U.S. patent application number 15/124298 was filed with the patent office on 2017-01-19 for pressure range adjustment for respiratory therapy device.
The applicant listed for this patent is FISHER & PAYKEL HEALTHCARE LIMITED. Invention is credited to David Robin WHITING, Simei Gomes WYSOSKI.
Application Number | 20170014587 15/124298 |
Document ID | / |
Family ID | 54071009 |
Filed Date | 2017-01-19 |
United States Patent
Application |
20170014587 |
Kind Code |
A1 |
WHITING; David Robin ; et
al. |
January 19, 2017 |
PRESSURE RANGE ADJUSTMENT FOR RESPIRATORY THERAPY DEVICE
Abstract
An automatic positive airway pressure (AutoPAP) therapy device
can be configured such that the minimum and/or maximum pressures
deliverable by the device can automatically change. The minimum
and/or maximum pressures can change as a function of pressures
delivered over the course of the current therapy session and/or
over the course of prior therapy sessions. The minimum and/or
maximum pressures can also change as a function of the presence,
absence, type, severity, or length of sleep disordered breathing
events (SDBE) detected by the device over the course of the current
therapy session and/or over the course of prior therapy
sessions.
Inventors: |
WHITING; David Robin;
(Auckland, NZ) ; WYSOSKI; Simei Gomes; (Auckland,
NZ) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
FISHER & PAYKEL HEALTHCARE LIMITED |
Auckland |
|
NZ |
|
|
Family ID: |
54071009 |
Appl. No.: |
15/124298 |
Filed: |
March 10, 2015 |
PCT Filed: |
March 10, 2015 |
PCT NO: |
PCT/IB2015/051717 |
371 Date: |
September 7, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61950746 |
Mar 10, 2014 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61M 16/06 20130101;
A61B 5/087 20130101; A61M 16/024 20170801; A61M 16/08 20130101;
A61M 2016/0027 20130101; A61M 2016/0039 20130101; A61M 2205/3375
20130101; A61M 2230/06 20130101; A61B 5/0205 20130101; A61B 5/4818
20130101; A61M 2230/205 20130101; A61M 16/0069 20140204; A61M
16/0672 20140204; A61M 2205/3365 20130101; A61M 16/1095 20140204;
A61M 2205/3303 20130101; A61M 16/16 20130101; A61M 2016/0033
20130101; A61M 2210/0618 20130101; A61M 2205/52 20130101; A61M
2230/10 20130101; A61B 5/4836 20130101; A61M 2205/3653 20130101;
A61M 2230/202 20130101; A61M 16/04 20130101; A61M 2205/505
20130101; A61M 2230/43 20130101; A61M 16/109 20140204 |
International
Class: |
A61M 16/00 20060101
A61M016/00; A61M 16/16 20060101 A61M016/16; A61M 16/06 20060101
A61M016/06; A61M 16/08 20060101 A61M016/08; A61B 5/00 20060101
A61B005/00; A61B 5/0205 20060101 A61B005/0205 |
Claims
1. A respiratory therapy system comprising: a flow generator
adapted to provide pressurized gases to a patient, a sensor adapted
to measure at least one characteristic capable of being used to
determine one or more traits of a sleep-disordered breathing event
(SDBE) of the patient, and a hardware controller configured to:
receive the at least one characteristic measured by the sensor,
determine the one or more traits of the SDBE of the patient by
analyzing the at least one characteristic, repeatedly adjust a
pressure window comprising a minimum pressure limit and a maximum
pressure limit in response to one or more parameters measured
during the course of the current therapy session and/or one or more
previous therapy sessions, the one or more parameters including at
least pressure delivered or the determined one or more traits of
the SDBE; and control the flow generator to deliver pressurized
gases, the pressure of the pressurized gases being at least in part
based on the determined one or more traits of the SDBE, and the
pressure of the pressurized gases being greater than or equal to
the minimum pressure limit and less than or equal to the maximum
pressure limit, wherein the minimum pressure limit is less than the
maximum pressure limit.
2. The respiratory therapy system of claim 1, wherein the
characteristics capable of being used to determine the one or more
traits of the SDBE include one or more of the following: gas
pressure, gas flow, sound, flow generator current, flow generator
speed, flow generator motor torque, motion, tidal volume, heart
rate, lung volume, EEG signal, breath composition, blood oxygen
concentration, and blood CO2 concentration.
3. The respiratory therapy system of claim 1, wherein the traits of
the SDBE include one or more of the following: presence of the
SDBE, absence of the SDBE, type of the SDBE, severity of the SDBE,
length of the SDBE, and latency of the SDBE.
4. The respiratory therapy system of claim 1, wherein the
controller may make a decision to maintain or adjust the minimum
pressure limit or the maximum pressure limit on an event-by-event
basis.
5. The respiratory therapy system of claim 1, wherein the therapy
sessions comprise only the current therapy session.
6. The respiratory therapy system of claim 1, wherein the therapy
sessions comprise only one or more previous therapy sessions.
7. The respiratory therapy system of claim 1, wherein the therapy
sessions comprise both the current therapy session and one or more
previous therapy sessions.
8. The respiratory therapy system of claim 1, wherein the pressure
window is adjusted in response to the pressure delivered during the
course of the current therapy session and/or one or more previous
therapy sessions.
9. The respiratory therapy system of claim 8, wherein the minimum
pressure limit or the maximum pressure limit is adjusted in
response to the pressure delivered during one or more previous
therapy sessions.
10. The respiratory therapy system of claim 9, wherein the
delivered pressure at which the patient spent a percentage of time
at or below over the course of one or more previous therapy
sessions is recorded, and the minimum pressure limit or the maximum
pressure limit is adjusted to a function of the recorded
pressure.
11. The respiratory system of claim 9, wherein if the patient
spends a time at the maximum pressure limit that is greater than or
equal to a threshold percentage of time at the maximum pressure
limit over the course of one or more previous therapy sessions, the
maximum pressure limit is increased.
12. The respiratory system of claim 9, wherein if the patient
spends a time at the maximum pressure limit that is less than or
equal to a threshold percentage of time at the maximum pressure
limit over the course of one or more previous therapy sessions, the
maximum pressure limit is decreased.
13. The respiratory system of claim 8, wherein if the patient
experiences a number of delivered pressure increases greater than a
predetermined number over a predetermined period of time at or near
the minimum pressure limit, the minimum pressure limit is
increased.
14. The respiratory system of claim 1, wherein the respiratory
system comprises an automatic positive airway pressure therapy
system.
15. The respiratory therapy system of claim 1, wherein the minimum
pressure limit or the maximum pressure limit is adjusted during a
therapy session.
16. The respiratory therapy system of claim 15, wherein both the
minimum pressure limit and the maximum pressure limit are adjusted
during the therapy session.
Description
INCORPORATION BY REFERENCE TO ANY PRIORITY APPLICATIONS
[0001] This application is a national phase of PCT/IB2015/051717,
filed Mar. 10, 2015, entitled "PRESSURE RANGE ADJUSTMENT FOR
RESPIRATORY THERAPY DEVICE," which claims priority to U.S. Prov.
Pat. App. 61/950,746, filed Mar. 10, 2014, entitled "PRESSURE RANGE
ADJUSTMENT FOR RESPIRATORY THERAPY DEVICE." The application
identified in this paragraph is incorporated by reference herein in
its entirety. Any and all applications for which a foreign or
domestic priority claim is identified in the Application Data Sheet
as filed with the present application are hereby incorporated by
reference under 37 CFR 1.57.
FIELD OF THE DISCLOSURE
[0002] The present disclosure generally relates to respiratory
therapy devices. More particularly, the present disclosure relates
to control systems for use with respiratory therapy devices.
BACKGROUND
[0003] Respiratory disorders deal with the inability of a sufferer
to effect a sufficient exchange of gases with the environment,
leading to an imbalance of gases in the sufferer. These disorders
can arise as a pathological consequence of an obstruction of the
airway, insufficiency of the lungs in generating negative pressure,
an irregularity in the nervous function of the brain stem, or some
other physiological complication. Treatment of such disorders is
diverse and depends on the particular respiratory disorder being
targeted. In the first instance, a constriction of the airway,
otherwise known as an obstructive apnea or a hypopnea (collectively
referred to as obstructive sleep apnea or OSA), can occur when the
muscles that normally keep the airway open in a patient relax
during slumber to the extent that the airway is constrained or
completely closed off, a phenomenon often manifesting itself in the
form of snoring. When this occurs for a significant period of time,
the patient's brain typically recognizes the threat of hypoxia and
partially wakes the patient in order to open the airway so that
normal breathing may resume. The patient may be unaware of these
occurrences, which may occur as many as several hundred times per
session of sleep. This partial awakening may significantly reduce
the quality of the patient's sleep, over time potentially leading
to a variety of symptoms, including chronic fatigue, elevated heart
rate, elevated blood pressure, weight gain, headaches,
irritability, depression and anxiety.
[0004] Obstructive sleep apnea is commonly treated with the
application of positive airway pressure (PAP) therapy. PAP therapy
involves delivering a flow of gas to a patient at a therapeutic
pressure above atmospheric pressure that may reduce the frequency
and/or duration of apneas, hypopneas, and/or flow limitations. This
therapy may be delivered by using a positive airway pressure device
(PAP device) to propel a pressurized stream of air through a
conduit to a patient through an interface or mask located on the
face of the patient. The stream of air may be heated to near body
temperature. The stream of air may be humidified. The
humidification may be performed by forcing the stream of air to
travel through a respiratory humidifier containing water and a
heater for heating the water. In such a system the heater
encourages the evaporation of the water, which in turn partially or
fully imbues the stream of air with moisture and/or heat. This
moisture and/or heat may help to ameliorate discomfort that may
arise from the use of unhumidified PAP therapy.
[0005] In respiratory therapy methods involving administration of
pressurized respiratory gases to treat obstructive sleep apnea, it
is known to use constant positive airway pressure therapy, in which
the pressure delivered over the course of a therapy session remains
constant. An example of such a therapy is shown in FIG. 2 as a
pressure (P) versus time (T) graph. In some situations, bi-level
PAP therapy (also known as BiPAP therapy) may be used to treat OSA.
Bi-level PAP therapy may refer to a PAP therapy in which a PAP
device may be used to deliver a first pressure at or around a
detection of an inhalation of a patient (e.g., an inhalation
positive airway pressure or IPAP) and deliver a second pressure at
or around a detection of an exhalation of the patient (e.g., an
exhalation positive airway pressure or EPAP). To provide patient
comfort, the second pressure may be lower than the first pressure.
In some situations, the PAP device may reduce the pressure
delivered from a therapeutic level to a sub-therapeutic level upon
determination of a wakeful state of the patient and increase the
pressure delivered from a sub-therapeutic level to a therapeutic
level upon determination of an asleep state of the patient. In some
situations, it is desirable to configure a PAP device in such a way
that the pressure delivered is automatically adjusted over the
course of a therapy session to match the needs of the patient. It
is believed that utilizing high pressures only when the patient
requires high pressure therapy for a respiratory disorder can
improve the comfort of the therapy. Accordingly, an automatically
adjusting PAP device (AutoPAP device) capable of adjusting the
delivered pressure in such a way that the delivered pressure may
increase or decrease upon the detection of the presence or absence
of symptoms of a respiratory disorder may be provided. An example
of AutoPAP therapy is shown in FIG. 3 as a pressure versus time
graph. As can be seen, the AutoPAP device may initially start the
patient at a predetermined pressure (for example, P.sub.min as
shown in FIG. 1) and increase the delivered pressure upon detection
of a symptom of a respiratory disorder (for example, as shown at
point a or point c in FIG. 3). The AutoPAP device may also decrease
the delivered pressure upon detection of the absence of symptoms of
a respiratory disorder for a period of time (for example, as shown
at point d of FIG. 3). In such an AutoPAP device, in at least one
mode the range of pressures that the device may deliver may be
bounded by a minimum pressure level defining the lowest pressure
deliverable by the device and a maximum pressure level defining the
highest pressure deliverable by the device. In many cases, the
minimum and/or maximum pressures are prescribed by a medical
professional, and the device is likewise configured by the
professional or a medical device dealer.
SUMMARY
[0006] In many cases, when a physician wishes to prescribe AutoPAP
therapy for a patient with obstructive sleep apnea or another
condition treatable with PAP therapy, there is some difficulty in
deciding on the correct pressure range for the AutoPAP device. If
the pressure range selected is too large, for example 4 cm H.sub.2O
to 18 cm H.sub.2O, the minimum pressure of the range (e.g., 4 cm
H.sub.2O) may be too low to be therapeutically effective, and the
maximum pressure of the range (e.g., 18 cm H.sub.2O) may be greater
than required for maximal therapeutic benefit and/or too high for
optimal patient comfort. If the pressure range selected is too
small, for example 10 cm H.sub.2O to 12 cm H.sub.2O, the pressures
administered over the entire range may be too high for comfort or
too low to be effective, and/or the device may have a limited
ability to compensate for the onset of respiratory disorder
symptoms. Faced with such a problem, it is possible that the
physician may initially prescribe AutoPAP therapy with a large
pressure range, and have the patient use an AutoPAP device with
this pressure range for a trial period, e.g., one week. During use,
the AutoPAP device may record the pressures delivered by the device
during the trial period and the physician may, for example, examine
the recorded data during a subsequent visit with the patient. The
physician may then use his/her judgment to set an appropriate range
of pressures for the patient based on the data available.
[0007] In such a scenario, the physician spends additional time
with the patient and/or the patient's records, inconveniencing the
physician and increasing the burden on public and/or private
healthcare systems. Accordingly, it is an object of the disclosure
to provide an improved PAP system that might solve one or more of
the above problems, or at least provide the public with a useful
choice.
[0008] Thus, in accordance with at least one of the embodiments
disclosed herein, a respiratory therapy system is disclosed. The
respiratory therapy system is configured to adjust the operational
pressure range of the system based on sensed information about the
treatment of the patient as described herein. The respiratory
therapy system may comprise a flow generator. The respiratory
therapy system may comprise a sensor. The sensor may be adapted to
measure at least one characteristic capable of being used to
determine one or more traits of a sleep-disordered breathing event
(SDBE) of the patient. The respiratory therapy system may comprise
a controller. The controller may be configured to receive the at
least one characteristic measured by the sensor. The controller may
be configured to analyze the at least one characteristic. The at
least one characteristic may be analyzed to determine one or more
traits of an SDBE of the patient. The controller may control the
flow generator to maintain or adjust a pressure delivered by the
flow generator between a minimum and a maximum pressure, inclusive.
The maintaining or adjusting may be at least in part based on the
determined one or more traits of an SDBE. The minimum and/or
maximum pressures may be adjusted in response to one or more
parameters recorded during the course of the current therapy
session and/or one or more previous or past therapy sessions. The
parameters may include at least one of the following: the pressure
delivered and the one or more traits of the SDBE. In some
configurations, the controller may control the flow generator to
maintain or adjust the pressure delivered by the flow generator
between a minimum and a maximum pressure, inclusive, on an
event-by-event basis. In other words, the controller may react to
individual SDBEs as they are detected. In some configurations, the
controller may make the decision to change or not change the
minimum and/or maximum pressures on a session-by-session basis, a
time period-by-time period basis, a night-by-night basis, or on
some other basis.
[0009] In some configurations, the characteristics capable of being
used to determine the one or more traits of an SDBE may include one
or more of the following: gas pressure (e.g. delivered gas
pressure), gas flow (e.g. delivered gas flow), sound, flow
generator current (e.g. flow generator motor driving current), flow
generator speed (e.g. flow generator motor speed), flow generator
motor torque, motion (e.g. patient motion), tidal volume, heart
rate, lung volume, electroencephalograph signal, EEG signal,
EKG/ECG signal, breath composition, blood oxygen concentration, and
blood CO2 concentration. The traits of an SDBE may include one or
more of the following: the presence of an SDBE, the absence of an
SDBE, the type of SDBE, the severity of SDBE, the length of the
SDBE, and the latency of the SDBE.
[0010] The minimum pressure and/or maximum pressure may be adjusted
in response to the pressure delivered during the course of the
present therapy session. The minimum pressure and/or maximum
pressure may be adjusted in response to the pressure(s) delivered
during the course of one or more previous therapy sessions. The
minimum pressure and/or maximum pressure may be adjusted in
response to both the pressure delivered during the course of the
present therapy session and the pressure(s) delivered over the
course of one or more previous therapy sessions. In some
configurations, the delivered pressure at which the patient spent a
percentage of time at or below over the course of one or more
previous therapy sessions may be recorded. The minimum and/or
maximum pressures may be adjusted to a function of the recorded
pressure.
[0011] In some configurations, if the patient spends a percentage
of time at the maximum pressure greater than or equal to a first or
threshold percentage of time at the maximum pressure over the
course of one or more previous therapy sessions, the maximum
pressure may be increased. The threshold percentage of time may be
predetermined. In some configurations, if the patient spends a
percentage of time at the maximum pressure less than or equal to a
threshold percentage of time at the maximum pressure over the
course of one or more previous therapy sessions, the maximum
pressure may be decreased. The threshold percentage of time may be
predetermined. In some configurations, if the patient experiences a
number of pressure increases at or near the minimum pressure that
is greater than or equal to a predetermined number over a
predetermined period of time, the minimum pressure may be
increased.
[0012] Additionally, in accordance with at least one of the
embodiments disclosed herein, a method for delivering a respiratory
therapy is disclosed. A pressurized gas may be delivered to a
patient. At least one characteristic capable of being used to
determine one or more traits of a sleep-disordered breathing event
(SDBE) may be measured. The at least one characteristic may be
analyzed to determine the one or more traits of a sleep-disordered
breathing event of the patient. The pressure of the pressurized gas
delivered to the patient may be maintained or adjusted between a
minimum pressure and a maximum pressure, inclusive. The pressure
may be maintained or adjusted at least in part based on the
determined one or more traits of an SDBE. The minimum and/or
maximum pressures may be adjusted in response to one or more
parameters recorded during the course of the current therapy
session and/or one or more previous or past therapy sessions. The
parameters may include at least one of the following: the pressure
delivered and the one or more traits of the SDBE. In some
configurations, the decision to maintain or adjust the pressure
delivered between a minimum and a maximum pressure, inclusive, may
be made on an event-by-event basis. In other words, a decision may
be made to react to individual SDBEs as they are detected. In some
configurations, a decision may be made to change or not change the
minimum and/or maximum pressures on an (SDBE) event-by-event basis,
a session-by-session basis, a time period-by-time period basis, a
night-by-night basis, or on some other basis.
[0013] In some configurations, the characteristics capable of being
used to determine the one or more traits of an SDBE may include one
or more of the following: gas pressure (e.g. delivered gas
pressure), gas flow (e.g. delivered gas flow), sound, flow
generator current (e.g. flow generator motor driving current), flow
generator speed (e.g. flow generator motor speed), flow generator
motor torque, motion (e.g. patient motion), tidal volume, heart
rate, lung volume, EEG signal, EKG/ECG signal, breath composition,
blood oxygen concentration, and blood CO.sub.2 concentration. The
traits of an SDBE may include one or more of the following: the
presence of an SDBE, the absence of an SDBE, the type of SDBE, the
severity of SDBE, the length of the SDBE, and the latency of the
SDBE.
[0014] The minimum pressure and/or maximum pressure may be adjusted
in response to the pressure delivered during the course of the
present therapy session. The minimum pressure and/or maximum
pressure may be adjusted in response to the pressure(s) delivered
during the course of one or more previous therapy sessions. The
minimum pressure and/or maximum pressure may be adjusted in
response to both the pressure delivered during the course of the
present therapy session and the pressure(s) delivered over the
course of one or more previous therapy sessions. In some
configurations, the delivered pressure which the patient spent a
percentage of time at or below over the course of one or more
previous therapy sessions may be recorded. The minimum and/or
maximum pressures may be adjusted to a function of the recorded
pressure.
[0015] In some configurations, if the patient spends a percentage
of time at the maximum pressure greater than or equal to a first or
threshold percentage of time at the maximum pressure over the
course of one or more previous therapy sessions, the maximum
pressure may be increased. The threshold percentage of time may be
predetermined. In some configurations, if the patient spends a
percentage of time at the maximum pressure less than or equal to a
threshold percentage of time at the maximum pressure over the
course of one or more previous therapy sessions, the maximum
pressure may be decreased. The percentage of time may be
predetermined. In some configurations, if the patient experiences a
number of pressure increases at or near the minimum pressure that
is greater than or equal to a predetermined number over a
predetermined period of time, the minimum pressure may be
increased.
[0016] In accordance with at least some configurations disclosed
herein is a method of delivering a respiratory therapy comprising:
delivering a pressurized gas to a patient with a flow generator,
measuring with a sensor at least one characteristic capable of
being used to determine one or more traits of a sleep-disordered
breathing event (SDBE) of the patient, determining with a hardware
controller the one or more traits of the SDBE of the patient by
analyzing the at least one characteristic, repeatedly adjusting a
pressure window comprising a minimum pressure limit and a maximum
pressure limit in response to one or more parameters measured
during the course of the current therapy session and/or one or more
previous therapy sessions, the one or more parameters including at
least pressure delivered or the determined one or more traits of
the SDBE; and controlling the flow generator to deliver pressurized
gases, the pressure of the pressurized gases being at least in part
based on the determined one or more traits of the SDBE, and the
pressure of the pressurized gases being greater than or equal to
the minimum pressure limit and less than or equal to the maximum
pressure limit, wherein the minimum pressure limit is less than the
maximum pressure limit.
[0017] In some configurations the characteristics capable of being
used to determine the one or more traits of the SDBE include one or
more of the following: gas pressure, gas flow, sound, flow
generator current, flow generator speed, flow generator motor
torque, motion, tidal volume, heart rate, lung volume, EEG signal,
breath composition, blood oxygen concentration, and blood CO.sub.2
concentration.
[0018] In some configurations the traits of the SDBE include one or
more of the following: presence of the SDBE, absence of the SDBE,
type of SDBE, severity of the SDBE, length of the SDBE, and latency
of the SDBE.
[0019] In some configurations a decision may be made to maintain or
adjust the pressure delivered between the minimum pressure limit
and the maximum pressure limit, inclusive, on an event-by-event
basis.
[0020] In some configurations the therapy sessions comprise only
the current therapy session.
[0021] In some configurations the therapy sessions comprise only
one or more previous therapy sessions.
[0022] In some configurations the therapy sessions comprise both
the current therapy session and one or more previous therapy
sessions.
[0023] In some configurations the minimum pressure limit or the
maximum pressure limit is adjusted in response to the pressure
delivered during the course of the current therapy session and/or
one or more previous therapy sessions.
[0024] In some configurations the minimum pressure limit or the
maximum pressure limit is adjusted in response to the pressure
delivered during one or more previous therapy sessions.
[0025] In some configurations the delivered pressure at which the
patient spent a percentage of time at or below over the course of
one or more previous therapy sessions is recorded, and the minimum
pressure limit or the maximum pressure limit is adjusted to a
function of the recorded pressure.
[0026] In some configurations if the patient spends a time at the
maximum pressure limit that is greater than or equal to a threshold
percentage of time at the maximum pressure limit over the course of
one or more previous therapy sessions, the maximum pressure limit
is increased.
[0027] In some configurations if the patient spends a time at the
maximum pressure limit that is less than or equal to a threshold
percentage of time at the maximum pressure limit over the course of
one or more previous therapy sessions, the maximum pressure limit
is decreased.
[0028] In some configurations if the patient experiences a number
of delivered pressure increases greater than a predetermined number
over a predetermined period of time at or near the minimum pressure
limit, the minimum pressure limit is increased.
[0029] In some configurations the respiratory therapy comprises
automatic positive airway pressure therapy.
[0030] In some configurations the minimum pressure limit or the
maximum pressure limit is adjusted during a therapy session.
[0031] In some configurations both the minimum pressure limit and
the maximum pressure limit are adjusted during the therapy
session.
[0032] In accordance with at least some configurations disclosed
herein is a non-transitory computer readable medium configured to
store executable instructions for a method of delivering a
respiratory therapy, the executable instructions comprising:
controlling a flow generator to deliver a pressurized gas to a
patient, receiving from a sensor measurements of at least one
characteristic capable of being used to determine one or more
traits of a sleep-disordered breathing event (SDBE) of the patient,
determining with a hardware controller the one or more traits of
the SDBE of the patient by analyzing the at least one
characteristic, repeatedly adjusting a pressure window comprising a
minimum pressure limit and a maximum pressure limit in response to
one or more parameters measured during the course of the current
therapy session and/or one or more previous therapy sessions, the
one or more parameters including at least pressure delivered or the
determined one or more traits of the SDBE; and controlling the flow
generator to deliver pressurized gases, the pressure of the
pressurized gases being at least in part based on the determined
one or more traits of the SDBE, and the pressure of the pressurized
gases being greater than or equal to the minimum pressure limit and
less than or equal to the maximum pressure limit, wherein the
minimum pressure limit is less than the maximum pressure limit.
[0033] In some configurations the characteristics capable of being
used to determine the one or more traits of the SDBE include one or
more of the following: gas pressure, gas flow, sound, flow
generator current, flow generator speed, flow generator motor
torque, motion, tidal volume, heart rate, lung volume, EEG signal,
breath composition, blood oxygen concentration, and blood CO2
concentration.
[0034] In some configurations the traits of the SDBE include one or
more of the following: presence of the SDBE, absence of the SDBE,
type of SDBE, severity of the SDBE, length of the SDBE, and latency
of the SDBE.
[0035] In some configurations a decision may be made to maintain or
adjust the pressure delivered between the minimum pressure limit
and the maximum pressure limit, inclusive, on an event-by-event
basis.
[0036] In some configurations the therapy sessions comprise only
the current therapy session.
[0037] In some configurations the therapy sessions comprise only
one or more previous therapy sessions.
[0038] In some configurations the therapy sessions comprise both
the current therapy session and one or more previous therapy
sessions.
[0039] In some configurations the minimum pressure limit or the
maximum pressure limit is adjusted in response to the pressure
delivered during the course of the current therapy session and/or
one or more previous therapy sessions.
[0040] In some configurations the minimum pressure limit or the
maximum pressure limit is adjusted in response to the pressure
delivered during one or more previous therapy sessions.
[0041] In some configurations the delivered pressure at which the
patient spent a percentage of time at or below over the course of
one or more previous therapy sessions is recorded, and the minimum
pressure limit or the maximum pressure limit is adjusted to a
function of the recorded pressure.
[0042] In some configurations if the patient spends a time at the
maximum pressure limit that is greater than or equal to a threshold
percentage of time at the maximum pressure limit over the course of
one or more previous therapy sessions, the maximum pressure limit
is increased.
[0043] In some configurations if the patient spends a time at the
maximum pressure limit that is less than or equal to a threshold
percentage of time at the maximum pressure limit over the course of
one or more previous therapy sessions, the maximum pressure limit
is decreased.
[0044] In some configurations if the patient experiences a number
of delivered pressure increases greater than a predetermined number
over a predetermined period of time at or near the minimum pressure
limit, the minimum pressure limit is increased.
[0045] In some configurations the respiratory therapy comprises
automatic positive airway pressure therapy.
[0046] In some configurations the minimum pressure limit or the
maximum pressure limit is adjusted during a therapy session.
[0047] In some configurations both the minimum pressure limit and
the maximum pressure limit are adjusted during the therapy
session.
[0048] In accordance with at least some configurations disclosed
herein is a respiratory therapy system comprising: a flow generator
adapted to provide pressurized gases to a patient, a sensor adapted
to measure at least one characteristic capable of being used to
determine one or more traits of a sleep-disordered breathing event
(SDBE) of the patient, and a hardware controller configured to:
receive the at least one characteristic measured by the sensor,
determine the one or more traits of the SDBE of the patient by
analyzing the at least one characteristic, adjust a pressure window
for a first therapy session, the pressure window comprising a
minimum pressure limit and a maximum pressure limit, wherein the
hardware controller adjusts the pressure window in response to one
or more parameters measured during the course of one or more second
therapy sessions, the one or more parameters including at least the
determined one or more traits of the SDBE; and control the flow
generator to deliver pressurized gases, the pressure of the
pressurized gases being at least in part based on the determined
one or more traits of the SDBE, and the pressure of the pressurized
gases being greater than or equal to the minimum pressure limit and
less than or equal to the maximum pressure limit, wherein the
minimum pressure limit is less than the maximum pressure limit.
[0049] In some configurations the characteristics capable of being
used to determine the one or more traits of the SDBE include one or
more of the following: gas pressure, gas flow, sound, flow
generator current, flow generator speed, flow generator motor
torque, motion, tidal volume, heart rate, lung volume, EEG signal,
breath composition, blood oxygen concentration, and blood CO2
concentration.
[0050] In some configurations the first therapy session is a
current therapy session.
[0051] In some configurations the first therapy session is a future
therapy session.
[0052] In some configurations the one or more second therapy
sessions are past therapy sessions, wherein the one or more
parameters measured during the course of one or more second therapy
sessions comprises historical data measured for the patient.
[0053] In accordance with at least some configurations disclosed
herein is a method of providing respiratory therapy, the method
comprising: delivering pressurized gases to a patient using a flow
generator; measuring with a sensor at least one characteristic
capable of being used to determine one or more traits of a
sleep-disordered breathing event (SDBE) of the patient; determining
the one or more traits of the SDBE of the patient by analyzing the
at least one characteristic; adjusting a pressure window for a
first therapy session, the pressure window comprising a minimum
pressure limit and a maximum pressure limit, wherein the hardware
controller adjusts the pressure window in response to one or more
parameters measured during the course of one or more second therapy
sessions, the one or more parameters including at least the
determined one or more traits of the SDBE; and controlling the flow
generator to deliver pressurized gases, the pressure of the
pressurized gases being at least in part based on the determined
one or more traits of the SDBE, and the pressure of the pressurized
gases being greater than or equal to the minimum pressure limit and
less than or equal to the maximum pressure limit, wherein the
minimum pressure limit is less than the maximum pressure limit.
[0054] In some configurations the characteristics capable of being
used to determine the one or more traits of the SDBE include one or
more of the following: gas pressure, gas flow, sound, flow
generator current, flow generator speed, flow generator motor
torque, motion, tidal volume, heart rate, lung volume, EEG signal,
breath composition, blood oxygen concentration, and blood CO2
concentration.
[0055] In some configurations the first therapy session is a
current therapy session.
[0056] In some configurations the first therapy session is a future
therapy session.
[0057] In some configurations the one or more second therapy
sessions are past therapy sessions, wherein the one or more
parameters measured during the course of one or more second therapy
sessions comprises historical data measured for the patient.
[0058] In accordance with at least some configurations disclosed
herein is a non-transitory computer readable medium configured to
store executable instructions for a method of delivering a
respiratory therapy, the executable instructions comprising:
delivering pressurized gases to a patient using a flow generator;
measuring with a sensor at least one characteristic capable of
being used to determine one or more traits of a sleep-disordered
breathing event (SDBE) of the patient; determining the one or more
traits of the SDBE of the patient by analyzing the at least one
characteristic, adjusting a pressure window for a first therapy
session, the pressure window comprising a minimum pressure limit
and a maximum pressure limit, wherein the hardware controller
adjusts the pressure window in response to one or more parameters
measured during the course of one or more second therapy sessions,
the one or more parameters including at least the determined one or
more traits of the SDBE; and controlling the flow generator to
deliver pressurized gases, the pressure of the pressurized gases
being at least in part based on the determined one or more traits
of the SDBE, and the pressure of the pressurized gases being
greater than or equal to the minimum pressure limit and less than
or equal to the maximum pressure limit, wherein the minimum
pressure limit is less than the maximum pressure limit.
[0059] In some configurations the characteristics capable of being
used to determine the one or more traits of the SDBE include one or
more of the following: gas pressure, gas flow, sound, flow
generator current, flow generator speed, flow generator motor
torque, motion, tidal volume, heart rate, lung volume, EEG signal,
breath composition, blood oxygen concentration, and blood CO2
concentration.
[0060] In some configurations the first therapy session is a
current therapy session.
[0061] In some configurations the first therapy session is a future
therapy session.
[0062] In some configurations the one or more second therapy
sessions are past therapy sessions, wherein the one or more
parameters measured during the course of one or more second therapy
sessions comprises historical data measured for the patient.
[0063] In accordance with at least some configurations disclosed
herein is a respiratory therapy system comprising: a flow generator
adapted to provide pressurized gases to a patient, a sensor adapted
to measure at least one characteristic capable of being used to
determine one or more traits of a sleep-disordered breathing event
(SDBE) of the patient, and a hardware controller configured to:
receive the at least one characteristic measured by the sensor,
determine the one or more traits of the SDBE of the patient by
analyzing the at least one characteristic, repeatedly adjust a
pressure window for a first therapy session, the pressure window
comprising a minimum pressure limit and a maximum pressure limit,
wherein the hardware controller adjusts the pressure window in
response to one or more parameters measured during the course of
one or more second therapy sessions, the one or more parameters
including pressure delivered to the patient; and control the flow
generator to deliver pressurized gases, the pressure of the
pressurized gases being at least in part based on the determined
one or more traits of the SDBE, and the pressure of the pressurized
gases being greater than or equal to the minimum pressure limit and
less than or equal to the maximum pressure limit, wherein the
minimum pressure limit is less than the maximum pressure limit.
[0064] In some configurations the first therapy session is a
current therapy session.
[0065] In some configurations the first therapy session is a future
therapy session.
[0066] In some configurations the one or more second therapy
sessions are previous therapy sessions, wherein the one or more
parameters measured during the course of one or more second therapy
sessions comprises historical data measured for the patient.
[0067] In some configurations the minimum pressure limit or the
maximum pressure limit is adjusted in response to the pressure
delivered during the one or more previous therapy sessions.
[0068] In some configurations the delivered pressure at which the
patient spent a percentage of time at or below over the course of
one or more previous therapy sessions is recorded, and the minimum
pressure limit or the maximum pressure limit is adjusted to a
function of the recorded pressure.
[0069] In some configurations if the patient spends a time at the
maximum pressure limit that is greater than or equal to a threshold
percentage of time at the maximum pressure limit over the course of
one or more previous therapy sessions, the maximum pressure limit
is increased.
[0070] In some configurations if the patient spends a time at the
maximum pressure limit that is less than or equal to a threshold
percentage of time at the maximum pressure limit over the course of
one or more previous therapy sessions, the maximum pressure limit
is decreased.
[0071] In some configurations if the patient experiences a number
of delivered pressure increases greater than a predetermined number
over a predetermined period of time at or near the minimum pressure
limit, the minimum pressure limit is increased.
[0072] In accordance with at least some configurations disclosed
herein is a method for providing respiratory therapy to a patient,
the method comprising: delivering pressurized gases to a patient
using a flow generator; measuring with a sensor at least one
characteristic capable of being used to determine one or more
traits of a sleep-disordered breathing event (SDBE) of the patient;
determining the one or more traits of the SDBE of the patient by
analyzing the at least one characteristic; repeatedly adjusting a
pressure window for a first therapy session, the pressure window
comprising a minimum pressure limit and a maximum pressure limit,
wherein the hardware controller adjusts the pressure window in
response to one or more parameters measured during the course of
one or more second therapy sessions, the one or more parameters
including pressure delivered to the patient; and controlling the
flow generator to deliver pressurized gases, the pressure of the
pressurized gases being at least in part based on the determined
one or more traits of the SDBE, and the pressure of the pressurized
gases being greater than or equal to the minimum pressure limit and
less than or equal to the maximum pressure limit, wherein the
minimum pressure limit is less than the maximum pressure limit.
[0073] In some configurations the first therapy session is a
current therapy session.
[0074] In some configurations the first therapy session is a future
therapy session.
[0075] In some configurations the one or more second therapy
sessions are previous therapy sessions, wherein the one or more
parameters measured during the course of one or more second therapy
sessions comprises historical data measured for the patient.
[0076] In some configurations the one or more second therapy
sessions are previous therapy sessions, wherein the one or more
parameters measured during the course of one or more second therapy
sessions comprises historical data measured for the patient.
[0077] In some configurations the minimum pressure limit or the
maximum pressure limit is adjusted in response to the pressure
delivered during the one or more previous therapy sessions.
[0078] In some configurations the delivered pressure at which the
patient spent a percentage of time at or below over the course of
one or more previous therapy sessions is recorded, and the minimum
pressure limit or the maximum pressure limit is adjusted to a
function of the recorded pressure.
[0079] In some configurations if the patient spends a time at the
maximum pressure limit that is greater than or equal to a threshold
percentage of time at the maximum pressure limit over the course of
one or more previous therapy sessions, the maximum pressure limit
is increased.
[0080] In some configurations if the patient spends a time at the
maximum pressure limit that is less than or equal to a threshold
percentage of time at the maximum pressure limit over the course of
one or more previous therapy sessions, the maximum pressure limit
is decreased.
[0081] In some configurations if the patient experiences a number
of delivered pressure increases greater than a predetermined number
over a predetermined period of time at or near the minimum pressure
limit, the minimum pressure limit is increased.
[0082] In accordance with at least some configurations disclosed
herein is a non-transitory computer readable medium configured to
store executable instructions for a method of delivering a
respiratory therapy, the executable instructions comprising:
delivering pressurized gases to a patient using a flow generator;
measuring with a sensor at least one characteristic capable of
being used to determine one or more traits of a sleep-disordered
breathing event (SDBE) of the patient; determining the one or more
traits of the SDBE of the patient by analyzing the at least one
characteristic; repeatedly adjusting a pressure window for a first
therapy session, the pressure window comprising a minimum pressure
limit and a maximum pressure limit, wherein the hardware controller
adjusts the pressure window in response to one or more parameters
measured during the course of one or more second therapy sessions,
the one or more parameters including pressure delivered to the
patient; and controlling the flow generator to deliver pressurized
gases, the pressure of the pressurized gases being at least in part
based on the determined one or more traits of the SDBE, and the
pressure of the pressurized gases being greater than or equal to
the minimum pressure limit and less than or equal to the maximum
pressure limit, wherein the minimum pressure limit is less than the
maximum pressure limit.
[0083] In some configurations the first therapy session is a
current therapy session.
[0084] In some configurations the first therapy session is a future
therapy session.
[0085] In some configurations the one or more second therapy
sessions are previous therapy sessions, wherein the one or more
parameters measured during the course of one or more second therapy
sessions comprises historical data measured for the patient.
[0086] In some configurations the one or more second therapy
sessions are previous therapy sessions, wherein the one or more
parameters measured during the course of one or more second therapy
sessions comprises historical data measured for the patient.
[0087] In some configurations the minimum pressure limit or the
maximum pressure limit is adjusted in response to the pressure
delivered during the one or more previous therapy sessions.
[0088] In some configurations the delivered pressure at which the
patient spent a percentage of time at or below over the course of
one or more previous therapy sessions is recorded, and the minimum
pressure limit or the maximum pressure limit is adjusted to a
function of the recorded pressure.
[0089] In some configurations the patient spends a time at the
maximum pressure limit that is greater than or equal to a threshold
percentage of time at the maximum pressure limit over the course of
one or more previous therapy sessions, the maximum pressure limit
is increased.
[0090] In some configurations if the patient spends a time at the
maximum pressure limit that is less than or equal to a threshold
percentage of time at the maximum pressure limit over the course of
one or more previous therapy sessions, the maximum pressure limit
is decreased.
[0091] In some configurations if the patient experiences a number
of delivered pressure increases greater than a predetermined number
over a predetermined period of time at or near the minimum pressure
limit, the minimum pressure limit is increased.
[0092] In accordance with at least some configurations disclosed
herein is a respiratory therapy system comprising: a flow generator
adapted to provide pressurized gases to a patient, a sensor adapted
to measure at least one characteristic capable of being used to
determine one or more traits of a sleep-disordered breathing event
(SDBE) of the patient, and a hardware controller configured to: in
a first therapy mode, control the flow generator to deliver
pressurized gases at a first pressure level for a first time period
and to deliver pressurized gases at a second pressure level for a
second time period; determine for each of the first time period and
the second time period a sleep index based on one or more traits of
the SDBE of the patient by analyzing the at least one
characteristic; and determine a pressure window of a second therapy
mode, the pressure window comprising a minimum pressure limit and a
maximum pressure limit, wherein the hardware controller determines
the pressure window by using a continuous function that associates
a sleep index with a pressure level and by using the continuous
function to determine a tailored pressure level that achieves a
targeted sleep index; and defining the minimum pressure limit and
the maximum pressure limit of the pressure window based on the
tailored pressure level; wherein the minimum pressure limit is less
than the maximum pressure limit.
[0093] In some configurations the targeted sleep index is an
optimization utilizing the continuous function.
[0094] In some configurations the targeted sleep index is a minimum
of the continuous function.
[0095] In some configurations the targeted sleep index is a maximum
of the continuous function.
[0096] In accordance with at least some configurations disclosed
herein is a method of providing respiratory therapy, the method
comprising: delivering pressurized gases to a patient using a flow
generator; measuring with a sensor at least one characteristic
capable of being used to determine one or more traits of a
sleep-disordered breathing event (SDBE) of the patient; in a first
therapy mode, controlling the flow generator to deliver pressurized
gases at a first pressure level for a first time period and to
deliver pressurized gases at a second pressure level for a second
time period; determining for each of the first time period and the
second time period a sleep index based on one or more traits of the
SDBE of the patient by analyzing the at least one characteristic;
determining a pressure window of a second therapy mode, the
pressure window comprising a minimum pressure limit and a maximum
pressure limit, wherein the hardware controller determines the
pressure window by using a continuous function that associates a
sleep index with a pressure level and by using the continuous
function to determine a tailored pressure level that achieves a
targeted sleep index; and defining the minimum pressure limit and
the maximum pressure limit of the pressure window based on the
tailored pressure level; wherein the minimum pressure limit is less
than the maximum pressure limit.
[0097] In some configurations the targeted sleep index is an
optimization utilizing the continuous function.
[0098] In some configurations the targeted sleep index is a minimum
of the continuous function.
[0099] In some configurations the targeted sleep index is a maximum
of the continuous function.
[0100] In accordance with at least some configurations disclosed
herein is a non-transitory computer readable medium configured to
store executable instructions for a method of delivering a
respiratory therapy, the executable instructions comprising:
delivering pressurized gases to a patient using a flow generator;
measuring with a sensor at least one characteristic capable of
being used to determine one or more traits of a sleep-disordered
breathing event (SDBE) of the patient; in a first therapy mode,
controlling the flow generator to deliver pressurized gases at a
first pressure level for a first time period and to deliver
pressurized gases at a second pressure level for a second time
period; determining for each of the first time period and the
second time period a sleep index based on one or more traits of the
SDBE of the patient by analyzing the at least one characteristic;
determining a pressure window of a second therapy mode, the
pressure window comprising a minimum pressure limit and a maximum
pressure limit, wherein the hardware controller determines the
pressure window by using a continuous function that associates a
sleep index with a pressure level and by using the continuous
function to determine a tailored pressure level that achieves a
targeted sleep index; and defining the minimum pressure limit and
the maximum pressure limit of the pressure window based on the
tailored pressure level; wherein the minimum pressure limit is less
than the maximum pressure limit.
[0101] In some configurations the targeted sleep index is an
optimization utilizing the continuous function.
[0102] In some configurations the targeted sleep index is a minimum
of the continuous function.
[0103] In some configurations the targeted sleep index is a maximum
of the continuous function.
BRIEF DESCRIPTION OF THE DRAWINGS
[0104] Specific embodiments and modifications thereof will become
apparent to those skilled in the art from the detailed description
herein having reference to the figures that follow, of which:
[0105] FIG. 1 shows a schematic diagram of a respiratory therapy
system.
[0106] FIG. 2 shows a pressure versus time graph demonstrating an
example of constant positive airway pressure therapy.
[0107] FIG. 3 shows a pressure versus time graph demonstrating an
example of automatic positive airway pressure (AutoPAP or APAP)
therapy.
[0108] FIG. 4 shows a pair of pressure versus time graphs
demonstrating an example of AutoPAP therapy wherein the minimum and
maximum pressures change as a function of the pressure administered
over the course of a therapy session.
[0109] FIG. 5 shows a pair of pressure versus time graphs
demonstrating an example of AutoPAP therapy wherein the maximum
pressure increases relative to the time spent delivering the
maximum pressure.
[0110] FIG. 6 shows a pair of pressure versus time graphs
demonstrating an example of AutoPAP therapy wherein the maximum
pressure decreases relative to the time spent delivering the
maximum pressure.
[0111] FIG. 7 shows a pair of pressure versus time graphs
demonstrating an example of AutoPAP therapy wherein the minimum
pressure increases as a function of the frequency of events
occurring at the minimum pressure.
[0112] FIGS. 8A-8D show a set of pressure versus time graphs
demonstrating several therapy sessions of constant PAP therapy,
wherein the pressure used for each of the several therapy sessions
is different.
[0113] FIG. 9 shows a method for selecting minimum and/or maximum
pressures for AutoPAP therapy based on a set of pressures used in
several sessions of constant PAP therapy.
[0114] FIG. 10 shows a relationship between constant PAP pressures
and AHI values.
[0115] FIG. 11 shows a flow chart of an example method for
adjusting a pressure range for respiratory therapy.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0116] Aspects of at least one of the configurations disclosed
herein includes the realization that an AutoPAP system can be
configured to not only automatically change the instant pressure
delivered to the patient during a therapy session, but additionally
to automatically change, at least in one mode of operation, the
minimum and/or maximum pressures deliverable by the AutoPAP
system.
[0117] With reference to FIG. 1, a configuration for a respiratory
therapy system 100 is shown. In the illustrated configuration, the
respiratory system 100 may comprise a flow generator 101. The flow
generator 101 may comprise a gas inlet 102 and a gas outlet 104.
The flow generator may comprise a blower 106. The blower 106 may
comprise a motor. The motor may comprise a stator and a rotor. The
rotor may comprise a shaft. An impeller may be linked to the shaft.
In use, the impeller may rotate concurrently with the shaft to draw
in gas from the gas inlet 102. The flow generator 101 may comprise
a user interface 108 which may comprise one or more buttons, knobs,
dials, switches, levers, touch screens, and/or displays so that a
user might view data related to the operation of the flow generator
101 or to other components of the respiratory therapy system 100 or
input operation parameters into the flow generator 101 to control
its operation or the operation of other aspects of the respiratory
therapy system 100. The flow generator 101 may pass gas through the
gas outlet 104 to a first conduit 110. The first conduit 110 may
pass the gas to a humidifier 112 that may entrain moisture in the
gas to provide a humidified gas stream. The humidifier 112 may
comprise a humidifier inlet 116 and a humidifier outlet 118. The
humidifier 112 may comprise a reservoir 114 that may be filled with
water or some other humidifying agent. The humidifier 112 may
comprise a heating element 113. The heating element 113 may be used
to heat the humidifying agent in the reservoir 114 to encourage
agent vaporization and/or entrainment in the gas flow and/or
increase the temperature of gases passing through the humidifier
112. The humidifier 112 may have a user interface 120 which may
comprise one or more buttons, knobs, dials, switches, levers, touch
screens, and/or displays so that a user might view data related to
the operation of the humidifier 112 or to other components of the
respiratory therapy system 100 or input operation parameters into
the humidifier 112 to control the operation of the heating element
113, operation of other aspects of the humidifier 112, and/or other
aspects of the respiratory therapy system 100. Gas may then pass
from the humidifier outlet 118 to a second conduit 122. The second
conduit 122 may comprise a heater. The heater may be used to add
heat to gases passing through the second conduit 122 in order to
prevent the condensation of moisture entrained in the gas stream
along the walls of the second conduit 122. The heater may comprise
one or more resistive wires located in, on, around or near the
walls of second conduit 122. Gas passing through the second conduit
122 may then enter a patient interface 124 that may pneumatically
link the respiratory therapy system 100 to the patient's airway.
The patient interface 124 may comprise a nasal mask, an oral mask,
an oro-nasal mask, a full face mask, a nasal pillows mask, a nasal
cannula, an endotracheal tube, a combination of the above or some
other gas conveying system. The flow generator 101, humidifier 112,
and/or other parts of the respiratory therapy system 100 may
comprise a controller (not shown). The controller may be a
microprocessor. The controller may help to control the operation of
the flow generator 101, humidifier 112, and/or other aspects or
operation parameters of the respiratory therapy system 100.
[0118] In the illustrated configuration, and as implied above, the
respiratory therapy system 100 may operate as follows: gas may be
drawn into the flow generator 101 through the gas inlet 102 due to
the rotation of an impeller of the motor of the blower 106. Gas may
then be propelled out of the gas outlet 104 and along the first
conduit 110. The gas flow may enter the humidifier 112 through the
humidifier inlet 116. Once in the humidifier 112, the gas may pick
up moisture while passing over the humidification agent in the
reservoir 114. The humidification agent in the reservoir 114 may be
heated by the heating element 113, which may aid in the
humidification and/or heating of the gas passing through the
humidifier 112. The gas may then leave the humidifier 112 through
the humidifier outlet 118 and enter the second conduit 122. Gas may
then be passed from the second conduit 122 to the patient interface
124, where it may be taken into the patient's airways to aid in the
treatment of respiratory disorders.
[0119] It should be understood that the illustrated configuration
should not be taken to be limiting, and that many other
configurations for the respiratory therapy system 100 are possible.
In some configurations, the flow generator 101 may, for example,
comprise a source or container of compressed air. The container may
comprise a valve that may be adjusted to control the flow of gas
leaving the container. In some configurations, the flow generator
101 may use such a source of compressed air or another gas source
in lieu of a blower 106. In some configurations the blower 106 may
be used in conjunction with another gas source. In some
configurations the flow generator 101 may draw in atmospheric gases
through the gas inlet 102. In some configurations the flow
generator 101 may be adapted to both draw in atmospheric gases
through the gas inlet 102 and accept other gases (e.g. oxygen,
nitric oxide, carbon dioxide, etc.) through the same inlet 102 or a
different inlet. In some configurations the humidifier 112 can be
integrated with the flow generator 101. In some configurations the
humidifier 112 and the flow generator 101 may share a housing. In
some such configurations only a single conduit extending between
the flow generator 101 and the patient interface 124 need be used
to convey gases to a patient. In some configurations, the
humidifier 112 may not be present. In some such configurations, the
first conduit 110 and the second conduit 122 may be replaced with a
single conduit extending from the flow generator 101 to the patient
interface 124. In some configurations, the flow generator 101 and
the humidifier 112 may have a single user interface located on
either the flow generator 101 or the humidifier 112. In some
configurations, the operation of the flow generator 101, of the
humidifier 112, or of other aspects of the respiratory therapy
system 100 may be controlled a single controller. In some
configurations, the operation of the flow generator 101, of the
humidifier 112, or of other aspects of the respiratory therapy
system 100 may be controlled wirelessly using a user interface
located on a remote computing device. In some configurations, the
respiratory therapy system 100 may comprise one or more sensors for
detecting various characteristics of the gas, including pressure
and/or flow rate.
[0120] The respiratory therapy system 100 may comprise one or more
sensors capable of detecting one or more characteristics of the
patient, characteristics of the respiratory activity of the
patient, characteristics of the respiratory therapy system 100,
data related to the operation of the respiratory therapy system
100, and/or characteristics of gases moving through the respiratory
therapy system 100. The one or more sensors may include one or more
of the following: a pressure sensor, a flow sensor, a sound sensor,
a motor current transducer, a motor speed transducer, a motor
torque transducer, a heart rate sensor, a plethysmograph, an
electroencephalograph (EEG), an electrocardiograph (ECG), a motion
sensor, a breath composition sensor, a pulse oximeter, a blood
oxygen concentration sensor, and a blood CO2 concentration sensor.
The characteristics obtainable from the one or more sensors may
include one or more of the following: gas pressure, gas flow,
sound, flow generator motor current, flow generator motor speed,
flow generator motor torque, heart rate, tidal volume, lung volume,
EEG signal, ECG signal, movement, breath composition, blood oxygen
concentration, and blood CO2 concentration. The one or more sensors
may be physically part of the respiratory therapy system 100 or
wired to a part of the respiratory therapy system 100. In some
configurations, the one or more sensors may be remote from the
respiratory therapy system 100. The one or more sensors may be
capable of wireless communication with the respiratory therapy
system 100. Measurements obtained by the one or more sensors of the
respiratory therapy system 100 may be used to determine, for
example, a trait of a sleep-disordered breathing event (SDBE) of a
patient using the respiratory therapy system 100. A controller of
the respiratory therapy system 100, which may be, for example, a
microprocessor, may use the characteristics obtained by the one or
more sensors to determine a trait of the SDBE. The controller of
the respiratory therapy system 100 may be physically part of the
respiratory therapy system 100 or wired to a part of the
respiratory therapy system 100. In some configurations, the
controller may be remote from the respiratory therapy system 100,
e.g., on a remote server or a mobile device (e.g., a tablet or
cellular phone). The controller may be capable of wireless
communication with the respiratory therapy system 100. Determined
traits of the SDBE may include the presence, absence, type,
severity, and/or length of the SDBE. The type of an SDBE may
include one or more of the following: an apnea, a hypopnea, and a
flow limitation. The severity of an SDBE may be a numerical
indicator or may be a qualitative designation that may be applied
to a particular SDBE, e.g. `mild,` `moderate,` or `severe.` In some
cases, an SDBE may be predicted by the characteristics of the
respiratory flow preceding an SDBE. For example, in some cases, an
apnea event may be predicted by analysis of the flow waveform of
breaths preceding the apnea. One additional trait of an SDBE may be
the latency of the SDBE, which may be defined as a function of one
or more qualities of the respiratory activity of the patient
preceding the SDBE. The qualities may be one or more of a flow
waveform, a pressure waveform, motion of the patient, or some other
indicator of respiratory activity preceding an SDBE.
[0121] Attention is now given to use of a respiratory therapy
system 100 configured for use as an AutoPAP device. In such a
device, the respiratory therapy system 100 may comprise a
controller that, in at least one mode of operation, may define a
range of pressures. The range of pressures may be bounded by a
minimum pressure level defining the lowest pressure deliverable by
respiratory therapy system 100 and/or by a maximum pressure level
defining the highest pressure deliverable by the respiratory
therapy system 100. The minimum and/or maximum pressures may be the
pressures delivered to the patient or pressures taken at any point
of the respiratory therapy system 100. The minimum and maximum
pressures may be different pressures. The flow generator 101 may be
controlled such that the respiratory therapy system 100 may deliver
a pressure to the patient that is no less than the minimum pressure
level and no greater than the maximum pressure level. The AutoPAP
device may be configured to detect one or more traits of an SDBE
experienced by a patient during a therapy session and respond by
maintaining or adjusting the pressure delivered by the respiratory
therapy system 100 based on the traits to accommodate the therapy
and/or comfort needs of the patient. For example, upon detecting
that the patient is experiencing an episode of obstructive sleep
apnea, the respiratory therapy system 100 may increase the pressure
delivered to compensate for the apnea episode. Similarly, upon
detecting the absence of an SDBE for a period of time, the
respiratory therapy system 100 may decrease the pressure delivered
to improve the comfort of the therapy for the patient. In some
configurations, BiPAP therapy may be used in conjunction with
AutoPAP therapy. In some such configurations, the therapeutic
pressure (e.g. the instant pressure delivered during AutoPAP
therapy) may be the pressure used during patient inhalation, and
the pressure may be lowered upon patient exhalation. In some
configurations, the therapeutic pressure delivered may be the
pressure used during patient exhalation, and the pressure may be
increased upon patient inhalation. In some configurations, the EPAP
may not be less than the minimum pressure. In some configurations,
the IPAP may not be greater than the maximum pressure.
[0122] Several methods of automatically adjusting the minimum and
maximum pressures of an AutoPAP device are described herein. With
reference to FIG. 4, a pair of graphs showing pressure versus time
depict a method for adjusting the minimum and maximum pressures of
an AutoPAP device. On the left graph, a therapy session
(hereinafter referred to as the `current` therapy session) in which
AutoPAP therapy is used is shown. As can be observed, the session
may begin with the device delivering the minimum pressure (although
in some configurations, other starting pressures may be used), and
the pressure delivered may gradually increase and decrease as the
patient experiences apneas, hypopneas, or other SDBEs, or the
absence of SDBEs, or other conditions warranting a pressure
adjustment. The device may record data indicative of the pressures
delivered over the course of the current therapy session. In some
configurations, during or after the current therapy session, the
device may analyze the data recorded over the current therapy
session and/or the data recorded over one or more past therapy
sessions. The data recorded may be used to determine a target
pressure P.sub.t which the patient spent at least an amount of time
T at or under. In this example, the amount of time T is
predetermined to be at least 90% of the total time of the current
therapy session. However, the amount of time could be at least a
predetermined number of hours (e.g., 3 hours, 10 hours, 20 hours,
30 hours, etc.), another percentage of the therapy session (e.g.,
at least 95% of the total time, at least 85% of the total time, at
least 80% of the total time, at least 75% of the total time, etc.),
a percentage of one or more past therapy sessions (e.g., at least
95% of past therapy sessions, at least 85% of past therapy
sessions, at least 80% of past therapy sessions, at least 75% of
past therapy sessions, etc.), a variable amount of time determined
as a function of other variables of the current or past sessions of
use, or a combination of the above. In some configurations, the
device may determine a target pressure P.sub.t at or under which
the patient spent at least an amount of time T, where the time T
may be an average of times spent over the course of multiple
therapy sessions or periods of time. For example, the amount of
time T may be predetermined to be an average of at least 90% of the
total time of the current therapy session and the last two previous
sessions. In such an example, if all of the therapy sessions are 8
hours in length, and the patient spends 85% of the first previous
session at or under the target pressure P.sub.t, 90% of the second
previous session at or under the target pressure P.sub.t, and 95%
of the current session at or under the target pressure P.sub.t, the
average amount of time T which the patient spends at or under the
target pressure P.sub.t may be determined to be 90%. This target
pressure P.sub.t may be considered a pressure which is
therapeutically effective for the patient. The minimum and maximum
pressures may be adjusted to a function of the target pressure
P.sub.t. In some configurations, the minimum and/or maximum
pressures may be changed to the target pressure P.sub.t minus
and/or plus a pressure offset P.sub.o, respectively. The pressure
offset P.sub.o may be predetermined or may be a function of the
target pressure P.sub.t or of some other variable. In some
configurations, multiple pressure offsets may be used--for example,
a minimum pressure offset P.sub.o.sub._.sub.min may be used to
calculate the minimum pressure from the target pressure P.sub.t and
a maximum pressure offset P.sub.o.sub._.sub.max may be used to
calculate the maximum pressure from the target pressure P.sub.t. In
the illustrated example, the target pressure P.sub.t at which the
patient spent 90% of the therapy session at or under was calculated
to be 10 cm H.sub.2O. The pressure offset P.sub.o was predetermined
to be 2 cm H.sub.2O. Correspondingly, as can be seen on the right
graph, the minimum pressure has been changed to 8 cm H.sub.2O (10
cm H.sub.2O-2 cm H.sub.2O) and the maximum pressure has been
changed to 12 cm H.sub.2O (10 cm H.sub.2O+2 cm H.sub.2O). This new
pressure range (8 to 12 cm H.sub.2O) may be used for subsequent
therapy sessions, and may be more therapeutically effective for the
patient than the original pressure range (4 to 18 cm H.sub.2O)
while still allowing some improved flexibility and comfort over
traditional constant PAP therapy.
[0123] In some configurations, constant PAP therapy may be used for
several periods of time, and a target pressure P.sub.t may be
determined after analyzing data recorded during these periods of
time. A period of time may be a number of seconds, a number of
minutes, a number of hours, a number of days, a therapy session, a
number of therapy sessions, a percentage of a therapy session, or
some other quantity of time. In some such configurations, a PAP
device may be used (which may be the AutoPAP device or some other
PAP device) to administer constant PAP therapy over the course of
several periods of time. The individual time periods may be
successive or may be staggered (e.g., non-successive). The pressure
delivered during the individual time periods may be different such
that different measurements relating to the traits of SDBEs or
quality of sleep over the course of each individual time period may
be obtained. In some configurations, a sleep index S.sub.i may be
determined indicating some aspect of the SDBE traits determined
over the course of a time period. The sleep index S.sub.i may, for
example, be an apnea-hypopnea index (AHI), total apnea event count,
total hypopnea event count, total flow limitation event count, a
combination of some or all of the above, or some other value. In
some configurations, a sleep quality index SQ.sub.i may be
determined indicating a value derived from a function of one or
more sleep indices S.sub.i. The determined sleep quality index
SQ.sub.i may comprise a numeral indicator quantifying the perceived
sleep quality for a given time period. In some such configurations,
higher sleep quality indices SQ.sub.i indicate high sleep
qualities. The sleep index/indices Si and/or the sleep quality
index/indices SQ.sub.i obtained for each individual time period may
be compared with each other at the end of the several periods of
time. For example, the lowest sleep index Si and/or highest sleep
quality index SQ.sub.i among the set of sleep indices or sleep
quality indices SQ.sub.i found for the several periods of time may
be determined. The target pressure P.sub.t, minimum pressure and/or
maximum pressure may then be set to the CPAP pressure used during
the period of time at which the lowest sleep index S.sub.i and/or
highest sleep quality index SQ.sub.i was found, or a function of
the CPAP pressure used during this period of time. In some
configurations minimum and/or maximum pressures may be derived from
the target pressure P.sub.t, and AutoPAP therapy can be utilized
based on the therapy range established. This may be actuated by
using one or more offset pressures P.sub.o as described herein.
[0124] To demonstrate the above, attention is now given to FIGS.
8A-8D. In the illustrated configuration, the several time periods
may be several therapy sessions. In FIG. 8A, constant PAP therapy
at a pressure of 8 cm H.sub.2O is used for a first therapy session.
In FIG. 8B, constant PAP therapy at a pressure of 10 cm H.sub.2O is
used for a second therapy session. In FIG. 8C, constant PAP therapy
at a pressure of 12 cm H.sub.2O is used for a third therapy
session. In FIG. 8D, constant PAP therapy at a pressure of 14 cm
H.sub.2O is used for a fourth therapy session. An apnea-hypopnea
index (AHI) may be calculated for each individual therapy session
and a target pressure P.sub.o may be set to the CPAP pressure used
during the therapy session on which the lowest AHI was recorded. In
the illustrated configuration, an AHI of 30/hour was obtained for
the first therapy session, an AHI of 20/hour was obtained for the
second therapy session, an AHI of 7/hour was obtained for the third
therapy session, and an AHI of 5/hour was obtained for the fourth
therapy session. The AHI of 5/hour for the fourth therapy session
was the lowest AHI recorded over the course of the several therapy
sessions, and so the target pressure P.sub.t may be set to 14 cm
H.sub.2O. A pressure offset P.sub.o may be used to determine a
minimum pressure and/or a maximum pressure. For example, if the
pressure offset P.sub.o is predetermined to be 2 cm H2O, then the
minimum pressure may be set to (14 cm H.sub.2O-2 cm H.sub.2O) or 12
cm H.sub.2O and the maximum pressure may be set to (14 cm
H.sub.2O+2 cm H.sub.2O) or 16 cm H.sub.2O. For the fifth and/or
other future therapy sessions, instead of constant PAP therapy,
AutoPAP therapy may be used with a minimum pressure of 12 cm
H.sub.2O and a maximum pressure of 16 cm H.sub.2O. The minimum and
maximum ranges thereon may be changed through the use of other
methods identical or similar to those disclosed herein. In other
configurations a predetermined AHI value may be established and the
target pressure P.sub.o may be set to the lowest CPAP pressure for
which the calculated AHI was less than or equal to the
predetermined AHI value or a function of the lowest CPAP pressure.
In other configurations the minimum and/or maximum pressures may be
set to some other function of the target pressure P.sub.o.
[0125] In some configurations, the minimum and/or maximum pressures
may be selected based on a range of sleep indices S.sub.i and/or
sleep quality indices SQ.sub.i. With continued reference to FIGS.
8A-8D, constant PAP therapy may be used for several therapy
sessions, wherein a different constant PAP pressure may be used for
each individual therapy session. Similarly, sleep indices S.sub.i
and/or sleep quality indices SQ.sub.i may be calculated for each
individual therapy session. FIG. 9 demonstrates a pressure versus
sleep index S.sub.i function, although it should be understood that
a similar graph may be used to illustrate a pressure versus sleep
quality index SQ.sub.i function. As shown in FIG. 9, a relationship
between the sleep indices S.sub.i and/or sleep quality indices
SQ.sub.i and the CPAP pressures used may be found. The sleep
indices S.sub.i and/or sleep quality indices SQ.sub.i may be
plotted against the CPAP pressures used. A polynomial function may
be found describing the relationship between the sleep indices
S.sub.i and/or sleep quality indices SQ.sub.i and the CPAP
pressures used. In some configurations, a range of sleep indices Si
bounded by a minimum sleep index value S.sub.i.sub._.sub.min and a
maximum sleep index value S.sub.i.sub._.sub.max may be defined. The
range may be predetermined. The minimum sleep index value
S.sub.i.sub._.sub.min may designate a first predetermined sleep
index value where gas therapies resulting in sleep index values
under the first predetermined sleep index value are considered
sub-optimal. The maximum sleep index value S.sub.i.sub._.sub.max
may designate a second predetermined sleep index value where gas
therapies resulting in sleep index values over the second
predetermined sleep index value are considered sub-optimal. Minimum
and/or maximum pressures may be determined from analysis of the
polynomial function by determining a minimum pressure at which a
minimum sleep index S.sub.i.sub._.sub.min may be observed and/or a
maximum pressure at which a maximum sleep index
S.sub.i.sub._.sub.max may be observed. As an example, as seen in
FIGS. 8A-8D, four sessions of therapy may be recorded in which
different constant PAP pressures (in this case, 8 cm H.sub.2O for
the first session, 10 cm H.sub.2O for the second session, 12 cm
H.sub.2O for the third session, and 14 cm H.sub.2O for the fourth
session) are used and different AHI values (the sleep indices
S.sub.i in this case) may be obtained for each session (in this
case, AHI values of 30/hour for the first session, 20/hour for the
second session, 7/hour for the third session, and 5/hour for the
fourth session). As seen in FIG. 10, the relationship between the
constant PAP pressures used and the AHI values obtained may be
plotted. A polynomial function showing the AHI as a function of the
CPAP pressure used may be found, and the pressures corresponding to
the minimum AHI value and/or the maximum AHI value may be found. In
this example, and as demonstrated by FIGS. 8A-8D and FIG. 10, the
minimum AHI value was predetermined to be 5/hour and the maximum
AHI value was predetermined to be 7/hour. The pressures
corresponding to the minimum and maximum AHI values were found to
be 14 cm H.sub.2O and 12 cm H.sub.2O, respectively. In this
example, AutoPAP therapy may then be used, where 12 cm H.sub.2O may
be assigned as the minimum pressure and 14 cm H.sub.2O may be
assigned as the maximum pressure.
[0126] In some configurations, if the maximum pressure deliverable
is determined to be too low, the AutoPAP device may automatically
increase the maximum pressure. With reference to FIG. 5, a pair of
pressure versus time graphs depicting a method for adjusting the
maximum pressure for an AutoPAP device is shown. On the left graph,
a therapy session in which AutoPAP is used is shown. As can be
observed, the session may begin at the minimum pressure (but may
begin at some other pressure) and may increase to a higher pressure
upon detecting apneas, hypopneas, or other SDBEs. The pressure may
increase to the maximum pressure. After or over the course of a
monitoring period (which may be a number of hours, a portion of a
therapy session, an entire therapy session, multiple therapy
sessions, or some other period of time), the amount of time
T.sub.max.sub._.sub.total over which the device delivers the
maximum deliverable pressure may be calculated or monitored. If the
T.sub.max.sub._.sub.total is determined to be greater than or equal
to a threshold percentage T % of the monitoring period, the device
may increase the maximum deliverable pressure. The maximum pressure
may be adjusted, for example, immediately after the determination,
a period of time after the determination, or during a subsequent
therapy session. In the illustrated example, the
T.sub.max.sub._.sub.total (here, T.sub.1+T.sub.2+T.sub.3+T.sub.4)
was found to be 50% of the monitoring period, the T % was
predetermined to be 10% of the monitoring period, and the
monitoring period was predetermined to be an entire therapy
session. The T.sub.max.sub._.sub.total was determined to be greater
than the T %, and so the maximum pressure 18 cm H.sub.2O was
increased to 19 cm H.sub.2O. In some configurations, the maximum
pressure may increase by a predetermined amount, by a predetermined
amount up to a limit, by a function of the current maximum
pressure, by a function of the current minimum pressure, and/or by
a function of the number and/or intensity of previous maximum
and/or minimum pressure changes. In the illustrated example, the
new maximum pressure could be used in a subsequent therapy
session.
[0127] Similarly, in some configurations, if the maximum pressure
deliverable is determined to be too high, the AutoPAP device may
automatically decrease the maximum pressure. With reference to FIG.
6, a pair of pressure versus time graphs depicting a method for
adjusting the maximum pressure for an AutoPAP device is shown. On
the left graph, a therapy session in which AutoPAP is used is
shown. As can be observed, the session begins at the minimum
pressure and may increase to the pressure upon detecting apneas,
hypopneas, or other SDBEs. The pressure may increase to the maximum
pressure. After or over the course of a monitoring period (which
may be a number of hours, a portion of a therapy session, an entire
therapy session, multiple therapy sessions, or some other period of
time), the amount of time T.sub.max.sub._.sub.total over which the
device delivers the maximum deliverable pressure may be calculated
or monitored. If the T.sub.max.sub._.sub.total is determined to be
less than or equal to a threshold percentage T % of the monitoring
period, the device may decrease the maximum deliverable pressure.
The maximum pressure may be adjusted, for example, immediately
after the determination, a period of time after the determination,
or during a subsequent therapy session. In the illustrated example,
the T.sub.max.sub._.sub.total (here, T.sub.1+T.sub.2) was found to
be 4% of the monitoring period, the T % was predetermined to be 5%
of the monitoring period, and the monitoring period was
predetermined to be an entire therapy session. The
T.sub.max.sub._.sub.total was determined to be less than the T %,
and so the maximum pressure 18 cm H.sub.2O was decreased to 17 cm
H.sub.2O. In some configurations, the maximum pressure can decrease
by a predetermined amount, by a predetermined amount up to a limit,
by a function of the current maximum pressure, by a function of the
current minimum pressure, and/or by a function of the number and/or
intensity of previous maximum and/or minimum pressure changes. In
the illustrated example, the new maximum pressure could be used in
a subsequent therapy session.
[0128] In some configurations, if the minimum pressure deliverable
is determined to be too low, the AutoPAP device may automatically
increase the minimum pressure. With reference to FIG. 7, a pair of
pressure versus time graphs depicting a method for adjusting the
minimum pressure for an AutoPAP device is shown. On the left graph,
a therapy session in which AutoPAP is used is shown. As can be
observed, the session begins at the minimum pressure (but may begin
at some other pressure) and the pressure delivered gradually
increases and decreases as the patient experiences apneas,
hypopneas, or other SDBEs or the absence of SDBEs, or other
conditions warranting a pressure adjustment. If the device
determines that a significant number of pressure-increasing SDBEs
or other conditions warranting a pressure increase have occurred at
or near the minimum pressure, the minimum pressure may be
determined to be too low. For example, the device may define an
event count E.sub.c representing a number of pressure increases
occurring at or near (e.g., within 1 to 3 cm H2O) the minimum
pressure, an event count threshold E.sub.c.sub._.sub.t and a
predetermined time Tp. If the event count E.sub.c over a defined
time T.sub.p is greater than an event count threshold
E.sub.c.sub._.sub.t, the device may increase the minimum pressure.
In the illustrated example, the T.sub.p was defined to be 30
minutes, the E.sub.c was found to be 6 (see T1-T6 on left graph),
and the E.sub.c.sub._.sub.t was defined to be 5. The E.sub.c for
the time T.sub.p was determined to be greater than the
E.sub.c.sub._.sub.t, so the minimum pressure was raised from 4 cm
H.sub.2O to 5 cm H.sub.2O. Similarly, the minimum pressure may be
adjusted, for example, after the determination, a period of time
after the determination, or during a subsequent therapy session. In
some configurations, the minimum pressure can increase by a
predetermined amount, by a predetermined amount up to a limit, by a
function of the current maximum pressure, by a function of the
current minimum pressure, and/or by a function of the number and/or
intensity of previous maximum and/or minimum pressure changes. In
the illustrated configuration, the new minimum pressure may be used
in a subsequent therapy session.
[0129] FIG. 11 illustrates a flow chart of an example method 200
for adjusting a pressure range for respiratory therapy using an
AutoPAP device. The method can be implemented by the devices
described herein or by any other suitable AutoPAP device configured
to deliver automatically adjusting pressure during respiratory
therapy. The method 200 can be used to adjust minimum and/or
maximum pressures available to the AutoPAP device when providing
respiratory therapy. In some embodiments, the method 200 can be
implemented by one or more software and/or hardware components on
the AutoPAP device. For ease of description, then, the method 200
will be described as being performed by an AutoPAP device. However,
any other suitable configuration of modules, devices, apparatuses,
and systems comprising software and/or hardware can be used to
implement one or more steps of the method 200.
[0130] In block 205, the AutoPAP device delivers pressurized gas to
a patient, the pressurized gas having a pressure within an initial
pressure range. The minimum and/or maximum pressures can be, for
example and without limitation, set by a user, a physician, a
clinician, or the pressures can be default values of the AutoPAP
device. In some embodiments, the AutoPAP device limits the
potential values of the minimum and/or maximum pressures available
during respiratory therapy. For example, the AutoPAP device can be
configured to not allow a minimum pressure limit to be below 4 cm
H.sub.2O. As another example, the AutoPAP device can be configured
to not allow a maximum pressure limit to exceed 20 cm H.sub.2O.
Thus, if one or more conditions of the patient (e.g., the presence
or absence of SDBEs) indicate that the minimum and/or maximum
pressure available for therapy should change, the AutoPAP device
can leave one or both of the pressure limits unchanged if the
change would result in a pressure limit setting that is outside of
the defined allowable limits.
[0131] In block 210, the AutoPAP device measures at least one
characteristic capable of being used to determine one or more
traits of a sleep-disordered breathing event (SDBE), as described
elsewhere herein. The at least one characteristic may be analyzed
to determine the one or more traits of a sleep-disordered breathing
event of the patient, as described elsewhere herein.
[0132] In block 215, the AutoPAP device analyzes the traits of a
sleep-disordered breathing event of the patient to determine
whether to change the pressure range limits. As described herein,
the AutoPAP device can use measured information from the current
therapy session to make this determination. Similarly, the AutoPAP
device can use measured data from previous therapy sessions to make
this determination. Moreover, the AutoPAP device can use measured
data from the current therapy session in combination with one or
more previous therapy sessions or portions of one or more previous
therapy sessions to make this determination. In some embodiments,
the AutoPAP device makes this determination on an event-by-event
basis.
[0133] In this manner, the AutoPAP device can use the method 200 to
automatically limit the range of pressures used during respiratory
therapy. This can lead to greater efficacy in respiratory therapy,
greater patient compliance, and improved results relative to other
AutoPAP devices that do not adjust the pressure range limits in the
manners set forth herein.
[0134] Unless the context clearly requires otherwise, throughout
the description and the claims, the words "comprise", "comprising",
and the like, are to be construed in an inclusive sense as opposed
to an exclusive or exhaustive sense, that is to say, in the sense
of "including, but not limited to."
[0135] Where, in the foregoing description reference has been made
to integers or components having known equivalents thereof, those
integers are herein incorporated as if individually set forth.
[0136] The disclosed methods, media, apparatus and systems may also
be said broadly to consist in the parts, elements and features
referred to or indicated in the specification of the application,
individually or collectively, in any or all combinations of two or
more of said parts, elements or features.
[0137] Reference to any prior art in this specification is not, and
should not be taken as, an acknowledgement or any form of
suggestion that that prior art forms part of the common general
knowledge in the field of endeavor in any country in the world.
[0138] Certain features, aspects and advantages of some
configurations of the present disclosure have been described with
reference to use by a patient or user. However, certain features,
aspects and advantages of the use of the respiratory therapy system
as described may be advantageously practiced by other people on
behalf of the patient, including medical professionals, medical
device dealers, or medical device providers. Certain features,
aspects and advantages of the methods and apparatus of the present
disclosure may be equally applied to usage by other people.
[0139] Although the present disclosure has been described in terms
of certain embodiments, other embodiments apparent to those of
ordinary skill in the art also are within the scope of this
disclosure. Thus, various changes and modifications may be made
without departing from the spirit and scope of the disclosure. For
instance, various components may be repositioned as desired.
Moreover, not all of the features, aspects and advantages are
necessarily required to practice the present disclosure.
Accordingly, the scope of the present disclosure is intended to be
defined only by the claims that follow.
* * * * *