Patent Application
20230346308
The invention relates to a method of measuring a hypoxic session index as a measure of the response of a patient to hypoxic training or to a hypoxic session, with measurement of an index that characterizes the peripheral oxygen saturation in the patient’s blood and/or the response of the pulse. The invention further relates to a device for carrying out the method.
Methods for performing a hypoxic therapy session are known from the prior art:
DE 10 2012 010 806 A1 discloses a hypoxic therapy session in which the values of peripheral oxygen saturation and of the pulse of a patient are sent to a monitoring device, while a hypoxic gas mixture is supplied to the patient in alternation with a normoxic or hyperoxic gas mixture. The hypoxic gas mixture and the normoxic or hyperoxic gas mixture are supplied in each case over a predetermined hypoxic period.
The known methods provide comparatively little support in the evaluation of the data obtained in hypoxic training.
It is therefore an object of the present invention to specify a method in which the data obtained in hypoxic training are evaluated in the form of quantitative results. It is also an object to provide a device for carrying out the method.
This object is achieved according to the invention by a method according to claim 1 and a device according to claim 14. Advantageous embodiments result from the respectively dependent claims.
The method according to the invention includes the following steps:
The difference between the data curve and the reference curve allows for a quantitative evaluation of the measured values of oxygen saturation. The index is in particular the oxygen saturation or the partial pressure of oxygen dissolved in the blood of the patient, the relationship of which is represented by the oxygen binding curve having a sigmoidal profile. The difference is determined, in particular, by a distance between the data curve and the reference curve or by a comparison of surfaces that are limited by the data curve or the reference curve.
A hypoxic safety value, which, in particular, indicates the smallest value to which the index may drop in the hypoxic phase, is in particular between 70% and 88% of the mean value of the index in the initial phase, in particular 80% of the mean value of the index in the initial phase.
In the initial phase, the patient is, in particular, under no physical stress and breathes ambient air. The patient is in a resting position, in particular lying on a couch. In the initial phase, the device for performing the measurement of the hypoxic session index is calibrated, in particular. The initial phase is in particular between 1 minute and 5 minutes. In the initial phase, the index, for example the partial pressure of oxygen, is measured and recorded in each second, in particular in a period between 20 seconds and 120 seconds, in particular 30 seconds before the start of the first hypoxic phase. After the end of the initial phase, the mean value of the index is calculated for determining a baseline of the index during hypoxic training. The defined hypoxic period and/or hyperoxic period is in particular between 1 minute and 15 minutes. The mean value of the index in the initial phase according to step II is determined in particular before the hypoxic phase according to step III, preferably during the initial phase or at the end of the initial phase. In an alternative embodiment of the method, the hypoxic phase according to step III and the hyperoxic phase according to step IV are interchanged.
An advantageous embodiment of the method is characterized in that the reference curve is a data curve which is determined for a reference person after steps I to V, or a data curve which is calculated by averaging data curves of a plurality of reference persons, wherein the data curves are determined after steps I to V for the reference persons.
A reference person is, in particular, a person which shows measured values of the index that are classified as healthy. The reference curve can also be ascertained by averaging the measured values of the index of the reference persons at the respective same time of the method for several reference persons. If necessary, the reference persons can be grouped according to their physical characteristics.
In some embodiments of the method, the hypoxic session index is shown as a list of indices, in particular indices that are shown in the following text.
The method is advantageously characterized by setting a hypoxic cycle score (HCS) in the hypoxic phase for determining the hypoxic session index, the following steps being performed:
The HCS serves to compare the drop in the reference curve and the data curve in the hypoxic phase.
The HCS reference value is, in particular, between 88% and 92% of the mean value of the index from the initial phase, preferably 90% of the mean value of the index from the initial phase.
The HCS determination area is defined, in particular, as an area between the data curve from the time at which the index on the data curve has dropped to the HCS reference value, up to the end of the hypoxic phase and the HCS reference line from the time at which the index has dropped to the HCS reference value, up to the end of the hypoxic phase.
The HCS reference area is defined, in particular, as an area between the data curve from the time at which the index on the reference line has dropped to the HCS reference value, up to the end of the hypoxic phase and the HCS reference line from the time at which the index has dropped to the HCS reference value up to the end of the hypoxic phase.
The hypoxic cycle score (HCS) is determined, in particular, by the absolute difference between the HCS determination area and the HCS reference area, which is defined in particular by the HCS area difference. Alternatively, the hypoxic cycle score is determined by the relative difference between the HCS determination area and the HCS reference area, in which the HCS area difference is related to the HCS reference area. The relative difference is given, in particular, in percent.
A preferred embodiment of the method is characterized by setting a reoxygenation max score (RMS) in the reoxygenation phase for determining the hypoxic session index by the following steps:
The reoxygenation max score serves to compare the reference curve and the data curve in the reoxygenation phase.
The RMS safety time is preferably 30 seconds to 50 seconds, preferably 45 seconds, after the start of the reoxygenation phase. The RMS safety time is preferably a time at which the index assumes between 3% and 10% of the mean value of the index from the initial phase.
The RMS determination area is defined, in particular, as an area between the data curve from the RMS safety time to the end of the reoxygenation phase and the RMS safety line from the RMS safety time to the end of the reoxygenation phase.
The RMS reference area is defined, in particular, as an area between the reference curve from the RMS safety time to the end of the reoxygenation phase and the RMS safety line from the RMS safety time to the end of the reoxygenation phase.
The reoxygenation max score (RMS) is determined, in particular, by the absolute difference between the RMS determination area and the RMS reference area, which is defined in particular by the RMS area difference. Alternatively, the reoxygenation max score is determined by the relative difference between the RMS determination area and the RMS reference area, in which the RMS area difference is related to the RMS reference area. The relative difference is given, in particular, in percent.
The reference curve increases, in particular, to 99% of the value of the index which the index can reach at most in the initial phase. If the index is the partial pressure of oxygen or the oxygen saturation, the reference curve will increase in particular to 99% of the partial pressure of oxygen or to 99% of the oxygen saturation as the most healthy value of the index; this applies to those cases where the entire hemoglobin in the blood is loaded with oxygen. The reference curve will preferably increase to the most healthy value of the index in a period from 10 seconds to 14 seconds, preferably 12 seconds, after the RMS safety time.
A development of the above-mentioned embodiment of the method is characterized by determining a user reoxygenation potential as a measure of the difference between a predetermined reference reoxygenation max score and the reoxygenation max score determined in step XIX. The user reoxygenation potential is, in particular, the aforementioned difference, expressed in percent. The reference reoxygenation max score is, in particular, 99% of the maximum value which the index can reach in the initial phase.
Preferred embodiments of the method are characterized by setting a dynamic score in the hypoxic phase for determining the hypoxic session index, having the steps: XX. Determining a DS reference time at which the index in the hypoxic phase has dropped to a defined DS reference value, wherein the DS reference value is smaller than the mean value of the index in the initial phase and greater than the hypoxic safety value; XXI. Determining the dynamic score as a measure of the time difference between the DS reference time and a defined DS reference time interval.
The dynamic score serves to indicate the response time of the body of a patient to oxygen deficiency, measured from the start of the hypoxic phase, in particular, until a response of the body can be measured at a sensor.
The defined DS reference value is, in particular, 95% to 98%, preferably 97% of the mean value of the index from the initial phase. The DS reference time interval is, in particular, between 40 seconds and 50 seconds, preferably 45 seconds. The time difference between the DS reference time and the DS reference time interval is recorded as the value of the dynamic score. In case of negative time difference values and/or time difference values that are greater than a predetermined value, in particular more than 184 seconds, the dynamic score is preferably set to zero. Alternatively or additionally, the measurement time in the initial phase and the hypoxic phase may be divided into time intervals, wherein each time interval is assigned a hypoxic improvement potential such that a position of the DS reference time in a certain time interval corresponds to a certain hypoxic improvement potential
The method is advantageously characterized by setting a reoxygenation impulse score in the reoxygenation phase for determining the hypoxic session index, having the steps:
The reoxygenation impulse score serves to indicate the response time of the body of a patient to a hyperoxic gas mixture, measured from the start of the hyperoxic phase, in particular until a response of the body to the hyperoxic gas mixture can be measured by a sensor.
The defined hyperoxic reference value is, in particular, 2% to 5%, preferably 3% of the mean value of the index from the initial phase. The RI reference time interval is, in particular, between 40 seconds and 50 seconds, preferably 45 seconds.
In case of negative time difference values and/or time difference values that are greater than a predetermined value, in particular, more than 184 seconds, the reoxygenation impulse score is preferably set to zero. Alternatively or additionally, the measurement time in the reoxygenation phase may be divided into time intervals, wherein each time interval is assigned a reoxygenation improvement potential such that a position of the RI reference time in a certain time interval corresponds to a certain reoxygenation improvement potential.
One embodiment of the method is characterized by setting an oxygen recovery score in the reoxygenation phase for determining the hypoxic session index by the reoxygenation impulse score and the reoxygenation max score, in particular, by averaging.
Averaging is, in particular, an arithmetic averaging.
Advantageously, the index of the oxygen content is the partial pressure of oxygen and/or the oxygen saturation. These indices indicate what percentage of the total hemoglobin in the blood of a patient is loaded with oxygen.
A further embodiment of the method is characterized by determining a baseline potential as a measure of the difference between a predetermined ideal value of the oxygen saturation index and the mean value of the oxygen saturation index from the initial phase. The predetermined ideal value of the oxygen saturation index is, in particular, 99% of the value of the index which the index can reach at most in the initial phase.
An advantageous embodiment of the method is characterized by setting a lower boundary line and an upper boundary line, wherein the lower boundary line in the hypoxic phase shows smaller values of the index than the reference curve, and the upper boundary line shows greater values of the index than the reference curve at the respective same measurement times, wherein the boundary lines are determined, in particular, from measurements of the index in one or more subjects, wherein only values of the index are considered for determining the hypoxic session index, which values are smaller than the value of the index in the upper boundary line and greater than the value of the index in the lower boundary line at the time of measurement of the respective value of the index.
In particular, only data points which lie in the area defined by the reference curves are used to calculate the reference areas and determination areas mentioned in the application. In the context of the application, this area is referred to as the normal hypoxic range and defines the range of the valid measured values. Values of the index that are outside the area defined by the boundary line at the respective time are classified as incorrect measurement values, for example as a result of poor contact between the sensor and the patient. The boundary lines are, in particular, previously measured data curves of subjects with suitable values of the index for the upper and lower boundary line.
A preferred embodiment of the method is characterized by determining the hypoxic session index by changing a pulse curve of the patient during steps III to V. In particular, an increase or decrease in the pulse during hypoxic training may be used as an indicator of the response of the body to hypoxic training.
A development of the above-mentioned embodiment of the method is characterized by determining a heart rate relaxation score by plotting a pulse curve against time during hypoxic training, having the following steps:
The heart rate baseline is determined, in particular, in the initial phase, wherein the pulse is measured and recorded in every second in order to determine the heart rate baseline from the mean value of the pulse in the initial phase. The heart rate relaxation score is used to indicate the change in the pulse during hypoxic training. This indicates relaxation of the patient during hypoxic training.
The maximum value of the pulse above the heart rate baseline is used to determine a negative heart rate relaxation score, and the smallest value of the pulse below the heart rate baseline is used to determine a positive heart rate relaxation score. The positive heart rate relaxation score, in particular, is used to determine the response of the patient’s body to hypoxic training.
One embodiment of the method is characterized by one or more repetitions of steps III to V before determining the hypoxic session index according to step VI. In each repetition, referred to, in particular, as a cycle, one or more of the aforementioned indices can be determined in order to form mean values for the respective index therefrom or to compare values of the respective indices in order to detect values incorrectly measured in a cycle.
A device for carrying out a method according to one of the aforementioned embodiments comprises a mask for supplying the hypoxic, normoxic and/or hyperoxic gas mixture to the patient, a controller for controlling the device, and a finger clip for measuring the pulse and/or the index.
Such a device makes it possible to quantitatively detect suitable indices for determining the response of the body of a patient.
One embodiment of the device comprises a mobile application for representing the hypoxic session index and/or at least one of the indices for determining the hypoxic session index according to one of the aforementioned embodiments. The hypoxic session index can be represented by colors of a color scale in order to allow for rapid detection of the response of the body of a patient to hypoxic training. Alternative embodiments of the device comprise a stationary application for representing the hypoxic session index and/or at least one of the indices for determining the hypoxic session index according to one of the aforementioned embodiments.
Further advantages of the invention can be found in the description and the drawings. Likewise, the aforementioned features and those which are to be explained below can each be used individually or together in any desired combinations. The embodiments shown and described are not to be understood as an exhaustive list, but, rather, have an exemplary character for the description of the invention.
In addition, the device has a controller 18 for controlling the device 10 and a finger clip 20 and a sensor 22, in particular, arranged in the finger clip 20, for measuring a pulse RR (see
A predetermined HCS reference value of the index is smaller than the mean value of the index in the initial phase and is greater than the hypoxic safety value 52. The HCS reference value is shown as the HCS reference line 54 of the hypoxic phase against the measurement time MT. An HCS determination area 56 is defined as an area between the data curve 46 and the HCS reference line 54 in the hypoxic phase HP. An HCS reference area 58 is determined as an area between the reference curve 48 and the HCS reference line 54 in the hypoxic phase, the end of which is represented by a vertical line. The value of the hypoxic cycle score HCS is defined as a measure of the ratio and/or the difference between the HCS determination area 56 and the HCS reference area 58.
The DS reference value DBW is smaller than the mean value of the index KG in the initial phase AP and is greater than the hypoxic safety value 52 (see
Alternatively or additionally, the measurement time in the initial phase AP and the hypoxic phase HP may be divided into time intervals ZI, wherein each time interval ZI is assigned a hypoxic improvement potential, represented by different hatching in the time intervals ZI, such that a position of the DS reference time DRZ in a certain time interval corresponds to a certain hypoxic improvement potential.
The time difference between the RI reference time RZP and a defined RI reference time interval, in particular an RI reference time interval of 40 seconds to 50 seconds, is recorded as the value of the reoxygenation impulse score RIS. In case of negative time difference values and/or time difference values that are greater than a predetermined value, in particular, more than 184 seconds, the reoxygenation impulse score RIS is preferably set to zero. Alternatively or additionally, the measurement time MT in the reoxygenation phase RP may be divided into time intervals ZI, wherein each time interval ZI is assigned a reoxygenation improvement potential, represented by different hatching, such that a position of the RI reference time RZP in a certain time interval ZI corresponds to a certain reoxygenation improvement potential.
In this case, the first data curve 46a reaches the RMS safety value RSW at an earlier time than the reference curve 48, and the second data curve 46b reaches the RMS safety value RSW at a later time than the reference curve 48. The horizontal line 62 schematically identifies a maximum value of the index KG, which the reference curve 48, the first data curve 46a and the second data curve 46b adopt in this exemplary embodiment in the reoxygenation phase RP. The cross-hatched area and the roughly hatched area below the reference curve together form the RMS reference area RRF. The reoxygenation max score RMS of the first data curve 46a is defined as the ratio of the total area of finely hatched area, cross-hatched area and roughly hatched area below the first data curve as the RMS determination area RBF1 and the RMS reference area RRF. The reoxygenation max score RMS of the second data curve is defined as the ratio of the roughly hatched area below the second data curve as the RMS determination area RBF2 and the RMS reference area RRF.
The respective user reoxygenation potential URP (see
The display 74 has a second display panel 76b, where the values of the partial pressure of oxygen SpO2 are plotted as the partial pressure of oxygen curve 80, and the values of the pulse RR of the patient are plotted as a pulse curve 64 against the measurement time MT. The left scale of the second display panel 76b refers to the partial pressure of oxygen SpO2, stated in percent. The right scale refers to the pulse RR, stated in bpm (beats per minute). The horizontal axis indicates the measurement time MT during hypoxic training.
When viewing all figures of the drawing in combination, the invention relates to a method 100 of measuring a hypoxic session index HSI as a measure of the response of a patient to hypoxic training, with measurement of an index KG that characterizes the oxygen content in the patient’s blood. The index KG is, in particular, the oxygen saturation and/or the partial pressure of oxygen SpO2. The patient is first supplied with a normoxic gas mixture 16 in an initial phase AP. Subsequently, in a hypoxic phase HP, the patient is supplied with a hypoxic gas mixture 14 over a defined hypoxic period. Subsequently, the patient is supplied with a normoxic or hyperoxic gas mixture 16 in a reoxygenation phase RP, in particular over a period of 1 minute to 10 minutes. The reoxygenation phase RP extends from the time from which the patient is supplied with the normoxic or hyperoxic gas mixture 16, over a defined hyperoxic period, wherein the index KG attains a hyperoxic reference value HRW of the index KG, and over a subsequent predetermined concluding period. The hypoxic session index HSI is determined from the differences between a data curve 46, 46a, 46b having the measurements of the index plotted against the respective measurement time MT of the index KG and a predetermined reference curve 48.
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| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2020 215 742.1 | Dec 2020 | DE | national |
This continuation application claims priority to PCT/EP2021/083816 filed on Dec. 1, 2021 which has published as WO 2022/122511 A1 and also the German application number 10 2020 215 742.1 filed on Dec. 11, 2020, the entire contents of which are fully incorporated herein with these references.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/EP2021/083816 | Dec 2021 | WO |
| Child | 18331074 | US |
