U.S. patent application number 12/959447 was filed with the patent office on 2011-03-24 for bed exit alarm of hospital bed mattress.
Invention is credited to Jean-Marie Basilio, Gilles Camus, Thierry Flocard, Jean-Louis Viard.
Application Number | 20110068932 12/959447 |
Document ID | / |
Family ID | 39402847 |
Filed Date | 2011-03-24 |
United States Patent
Application |
20110068932 |
Kind Code |
A1 |
Flocard; Thierry ; et
al. |
March 24, 2011 |
BED EXIT ALARM OF HOSPITAL BED MATTRESS
Abstract
A mattress system includes a mattress, a control unit spaced
from the mattress, and a connector assembly that pneumatically and
electrically interconnects the control unit with the mattress. The
control unit has a main housing and a plurality of user interface
modules that are selectively coupleable to the control unit and
that are programmed differently to provide different modes of
operation for the mattress system. A pressure sensor inside the
mattress detects the presence or absence of a person on the
mattress. The mattress system has a bed exit alarm system that,
when armed, provides a bed exit alarm if the pressure sensor in the
mattress detects that a patient has exited the mattress. The
connector assembly includes a dual mode connector having both
electrical and pneumatic couplers and a dual lumen hose assembly
that extends from the dual mode connector to the mattress.
Inventors: |
Flocard; Thierry;
(Montpellier, FR) ; Camus; Gilles; (Montpellier,
FR) ; Basilio; Jean-Marie; (Meze, FR) ; Viard;
Jean-Louis; (Grabels, FR) |
Family ID: |
39402847 |
Appl. No.: |
12/959447 |
Filed: |
December 3, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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11559529 |
Nov 14, 2006 |
7849545 |
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12959447 |
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Current U.S.
Class: |
340/573.4 ;
5/713 |
Current CPC
Class: |
A61B 5/6891 20130101;
A61B 5/1117 20130101; A61G 7/05776 20130101; A61G 2203/34 20130101;
A61B 5/7475 20130101 |
Class at
Publication: |
340/573.4 ;
5/713 |
International
Class: |
G08B 23/00 20060101
G08B023/00; A61G 7/05 20060101 A61G007/05; A47C 27/14 20060101
A47C027/14 |
Claims
1. A mattress system comprising a mattress including at least one
inflatable bladder and a pressure sensor situated within an
interior region of the mattress, and a control unit spaced from the
mattress and having circuitry that receives a signal from the
mattress which is indicative of a pressure sensed by the pressure
sensor, the circuitry using the signal to establish at least one
target pressure to which the at least one inflatable bladder is
controlled and the circuitry also using the signal to determine
whether to activate a bed exit alarm.
2. The mattress system of claim 1, wherein the pressure sensor
comprises a bag filled with silicon oil.
3. The mattress system of claim 2, wherein the mattress comprises
an inflatable underlay having a space that receives the bag filled
with silicon oil.
4. The mattress system of claim 1, wherein the at least one
inflatable bladder comprises at least one inflatable layer that
overlies the pressure sensor.
5. The mattress system of claim 4, wherein the at least one
inflatable layer comprises first and second inflatable layers that
overlie the pressure sensor.
6. The mattress system of claim 5, wherein the first inflatable
layer comprises a plurality of laterally extending air bladders, at
least two of which are inflatable to different pressures, and the
second inflatable layer extends approximately the full length of
the mattress and is inflatable to a single target pressure.
7. The mattress system of claim 1, wherein the bed exit alarm
comprises a flashing light that is carried by the control unit.
8. The mattress system of claim 1, wherein the bed exit alarm
comprises a sound-producing device carried by the control unit.
9. A mattress system comprising a mattress having at least one
inflatable bladder, at least one electrical component situated
within an interior region of the mattress, a first pneumatic port
in communication with the at least one inflatable bladder, and a
first electrical connector in communication with the at least one
electrical component, a control unit spaced from the mattress and
comprising a main housing, a source of pneumatic pressure carried
by the main housing and operable to inflate the at least one
inflatable bladder, and circuitry programmed to control the manner
in which the at least one inflatable bladder is inflated, the
circuitry including a second electrical connector, the control unit
including a second pneumatic port in communication with the source
of pneumatic pressure, and a connector assembly to pneumatically
connect the first pneumatic port with the second pneumatic port and
to electrically connect the first electrical connector with the
second electrical connector, the connector assembly including a
pneumatic line, at least one electrical line, and a dual mode plug
configured to permit connection of the pneumatic line with the
second pneumatic connector substantially simultaneously with
connection of the at least one electrical line with the second
electrical connector.
10. The mattress system of claim 9, wherein the connector assembly
includes a dual lumen hose having side-by-side first and second
lumens, the first lumen serves as the pneumatic line for
communication of pneumatic pressure from the second pneumatic port
of the control unit to the at first pneumatic port of the mattress
and the second lumen serves as an electrical conduit through which
the at least one electrical line is routed.
11. The mattress system of claim 10, wherein a first end of the
dual lumen hose is coupled to the dual mode plug, wherein the
connector assembly has a pneumatic coupler mounted to the first
lumen at a second end of the dual lumen hose, and wherein the at
least one electrical line extends beyond the second lumen at the
second end of the dual lumen hose.
12. The mattress system of claim 9, wherein the dual mode plug
includes a plug housing and at least one latch member coupled to
the plug housing, the at least one latch member being movable
between a first position locking the dual mode plug to the main
housing of the control unit and a second position unlocking the
dual mode plug for detachment from the main housing of the control
unit.
13. The mattress system of claim 12, wherein the at least one latch
member is spring-biased toward the first position.
14. The mattress system of claim 12, wherein the at least one latch
member comprise a pair of latch members, each situated on an
opposite side of the plug housing.
15. The mattress system of claim 14, wherein the plug housing
includes a pair of recesses and at least a portion of each latch
member is received within a respective one of the pair of
recesses.
16. The mattress system of claim 14, wherein the pair of latch
members are movable toward the plug housing to move the pair of
latch members between the respective first and second
positions.
17. The mattress system of claim 9, wherein the dual mode plug
includes a front wall, a pneumatic coupler extending away from the
front wall, and an electrical coupler extending away from the front
wall; wherein the pneumatic coupler is configured to mate with the
second pneumatic port; and wherein the electrical coupler is
configured to mate with the second electrical connector.
18. The mattress system of claim 17, wherein the pneumatic coupler
is formed integrally with the front wall and the front wall has an
aperture through which the electrical coupler extends.
19. The mattress system of claim 17, wherein the dual mode plug
includes a check valve in communication with the pneumatic
coupler.
20. A mattress system comprising a mattress having at least one
person support element, a pressure sensor situated within an
interior region of the mattress, the pressure sensor being situated
beneath the at least one person support element and comprising an
enclosure containing a liquid, and circuitry that receives a signal
from the pressure sensor and that determines, based on the signal,
whether a bed exit condition has been detected.
21. The mattress system of claim 20, wherein the at least one
person support element comprises at least one foam element.
22. The mattress system of claim 20, wherein the at least one
person support element comprises a plurality of foam elements.
23. The mattress system of claim 20, wherein the at least one
person support element comprises at least one foam element and at
least one inflatable bladder.
24. The mattress system of claim 20, wherein the liquid contained
in the enclosure comprises a silicon oil.
25. The mattress system of claim 20, wherein the liquid contained
in the enclosure fills substantially all of an interior region of
the enclosure.
26. The mattress system of claim 20, wherein the enclosure
comprises a flexible bag.
27. The mattress system of claim 20, wherein the mattress further
comprises an underlay that is situated beneath the at least one
person support element and that has a space which receives the
enclosure containing the liquid.
28. The mattress system of claim 20, wherein the circuitry includes
a sound-producing device that is activated if the circuitry
determines that a bed exit condition has been detected.
29. The mattress system of claim 20, wherein the circuitry is
positioned within the mattress.
30. The mattress system of claim 20, further comprising a control
unit having a housing spaced from the mattress, the circuitry is
carried by the housing, and the pressure sensor is operably coupled
to the circuitry.
31. The mattress system of claim 30, wherein the pressure sensor is
operably coupled to the circuitry via at least one electrical line
that extends from the mattress to the control unit.
32. The mattress system of claim 30, wherein the pressure sensor is
operably coupled to the circuitry via a wireless coupling.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of U.S. application Ser.
No. 11/559,529, filed Nov. 14, 2006, which issued as U.S. Pat. No.
7,849,545 on Dec. 14, 2010 and which is hereby incorporated by
reference herein.
BACKGROUND OF THE INVENTION
[0002] The present disclosure relates to hospital bed mattresses
and particularly, to control systems for hospital bed mattresses in
which portions of the control systems may control inflation of one
or more air bladders included in the mattresses and portions of the
control systems may control bed exit alarms. The present disclosure
also relates to hose assemblies that interconnect control units
with associated mattresses.
[0003] Hospitals use a variety of different mattress types to
support patients having different medical needs. Some patients
benefit from being supported on alternating pressure mattresses or
rotation therapy mattress. Other patients may not need to be
supported on these types of mattresses having dynamic therapies,
but rather, so-called static air mattresses that simply operate to
provide a relatively low interface pressure may be suitable for
such patients. To address these various mattress requirements,
manufacturers may market a number of mattress products, each with
its own particularized therapeutic function, or may market
mattresses that have control units allowing users to program or
select different modes of operation. It can be expensive for
hospitals or other healthcare institutions to purchase a large
number of mattresses, each having its own dedicated therapeutic
functionality. However, mattresses allowing user selectable
functionality introduce the possibility that users may
inadvertently configure the mattress with the wrong type of therapy
or operation among the plurality of the available therapies.
[0004] It is sometimes desirable for patients to remain in bed and,
in such situations, hospitals are interested in having some type of
bed exit alarm for these patients to provide an alarm or alarm
signal indicating that the patient has exited, or is about to exit,
the bed. Some bed frames have built-in bed exit alarm systems,
oftentimes using the load cells of a weigh scale system, to
determine the presence or absence of a patient on the bed and
triggering a bed exit alarm when a threshold amount of weight is
determined to have been removed from the bed. The addition of a
weigh scale system to a bed frame adds cost and therefore,
hospitals purchase many bed frames without the weigh scale system
option and consequently, therefore, without any bed exit alarm
capability. Separate bed exit systems having strips or mats that
are placed on top of a mattress and underneath a patient are known
in the art, but such strips or mats may result in increased
interface pressure on the patient and thus, may compromise the
ability of the mattress to support the patient with relatively low
interface pressure.
SUMMARY OF THE INVENTION
[0005] The present invention comprises an apparatus or system
having one or more of the features recited in the appended claims
and/or one or more of the following features, which alone or in any
combination may comprise patentable subject matter:
[0006] A mattress system may comprise a mattress having at least
one inflatable bladder and a control unit. The control unit may
comprise a main housing, a source of pneumatic pressure carried by
the main housing and operable to inflate the at least one
inflatable bladder, and a plurality of user interface modules that
are coupleable to the main housing. Each user interface module may
be programmed to control inflation of the at least one air bladder
differently in at least one operational mode of each of the
plurality of user interface modules.
[0007] The user interface modules may include an alternating
pressure module and a continuous low pressure module. Additionally
or alternatively, the user interface modules may include a rotation
therapy module. One or more the user interface modules may be
programmed to provide two different types of therapies. Each of
user interface modules may have user inputs that are used to change
a mode of operation of the associated user interface module. One or
more of the user interface modules may be programmed to provide a
maximum inflation mode in which the at least one inflatable bladder
is inflated to a maximum threshold pressure which renders the at
least one air bladder suitably hard for patient transfer. One or
more of the user interface modules may include at least one visual
indicator that is operable to provide visual indication of the
operational status of the mattress system.
[0008] The control unit may have a latch coupled to the main
housing and movable between a locked position in which a selected
one of the plurality of user interface modules is locked to the
main housing and an unlocked position in which the selected one of
the plurality of user interface modules is detachable from the main
housing. The latch may have a hook and each of the user interface
modules may have a post that is captured by the hook when the
associated user interface module is locked to the main housing by
the latch. The main housing may have at least one slot and each of
the plurality of interface modules may have at least one tab that
is received in the slot provided in the main housing when the
associated user interface module is coupled to the housing.
[0009] Each of the user interface modules may comprise a main body.
The post and the at least one tab of each of the plurality of user
interface modules may be located on opposite ends of the associated
user interface modules. The post and the at least one tab of each
of the plurality of user interface modules may extend away from the
associated main body in opposite directions.
[0010] The main housing of the control unit may have a recess into
which each of the user interface modules is insertable. The control
unit may include a first electrical connector coupled to the main
housing. Each of the user interface modules may include a second
electrical connector that automatically mates with the first
electrical connector upon insertion of the user interface module
into the recess of the main housing.
[0011] At least one of the plurality of user interface modules may
have a lockout switch that is usable to lockout at least one
operational mode of the associated user interface module. The
lockout switch may be located adjacent a surface, such as a back
surface, of the associated user interface module that is
inaccessible to a user when the associated user interface module is
coupled to the main housing. The lockout switch may be used to
lockout the maximum inflation mode of the associated user interface
module.
[0012] One or more of the plurality of user interface modules may
include inputs that are engageable to enable a bed exit alarm
system of the control unit. The bed exit alarm system may receive
an input signal from the mattress indicative of a pressure sensed
by a pressure sensor situated in an interior region of the
surface.
[0013] The source of pneumatic pressure of the control unit may
comprise an air compressor within a noise-dampening housing that is
situated within an interior region of the main housing. The
noise-dampening housing may have an air chamber that serves as a
pressure reservoir which stabilizes air flow to the at least one
air bladder of the mattress.
[0014] The mattress may at least one valve located within an
interior region of the mattress. The valve may be opened and closed
to control pressure in the at least one inflatable bladder in a
manner dictated by the programming of the selected user interface
module that is coupled to the main housing. The mattress may have
at least one pressure sensor situated within an interior region of
the mattress and an output signal from the at least one pressure
sensor may be communicated to the selected user interface module
that is coupled to the main housing. At least one cardiopulmonary
resuscitation (CPR) input may be coupled to the mattress and may be
movable mechanically to deflate the at least one air bladder of the
surface. Movement of the CPR input may result in a CPR signal being
communicated to the selected user interface module that is coupled
to the main housing. The selected user interface module may
deactivate operation of the source of pneumatic pressure in
response to receiving the CPR signal.
[0015] The control unit may have circuitry that receives a signal
from the mattress which is indicative of a pressure sensed by a
pressure sensor situated within an interior region of the mattress.
The circuitry may use the signal to establish at least one target
pressure to which the at least one inflatable bladder is
controlled. The circuitry may also use the signal to determine
whether to activate a bed exit alarm. The bed exit alarm may
comprise a flashing light that is carried by the control unit.
Alternatively or additionally, the bed exit alarm may comprise a
sound-producing device, such as a speaker or buzzer, carried by the
control unit.
[0016] The pressure sensor may comprise a bag filled with silicon
oil. The mattress comprises an inflatable underlay having a space
that receives the bag filled with silicon oil. The at least one
inflatable bladder of the mattress may comprise at least one
inflatable layer that overlies the pressure sensor. The at least
one inflatable layer may comprise first and second inflatable
layers that overlie the pressure sensor. The first inflatable layer
may comprise a plurality of laterally extending air bladders, at
least two of which are inflatable to different pressures. The
second inflatable layer may extend approximately the full length of
the mattress and may be inflatable to a single target pressure.
[0017] The mattress may have one or more foam layers, blocks, pads,
and/or one or more other non-inflatable support elements in lieu
of, or in addition to, the at least one inflatable bladder.
Accordingly, the mattress may have no inflatable bladders at all. A
pressure sensor comprising an enclosure containing a liquid, such
as a bag filled with silicon oil, may be used as part of a bed exit
alarm system in such a foam mattress. With regard to mattresses
lacking any inflatable bladders, the control unit may be omitted
and the circuitry and sound-producing device of the bed exit alarm
system may be included within, or coupled directly to, the mattress
itself. In other embodiments, some or all of the circuitry and
sound producing device of the bed exit alarm system may be situated
in a housing or module that is spaced from the mattress and that is
coupled to the pressure sensor via one or more electrical lines, or
even wirelessly for that matter.
[0018] The mattress may have at least one electrical component
situated within an interior region of the mattress, a first
pneumatic port in communication with the at least one inflatable
bladder of the mattress, and a first electrical connector in
communication with the at least one electrical component. The
circuitry of the control unit may be programmed to control the
manner in which the at least one inflatable bladder is inflated.
The circuitry may also include a second electrical connector and
the control unit may include a second pneumatic port in
communication with the source of pneumatic pressure.
[0019] A connector assembly may be provided to pneumatically
connect the first pneumatic port with the second pneumatic port and
to electrically connect the first electrical connector with the
second electrical connector. The connector assembly may include a
pneumatic line, at least one electrical line, and a dual mode plug
configured to permit connection of the pneumatic line with the
second pneumatic connector substantially simultaneously with
connection of the at least one electrical line with the second
electrical connector.
[0020] The connector assembly may include a dual lumen hose having
side-by-side first and second lumens. The first lumen serves as the
pneumatic line for communication of pneumatic pressure from the
second pneumatic port of the control unit to the at first pneumatic
port of the mattress and the second lumen serves as an electrical
conduit through which the at least one electrical line is routed. A
first end of the dual lumen hose may be coupled to the dual mode
plug. The connector assembly may have a pneumatic coupler mounted
to the first lumen at a second end of the dual lumen hose. The
least one electrical line may extend beyond the second lumen at the
second end of the dual lumen hose.
[0021] The dual mode plug may include a plug housing and at least
one latch member coupled to the plug housing. The at least one
latch member may be movable between a first position locking the
dual mode plug to the main housing of the control unit and a second
position unlocking the dual mode plug for detachment from the main
housing of the control unit. The at least one latch member may be
spring-biased toward the first position. The at least one latch
member may comprise a pair of latch members, each situated on an
opposite side of the plug housing. The plug housing may include a
pair of recesses and at least a portion of each latch member may be
received within a respective one of the pair of recesses. The pair
of latch members may be movable toward the plug housing to move the
pair of latch members between the respective first and second
positions.
[0022] The dual mode plug may include a front wall. A pneumatic
coupler may extend away from the front wall and an electrical
coupler may extend away from the front wall. The pneumatic coupler
may be configured to mate with the second pneumatic port of the
control unit and the electrical coupler may be configured to mate
with the second electrical connector of the control unit. The
pneumatic coupler may be formed integrally with the front wall of
the dual mode plug and the front wall of the dual mode plug may
have an aperture through which the electrical coupler extends. The
dual mode plug may include a check valve in communication with the
pneumatic coupler.
[0023] Additional features, which alone or in combination with any
other feature(s), such as those listed above and those listed in
the claims, may comprise patentable subject matter and will become
apparent to those skilled in the art upon consideration of the
following detailed description of various embodiments exemplifying
the best mode of carrying out the embodiments as presently
perceived.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The detailed description particularly refers to the
accompanying figures in which:
[0025] FIG. 1 is an exploded perspective view of a mattress system
showing inflatable layers of a mattress of the mattress system
situated between top and bottom coverlets of the mattress and
showing a control unit situated near a foot end of the bottom of
the coverlet coupled electrically and pneumatically by a connector
assembly a technical box situated within an interior region of the
mattress;
[0026] FIG. 2 is a perspective view of the control unit of FIG. 1
showing a first user interface module being removed from a recess
formed in main housing of the control unit;
[0027] FIG. 3 is a front perspective of the first user interface
module of FIG. 2 showing user inputs on a front surface of the
first user interface module;
[0028] FIG. 4 is a front perspective of a second user interface
module that is coupleable to the main housing of the control unit
in lieu of the first user interface module;
[0029] FIG. 5 is a rear perspective of the second user interface
module showing a pair of tabs extending from one end of main body
of the module and a post extending from an opposite end of the main
body of the module and also showing a lock out switch that is
accessible on a rear surface of the main body when the module is
detached from the control unit;
[0030] FIG. 6 is rear perspective view of the control unit showing
a latch being movable in the direction of the arrow to unlock the
user interface module for detachment from the main housing of the
control unit;
[0031] FIG. 7a is a side elevation view of the control unit of FIG.
6, with portions broken away, showing the latch in an unlocked
position showing the post situated at an open end of a slot formed
in a hook or cam of the latch;
[0032] FIG. 7b is a side elevation view, similar to FIG. 7a,
showing the latch in a locked position such that the post of the
user interface module is captured within the slot of the hook;
[0033] FIG. 8 is a rear perspective view of the control unit
similar to FIG. 6 showing a dual mode plug of the connector
assembly coupled to a socket provided in a rear wall of the main
housing of the control unit and showing a coupling hook having a
cut out beneath the dual mode plug;
[0034] FIG. 9 is a perspective view of the connector assembly
showing a dual lumen hose having one end coupled to the dual mode
plug and having pneumatic and electrical couplers at an opposite
end thereof;
[0035] FIG. 10 is an exploded view of the dual mode plug at the end
of the connector assembly that couples to the control unit;
[0036] FIG. 11 is an enlarged perspective view of the end of the
connector assembly that couples to the mattress of the mattress
system;
[0037] FIG. 12 is an enlarged perspective view showing the
pneumatic and electrical couplers of the connector assembly coupled
to mating pneumatic and electrical connectors, respectively,
included in the mattress;
[0038] FIG. 13 is a diagrammatic view of the mattress system
showing a pressure sensor in a middle region of the mattress and
having associated sensor circuitry, a technical box at a foot end
of the mattress having valves and associated circuitry, and the
control unit with its associated circuitry;
[0039] FIG. 14 is a block diagram showing the logic implemented by
the circuitry of the mattress system to control a bed exit
alarm;
[0040] FIG. 15 is a block diagram showing the logic implemented by
the circuitry of the mattress system to control a lock out function
provided in each of the user interface modules;
[0041] FIG. 16 is a perspective view of the control unit of FIG. 1
showing a front shell of the main housing of the control unit
pulled away from a back shell of the main housing, a compressor
sub-housing situated in the lower region of the back shell, and
circuitry of the control unit situated in the back shell above the
compressor sub-housing.
DETAILED DESCRIPTION OF THE DRAWINGS
[0042] A mattress system 10 includes a mattress 12 and a control
unit 14 that is spaced-apart from the mattress 12 and that is
coupled pneumatically and electrically with the mattress 12 by a
connector assembly 16 as shown in FIG. 1. As is discussed in
greater detail below, the control unit 14 includes a plurality of
user interface modules 50, 52 that are able to be selectively
coupled to a main housing 18 of the control unit 14 to configure
the mattress system 10 with various functionalities depending upon
which of the user interface modules 50, 52 is coupled to the main
housing. For example, FIG. 3 shows a user interface module 50
having a primary mode of operation that is referred to as a
continuous low pressure mode and FIG. 4 shows a user interface
module 52 having a primary mode of operation that is referred to as
an alternating pressure therapy mode. The illustrative mattress
system 10 is available commercially and is marketed as the
ClinActiv.TM. Therapy Mattress System by Hill-Rom Company, Inc.
which is an affiliate corporation of the assignee of the present
application.
[0043] Illustratively, the mattress 12 includes an upper inflatable
bladder layer 20 having a plurality of laterally-extending cells or
bladders 22 which cooperate to define various zones of layer 20.
For example, a head section zone includes the first three cells 22
of layer 20. These three cells 22 are fluidly interconnected and
are illustratively regulated to the same pressure. The next ten
cells 22 form a torso section zone of layer 20. Finally, a heel
section zone includes the last seven cells 22 of layer 20 which are
fluidly interconnected with each other and are generally regulated
to a low target pressure. This target pressure is independent of
the rest of the zones of the layer 20 and is regulated by
electronics within the control unit 14.
[0044] When system 10 is operating in the continuous low pressure
mode, as dictated by module 50, the ten cells 22 of the torso
section zone are controlled to the same target pressure. However,
when system 10 is operating in the alternating pressure mode, as
dictated by module 52, a first group of five of the ten cells 22 of
the torso section zone are deflated for a period of time while a
second group of five of the ten cells 22 of the torso section zone
are inflated and then, after the period of time and after a dwell
time in which all ten cells 22 of the torso zone section are
inflated, the first group of five of the ten cells 22 of the torso
zone section are inflated for a period of time while the second
group of five cells 22 of the torso section zone are deflated for a
period of time. This sequence then repeats after another dwell time
in which all ten cells 22 of the torso section zone are inflated.
The cells 22 of the two groups of torso section zone cells 22 are
arranged such that each cell of the first group is situated between
adjacent cells of the second group, and vice versa, with the
exception of the cells that are the head end and foot end of the
torso section zone. In alternative embodiments, other cells of
layer 20 also inflate and deflate alternately in addition to the
alternating of the inflation and deflation of the cells 22 of the
torso zone section.
[0045] In the illustrative example, the head, torso, and heel
section zones of the layer 20 are controlled and operate
independently from one another. Further, while the various head,
torso, and heel section zones are described herein as including a
particular number of laterally-extending cells, it is within the
scope of this disclosure to include any number of independently
operable zones having any number of interconnected cells, and
having cells of any suitable size, shape, or orientation, including
cells that extend longitudinally.
[0046] The mattress 12 further includes a first air mattress
underlay 24 positioned below the layer 20 as well as a second air
mattress underlay 26 positioned below the first air mattress
underlay 24. Thus, underlay 24 serves as an intermediate layer
between layer 20 and underlay 26. Underlay 24 is a single
inflatable bladder but has internal walls or connections, such as
radio frequency welds between top and bottom sheets of the underlay
24, running in the longitudinal direction of mattress 12 to prevent
ballooning of underlay 24. Similarly, underlay 26 is also a single
inflatable bladder but has internal walls or connections running in
the lateral direction of mattress 12 to prevent ballooning of
underlay 26. In the illustrative embodiment, the first air mattress
underlay 24 and the second air mattress underlay 26 are
interconnected via conduits with each other and with the head
section zone of layer 20 and are inflated to the same pressure as
the head section zone of the layer 20. The mattress 12 further
includes a top coverlet 28 and a bottom coverlet 30 which are
coupled together by suitable couplers, such as one or more zippers,
to maintain the layer 20 and underlays 24, 26 within an interior
region of the mattress 12.
[0047] Layer 20 and underlays 24, 26 are inflatable patient support
elements of illustrative mattress 12. It should be appreciated that
the constructional details of elements 20, 24, 26 are merely
illustrative and mattress 12 may have inflatable elements of other
shapes, sizes, or orientations. Furthermore, mattress 12 may have
non-inflatable patient support elements, such as foam layers,
blocks, pads, and the like, as well as mesh materials, gel layers,
quilting, and the like, in lieu of or in addition to elements 20,
24, 26. Accordingly, mattresses having no inflatable elements at
all are within the scope of this disclosure.
[0048] The illustrative mattress 12 further includes a pressure
sensor 32 and a technical box 34 containing an air distribution
system 35 which includes a set of valves 37, associated circuitry
39, and a manifold assembly 33 in fluid communication with the
various cells 22 of layer 20 as well as with the first and second
air mattress underlays 24, 26 as shown diagrammatically in FIG. 13.
The manifold assembly 33 includes a pneumatic input and a plurality
of pneumatic outputs, each of which is associated its own valve of
the set of valves 37. In one embodiment, a first valve is in fluid
communication with the group of five bladders 22 of the torso
section zone while a second valve is in fluid communication with
the second group of five bladders 22 of the torso section zone. The
first and second sets of bladders 22 in the torso section zone are
arranged alternately and the first and second valves 37 are
controlled to inflate and deflate the first and second groups of
bladders 22 of the torso section zone alternately when mattress
system 10 is operating in the alternating pressure mode as dictated
by the programming of user interface module 52 as mentioned above.
If, on the other hand, user interface module 50 is coupled to the
main housing 18 of control unit 14, then the first and second
valves 37 are controlled so that all ten of the bladders 22 of the
torso zone section remain inflated simultaneously to the same
target pressure.
[0049] The set of valves 37 includes a third valve in fluid
communication with the heel zone of the layer 20 and a fourth valve
that is in communication with the head section zone of the layer
20, the first mattress underlay 24, and the second mattress
underlay 26. The valves 37 operate to open and close various
passageways of the manifold assembly 33 as is appropriate to allow
inflation or deflation of the associated groups of bladders of
mattress 12. In some embodiments, each of the valves 37 is a
three-way valve having an opened position allowing pressurized air
to be pumped to the associated bladders 22; a closed position
blocking air from being pumped to, and blocking air from escaping
from, the associated bladders 22 and underlays 24, 26; and a vent
position allowing air to vent from bladders 22 and underlays 24, 26
to atmosphere. In other embodiments, one more of the valves 37 are
two position valves and a separate vent valve is provided to vent
air from each of the various groups of bladders as needed. In some
embodiments, the valves 37 are solenoid valves. However, other
suitable valves, such as proportional control valves, may be used
if desired. The technical box 34 further houses circuitry 39,
referred to herein sometimes as the manifold printed circuit board
(PCB) for controlling the operation of the valves 37 within the
technical box 34. As is discussed in greater detail below, the
manifold PCB is in electrical communication with the control unit
14.
[0050] Illustratively, the pressure sensor 32 is positioned within
a cut-out section 36 formed in the second air mattress underlay 26
as shown in FIG. 1 while the technical box 34 is positioned at a
foot end of the mattress 12 such that foot ends of the air mattress
underlays 24, 26 generally abut the technical box but do not extend
over the top of the technical box 34. However, the layer 20 (and
particularly the heel zone bladders 22 of the layer 20) extends
over the technical box 34. When the mattress 12 is assembled, the
pressure sensor 32 of the mattress 12 is positioned generally below
the torso section zone of the layer 20 in order to sense the
pressure exerted by a patient on the torso section zone and provide
an output signal to the control unit 14 indicating the sensed
pressure.
[0051] Mattress 12 includes a cardiopulmonary resuscitation (CPR)
assembly that is coupled to the technical box 34 and that includes
a rotatable knob 40 that is accessible to the caregiver through an
aperture 42 formed in the foot end portion of the bottom coverlet
30. In normal operation, the CPR knob 40 is in a closed position.
When the CPR knob 40 is moved manually by a caregiver to an opened
position, air rapidly vents through the CPR assembly to atmosphere.
In addition, an electrical signal is provided by a switch or other
sensor to circuitry 39, the circuitry of control unit 14, and the
circuitry of sensor 32 to indicate that the CPR knob 40 has been
moved to the opened position. In response to this signal, control
unit 14 deactivates operation of the source of a pneumatic pressure
43, such as a compressor, of the control unit 14. A CPR indicator
light flashes on the control unit 14 and a CPR alarm sound beeps
regularly every 30 seconds to alert the caregiver that the CPR knob
40 has been activated. Once activated, the bladders of layer 20 and
underlays 24, 26 quickly deflate to provide a firm surface for
performing CPR on the patient lying atop the mattress 12.
[0052] Illustratively, the pressure sensor 32 of the mattress 12
comprises a liquid-containing flexible enclosure 45 and associated
circuitry 47 as shown in FIGS. 1 and 13. Enclosure 45 and circuitry
47 are both situated in the cut-out section 36 of underlay 26. In
some embodiments, the liquid-containing enclosure 45 comprises a
bag or bladder filled with a silicon oil, such as
polydimethylsiloxane. Circuitry 47 includes a pressure transducer
which is exposed to the fluid pressure in the bag via a conduit.
The transducer of circuitry 47 detects the pressure exerted upon it
by the liquid and relays a pressure signal to the control unit 14
via circuitry 47 and circuitry 39. The pressure sensed by the
transducer correlates to the amount of weight and pressure exerted
on enclosure 45, which correlates to the weight of the patient on
the mattress. As is discussed in greater detail below, circuitry
within the control unit 14 operates to establish the target
pressures of the zones of layer 20 and underlays 24, 26 and also
determines whether one or more zones of the layer 20 are to be
inflated or deflated based upon information received from the
pressure signal. The principles of operation of the pressure sensor
32 is described in greater detail in U.S. Pat. No. 6,094,762 which
is owned by the same assignee as the present application and which
is hereby incorporated by reference herein.
[0053] As mentioned above, the pressure sensor 32 is positioned
below the torso section zone of layer 20. Accordingly, as the
patient's torso applies pressure on the mattress 12, this pressure
is transferred as a force to the enclosure 45 of pressure sensor
32. The pressure in the enclosure 45 is detected by the transducer
of circuitry 47 and a pressure signal is sent to the control unit
14. Circuitry within the control unit 14 then determines whether to
vent air from the layer 20 and/or underlays 24, 26 of the mattress
12 or to turn on the pneumatic source 43 within the control unit 14
to inflate the layer 20 and/or underlays 24, 26 in order to reach
respective target pressures which are established by control unit
14 based on the signal received from sensor 32. Accordingly, the
target pressures of cells 22 of layer 20 and underlays 24, 26 of
the mattress 12 are adjusted automatically to accommodate each
individual patient's weight and position. In some embodiments, a
pressure comparator is provided in circuitry 47 to make a
comparison between the pressure in enclosure 45 and the pressure in
the head section zone bladders 22 of layer 20 and the underlays 24,
26 and then control unit 14 and valves 37 are operated to equalize
the pressure therebetween. In such an arrangement, any additional
pressure sensor to sense the pressure in head section zone bladders
22 of layer 22 and underlays 24, 26 may be omitted.
[0054] In some embodiments, additional pressure sensors 41 are
provided in technical box 34 and are associated with respective
pneumatic lines used to inflate layer 20 and underlays 24, 26. The
additional pressure sensors detect and communicate the pressure
within each zone of the layer 20 and within the underlays 24, 26 to
the control unit 14. Such measured pressures are compared with the
target pressure values established by the circuitry of control unit
14 based on the pressure signal originating from pressure sensor
32. In other embodiments, technical box 34 has only a single
pressure sensor 41 which is coupled sequentially, by appropriate
opening and closing of the various valves 37, to each of the zones
of layer 22 and to underlays 24, 26 to measure sequentially the
pressures in each of the zones.
[0055] The data from pressure sensor 32 is used in three distinct
operation modes of system 10 including stand-by regulation, patient
egress surveillance, and main zone pressure regulation. As is
discussed in greater detail below, the stand-by regulation mode
means that system 10 operates to achieve a relatively low pressure
in the mattress 12 so as to provide a ready-to-use, and yet
comfortable, support when the patient is initially placed on the
mattress 12. The patient egress surveillance mode means that system
10 operates to monitor the presence and absence of the patient on
the mattress 12. The main zone pressure regulation mode means that
system 10 operates to control the internal pressures in the
bladders 22 of layer 20 and underlays 24, 26. Illustratively, the
circuitry 47 of pressure sensor 32 is in electrical communication
with the circuitry 39 situated within the technical box 34. As
noted above, the circuitry 39 within the technical box 34 is in
electrical communication with the control unit 14 via the connector
assembly 16.
[0056] Referring now to FIGS. 2-6, the control unit 14 includes the
main housing 18, a source of pneumatic pressure 43 such as a pump,
blower, or compressor (shown diagrammatically in FIG. 13) contained
within the main housing 18, and first and second user interface
modules 50, 52 that are selectively coupleable to the main housing
18. The compressor 43 of the control unit 14 is enclosed in a
sub-housing 49, shown in FIG. 16, within the main housing 18 of the
control unit 14 to dampen noise while the compressor 43 is running.
Power is provided to unit 14 via a power cord 19, shown in FIG. 1,
which plugs into unit 14 and into a standard electrical outlet to
receive power therefrom. Illustratively, the sub-housing 49 is made
of aluminum; however, is should be understood that the sub-housing
49 may be made of other suitable materials to dampen the noise of
the compressor 43 contained therein. Further, an air chamber 51 of
the control unit 14 is positioned generally in top region of the
compressor sub-housing 49 in order to serve as a pressure reservoir
that stabilizes the air flow within the control unit 14 as well as
reduce noise output of the control unit 14.
[0057] Each of the first and second user interface modules 50, 52
are programmed to control inflation of the layer 20 and/or
underlays 24, 26 of the mattress 12 differently in various
operational modes of each of interface module 50, 52.
Illustratively, the front side of the main housing 18 includes a
recess 54 provided therein. The interface modules 50, 52 are each
selectively received within the recess 54 and are locked in place
by a latch 90 of the control unit 14, as is discussed in greater
detail below with regard to FIGS. 7a and 7b. The user interface
modules 50, 52 operate as the main caregiver controls of the
mattress system 10 while also providing feedback to the caregiver
as to the operational status of the system 10. Each of the modules
50, 52 includes circuitry that is programmed with instructions that
dictate the operational modes of system 10.
[0058] Referring to FIG. 3, the first user interface module 50
includes a user interface panel 55 having a front surface 56 and a
main body 57 that is coupled to the user interface panel 55 and
that has a rear surface 58. Illustratively, the first user
interface module 50 is a continuous low pressure (CLP) therapy
module. The CLP mode of the module 50 is automatically activated
when the CLP module 50 is placed in the recess 54 of the control
unit 14 and the main switch 53 of control unit 14 (see FIG. 16) is
switched on. Illustratively, the CLP module 50 and module 52 each
include an electrical connector 59 on the rear surface 58 of the
main housing 57 as shown in FIG. 5 with regard to module 52. The
electrical connector 59 is coupled to an electrical coupler 61,
shown in FIG. 2, within the recess 54 of the control unit 14 to
provide electrical communication between the module 50 and internal
circuitry 63, shown in FIG. 16, of the control unit 14. A ribbon
cable 65, also shown in FIG. 16, interconnects connector 61 and
circuitry 63.
[0059] During the CLP mode, the ten cells 22 in the torso section
of the layer 20 are regulated to the same target pressure (all
targets pressures referred to herein have associated tolerance
ranges as is well known in the art) as set by the pressure sensor
32. As mentioned above, the three head section cells 22 of the
layer 20, the first underlay mattress 24, and the second underlay
mattress 26 are fluidly interconnected with each other and are
inflated to the same pressure as the cells 22 of the torso section
of the layer 20 during the CLP mode. The seven foot section cells
22 of the layer 20 are regulated to a lower target pressure which
is determined independently of the rest of the mattress
sections.
[0060] Various user inputs and indicators are provided on the front
surface 56 of the user input panel 55 of the module 50 as shown in
FIG. 3. For example, an on/off button 58 is engaged by a user to
turn the module 50 on or off. A light indicator 60 illuminates to
denote that the module 50 has been turned on. Upon first connecting
the control unit 14 to the main power supply, the mattress system
10 operates to automatically inflate the layer 20 and underlays 24,
26 to a maximum inflation pressure value to fully expand the cells
22 and underlays 24, 26. The mattress system 10 then automatically
reverts to the therapy mode provided by the selected module 50 or
52 after approximately eight minutes. During start up, the
caregiver may press the on/off button 58 twice to override the
maximum inflation function, if desired.
[0061] An internal pressure indicator provides an indication of the
pressure variation in the torso zone of the layer 20. Segments of
the light indicator 62 will illuminate as the pressure within the
torso zone automatically varies. A maximum inflation (P-max) button
64 is engaged by user to inflate layer 20 and underlays 24, 26 to
the maximum inflation pressure at the user's discretion. Thus, the
maximum inflation button 64 may then be activated at any time in
order to inflate the layer 20 and underlays 24, 26 to the maximum
inflation pressure. Oftentimes, for example, a caregiver may use
the maximum inflate button 64 in order to provide a firmer patient
support surface for patient transfers or bedding changes.
Illustratively, pressing the maximum inflation button 64 a second
time will immediately end the maximum inflation mode and return the
mattress 12 to the therapy mode. The maximum inflation pressure is
a target pressure that is typically higher than the pressures to
which layer 20 and/or underlays 24, 26 are inflated during other
modes of operation of system 10 and it should be understood that
layer 20 and underlays 24, 26 are capable of withstanding even
higher pressures than the one referred to as the maximum inflation
pressure in this disclosure.
[0062] Pressing a bed exit alarm button 66 of the user interface
module 50 arms or enables a patient egress surveillance system
(sometimes referred to herein as a "bed exit system" or "bed exit
alarm system" or the like). As is discussed in greater detail
below, the pressure sensor 32 of the mattress 12 operates to detect
the presence and absence of a patient on the mattress 12 by sending
a pressure signal to the control unit 14. Circuitry of the control
unit 14 then determines, based upon the value of the pressure
signal, whether the patient is present on, or absent from, the
mattress 12. The determination regarding the presence of absence of
the patient is made by comparing the pressure sensed by sensor 32
with a threshold value. If it is determined that the patient is
absent from the mattress 12, an alarm to alert a caregiver is
activated if the bed exit alarm system is enabled. The alarm may be
a visual alarm such as a light indicator on the module 50 and/or
may be an audible alarm such as a beeping noise made by a
sound-producing device such as a speaker or piezoelectric buzzer,
for example. When the bed exit alarm function is enabled, a light
indicator 68 on the module 50 is illuminated.
[0063] An alarm silence button 70 of the module 50 may be engaged
by a user to temporarily silence any audible alarm associated with
the maximum inflation function, the CPR function, a power failure,
and/or a mattress malfunction. For example, when one or more of the
above-referenced alarms are sounding, the caregiver may press the
alarm silence button 70 to temporarily silence the sounding
alarm(s). The alarm(s) will then sound again after approximately 10
minutes if the condition causing the alarm is not rectified. The
alarm(s) may also be permanently silenced by pressing the alarm
silence button 70 until the light indicator 72 flashes. In some
embodiments, the alarm silence button 70 also may be engaged by the
user to silence a bed exit alarm.
[0064] A CPR light indicator 74 of the module 50 flashes when the
CPR function, discussed above, is activated. A seat cushion light
indicator 76 illuminates when an optional seat cushion (not shown)
of the mattress system 10 is being inflated. The indicator 76 turns
off after approximately five minutes once the seat cushion is
completely inflated. Illustratively, during inflation of the seat
cushion, the maximum inflation function is automatically activated
without audible indication. The seat cushion inflation may be
stopped at any time by pressing the maximum inflation button 64.
Once inflated, the seat cushion is disconnected from control unit
14 and remains inflated for use on a wheel chair or other type of
seating surface. A valve coupled to the seat cushion may be open to
allow deflation of the seat cushion to atmosphere.
[0065] A safety lock-out light indicator 78 of the module 50
illuminates whenever the user interface module 50 is locked-out to
prevent a patient or caregiver from adjusting the settings.
Illustratively, as shown in FIG. 5 with regard to module 52, the
rear surface of the module 50 and the module 52 each includes a
lock-out switch 80. The caregiver may move the lock-out switch 80
to an activated position in order to lock-out the controls of the
module 50 or the module 52, as the case may be, to prevent a
patient or other caregiver from tampering with the particular
settings of the module 50, 52, thereby to prevent intentional or
unintentional changes in the operating mode of system 10.
Illustratively, the lock-out switch 80 is located on the rear
surface 58 of the module 50, 52 and is, therefore, generally
inaccessible by the patient. The safety lock-out indicator 78 is
illuminated when the lock-out switch 80 has been activated.
Illustratively, the safety lock-out indicator light 78 will then
flash in the event of a control button being pressed in order to
signal that the user interface is locked-out.
[0066] To unlock the lock-out function, the caregiver removes the
module 50 from the housing 18 of the control unit 14 and moves the
lock-out switch 80 to the deactivated or unlocked position.
Alternatively, the caregiver may temporarily unlock the lock-out
function by removing the module 50 from the housing 18 and pressing
a lock-out button 81 adjacent the switch 80. Illustratively,
pressing the lock-out button 81 (while maintaining the switch 80 in
the activated position) operates to deactivate the lock-out
function for a predetermined period of time, such as 20 seconds,
for example. This function allows the user then to resecure the
module 50 to the housing 18 and manipulate the controls of the
module 50 without having to again remove the module 50 from the
housing to reinitiate the safety lock-out function. Once the
caregiver has manipulated the controls of the module 50, the
lock-out function will be automatically reactivated once the
predetermined period of time has elapsed.
[0067] A power failure light indicator 82 illuminates when the
control unit 14 is disconnected from the main power supply or in
the event of a power failure. The power failure light indicator 82
will also illuminate during transport. A mattress malfunction light
indicator 84 of module 50 illuminates in the event of a pressure
fault and a continuous low pressure (CLP) therapy indicator 86 of
module 50 illuminates to indicate that CLP therapy is being
used.
[0068] Illustratively, as noted above, an audible alarm is sounded,
as well as a visual indicator being illuminated, when the maximum
inflation function has been activated, when the CPR function has
been activated, when a patient has exited the bed (assuming the bed
exit alarm system is enabled), when the control unit 14 has been
disconnected from the main power supply or when a power failure has
occurred, and when a mattress defect is detected.
[0069] Referring now to FIG. 4, the second user interface module 52
similarly includes the user interface panel 55 having the front
surface 56 and the main body 57 having the rear surface 58.
Illustratively the second user interface module 52 is an
alternating pressure (AP) therapy module. The AP therapy mode is
automatically activated when the AP module 52 is placed within the
recess 54 of the main housing 18 of the control unit 14.
Illustratively, the AP mode affects the ten cells 22 within the
torso section zone of the layer 20 to sequentially inflate and
deflate every other cell 22 within the torso section zone.
Accordingly, none of the three head section cells 22 and none of
the seven heel section cells 22 are alternately inflated and
deflated in the illustrative embodiment, but may do so in other
embodiments.
[0070] As noted above, the pressure in the torso section cells 22
is controlled by the pressure sensor 32. Illustratively, the AP
mode may be described in three phases. In the first phase, five
non-adjacent cells 22 (forming a first AP zone of cells) in the
torso section zone of the layer 20 are deflated. This deflation
takes approximately four minutes. In the second phase, the pressure
in all the cells 22 within the torso section is the same (i.e., at
a continuous low pressure). The duration of the second phase is
approximately 1 minute. The purpose of the second phase of the AP
therapy mode is to enhance patient comfort by providing a soft
surface between the deflated phases. In the third phase, the other
five non-adjacent cells 22 (forming a second AP zone of cells) in
the torso section zone of the layer 20 are deflated. Similar to the
first phase, the third phase lasts approximately four minutes. A
similar discussion of the AP mode is presented above.
[0071] Various user inputs and indicators are provided on the front
surface 56 of the user input panel 55 of the module 52.
Illustratively, many of these user inputs are the same as those
discussed above with respect to the first user interface module 50.
As such, like reference numerals have been used to denote like
inputs and/or indicators. However, rather than including the CLP
indicator 86 of the module 50, the module 52 includes an
alternating pressure (AP) therapy indicator 88 to indicate that AP
therapy is being used.
[0072] Although the CLP user interface module 50 and the AP user
interface module 52 are provided in the illustrative examples, it
is within the scope of this disclosure for the mattress system 10
to include other user interface modules that are selectively
coupleable with the control unit 14 as well. For example, a
rotation therapy user interface module may provide a continuous
lateral rotation therapy (CLRT) function and a low air loss user
interface module may provide a low air loss function for cooling
the patient and/or wicking moisture away from the patient. Of
course, it should be understood that any number of user interface
modules having any number of therapy functions may be provided for
use with the control unit 14 and mattress 12 of the mattress system
10. Further, it is within the scope of this disclosure to include
more than one therapy function on a single user interface module.
For example, while each of the CLP and AP modules 50, 52 are
dedicated to a single therapy, a single user interface module may
be provided which includes both CLP and AP therapies. Accordingly,
any number and any combination of desired therapies may be provided
on a single user interface module. Each user interface module
includes circuitry that is programmed to implement its associated
functionalities. Thus, the programming of the various types of
modules is different. This provides a cost savings to healthcare
facilities because, to achieve different types of patient
therapies, only the associated user interface modules need to be
purchased rather than having to purchase an entirely different
mattress system.
[0073] Each of the user interface modules 50, 52 further includes a
locking post 92 extending from a first end of 94 the main body 57
of the respective module 50, 52, as shown in FIGS. 3 and 4.
Referring now to FIG. 5, a pair of tabs 96 of each user interface
module 50, 52 extend outwardly from a second end 98 of the main
body 57 of the respective module 50, 52. Thus, post 92 and tabs 96
extend from main body 57 in opposite directions. As is discussed
below, the locking post 92 and tabs 96 are used to secure the
respective modules 50, 52 within the recess 54 formed in the main
housing 18 of the control unit 14.
[0074] As noted above, the user interface modules 50, 52 may be
selectively attached to and removed from the main housing 18 of the
control unit 14. In order to attach one of the first and second
user interface modules 50, 52 to the main housing 18 of the control
unit 14, the caregiver slides the pair of tabs 96 of the selected
module 50 or 52 into corresponding slots 67, shown in FIG. 2 (in
phantom), formed in the main housing 18 of the control unit 14. In
the illustrative embodiment, the slots of the housing 18 are formed
in a side wall of housing 18 defining part of the recess 54. Once
the tabs 96 of the selected module 50 or 52 are received within the
corresponding slots of the housing 18, the main body 57 of the
selected module 50 or 52 may further moved into the recess 54 such
that the locking post 92 is received within a slot 97 defined by
hook portion 98 of a pivotable cam 99 coupled to the latch 90 to
further secure the selected module 50 or 52 within the housing 18.
Illustratively, as shown in FIGS. 7a and 7b, movement of the latch
90 in a first direction 101 operates to rotate the cam 99 in a
clockwise direction such that the slot 97 of the hook portion 98
captures the post 92 of the selected module 50 or 52 therein (as
shown in FIG. 7b).
[0075] In order to remove one of the first and second user
interface modules 50, 52 from the control unit 14, the caregiver
may rotate the latch 90 located at the rear side of the control
unit housing 18 in direction 103 shown in FIG. 7b from a first,
locked position to a second, unlocked position. Illustratively,
movement of the latch 90 in direction 103 operates to rotate the
cam 99 in a counterclockwise direction such that the post 92 of the
selected module 50 or 52 becomes disengaged from the slot 97 of the
hook portion 98 (as shown in FIG. 7a). When the latch 90 is in the
second, unlocked position, hook 98 of the cam 99 is disengaged from
the post 92 of the selected module 50 or 52 to allow the caregiver
to remove the particular user interface module 50 or 52 from the
main housing 18 of the control unit 14.
[0076] The shape of slot 97 is such that when latch 90 is rotated
in direction 101, with hook portion 98 capturing post 92, post 92
is pulled generally radially inwardly toward the pivot axis of
latch 90 to firmly seat the associated module 50, 52 against the
main housing 18 and to pull the electrical connectors 59, 61
together. On the other hand, when latch 90 is rotated in direction
103, with hook portion 98 capturing post 92, post 92 is pushed
generally radially outwardly way from the pivot axis of latch 90 to
unseat the associated module 50, 52 from housing and to push the
electrical connectors 59, 61 apart. After being unseated in this
manner, the module 50, 52 is far enough away from main housing 18
to provide space for a user to grasp the module 50, 52, as shown in
FIG. 7a with regard to module 50, and completely detach it from
housing 18.
[0077] Referring now to FIG. 8, the control unit 14 further
includes a socket 100 formed in a rear wall 102 of the main housing
18 as well as a bracket assembly or coupling hook 104 coupled to
the rear side 102 of the main housing 18. As is discussed in
greater detail below, the socket 100 of control unit 14 receives a
dual mode plug 110 of the connector assembly 16 therein.
Illustratively, the coupling hook 104 is positioned below the
socket 100 of the main housing 18 and is provided to allow a
caregiver to hang the control unit 14 on a footboard or side rail
of a bed frame, for example. Hook 104 has a cutout 101 to
accommodate the dual mode plug 110 and a user's fingers when
attaching the connector assembly 16 to, or detaching the connector
assembly 16 from, housing 18. The control unit 14 also includes
rubber pads (not shown) on a bottom surface of the main housing 18
in order to enable the control unit 14 to stand on a hard surface
as well.
[0078] Referring now to FIGS. 9-12, the connector assembly 16 of
the mattress system 10 provides a pneumatic and electrical
connection between the control unit 14 and the mattress 12. The
connector assembly 16 includes a dual lumen hose 118 including a
pneumatic line 120 for communication of pneumatic pressure from the
control unit 14 to the mattress 12 and an electrical line 122 that
serves as an electrical conduit through which electrical conductors
are routed between the control unit 14 and the mattress 12.
Illustratively, the pneumatic line 120 and the electrical line 122
are connected to each other and positioned side-by-side along a
majority of the length of the lines 120, 122, as shown in FIG. 9,
for example.
[0079] The connector assembly 16 further includes the dual mode
plug 110 at a first end of the dual lumen hose 118. The dual mode
plug 110 is received within the socket 100 of the main housing 18
in order to provide a substantially simultaneous pneumatic and
electrical connection with the control unit 14. Illustratively, the
dual mode plug 110 includes a plug housing 124 and two latch
members 126 coupled to respective sides of the plug housing 124. In
particular, the plug housing 124 includes a pair of recesses 127
formed in each side of the plug housing 124 such that a portion of
each latch member 126 is received within a respective recess 127.
Each of the latch members 126 are movable between a first position
locking the dual mode plug 110 to the main housing 18 of the
control unit 14 and a second position unlocking the dual mode plug
110 from the main housing 18 of the control unit 14.
Illustratively, the latch members 126 are spring-biased toward the
first position by respective springs 128, shown in FIG. 10.
Further, in order to move the latch members 126 between the first
and second positions, a caregiver squeezes each latch member 126 in
a direction generally toward the plug housing 124 and further
within the respective recesses 127.
[0080] Referring still to FIG. 10, the dual mode plug 110 further
includes a front wall 130 coupled to the housing 124, a pneumatic
coupler 132 extending away from the front wall 130, and an electric
coupler 134 that extends beyond front wall 130 through an aperture
133 formed therein. A first end of each of the electrical
conductors routed through line 122 is coupled to, and terminates
at, electrical connector 134. The control unit 14 includes an
electrical connector 107 (shown diagrammatically in FIG. 13) within
the socket 100 which is in communication with the internal
circuitry 63 control housing 14 and a pneumatic port 109 (also
shown diagrammatically in FIG. 13) within the socket 100 which is
in communication with the compressor 43 of the control unit 14.
Accordingly, when the dual mode plug 110 is received within the
socket 100 of the control unit 14, the pneumatic coupler 132 of the
plug 110 is coupled to the pneumatic port 109 of the control unit
14 and the electric coupler 134 of the plug 110 is coupled to the
electrical connector 107 of the control unit 14. Further, the dual
mode plug 110 is configured so that the electrical and pneumatic
connections between the connector assembly 16 and the control unit
14 are made substantially simultaneously.
[0081] A check valve 131 is provided within housing 124 of plug 110
and is in pneumatic communication with port 132. When plug 110 is
coupled to socket 100 and compressor 43 is operated, the check
valve 131 is opened to allow pressurized air to move through
pneumatic line 120. When plug 110 is disconnected from socket 100,
check valve 131 is closed to prevent air from escaping from
mattress 14 through connector assembly 16.
[0082] Latch members 126 each have a rearwardly projecting tab 111
that is captured within a rear pocket 121 of the respective recess
127 and a forwardly projecting tab 113 that extends through a
respective aperture 115 of front wall 130. Apertures 115 are
oversized in the lateral direction to allow movement of tabs 113
therein when latch members 126 move between the first and second
positions. Each latch member 126 also has a laterally inwardly
projecting tab 117 that is received in an associated slot 119
formed in a respective side of housing 124. Receipt of tabs 111,
113 in the associated pockets 121 and apertures 115 retains latch
members 126 in place within recess 127, whereas receipt of tabs 117
in slots 119 guides the lateral movement of latch members 126. Each
of latch members 126 further has a laterally outwardly projecting
tabs 123 that is received in associated tab-receiving recess or
pocket 125, shown in FIG. 8 (in phantom), formed in the sidewalls
of socket 100. Receipt of tabs 123 in recesses 125 locks plug 110
to the socket 100 of the housing 18 of the control unit 14. When
latch members 126 are squeezed toward housing 124 of plug 110, tabs
123 are withdrawn from recesses 125, thereby allowing plug 110 to
be disconnected from socket 100.
[0083] Referring now to FIGS. 9 and 11, the connector assembly 16
further includes a pneumatic coupler 140 mounted to the second end
of the pneumatic line 120 and an electrical connector 142 mounted
to an end of a cable 141 of the electrical conductors which exit
from the second end of the electrical line 122. As shown in FIG.
12, the pneumatic coupler 140 is coupled to a pneumatic port 144 of
the mattress 12. Specifically, the technical box 34 includes the
pneumatic port 140 which is in pneumatic communication with the
inflatable layer 20 and underlays 24, 26 of the mattress 12 via the
manifold assembly 35 within the technical box 34. Further, the
electrical connector 142 of the connector assembly 16 is coupled to
an electrical connector 146 of the technical box 34 of the mattress
12. The electrical connector 146 of the mattress 12 is in
electrical communication with the electrical circuitry 39, 47
within the mattress 12. Further illustratively, the technical box
34 includes a first pressure test port 150 for checking the
pressure in the torso zone of the layer 20 and a second pressure
test port 152 for checking the pressure in the heel zone of the
layer 20. Pressure transducers 41 of technical box 34 are coupled
electrically to test ports 150, 152 to provide feedback information
regarding the pressure within an associated zone of mattress
14.
[0084] In operation, air enters the control unit 14 through an air
filter (not shown) within the control housing 18 of the control
unit 14. The air then travels into the compressor inlet. Upon
exiting the compressor 43, the air travels through check valve 131
and the pneumatic line 120 of the connector assembly 16 and into
the manifold assembly 35 located in the technical box 34 within an
interior region of the mattress 12. The air is then dispatched
through valves 37 into the various inflatable mattress layers
including the layer 20, the first air mattress underlay 24, and the
second mattress underlay 26. In the illustrative embodiment, the
check valve 131 located inside plug 110 of the connector assembly
16 provides approximately four hours of inflation of the mattress
12 in the event the control unit 14 is disconnected from the main
power supply or if the dual lumen hose 118 is disconnected from the
control unit 14.
[0085] As mentioned above, each of modules 50, 52 is programmed to
provide system 10 with a bed exit alarm function. FIG. 14 is a
diagram which illustrates the logic of the bed exit alarm function
of system 10. Sensor 32 provides a signal to circuitry 47 which
measures the pressure exerted on sensor 32 as indicated at block
160. A comparator 162 receives the pressure measurement signal and
also receives a threshold setting signal which is represented by
block 164 in FIG. 14. In one embodiment, the threshold setting is
established for a minimum patient weight of fifty pounds but, in
other embodiments, other threshold settings may be established at
the discretion of the system programmer or designer.
[0086] If the pressure measurement signal is less than the
threshold value signal, which is an indication that the patient has
exited the mattress 14, then the output of comparator 162 is on
(e.g., a high logic state), otherwise the output of comparator 162
is off (e.g., a low logic state). If the comparator is turned on,
then system 10 automatically operates in the stand by mattress
pressure regulation mode in which layer 20 and underlays 24, 26 are
controlled to reduced pressure settings as indicated at block 166.
If the bed exit or patient egress alarm is enabled, as indicated at
block 168 and the comparator is on, then the output of an AND gate
170 is on. The output of AND gate 170 is input to another AND gate
172 which has a second input from a 1 Hertz (Hz) clock 174. Thus,
if the output of AND gate 170 is on, then the output of AND gate
172 will be a 1 Hz signal that is fed to patient egress alarm
indicator as indicated at block 176.
[0087] As mentioned above the bed exit alarm may include a visual
indicator, such as a light emitting diode (LED) and/or a sound
producing device, such as a speaker or buzzer. In the illustrative
embodiment, the 1 Hz signal being output from AND gate 172 will
cause the visual indicator to flash at a rate of 1 Hz and will
cause the sound producing device to beep at a rate of 1 Hz.
Although, logical AND gates 170, 172 are used in FIG. 14 to explain
the operation of the bed exit alarm function of system 10, it
should be appreciated that the logical AND conditions may be
implemented by software rather than by use of discrete logic gates,
but use of discrete logic gates is within the scope of the
disclosure as well.
[0088] As mentioned above, each of modules 50, 52 includes lock-out
switch 80 and lock-out button 81 which are used to lock out various
functions of the modules 50, 52 and to unlock the functions. FIG.
15 is a diagram which illustrates the logic of the lock out
function of system 10. When switch 80 is in its position enabling
various functions of system 10, an output of an OR gate 178 is
turned on (i.e., a high logic state) and is coupled to the input of
a set of AND gates 180, each of which is associated with a
respective function as indicated generically at a "function A"
block 182 and at a "function Z" block 184 in FIG. 15. A "function
key A" switch 186 is coupled to the input of the AND gate 180
associated with function A and a "function key Z" switch 188 is
coupled to the input of the AND gate 180 associated with function
Z. Function A and function Z are intended to generically represent
the functions of system 10. The dotted lines appearing in FIG. 15
between switches 186, 188 and between the output of OR gate 178 and
the AND gate associated with function Z are intended to convey the
notion that additional functions may be controlled in the same
manner as the two that are illustrated.
[0089] When the output of OR gate 178 is on, which occurs when
system 10 is enabled, and button 186 or button 188 is pressed, the
associated AND gate has two high logic states at its input
resulting in its associated output being turned on (i.e., a high
logic state) to signal the operation of the associated function A
or function Z. If switch 80 is in its position disabling or locking
out the various functions of system 10, and assuming button 81 is
not pressed, then both inputs to OR gate 178 are at low logic
states and the output of OR gate 178 is off (i.e., a low logic
state) resulting in the output of the associated AND gates 180
being turned off, regardless of whether either of buttons 186, 188
is pressed.
[0090] If switch 80 is in its position locking out the various
functions of system 10 and switch 81 is pressed, then a twenty
second timer is activated, as indicated at block 190, resulting in
a high logic state being applied at one of the inputs of OR gate
178 for twenty seconds, thereby turning the output of OR gate 178
on, thereby enabling the various functions of system 10 for twenty
seconds. During this twenty period, switches 186, 188 may be
pressed to operate the associated function 182, 184. After the
expiration of the twenty second timer, the OR gate 178 once again
receives two low logic inputs which turns off the output of the OR
gate 178 thereby locking out the functions of system 10.
[0091] Switches 186, 188 are coupled to the inputs of an OR gate
192 as shown in FIG. 15. The output of OR gate 192 is coupled to a
lock light 194. Lock light 194 is turned on by OR gate 192 when
switch 80 is in its position locking out the functions of system 10
and lock light 194 flashes if either of switches 186, 188 is
pressed when system 10 is locked out. Although, logical AND gates
180 and logical OR gates 178, 192 are used in FIG. 15 to explain
the operation of the lock out function of system 10, it should be
appreciated that the logical AND and logical OR conditions may be
implemented by software rather than by use of discrete logic gates,
but use of discrete logic gates is within the scope of the
disclosure as well.
[0092] Although certain illustrative embodiments have been
described in detail above, variations and modifications exist
within the scope and spirit of this disclosure as described and as
defined in the following claims.
* * * * *