U.S. patent number 3,778,570 [Application Number 05/299,437] was granted by the patent office on 1973-12-11 for enuresis bed pad.
Invention is credited to Joseph G. Shuman.
United States Patent |
3,778,570 |
Shuman |
December 11, 1973 |
ENURESIS BED PAD
Abstract
An enuresis bed pad is constructed with a plurality of parellel
electrically conductive sensor strips which are bonded to but not
embedded in, nor flush with, one surface of an essentially
non-stretchable, water-proof, electrically insulative substrate.
The sensor strips are spaced on the substrate so that they are
normally electrically insulated. The complete structure is
relatively thin, flexible and crease resistant. When any two
adjacent sensor strips are bridged electrically by the electrolytes
in urine, an external circuit is closed and audible and/or visual
signals are activated. The sleeping person is awakened.
Inventors: |
Shuman; Joseph G. (Scotch
Plains, NJ) |
Family
ID: |
23154779 |
Appl.
No.: |
05/299,437 |
Filed: |
October 5, 1972 |
Current U.S.
Class: |
200/61.05;
324/446; 340/604 |
Current CPC
Class: |
A61F
5/48 (20130101) |
Current International
Class: |
A61F
5/48 (20060101); G01n 027/30 () |
Field of
Search: |
;200/5A,61.05,52R
;128/417 ;324/30 ;340/235 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Scott; J. R.
Claims
I claim:
1. A urine flow sensor pad comprising: a laminate of a relatively
thin and flexible, waterproof, electrically insulative crease
resistant and essentially non-stretchable substrate;
a plurality of thin current conductive sensor strips respectively
applied from continuous rolls thereof and bonded to one surface of
said substrate in spaced and parallel arrangement;
said strips forming contacts on said pad operable due to
electrolyte in urine thereon;
two polarity collector strip elements extending across opposite
ends of said strips and electrically connected in overlapping
contact therewith to different alternate and non-adjacent sensor
strips;
a layer of insulation interposed between and coextensive with the
overlapping ends of the remaining alternate and non-adjacent sensor
strips and the corresponding portion of the adjacent collector
strip; and
means for electrically connecting the two polarity collector strips
to an external electrical circuit.
2. A urine flow sensor pad according to claim 1, in which the ends
of alternate sensor strips are shaped to contact both sides of the
connecting collector strip.
3. A urine flow sensor pad according to claim 1, in which all of
said sensor strips are bonded to said substrate and are connected
to said polarity collector strips via punched polarity tabs.
Description
BACKGROUND OF THE INVENTION
Multiple sheet sensor pads for enuresis have been in use many
years. These consist of a top perforated metal foil sheet or
screen, a larger size insulating sheet and a bottom foil sheet.
These devices must be assembled and aligned each night. They are
subject to false signals (no urine flow) due to shifting or by
metal sliver penetration. Such false signals slow or even defeat
the training or conditioning process. In addition the sheets are
not durable because of contact each night with urine. They are not
readily sanitized and are crinkly and messy to handle after each
use.
When the two metal components are bridged electrically by the
electrolytes in urine, an external circuit is energized. The latter
is usually designed with a sensitive relay. With the flow of urine
an alarm is sounded which wakes the user. The circuits are such
that the current at the pad is so miniscule that it would not be
felt even if the pad were in contact with the bare buttocks of a
child or infant.
In Seiger U.S. Pat. No. 2,127,538, the aforementioned objections to
the multiple sheet pads are overcome by first fabricating comb-like
contact elements and embedding these in a soft rubber substrate, so
that they are flush with one surface of a soft rubber substrate,
but with one surface of the contact elements exposed. The complete
structure results in a unified single sheet sensor pad. The single
sheet pad is easy to use, is false-signal-proof, and generally
effects faster training.
The design of such a pad does not make it adaptable to continuous
manufacture and the prefabricated comb-like contacts are difficult
to handle, as the average pad is approximately 18 .times. 26
inches. Fabrication of these delicate comb-like contacts involves
substantial labor costs. Embedding by pressure and/or heat or even
by a casting and curing process, makes the per unit cost high. The
marketing of such devices is generally done on a rental basis only,
and at a very high cost.
In Seiger U.S. Pat. No. 2,644,050 greater ease of manufacturing is
discussed, through use of a plurality of comb-like contact elements
which are shorter and easier to handle. These are embedded, but
flush with one surface of the substrate. A collateral benefit is
discussed which states that such a pad has greater flexibility and
durability. In either types we are faced with an individual lay up
operation for each pad.
The object of my invention is to provide a single sheet urine flow
control pad with the aforementioned advantages and with a structure
that is readily adaptable to a continuous fabrication process, that
is to say, on a roll to roll basis. All that remains to complete
the pad, after automatically cutting to sheet size, is to provide
polarity collector strips and terminals which is readily
accomplished with little additional labor.
A further object is to provide a single sheet enuresis pad which is
low in cost. The pad manufactured according to my structure and
method achieves the same result and is used in the same manner as
other high cost pads. Thus, many people suffering from enuresis are
not economically barred from taking advantage of what is recognized
as the best type of pad (single sheet) to end the enuresis
problem.
Another object is to provide a low cost single sheet enuresis pad
which may be purchased outright and not rented. This relieves the
trainee and family of the psychological pressures to achieve
satisfactory results within a specific time limit. The pad of the
present invention and the ancillary signal unit are also available
for a second child with little or no extra costs.
SUMMARY OF THE INVENTION
The present invention relates to the fabrication of a structure
resulting in a single sheet urine flow sensor pad. Thin current
conducting sensor strips are bonded to one surface of a sheet-like,
essentially non-stretchable, relatively flexible and crease
resistant and electrically insulative substrate, but not embedded
nor flush with the surface thereof. The sensor strips are parallel
and insulated from each other by the supporting sheet.
The pad described in this invention is most economically fabricated
on a roll to roll sequence. After the sheet is fabricated with the
bonded sensor strips in place, it may be cut to any desired length
and two polarity collector elements are electrically connected to
alternate and non-adjacent sensor strips. One of the two polarity
collector strips is attached to the first, third, fifth, etc.
sensor strip at one end of the pad. The other sensor strips, that
is, the second, fourth, sixth, etc. are attached to a second
polarity collector strip which is electrically insulated from said
first collector strip. Attachment is accomplished in a manner so as
to provide electrical continuity.
Terminals or connecting wires are attached at one edge of the pad
for convenience in actual use. The one is directly connected to the
polarity collector strip at that end of the pad and the second is
connected to a sensor strip which in turn is attached to the
polarity collector strip at the other end. In effect, the latter
sensor strip functions as a part of a polarity collector strip. It
may be made somewhat thicker than the other sensor strips. Thus,
any two sensor strips are of opposite polarity and may be
electrically bridged by the electrolytes in urine.
The structure and fabricating technique overcome the problems of
handling, positioning, and embedding delicate comb-like electrodes
in a soft rubber substrate. This could entail almost complete hand
assembly.
BRIEF DESCRIPTION OF THE DRAWING
Referring to the drawings:
FIG. 1 is top plan view of urine flow sensor pad.
FIG. 2 is bottom view of FIG. 1.
FIG. 3 is an enlarged section of FIG. 1 taken on Lines 3--3.
FIG. 4 is a fragmentary view illustrating a punched polarity tab
and polarity collector strip ready for application.
FIG. 5 is a section on line 5--5 of FIG. 1.
FIGS. 6 & 7 are views taken on line 6--6 and 7--7,
respectively.
FIG. 8 is a fragmentary bottom view of FIG. 5.
FIG. 9 is a diagramatic illustration of the external electrical
signal circuit.
DETAILED DESCRIPTION OF DRAWINGS AND PREFERRED EMBODIMENTS
Referring to the drawings the complete single sheet enuresis pad is
shown in FIG. 1. The substrate 10 has bonded to its one surface the
several spaced electrically conductive sensor strips 11. The
polarity collector strips 13 and 13a are attached to alternate
sensor strips on the other side of the substrate 10 via the punched
polarity tabs 14. Leads 16 and 16a and insulated terminal connector
wires 17 are attached to selected sensor strips 11a and 11b, FIG. 1
as shown. It is understood that the wires 17 are stripped at their
ends for electrical attachment to leads. The leads and polarity
collector strips are protected and insulated by covering with
waterproof insulating tape 20. It will be noted that lead 16a is
connected and insulated from polarity collector strip 13. The
sensor strip to which it is connected 11a serves as part of the
polarity collector strip 13a. There is an advantage to the
indicated positioning of the leads arranging for two sensor strips
between both. Even if electrical bridging by urine occurs between
sensor strips 11a and 11b near leads, the current path and
electrical conductivity is about the same as at any other point on
the pad. The tape shown on the long sides of FIGS. 1 and 2 are not
functional but decorative.
When the circuit is closed by electrolyte bridging, connector wires
17 which are attached to wires 27 or FIG. 9 energize relay coil 23
which pulls in armature 25 to relay contact 22 when main switch 24
is closed. Battery 21 then causes buzzer 26 to emit its signal
which wakes the trainee. A 3-6V battery is generally used.
FIG. 3 shows in section the substrate 10 with the spaced sensor
strips 11 and waterproof bonding material 12. While these are
bonded to one surface of substrate but not embedded nor flush with
said substrate's surface, the combined total height of 11 and 12 or
18, is approximately 3 to 5 mils. This protrusion from the surface
is small and does not pose a discomfort problem to the user. Since
the pads are generally used under the top bed sheet, the protrusion
is just not felt and the user is quite comfortable.
There are many ways in which the polarity collector strips may be
attached to the sensor strips such as by, use of conductive
cements, ultrasonic welding, or use of thin plastic clips.
Attachment on the sensor strip side may also be achieved by tape
insulation of alternate ends of sensor strips or by sensor strip
end removal, cutting away alternate ends of alternate strips. The
polarity collector strips can then be mounted on the sensor strip
side.
In the preferred embodiment of my invention, one of the two
polarity collector strips 13 is attached by disposing the punched
polarity tabs 14 of FIG. 4 to the unlaminated side of the substrate
10. In FIGS. 4 and 5, the polarity tabs are bent in a manner so as
to dispose their conducting surfaces outward. A flexible conductive
metal such as plain aluminum foil is folded over all the polarity
tabs at each end of pad. In this manner there is no way in which
the polarity collector strips can contact those sensor strips at
the same end of pad, but without polarity tabs. This is
accomplished efficiently with a special jig. After attachment, the
polarity collector strips 13 are taped. In FIG. 8, the bottom view
of the polarity collector strip is attached to a polarity tab, 14.
It is understood that the polarity collector strip bridges across
all the sensor strips on one side but separated by the substrate.
The polarity collector strips are connected to alternate sensor
strips via the punched polarity tabs.
Another important advantage with this method is that after taping,
as previously described, the contact between the tabs and polarity
collector strips is of a spring loaded character which is
considered good electrical practice. This results from the
resiliency of the bent substrate material. In addition, with the
close confinement of the connection by tape, contact is always
maintained, even if either tab or collector strip moves up or
down.
In the preferred embodiment of my invention an excellent balance of
non-stretchability and flexibility is achieved when I use a
polyester film as a substrate. Particularly preferred are
polyesters of terephthalic acid such as CELANAR (Celanese
Plastics), MYLAR (DuPont) and MELINEX (ICI). It is not to be
construed that this invention is limited only to this type of
substrate.
A polyester film in the thickness range of 5-14 mils (with an
optimal thickness of approximately 10 mils), has a very high
tensile strength and tensile modulous. Such a film is subject to
minimal dimentional change when used as an enuresis bed pad. Yet,
the film is fairly flexible, comfortable in use and
crease-resistant. These properties are important in maintaining the
integrity of the sensor strips. Additional treatment of the latter
important factor will be covered under sensor strip
specifications.
Biaxially oriented polypropylene treated to promote adhesion,
polyimide and special types of polyamide (Nylon) films are also
useful for substrate selection. In all instances films with no
plasticizer or, if present, with non-migrating type, are
recommended so that no reaction will occur when in contact with
bonding adhesive.
Another important advantage in the use of tough,resilient, flexible
and crease-resistant films as substrates, is that they tend to
remain flat, that is, when flexed, they spring back to their
original flat configuration as the enuretic trainee shifts and
turns during sleep. In use the actual degree of convex or concave
distortion is minimal, owing to the properties of the preferred
types of films. Here again, this favors maintenance of sensor strip
integrity. Kinking and fracture of these sensor strips are
minimized.
In the preferred embodiment of my invention the sensor strips 11 of
FIG. 1 are 2 to 3 mils-thick aluminum foil of low temper and with 1
to 2 mils of pressure sensitive adhesive or flexible heat sealable
adhesive coated on one side of the foil. There are many, many
adhesives of the latter types which bond well to aluminum and the
substrate that can be supplied by several adhesive and/or adhesive
tape manufacturers. Therefore, precise specification of this
element is not needed here to teach the substance of the total
invention. The sensor strips are approximately one-half inch wide,
although this dimension is not critical. They are spaced about
one-fourth to five-eighths inch apart.
Although aluminum foils are specifically mentioned, it is
understood that the invention is not limited to the use of this
material. For example, very thin stainless steel foils, or steel
and copper foils now available tinned to inhibit corrosion, may be
used with appropriate adjustments.
The bonding or laminating of the sensor strips to the substrate is
accomplished by mounting and spacing rolls of the sensor strip
material on a common shaft and arranged so that they are let off
from this unwind position in a differential manner. One skilled in
the art of laminating is well familiar with this tension
compensating technique, so that further details are not
necessary.
Referring now to the integrity of the sensor strips, previously
mentioned (Page 8), if, for example, the substrate in use stretches
considerably in the direction transverse to the sensor strips, the
length of the substrate diminishes as in stretching a rubber sheet
in one direction. This causes the sensor strips to develop fairly
large kinks at many points because the metal strips are inelastic
and cannot follow the dimentional changes of the stretchy type of
substrate. These kinks ultimately lead to fracturing. If a few
(non-terminal) sensor strips fracture the pad can still function.
When many do, the pad becomes deficient or useless. Minute kink
development, over long use, with the non-stretchy substrates, is
acceptable, because they do not propagate and ultimately lead to
sensor strip fracture.
If the sensor strips are inordinately stretched in the same
direction in which they are bonded, their elastic limit is
generally exceeded and they fracture. In addition to this, constant
and sharp flexing of the sensor strips by the movements of the
sleeping user, tend to subject the sensor strips to flex-fatigue
and they are subject to fracture when used with stretchy
substrates. They do not fracture when the non-stretchable types
specified are used in the pad structure. The use of
non-stretchable, fairly flexible substrates, which do not bend
sharply in use, solve the sensor strip fracture problem in a
practical manner.
In the preferred embodiment of my invention the polarity collector
strips, 13, FIG. 1, are of 2 mil plain aluminum foil which is
electrically conductive on both its surfaces. The use of aluminum
polarity collector strips in contact with the aluminum of the
polarity tabs, 14, FIG. 4, eliminates galvanic corrosion.
* * * * *