U.S. patent application number 12/602292 was filed with the patent office on 2010-07-08 for improvements to electrically operable resuscitators.
Invention is credited to Gilbert Jacobus Kuypers, Richard Anthony McCulloch.
Application Number | 20100170512 12/602292 |
Document ID | / |
Family ID | 40075316 |
Filed Date | 2010-07-08 |
United States Patent
Application |
20100170512 |
Kind Code |
A1 |
Kuypers; Gilbert Jacobus ;
et al. |
July 8, 2010 |
Improvements to Electrically Operable Resuscitators
Abstract
The present invention relates to an electrically operable
resuscitation device comprising a pump including a rigid cylinder
including at least one gas inlet and at least one gas outlet, a
piston to travel in said cylinder, and at least one valve, the or
each valve configured to allow gas to be displaced into said
cylinder through said at least one gas inlet during at least one of
a first stroke direction and second stroke direction of said piston
in said cylinder, and for allowing gas to displaced through said at
least one gas outlet during an opposite of said at least one of the
first stroke direction and second stroke direction of said piston
in said cylinder; a motor, selected from one of a stepper motor and
feedback motor and stepper motor with feedback and linear motor,
operatively connected to said piston to move said piston in said
cylinder; a patient interface in ducted fluid connection with said
pump to receive gas via said at least one gas outlet and to deliver
said gas to said patient.
Inventors: |
Kuypers; Gilbert Jacobus;
(Auckland, NZ) ; McCulloch; Richard Anthony;
(Auckland, NZ) |
Correspondence
Address: |
DANN, DORFMAN, HERRELL & SKILLMAN
1601 MARKET STREET, SUITE 2400
PHILADELPHIA
PA
19103-2307
US
|
Family ID: |
40075316 |
Appl. No.: |
12/602292 |
Filed: |
May 30, 2008 |
PCT Filed: |
May 30, 2008 |
PCT NO: |
PCT/NZ2008/000128 |
371 Date: |
February 26, 2010 |
Current U.S.
Class: |
128/204.23 |
Current CPC
Class: |
A61M 2016/003 20130101;
A61M 2202/0208 20130101; A61M 2230/432 20130101; A61M 2205/3368
20130101; A61M 16/0072 20130101; A61M 16/04 20130101; A61M
2205/3334 20130101; A61M 16/0003 20140204; A61M 16/06 20130101;
A61M 2016/0036 20130101; A61M 2205/106 20130101; A61M 2016/0015
20130101; A61M 16/208 20130101; A61M 2230/06 20130101; A61M 16/209
20140204; A61M 16/0069 20140204; A61M 16/20 20130101; A61M 2230/42
20130101; A61M 2205/073 20130101; A61M 16/201 20140204; A61M 16/205
20140204; A61M 2205/502 20130101; A61M 2016/0027 20130101; A61M
16/0048 20130101; A61M 2205/3341 20130101; A61M 16/0666 20130101;
A61M 16/12 20130101; A61M 16/0875 20130101 |
Class at
Publication: |
128/204.23 |
International
Class: |
A61M 16/00 20060101
A61M016/00 |
Foreign Application Data
Date |
Code |
Application Number |
May 30, 2007 |
NZ |
555581 |
Claims
1. An electrically operable resuscitation device comprising: a) a
pump including a rigid cylinder including at least one gas inlet
and at least one gas outlet, a piston to travel in said cylinder,
and at least one valve, the or each valve configured to allow gas
to be displaced into said cylinder through said at least one gas
inlet during at least one of a first stroke direction and/or a
second stroke direction of said piston in said cylinder, and for
allowing gas to be displaced through said at least one gas outlet
during an opposite of said at least one of the first stroke
direction and/or second stroke direction of said piston in said
cylinder, b) a motor, selected from one of a stepper motor and
feedback motor or a stepper motor with feedback and linear motor,
operatively connected to said piston to move said piston in said
cylinder, c) a patient interface in ducted fluid connection with
said pump to receive gas via said at least one gas outlet and to
deliver said gas to said patient.
2. A device as claimed in claim 1 wherein said patient interface is
a face mask or an endotracheal tube or a naso-tube.
3. A device as claimed in claim 1 or claim 2 wherein said motor is
a linear stepper motor that may also have feedback.
4. A device as claimed in claim 1 or claim 2 wherein said motor is
a servo motor that may also have feedback.
5. A device as claimed in claim 1 or 2 wherein said motor is a
linear stepper motor and is directly connected to said piston.
6. A device as claimed in claim 1 or 2 wherein said motor is a
linear stepper motor and is in part integrally formed with said
piston.
7. A device as claimed in anyone of claims 1 to 6 wherein said
motor is controlled by controller to ensure accurate velocity
control of the motor.
8. A device as claimed in any one of the preceding claims wherein
the motor is indirectly connected with said piston, via a
linkage.
9. A device as claimed in any one of the preceding claims wherein
said piston includes a connection rod with which said motor is in
operative connection.
10. A device as claimed in claim 9 wherein said piston is or
includes one part of the two moving part linear motor.
11. A device as claimed in any one of the preceding claims wherein
the motor and cylinder are connected together (and are preferably
engaged to each other).
12. A device as claimed in any one of the preceding claims wherein
intermediate of the patient interface and the at least one outlet
of the cylinder and in said ducted fluid connection therewith is a
gas flow controller.
13. A device as claimed in claim 12 wherein the gas flow controller
includes a one way valve that allows gas to be displaced from the
outlet of the cylinder towards the patient interface and prevents
gas from flowing through the one way valve in the opposite
direction.
14. A device as claimed in claim 12 or 13 wherein the gas flow
controller includes a valved exhaust port via which gas can exhaust
to relieve pressure at the patient interface.
15. A device as claimed in claim 13 wherein said valved exhaust
port assumes a closed condition when the piston is moving in a
direction to displace gas towards the patient interface and assumes
an open condition when the piston is moving in the opposite
direction to allow gas due to exhalation of or by the patient to
pass through the exhaust port.
16. A device as claimed in claim 15 wherein said valved exhaust
port includes at least one opening closable by a valve, said valve
mounted on or to or in operative association with an actuator to
actively control the movement of the valve relative to the
opening.
17. A device as claimed in claim 15 wherein said valved exhaust
port includes at least one opening closable by a valve, said valve
mounted for movement relative the opening in a passive manner under
the influence of pressure differential in the gas from controller
and/or between the gas flow controller and ambient gas
pressure.
18. A device as claimed in claim 13 wherein said valved exhaust
port is moved to a closed condition when gas is to be displaced
into said patient and to an open condition to allow gas due to
exhalation of or by the patient to pass through the exhaust
port.
19. A device as claimed in claim 18 wherein said valved exhaust
port includes at least one opening closable by a valve, said valve
mounted on or to or in operative association with an actuator to
actively control the movement of the valve relative the
opening.
20. A device as claimed in claim 18 wherein said valved exhaust
port includes at least one opening closable by a valve, said valve
mounted for movement relative the opening in a passive manner under
the influence of pressure differential in the gas from controller
and/or between the gas flow controller and ambient gas
pressure.
21. A device as claimed in claims 18 to 20 wherein when the valved
exhaust port is in the open condition, said motor stops or reduces
the velocity of the piston.
22. A device as claimed in any one of the preceding claims wherein
a controller is coupled to said motor to control at least the
velocity and position of the motor.
23. A device as claimed in claim 22 when dependent on claim 16 or
19 wherein said controller is coupled to said actuator to move said
actuator preferably in a manner in synchronicity with control of
said motor.
24. A device as claimed in claim 22 or 23 wherein a source of
electricity is connected to said motor.
25. A device as claimed in claim 23 wherein said source of
electricity is connected to said motor via said controller.
26. A device as claimed in any one of claims 24 to 27 wherein via
an interface, the controller can be instructed to operate the
device in a suitable manner.
27. A device as claimed in claim 28 wherein the interface allows
for patient-related information to be entered into the controller,
the information including at least one selected from a patient's
age and weight.
28. A device as claimed in any one of claims 22 to 27 wherein the
controller receives data from other parts of the device, including
at least one of gas pressure at the patient interface and tidal
volume flow rate at the patient interface.
29. A device as claimed in any one of claims 1 to 28 wherein a
sensor is positioned at or proximate the patient interface in the
flow path to and from the patient to sense at least one of the
tidal volume flow rate, breath rate and exhale breath
temperature.
30. A device as claimed in claim 29 wherein said sensor (preferably
a resistive hotwire sensor) provides information to at least one of
a controller to control at least the motor and a recorder to record
the information and a display device to display the
information.
31. A device as claimed in any one of the preceding claims wherein
a display is provided to display operating conditions of said
device.
32. A device as claimed in claim 31 wherein the operating
conditions displayed include inlet gas pressure, patient interface
gas pressure, tidal volume at the patient interface, piston
oscillation rate, piston stroke length, battery power, duration
operation, each sensed by appropriate sensors of the device.
33. A device as claimed in claim 32 wherein the operating
conditions are recorded and stored for subsequent use.
34. A device as claimed in any one of the preceding claims wherein
fluid connection between said outlet of said cylinder and the
patient interface is defined in part by a flexible conduit.
35. A device as claimed in 34 wherein fluid connection between said
outlet of said cylinder and the patient interface is defined in
part by a flexible conduit and said flow controller is located more
proximate said patient interface than said cylinder.
36. A device as claimed in any one of the preceding claims wherein
the ducted fluid connection and/or the patient interface includes a
pressure relief valve to allow pressure reduction of gas in said
patient interface.
37. A device as claimed in any one of the preceding claims wherein
the pressure relief valve becomes operative to relieve pressure
when the pressure in said patient interface reaches a certain
threshold.
38. A device as claimed in any one of the preceding claims wherein
said pump includes an inlet volute.
39. A device as claimed in claim 38 wherein the inlet volute
includes an opening to allow pressure relief of said inlet volute
to occur.
40. A device as claimed in claim 38 or 39 wherein said inlet volute
includes a one way valve to allow pressure relief to occur into the
inlet volute.
41. A device as claimed in any one of claim 38 or 40 wherein the
said inlet volute includes a pressure relief valve to allow
pressure relief to occur out of said inlet volute.
42. A device as claimed in any one of the preceding claims wherein
said inlet of said cylinder is in fluid connection with a
supplementary gas supply to allow gas from said supplementary gas
supply to pass into said cylinder for subsequent delivery to the
patient, preferably the gas is oxygen.
43. A device as claimed in any one of the preceding claims wherein
said cylinder is split into two zones by said piston, a first zone
being on one side of said piston and a second zone being on the
other side of said piston and wherein said gas inlet(s) are
provided to allow gas into the first zone and said gas outlet(s)
are provided to allow gas out of said second zone, wherein a one
way pump valve is provided to allow gas to transfer from said first
zone to said second zone and that restricts flow in the opposite
direction.
44. A device as claimed in claim 43 wherein the one way pump valve
is carried by the piston to operate on a passage through the
piston.
45. A device as claimed in claim 43 or 44 wherein said gas in said
first zone, is or becomes pressurised sufficiently to, upon the
movement of the piston in its first stroke direction, allow some of
the gas to displace through the one way pump valve into the second
zone.
46. A device as claimed in any one of claims 43 to 45 wherein the
one way pump valve is a passive one way valve that moves between an
open and closed condition dependent on pressure differential across
the one way pump valve.
47. A device as claimed in any one of claims 43 to 45 wherein a one
way valve (inlet one way valve) may be provided to allow gas to be
drawn into the first zone upon the movement of the piston in its
second stroke direction and that restricts flow of gas in the
opposite direction through said inlet one way valve upon the
movement of the piston in the first stroke direction.
48. A device as claimed in claim 47 wherein the inlet one way valve
is a passive one way valve that moves between an open and closed
condition dependent on pressure differential across the inlet one
way valve.
49. A device as claimed in any one of claims any one of claims 43
to 45 wherein one or each of the one way valves mentioned are
valves under active control to be in the open and closed conditions
in correspondence with the direction of movement of the piston.
50. A device as claimed in anyone if claims 43 to 45 wherein the
cylinder and piston stroke length are of a size to allow a
sufficient volume of gas to be displaced from said cylinder through
said gas outlet(s) during said second direction of movement of the
piston to deliver a desired volume and flow rate of gas for a
single inhalation to a neonatal patient for resuscitation
purposes.
51. A device as claimed in any one of claims 1 to 43 wherein said
cylinder is split into two zones by said piston, a first zone being
on one side of said piston and a second zone being on the other
side of said piston, and wherein the pump is a double acting pump
that includes: a) a first one way valve to i) allow gas to enter
into the first zone via a said gas inlet (herein after "first gas
inlet") of said cylinder during movement of the piston in its
second direction of movement, and ii) restrict gas flow in the
opposite direction through said first gas inlet during movement of
the piston in the first direction of movement b) a second one way
valve to i) allow gas to exit the first zone via a said gas outlet
(herein after "first gas outlet") of said cylinder during movement
of the piston in its first direction of movement, and ii) restrict
gas flow in the opposite direction through said first gas outlet
during movement of the piston in the second direction of movement
c) a third one way valve to i) allow gas to enter into the second
zone via a said gas inlet (herein after "second gas inlet") of said
cylinder during movement of the piston in its first direction of
movement, and ii) restrict gas flow in the opposite direction
through said second gas inlet during movement of the piston in the
second direction of movement d) a fourth one way valve to i) allow
gas to exit the second zone via a said gas outlet (herein after
"second gas outlet") of said cylinder during movement of the piston
in its second direction of movement, and ii) restrict gas flow in
the opposite direction through said second gas outlet during
movement of the piston in the first direction of movement e) a
manifold or ducting to duct gas from said first and second outlets
to said patient interface.
52. A device as claimed in claim 51 wherein each of at least one of
the first to fourth one way valves are either actively controlling
or passive in moving between their open and closed conditions.
53. A device as claimed in claim 51 or 52 wherein the cylinder and
piston stroke length are of a size, and the motor is able to move
and be controlled, to allow a sufficient volume of gas to be
displaced from said cylinder through said gas outlet(s) during
multiple oscillations of the piston to deliver a desired volume and
flow rate of gas for a single inhalation to a patient for
resuscitation purposes or ventilation purposes or both.
54. A device as claimed in claim 1 wherein the pump is a double
acting pump and the motor is of sufficient speed to, in multiple
stokes of the piston, deliver a single tidal volume of gas for a
single inhalation to a patient for resuscitation purposes.
55. A device as claimed in any one of the preceding claims wherein
the device is portable.
56. A device as claimed in any one of the preceding claims wherein
at least one of the pump and patient interface and motor are
portable and preferably unitary and preferably able to be held in
one hand by a user.
57. A device as claimed in claim 56 wherein at least one of the
controller and power supply and display are also portable and
preferably unitary and preferably able to be held in one hand by a
user.
58. A device as claimed in any one of the preceding claims wherein
communication to and from the controller may be wireless.
59. A resuscitator to deliver gas to a patient to be resuscitated
that includes a positive displacement pump that is operated by a
linear motor.
60. A resuscitator as claimed in claim 59 wherein the pump is of a
kind to allow continuous displacement gas to a patient to occur
during operation of the pump and the velocity of linear motor is
controlled to displace gas to the patient in a manner to facilitate
resuscitation.
61. A resuscitator as claimed in claim 60 wherein the control of
the linear motor is such as to change its velocity to provide a
variation in the volume of gas delivered.
62. A resuscitator as claimed in any one of claims 59 to 61 wherein
the pump is a positive displacement pump (preferably a piston and
cylinder pump).
63. A resuscitator as claimed in claim 52 wherein the linear motor
actuates the piston for multiple oscillations to deliver a single
tidal volume of gas to the patient.
64. A gas flow controller for a resuscitator that includes a pump
to pressurise a gas for delivery to a patient and a patient
interface, the controller interposed between said pump and
interface and including a one way valve that allows gas to be
displaced from the pump towards the patient interface and prevents
gas from flowing through the one way valve in the opposite
direction.
65. A controller as claimed in claim 64 wherein the gas flow
controller includes a valved exhaust port via which gas can exhaust
to relieve pressure at the patient interface.
66. A controller as claimed in claim 64 or 65 wherein said valved
exhaust port assumes a closed condition when the pump is operating
in a mode to displace gas towards the patient interface and assumes
an open condition during exhalation of or by the patient to allow
exhaled gas to pass through the exhaust port.
67. A controller as claimed in claim, any one of claims 64 to 66
wherein the valved exhaust port assumes an open condition when the
pump is in a non-operative or non-operational mode.
68. A controller as claimed in claim any one of claims 64 to 66
wherein the valved exhaust port assumes an open condition when the
pump is in a non-operative or non-operational mode.
69. A controller as claimed in claim 66 wherein said valved exhaust
port includes at least one opening closable by a valve, said valve
is mounted on or to or in operative association with an actuator to
actively control the movement of the valve relative the
opening.
70. A controller as claimed in claim 66 wherein said valved exhaust
port includes at least one opening closable by a valve, said valve
mounted for movement relative the opening in a passive manner under
the influence of pressure differential in the gas from controller
and/or between the gas flow controller and ambient gas
pressure.
71. A controller as claimed in claim 65 wherein said valved exhaust
port is moved to a closed condition when gas is to be displaced
into said patient and to an open condition to allow gas due to
exhalation of or by the patient to pass through the exhaust
port.
72. A controller as claimed in claim 71 wherein said valved exhaust
port includes at least one opening closable by a valve, said valve
mounted on or to or in operative association with an actuator to
actively control the movement of the valve relative to the
opening.
73. A controller as claimed in claim 71 wherein said valved exhaust
port includes at least one opening closable by a valve, said valve
mounted for movement relative the opening in a passive manner under
the influence of pressure differential in the gas from controller
and/or between the gas flow controller and ambient gas
pressure.
74. A resuscitator device that operates to define an inhalation
period during which a gas is displaced from the device to the
patient and an exhalation period where no gas is displaced from the
device to the patient and any gas received from the patient is
exhausted from the device, wherein the device utilises an accurate
positional control motor (eg a linear motor or rotary stepper
motor) that controls a pump, the motor being controlled to operate
the pump during the inhalation period and the motor being
controlled to stop the pump during the exhalation period.
75. A device as claimed in claim 74 wherein the pump undertakes a
plurality of oscillations during any one inhalation period.
76. A device as claimed in claim 74 wherein the pump undertakes no
more than one oscillation during any one inhalation period.
77. A resuscitator as claimed in any one of claims 1 to 63 and
substantially as herein described with reference to any one of the
accompanying drawings.
78. A resuscitator as claimed in any one of claims 74 to 76 and
substantially as herein described with reference to any one of the
accompanying drawings.
79. A gas flow controller as claimed in any one of claims 64 to 73
and substantially as herein described with reference to any one of
the accompanying drawings.
80. A resuscitator as herein described with reference to any one of
the accompanying drawings.
81. A gas flow controller as herein described with reference to any
one of the accompanying drawings.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to improvements to
resuscitators.
BACKGROUND TO THE INVENTION
[0002] Resuscitators that can supply pressurised air or oxygen to a
patient are well-known. Examples include bag or bellows type
resuscitators and pump-like resuscitators and pressure-limited
resuscitators. However, there are limitations in certain
resuscitators. For example, there is a risk of overinflating a
patient's lungs by delivering a volume of air that is greater than
desirable. There is also a risk the pressure of the air or oxygen
delivered may be at undesirably high levels. Such undesirable
characteristics of the air being delivered to the patient can have
adverse affects on the patient. If a patient's airway passage is or
becomes blocked and air is delivered by the known devices then
undesirable pressures may be reached. Further such increased
pressure may cause sudden dislodgement of the blockage and may lead
to serious consequences for the patient. Known devices do not
readily lend themselves to predetermination of airway pressures and
volumes to which the lungs of the patient are being subjected by
the operator of the device. The operator may feel a resistance when
they are applying a force to the device to deliver air or oxygen.
The operator may increase the force to overcome the blockage.
However, when the blockage clears there is a risk of
over-pressurising or overfilling the lungs, thereby causing
barotrauma or volutrauma or both.
[0003] Eliminating human operation of a resuscitator for delivering
air to a patient is advantageous. By eliminating the operator the
risk of delivering too great a volume of air into the patient and
overinflating the patient's lungs, causing volutrauma, is reduced.
By eliminating the operator the risk of delivering too great a
pressure of air into the patient and therefore over pressurising
the patient's lungs, causing barotrauma, is reduced. In
resuscitation it is desirable to start at the lowest risk procedure
to the patient. The lowest risk procedure is volume resuscitation
rather than pressure-limited resuscitation or manual-controlled
resuscitation.
[0004] In known devices there is the risk that an operator may
displace too great a volume of air into the patient and therefore
overinflate the patient's lungs. There is also the risk of applying
a pressure that is too great for the patient's lungs. For example,
when the airway passage is blocked, prior art systems do not signal
that the operator should stop and remove the blockage.
[0005] It would therefore be an advantage to provide improvements
to resuscitators that addresses or goes at least someway towards
addressing at least some of the abovementioned disadvantages and/or
addresses at least some of the abovementioned advantages or that
will at least provide the public or industry or both with a useful
choice.
SUMMARY OF THE INVENTION
[0006] Accordingly in a first aspect the present invention consists
in an electrically operable resuscitation device comprising:
[0007] (a) a pump including
[0008] a rigid cylinder including at least one gas inlet and at
least one gas outlet,
[0009] a piston to travel in said cylinder, and
[0010] at least one valve, the or each valve configured for
allowing gas to be drawn into said cylinder through said at least
one gas inlet during at least one of a first stroke direction
and/or a second stroke direction of said piston in said cylinder,
and for allowing gas to be displaced through said at least one gas
outlet during an opposite of at least one of the first stroke
direction and/or second stroke direction of said piston in said
cylinder,
[0011] (b) accurate positional control motor preferably selected
from a stepper motor and feedback motor or a stepper motor with
feedback and linear motor, operatively connected to said piston to
move said piston in said cylinder with accurate velocity
control,
[0012] (c) a patient interface in ducted fluid connection with said
pump to receive gas via said at least one gas outlet and to deliver
said gas to said patient.
[0013] Preferably said patient interface is a face mask or
endotracheal tube or naso-tube.
[0014] Preferably said motor is a linear stepper motor that may
also have feedback.
[0015] Preferably said motor is a servo motor that may also have
feedback.
[0016] Preferably said motor is a linear stepper motor and is
directly connected to said piston.
[0017] Preferably the motor is indirectly connected with said
piston, via a linkage.
[0018] Preferably said piston includes a connection rod with which
said motor is in operative connection.
[0019] Preferably said piston is or includes one part (eg an iron
bar and rare earth magnet assembly) of the two moving part linear
motor.
[0020] Preferably the motor and cylinder are connected together
(and are preferably engaged to each other).
[0021] Preferably wherein intermediate of the patient interface and
the at least one outlet of the cylinder and in said ducted fluid
connection therewith is a gas flow controller.
[0022] Preferably the gas flow controller includes a one way valve
that allows gas to be displaced from the outlet of the cylinder
towards the patient interface and prevents gas from flowing through
the one way valve in the opposite direction.
[0023] Preferably the gas flow controller includes a valved exhaust
port via which gas can exhaust to relieve pressure at the patient
interface.
[0024] Preferably said valved exhaust port assumes a closed
condition when the piston is moving in a direction to displace gas
towards the patient interface and assumes an open condition when
the piston is moving in the opposite direction to allow gas due to
exhalation of or by the patient to pass through the exhaust
port.
[0025] Preferably said valved exhaust port includes at least one
opening closable by a valve, said valve mounted on or to or in
operative association with an actuator to actively control the
movement of the valve relative the opening.
[0026] Preferably said valved exhaust port includes at least one
opening closable by a valve, said valve mounted for movement
relative the opening in a passive manner under the influence of
pressure differential in the gas from controller and/or between the
gas flow controller and ambient gas pressure.
[0027] Preferably said valved exhaust port is moved to a closed
condition when gas is to be displaced into said patient and to an
open condition to allow gas due to exhalation of or by the patient
to pass through the exhaust port.
[0028] Preferably said valved exhaust port includes at least one
opening closable by a valve, said valve mounted on or to or in
operative association with an actuator to actively control the
movement of the valve relative to the opening.
[0029] Preferably said valved exhaust port includes at least one
opening closable by a valve, said valve mounted for movement
relative the opening in a passive manner under the influence of
pressure differential in the gas from controller and/or between the
gas flow controller and ambient gas pressure.
[0030] Preferably when the valved exhaust port is in the open
condition, said motor stops or reduces the velocity of the
piston.
[0031] Preferably a controller is coupled to said motor to control
at least the velocity and position of the motor.
[0032] Preferably said controller is coupled to said actuator to
move said actuator preferably in a manner in synchronicity with
control of said motor.
[0033] Preferably a source of electricity is connected to said
motor.
[0034] Preferably said source of electricity is connected to said
motor via said controller.
[0035] Preferably via an interface, the controller can be
instructed to operate the device in a suitable manner.
[0036] Preferably the interface allows for patient-related
information to be entered into the controller, the information
including at least one selected from a patient's age and
weight.
[0037] Preferably the controller receives data from other parts of
the device, including at least one of gas pressure at the patient
interface and tidal volume flow rate at the patient interface.
[0038] Preferably a display is provided to display operating
conditions of said device.
[0039] Preferably the operating conditions displayed may include
inlet gas pressure, patient interface gas pressure, tidal volume at
the patient interface, piston oscillation rate, piston stroke
length, battery power, duration operation.
[0040] Preferably the operating conditions may also be recorded for
subsequent reference.
[0041] Preferably fluid connection between said outlet of said
cylinder and the patient interface is defined in part by a flexible
conduit.
[0042] Preferably fluid connection between said outlet of said
cylinder and the patient interface is defined in part by a flexible
conduit and said flow controller is located more proximate said
patient interface than said cylinder.
[0043] Preferably the ducted fluid connection and/or the patient
interface includes a pressure relief valve to allow pressure
reduction of gas in said patient interface.
[0044] Preferably the pressure relief valve becomes operative to
relieve pressure when the pressure in said patient interface
reaches a certain threshold.
[0045] Preferably said pump includes an inlet volute.
[0046] Preferably the inlet volute includes an opening to allow
pressure relief of said inlet volute to occur.
[0047] Preferably said inlet volute includes a one way valve to
allow pressure relief to occur into the inlet volute.
[0048] Preferably the said inlet volute includes a pressure relief
valve to allow pressure relief to occur out of said inlet
volute.
[0049] Preferably said inlet of said cylinder is in fluid
connection with a supplementary gas supply to allow gas from said
supplementary gas supply to pass into said cylinder for subsequent
delivery to the patient. More preferably, the gas is oxygen.
[0050] Preferably said cylinder is split into two zones by said
piston, a first zone being on one side of said piston and a second
zone being on the other side of said piston and wherein said gas
inlet(s) are provided to allow gas into the first zone and said gas
outlet(s) are provided to allow gas out of said second zone,
wherein a one way pump valve is provided to allow gas to transfer
from said first zone to said second zone and that restricts flow in
the opposite direction.
[0051] Preferably the one way pump valve is carried by the piston
to operate on a passage through the piston.
[0052] Preferably gas in said first zone, is or becomes pressurised
sufficiently to, upon the movement of the piston in its first
stroke direction, allow some of the gas to displace through the one
way pump valve into the second zone.
[0053] Preferably the one way pump valve is a passive one way valve
that moves between an open and closed condition dependent on
pressure differential across the one way pump valve.
[0054] Preferably a one way valve (inlet one way valve) may be
provided to allow gas to be drawn into the first zone upon the
movement of the piston in its second stroke direction and that
restricts flow of gas in the opposite direction through said inlet
one way valve upon the movement of the piston in the first stroke
direction.
[0055] Preferably the inlet one way valve is a passive one way
valve that moves between an open and closed condition dependent on
pressure differential across the inlet one way valve.
[0056] Preferably one or each of the one way valves mentioned are
valves under active control to be in the open and closed conditions
in correspondence with the direction of movement of the piston.
[0057] Preferably the cylinder and piston stroke length are of a
size to allow a sufficient volume of gas to be displaced from said
cylinder through said gas outlet(s) during said second direction of
movement of the piston to deliver a desired volume and flow rate of
gas for a single inhalation to a neonatal patient for resuscitation
purposes.
[0058] Preferably said cylinder is split into two zones by said
piston, a first zone being on one side of said piston and a second
zone being on the other side of said piston, and wherein the pump
is a double acting pump that includes:
[0059] (a) a first one way valve to [0060] i) allow gas to enter
into the first zone via a said gas inlet (herein after "first gas
inlet") of said cylinder during movement of the piston in its
second direction of movement, and [0061] ii) restrict gas flow in
the opposite direction through said first gas inlet during movement
of the piston in the first direction of movement
[0062] (b) a second one way valve to [0063] i) allow gas to exit
the first zone via a said gas outlet (herein after "first gas
outlet") of said cylinder during movement of the piston in its
first direction of movement, and [0064] ii) restrict gas flow in
the opposite direction through said first gas outlet during
movement of the piston in the second direction of movement
[0065] (c) a third one way valve to [0066] i) allow gas to enter
into the second zone via a said gas inlet (herein after "second gas
inlet") of said cylinder during movement of the piston in its first
direction of movement, and [0067] ii) restrict gas flow in the
opposite direction through said second gas inlet during movement of
the piston in the second direction of movement
[0068] (d) a fourth one way valve to [0069] i) allow gas to exit
the second zone via a said gas outlet (herein after "second gas
outlet") of said cylinder during movement of the piston in its
second direction of movement, and [0070] ii) restrict gas flow in
the opposite direction through said second gas outlet during
movement of the piston in the first direction of movement
[0071] (e) a manifold or ducting to duct gas from said first and
second outlets to said patient interface.
[0072] Preferably each of at least one of the first to fourth one
way valves are either actively controlling or passive in moving
between their open and closed conditions.
[0073] Preferably the cylinder and piston stroke length are of a
size, and the motor is able to move and be controlled, to allow a
sufficient volume of gas to be displaced from said cylinder through
said gas outlet(s) during multiple oscillations of the piston to
deliver a desired volume and flow rate of gas for a single
inhalation to a patient for resuscitation purposes or ventilation
purposes or both.
[0074] Preferably the pump is a double acting pump and the motor is
of a sufficient speed to, in multiple stokes of the piston, deliver
a single tidal volume of gas for a single inhalation to a patient
for ventilation and/or resuscitation purposes.
[0075] Preferably the device is portable.
[0076] Preferably at least one of the pump and patient interface
and motor are portable and preferably unitary and preferably able
to be held in one hand by a user.
[0077] Preferably at least one of the controller and power supply
and display are also portable and preferably unitary and preferably
able to be held in one hand by a user.
[0078] Preferably communication to and from the controller may be
wireless.
[0079] In a second aspect the present invention consists in a
resuscitator to deliver gas to a patient to be resuscitated that
includes a positive displacement pump that is operated by a linear
motor.
[0080] Preferably the pump is of a kind to allow continuous
displacement gas to a patient to occur during operation of the pump
and the velocity of linear motor is controlled to displace gas to
the patient in a manner to facilitate resuscitation.
[0081] Preferably the control of the linear motor is such as to
change its velocity to provide a variation in the volume of gas
delivered.
[0082] Preferably the pump is a positive displacement pump
(preferably a piston and cylinder pump).
[0083] Preferably the linear motor actuates the piston for multiple
oscillations to deliver a single tidal volume of gas to the
patient.
[0084] In a further aspect the present invention consists in a gas
flow controller for a resuscitator that includes a pump to
pressurise a gas for delivery to a patient and a patient interface,
the controller interposed between said pump and interface and
including a one way valve that allows gas to be displaced from the
pump towards the patient interface and prevents gas from flowing
through the one way valve in the opposite direction.
[0085] Preferably the gas flow controller includes a valved exhaust
port via which gas can exhaust to relieve pressure at the patient
interface.
[0086] Preferably said valved exhaust port assumes a closed
condition when the pump is operating in a mode to displace gas
towards the patient interface and assumes an open condition during
exhalation of or by the patient to pass allow exhaled gas to pass
through the exhaust port.
[0087] Preferably, said valved exhaust port assumes an open
condition when the device is in a non-operative or non-operational
mode. More preferably, the valved exhaust port assumes an open
condition when the pump is in a non-operative or non-operational
mode.
[0088] Preferably said valved exhaust port includes at least one
opening closable by a valve, said valve mounted on or to or in
operative association with an actuator to actively control the
movement of the valve relative the opening.
[0089] Preferably said valved exhaust port includes at least one
opening closable by a valve, said valve is mounted for movement
relative the opening in a passive manner under the influence of
pressure differential in the gas from controller and/or between the
gas flow controller and ambient gas pressure.
[0090] Preferably said valved exhaust port is moved to a closed
condition when gas is to be displaced into said patient and to an
open condition to allow gas due to exhalation of or by the patient
to pass through the exhaust port.
[0091] Preferably said valved exhaust port includes at least one
opening closable by a valve, said valve mounted on or to or in
operative association with an actuator to actively control the
movement of the valve relative the opening.
[0092] Preferably said valved exhaust port includes at least one
opening closable by a valve, said valve mounted for movement
relative the opening in a passive manner under the influence of
pressure differential in the gas from controller and/or between the
gas flow controller and ambient gas pressure.
[0093] In a further aspect the present invention consists in a
resuscitator device that operates to define an inhalation period
during which a gas is displaced from the device to the patient and
an exhalation period where no gas is displaced from the device to
the patient and any gas received from the patient is exhausted from
the device, wherein the device utilises an accurate positional
control motor (eg a linear motor or rotary stepper motor) that
controls a pump, the motor being controlled to operate the pump
during the inhalation period and the motor being controlled to stop
the pump during the exhalation period.
[0094] Preferably the pump undertakes a plurality of oscillations
during any one inhalation period.
[0095] Preferably the pump undertakes no more than one oscillation
during any one inhalation period.
[0096] In a further aspect the present invention consists in a
resuscitator as herein before described and as herein described
with reference to the accompanying drawings.
[0097] In a further aspect the present invention consists in a
resuscitator as herein described with reference to the accompanying
drawings.
[0098] This invention 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, and
any or all combinations of any two or more of said parts, elements
or features, and where specific integers are mentioned herein which
have known equivalents in the art to which this invention relates,
such known equivalents are deemed to be incorporated herein as if
individually set forth.
[0099] As used herein the term "and/or" means "and" or "or", or
both.
[0100] As used herein "(s)" following a noun means the plural
and/or singular forms of the noun.
[0101] The term "comprising" as used in this specification means
"consisting at least in part of". When interpreting statements in
this specification which include that term, the features, prefaced
by that term in each statement, all need to be present but other
features can also be present. Related terms such as "comprise" and
"comprised" are to be interpreted in the same manner.
[0102] It is intended that reference to a range of numbers
disclosed herein (for example, 1 to 10) also incorporates reference
to all rational numbers within that range (for example, 1, 1.1, 2,
3, 3.9, 4, 5, 6, 6.5, 7, 8, 9 and 10) and also any range of
rational numbers within that range (for example, 2 to 8, 1.5 to 5.5
and 3.1 to 4.7).
BRIEF DESCRIPTION OF THE DRAWINGS
[0103] A preferred form of the present invention will now be
described with reference to the accompanying drawings in which,
[0104] FIG. 1 is a schematic view of a resuscitator and is shown to
describe it being in the inhalation phase,
[0105] FIG. 2 is a schematic view of a resuscitator and is shown to
describe it in the exhalation phase,
[0106] FIG. 3 shows the resuscitator in a C-pap mode wherein a
supplementary gas is supplied to the resuscitator,
[0107] FIG. 4 is a schematic view of a variation of the
resuscitator shown in FIGS. 1-3, also in a C-pap mode and wherein a
flexible conduit extends between parts of the resuscitator to
provide to some extent, independence of movement of the face mask
relative some of the other components of the resuscitator,
[0108] FIG. 5 is a schematic view of a variation of the
resuscitator shown in an exhalation phase with reference to FIGS.
1-4,
[0109] FIG. 6 is a schematic view of the resuscitator of FIG. 5
shown in operation, moving in an inhalation phase,
[0110] FIG. 7 is a schematic view of the resuscitator of FIG. 5
shown in an inhalation phase,
[0111] FIG. 8 shows the resuscitator of FIG. 5 in an inhalation
mode and wherein an oxygen supply is provided to allow the
operation of the resuscitator in a C-pap mode,
[0112] FIG. 9 illustrates the resuscitator of FIG. 5, wherein a
flexible conduit is provided intermediate of certain parts of the
resuscitator to provide, to a certain extent, independence of
movement of the face mask relative to some of the other components
of the resuscitator,
[0113] FIG. 10 is a sectional view of the face mask shown to
include a flow and tidal volume sensor wherein the gas flow is
shown in an inhalation direction, and
[0114] FIG. 11 is a variation to that shown in FIG. 10 wherein it
is shown in an exhalation condition.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0115] With reference to FIG. 1, there is shown a resuscitator 1.
The resuscitator 1 consists of a resuscitator body 2. It may also
include associated hardware such as a controller 3, a display 4 and
power supply 5 connected to each other and/or the resuscitator body
2.
[0116] The resuscitator body 2 consists of a pump unit 6, a flow
control unit 7 and a patient interface 8.
[0117] Broadly speaking the pump unit 6 includes a pump that will
deliver air to the flow control unit 7. The flow control unit 7
will control the flow of gas between the patient interface and the
flow control unit 7 in conjunction with or without the pump unit 6
depending on the status of operation of the resuscitator 1.
[0118] In the most preferred form the pump unit 6 and flow control
unit 7 are part of the same body as for example shown in FIG. 1. A
conduit 9 extending between the flow control unit 7 and the patient
interface 8 facilitates the flow of gas between the interface and
the flow control unit 7.
[0119] In the examples shown in the accompanying drawings, the
interface is preferably a face mask. However, alternatively, the
interface may be an endotracheal tube or naso-tube that extends
partly into the patient's airway.
[0120] The pump unit 6 consists of a piston 10 that locates in a
cylinder 11 to displace gas through an outlet 12 of the cylinder
and to the flow control unit 7. The piston and cylinder are a
complementary shape and make sure that a sufficiently tight seal
exists between the piston and cylinder for the purposes of
positively displacing gas through the outlet 12.
[0121] The cylinder 11 may be cylindrical in cross-section or may
be any other shape in cross-section.
[0122] The piston is actuated via its connection rod 14, by a motor
13. In the most preferred form the motor is an actuator preferably
a linear motor. In an alternative form the actuator may be a
servomotor, stepper motor or similar device. The connection rod 14
may be the reactor to operate in conjunction with the motor 13 for
the purposes of displacing the piston 10 in the cylinder 11 in an
oscillating manner. Alternatively the connection rod 14 may carry a
reactor plate or surface in conjunction with the motor 13. In the
figures, the connection rod 14 is acted upon directly by the motor
13. The reactor plate may also be incorporated as part of the
piston to be integral therewith. No connection rod may then be
provided. Alternative mechanisms may be employed where such action
is indirect via a linkage mechanism. Such linkage may include a
rotor and crank and connection rod.
[0123] In the most preferred form the motor 13 is a linear motor or
any other motor that has accurate and rapid positional control
capabilities. The controller 3 via a connection 15 with the motor
13 will operate the motor in a manner so that the desired flow
rate, volume and pressures are being delivered through the outlet
opening 12.
[0124] The flow control unit 7 consists of an inlet that may
coincide with or define the outlet 12 of the pump unit. The flow
control unit includes an outlet 20 and a passage extending between
the inlet and outlet. The passage allows the transmission of gas
being displaced from the pump unit 6 to the outlet 20. The outlet
20, preferably via a conduit 9, allows the delivery of this gas to
the patient interface 8.
[0125] Intermediate of the inlet and outlet of the flow control
unit is a one-way valve 21. The one-way valve allows for gas to
travel from the inlet towards the outlet via the passage but
prevents flow of gas from the outlet to the inlet.
[0126] The valve 21 may be mounted in a fixed manner to the housing
22 of the flow control unit 7 or alternatively and as shown in FIG.
1, may be mounted to a movable mount 23 to move the valve
mount.
[0127] In the preferred form the movable mount 23 forms part of a
voice coil actuator 24 that can displace the movable mount 23
between two positions. The first position is as shown in FIG. 1 and
the second position is as shown in FIG. 2. This creates a valve
referred to herein as the exhalation or exhaust valve. In FIG. 1
the moveable mount 23 is located in a position so that at least on
the outlet 20 side of the valve 21, no other opening to the passage
of the flow control unit 7 is created. All gas that is displaced by
the pump unit 6 is captured for flow towards the patient interface
8.
[0128] In the second position of the mount as shown in FIG. 2, an
opening 27 is created between part of the housing 22 of the flow
control unit 7 and the moveable mount 23. In this position gas can
escape from that part of the passage of the flow control unit 7
intermediate of the valve 21 and the flow control unit outlet 20.
In this position of the moveable mount 23, gas that may be exhaled
from the patient can travel through the opening 27 for example
towards the surrounding atmosphere through opening 29. The opening
27 may be an annular opening that is created between a
substantially disk shaped mount portion and a circular shaped seat
30 of the housing 22 of the flow control unit 7.
[0129] As a consequence of a pressure differential between the
patient side and pump side of the one-way valve 21, the one-way
valve 21 will assume a closed position as shown in FIG. 2 during
the exhalation operating phase of the resuscitator. This negative
pressure differential may be established by one or more of a
combination of the patient breathing out, the retraction of the
piston in its cylinder away from the outlet 12 and the movement of
the voice coil actuator 24 in a direction establishing the opening
27. In the most preferred form it is the voice coil actuator 24
that primarily establishes the open and closed condition between
the opening 27 and that part of the passage of the flow control
unit 7 between the flow control unit outlet 20 and the one-way
valve 21. However where a patient is breathing on their own and is
able to create sufficient pressure, movement of the moveable mount
23 of the valve 21 to create the opening 27 may occur without
assistance of the voice coil actuator. It will be appreciated that
other actuators may be used. Actuators that move other components
other than the valve 21 to create such an opening for exhaled gases
to be discharged may be used.
[0130] In the exhalation operating phase of the resuscitator, the
piston is withdrawn by the motor 13 preferably back to a
predetermined start position. The piston retracts once it has
traveled its full desired stroke during the inhalation operating
phase and has delivered the required tidal volume or has timed out
while holding the maximum airway pressure during the inhalation
period. Control of the position or movement of the voice coil
actuator 24 can occur by the controller 3 and is preferably
synchronised with movement of the piston.
[0131] In a "PEEP" mode (positive end expiratory pressure)
parameters can be preset by using the controller or the display
panel PEEP so that pressure is controlled by the voice coil
actuator. The voice coil actuator 24 will exert a closing force to
the exhalation valve equal to the predetermined PEEP pressure. The
PEEP pressure is measured by the airway pressure sensor 31. The
controller 3 will activate the voice coil actuator 24 when the
expiratory airway pressure has reached the predetermined level.
[0132] In operation of the resuscitator shown in FIGS. 1 and 2, the
tidal volume delivered to the patient can be preset by the
controller 3 or the display panel 4. The tidal volume is controlled
by the stroke length of the piston 10. Tidal volume is delivered to
the patient on the compression stroke of the piston 10 and
exhalation for the patient is facilitated during the retraction
stroke of the piston 10. Accordingly one inhale and exhale of the
patient occurs during a movement of the piston 10 from one starting
point to its opposite end travel and back to the starting point.
For a given cylinder size, the longer the stroke of the piston, the
greater the tidal volume.
[0133] The controller 3 instructs the motor 13 to move the piston
10 a predetermined distance at a predetermined velocity.
[0134] Feedback from the airway pressure sensor 31 and a flow and
tidal volume sensor 36 can provide further control. These sensors
may vary normal operation of the piston 10 and/or voice coil
actuator 24 from conditions of operation predetermined by an
operator and instructed to the device via the display panel 4
and/or controller 3. The stroke length and position of the piston
10 may in addition be monitored by a sensor (a piston position
sensor) of or associated with the motor 13 and/or piston 10. The
operation of the resuscitator will control the breath rate and
inhalation/exhalation ratio. This can be preset by using the
controller and/or display panel and may be controlled at least in
part by a timer of the controller. Patient dependent parameters may
also control operation. For example, input information into the
controller 3 may include a patient's weight and age.
[0135] In a situation where the airway pressure sensor 31 senses
that the maximum predetermined airway pressure has been reached,
the controller 3 can instruct the motor 13 to slow or stop. This
can result in a maintaining of the maximum predetermined airway
pressure for the duration of the inhalation time period. In the
event of an overpressure or system failure, a safety valve 37 may
be actuated to open and relieve pressure on the patient airway. The
safety valve 37 may be a passive valve that has predetermined
operating conditions. Alternatively it may be a safety valve
connected with the controller 3 and controlled by the controller
for operation. Alternative to the safety valve 37, the airway
pressure sensor 31 and/or flow and tidal volume sensor 36 may
communicate with the controller 3 to direct movement of the voice
coil actuator in instances where undesirable conditions are being
sensed to thereby relieve pressure and/or flow by exhausting gas
through the opening 29.
[0136] This first form of resuscitator described as well as the
form yet to be described allows for data from the airway pressure
sensor 31, the piston position sensor, the flow and tidal volume
sensor 36 and from a timer to be used to record operating data and
performance. A graphical display on the display panel 4 can also be
generated. The graphical display can be used by the operator to
monitor performance and determine if leakage, blockage or further
adjustments are required to the resuscitator. The graph and/or
related data can be stored to assist in the setup of other life
support systems and for clinical analysis. Such statistical
information may offer significant benefits to future
situations.
[0137] The electrical connection 15 will ensure that the controller
3 can appropriately control the linear motor to thereby control the
position and movement of the piston. The cylinder 11 has an inlet
volute 16 that includes a primary inlet 17. It is through the
primary inlet that ambient air may be drawing into the inlet volute
as the piston displaces inside the cylinder towards the outlet 12.
This direction of travel is shown in FIG. 1. The piston 10 carries
a one-way valve 18 that operates to be in a closed condition when
the piston is travelling towards the outlet 12. This will result in
a drawing of ambient air into the inlet volute 16. When the piston
10 travels in the opposite direction being an exhalation direction
of the resuscitator, the one-way valve 18 can open to allow for air
in the inlet volute 16 to displace into the region between the
piston 10 and the outlet 12 as for example shown in FIG. 2. The
primary inlet 17 may include a one-way valve to assist such
displacement through the opening created by the one-way valve
through the piston by preventing air in the inlet volute 16 from
displacing back out through the primary inlet 17. The gas that has
displaced into the space between the piston 10 and the outlet
opening 12 can then on the return stroke during the inhalation
phase of operation be displaced at least in part through the outlet
opening 12 and to the flow control unit 7.
[0138] The resuscitator may (for example shown in FIG. 3) operate
in a supplementary oxygen and C-pap mode. A supplementary oxygen
reservoir 40 (that may or may not be connected to supplementary
supply via the inlet 41) can be engaged to the primary inlet 17 of
the pump unit 6. Rather than drawing ambient air into the pump
unit, the oxygen or other gas or gas mixture can be supplied to a
patient via the resuscitator. This will allow the operator to
control the delivery of an air/oxygen mixture by the use of for
example an external blender. Supplementary gas such as oxygen may
be delivered via the primary inlet 17 to the pump unit, under
pressure. In the event of a failure or the gas supply exceeding the
capabilities of the resuscitator, then a safety valve 42 may open
to exhaust gas from at least part of the pump unit 6. A pressure
sensor may be located in an appropriate location for these
purposes. If a failure occurs with the supplementary gas supply or
the primary inlet 17 becomes blocked then a safety valve 43 may
open to allow for ambient air to be drawn into the pump unit 6
allowing ongoing operation of the resuscitator despite issues with
the supply of supplementary gas.
[0139] In a C-pap mode operational conditions can be specified and
preset by using the controller and/or display panel. Where the
delivery rate and pressure to the supplementary gas reservoir 40 is
set at an appropriate flow level, the ventilator can operate in the
C-pap mode. The motor 13 will stop operation and the flow from the
supplementary oxygen reservoir 40 will pass through the one-way
valve 18 through the one-way valve 21 to the patient interface 8.
The airway pressure sensor 31 will determine the patient's airway
pressure. When the predetermined C-pap pressure has been reached
the voice coil actuator 24 will exert a closing force to the
exhalation valve to the predetermined C-pap pressure.
[0140] With reference to FIG. 4 there is shown a variation to the
resuscitator described with reference to FIGS. 1-3 wherein a
flexible conduit 56 is provided to extend between the pump unit 6
and the flow control unit 7. The flexible conduit 56 may be fitted
between the pump unit and the flow control unit to allow for
delivery for gas displaced by the piston 10 towards the patient
interface 8. Having the flow control unit 7 and airway pressure
sensors and tidal volume sensors as well as the safety valve 37
close to the patient's airway, ensures a more accurate tidal volume
and pressure delivery. Also the controller can make adjustments for
the compliance in the patient mask. Also possible but less
advantageous is to provide a conduit 9 that is of a desired length
to allow for more distal location between the patient interface 8
and the pump unit 6. However this has the disadvantage of dead
space between the features of the flow control unit 7 and the
patient interface 8.
[0141] The resuscitator of FIGS. 1-4, wherein the piston is single
acting, lends itself particularly to resuscitation and ventilation
of neonatal patients. A manageable sized pump unit can be provided
wherein in one stroke of the piston a sufficient tidal volume of
air can be delivered to a neonatal patient for inhalation. It is
desirable for the unit to be relatively portable and therefore size
can be a design constraint. However where size is not an issue, the
pump unit 6 can be scaled up so that single compression stroke of
the piston can deliver a sufficient tidal volume of gas to larger
patients. However this will increase at least the size of the pump
unit 6 making it less convenient for portability purposes.
[0142] An alternative configuration of resuscitator may be utilised
where size can be smaller. This resuscitator is shown for example
in FIG. 5. The resuscitator 101 includes a patient interface 108,
flow control unit 107 and related components that are preferably
the same as those described with reference to the resuscitator of
FIGS. 1-4.
[0143] This alternative form of resuscitator also includes a pump
unit 106. The pump unit 106 varies to the pump unit 6 described
with reference to FIGS. 1-4. There is provided a motor 113 such as
a linear motor or servo motor controlled by a controller 103 that
may be engaged with a display panel 104. The linear motor operates
a piston 110 via a connection such as a connection rod 114 that
operates in a cylinder 111. The pump unit 106 includes an inlet
volute 116. The inlet volute via a primary inlet 117 can draw air
or supplementary gas supply therethrough as a result of the action
of the piston and into the inlet volute 116.
[0144] The cylinder includes two openings capable of being in
communication with the inlet volute 116. A first opening 160 is
provided on the extension side of the piston 110. A second opening
161 is provided on the retraction side of the piston 110. The
opening 160 is closable by a one-way valve 162. The opening 161 is
closable by a one-way valve 163. The one-way valve 162 is able to
assume an opening condition during the retraction stroke of the
piston and is in a closed condition during the extension stroke of
the piston. The one-way valve 163 is able to assume an open
position during the extension stroke of the piston and is in a
closed condition when the piston is retracting. On the extension
side of the piston 110 is an outlet opening 164 of the cylinder
111. The outlet opening is closable by a one-way valve 165. The
one-way valve 165 is in a closed condition during the retraction
stroke of the piston and is able to assume an open condition during
the extension stroke of the piston. The one-way valve 165 hence
essentially works in an opposite mode to the one-way valve 162 to
the cylinder. The outlet opening 164 is able to create a fluid
connection of that part of the cylinder on the compression side of
the piston with an outlet volute 166. The outlet volute 166
includes an outlet opening 112 through which gas displaced by the
piston can pass to the flow control unit 7. The outlet volute 166
is separated from the inlet volute 116. The housing of the pump
unit 106 may include both the inlet volute 116 and outlet volute
166 and partitions 167 and the cylinder 111 may separate the
volutes. On the retraction side of the piston 110 the cylinder
includes an opening 168 to the outlet volute 166. The opening 168
includes a one-way valve 169. The one-way valve is positioned so
that during the retraction stroke of the piston, gas can displace
on the retraction side of the cylinder through the one-way valve
169 into the outlet volute 166. The one-way valve 169 will assume a
closed condition during the extension stroke of the piston 110.
[0145] In operation during the extension stroke of the piston as
shown in FIG. 6, the one way valve 163 opens allowing for air to be
drawn into the retraction side of the cylinder. Air on the
extension side of the piston during the extension stroke can be
displaced through the one-way valve 165 to be delivered into the
outlet volute. One-way valve 169 will be closed thereby only
offering one outlet to the outlet volute 166 being the outlet 112.
During the extension stroke of the piston the retraction side of
the cylinder is charged with gas being drawn through the one-way
valve 163. When the piston travels in its retraction stroke as
shown in FIG. 7, gas that has been drawn into the retraction side
of the cylinder may then be displaced through the one-way valve 169
into the outlet volute 166. The one-way valve 163 will close during
the retraction stroke thereby creating only one outlet from the
cylinder on its retraction side, namely the opening to discharge
the gas into the outlet volute 166. During the retraction stroke
the one-way valve 165 is closed thereby offering only one outlet
for gas being delivered into the outlet volute, namely being the
outlet opening 112. During the retraction stroke the extension side
of the cylinder is charged with gas from the inlet volute 116 via
the one-way valve 162 that is in that condition opened. As can be
seen the pump unit 106 hence operates in a double acting manner.
Both during the extension and retraction stroke of the piston gas
is displaced towards the opening 112 for delivery towards the
patient. With the use of a linear motor or servo motor having high
frequency capabilities and accurate and immediate start and stop
timing, a high frequency operating piston can deliver gas to the
patient in effectively a continuous manner during both the
retraction and extension strokes. Each tidal volume delivered to
the patient may involve a high number of strokes of the piston.
This allows for a compact and preferably portable unit to be
provided. Upon exhalation of the patient the flow control unit 107
may be operated to open the exhaust valve to allow for exhalation
to occur may coincide with the linear motor stopping operation.
Alternatively the linear motor may continue oscillating the piston
but where a waste valve may be opened to discharge displaced air
from the piston from reaching the flow control valve. Alternatively
such wasting may occur via the exhaust valve of the flow
control.
[0146] With reference to FIG. 8 the resuscitator described with
reference to FIGS. 5-7 is also capable of operating in a
supplementary gas and/or C-pap mode. This is shown for example in
FIG. 8. Furthermore an extension conduit 156 may be utilised as
shown in FIG. 9.
[0147] The number of oscillations that the piston may run through
can be predetermined. The oscillations determine the tidal volume
that is delivered to the patient. An operator may interact with the
control unit and/or display to set parameters of operation of the
resuscitator. Like the resuscitator described with reference to
FIGS. 1-4 stroke length and position of the piston as well as
airway pressures and tidal volume flow and volume sensing may occur
and be recorded and displayed.
[0148] The airway pressure may be monitored by a pressure sensor.
When the pressure sensor senses that the maximum predetermined
airway pressure has been reached the controller then instructs the
linear motor to stop or slow to maintain the maximum predetermined
airway pressure for the duration of the inhalation period.
Alternatively the controller may instruct the linear motor to stop
to reduce pressure. In the event of any over pressure or system
failure a safety valve like that described with reference to FIGS.
1-4 may open.
[0149] The voice coil actuator may be preloaded so that the exhaust
port tends to an open biased condition allowing external air to
enter the patient airway.
[0150] The resuscitator of FIGS. 5-9 may also operate in a PEEP
mode as previously described. In the C-pap mode of operation all
one-way valves to the cylinder are opened. This allows for direct
transfer of gas from the inlet volute 116 to the outlet volute 166
and to the patient. Pressure sensors and relief valves may be
included for failsafe purposes.
[0151] With reference to the resuscitators in FIGS. 1-9, parts of
the resuscitator may be disposable. In particular those parts of
the resuscitator that have been exposed to exhaled breath or air
from a patient may be disposable. They may be manufactured and
assembled in a way to facilitate their disposable use. For example
the patient interface 8, the flow control unit 7 and one way valve
21 and/or the voice coil actuator 24, movable mouth 23 and housing
22 may all be disengageable from the pump unit 6 and be disposed
after use. Circuits to allow for a quick connection of the
controller 3 to a replacement assembly of such parts may be
provided through simple plug/socket arrangement(s). A single
plug/socket may be provided. This may automatically become coupled
upon the engagement of the disposable components with the pump unit
6.
[0152] With reference to FIGS. 10 and 11 there is shown more detail
in respect of the tidal volume and flow sensor. In FIG. 10 there is
shown the patient interface 208 wherein the flow and tidal volume
sensor 236 is shown during the inhalation phase of operation. It is
connected to the controller 203 via a connection 283. With
reference to FIG. 11, the sensor 236 is shown in the exhalation
phase. The sensor 236 is of a kind that displaces dependent on air
flow past it. Such may not be ideal for accurate sensing due to
inertial mass of the sensor.
[0153] An alternative form of a sensor is one that has no inertial
mass delay characteristics. An alternative form of sensor that may
be used may be a gas flow meter that measure flow thermally. An
example of such a flow meter is one manufactured by Sensirion.com
such as their digital gas flow sensor ASF1400/ASF/1430. It may be
one that is made in accordance to that described in U.S. Pat. No.
6,813,944. Such a flow sensor has a high response rate, given that
it has unlike the sensor of FIG. 10, it has no mass to be displaced
by the flow. A fast response can be beneficial. Such sensors may
commonly be referred to as a hot wire flow sensor or thermal mass
flow meters. The sensor or an alternative sensor may also measure
the temperature of the exhaled breath. With an appropriate sensor
where the response rate is very quick (a matter of, for example one
tenths of a second) it is possible during the exhale of a patient
to measure the patient's core temperature.
[0154] This information may also be collected and/or displayed or
otherwise used by the resuscitator.
[0155] The invention may offer the advantages of being portable,
hand held (including being able to be held by one hand in order to
hold the patient interface in the appropriate condition) and self
contained by virtue of including its own power source (such as a 12
v power supply).
[0156] The device may have programmable profiles fixed and/or
customised to suit patients, clinicians and operators
requirements.
[0157] A heart rate monitoring facility may also be incorporated
with the device, wherein heart rate can be accounted for in the
control of the device and be displayed by the device.
[0158] The display can assist the operator in evaluating
resuscitation of the patient. The performance, operating parameters
and status of the features of the device are able to be recorded.
This can assist in statistical analysis and to gather information
for set-up of other devices.
[0159] The patient as herein defined may a mammal such a person or
animal.
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