System for ventilation of a being
AssigneeLoewenstein Medical Technology S.A.
InventorsPeter KREMEIER, Christian WOLL
Life of this patent
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Abstract
A system for ventilation of a being, comprising at least one ventilator and at least one EIT measuring device, the ventilator comprising at least one controllable respiratory gas source and a programmable control unit for controlling the respiratory gas source and the EIT measuring device comprising at least one sensor apparatus for measuring impedance values of at least one lung of the being and at least one calculation and evaluation unit, and the system assigning the impedance values measured by way of the at least one sensor apparatus to pixels n, and the control unit being configured as specified in the claims.
Claims20
System (1) for ventilation of a being (4), comprising at least one ventilator (2) and at least one EIT measuring device (3), the ventilator (2) comprising at least one controllable respiratory gas source (21) and a programmable control unit (22) for controlling the respiratory gas source (21) and the EIT measuring device (3) comprising at least one sensor apparatus (31) for measuring impedance values of at least one lung of the being and at least one calculation and evaluation unit (32), the system (1) assigning the impedance values measured by way of the at least one sensor apparatus (31) to pixels n, and the control unit (22) being configured
- a. to specify ventilation settings in a reference phase (R) of the respiratory gas source (21), impedance values being recorded at at least one point in time in the reference phase (R) and a first characteristic CR,n being calculated from the recorded impedance values for each pixel n, and
- b. to specify ventilation settings in at least one test phase (T1) of the respiratory gas source (21) following the reference phase (R), the ventilation settings differing from the ventilation settings of the reference phase (R) in at least one ventilation setting and impedance values being recorded at at least one point in time in the test phase (T1) and a second characteristic CT1,n being calculated from the recorded impedance values for each pixel n.
System according to at least one of the preceding claims, wherein at least one further test phase (Tm) follows the at least one test phase (T1), the ventilation setting of each further test phase (Tm) differing from the first test phase (T1) and the reference phase (R) in at least one ventilation setting and the system (1) recording impedance values at at least one point in time in each further test phase (Tm) and calculating a second characteristic CTm,n from the recorded impedance values for each pixel n.
System (1) according to at least one of the preceding claims, wherein both the reference phase (R) and each test phase (T1, Tm) comprise at least two breaths, the reference phase (R) and each test phase (T1, Tm) being able to be subdivided into at least two subphases, at least one subphase representing a habituation phase (G1, G2) and at least one subphase representing a measurement phase (M1, M2).
System (1) according to at least one of the preceding claims, wherein a positive end-expiratory pressure (PEEP) is applied during the expiration phase of each breath, and an inspiratory pressure Pinsp that is higher by the value ΔP or a tidal volume (VT) that is higher by an adjustable factor is applied during the inspiration phase.
System (1) according to at least one of the preceding claims, wherein an end-expiratory hold maneuver (EH1, EH2) is carried out at the end of at least one expiration phase, the end-expiratory hold maneuver (EH1, EH2) comprising holding the PEEP, wherein an end-inspiratory hold maneuver (IH1, IH2) is carried out at the end of at least one inspiration phase, the end-inspiratory hold maneuver (IH1, IH2) comprising a hold of the inspiratory pressure Pinsp.
System (1) according to at least one of the preceding claims, wherein the end-expiratory hold maneuver (EH1, EH2) and the end-inspiratory hold maneuver (IH1, IH2) are carried out during the measurement phase (M1, M2), the measurement phase (M1, M2) comprising at least two breaths and the end-expiratory hold maneuver (EH1, EH2) being carried out during the expiration phase of the second-to-last breath and the end-inspiratory hold maneuver (IH1, IH2) being carried out during the inspiration phase of the last breath.
System (1) according to at least one of the preceding claims, wherein impedance values are recorded and assigned to pixels n at at least two points in time both during the reference phase (R) and during the test phase (T1), the first point in time being during the end-expiratory hold maneuver (EH1, EH2) and the recorded impedance values being assigned to the pixels n as IMin,n, and the second point in time being during the end-inspiratory hold maneuver (IH1, IH2) and the recorded impedance values being assigned to the pixels n as IMax,n, the following values being calculated from the respective values IMin,n and IMax,n, in each case for the reference phase (R) and the test phase (T1):
- a. ΔIn for each pixel n as the difference between IMax,n and IMin,n,
- b. IMin,Sum as the sum of all IMin,n,
- c. IMax,Sum as the sum of all IMax,n,
- d. ΔIglobal as the difference between IMax,Sum and IMin,Sum,
- wherein the calculation for the respective pixel is only carried out and the pixel is only included in the sums TMax,Sum and TMin,Sum if ΔIn>0 applies to the pixel.
System (1) according to at least one of the preceding claims, wherein the respective characteristics CR,n and CT1,n of the reference and test phase, respectively, are each calculated from the ratio of ΔIn to ΔIglobal, where
- a. the ratio ΔIn to ΔIglobal of the reference phase is multiplied by a factor CR,Stat in order to calculate CR,n and
- b. the ratio ΔIn to ΔIglobal of the test phase is multiplied by a factor CT1,Stat in order to calculate CT1,n,
- where CR,Stat and CT1,Stat are determined from the pressure difference between the end-expiratory hold maneuver and the end-inspiratory hold maneuver and also the expiration volume of the breath preceding the breath during which the end-expiratory hold maneuver is carried out.
System (1) according to at least one of the preceding claims, wherein the characteristic CT1,n of each pixel n is compared to the characteristic CR,n of the same pixel n and the pixel n is assigned to one of at least two numerical groups, wherein
- a. the pixels n for which CT1,n is greater than CR,n are assigned to a first numerical group WIN and
- b. the pixels n for which CT1,n is less than CR,n are assigned to a second numerical group LOSS.
System (1) according to at least one of the preceding claims, wherein a characteristic is calculated from the characteristics CT1,n and CR,n for each pixel n of the respective numerical group, wherein
- a. a characteristic CWIN,n is calculated for the pixels n from the numerical group WIN and
- b. a characteristic CLOSS,n is calculated for the pixels n from the numerical group LOSS and
- c. a characteristic CWIN,global is calculated for the numerical group WIN with the sum of the characteristics CWIN,n and
- d. a characteristic CLOSS,global is calculated for the numerical group LOSS with the sum of the characteristics CLOSS,n.
System (1) according to at least one of the preceding claims, wherein the system (1) is configured to interpret the characteristics CWIN,global and CLOSS,global and to output the magnitude of the characteristics in alphanumeric and/or graphical fashion, with the ventilation setting by which the reference phase (R) and the test phase (T1) differ from one another being included in the interpretation of the characteristics CWIN,global and CLOSS,global.
System (1) according to at least one of the preceding claims, wherein a notification is generated on the basis of the interpretation of the characteristics CWIN,global and CLOSS,global, the notification containing at least one recommendation in respect of the ventilation settings and the notification being output in alphanumeric and/or graphical fashion.
System (1) according to at least one of the preceding claims, wherein the ventilation setting in respect of which the notification contains at least one recommendation is at least one of ΔP and/or PEEP.
System (1) according to at least one of the preceding claims, wherein, in the case of a PEEP setting which is elevated in the test phase (T1) in relation to the reference phase (R),
- a. the recommendation not to alter the ventilation settings is output if CWIN,global and CLOSS,global are below the set threshold,
- b. the recommendation to increase the PEEP is output if CWIN,global is above the set threshold and CLOSS,global is below the set threshold,
- c. the recommendation not to alter the PEEP and consider a reduction in the inspiratory pressure Pinsp and/or the expiratory tidal volume VT, wherein a test phase with reduced inspiratory pressure Pinsp should initially be set, is output if CWIN,global is below the set threshold and CLOSS,global is above the set threshold,
- d. the recommendation to increase the PEEP and consider a reduction in the inspiratory pressure Pinsp and/or expiratory tidal volume VT, wherein a test phase with reduced inspiratory pressure Pinsp should initially be set, is output if CWIN,global and CLOSS,global are above the set threshold,
- and/or, in the case of a PEEP setting which is reduced in the test phase (T1) in relation to the reference phase (R),
- e. the recommendation not to alter the ventilation settings and/or the recommendation to reduce the PEEP is output if CWIN,global and CLOSS,global are below the set threshold,
- f. the recommendation to reduce the PEEP is output if CWIN,global is above the set threshold and CLOSS,global is below the set threshold,
- g. the recommendation not to alter the setting of the PEEP and/or to increase the latter and to consider a recruitment maneuver is output if CWIN,global is below the set threshold and CLOSS,global is above the set threshold,
- h. the recommendation not to alter the setting of the PEEP and to consider a recruitment maneuver and, where possible, to reduce Pinsp and/or VT is output if CWIN,global and CLOSS,global are above the set threshold.
System (1) according to at least one of the preceding claims, wherein, in the case of a Pinsp and/or VT setting which is elevated in the test phase (T1) in relation to the reference phase (R),
- a. the recommendation not to alter the ventilation settings is output if CWIN,global and CLOSS,global are below the set threshold,
- b. the recommendation to increase the PEEP is output if CWIN,global is above the set threshold and CLOSS,global is below the set threshold,
- c. the recommendation to reduce the setting of the PEEP and/or of the Pinsp and/or of VT is output if CWIN,global is below the set threshold and CLOSS,global is above the set threshold,
- d. the recommendation to increase the PEEP and/or, where possible, to reduce the Pinsp and/or the tidal volume is output if CWIN,global and CLOSS,global are above the set threshold,
- and/or, in the case of a Pinsp and/or VT setting which is reduced in the test phase (T1) in relation to the reference phase (R),
- e. the recommendation not to alter the ventilation settings is output if CWIN,global and CLOSS,global are below the set threshold,
- f. the recommendation to reduce the PEEP and/or Pinsp and/or VT is output if CWIN,global is above the set threshold and CLOSS,global is below the set threshold,
- g. the recommendation to increase the PEEP is output if CWIN,global is below the set threshold and CLOSS,global is above the set threshold,
- h. the recommendation to increase the PEEP and, where possible, to reduce the Pinsp and/or the tidal volume is output if CWIN,global and CLOSS,global are above the set threshold.
System (1) according to at least one of the preceding claims, wherein findings are established on the basis of the interpretation of the characteristics CWIN,global and CLOSS,global.
System (1) according to at least one of the preceding claims, wherein the notification also contains at least one finding in addition to the recommendation.
The system (1) as claimed in at least one of the preceding claims, wherein the control device (22) is designed to automatically carry out the output recommendations and to implement corresponding ventilation settings.
System (1) for ventilation of a being (4), comprising at least one ventilator (2) and at least one EIT measuring device (3), the ventilator (2) comprising at least one controllable respiratory gas source (21) and a programmable control unit (22) for controlling the respiratory gas source (21) and the EIT measuring device (3) comprising at least one sensor apparatus (31) for measuring impedance values of at least one lung of the being and at least one calculation and evaluation unit (32), the system (1) assigning the impedance values measured by way of the at least one sensor apparatus (31) to pixels n, and the system (1) being configured to carry out the following method steps:
- a. habituating (101) the being (4) to ventilation settings in a reference phase R,
- b. measuring (102) impedances of the lung of the being (4) during the reference phase R,
- c. habituating (103) the being (4) to ventilation settings in a test phase T1,
- d. measuring (104) impedances of the lung of the being (4) during the test phase T1,
- e. calculating (105, 106) characteristics CR,n and CT1,n from the impedance values from the measurement step (102, 104),
- f. comparing (107) the characteristics CR,n and CT1,n,
- g. classifying (108) the characteristics CR,n and CT1,n in numerical groups WIN and LOSS,
- h. calculating (109, 110) characteristics CWIN,global and CLOSS,global,
- i. comparing (111, 112) the characteristics CWIN,global and CLOSS,global to thresholds,
- j. evaluation (113), the evaluation (113) at least comprising the generation of a graphical representation of the characteristics CWIN,global and CLOSS,global and the evaluation step (113) optionally comprising the establishment of findings taking into account the characteristics CWIN,global and CLOSS,global,
- k. recommendation (114), the recommendation (114) at least comprising the generation of an alphanumeric output of recommendations in respect of the ventilation settings.
Method for ventilation of a being using a system (1) for ventilation of a being (4), comprising at least one ventilator (2) and at least one EIT measuring device (3), the ventilator (2) comprising at least one controllable respiratory gas source (21) and a programmable control unit (22) for controlling the respiratory gas source (21) and the EIT measuring device (3) comprising at least one sensor apparatus (31) for measuring impedance values of at least one lung of the being and at least one calculation and evaluation unit (32), the system (1) assigning the impedance values measured by way of the at least one sensor apparatus (31) to pixels n, and the control unit (22)
- a. specifying ventilation settings in a reference phase R of the respiratory gas source (21), impedance values being recorded at at least one point in time in the reference phase (R) and a first characteristic CR,n being calculated from the recorded impedance values for each pixel n, and
- b. specifying ventilation settings in at least one test phase (T1) of the respiratory gas source (21) following the reference phase (R), the ventilation settings differing from the ventilation settings of the reference phase (R) in at least one ventilation setting and impedance values being recorded at at least one point in time in the test phase (T1) and a second characteristic CT1,n being calculated from the recorded impedance values for each pixel n.
Dependencies are inferred from the claim text.