Abstract:
A colonic irrigation apparatus for cleaning bodily orifices such as the large intestine, which converts pressurized water from a building&#39;s water supply into a gravity flow and which provides precise temperature control even at extremely low flow rates. Water temperature is regulated by alternating the flow from separate hot and cold water inlets around a preset temperature set point, and sending the water into a filter. The filter blends the water, evening the temperature, whereupon the water passes through a temperature safety valve and on to an elevated pressure-to-gravity converter. Pressure is regulated by the converter, which receives the pressurized water, drains most of it under the flow of gravity to the patient at a preset flow rate, and vents the excess pressure by diverting a variable flow of the incoming water down to a drain.

Description:
FIELD OF THE INVENTION 
     This invention relates generally to an apparatus for performing colon hydrotherapy, or colonic irrigation, and specifically to a colon hydrotherapy apparatus having precise water temperature control. 
     BACKGROUND OF THE INVENTION 
     Colonic irrigation is a process of cleansing the tissues of the lower intestine with water for purposes of removing impacted fecal material and other potentially toxic waste. Colonics are performed both as a preventive measure to sustain healthy digestion, peristalsis, and bowel tissue, and as a treatment for specific diseases such as colitis. Many of the problems addressed by colon hydrotherapy are associated with the typical “western” diet which is low in fiber, centered on meat, dairy, and processed foods, and which is poorly suited for the human digestive tract. 
     Medical devices have been employed in colonic irrigation for many years. For example, in 1935, U.S. Pat. No. 2,024,967 was issued for an apparatus to rehabilitate peristalsis of the colon. Over the years, colonic lavaging devices have evolved to include certain controls such as water temperature and pressure regulating devices, which ease administration of the colonic while insuring the comfort and safety of the patient. In the typical hydrotherapy procedure, the patient lies on her back or side, and a tube is inserted into the rectum. Fresh water flows into the bowel, loosening waste material from the walls of the colon and allowing the loosened waste material to flow out of the colon. 
     In the past two decades, colonic machines have reached a relatively high degree of refinement, as has the growing practice of colon hydrotherapy. More recent examples of prior art mechanisms and systems employed in colonic lavage may be seen in U.S. Pat. Nos. 4,190,059, 4,626,239, 4,682,979, and 4,842,580. While most devices are intended for professional use by a licensed colon hydrotherapist, devices have also been designed for home use, such as U.S. Pat. No. 4,645,497. Throughout the continuing evolution in hydrotherapy devices, two variables have remained key in delivering quality colonic treatment: water temperature and water pressure. Precise temperature control is important, not only for safety and comfort of the patient, but also because temperature can affect the peristaltic action of the bowel. Selecting the proper temperature, or alternating the temperature between warm and cool during the colonic, heightens the benefits of the procedure. Precise pressure control is important as excessive water pressure can cause pain and even injury. 
     Early colonic machines used hot and cold water from a building&#39;s plumbing system and simply used gravity to provide safe water pressure. The hot and cold water are passed through a mixing valve to achieve the desired temperature. Water is then delivered into an elevated tank or reservoir. From there, the water flows down naturally into a speculum and to the patient. 
     By the late 1970s, several problems had become apparent with this type of system. First, the reservoir, which may hold five or more gallons, makes the machine bulky and a more or less permanent installation. Second, precise temperature control is extremely difficult. If the reservoir is inadvertently filled with water that is too hot or too cold, the patient must wait either for the water to adjust on its own, or for the tank to be drained and refilled. Third, once the temperature in the reservoir is established, it cannot be easily varied during the course of the colonic. Fourth, the only way the pressure can be varied is by raising or lowering either the patient or the entire reservoir. 
     Later colonic machines, starting with U.S. Pat. No. 4,190,059, have addressed these problems by employing regulating valves to control water pressure. In such machines, hot and cold water still come from a building&#39;s plumbing system and are mixed through a thermostatically controlled mixing valve to achieve the desired temperature. However, one or more pressure regulating valves then keep the water pressure controlled within a certain range. While this method represents a major improvement over the earlier reservoir method, it too has several shortcomings. First, while temperature is certainly more controllable, water temperature through the mixing valve may still vary by a factor of several degrees. Second, the temperature of the water delivered during the procedure is vulnerable to pressure variances within the building&#39;s hot and cold water supply lines. Third, after nearly two decades of using such devices, a number of colon hydrotherapists and patients have come to perceive the earlier, gravity-pressure system as an inherently safer method. Their preference for this more natural type of pressure control is evidenced in part by continued sales and usage of the older reservoir systems, despite their numerous limitations. The present invention, therefore, is directed at alleviating all of these problems and limitations that are associated with both types of colonic irrigation machines of the prior art. 
     SUMMARY OF THE INVENTION 
     Objectives of the present invention include providing a colonic irrigation apparatus and method that provides for precise control of the temperature of the water to be delivered to the patient; that offers the benefits and safety of gravity pressurization without the disadvantages associated with machines that rely on bulky reservoirs or tanks; that is easy to set up, use, and adjust; that is highly compact and portable; that is versatile in that it may be used by professional colon hydrotherapists or by home users; and/or that can be used as a subcomponent of, or an attachment to, an existing colonic machine or as a complete system requiring only a colonic table or board. Related objectives include providing a hydrotherapy apparatus and method that provides a method of converting pressurized water from a building&#39;s plumbing system into a gravity pressurized flow, easily and conveniently, and provides a new method of controlling a temperature of water mixed from separate hot and cold water inflows, which is extremely precise, within 1° F., even at flow rates as low as 0.1 gallons per minute. 
     Further objects and advantages of the present invention will become apparent from a consideration of the drawings and ensuing description. 
     An apparatus for colonic irrigation is disclosed which features a new method of precisely regulating water temperature that far surpasses the technology used in any of the prior art and allows for gravity-pressurization, without the aforementioned limitations and bulk of a reservoir system. In one embodiment, the hydrotherapy apparatus includes: 
     determining means for determining a predetermined temperature for the lavaging liquid (e.g., a central processor, a user actuated control, etc.); 
     a temperature sensor (e.g., a thermister, a thermocouple, an RTD,etc.; 
     comparing means for comparing a first temperature of a first portion of a liquid with the predetermined temperature (e.g., a central processor, a comparator circuit, etc.), the comparing means being in communication with the determining means and the temperature sensor; 
     control means for generating a control signal (e.g., a central processor, a suitable electrical circuit, etc.) to contact second and/or third portions of the liquid with the first portion; 
     mixing means for mixing the first portion of the liquid with at least one of the second and third portions of the liquid to form an orifice irrigation liquid (e.g., a water filter, a baffled in line mixer, an impeller, etc.); and 
     introducing means for introducing the orifice irrigation liquid into the bodily orifice (e.g., a speculum). When the first temperature is less than the predetermined temperature (e.g., the first portion is cold water), a second portion of the liquid having a second temperature more than the predetermined temperature (e.g., the second portion is hot water) is contacted with the temperature sensor. When the first temperature is more than the predetermined temperature (e.g., the first portion is cold water), a third portion of the liquid having a third temperature less than the predetermined temperature (e.g., the third portion is cold water) is contacted with the temperature sensor. 
     The apparatus has a number of attractive features. It is capable of controlling the temperature of the liquid, prior to use in a patient, to within about 1° F., even at flow rates as low as about 0.1 gallons per minute. It achieves this goal by employing separate hot and cold water inflows and precisely mixing the inflows to attain the predetermined temperature. Mixing is performed by injecting alternating streams of hot and cold liquid into the mixing device. In this manner, the apparatus is largely unaffected by sudden changes in water pressure from a building&#39;s hot and cold water inlets. In addition, it is easy to set up, use, and adjust; it is highly compact and portable; it is versatile; and it can be used as a subcomponent of, or an attachment to, an existing colonic machine. 
     The apparatus can include a second temperature sensor for measuring a fourth temperature of the orifice irrigation liquid. In that event, the predetermined temperature is either the sum of (i) the first temperature and (ii) the difference between a selected temperature (e.g., a temperature selected by a user) and the fourth temperature when the fourth temperature is substantially constant during a selected time interval. When the fourth temperature varies substantially during the selected time interval, the predetermined temperature is preferably the selected temperature. 
     The control signal(s) generated by the control means causes the temperature sensor to be first contacted with one of the second and third portions of the liquid and thereafter with the other of the second and third portions of the liquid. For example in a typical application, pulses of hot water and pulses of cold water are sequentially and alternately contacted with the temperature sensor in response to the control signal(s). 
     In the event of malfunction of the temperature control system, the apparatus can include means for determining if the fourth temperature is within a selected temperature range. If the fourth temperature is outside of the selected temperature range (i.e., either above the range or below the range), at least a portion of the liquid is redirected away from the speculum and maintained free of contact with the bodily orifice for the safety and comfort of the patient. 
     In operation, the apparatus performs the following steps: 
     (a) contacting the first portion of the liquid with the temperature sensor; 
     (b) comparing the first temperature with the predetermined temperature; 
     (c) when the first temperature is less than the predetermined temperature, thereafter contacting the second portion of the liquid having a second temperature more than the predetermined temperature with the temperature sensor and, when the first temperature is more than the predetermined temperature, thereafter contacting the third portion of the liquid having a third temperature less than the predetermined temperature with the temperature sensor; 
     (d) thereafter mixing the first portion of the liquid with at least one of the second and third portions of the liquid to form an orifice irrigation liquid; and 
     (e) introducing at least a portion of the orifice irrigation liquid into a bodily orifice. 
     In yet another embodiment, the apparatus includes the following components: 
     a sensing module having (i) a first input for a cold liquid stream having a temperature less than the predetermined temperature, (ii) a second input for a hot liquid stream having a second temperature more than the predetermined temperature, (iii) a temperature sensor in communication with each of the first and second inputs, and (iv) an output; 
     a mixing device in communication with the output to form the orifice irrigation liquid; and 
     a controller for comparing a temperature signal from the temperature sensor with the predetermined temperature and generating a control signal either to open the first input and close the second input to contact the cold liquid stream with the mixing device or to close the first input and open the second input to contact the hot liquid stream with the mixing device. The first and second inputs can be in an opposing relationship with the temperature sensor (and/or output) being located between the opposing inputs. The system can include a shutdown valve located downstream of the mixing device and a second temperature sensor in the event that the temperature of the orifice irrigation liquid is outside of the selected temperature range (in which event the shutdown valve is closed). 
     The apparatus can include a pressure-to-gravity converter that is directly connected to a building&#39;s water supply. The converter includes a reservoir or casing that is open to the atmosphere at the top, an input from the building&#39;s water supply in the middle, an overflow located above the input, and an output to the speculum located below the input and the overflow. In one configuration, the reservoir is tubular with the output to the speculum and the open end of the tube being located along the longitudinal axis of the tube. The pressure of the orifice irrigation liquid can be easily adjusted by adjusting the height of the reservoir. During use, it is preferred that sufficient water flow into the reservoir that a continuous stream of water flows through the overflow to a drain. In this manner, a continuous and constant pressure is applied to the patient. 
     The above-noted converter is a gravity-pressurized system having all the benefits and advantages of a pressure valve regulated apparatus, without a bulky reservoir and other disadvantages formerly associated with gravity pressurized devices. The pressure-to-gravity converter allows for direct connection to a building&#39;s water supply while still providing gravity flow. It is well suited to both professional and home use. 
    
    
     BRIEF DESCRIPTION OF DRAWINGS 
     FIG. 1 is a front elevational view illustrating the two main components of the colonic irrigation apparatus which are the temperature and flow control device and the pressure-to-gravity converter. 
     FIG. 2 is a rear view of the temperature and flow control device shown in FIG. 1, detailing the rear panel. 
     FIG. 3 is a block diagram of the internal components of the temperature and flow control device shown in FIGS. 1 and 2. 
     FIG. 4 is a block diagram of the electronic elements of the temperature and flow control device shown in FIGS. 1 and 2. 
     FIG. 5 is a flow chart of software that controls temperature regulation and safety in the temperature and flow control device shown in FIGS. 1 and 2. 
     FIG. 6 is a detailed view of the pressure-to-gravity converter mechanism shown in FIG.  1 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1 shows the colonic irrigation apparatus of the present invention. The two main components of this apparatus are a temperature and flow control device indicated generally by the reference numeral  2 , and a pressure-to-gravity converter indicated generally by the reference numeral  40 . 
     Beginning with temperature and flow control device  2  (FIG.  1 ), the device is enclosed by a front panel  6 , left side panel  4  and right side panel  18 , bottom panel  24 , and a top panel  8 . Device  2  also has a demountable back panel  180  that is shown in FIG.  2 . The front panel  6  of device  2  (FIG. 1) features a standard flow gauge  28  with a needle valve  30 . Front panel  6  also features a temperature range decal  10 , and a digital temperature display  12 . Front panel  6  also features a temperature set point potentiometer  26 , an on/off switch  16 , a temperature safe indicator light  14 , and a water connector (female)  22  for outgoing water. 
     In FIG. 2, rear panel  180  of device  2  has a water connector  160  for incoming cold water, and a water connector  150  for incoming hot water. Connector  160  fastens to quick connect (male)  158 , which is attached to tube  156 . Connector  150  fastens to quick connect (male)  152 , which is attached to tube  154 . Tubes  154  and  156  are suitably adapted for connection to pressurized hot and cold water sources (not shown), such as conventional faucets or a building&#39;s water supply system. 
     The rear panel  180  also features houses a connector  166  through which water can exit device  2 . Connector  166  fastens to a quick connector (male)  164 , which is attached to a tube  162 . Tube  162  connects to a water filter  126 , which is housed in a filter compartment  178 . In the preferred embodiment, the water filter  126  is a KDF-55 filter, model R/O DeChlorinator (made by: Aqua Freshe Inc., P.O. Box 40, Prairie Hill, Tex. 76678). Water exiting the filter  126  passes through a tube  176  which is attached to a quick connect (male)  174 . Quick connect  174  fastens into a connector  172  allowing water to return into the device  2 . Finally, rear panel  180  houses a connector  170 , which fastens to a quick connect (male)  168 . Quick connect  168  is attached to a tube  182  through which water may exit device  2  and flow to a drain. 
     Leading in through back panel  180  to the interior components of temperature and flow control device  2  (FIG.  3 ), hot and cold water connectors  150  and  160  attach to a tube  110  and a tube  96  respectively. The tubes  110  and  96  connect to a hot water valve  112  and a cold water valve  98 , respectively. The valves  112  and  98  each contain an electrical coil,  114  and  100  respectively. The coils  114  and  100  are each connected by a pair of electrical wires  106  and  92  respectively, to a circuit board  86 . The valves  112  and  98  each connect to a tube  116  and a tube  102  respectively. The tubes  116  and  102  lead hot and cold water into opposite ends of a female cross  120 . A thermistor  118  (T 1 ) is inserted into a third end of cross  120 , such that it sits in the middle of the cross, exposed to hot and cold water coming from tubes  116  and  102  on either side. The thermistor  118  is connected by a suitable pair of electrical wires  104  to a circuit board  86 . The circuit board  86  is connected via a pair of electrical wires  82  to a 12 volt power supply  80 , which plugs into any standard AC outlet via a cord and plug  32 . The circuit board  86  is directly connected to the potentiometer  26 , the on-off switch  16 , the safety light  14 , and the digital display  12 . The circuit board  86  also houses a signal conditioner  90 , a set of power drivers  88 , and a microprocessor  84 . 
     Returning to the female cross  120 , the remaining end of the cross is connected to a tube  122 . The tube  122  carries water through a standard flow control valve  30  and flow meter  28 . Water leaves the meter  28  through a tube  124 . The tube  124  is attached to the connector  164 , which is fixed into the rear panel  180  (not shown in FIG.  3 ). The connector  164  attaches to the quick connect  166  which is attached to the tube  162 . The tube  162  connects to the water filter  126 . Water exiting the filter  126  passes through the tube  176  which is attached to the quick connect (male)  174 . The quick connect  174  fastens into the connector  172  which is fixed into the rear panel  180  of the device  2 . 
     The connector  172  is attached to a tube  128 , which directs the water to a female “T”  130 . The female “T”  130  houses a thermistor  132  (T 2 ), which is connected via a suitable pair of electrical wires  134  to the circuit board  86 . Water leaves the female “T”  130  via a tube  138 , and enters a fail safe valve  146 . The valve  146  contains an electrical coil  140 , which is connected via a pair of electrical wires  136  to the circuit board  86 . If the valve  146  is closed, water flows out of the rear panel  180  of the device  2  via a tube  142  and to a drain (not shown). If the valve  146  is open, water flows through a tube  148 , out of the front panel  6  of the device  2 , on its way to the pressure-to-gravity converter  40 . 
     The electronics of the temperature and the flow control device  2  are illustrated by FIG.  4 . Beginning at the right side of FIG. 4, temperature readings run from the potentiometer  26 , and from the thermistors  118  and  132 , to the circuit board  86  (shown in FIG.  3 ). The circuit board  86  houses and connects the signal conditioner  90 , the processor  84 , and the power drivers  88 . The signal conditioner  90  comprises a precision voltage regulator and a series of precision resistors that are arranged to convert the resistance of the thermistors  118  and  132  into voltage. Signals from the potentiometer  26 , the thermistor  118 , and the thermistor  132 , pass through the signal conditioner  90  where they are converted into binary code, and then relayed to the processor  84 . 
     The processor  84  is encoded with programming (described below and depicted in FIG. 5) which controls the digital outputs sent to the temperature display  12 , the temperature safe indicator light  14 , and the power drivers  88 . The power drivers  88  amplify outputs from the processor  84  and send corresponding signals to the electronic coils  114 ,  100 , and  140 . 
     Moving now to FIG. 5, software programming contained in the processor  84  (FIG. 4) is indicated and distinguished generally by the reference numerals  184 ,  186 , and  188 . The software  184  first sets an offset to zero. The software  184  then compares the voltage received from the thermistor  118  (FIG. 3) to the voltage received from the potentiometer  26 . If the voltage from the thermistor  118  is greater than or equal to voltage from the potentiometer  26 , the software  184  causes an appropriate signal to be sent to de-energize the electronic coil  114  (hot) and to energize the electronic coil  100  (cold). If the voltage from the thermistor  118  is less than the voltage from the potentiometer  26 , the software  184  causes an appropriate signal to be sent to energize the electronic coil  114  (hot) and de-energize the electronic coil  100  (cold). Thus, the software  184  generally serves to control the operation of the hot and cold water valves  112  and  98  (FIG.  3 ). The software  184  thus regulates the inflow of hot and cold water into the female cross  120  (FIG.  3 ). The software  186  generally controls the operation of the fail safe valve  140  (FIG.  3 ). The software  186  determines whether the voltage from the thermistor  132  is within a preset range corresponding to a temperature range of about 83° F. to about 103° F. If the voltage from the thermistor  132  is not within this preset range, the software  186  causes an appropriate signal to be sent to de-energize the failsafe coil  140  and the temperature safe indicator light  14 . If the voltage from the thermistor  132  is within this preset range, the software  186  causes an appropriate signal to be sent to energize the failsafe coil  140  and the temperature safe indicator light  14 . 
     The software  188  serves to correct for discrepancies between the voltage from the potentiometer  26  and from the thermistor  132  by way of the signal conditioner  90  (FIG.  3 ). If the reading from the thermistor  132  does not vary by 0.3° F. for at least five seconds, the software  188  assigns a value to an offset equal to the difference between the voltage from the potentiometer  26  and the voltage from the thermistor  132  by way of the signal conditioner  90 . The offset value in the software  188  is then added to the setpoint value in the software  184 . 
     Moving to the pressure-to-gravity converter mechanism  40  shown in FIG. 6, the male quick connector  20  connects the tube  34  to the water connector  22  which is fixed in the front panel  6  of the device  2  (shown in FIG.  1 ). Water flows through the tube  34 , which ends with a male quick connector  36 . The quick connector  36  inserts into a one-eighth inch diameter female quick connector  38 . The connector  38  fits tightly into a hole in the side of an outer casing  42 , which is the main component of the pressure-to-gravity converter  40 . The preferred embodiment of the casing  42  is a 12″ length of 1″ O.D.(nominal) schedule  40  PVC pipe. The casing  42  is open at the top, and a nylon cord  44  is affixed in a suitable manner to opposite sides of the opening such that the converter  40  may be hung from a hook (not shown) and suspended at a desired height. A one-half inch diameter barbed elbow connector  46  protrudes from the side of casing  42 . The elbow connector  46  is situated at a level between the top opening of the casing  42  and the female quick connector  38 , and on the opposite side from the connector  38 . The elbow connector  46  attaches to a tube  48 , which has an inner diameter at least two-eighths of an inch wider than the tube  34 . The opposite end of the tube  48  is open, and flows to a sink or drain (not shown), or may be permanently connected by suitable means to a drainpipe (not shown). 
     The bottom of the casing  42  is sealed with an end cap  50 . From the bottom of the end cap  50 , through a hole drilled in the cap, protrudes a female quick connector  52  which connects to a male quick connector  54 , which connects to a tube  56 , which connects to a standard check valve  58 . The check valve  58  connects to a tube  60 , which connects to a female quick connector  62 , which connects to a male quick connector  64 , which is attached to a tube  66 . A hose clamp  68  rests on the tube  66 , which is at least six feet in length. The tube  66  runs through a standard pinch valve  70 , and ends with a female quick connector  72 . The connector  72  attaches to a male quick connector  74 . The connector  74  attaches to a ⅜″ O.D. by ¼″ I.D tube  76 , which has a standard rectal tip (or speculum)  78  pushed into it. In the preferred embodiment, the speculum  78  is made by Ultimate Trends, PO Box 1427, Sandy, Utah 84091-1427. 
     It thus is seen that a colonic irrigation system is now provided which overcomes problems associated with those of the prior art. It should be understood, however, that the above-described embodiment merely illustrates principles of the invention in one preferred form. Many modifications, additions and deletions may, of course, be made thereto without departure from the spirit and scope of the invention as set forth in the following claims. 
     In normal operation of this invention, the hot and cold water tubes  154  and  156  are connected respectively by suitable means to a building&#39;s hot and cold water outlets. The pressure-to-gravity converter  40  is hung from a suitable hook approximately six feet above the floor. The tube  48  and the tube  182  are both connected (or directed) to a drain. The AC power cord  32  is plugged into a convenient AC outlet. Power is turned on via the on-off switch  16 , and the temperature setpoint potentiometer  26  is set to the desired temperature (thus determining the temperature setpoint). The temperature setting is displayed by the digital temperature display  12 . The hot and cold water outlets are turned on, and water flow rate is adjusted via the flow control needle valve  30  so that a moderate trickle of water is draining at all times from the pressure-to-gravity converter  40 , through the tube  48 , and into a drain pipe or sink, while water constantly flows out of the speculum  78 . 
     Hot and cold water enters through the tubes  110  and  96  and passes through the hot and cold valves  112  and  98 , and into the female cross  120 . The valves  112  and  98  have only two possible positions: fully opened or fully closed. At the cross  120 , the hot and cold water contacts the thermistor  118  (T 1 ) from opposite sides. The thermistor  118  sends water temperature readings in the form of voltage to the signal conditioner  90  via the circuit board  86 . The voltage from the thermistor  118  enters the signal conditioner  90  where it is converted into binary code, and then passed on via the circuit board  86  to the processor  84 . Based on the software  184 , if the temperature is too high relative to the desired temperature setpoint, the cold water valve  98  is opened and the hot water valve  112  is closed, such that only cold water enters the system and flows to the thermistor  118 . The thermistor  118  cools and passes below the setpoint, whereupon, based on the software  184 , the cold water valve  98  is closed and the hot water valve  112  is opened, such that only hot water enters the system and flows over the thermistor  118 . This process continues back and forth constantly, as the hot and cold water hit thermistor  118  from opposite sides. The hot and cold water valves  112  and  98  are rapidly opened and closed in alternating sequence, creating short, alternating bursts of hot and cold water, which keep the average temperature read by the thermistor  118  approximately equal to the temperature setpoint. 
     The alternating bursts of hot and cold water flow from the female cross  120 , through the flow meter  28  and then into the water filter  126 , where they are thoroughly blended and mixed to an even temperature, which varies no more than +/−0.3° F., and which is within 10° F. of the setpoint. The blended water then exits the filter  126  and flows to the female “T”  130 , where it contacts the thermistor  132  (T 2 ). The thermistor  132  sends a temperature reading, in the form of voltage, to the signal conditioner  90 , where it is converted into binary code. This code enters the processor  84  and activates the software  186 . If the water temperature is not within the preset safety range (above 83° F. or below 103° F.) the software  186  causes a signal to be sent to the power drivers  88  which cause the electric coil  140  to be de-energized, closing the failsafe valve  146 . The water flowing from the female “T”  130  is diverted via the tube  142 , through the water connector (female)  170 , through the tube  182 , and to a drain or sink (not shown). The temperature safety indicator light  14  is caused to go out. If the water temperature is within the preset safety range, the software  186  causes a signal to be sent to the power drivers  88  which cause the electric coil  140  to remain energized, keeping the failsafe valve  146  open. The flowing water continues via the tube  148  through the water connector (female)  22 , to the pressure-to-gravity converter  40  via the tube  34 . The temperature safety indicator light  14  is caused to stay on. 
     Via the software  188  in the processor  84 , the temperature of the outgoing water, as read by the thermistor  132  (T 2 ), is constantly checked against and compared to the desired temperature setpoint. So long as the temperature is stable for at least five seconds, an offset is assigned a value equal to the difference between the temperature at the thermistor  132  (T 2 ) and the temperature setpoint. This offset is then added to the setpoint value in the software  184 . Thus, this feedback loop constantly adjusts and fine tunes the temperature reading at the thermistor  118  (T 1 ) so that the desired temperature setpoint (indicated by the digital display  12 ) and the actual temperature of water leaving the system, measured by the thermistor  132  (T 2 ), are equal to each other within 0.3° F. 
     The water leaves the device  2  and enters the pressure-to-gravity converter  40  at the precise temperature desired, regardless of temperature or pressure changes in the building&#39;s water supply. The water flows out the bottom of the casing  42 , through a hole in the end cap  50 , under gravity pressure. The water flow has been set via the needle valve  30  so that the water fills the casing  42  slightly faster than it drains out the hole. Excess water rises to the level of the barbed elbow connector  46 , and vents out to a drain via the tube  48 . Thus, regardless of sudden pressure changes in the building&#39;s water supply, water always flows out the bottom of the casing  42 , to the patient, under a constant, gentle gravity flow. Any pressure differentials only affect the water which vents to the drain via the tube  48 . 
     The patient momentarily closes the clamp  68  to seal off the tube  66 , and the speculum  78  is carefully inserted into the anus. The patient then releases the clamp  68  to start the flow of water into the colon. Under gravity flow, water travels down through the check valve  58  and the tube  66  to the speculum  78  and into the patient. Water pressure can be varied, simply by raising or lowering the pressure-to-gravity converter  42 . 
     While the above description contains many specificities, these should not be construed as limitations on the scope of the invention, but rather as an exemplification of one preferred embodiment thereof. Other variations are possible. For example, the rubber tubing could be made from solid pipe, or the casing could be made from wood or plastic instead of metal. The temperature control device could be made from analog circuitry as opposed to digital. Various types of temperature sensors could be used in place of thermistors. Also, the temperature control device could be used for other applications besides colonic irrigation, such as other medical procedures or industrial processes in which precise temperature control of flowing water is required. Accordingly, the scope of the invention should be determined not by the embodiment illustrated, but by the appended claims and their legal equivalents.