duct system to reduce condensation 264 Target volume? 300 Breath sample collection device 304 Two-way pump 308 Flexible Foldable Receptacle 312 LED 316 speakers

Claims

1. A breath sample collection device comprising: a breath input interface configured to receive exhaled breath; a container connected to the breath input interface for receiving at least a portion of the exhaled breath, the container having a cavity with a controllable volume; an inlet / outlet conduit of a first conduit system extending between the outlet / inlet interface and the container; an exhaust conduit of a first conduit system branching at a first end from the inhalation conduit and having an exhaust conduit outlet at a second end; a hygrometer disposed between the breath input interface and the exhaust conduit outlet for measuring a humidity level; a pump disposed between the expiratory breath input interface and the exhaust conduit outlet, the pump drawing air through the expiratory breath input interface and expelling air through the exhaust conduit outlet; an apparatus comprising: the expiratory breath input interface; and at least one controller configured to operate the pump based on the humidity level measured by the hygrometer to reduce humidity from the expiratory breath inlet conduit to the exhaust conduit, and configured to terminate operation of the pump when a rate of change of the humidity level is within a target rate of change range.

2. The apparatus of claim 1 , further comprising a flow meter positioned to measure flow along the exhaust conduit.

3. The device described in claim 2, wherein the controller is further configured to control the volume of the cavity to increase at a volumetric increase rate at most equal to the flow rate of the exhaled breath received by the breath input interface, and the volumetric increase rate of the volume of the container is proportional to the flow rate along the exhaust conduit.

4. The apparatus of claim 3 , wherein the volume of the container is directly mechanically controllable by the at least one controller.

5. 5. The apparatus of claim 4, wherein the container comprises a piston chamber having an actuatable piston disposed therein, the position of the piston within the piston chamber defining the volume of the cavity.

6. 6. The device of claim 5, further comprising a valve positioned to control the movement of the exhaled air into the piston chamber.

7. 7. The device of claim 6, further comprising at least one sorbent tube connected to the container, wherein the at least one controller is configured to control the valve to close and to control actuation of the piston to propel the exhaled air in the cavity through the at least one sorbent tube.

8. 4. The device of claim 3, wherein the container includes an at least partially flexible, collapsible receptacle, and the device further includes a bidirectional pump configured intermediate the exhaled breath input interface and the container to propel the exhaled breath into the at least partially flexible, collapsible receptacle at the volumetric rate of increase.

9. 9. The device of claim 8, further comprising at least one sorbent tube connected to the at least partially flexible collapsible receptacle, wherein the at least one controller is configured to control the pump to propel the exhaled air within the cavity through a subset of the at least one sorbent tube.

10. 10. The device of claim 9, further comprising a valve positioned to control movement of the exhaled gas into the at least partially flexible collapsible receptacle.

11. 11. The apparatus of claim 10, further comprising a metering device positioned to measure a constituent level in the exhaust conduit, wherein the at least one controller is configured to determine whether the constituent level is within a constituent level target range, determine whether the rate of change of the constituent level is within a constituent level rate target range, and control the valve to open based at least in part on whether the constituent level is within the constituent level target range and whether the rate of change is within the constituent level rate target range.

12. 12. The apparatus of claim 11, wherein the metering device is a capnometer, the constituent level is a carbon dioxide level, the constituent level target range is a carbon dioxide level target range, and the constituent level rate of change target range is a carbon dioxide level rate of change target range.

13. 7. The device of claim 6, further comprising at least one sorbent tube connected to the container, wherein the at least one controller is configured to control the valve to close and to control actuation of the piston to propel the exhaled air within the cavity through a subset of the at least one sorbent tube.

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