Method and apparatus for treating hyperarousal disorder
Systems or apparatus may be configured with method(s) for hyperarousal disorder such as for determining settings that control respiratory therapy for slowing a patients breathing. They may be configured to determine an interim target breathing rate less than a current spontaneous rate. They may be configured to derive target inspiratory time and expiratory times based on the interim target breathing rate. They may be configured to compute, with first function(s), a parameter set for generating a variable treatment pressure waveform based on target inspiratory/expiratory times. They may be configured to determine pressure settings by generating the waveform with the computed parameter set and second function(s). They may be configured to reduce the interim target breathing rate in response to a subsequent spontaneous breathing rate slowing down toward the interim target rate. They may be configured to generate feedback such as graphics/sound to provide information to promote slowing of breathing.
1. A method of determining settings for control of bi-level respiratory pressure therapy for slowing a patient's breathing, the method comprising:
determining an interim target breathing rate that is less than a current spontaneous breathing rate of the patient;
deriving a target inspiratory time and a target expiratory time, each of the target inspiratory time and the target expiratory time being derived based on the interim target breathing rate;
computing, with one or more first functions, a set of parameters for generating a variable treatment pressure waveform based on the target inspiratory time and the target expiratory time, wherein the set of parameters comprise a plurality of pressure values and a plurality of exponents, wherein the plurality of pressure values represent endpoints of the variable treatment pressure waveform during inspiratory and expiratory phases of the variable treatment pressure waveform, and the plurality of exponents shape a curvature of the variable treatment pressure waveform during the inspiratory and expiratory phases;
determining pressure settings by generating the variable treatment pressure waveform with the computed set of parameters and one or more second functions; and
reducing the interim target breathing rate in response to a subsequent spontaneous breathing rate of the patient slowing down toward the interim target breathing rate; and
controlling a blower to generate the bi-level respiratory pressure therapy according to the determined pressure settings.
2. The method of claim 1 , wherein the one or more second functions when applied with the computed set of parameters generate the variable treatment pressure waveform with an inspiratory portion having a continuous rise until the target inspiratory time is reached.
3. The method of claim 1 , wherein the one or more second functions when applied with the computed set of parameters generate the variable treatment pressure waveform with an expiratory portion having a continuous fall until the target expiratory time is reached.
4. The method of claim 1 , wherein the one or more second functions are in two-part form, wherein one part generates a target inspiratory portion between a trigger point and the target inspiratory time, and wherein the other part generates a target expiratory portion between a cycle point and a target total time.
5. The method of claim 4 , wherein the one or more second functions for the target inspiratory portion have a parametrised form as follows:
K 1+( K 2× t ) K3
wherein t represents time and K1, K2, and K3 are parameters of the computed set of parameters or more second functions for the target inspiratory portion.
6. The method of claim 5 , wherein the one or more second functions for the target expiratory portion have a parametrised form as follows:
K 4+( K 5×( t −tgtTi)) K6
wherein t represents time and K4, K5, and K6 are parameters of the computed set of parameters for the target expiratory portion and tgtTi is the target inspiratory time.
7. The method of claim 6 , wherein computing the set of parameters comprises computing K2 such that the target inspiratory portion starts from K1 and reaches K4 when t is equal to the target inspiratory time, wherein K1 and K4 are pressure levels of the plurality of pressure values and K3 is an exponent of the plurality of exponents.
8. The method of claim 6 , wherein computing the set of parameters comprises computing K5 such that the target expiratory portion starts from K4 and reaches K1 when t is equal to the target total time, wherein K1 and K4 are predetermined pressure levels and K6 is a predetermined e.
9. The method of claim 1 , wherein deriving the target inspiratory time and the target expiratory time comprises:
determining a target total time as a reciprocal of the interim target breathing rate; and
partitioning the target total time into the target inspiratory time and the target expiratory time.
10. The method of claim 9 , wherein the target total time is partitioned according to a predetermined target proportion.
11. The method of claim 1 further comprising recomputing, with the one or more first functions, the set of parameters for generating the variable treatment pressure waveform based on a second target inspiratory time and a second target expiratory time that are both derived with the reduced interim target breathing rate.
12. The method of claim 1 , wherein reducing the interim target breathing rate comprises reducing the interim target breathing rate according to a predetermined schedule to an optimal breathing rate.
13. The method of claim 12 , further comprising aborting the predetermined schedule in response to a sudden increase in the patient's breathing rate.
14. The method of claim 12 further comprising accessing a second, predetermined schedule to alter a progress of reductions of the interim target breathing rate for a new therapy session.
15. The method of claim 14 wherein the accessing of the second predetermined schedule is based on an assessment of progress of the patient's breathing rate reductions in one or more prior therapy sessions.
16. The method of claim 1 , further comprising generating biofeedback for the patient, the biofeedback being configured to further encourage the patient's breathing rate to slow down toward the interim target breathing rate.
17. The method of claim 16 , wherein generating biofeedback comprises:
displaying, on a graphical display, an annular graphic, wherein one portion of the annular graphic represents an inspiratory portion, and another portion of the annular graphic represents an expiratory portion, and
displaying, on the graphical display, a marker graphic moving along the annular graphic at the target breathing rate,
wherein the marker graphic traverses the inspiratory portion of the annular graphic during the target inspiratory time.
18. The method of claim 17 further comprising varying a display characteristic of the marker graphic according to a difference between the target breathing rate and a spontaneous breathing rate of the patient.
19. The method of claim 1 further comprising:
recomputing another set of the set of parameters for generating the variable treatment pressure waveform based on another target inspiratory time and another target expiratory time that are both derived with the reduced interim target breathing rate;
determining other pressure settings by generating the variable treatment pressure waveform with the computed other set of parameters and the one or more functions; and
controlling the blower to generate the bi-level respiratory pressure therapy according to the determined other pressure settings.
20. A computing device comprising a display and a controller configured to execute the method of claim 1 .
21. A computer-readable medium having encoded thereon computer-readable instructions that when executed by a controller of a device cause the controller to perform the method of claim 1 .
22. The method of claim 1 , wherein during an introductory period, the set of parameters for generating a variable treatment pressure waveform are computed based on a spontaneous patient inspiratory time and a spontaneous patient expiratory time.
23. The method of claim 1 , wherein the plurality of exponents comprises an expiratory exponent and an inspiratory exponent.
24. A respiratory pressure therapy device comprising:
a blower configured to generate a variable pressure at a patient interface according to a variable treatment pressure waveform,
at least one sensor configured to detect a spontaneous breathing rate of the patient, and
a controller coupled with the blower and the at least one sensor, the controller configured to:
determine an interim breathing rate target that is less than a current spontaneous breathing rate of the patient,
derive a target inspiratory time and a target expiratory time, each of the target inspiratory time and the target expiratory time being derived based on the interim breathing rate target,
compute, with one or more first functions, a set of parameters for generating the variable treatment pressure waveform based on the target inspiratory time and the target expiratory time, wherein the set of parameters comprise a plurality of pressure values and a plurality of exponents, wherein the plurality of pressure values represent endpoints of the variable treatment pressure waveform during inspiratory and expiratory phases of the variable treatment pressure waveform, and the plurality of exponents shape a curvature of the variable treatment pressure waveform during the inspiratory and expiratory phases,
determine pressure settings for generating the variable pressure to the patient interface by generating the variable treatment pressure waveform with the computed set of parameters and one or more second functions,
reduce the interim breathing rate target in response to a subsequent spontaneous breathing rate of the patient slowing down toward the interim breathing rate target; and
control the blower according to the pressure settings.
25. The respiratory pressure therapy device of claim 24 , wherein the controller is further configured to generate biofeedback for the patient.
26. The respiratory pressure therapy device of claim 25 , wherein the controller is further configured to generate biofeedback for the patient by controlling a local external computing device in communication with the controller of the respiratory pressure therapy device.