we refer firstly to fig1 a to 1 c . a preferred embodiment of a breath monitoring device 2 of the invention comprises a housing 4 in which is housed a means to record a first breathing state of a user , in the form of a combined exhalation speed and volume monitor ( not shown ), a data storage means in the form of a memory chip consisting of ram or eprom , and a means to detect a deviation from the first breathing state which comprises the means to record the first breathing state ( and to record subsequent breaths ) . thus the means to record a first breathing state of a user and means to detect a deviation from the first breathing state comprise one and the same means in this preferred embodiment . breath exhalation speed and volume monitors are well known , and any suitable monitor may be used such as a peak flow meter . the breath monitoring device also includes an indicator means in the form of a liquid crystal display panel 8 , set into the housing 4 , and operably connected to the recording means , deviation detection means and data storage means . extending from one end of the housing 4 , and also operably connected to the breath recordal means , data storage means and deviation detection means , is a fluid inlet 6 . a detachable mouthpiece 10 , as shown in fig1 a , can be connected to the fluid inlet 6 . the mouthpiece 10 includes a t - valve 12 , which allows exhaled breath to enter the fluid inlet 6 and into the device 2 , but allows air from outside of the device 2 to be inhaled through the t - valve when a user inhales . the distal end of the t - valve includes a flexible mask 14 arranged in use to be connected over the mouth of a user . use of the device 2 will now be described with reference to fig1 a to 1 c , and fig2 a to 2 c . a user firstly connects the detachable mouthpiece 10 to the fluid inlet 6 of the housing 4 of the device 2 . when it is desired to record a first breathing state of the user , the user places the facemask 14 over his or her mouth , and begins to breathe into the mouthpiece 10 . it is generally preferable to record a first breathing state in which the breathing state is unforced , that is the user breaths naturally into the mask 14 rather than forcing air into the mask and through the fluid inlet . the use of a mask 14 helps to produce unforced breathing by a user . if the mask 14 is not present , a user may tend to force exhalations into the fluid inlet 6 . as a user breaths into the mask 14 , exhaled breath enters the fluid inlet 6 through the t - valve 12 , and into the housing 4 of the device , where the desired parameters of the first breathing state are recorded , such as exhalation speed , and exhalation volume . when the user inhales , air is drawn through the t - valve from outside of the device 4 , and through the mask 14 into a user &# 39 ; s lungs and / or airways . the user may continue to breathe into the device 2 for a prescribed period of time , until a first breathing state is recorded . the first breathing state may be recorded from just one breath or a plurality of breaths over a user - defined or device - defined period of time . when the first breathing state has been recorded satisfactorily , the liquid crystal display panel 8 will indicate to the user that the breathing state has been recorded . in alternative embodiments the indicator means may be lights and / or warning sounds . [ 0052 ] fig2 a shows a graph of a recorded first breathing state of a user , in which the volume of exhaled air , and the duration of an exhaled breath have been monitored as the parameters of the first breathing state . in this example , the user exhaled for approximately 3 seconds per breath , with a flow of approximately 22 lpm ( litres per minute ). the recordal in this example was effected over a period of 30 seconds , such that a mean exhalation duration and flow could be recorded , and stored on the data storage means ( not shown ). once the first breathing state has been monitored and stored on the data storage means , the mouthpiece 10 may be optionally removed , as shown in fig1 b and 1c . when it is desired for the first user to have his or her breath monitored again , the user may place his or her mouth on the fluid inlet ( or mouthpiece 10 ), and breathe into the device 2 . as a first user exhales into the device , the means to detect deviation from the first breathing parameter will monitor the user &# 39 ; s breathing , and detect if any deviation from the first recorded breathing state has occurred . fig2 b shows a subsequent use of the device 2 by the first user of the recorded breathing state of fig2 a , in which the first breath , between 1 and 3 seconds , had been recorded and monitored by the deviation detection means , as corresponding within the parameters of the first breathing state of fig2 a ( in that the duration of exhalation and the flow were within acceptable deviation from the first breathing state recorded in fig2 a ). thus for the first exhaled breath , the liquid crystal display means 8 signals that the breath is within the first breathing state recorded on the data storage means and records an “ ok ” display , as shown in fig1 b . if a user forces breath into the device 2 into the fluid inlet 6 , as shown in the second breath on the graph of fig2 b , the deviation monitoring means will record that the exhalation has an increased duration , and , as shown in fig1 c will indicate on the liquid crystal display 8 that a breath falling outside of the first breathing state has occurred . [ 0054 ] fig2 c shows recordal of breaths from a second , different user to the first user of the device 2 . when the second user breathes into the device 2 , the duration of exhalation , as shown in fig2 c , is longer than the duration of exhalation of the first user , and the flow is substantially higher ( approximately 40 lpm ). the deviation detection means detects that a second user is using the device 2 , and displays an error message as shown in fig1 c . thus the device can be tailored to suit an individual , and prevent use of the device when a second user subsequently uses it . the device 2 may be used to monitor a first breathing state of a user when the user is at rest , or after physical exercise . the device 2 is particularly useful for when a user has undergone physical exercise , as there is a tendency for users to breathe into breath monitoring devices in a forced state , which does not accurately represent the volume , duration and gas content of the unforced breaths . the device 2 may form part of a direct or indirect calorimeter , which measures metabolism by monitoring oxygen or carbon dioxide volume in exhaled and inhaled gas . thus use of the device will prevent a user from forcing excess air into the calorimeter , thereby adversely affecting the results on metabolism study . in alternative embodiments of the breath monitoring device of the invention , there may be a means for the device to prevent a user from operating the device after a deviation from the first breathing state has been detected and / or indicated in subsequent breaths from a user . the operation prevention means may comprise a switch which , when the deviation detection means detects a deviation from the first breathing state , is triggered to prevent exhaled breath entering the device through the mouthpiece , for example . the device may also comprise means for a user to manually override the operation prevention means , such as a manual switch connected thereto , for example . there may also be a means on the device for a user to accept or decline a breath reading by the means to record a first breathing state ( whether accepted by the device as within the first breathing state parameter or not ). the breath reading acceptance means may comprise a switch or other similar member which must be activated in order for the first breathing state recordal means to record a breath reading . the reader &# 39 ; s attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification , and the contents of all such papers and documents are incorporated herein by reference . all of the features disclosed in this specification ( including any accompanying claims , abstract and drawings ), and / or all of the steps of any method or process so disclosed , may be combined in any combination , except combinations where at least some of such features and / or steps are mutually exclusive . each feature disclosed in this specification ( including any accompanying claims , abstract and drawings ), may be replaced by alternative features serving the same , equivalent or similar purpose , unless expressly stated otherwise . thus , unless expressly stated otherwise , each feature disclosed is one example only of a generic series of equivalent or similar features . the invention is not restricted to the details of the foregoing embodiment ( s ). the invention extend to any novel one , or any novel combination , of the features disclosed in this specification ( including any accompanying claims , abstract and drawings ), or to any novel one , or any novel combination , of the steps of any method or process so disclosed .
the invention provides a breath monitoring device comprising means to record a first breathing state of a user , and means to detect a deviation from the recorded breathing state in a subsequent use of the device by a user . the invention further provides a method of monitoring breaths , the method comprising the steps of : recording the first breathing state of a person from a breath of a person ; and detecting a deviation from the recorded first breathing state in a subsequent breath from a person .