Irrigation syringe

An irrigation syringe which is particularly adapted for injecting water into a human body cavity, such as for the cleansing of an ear, includes a pressure regulator unit which is connected to, and supported by, a faucet, and a handpiece including a manually operable valve. The regulator unit includes a supply chamber having an inlet which is connected to a pressure water supply such as a faucet, an outlet which supplies pressure regulated water to the handpiece, and a pressure relief outlet having a check valve which opens to allow water to drain, such as into a sink, when the water pressure inside the regulator unit exceeds a predetermined value. A flow limiting orifice at the inlet to the supply chamber helps smooth out pressure fluctuations from the water supply and provides a steady flow from the supply chamber outlet. Temperature and pressure readouts are provided on both the pressure regulator unit and the handpiece.

BACKGROUND OF THE INVENTION 
This invention relates to a device for injecting water into a human body 
cavity, such as an ear, to effect cleaning thereof, and more specifically 
the invention relates to a syringe device which can inject water into a 
human body cavity continuously as desired. 
Those medical professionals who routinely clean patients' ears generally 
prefer to use irrigation syringe-type devices either alone or possibly in 
conjunction with curette-type devices. One of the most commonly used 
category of irrigation syringe-type devices is simple bulb-type devices, 
which are generally comprised of a flexible bulb having a single opening 
to which is fitted a nozzle through which water is ingested and 
discharged. Bulb-type syringes have several disadvantages and are often 
difficult to use as desired. Because the bulb can only contain a limited, 
relatively small quantity of water, the device cannot be used continuously 
for any desired amount of time, and it is often necessary to repeatedly 
refill the bulb to clean a patient's ear. Another disadvantage with 
bulb-type syringes is that the pressure of the water exiting the nozzle 
cannot be easily adjusted and monitored, which in turn can result in 
discomfort, pain, and possibly injury to the patient if the water is 
discharged from the nozzle at a pressure which is too high. Water exiting 
the nozzle opening of a bulb-type syringe at a pressure only slightly in 
excess of the desired pressure can impinge upon the tympanic membrane at a 
velocity which can cause considerable pain and even serious injury 
thereto. Even those bulb-type syringes having flow limiting devices 
installed within the nozzle or at the juncture between the nozzle and the 
bulb can eject water at a velocity, which can cause pain and injury upon 
impact with the tympanic membrane, if the bulb is squeezed with excessive 
force. Because the bulb must be squeezed by generally applying pressure 
thereto with the pall and fingers every time the syringe is filled or 
emptied, repeated use of the device can be fatiguing, aggravating, and 
even painful. 
Another known irrigation syringe includes a pump, connected to a fluid 
reservoir, and driven by an electric motor. Such devices are capable of 
pulsatingly or continuously ejecting water from a nozzle opening for a 
sustained period of time, but do not generally include temperature and 
pressure indicators for adjusting and monitoring the temperature and 
pressure of the water issuing from the nozzle. The use of an electric 
motor also has a number of inherent disadvantages, including increased 
expense in manufacturing the device and the noise of the motor, which can 
be annoying and stressful both for the operator and the person whose ear 
is being cleaned. Additionally, the water in the reservoir must be 
frequently replaced as it is used. 
Fountain-type syringes which are adapted to be connected with a pressure 
water supply such as at a faucet are not generally used for cleaning ears, 
because the known devices of this type have not delivered the water to the 
nozzle opening at the desired pressure and flow rate. More specifically, 
while some of the fountain-type syringes have included pressure relief 
valves for limiting the pressure of the water delivered to the nozzle 
opening, pressure relief valves alone have not adequately provided smooth 
delivery of water at a relatively constant pressure to the nozzle opening, 
but have, instead, achieved only a modest, if any, dampening effect of 
water supply pressure fluctuations, resulting in a pulsating-type flow 
from the nozzle. Often the rapid opening and closing of the relief valve 
can itself create a pulsating flow from the nozzle opening. Such 
pulsations can be annoying to the operator and patient, and can even cause 
pain or injury to the tympanic membrane, which is sensitive to rapid 
pressure fluctuations. Additionally, known fountain-type syringes do not 
include pressure and temperature indicators, which allow adjustment and 
monitoring of the temperature and pressure of water being delivered to the 
nozzle opening. The prevailing opinion among physicians is that the ideal 
temperature for effective ear cleaning is from about 98.degree. F. to 
about 102.degree. F., because a lower temperature is not as effective for 
facilitating cleaning and that a higher temperature can cause a patient to 
experience dizziness and nausea. 
Accordingly, a relatively inexpensive, easy to use irrigation syringe 
capable of continuously discharging water from a nozzle opening for any 
desired period of time, and capable of delivering water to the nozzle 
opening at a relatively constant pressure during such period of time, 
would be highly desirable. Additionally, it would be desirable if such 
syringe included pressure and temperature indicators, which could be used 
for adjusting and monitoring the temperature and pressure of water 
delivered to the nozzle opening. Further, such device should preferably be 
free of pumps and electric motors to reduce the annoying and stressful 
noises associated with the operation of pumps and motors. 
SUMMARY OF THE INVENTION 
The invention provides an irrigation syringe including a pressure regulator 
unit which can be connected directly to, and supported by, a faucet, and a 
handpiece which can be gasped between the fingers and palm, and easily 
manipulated and maneuvered as needed to clean a person's ear. The syringe 
can discharge water from a nozzle opening at a desirable temperature, 
pressure, and suitable flow rate continuously for any required amount of 
time. 
In accordance with a first aspect of the invention, the pressure regulator 
unit includes a supply chamber having a liquid inlet for connecting the 
supply chamber to a pressurized water supply such as a faucet, and a 
liquid outlet, which is in fluid communication with an inlet of the 
handpiece. A flow limiting orifice at the inlet to the supply chamber 
restricts flow into the supply chamber and generally reduces the pressure 
of the water supplied from the faucet to provide a relatively smooth and 
constant flow into the supply chamber, e.g., the orifice tends to smooth 
out pressure fluctuations from the water supply and provides a more steady 
flow from the supply chamber outlet. The supply chamber also includes a 
pressure relief outlet having a check valve, which opens to relieve 
pressure in the supply chamber when a predetermined pressure is exceeded. 
In accordance with another aspect of the invention, the pressure regulator 
includes a liquid inlet and outlet, a pressure relief outlet, and at least 
one temperature indicator, which indicates the temperature of water within 
the syringe. A temperature indicator can be included on the regulator unit 
to provide feedback as the operator adjusts the valve(s) on the faucet to 
set the temperature. A temperature indicator can also be placed on the 
handpiece so that the operator can easily check and monitor the 
temperature by simply glancing over at the handpiece. 
The handpiece is preferably provided with a manually operable valve, which 
can be opened by merely exerting pressure, such as with a finger or thumb, 
on a button on the handpiece. Desirably, the valve can be comprised of a 
spring-loaded clamp, which normally pinches a flexible tube in the 
handpiece closed to cut off flow, and which allows flow from the nozzle 
opening when the button on the handpiece is held down. 
The regulator unit desirably includes a reservoir chamber, which is in 
fluid communication with the supply chamber through a flow-restrictive 
fluid connection such as a pipe or opening connecting the outlet of the 
supply chamber with the inlet of the reservoir chamber. Water flows from 
an outlet on the reservoir chamber through a tube to the handpiece. The 
flow limiting inlet orifice and pressure relief valve of the supply 
chamber in combination with the flow-restrictive fluid connection between 
the supply chamber and the reservoir chamber provide an air cushion at the 
upper portion of the reservoir chamber which achieves additional dampening 
effect to smooth out pressure fluctuations and pulsations caused by 
variations in the supply water pressure, rapid periodic discharge of water 
from the pressure relief outlet in the supply chamber, or both. 
Desirably the regulator unit has a pressure indicator, which the operator 
can use to verify that the syringe is working properly. The handpiece can 
also be provided with a pressure indicator, which the operator can 
conveniently monitor while cleaning a person's ear by merely glancing over 
at the handpiece. 
The nozzle on the handpiece is preferably adapted to reversibly receive a 
disposable, sanitary sheath which promotes proper hygiene. In accordance 
with a particularly desirable feature of the invention, the handpiece 
includes a lock which prevents the valve on the handpiece from being 
pressed, and thereby prevents flow from the nozzle opening, unless a 
specially adapted sheath is attached to the nozzle. The sheath includes 
circumferentially spaced lands which provide a gap or vent between the 
sheath and an ear opening so that excessive hydrostatic pressure does not 
occur within the ear canal. 
These and other features, objects, and benefits of the invention will be 
recognized by those who practice the invention and by those skilled in the 
art, from the specification, the claims, and the drawing figures.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
In FIG. 1 there is shown a syringe 10 incorporating the present invention 
which is suitable for cleaning a patient's ear. The syringe 10 includes a 
pressure regulator unit 12 and a handpiece 14. The pressure regulator unit 
includes an inlet opening with a quick disconnect coupling 16 connected to 
a faucet 18. Water is discharged from a pressure relief outlet 20 to 
maintain the water pressure inside the regulator unit 12 at a prescribed 
level. Regulated water issues from a supply outlet 21 on the regulator 
unit 12 and flows through a hose or tube 22 to handpiece 14. A manually 
operable valve having a pushbutton 24 is provided to control the flow of 
water from handpiece 14 into an ear which is to be cleaned. The handpiece 
14 is adapted to receive a single use, disposable sanitary sheath 26, 
which snaps onto the injection nozzle end thereof and is retained thereon 
by a frictional interference fit. A temperature indicator 28 on the 
regulator unit 12 is provided to monitor the temperature of water issuing 
from the supply outlet 21 of the regulator unit 12 and flowing to the 
handpiece. The temperature indicator 28 on the regulator unit 12 is 
observed during adjustment of the faucet valve(s) to help ensure that 
water flowing from the injection nozzle of the handpiece 14 is at a safe, 
desirable temperature, generally in a range from about 98.degree. F. 
(37.degree. C.) to about 102.degree. F. Regulator unit 12 is also provided 
with a pressure indicator 30, which can be used during adjustment of the 
faucet valve(s) to verify that the valve(s) is (are) sufficiently open and 
that the pressure regulator unit 12 is operating properly. After the 
faucet valve(s) has (have) been adjusted to deliver water to the handpiece 
at the desirable temperature and pressure, a medical professional or other 
operator of the ear syringe 10 grasps the generally cylindrical-shaped 
handpiece 14 and opens a valve in the handpiece by pressing on button 24 
to allow water to flow out from the injection nozzle end of the handpiece 
for cleaning a person's ear. 
A pressure regulator unit 12 which employs the principles of the invention 
is shown in FIG. 2. The regulator unit 12 includes a supply chamber 32 
generally defined by a vertically arranged cylindrical tube 34 having at 
its top end a bulkhead 36 with an opening receiving a flow limiting 
orifice 38. The bottom end of the cylindrical tube 34 is provided with a 
check valve 40 fitted within a connector 42. Orifice 38 restricts flow 
from the faucet into the supply chamber 32 to prevent overloading of check 
valve 40, to minimize the effects of supply line water pressure variations 
at the faucet, and to provide a relatively steady flow of water to the 
handpiece 14 when the valve therein is open. The cross-sectional flow area 
of the orifice 38 should be less than half, preferably from about two to 
about ten percent, and more preferably from about five to about ten 
percent, of the cross-sectional flow area of the check valve when it is 
fully open. A suitable cross-sectional flow area for the orifice is from 
about 0.002 to about 0.010 square inches. The flow limiter orifice 38 
generally reduces the flow of water into, and limits the flow of water 
through, the syringe and out from the nozzle opening to a maximum of about 
one liter every four to five minutes, depending upon the supply pressure 
of the water. A suitable diameter for orifice 38 is from about 0.025 to 
about 0.150 inches, and more preferably from about 0.05 to about 0.10 
inches. 
Check valve 40 is a poppet-type valve which remains closed below a 
preselected pressure differential and opens above the preselected pressure 
differential, whereby the check valve 40 acts as a pressure regulator. 
Suitable zero leakage, positive sealing, low inertia poppet design 
cartridge check valves are commercially available, e.g., model number 110 
from Smart Products, Inc., 2365 Paragon Drive, Unit H, San Jose, Calif. 
95131. Such valves are provided with a spring 44 which urges plunger 46 to 
seat against an O-ring 48, unless a predetermined pressure differential is 
exceeded which causes the spring to compress and the plunger to move 
downwardly and become unseated from the O-ring to allow water to flow 
outwardly from supply chamber 32. Spring 44 can be selected to allow the 
valve 40 to open at generally any desired pressure in the range from about 
0.2 to about 15 psi. However, to provide the desired cleansing action 
without risking pain or injury to the person whose ear is being cleaned, 
the check valve is preferably selected or designed to have an opening or 
cracking pressure of from about 1.0 to about 3.5 psi. 
The illustrated connector 42 is a generally cup-shaped fitting having an 
upstanding cylindrical section 50, which overlaps the end of cylindrical 
tube 34, an internal circumferential shoulder 52 against which the bottom 
edge of cylindrical tube 34 generally abuts, and an axial bore or opening 
54 in which check valve 40 is fitted. The connector 42 is sealingly 
secured to the lower end of tube 34 with a suitable cement or adhesive. 
The upper end of the tube 34 includes a female quick disconnect coupling 16 
threadably received in an adaptor 56, which is sealingly secured to the 
top end of tube 34 with a suitable cement or adhesive. Adaptor 56 has a 
lower cylinder portion 58 which overlaps the top end of tube 34, and an 
inner rim 60 which abuts the top edge of tube 34. A metal or plastic 
screen 62 is supported along its circumferential edges on an internal 
shoulder 64 of adaptor 56 and is captured between the shoulder 64 and the 
lower edges of female quick disconnect coupling 16. Screen 62 catches 
sediment and other solid materials to prevent such materials from plugging 
orifice 38 or entering the ear. The female quick disconnect coupling 16 
snaps onto a male quick disconnect coupling 64, which is threadably 
connectable to a faucet 18. Quick disconnect couplings, also known as snap 
fittings, are commercial available such as from Chicago Specialty, 377 
Woodland Avenue, Elyria, Ohio 44036. 
A lateral discharge outlet 66 is provided near the bottom end of tube 34 to 
supply pressure regulated water to handpiece 14. While regulated water can 
be supplied directly from discharge outlet 66 to handpiece 14 via tubing, 
the outlet 66 is preferably in fluid communication, via a connecting pipe 
67, with a reservoir chamber 68, which is generally defined by a second 
cylindrical tube 70. Tube 70 has a bottom supply outlet 72 through which 
pressure regulated water is supplied to handpiece 14 via tube 22, and a 
pressure indicator 30, which is sealingly secured to the top of tube 70. 
Pipe 67 has a cross-sectional flow area, which is preferably less than the 
cross-sectional flow area of open check valve 40. The flow limiting inlet 
orifice 38 and pressure relief check valve 40 of supply chamber 32 and 
flow restrictive connecting pipe 67 serve to provide an air cushion which 
is trapped at the upper portion of the reservoir chamber and acts as a 
buffer to pressure fluctuations in the water supplied by faucet 18 and 
pressure fluctuations caused by discharge of water through check valve 40, 
thereby providing more uniform pressure to the handpiece 14. Outlet 72 is 
comprised of a fitting having a cylindrical portion 76 secured, as with a 
suitable cement or adhesive, within a circular bore or opening 77 of a 
cap-type member 78, and an outward downwardly projecting barbed end 80 
which is adapted to be received within, and frictionally engage the inner 
walls at the end of a flexible tube 22. Cap-type member 78 has an 
upstanding cylindrical portion which overlaps walls at the bottom of 
cylindrical tube 70; and is secured thereto such as with a suitable cement 
or adhesive. 
Pressure indicator 30 is relatively simple, inexpensive, and can provide 
either a qualitative or, if desired, a quantitative indication of the 
pressure inside reservoir chamber 68. Pressure indicator 30 is comprised 
of a hollow, cylindrical piston 82 which has an open end 83 extending 
upwardly and is movable within a cylindrical volume 84 separated from the 
reservoir chamber 68 by a rolling diaphragm 86. Diaphragm 86 is an 
elastic, fluid-impermeable, balloon-like rubber or flexible synthetic 
component, the edges of which are continuously sealingly retained at the 
lower edges of the internal walls of the cylindrical volume 84. A 
compression spring 88 urges piston 82 downward toward reservoir chamber 68 
against stop shoulders 90 of a connector 92 which sealingly connects 
cylindrical tube 70 with internally tapered cylindrical tube 94. The top 
end of compression spring 88 engages the underside of a cap 95, which is 
secured to the top end of tube 94 such as with a suitable cement or 
adhesive, while the bottom end of spring 88 extends through upper, open 
end 83 of piston 82 and engages a generally upwardly facing surface of the 
piston. Sealing engagement between connector 92 and tubes 70 and 94 is 
maintained with compressible O-rings 96 and 97 located generally within 
circumferential grooves 98 and 99 of connector 92. 
As illustrated in FIG. 2, the edges at the opening of the balloon-like 
diaphragm 86 are continuously sealingly secured at the internally tapered 
section 100 of tube 94 by wedging the edges of diaphragm 86 and an 
overlying compressible O-ring 102 between a circumferential groove 104 at 
the top outer edge of connector 92 and the tapered section 100. The open 
edges of diaphragm 86 are preferably rolled up to form compressible 
O-ring-like portion 102. Attached to the piston 82 is a upstanding rod 106 
receiving spring 88 telescoped therearound and having calibration marks 
108 at its top end which indicate the pressure within the reservoir 
chamber 68. The rod 106 passes generally through the helical axis of 
compression spring 88 and helps properly position the spring 88 so that 
the helical axis thereof is generally parallel with the longitudinal axis 
of the piston and cylindrical volume 84. The top end of the rod 106, which 
bears calibration marks 108, passes through an opening 110 in the top of 
cap 95. Rod 106 extends further upwardly through opening 110 as the 
pressure differential between the reservoir chamber 68 and the volume 84 
above the diaphragm 86 increases. A clear, generally dome-shaped lens 112 
positioned over opening 110 can be provided with a sight line which can be 
visually aligned with one of the calibration marks 108 on the rod 106 to 
provide a pressure reading. The calibration marks can be qualitative 
(e.g., low, medium, and high) as shown in FIG. 2 or quantitative (e.g., in 
units of pressure such as psi) if desired. The cap 95 includes a vent 114, 
which provides fluid communication between the volume 84 and the ambient 
atmosphere to ensure that the reading provided by pressure indicator 30 is 
gauge pressure, i.e. pressure above ambient atmospheric pressure. 
Reference numeral 28 designates a temperature indicator attached to the 
exterior surface of the pressure regulator unit 12, which is used to 
measure the temperature of water passing therethrough and to handpiece 14. 
Various temperature indicating devices can be used, including 
thermometers, thermocouples, or the like. Preferably, temperature 
indicator 28 is of the type comprising a thin strip encapsulating liquid 
crystals which change color when the temperature changes. Such temperature 
indicators are relatively inexpensive and commercially available. A 
preferred temperature indicator, available from Cole-Parmer Instrument 
Company, Niles, Ill. 60714, is designated "Cat. no. G-90306-08." 
Handpiece 14 (shown in FIGS. 3A and 3B) includes a generally tubular 
housing 118 adapted to be hand-held, and which includes a fluid inlet 120 
in fluid communication with outlet 72 of the pressure regulator unit 12, 
and a manually operable valve 122 for controlling the flow of water from a 
water injection nozzle 124. Preferably, handpiece 14 also includes a 
temperature indicator 126 (which is preferably similar or substantially 
identical to temperature indicator 28 on regulator unit 12) and a pressure 
indicator 128 to facilitate convenient monitoring of the temperature and 
pressure of water being discharged from the handpiece 14 without needing 
to divert attention to the regulator unit 12. For convenience in 
maintaining proper hygienic conditions, the handpiece 14 is preferably 
adapted to receive a disposable sanitary sheath 26 which easily snaps onto 
and off of the fluid injection nozzle end of the handpiece. Sheath 26 
includes a plurality of fin-like projections or lands 119 which are 
uniformly spaced circumferentially about the exterior surface of the 
sheath. The space between adjacent lands 119 serve as vents to allow water 
to escape from the ear when the nozzle is inserted into an ear, thereby 
providing a safety feature which prevents excessive hydrostatic pressures 
from building up in the aural canal. 
The fluid inlet 120 to handpiece 14 is a tube coupling which passes through 
and is secured in an opening or bore 130 through an endcap 132, which is 
attached at an inlet end of housing 118. The outwardly projecting end of 
tube coupling 120 is received within an end of a flexible tube 22 through 
which water flows from the regulator unit 12 into handpiece 14. In 
accordance with a preferred aspect of the invention, endcap 132, cylinder 
walls 134, and internal end wall 136 together define an information-water 
supply module 137 having a water tight fluid chamber 138. The module 137 
includes, in addition to inlet 120, an outlet tube 140 having a 
circumferential groove 141 in which is received an O-ring 142. Outlet tube 
140 is inserted into an opening through bulkhead 174 with O-ring 142 
providing a water tight seal between outlet 140 and tube connector 180. 
The module 137 is designed so that it can be easily withdrawn from the 
handpiece 14 and replaced with another similar module in the event that 
the pressure indicator 128 or temperature indicator 126 should become worn 
or damaged. More specifically, module 137 has a cylindrical or barrel 
shape which slides into a cylindrical recess of the handpiece which is 
generally defined by wall 118 and bulkhead 174. The module 137 is 
preferably snap-fit into the end of the handpiece 14, and includes 
appropriate detents or the like which can be engage by conforming recesses 
on the walls 118. 
Pressure indicator 128 is generally similar to pressure indicator 30 of the 
regulator unit 12. More specifically, pressure indicator 128 includes a 
cylindrical piston 145 which is open at one end 143 and is movable in a 
cylindrical volume 144 within a tube 160. Volume 144 is separated from 
pressurized water which enters an inlet opening 146 by a rolling diaphragm 
148, generally similar to diaphragm 86. Piston 145 is urged against a 
shoulder 150 of a stop member 152 by a compression spring 154, the ends of 
which bear against opposing surfaces of endcap 132 and piston 145. Stop 
member 152 has a circumferential groove 155 at one end for receiving a 
compressible O-ring 156. The edges at the opening of balloon-like 
diaphragm 148 are continuously sealingly secured by wedging the edges of 
diaphragm 148 and overlying O-ring 156 between groove 155 and a tapered 
section 158 of tube 160 which generally defines volume 144. Rod 162 having 
calibration marks 164 is attached to piston 145, and projects through the 
helical axis of spring 154 and through an opening or bore 166 in endcap 
132. The calibration marks 164 can be seen through a clear, generally 
dome-shaped lens 168 positioned over opening 166. A vent 170 in endcap 132 
provides communication between the volume 144 and the ambient atmosphere 
to provide a gauge pressure reading (i.e., pressure above ambient 
atmospheric pressure) of the pressure regulated fluid in the handpiece 14. 
Pressure indicator 128 can be supported within handpiece 14 by securing 
tube 160 to an interior surface of housing 118 and/or an interior surface 
of endcap 132. Any suitable means such as cement or adhesive can be used 
to secure tube 160 to housing 118 and endcap 132. 
A pinch-type valve 122 (FIGS. 3A, 4A and 4B) is disposed at a valve section 
173 of handpiece 14, which is generally delimited by a bulkhead 174 which 
is situated intermediate the ends of the handpiece, and a nozzle 124 which 
is positioned at the end of the handpiece opposite to inlet 120. When 
valve 122 is open, regulated water flows from the regulator unit 12 into 
handpiece 14 through tube 22, inlet tube coupling 120, fluid chamber 138, 
rigid tube connector 180 passing through and secured within a bore through 
bulkhead 174, flexible tube 176, rigid tube connector 182 secured at one 
end of an axial cylindrical bore 183 through nozzle 124, a reduced 
diameter section 184 of the bore 183, and through and outward from an open 
end of a rigid tubular nozzle tip 185. 
Valve 122 (FIG. 3A) includes upper beatings 186, 187 and a lower movable 
bearing 188 having a rounded upwardly projecting protuberance which 
normally forcibly pushes up against the lower surface of flexible tube 176 
causing it to pinch closed, as shown in FIG. 3(A). Bearing 186 is an 
integral part of stem 189 which passes between fixed bearings 186, 187 and 
extends outwardly through aperture 190 in the side of housing 118. The 
outward end of stem 189 is attached to the underside of a pushbutton 24. A 
spring 194 has ends which bear against the underside of button 24 and the 
recessed bottom of cup-shaped spring retainer 196 to urge button 24 
upwardly as shown in FIG. 3(A). Button 24 is pressed such as with a thumb 
or finger to lower bearing 188 downwardly to the position A (indicated by 
dotted lines). Due to the resiliency of tubing 179, this allows the 
flexible tube 176 to flex, expand, and return to a normal cylindrical 
shape B (indicated by dotted lines) which causes water to flow freely 
therethrough and from the nozzle end of the handpiece 14. 
Nozzle 124 includes a circumferential rib 198, which engages a 
circumferential groove 200 on the interior wall of a disposable generally 
cone-shaped safety sheath 26. Hence, sheath 26 can be snapped on and off 
of nozzle end 176. 
In accordance with a further preferred aspect of the invention, alternate 
handpiece 14' (FIGS. 4a and 4b) is provided with a spring-loaded valve 
lock 202 which prevents button 24 from being pressed downwardly to unpinch 
tube 176 and allow water to flow therethrough unless a specially adapted 
sheath 26' (FIGS. 4A and 4B) is secured to nozzle 124'. This feature will 
generally prevent use of handpiece 14' unless sheath 26' is secured 
thereto. Because sheath 26' will typically be removed and disposed of 
after a single use, valve lock 202 helps promote proper hygiene. Lock 202 
slides along the inner wall of housing 118 from a first position (FIG. 4B) 
wherein a recess 204 is aligned with bearing 188 to allow button 24 to be 
freely pressed and released as desired, to a second position (FIG. 4A) 
wherein a raised land portion 206 adjacent to the recess 204 acts as a 
stop which prevents bearing 188 from being moved downwardly to allow flow 
through tube 176 and out of handpiece 14'. Lock 202 is guided between the 
locked position (FIG. 4B) and the unlocked position (FIG. 4A) by shafts 
208 and 210 which are attached to opposite sides of lock 202 and 
maintained in substantially axial alignment by circular bore 212 through 
nozzle 124' and circular bore 214 through wall 216 which is fixed to the 
interior wall of housing 118. When sheath 26' is removed from nozzle 124' 
with button 24 released, a spring 218 urges lock 202 toward nozzle 124' 
until a stop ring 220 affixed to shaft 208 engages interior transverse 
wall 222 of nozzle 124', and raised portion 206 of lock 202 is disposed 
beneath bearing 188 to prevent downward movement thereof. Spring 218 is 
positioned on shaft 210 with its helical axis generally coincident with 
the longitudinal axis of shaft 210, and with the ends of spring 218 
engaging wall 216 and lock 202 to urge lock 202 to the left and away from 
wall 216 as shown in FIG. 4B. Sheath 26' includes a cylindrical stub 224 
projecting from the inner wall thereof. When sheath 26' is properly 
attached to nozzle 124', stub 224 slides into bore 212 and engages the end 
of shaft 208 and forces it, along with lock 202, to move toward the water 
inlet side of handpiece 14 against the force of spring 218 until recess 
204 is directly beneath bearing 188 so that it can be moved downwardly 
unimpeded by lock 202. To facilitate a snap-type attachment of sheath 26' 
to nozzle 124', nozzle 124' includes a circumferential rib 198 which 
engages a circumferential groove 200 on the interior wall of sheath 26'. 
In accordance with another embodiment of the invention, a regulator unit 
12' (FIGS. 5a and 5b) can be provided with supply chamber 32' and 
reservoir chamber 68' integrally formed together such from a polymeric 
thermoplastic using an injection molding process. Regulator unit 12', 
except for its shape and a plurality of check valves 40a, 40b, 40c (FIG. 
5B) and an associated check valve selector 226 (described hereinafter), is 
generally similar to regulator unit 12. Regulator unit 12' is generally 
box-shaped and includes a partition 228 which divides the interior thereof 
into supply chamber 32' and reservoir chamber 68', which are in fluid 
communication via an integrally formed flow restrictive, tubular 
passageway 67'. Regulator unit 12' also includes a quick disconnect 
coupling 16', a sediment screen (not shown), a flow limiting orifice (not 
shown), a temperature indicator 28', a pressure indicator 30', and an 
outlet 72', all of which are similar or substantially identical to the 
corresponding parts of regulator unit 12. 
Regulator unit 12' is also provided with a plurality of check valves 40a, 
40b, and 40c, each of which has a different opening or cracking pressure, 
and a pressure selector 226. The pressure selector has a pressure relief 
inlet 232 in fluid communication with supply chamber 32' and a flow 
selector valve 234. Check valves 40a, 40b, 40c each have an inlet 236a, 
236b, 236c, respectively, and an outlet 238a, 238b, 238c in fluid 
communication with the ambient atmosphere via pressure relief outlet 239. 
Valve 234 has a fluid passageway 240 which is movable to alternately 
provide fluid communication between pressure relief opening 232 and one of 
the inlets 236a, 236b, 236c. The cracking pressures for valves 40a, 40b, 
40c can be, for example, selected to provide a low water pressure to 
handpiece 14 such as about 1.0 to out 1.5 psi, a medium pressure such as 
from about 1.5 to about 2.5 psi, and a high pressure such a from about 2.5 
to about 3.5 psi. This allows the operator to choose a higher water 
discharge pressure to provide better cleaning action or to choose a lower 
water discharge pressure to reduce discomfort to an individual whose ear 
is being cleaned, should that individual exhibit sensitivity to the water 
being discharged into the ear. A flow limiting orifice at the inlet of 
reservoir chamber 32' in combination with valves 40a, 40b, 40c and flow 
restrictive tubular passageway 67' serve to provide an air cushion which 
is trapped at the upper portion of the reservoir chamber and acts as a 
buffer to pressure fluctuations, whereby water is delivered to the 
handpiece 14 at a more uniform pressure. 
Ear syringe 10 is prepared for use by connecting the inlet opening of the 
regulator unit (either 12 or 12') to a faucet 18, preferably using quick 
disconnect couplings 16 or 16' and 64, selecting the desired pressure if 
regulator unit 12' is being used, adjusting the faucet valve(s) while 
observing the temperature indicator 28 and pressure indicator 30 until 
adequate pressure and temperature is achieved. After the syringe 10 has 
been prepared for use, the operator attaches a new, sanitary sheath 26 or 
26' to the nozzle, merely grasps the handpiece 14 in one hand and, using a 
finger or thumb on that hand, depresses button 24 to cause water to issue 
from the nozzle end of the handpiece. The operator can easily monitor 
temperature and pressure of water issuing from handpiece 14 by 
occasionally glancing at the temperature indicator 126 and pressure 
indicator 128 on handpiece 14. 
A further alternative embodiment of the invention is shown in FIGS. 6A, 6B, 
6C, and 6D. The regulator unit 300 incudes a pair of concentric 
cylindrical tubes, including an outer rigid tube 302 which partially 
defines the housing for regulator unit 300, and an inner rigid tube 304 
(FIG. 6C) which, together with a base 306 and a top member 308, define a 
supply chamber 310 and a reservoir chamber 312. 
Regulator unit 300 includes a female quick disconnect coupling 314 adapted 
to be quickly connected to and disconnected from a male quick disconnect 
coupling 316 which is connected to a faucet 318. 
The unit 300 also includes a rotatable pressure selector valve 320 having a 
fluid passageway 322 which provides fluid communication between the supply 
chamber 310 and one of a plurality of inlet passageways 324, 326, 328 to 
check valves 330, 332, 334 respectively, which are poppet-type valves 
having different crack or opening pressures. The selector valve 320 is 
operatively connected to a knob 336 which is rotated to align passageway 
322 with one of the inlet passageways 324, 326, 328 depending on the 
desired pressure of the water which is to issue from a handpiece 14 (such 
as shown in FIGS. 1, 3A, 3B, 4A, 4B). Once a position for the selector 
knob 336 has been chosen, the associated check valve 330, 332, 334 will 
open if the pressure inside supply chamber 310 exceeds a predetermined 
level allowing water to drain from the unit through common drain opening 
338, which is in fluid communication with the outlet side of the check 
valves via outlet passageways 340, 342, 344. 
The base 306 includes concentric circular support walls 346, 348 which 
support and sealingly engage the interior walls of inner rigid tube 304, 
and the exterior walls of outer rigid tube 302, respectively. Tubes 302, 
304 are secured to walls 348, 346, respectively, by a frictional or 
interference-type fit. O-ring seal 350 provides a fluid tight seal between 
the interior side of wall 348 and the exterior side of rigid tube 302. 
O-ring seal 352 provides a fluid tight seal between the exterior side of 
wall 352 and the interior side of tube 304. 
The top member 308 is a cap-like member having central threaded inlet 
opening 354 for securely receiving female quick connect coupling 314, an 
inner circular wall 356, the outer side of which engages the interior side 
of inner rigid tube 304, and a depending skirt flange 358 the interior 
side of which engages the exterior side of tube 302. Tubes 302, 304 are 
secured to walls 358, 356, respectively, by a frictional or 
interference-type fit. O-ring seal 360 provides a fluid tight seal between 
the interior side of flange 358 and the exterior side of tube 302. O-ring 
seal 362 provides a fluid tight seal between the exterior side of wall 356 
and the interior side of tube 304. Positioned within the inlet opening 354 
is a sediment screen 364, for screening particulate matter which could 
cause injury if propelled toward the tympanic membrane, and a flow 
limiting orifice 366 which helps control flow through the unit 300 and to 
the handpiece 14 from outlet 368, and helps smooth out or dampen pressure 
and flow fluctuations from the faucet supply. A plurality of flow 
restrictive openings 370 in tube 304 allow water to flow into the annular 
reservoir chamber 312 between inner and outer tubes 304, 302. The openings 
370 are preferably sized so as to provide a flow restriction which helps 
further smooth out or dampen any flow or pressure fluctuations from the 
faucet. As with the previously described embodiments, flow limiting 
orifice 366, valves 330, 332, 334, and flow restrictive openings 370 
cooperate to provide an air cushion which is trapped at the upper portion 
of reservoir chamber 312 and which serves as a buffer to pressure 
fluctuation to provide a smoother flow of water to the handpiece. 
The top member 308, inner and outer tubes 302, 304 and base 306 are 
securely held together by a pair of side bars 372, each of which is 
secured, as with a fastener 374, at one end to the base 306 and at the 
other end to the top member 308. 
The regulator unit 300 includes a temperature indicator 376, and a pressure 
indicator 378, which are substantially identical to temperature indicators 
28, 28', and pressure indicators 128, 30', respectively, of the previous 
embodiments. 
Regulator unit 300 includes a vertical bore 379 in the base which provides 
fluid communication between the reservoir chamber 312 and the outlet 368. 
A valve 380 is also provided in the base with fluid passageway 382 
connecting bore 379 with one side of valve 380 and passageway 384 
connecting the other side of the valve 380 with the passageway 328 and 
drain opening 338. A knob 384 is operatively connected to valve 380 which 
can be opened to allow liquid to drain from the regulator unit 300 after 
use. 
To use regulator unit 300, inlet opening 354 is first connected to a water 
supply, such as by connecting female quick disconnect coupling 314 to a 
male quick disconnect coupling 316 threaded onto a faucet 318. The desired 
pressure selection is then made by turning knob 336 to the appropriate 
position. For example, valves 330, 332, and 334 could be selected so that 
the supply pressure of water delivered to the hand unit can be about 1/2, 
1, or 11/2 psig, as desired, depending on which valve is selected. Next, 
the valve 380 should be closed by appropriate rotation of knob 384. A 
handpiece (such as handpiece 14 shown in FIG. 3A) is then connected to the 
outlet 368 through a flexible tube. The valve(s) for faucet 318 is (are) 
then turned on and adjusted to achieve the desired temperature. After the 
desired temperature is achieved, the handpiece can then be used to clear a 
person's ear by pressing on button 24 to allow water to issue from nozzle 
tip 185. 
It will be understood by those who practice the invention and by those 
skilled in the art, that various modifications and improvements may be 
made to the invention without departing from the spirit of the disclosed 
concept. The scope of protection afforded is to be determined by the 
claims and by the breadth of interpretation allowed by law.