Abstract:
The pneumatic system for intussusception treatment, i.e., invagination of a segment of the intestine into an adjacent segment, includes a pressurized gas supply connected to a series of filters, valves, regulators, and sensors connected to a rectal insertion tube to introduce gas at moderate pressure into the intestine of the patient. A computerized control and monitoring subsystem is included. The system preferably includes a heating system to warm the gas as desired. The system also preferably includes an exhaust portion to relieve internal intestinal pressure as required or desired. The exhaust portion of the system preferably includes a filter to absorb undesirable fecal odors that accompany the exhausted gas. At least the rectal insertion tube and the odor filter may be separable from the remainder of the system for convenient disposal. An alarm may be provided to alert the doctor or medical professional of conditions other than normal.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates generally to medical procedures and equipment, and particularly to a pneumatic system for intussusception treatment (the correction of an everted portion of the intestine) that incorporates various pneumatic and computerized components and controls for optimum safety and efficiency. 
         [0003]    2. Description of the Related Art 
         [0004]    Intussusception is a condition in which a portion of the intestine becomes everted, causing one segment of the bowel to invaginate into a neighboring section so that the bowel commonly appears to have overlapping telescoping sections. The condition is somewhat similar to the telescoping of a larger diameter tube over a tube of smaller diameter. While intussusception is not immediately life threatening, it can be an extremely serious and likely fatal condition if it is left untreated for as little as a few days. This is due to the potential reduction in blood supply to a portion of the affected bowel and resulting necrosis of the tissue, possible bowel perforation or bowel obstruction, and other complications. Intussusception is not common in adults, but is frequently seen in children. 
         [0005]    Accordingly, a number of intussusception treatments have been developed in the past. Earlier developed treatments involved invasive surgery to pull the everted portion of the intestine from the normal portion. Later laparoscopic techniques have been developed to accomplish the same goal. Even more recently, the condition has been treated by pressurizing the interior of the intestine using a relatively slight pressure increase over ambient, e.g., 120 mm of mercury (about 2.32 pounds per square inch), using either hydraulic (salt water) or pneumatic (air or other gas) media. The object is not only to expand the intestine diametrically (this is a side effect), but also to cause the intestine to expand its volume by extending longitudinally in the area of the intussusception, thereby causing the everted portion of the intestine to extend from the normal portion to return to a normal condition. The procedure is frequently called an “air enema,” and is often performed using a sphygmomanometer attached to a Foley catheter. The results are frequently assessed by ultrasonography, by fluoroscopy, or other radiographic technique. The air enema is quicker than a liquid enema, less messy, and safer if the bowel is perforated. 
         [0006]    However, current apparatus for delivering an air enema is generally ad hoc, has insufficient safety measures, and relies upon subjective judgments to determine when the intussusception has been released due to the difficulty of continuous monitoring by sonographic and radiographic techniques. 
         [0007]    Thus, a pneumatic system for intussusception treatment solving the aforementioned problems is desired. 
       SUMMARY OF THE INVENTION 
       [0008]    The pneumatic system for intussusception treatment, i.e., the invagination of a segment of the intestine into an adjacent segment, comprises a supply of pressurized gas (air, carbon dioxide, etc.) connected to a series of filters, valves, regulators, and sensors that are, in turn, connected to a rectal insertion tube to introduce gas at moderate pressure into the intestine of the patient being treated for the condition. The system further includes a computerized control and monitoring subsystem to allow the doctor or medical professional to monitor and adjust the various pressure parameters as desired during the treatment. 
         [0009]    The system preferably includes a heating system to warm the gas media to normal body temperature, i.e., 37° C. or 98.6° F. The system also preferably includes an exhaust portion to relieve internal intestinal pressure according to the treatment regimen. The exhaust portion of the system preferably includes a filter of activated charcoal or other suitable media to absorb undesirable fecal odors that accompany the exhausted gas. At least the rectal insertion tube and the odor filter may be separable from the remainder of the system for convenient disposal after a single use. The computerized subsystem preferably includes audial and/or visual alarm to alert the doctor or medical professional of conditions other than normal. The pneumatic system may further include a fast acting valve (e.g., solenoid valve, etc.) to produce rapid pressure pulses to produce the desired result if and when such a procedure is deemed desirable by the doctor or medical professional administering the treatment. 
         [0010]    These and other features of the present invention will become readily apparent upon further review of the following specification and drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]      FIG. 1  is a schematic illustration of a pneumatic system for intussusception treatment according to the present invention, showing the various pneumatic and electronic components of the system. 
           [0012]      FIG. 2  is a chart showing the relationship between gas pressure and internal volume in the intestine during the operation of the pneumatic system for intussusception treatment according to the present invention. 
           [0013]      FIG. 3  is a graph of the variation of pressure and volume in the intestine when rapid changes in pressure are used to correct the problem, i.e., a “hammering” mode of operation of the pneumatic system for intussusception treatment according to the present invention. 
       
    
    
       [0014]    Similar reference characters denote corresponding features consistently throughout the attached drawings. 
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0015]    The pneumatic system for intussusception treatment provides a non-invasive system for correcting an intussusception disorder, i.e., the invagination of a segment of the intestine into an adjacent segment with accompanying telescoping of the segments. The system is purely pneumatic, and uses no hydraulic fluid. A computerized control and monitoring system is provided with the pneumatic system. 
         [0016]      FIG. 1  of the drawings is a schematic view of the combined pneumatic system and computerized control system, generally indicated by the reference numeral  10 . The basic system  10  includes a gas supply  12 , e.g., a tank of compressed air, carbon dioxide, or other gas. Gas flow is from this gas supply  12  to the left side of  FIG. 1 , through the various components to the patient P to the right side of  FIG. 1 . The gas of the gas supply is a non-toxic element, compound, or mixture, and is non-flammable. The gas may be provided under significant pressure, if desired as the system  10  includes one or more pressure regulators therein, as described further below. The gas may be contained in a pressurized tank or other container, or may be provided by a compressor. 
         [0017]    The gas supply  12  is connected to the inlet end  14  of a gas supply tube  16  via a disconnect fitting  18  (which may be a conventional quick connect pneumatic fitting), permitting the gas supply  12  to be readily connected to and disconnected from the gas supply tube  16 . An inlet filter  20  is preferably installed along the gas supply tube  16  immediately downstream of the inlet end  14  thereof. 
         [0018]    A first or primary valve  22 , e.g., a solenoid or other suitable shutoff valve, is provided downstream of the inlet filter  20 . The valve  22  is normally closed when the system  10  is not in operation, and opens to allow gas to flow from the gas supply  12  through the supply tube  16  during operation of the system. The valve  22  is controlled by a computerized control system comprising a central processing unit (CPU)  24  and interface  26  (e.g., opto-isolators for interfacing high current devices), shown schematically in  FIG. 1 . 
         [0019]    A pressure sensor  28  is installed in the gas supply tube  16  immediately downstream of the primary shutoff valve  22 . This sensor  28  communicates electronically with the interface  26 , and thus with the CPU  24 . The sensor  28  determines the gas pressure developed in the gas supply line  16  by the gas supply  12 , and signals the CPU  24  accordingly as described above. 
         [0020]    The gas then flows to an automatic pressure regulator  30  installed inline along the gas supply line or tube  16  downstream from the pressure sensor  28 . The pressure regulator  30  is set to a predetermined output pressure either manually or under electronic control by the CPU  24 , and automatically regulates or modulates the output pressure to the set predetermined output pressure. The regulator  30  reduces the gas pressure in the supply tube  16  to an output of about 120 mm of mercury, or about 2.32 pounds per square inch, above ambient. This pressure is sufficient to produce the desired result in most cases without danger of rupturing the intestine or causing other damage. The components of the system upstream from the pressure regulator  30  may be referred to as the high pressure side of the system  10 , and the components downstream of the pressure regulator  30  may be referred to as the low pressure side of the system  10 . 
         [0021]    The output pressure of the regulator  30  is monitored by a second pressure sensor  32  downstream of the regulator. This second pressure sensor  32  communicates with the CPU  24  through the interface  26  to confirm that the proper output pressure is being provided from the regulator  30 . In the event that the regulator  30  fails to reduce the pressure sufficiently, or fails in some other manner, the CPU  24  will provide a signal through the interface  26  to close the first shutoff valve  22  (and/or other valves in the system, described further below) and will send an alarm to an audible alarm  34  and/or visual alarm  36  (either or both may be provided with the system  10 ). 
         [0022]    It is preferred that the gas used in the intussusception treatment be warmed to at least approximately normal body temperature in order to avoid lowering the internal body temperature of the patient and to preclude excessive expansion of the gas due to the body of the patient warming the gas during treatment. Accordingly, a heater  38  is installed along the gas supply tube or line  16  at some point, e.g., downstream of the pressure regulator  30  and pressure sensor  32 . The heater  38  is preferably adjusted or set to warm the gas in the supply tube  16  to a temperature of 37° C. or 98.6° F., i.e., normal human body temperature. The output temperature of the heater  38  is preferably adjustable for other temperatures, if desired. A thermostat or temperature sensor and/or controller  40 , preferably a closed loop control system using a proportional-integral-derivative (PID) controller) is installed in the gas supply tube or line  16  immediately adjacent to the output end or side of the heater  38 . The thermostat or controller  40  communicates with the CPU  24  through the interface  26 , and also controls the heater  38 . The CPU  24  may be set to send an alarm signal to either or both of the alarms  34  and/or  36  in the event that the temperature output of the heater  38  becomes either too high or too low. 
         [0023]    The gas, now warmed and at appropriate pressure, then flows from the heater  38  and thermostat  40  through a relief valve  42 . This relief valve  42  functions as a redundant, secondary mechanical safety valve in the event that the pressure output from the regulator  30  exceeds the predetermined maximum and the automated shutdown and release systems fail to function for some reason. The relief valve  42  automatically vents all pressure in the gas supply tube  16  to ambient, in the event of excessive pressure, i.e., that the pressure exceeds 120 mm Hg. As this valve  42  is a mechanical device, it does not necessarily communicate electronically with the CPU  24  and/or interface  26 , although it could be connected through the interface  26  and CPU  24  to provide an alarm in the event that it opens. 
         [0024]    The warmed and pressure-regulated gas then flows from the outlet side of the relief valve  42  to a mass flow controller  44 , which regulates the flow rate of the air or other gas flowing through the supply tube or line  16 . The mass flow controller  44  communicates with and is controlled by the CPU  24  through the interface  26 . The operator of the system adjusts the gas flow through the mass flow controller  44  as desired by means of the computerized control system. 
         [0025]    The system  10  may include a fast acting valve  46  (e.g., solenoid valve or other suitable valve type) installed in line downstream of the mass flow controller  44 . This fast acting valve  46  communicates with the CPU  24  through the interface  26  and functions to rapidly change the pressure downstream from the valve  46 . The purpose of this function is explained further below. A pressure sensor  48  is installed in the gas supply tube or line  16  downstream from the fast acting valve  46 . The sensor  48  also communicates with the CPU  24  through the interface  26 . Control of the fast acting valve  46  by the CPU  24  is in accordance with pressure signals provided from the sensor  48 . 
         [0026]    A flow meter  50  is installed downstream of the fast acting valve  46  and the pressure sensor  48 . The flow meter  50  and the pressure sensor  48  provide the operator of the system with real time information (by means of the CPU  24 ) regarding both the pressure and gas volume measured at the patient P side of the system, the information being displayed graphically on the monitor  66 . 
         [0027]    A rectal insertion tube  54  is releasably connected to the outlet end  52  of the gas supply tube  16  by an appropriate disconnect fitting  56 , which may be similar to the disconnect fitting  18  used to connect the inlet end  14  of the tube  16  to the gas supply  12 . The rectal insertion tube  54  is preferably a disposable unit, i.e., configured for single use, although it may be formed of material providing for sterilization and reuse, if desired. 
         [0028]    A Tee-fitting  58  is installed in the gas supply tube or line  16  between the flowmeter  50  and the outlet end  52  of the gas supply tube. An exhaust gas tube  60  is releasably attached to the stem of the Tee-fitting  58 , and another shutoff valve  62  is installed along the exhaust gas tube  60 . The shutoff valve  62  is normally closed during operation of the system  10 , in order to maintain the desired pressure and/or flow of gas into the intestine of the patient P by means of the rectal insertion tube  54 . The valve  62  is preferably a pinch-type valve, in which a flexible tube or line extends completely through the valve body and is pinched off by a solenoid or other mechanism for closure. This permits the entire exhaust gas tube  60  that passes through the valve  62  to be disposed of after a single use, if desired. The valve  62  communicates electronically with the CPU  24  through the user interface  26 . The valve  62  opens and closes on demand in accordance with commands sent from the CPU  24  to control  62 , and vary the pressure developed within the system  10  as it is provided to the patient P. 
         [0029]    The exhaust gas tube  60  allows excessive gas pressure to be vented from the outlet portion of the system  10 , including the mildly pressurized gas that is delivered into the intestine of the patient P. This gas will of course pick up and absorb unpleasant odors that are a normal byproduct of metabolism. Accordingly, an odor filter  64  is installed in line along the exhaust gas tube  60 , downstream of the valve  62  and preferably at or adjacent to the outlet end of the exhaust gas tube. The odor filter  64  is preferably an activated charcoal filter, but may be of any suitable type, so long as it does not significantly restrict the gas flow therethrough when the valve  62  is open. 
         [0030]    The system  10  is controlled by a human operator through the CPU  24  by means of a visual monitor  66 , keyboard or keypad  68 , and/or computer mouse  70 . The monitor  66  may be a conventional touch screen device, and need not be a full size desktop monitor. A laptop or tablet computer or the like having a suitable monitor may be used. Electrical power for the system and its computerized controls and peripherals is provided by a conventional electrical power supply  72 , e.g., from the power grid or other suitable source. 
         [0031]    The pneumatic system  10  is operated by initializing power to the computer CPU  24 , which provides power to the various valves, controls, heater, etc. of the system through the interface  26 . The first solenoid valve  22  in the system is normally closed at this point, with no gas flowing through the supply tube or line  16 . The parameters desired (e.g., initial gas flow, maximum pressure, rate of pressure rise, temperature, etc.) are entered into the system by means of the computer  24  and its peripherals. The computer  24  stores these parameters until altered or adjusted by the operator. The system  10  remains in standby mode at this point, i.e., the first solenoid valve  22  remains closed until the system  10  has run its initialization routine and checked the various components for readiness, and until the heater  38  has reached the desired operating temperature. Readiness of the system is indicated on the monitor  66 . 
         [0032]    At this point, the patient is readied for the procedure (if not previously accomplished), and the rectal insertion tube  54  is inserted into the patient P. The system  10  is then activated and monitored by the operator. The first valve  22  opens at this point, the remaining valves, sensors, controllers, etc. operating in accordance with the programming of the computer  24  and any changes that might be made by the operator during the procedure. The shutoff valve  62  in the exhaust gas tube or line  60  remains closed. The increase in gas pressure within the intestine results in the expansion of the intestine as its internal volume increases. While this causes the diameter of the intestine to increase, it also produces longitudinal pressure along the intestine that results in the release of the intussusception as the intestine expands longitudinally to remove the invaginated section. 
         [0033]    It will be seen that the volume of the intestine increases proportionally as the internal gas pressure increases, generally in accordance with the graph of  FIG. 2 . The volume increase ΔV is initially relatively rapid with the increase in pressure ΔP. The volume increase ΔV eventually decreases with additional pressure increase, since the compliance of the distended intestine decreases. The gas volume is calculated by integrating the flow rate f, as measured by the flow meter  50 , in accordance with the integral V=∫ t0   t1 fdt. The pressure and volume of gas in the intestine is monitored respectively by the pressure sensor  48  and the flowmeter  50  and transmitted to the computer  24  for monitoring by the operator. A sudden increase in compliance, i.e., a sudden increase in flow measured by the flow meter  50  with either no change or a decrease in pressure measured by the pressure sensor  48 , indicates the intussusception has been released. A sudden increase in flow measured by the flow meter  50  accompanied by an increase in pressure measured by the pressure sensor  48  may indicate a leak in the intestine. 
         [0034]    As these two components  48  and  50  communicate with the computer or CPU  24 , the monitor graphically displays the pressure, the flow rate, and the volume so that the operator may observe such a sudden change in pressure and volume. In addition, the CPU continuously executes a signal processing algorithm to evaluate the instantaneous pressure signals from the pressure sensor  48  and flow readings from the flow meter  50  according to the relationship described in the preceding paragraphs and automatically alerts the operator that the intussusception has been released or that a leak has occurred, either by visual message displayed on the monitor and/or by audio alert. 
         [0035]    The system  10  enables the operator to perform additional procedures in the event that the intussusception is not released by the introduction of steadily increasing pressure and volume into the intestine. The operator may direct the system  10  to perform what may be called a “hammer” mode, in which the gas pressure and volume are varied rapidly to pulse compressed air into the intestine. This is accomplished by adjusting the mass flow controller  44  to allow maximum flow and alternately opening and closing the fast acting valve  46  and the pinch valve  62  of the system, i.e., when the fast acting valve  46  is opened the pinch valve  62  is closed to apply pressure, with the fast acting valve  46  then closing and the pinch valve  62  opening to relieve the pressure. 
         [0036]      FIG. 3  of the drawings illustrates a graph showing the rapid variation in both volume (on the lower scale V) and pressure (on the upper scale) over a short span of time. It will be seen that as the pressure increases, as shown by the series of four “sawtooth” pulses P 1  through P 4  along the upper pressure scale P, the volume increases correspondingly, as shown by the series of volume pulses V 1  through V 4  along the lower volume scale V. The intestinal volume drops to a constant level between each expansion, as the pressure drops due to the opening of the fast acting valve  46 . The graph of  FIG. 3  indicates that the intestinal volume increases to a maximum level during each of the first three volume pulses or increases V 1  through V 3 . However, the final volume pulse or increase V 4  is somewhat larger than the previous pulses V 1  through V 3 . The only way that this can occur is if the internal volume of the intestine suddenly expands due to the release of the intussusception. Accordingly, the final volume pulse V 4  indicates that the intussusception has been released, and no further pressure pulses (and resulting volume increases) are required. The fast acting valve  46  in the gas supply tube or line  16  may then be closed and the shutoff valve  62  in the exhaust gas tube or line  60  opened to relieve all pressure within the intestine of the patient P. The intestinal gas then flows outward through the exhaust gas tube or line  60  and out the odor filter  64 . The preferably single use, disposable elements of the system  10 , i.e., at least the rectal insertion tube  54 , the exhaust gas tube  60  that passes through the pinch valve  62 , and the odor filter  64  may be disposed of once the procedure has been completed as described above. 
         [0037]    It will be understood that, in use, the system  10  may be used in a single stage approach, setting the output pressure to 120 mm Hg to see if the intussusception can be released by pneumatic treatment. Alternatively, the system  10  may be used in multiple steps, e.g., beginning by setting the output pressure at 60 mm Hg, releasing the gas from the patient&#39;s intestine if the intussusception has not been corrected, then increasing the output pressure in 20 mm Hg steps up to 120 mm Hg, so that the intussusception may be corrected using the least amount of pressure required. If the intussusception cannot be released at 120 mm Hg, even with pulsed compressed air in the hammer mode, then surgical invention may be required. 
         [0038]    It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims.