U.S. patent application number 10/657405 was filed with the patent office on 2005-02-24 for insufflation-exsufflation system for removal of broncho-pulmonary secretions with automatic triggering of inhalation phase.
Invention is credited to Emerson, George P..
Application Number | 20050039749 10/657405 |
Document ID | / |
Family ID | 34194688 |
Filed Date | 2005-02-24 |
United States Patent
Application |
20050039749 |
Kind Code |
A1 |
Emerson, George P. |
February 24, 2005 |
INSUFFLATION-EXSUFFLATION SYSTEM FOR REMOVAL OF BRONCHO-PULMONARY
SECRETIONS WITH AUTOMATIC TRIGGERING OF INHALATION PHASE
Abstract
An improved insufflation-exsufflation system for removal of
broncho-pulmonary secretions with automatic triggering of
inhalation phase includes a conduit for connection to a patient's
airway; a pressure source with a positive pressure port and a
negative pressure port; a switching device selectively connecting
the conduit to the positive pressure port, the negative pressure
port and the dwell port; the sensor system for sensing an
inhalation by the patient; and a controller system for driving the
switching device to connect the conduits sequentially to the
positive port, the negative port and the dwell port and to return
again to the positive port in response to the sensor system sensing
an inhalation by the patient while the conduit is connected to the
dwell port.
Inventors: |
Emerson, George P.;
(Arlington, MA) |
Correspondence
Address: |
Iandiorio & Teska
260 Bear Hill Road
Waltham
MA
02451-1018
US
|
Family ID: |
34194688 |
Appl. No.: |
10/657405 |
Filed: |
September 8, 2003 |
Current U.S.
Class: |
128/204.23 |
Current CPC
Class: |
A61M 16/106 20140204;
A61M 2016/0024 20130101; A61M 16/022 20170801; A61M 16/0006
20140204; A61M 16/0858 20140204; A61M 16/1055 20130101; A61M 16/202
20140204; A61M 2016/0027 20130101; A61M 16/0066 20130101; A61M
16/0009 20140204 |
Class at
Publication: |
128/204.23 |
International
Class: |
A62B 007/00; A61M
016/00 |
Claims
What is claimed is:
1. An improved insufflation-exsufflation system for removal of
broncho-pulmonary secretions with automatic triggering of
inhalation phase comprising: a conduit for connection to a
patient's airway; a pressure source with a positive pressure port
and a negative pressure port; a sensor system for sensing an
inhalation by the patient; and a controller system for driving said
switching device to connect said conduit sequentially to said
positive port, said negative port and said dwell port and to return
again to said positive port in response to said sensor system
sensing an inhalation by the patient when said conduit is connected
to said dwell port.
2. The improved insufflation-exsufflation system of claim 1 in
which said switching device includes a selector valve and an
actuator device.
3. The improved insufflation-exsufflation system of claim 1 in
which said sensor system includes a pressure sensor in said
conduit.
4. The improved insufflation-exsufflation system of claim 1 in
which said sensor system includes an airflow detector in said
conduit.
5. The improved insufflation-exsufflation system of claim 1 in
which said controller system includes a programmed timer.
6. The improved insufflation-exsufflation system of claim 1 in
which said dwell port is connected to atmospheric pressure.
7. The improved insufflation-exsufflation system of claim 1 in
which said dwell port includes a restrictor portion to increase
sensitivity.
Description
FIELD OF THE INVENTION
[0001] This invention relates to an improved
insufflation-exsufflation system with automatic triggering of
inhalation phase.
BACKGROUND OF THE INVENTION
[0002] The use of mechanical insufflation and exsufflation (MI-E)
with negative pressure is a well-known technique for helping
patients with an ineffective cough to remove secretions from the
respiratory tract. Patients who can benefit from the technique
include: post-polio, muscular dystrophy, spinal muscular atrophy
(SMA), post-cardiac surgery, amyotropic lateral sclerosis (ALS),
mechanically ventilated, or anyone with insufficient muscle
strength to generate the high expiratory flows necessary for moving
secretions up the tracheo-bronchial tree. The technique involves
the use of a blower and valve, which, via a facemask, mouthpiece or
adapter for a tracheal tube, alternately applies positive pressure
first to inflate the lungs, then shifts rapidly to negative
pressure to create a high expiratory flow.
[0003] During automatic operation of the device, the internal valve
executes a sequence of pressures applied to the patient's airway:
first positive pressure to inflate the lungs, then a shift to
negative pressure to create a high exhalation flow. This sequence
is typically repeated a number of times (anywhere from 2 to 6) in
succession for a treatment. The timing of each phase is adjustable
by the user. Also, the initiation of the sequence is begun by the
user actuating a switch. Alternatively, the user may also initiate
each phase by actuating a switch while in a manual mode.
[0004] One shortcoming of current MI-E devices is that the
beginning of an inhalation phase (positive pressure to first
inflate the lungs) is triggered by either the patient or the
patient's caregiver actuating a switch to begin the cycling. If the
sequence is begun while the patient is exhaling, or the patient is
not ready for an inhalation from the device, the patient may find
the first inhalation uncomfortable, and may even unconsciously
block the flow of air into the lungs. This can limit the
effectiveness of the treatment, since a full deep inhalation breath
is necessary to achieve adequate exhalation flow. Typically a
caregiver must "coach" the patient during a treatment, explaining
when to inhale, to avoid this problem. Alternatively, the caregiver
watches the patient's respiration in order to switch on the cycling
when the patient begins to inhale. Another shortcoming of the
current device is that it is difficult to use on very young
pediatric patients, and on unconscious or uncooperative patients,
where it is difficult to explain to the patient when to begin an
inhalation.
[0005] Assist modes have been used on positive pressure
ventilators, which "breathe" a patient by applying a positive
pressure to the airway, usually via an endotracheal or tracheostomy
tube. Such assist modes also detect the patient's inspiratory
effort in order to trigger the delivery of a breath by the
ventilator. More recently, the advent of bi-level Continuous
Positive Airway Pressure (CPAP) devices to support patients with
respiratory insufficiency has also resulted in the use of some
means to detect when the patient has begun inhalation, in order to
determine when to increase the pressure applied to the airway.
[0006] While automatic assist modes work well with positive
pressure ventilators they are not easily applicable to
insufflation-exsufflation systems. In positive pressure ventilators
the slight negative pressure or flow created by a patient
inhalation is used to trigger a delivery of positive pressure, the
breath or inhalation, for the patient. Then the positive pressure
is stopped as the patient exhales to atmospheric or slight positive
pressure. Following this the next negative pressure or flow sensed
when the patient again inhales can be used to trigger delivery of
the next positive pressure. In contrast in
insufflation-exsufflation systems after the inhale/positive
pressure comes the exhale negative pressure. After the time set for
the negative pressure the system will return to the positive
pressure but on the basis of the existing negative pressure which
may not be the negative pressure created by a patient inhalation,
thereby losing synchronism with the normal breathing of the
patient.
BRIEF SUMMARY OF THE INVENTION
[0007] It is therefore an object of this invention to provide an
improved insufflation-exsufflation system for removal of
broncho-pulmonary secretions.
[0008] It is a further object of this invention to provide such an
improved insufflation-exsufflation system with reliable automatic
triggering of the inhalation phase.
[0009] It is a further object of this invention to provide such an
improved insufflation-exsufflation system, which is easier to
synchronize with a patient's spontaneous breaths.
[0010] It is a further object of this invention to provide such an
improved insufflation-exsufflation system, which increases
inhalation volume for patients including unconscious,
uncooperative, and pediatric patients.
[0011] It is a further object of this invention to provide such an
improved insufflation-exsufflation system which is more comfortable
for patients.
[0012] The invention results from the realization that an improved
insufflation-exsufflation system for removal of broncho-pulmonary
secretions with automatic triggering of inhalation phase can be
effected by selectively connecting a patients breathing conduit to
a positive pressure port, a negative pressure port and a dwell
port, only after an inhalation of the patient has been sensed while
the conduit is connected to the dwell port.
[0013] This invention features an improved
insufflation-exsufflation system for removal of broncho-pulmonary
secretions with automatic triggering of the inhalation phase. There
is a conduit for connection to a patient's airway and a pressure
source with a positive pressure port and negative pressure port. A
switching device selectively connects the conduit to the positive
pressure port, the negative pressure port and a dwell port. A
sensor system senses an inhalation by the patient. A controller
system drives the switching device to connect the conduit
sequentially to the positive port, the negative port and the dwell
port and to return again to the positive port in response to the
sensor system sensing an inhalation by the patient while the
conduit is connected to the dwell port.
[0014] In a preferred embodiment the switching device may include a
selector valve or valves and an actuator device. The sensor system
may include a pressure sensor in the conduit or an airflow
detector. The controller system may include a programmed timer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Other objects, features and advantages will occur to those
skilled in the art from the following description of a preferred
embodiment and the accompanying drawings, in which:
[0016] FIG. 1 is a schematic block diagram of an
insufflation-exsufflation system according to this invention.
[0017] FIGS. 2 and 3 are schematic diagrams showing alternative
connections of the system to a patient's airway.
[0018] FIG. 4 shows an alternative embodiment of a sensor system
employing a flow sensor,
[0019] FIG. 5 is a more detailed schematic diagram of the
positive/negative pressure source of FIG. 1; and
[0020] FIG. 6 is a schematic diagram showing in more detail the
program timer of FIG. 5.
DISCLOSURE OF THE PREFERRED EMBODIMENT
[0021] Aside from the preferred embodiment or embodiments disclosed
below, this invention is capable of other embodiments and of being
practiced or being carried out in various ways. Thus, it is to be
understood that the invention is not limited in its application to
the details of construction and the arrangements of components set
forth in the following description or illustrated in the
drawings.
[0022] There is shown in FIG. 1 an improved
insufflation-exsufflation system 10 according to this invention,
including a positive/negative pressure source 12 and a conduit 14
through which it provides the positive and negative pressure to
patient 16 through, for example, a face mask 18. Alternatively,
conduit 14, FIG. 2, may be connected directly to a tracheostomy
tube 20 or as shown in FIG. 3, to an endotracheal tube 22. A
bacterial filter 24 may be employed in various location in conduit
14. A pressure transducer or pressure switch 26 may be employed to
sense the pressure in conduit 14. When it senses a slight negative
pressure indicative of an inhalation it provides a signal to
pressure source 12 to provide the positive pressure flow to assist
in the inhalation by the patient 16 and provides a signal over line
28. Alternatively, pressure transducer or pressure switch 26 may be
replaced by a flow sensor 26a, FIG. 4, or any other suitable device
which can sense the beginning of an inhalation by patient 16, for
example, electrodes, strain gauges, or chest strap devices may be
put on or around the patient's body or chest cavity to sense the
beginning of an inhalation independent of the actual airflow
characteristics in the airway of the patient.
[0023] Pressure source 12, FIG. 5, may include a conventional
blower 30 which provides a positive pressure during the inhale
cycle in line 32 at positive pressure port 34 and a negative
pressure during exhale in line 36 at negative pressure port 38.
Dwell port 40 is provided for connection to ambient or atmospheric
pressure, and may also include a flow restrictor 41 to make the
sensor 26 more sensitive when it is, for example, a pressure sensor
or pressure switch. Programmed timer 42, FIG. 5, drives actuator
device or actuator motor 44 which through eccentric drive 46 moves
swinger 48 of slider valve 50 from positive port 34 to negative
port 38, then to dwell port 40. Swinger 48 remains there until
sensor 26 senses that a patient inhalation has begun, at which
point it sends a signal on line 28 to program timer 42 to once
again operate actuator motor 44 to move slider switch 50 through
the cycle of positive port 34, negative port 38 and dwell port
40.
[0024] Programmed timer 42 may include a timer 60, FIG. 6, which
operates driver circuit 62 that causes actuator motor 44 to step
through the three positions of swinger 48: positive port 34,
negative port 38, and dwell port 40. An alternate output 59 of the
timer 60 (or of driver 62) indicates when the driver 62 is holding
the swinger 48 at the dwell port 40, and provides one input to AND
gate 66. When pressure sensor 26 senses that a patient inhalation
is beginning it also provides an input to AND gate 66. When both
those inputs are present at AND gate 66 it provides an output on
line 28 to timer 60 to start the cycle again beginning with
connection of swinger 48 to positive port 34.
[0025] Although specific features of the invention are shown in
some drawings and not in others, this is for convenience only as
each feature may be combined with any or all of the other features
in accordance with the invention. The words "including",
"comprising", "having", and "with" as used herein are to be
interpreted broadly and comprehensively and are not limited to any
physical interconnection. Moreover, any embodiments disclosed in
the subject application are not to be taken as the only possible
embodiments.
[0026] Other embodiments will occur to those skilled in the art and
are within the following claims:
* * * * *