Systems, devices and methods for draining and analyzing bodily fluids

Abstract

To provide a catheter system which prevents an air lock from being formed in a drainage tube, removes the air lock when it is formed, and improves the accuracy of measuring a urine volume by an automated method.SOLUTION: A catheter system includes a catheter having at least one opening at or near a distal end, a barb in fluid communication with a proximal end of the catheter, a drainage tube in fluid communication with the at least one opening, a vent tube in fluid communication with the barb, a one way valve positioned in line with the vent tube and proximal to the barb, and a controller in communication with the one way valve, wherein the controller is controlled such that application of negative pressure to the drainage tube causes the one way valve to open and fluid to pass through the vent tube.SELECTED DRAWING: Figure 11B

Description

[Technical Field]

[0001] This application claims priority to U.S. Provisional Application No. 62 / 448,237, filed January 19, 2017, and U.S. Provisional Application No. 62 / 503,209, filed May 8, 2017, and U.S. Provisional Application No. 62 / 563,546, filed September 26, 2017, each of which is incorporated by reference in its entirety. This application is also related to International Patent Application Nos. PCT / US2011 / 043570, filed July 11, 2011, PCT / US2012 / 028071, filed March 7, 2012, PCT / US2016 / 060365, filed November 3, 2016, PCT / US2015 / 052716, filed September 28, 2015, PCT / US2014 / 044565, filed June 27, 2014, PCT / US2015 / 010530, filed January 7, 2015, and PCT / US2016 / 060365, filed November 3, 2016, each of which is incorporated herein by reference as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference.

[0002] The present invention relates to the field of medical devices, particularly devices that assist in bladder emptying, measure various urinary parameters such as urine output and oxygen tension, urinary conductance and urine specific gravity, monitor renal function, analyze urinary parameters including urine volume, including the presence of infection, and track and / or manage fluid administration. The present invention further relates to medical devices that can sense physiological data based on sensors integrated into catheters adapted to reside in either the urinary tract, gastrointestinal tract, rectal location, preperitoneal, pleural cavity, or other body cavities.

[0003] All publications and patent applications mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference. [Background technology]

[0004] It is estimated that 10% of all hospitalized and nursing care patients receive an indwelling urinary catheter. Nearly all critically ill patients receive one indwelling urinary catheter, and in the ICU, it is used to monitor urine output hourly. The amount of urine produced is an indicator of fluid status and renal function. However, numerous sources of error can cause erroneous measurement of this important indicator.

[0005] The most common device used to drain the bladder is the Foley catheter. Since its introduction, the design of a flexible tube with a fixed balloon and small holes that allow urine to drain through a central lumen has remained largely unchanged. However, current Foley catheter designs have been found to potentially leave a large residual volume in the bladder, e.g., greater than 50 mL in supine patients. See Fallis, Wendy M. Indwelling Foley Catheters: Is the Current Design a Source of Erroneous Measurement of Urine Output? Critical Care Nurse 25.2 (2005):44-51. In one study, the average residual volume was 96 mL in the ICU and 136 mL in the general ward. See Garcia et al., Traditional Foley Drainage Systems—Do They Drain the Bladder?, J Urol. 2007 Jan;177(l):203-7; discussion 207. There is often a large amount of residual urine in the drainage tube connecting the Foley catheter to the drainage bag, or elsewhere in the drainage system.

[0006] Residual urine in the bladder and drainage tube is the result of large air bubbles (air locks) that form in the tube and block the flow of urine from the bladder to the drainage bag. As a result, it is routine procedure for nurses to manipulate the drainage tube before measuring urine output, which helps empty the tube. In the ICU, this is a highly repetitive and inaccurate process, as measurements are taken hourly. There is a need for more accurate and automated urine output measurements.

[0007] Additionally, within the urine collection system, there is an opportunity to measure and analyze urine parameters.

[0008] In addition to improving urine output measurement and urine parameter analysis, the urinary drainage catheter itself provides an untapped opportunity to detect, collect, and analyze additional patient parameters.

[0009] Additionally, many types of medical devices are designed to control the treatment and / or maintenance of a patient. For example, a ventilator can control, among other things, a patient's breathing rate, volume, and / or gas mixture. An IV (intravenous delivery) can deliver fluids and / or other substances, such as medications, to a patient. Other devices include those that can deliver medicines or perform other actions. These types of medical devices can be tightly controlled via various settings, etc. A nurse or other practitioner can check various patient parameters and adjust medical device settings accordingly. There is a need for a controller that automatically or semi-automatically uses patient parameters to control the settings of a treatment device. Summary of the Invention [Means for solving the problem]

[0010] Widely used, low-cost, and easily placed by medical professionals, Foley-type catheters can be used as a vehicle to derive important diagnostic information by modifying and / or adding functionality to Foley-type catheters. The technology disclosed herein provides for the delivery of highly resolved, previously unavailable diagnostic information, such as can be derived from a Foley-type catheter equipped with intra-abdominal pressure (and other) sensing capabilities.

[0011] Additionally, the development of an airlock has been found to significantly distort intra-abdominal pressure measurements. Furthermore, an unemptied bladder can also adversely affect intra-bladder pressure measurements. The techniques disclosed herein also provide for the detection and elimination of airlocks during intra-abdominal pressure measurements or other settings, as well as more complete bladder drainage.

[0012] The technology disclosed herein aims to more effectively drain the bladder, prevent airlocks from forming in the drainage tube and causing urine to escape from the drainage tube, and increase the accuracy of measuring urine volume in an automated manner. The disclosed technology also aims to incorporate additional measurements of urine, including oxygen tension, conductance, and specific gravity, gas pressure, turbidity, infection, sediment, etc., to improve monitoring of fluid status, renal function, and other important patient parameters.

[0013] The disclosed technology also relates to Foley-type catheters that sense physiological data from a patient's bladder and / or urinary tract, including, among other things, physiological data gathered through high-fidelity pressure sensing and conversion to a signal suitable for processing. In some embodiments, the pressure-sensing Foley-type catheter may further be capable of sensing clinically important temperature and analytes. Examples of physiological parameters that a sensing Foley catheter system may measure (both time-specific measurements and trends of values ​​over time) include urine volume, respiratory rate, heart rate, heart rate variability, stroke volume, stroke volume variability, intra-abdominal pressure (IAP), tissue oxygenation, tissue gas content, pulse transit time, pulmonary blood volume variation, body temperature, blood content, and other patient parameters.

[0014] One embodiment of a drainage assembly configured to prevent the buildup of negative pressure may generally include an elongated catheter having a first end configured for insertion into a body cavity. The catheter may have at least one opening at or near the first end in fluid communication with a catheter lumen defined therethrough, a drainage lumen in fluid communication with a second end of the catheter, a reservoir in fluid communication with the drainage lumen, and a vent mechanism in fluid communication with the drainage lumen and the positive pressure lumen. A valve may be disposed within the vent mechanism and configured to remain in a closed position until a first pressure level in the drainage lumen drops to a second pressure level, at which point the valve moves to an open position. A vent may also be disposed in fluid communication with the valve, the vent mechanism configured to prevent wetting of the vent from liquid in the drainage lumen, and a controller in communication with the reservoir configured to determine the amount of fluid collected in the reservoir.

[0015] In another embodiment, a drainage assembly configured to prevent the buildup of negative pressure may generally include an elongated catheter having a first end configured for insertion into a body cavity, the catheter having at least one opening at or near the end in fluid communication with a catheter lumen defined therethrough. A drainage lumen is in fluid communication with a second end of the catheter, a positive pressure lumen in fluid communication with the drainage lumen, a reservoir in fluid communication with the drainage lumen, and a vent mechanism coupled to the drainage lumen, the vent mechanism configured to inhibit wetting of the vent from fluid in the drainage lumen. A controller may be in communication with the reservoir, the controller may be configured to determine the amount of fluid collected in the reservoir, and also include a valve configurable between a closed position and an open position, the valve moving from the closed position to the open position when a first pressure level applied to the valve decreases to a second pressure level in the reservoir.

[0016] Certain patient parameters that can be measured and / or determined by the disclosed technology are affected and / or impacted by the patient's treatment with a medical device. For example, a patient's urine volume, respiratory rate, heart rate, stroke volume, stroke volume variation, intra-abdominal pressure (IAP), tissue oxygenation, tissue gas volume, body temperature, blood volume, and other patient parameters may be affected and / or impacted by medical treatment. Some examples of medical treatments controlled by medical devices include respiratory rate and content controlled by a ventilator, IV rate and content controlled by an IV drip controller, drug delivery controlled by a drug delivery device or IV controller, urinary pumps, ascites volume controlled by a drainage pump, and other treatments controlled by other medical devices.

[0017] One embodiment of a system for analyzing bodily fluids generally includes an elongate catheter having an expandable balloon located at or near a distal end of the catheter and further defining one or more openings proximate the balloon, a proximal end of the catheter, a venting mechanism configured to allow air to pass therethrough when negative pressure is applied to the venting mechanism, a first lumen coupled to the venting mechanism and in fluid communication with the one or more openings, a second lumen in fluid communication with the balloon, a reservoir coupled to the proximal end of the first lumen and in fluid communication with the one or more openings, and a controller configured to connect to the reservoir and programmed to control the pressure in the first lumen, further programmed to monitor urine output received in the reservoir from a patient and to determine intra-abdominal pressure of the patient based in part on changes in pressure in the balloon, and the controller is further configured to store patient data.

[0018] In one exemplary method for analyzing one or more body parameters from a patient, the method may generally include positioning an elongate catheter having an expandable balloon located near or distal to a distal end of the catheter within an at least partially filled body lumen; a body fluid lumen that receives urine from one or more openings defined along the catheter proximate to the balloon and further receives body fluid within a reservoir outside the body cavity and is in fluid communication with the one or more openings; a venting mechanism that expels air via a venting mechanism in communication with the fluid lumen when negative pressure is applied to the fluid lumen and analyzes the amount of urine contained within the reservoir via a controller programmed to control the negative pressure; determining the patient's intra-abdominal pressure based in part on changes in pressure within the balloon; and storing one or more parameters of patient data via the controller.

[0019] Some embodiments of the sensing Foley catheter system include a loop controller that receives one or more data regarding patient parameters and uses this information to control one or more medical treatment devices. The loop controller can be integrated with devices that measure patient parameters, medical devices, or both.

[0020] Pressure-measuring balloons on catheters, such as those disclosed in International Patent Application No. PCT / US14 / 44565 entitled "Sensing Foley Catheter," which is incorporated herein by reference in its entirety, are examples of devices for measuring patient parameters. Additional embodiments are disclosed herein. Sensing Foley catheter systems include pressure-measuring balloons and / or other sensors and the ability to measure urine output and content to determine patient parameters such as urine output, IAP, respiratory rate, heart rate, stroke volume, tissue oxygenation, urine composition, body temperature, and other patient parameters.

[0021] Other parameters that may be measured and / or determined via a sensing Foley-type catheter include urine specific gravity and pulse pressure variability, which may be used to assist in the control of medical treatment devices such as ventilators and / or infusion and / or hydration devices.

[0022] Urine specific gravity is a measure of the number and weight of solute particles in urine. The normal range is approximately 1.010 to 1.030. A higher reading may indicate dehydration or other conditions. A lower reading may indicate fluid overload or other conditions. Measurements can be made with sensors in a sensing Foley catheter. Measurements may indicate an increase (in the case of dehydration) or decrease (in the case of fluid overload) infusion rate to the patient. Measurements may also indicate changes in ventilation parameters, drug infusion, etc.

[0023] Pulse pressure variability can be a predictor of fluid responsiveness to medical devices such as ventilators and / or fluid infusion devices. A sensing Foley catheter can record the pressure waveform, allowing a controller to identify maximum and minimum pressure pulses that coincide with the respiratory cycle. The controller can calculate pulse pressure variability. Pulse pressure variability helps determine whether a particular patient will respond to fluid therapy. The controller can also use pulse pressure variability to control therapy in a feedback loop. If pulse pressure variability is high, the patient may need more fluid. If pulse pressure variability is low, less fluid will be needed.

[0024] A sensing Foley catheter system can measure cardiac activity via intrabladder pressure sensing. Sensing Foley catheters can measure respiratory and cardiac activity, and because a patient's respiratory rate and heart rate may be similar in frequency, a patient's respiratory measurements can distort cardiac measurements. To overcome this problem, some controller embodiments pause the ventilator at the end of one or more inspiration points and / or pause the ventilator at the end of one or more expiration points (each time for only a few seconds, e.g., 1-3 seconds, or e.g., 1-4 seconds), thereby capturing cardiac waveforms without respiratory distortion. Capturing detailed cardiac waveforms in this manner allows the controller to determine stroke volume variation (SVV), which can be useful in detecting sepsis and preventing fluid overload. Alternatively, the patient may be asked to hold their breath at inspiration and / or expiration points.

[0025] In another embodiment, a catheter system may generally include a catheter having at least one opening near or at the distal end of the catheter, a barb in fluid communication with the proximal end of the catheter, a drainage tube in fluid communication with the at least one opening, and a vent tube in fluid communication with the barb. A one-way valve may be positioned in line with the vent tube and proximal to the barb, and a controller may be in communication with the one-way valve, the controller being programmed to apply negative pressure to the drainage tube, thereby opening the one-way valve and allowing fluid to pass through the vent tube.

[0026] In another embodiment, a method for draining fluid may generally include positioning a catheter system near a subject's body, the catheter having at least one opening near or distal to the distal end of the catheter, a barb in fluid communication with the proximal end of the catheter, and a drainage tube in fluid communication with the at least one opening. A controller in communication with a one-way valve can be activated when the one-way valve is in line with the vent tube and in fluid communication with the barb, the one-way valve further positioned proximal to the barb. Applying negative pressure to the drainage tube opens the one-way valve and allows fluid to pass through the vent tube.

[0027] The novel features of the invention are set forth. A better understanding of the features and advantages of the present invention will be obtained by reference to the following detailed description that sets forth illustrative embodiments, in which the principles of the invention are utilized, and the accompanying drawings of which: [Brief explanation of the drawings]

[0028] [Figure 1] FIG. 1 illustrates an embodiment of a sensing Foley-type catheter. [Figure 2] FIG. 2 shows an example of respiratory rate sensing data. [Figure 3] FIG. 3 shows a detailed portion of the respiratory profile. [Figure 4] FIG. 4 shows an example of heart rate and relative cardiac output sensing data. [Figure 5] FIG. 5 shows data on relative cardiac output sensing during leg lift exercise in humans. [Figure 6] FIG. 6 shows an example of peritoneal sensing data. [Figure 7] FIG. 7 shows an example of peritoneal sensing data. [Figure 8] FIG. 8 shows the relationship between intra-abdominal pressure, respiratory wave pressure, and cardiac pressure. [Figure 9] FIG. 9 provides a flow diagram of an embodiment of this method. [Figure 10A] FIG. 10A illustrates an embodiment of a sensing Foley catheter system. [Figure 10B] FIG. 10B illustrates the temperature logic used in the controller of some embodiments. [Figure 10C] FIG. 10C shows a detailed view of the airlock cleaning mechanism and fluid collection and analysis system of FIG. 10A. [Figure 10D] FIG. 10D shows the disposable components of an embodiment of a sensing Foley catheter system. [Figure 11A] FIG. 11A illustrates various embodiments of a sensing Foley catheter system. [Figure 11B] FIG. 11B illustrates various embodiments of a sensing Foley catheter system. [Figure 11C] FIG. 11C illustrates various embodiments of a sensing Foley catheter system. [Figure 11D] FIG. 11D shows an embodiment of a vent tube. [Figure 11E] FIG. 11E shows another embodiment of a sensing Foley catheter system. [Figure 11F] FIG. 11F shows a graphical representation of the valve opening cycle. [Figure 12A] FIG. 12A shows another embodiment of a sensing Foley catheter system. [Figure 12B] FIG. 12B illustrates another embodiment of a sensing Foley catheter system. [Figure 13] FIG. 13 illustrates another embodiment of a sensing Foley catheter system. [Figure 14A] FIG. 14A shows an embodiment of a collapsible drainage tube within a kink-resistant tube. [Figure 14B] FIG. 14B shows an embodiment of a collapsible drainage tube within a kink-resistant tube. [Figure 15] FIG. 15 shows an example of a cleaning mechanism for a sensing Foley catheter system. [Figure 16] FIG. 16 shows an example of a cleaning mechanism for a sensing Foley catheter system. [Figure 17] FIG. 17 shows an embodiment of a sensing Foley catheter system with a drainage tube that includes a gas sampling lumen. [Figure 18] FIG. 18 shows an active vent system with a vent and a pump. [Figure 19] FIG. 19 shows an embodiment of a sensing Foley catheter system with additional vents for pressure relief and sterility. [Figure 20] FIG. 20 shows an embodiment of a sensing Foley catheter system with a pressure relief vent and relief valve. [Figure 21] FIG. 21 shows an embodiment of a collection container, chamber, or cassette that may be included in a sensing Foley catheter system for detecting bacteria, blood, and / or other substances in urine using UV / light spectroscopy. [Figure 22] FIG. 22 shows the various absorption wavelengths of E. coli, red blood cells, and plasma in urine. [Figure 23] FIG. 23 shows an embodiment of a cassette that includes baffles or flaps. [Figure 24] FIG. 24 shows a graph illustrating a pressure balloon priming method according to some embodiments. [Figure 25] FIG. 25 shows a graph illustrating a pressure balloon priming method according to some embodiments. [Figure 26] FIG. 26 shows a flow chart of possible logic in various embodiments of the present invention. [Figure 27] FIG. 27 shows a flow chart of possible logic in various embodiments of the present invention. [Figure 28] FIG. 28 shows a flow chart of possible logic in various embodiments of the present invention. [Figure 29] FIG. 29 shows an embodiment of a sensing Foley catheter system with a loop controller in a patient environment. [Figure 30]FIG. 30 shows an embodiment of a sensing Foley catheter system with a loop controller in a patient environment. [Figure 31] FIG. 31 shows an embodiment of a sensing Foley catheter system with a loop controller in a patient environment. [Figure 32] FIG. 32 shows an embodiment of a sensing Foley catheter system with a loop controller in a patient environment. [Figure 33] Figure 33 shows the details of the loop controller with the possible input parameters and output actions. [Figure 34] FIG. 34 is a plot of ultrasound and pressure measurements of volume divergence. [Figure 35] FIG. 35 shows the distal end of an embodiment of a sensing Foley catheter. [Figure 36] FIG. 36 shows an embodiment of a filter within a balloon. [Figure 37] FIG. 37 shows an embodiment of a filter within a balloon with the balloon inflated. [Figure 38] FIG. 38 shows an embodiment of a filter within a balloon with the balloon deflated. [Figure 39] FIG. 39 shows an embodiment of a filter within a balloon. [Figure 40] FIG. 40 shows an embodiment of a filter within a balloon. [Figure 41] FIG. 41 shows an embodiment of a filter within a balloon. [Figure 42] FIG. 42 shows an embodiment of a filter within a balloon. [Figure 43] FIG. 43 shows an embodiment of a filter within a balloon. [Figure 44] FIG. 44 shows an embodiment of a filter within a balloon. [Figure 45] FIG. 45 shows an embodiment of a filter within a balloon. [Figure 46] FIG. 46 shows an embodiment of a filter within a balloon. [Figure 47]FIG. 47 shows an embodiment of a balloon with multiple access lumens. [Figure 48] FIG. 48 shows an embodiment of a balloon. [Figure 49] FIG. 49 shows an embodiment of a balloon. [Figure 50] FIG. 50 shows various embodiments of balloon catheters with gas permeable membranes. [Figure 51] FIG. 51 shows various embodiments of balloon catheters with gas permeable membranes. [Figure 52] FIG. 52 shows various embodiments of balloon catheters with gas permeable membranes. [Figure 53] FIG. 53 shows various embodiments of balloon catheters with gas permeable membranes. [Figure 54] FIG. 54 shows a controller for measuring gas content via a balloon catheter. [Figure 55] FIG. 55 is a schematic diagram of a gas measuring catheter / controller system. [Figure 56] FIG. 56 is a schematic diagram of a gas measuring catheter / controller system. [Figure 57A] FIG. 57A shows an embodiment of a gas measurement add-on component. [Figure 57B] FIG. 57B shows an embodiment of a gas measurement add-on component. [Figure 58A] FIG. 58A shows a table listing parameter combinations that allow for potential signatures to distinguish acute kidney injury and UTI based on patient parameters. [Figure 58B] FIG. 58B shows a table listing parameter combinations that allow possible signatures for distinguishing between acute kidney injury, sepsis, and acute respiratory distress syndrome based on patient parameters. [Figure 59] Figure 59 shows the pressure characteristic curve in the collection chamber during airlock clearance. [Figure 60]FIG. 60 is a block diagram of a data processing system that can be used in any embodiment of the present invention. [Figure 61] FIG. 61 shows alternative wavelengths that can be used to distinguish between red blood cells and / or plasma / white blood cells. [Figure 62] Figure 62 shows the urine output data immediately after administration of a diuretic. [Figure 63A] FIG. 63A shows how the smaller diameter lumen compares to the larger diameter lumen in the vent / filter region. [Figure 63B] FIG. 63B shows how the smaller diameter lumen compares to the larger diameter lumen in the vent / filter region. [Figure 64] Figure 64 shows a curved barb region. [Figure 65] FIG. 65 shows an embodiment of a sensing Foley catheter system with a vent tube. [Figure 66] FIG. 66 shows a sensing Foley catheter system with a separate positive pressure vent tube. [Figure 67] FIG. 67 shows an enlarged view of the barb region of FIG. [Figure 68] FIG. 68 shows the barb regions of various embodiments of a sensing Foley catheter system. [Figure 69] FIG. 69 shows the barb regions of various embodiments of a sensing Foley catheter system. [Figure 70] FIG. 70 shows the barb regions of various embodiments of a sensing Foley catheter system. [Figure 71] FIG. 71 shows the barb region of various embodiments of a sensing Foley catheter system. [Figure 72] FIG. 72 shows the barb regions of various embodiments of a sensing Foley catheter system. [Figure 73A] FIG. 73A shows the barb region of various embodiments of a sensing Foley catheter system. [Figure 73B]FIG. 73B shows the barb region of various embodiments of a sensing Foley catheter system. [Figure 74] FIG. 74 shows the barb regions of various embodiments of a sensing Foley catheter system. [Figure 75A] FIG. 75A shows the barb region of various embodiments of a sensing Foley catheter system. [Figure 75B] FIG. 75B shows the barb region of various embodiments of a sensing Foley catheter system. [Figure 76] FIG. 76 shows the barb regions of various embodiments of a sensing Foley catheter system. [Figure 77A] FIG. 77A shows the barb region of various embodiments of a sensing Foley catheter system. [Figure 77B] FIG. 77B shows the barb region of various embodiments of a sensing Foley catheter system. [Figure 78] FIG. 78 shows the barb region of various embodiments of a sensing Foley catheter system. [Figure 79] FIG. 79 shows the barb region of various embodiments of a sensing Foley catheter system. [Figure 80A] FIG. 80A shows the barb region of various embodiments of a sensing Foley catheter system. [Figure 80B] FIG. 80B shows the barb region of various embodiments of a sensing Foley catheter system. [Figure 81] FIG. 81 shows the barb region of various embodiments of a sensing Foley catheter system. [Figure 82A] FIG. 82A shows the barb region of various embodiments of a sensing Foley catheter system. [Figure 82B] FIG. 82B shows the barb region of various embodiments of a sensing Foley catheter system. [Figure 83]FIG. 83 shows the barb region of various embodiments of a sensing Foley catheter system. [Figure 84] FIG. 84 shows the barb region of various embodiments of a sensing Foley catheter system. [Figure 85] FIG. 85 shows the barb region of various embodiments of a sensing Foley catheter system. [Figure 86] FIG. 86 shows the barb regions of various embodiments of a sensing Foley catheter system. [Figure 87] FIG. 87 shows an embodiment of a sensing Foley catheter system with an internal vent tube. [Figure 88] FIG. 88 shows an embodiment of a sensing Foley catheter system with an internal vent tube. [Figure 89] FIG. 89 shows an embodiment of a sensing Foley catheter system with an internal vent tube and positive pressure tube. [Figure 90] FIG. 90 shows an embodiment of a sensing Foley catheter system with an internal vent tube. [Figure 91A] FIG. 91A shows an embodiment of a sensing Foley catheter system with an internal vent tube. [Figure 91B] FIG. 91B shows an embodiment of a sensing Foley catheter system with an internal vent tube. [Figure 92A] FIG. 92A shows several embodiments of the drainage lumen. [Figure 92B] FIG. 92B shows several embodiments of the drainage lumen. [Figure 93A] FIG. 93A shows another embodiment of a drainage lumen. [Figure 93B] FIG. 93B shows another embodiment of the drainage lumen. [Figure 93C] FIG. 93C shows another embodiment of the drainage lumen. [Figure 93D] FIG. 93D shows another embodiment of the drainage lumen. [Figure 93E]FIG. 93E shows another embodiment of the drainage lumen. [Figure 94A] FIG. 94A shows an embodiment of a sensing Foley catheter system in which the pressure sensor is on a separate catheter. [Figure 94B] FIG. 94B shows an embodiment of a sensing Foley catheter system in which the pressure sensor is on a separate catheter. [Figure 94C] FIG. 94C shows an embodiment of a sensing Foley catheter system in which the pressure sensor is on a separate catheter. [Figure 95A] FIG. 95A shows an embodiment of a sensing Foley catheter system with a bubble reduction mechanism. [Figure 95B] FIG. 95B shows an embodiment of a sensing Foley catheter system with a bubble reduction mechanism. [Figure 95C] FIG. 95C shows an embodiment of a sensing Foley catheter system with a bubble reduction mechanism. [Figure 96A] FIG. 96A shows an embodiment of a sensing Foley catheter system with a bubble reduction mechanism. [Figure 96B] FIG. 96B shows an embodiment of a sensing Foley catheter system with a bubble reduction mechanism. [Figure 96C] FIG. 96C shows an embodiment of a sensing Foley catheter system with a bubble reduction mechanism. [Figure 96D] FIG. 96D shows an embodiment of a sensing Foley catheter system with a bubble reduction mechanism. [Figure 97A] FIG. 97A shows an embodiment of a sensing Foley catheter system with a bubble reduction mechanism. [Figure 97B] FIG. 97B shows an embodiment of a sensing Foley catheter system with a bubble reduction mechanism. [Figure 97C] FIG. 97C shows an embodiment of a sensing Foley catheter system with a bubble reduction mechanism. [Figure 97D]FIG. 97D shows an embodiment of a sensing Foley catheter system with a bubble reduction mechanism. [Figure 98A] FIG. 98A shows an embodiment of a sensing Foley catheter system with a bubble reduction mechanism. [Figure 98B] FIG. 98B shows an embodiment of a sensing Foley catheter system with a bubble reduction mechanism. [Figure 98C] FIG. 98C shows an embodiment of a sensing Foley catheter system with a bubble reduction mechanism. [Figure 98D] FIG. 98D shows an embodiment of a sensing Foley catheter system with a bubble reduction mechanism. [Figure 99A] FIG. 99A shows an embodiment of a sensing Foley catheter system with a bubble reduction mechanism. [Figure 99B] FIG. 99B shows an embodiment of a sensing Foley catheter system with a bubble reduction mechanism. [Figure 99C] FIG. 99C shows an embodiment of a sensing Foley catheter system with a bubble reduction mechanism. [Figure 100A] FIG. 100A shows an embodiment of a sensing Foley catheter system with a bubble reduction mechanism. [Figure 100B] FIG. 100B illustrates an embodiment of a sensing Foley catheter system with a bubble reduction mechanism. [Figure 100C] FIG. 100C illustrates an embodiment of a sensing Foley catheter system with a bubble reduction mechanism. [Figure 101A] FIG. 101A shows an embodiment of a sensing Foley catheter system with a bubble reduction mechanism. [Figure 101B] FIG. 101B shows an embodiment of a sensing Foley catheter system with a bubble reduction mechanism. [Figure 101C] FIG. 101C shows an embodiment of a sensing Foley catheter system with a convoluted flow path in the collection reservoir. [Figure 101D]FIG. 101D shows an embodiment of a sensing Foley catheter system with a convoluted flow path in the collection reservoir. [Figure 101E] FIG. 101E shows an embodiment of a sensing Foley catheter system with a convoluted flow path in the collection reservoir. [Figure 102] FIG. 102 shows the pressure waveform and its decay using a pressure balloon. [Figure 103] FIG. 103 shows sample clinical data illustrating how ECG can be used to remove noise from cardiac signals. [Figure 104] FIG. 104 shows sample clinical data illustrating stroke volume variation analysis using the model waveforms. [Figure 105A] FIG. 105A shows a view of the cassette-side components of an embodiment of a sealing mechanism for some lumens between the cassette and the controller / monitor. [Figure 105B] FIG. 105B shows a view of the cassette-side components of an embodiment of a sealing mechanism for some lumens between the cassette and the controller / monitor. [Figure 106] FIG. 106 shows the controller-side components of the embodiment of the sealing mechanism shown in FIGS. 105A and 105B. [Figure 107A] FIG. 107A shows a diagram of an embodiment of a lumen connection sealing mechanism between the cassette and the controller. [Figure 107B] FIG. 107B shows a diagram of an embodiment of a lumen connection sealing mechanism between the cassette and the controller. [Figure 108] FIG. 108 shows an embodiment of a lumen connection sealing mechanism on the back of the cassette. [Figure 109] FIG. 109 shows a cross-sectional view of the lumen connection sealing mechanism on the back of the cassette. [Figure 110] FIG. 110 shows a dimensional drawing of the cassette-side components of an embodiment of a sealing mechanism for some of the lumens between the cassette and the controller / monitor. [Figure 111]FIG. 111 shows a force view of the cassette-side components of an embodiment of a sealing mechanism for several lumens between the cassette and the controller / monitor. [Figure 112] FIG. 112 shows an embodiment that includes a venting mechanism that can be added to any urinary drainage system that includes a sampling port. [Figure 113] FIG. 113 shows an embodiment including a pump / argor. [Figure 114] FIG. 114 shows an embodiment in which the drainage tube includes a coiled or compressed section. [Figure 115A] FIG. 115A shows an embodiment of a barb that includes a tube seating mechanism. [Figure 115B] FIG. 115B shows an embodiment of a barb that includes a tube seating mechanism. DETAILED DESCRIPTION OF THE INVENTION

[0029] Preferred embodiments of the present invention are described in detail herein. However, alternative embodiments of various features of the device are possible. Examples of these embodiments are provided below, but the scope of the present invention is not limited to these particular configurations.

[0030] Sensing Foley Catheter

[0031] 1 illustrates an embodiment of a sensing Foley catheter and some of its features. The catheter can be understood to have various sections, depending on the placement of the catheter when inserted into a human subject, such as a proximal section that remains outside the subject, a central section or section that remains in the urethra, and a distal section that remains in the urinary bladder.

[0032] Various internal lumens traverse the length of the catheter, including air or fluid lumens communicating with the bladder retention balloon 104 and retention balloon port 118. A urinary drainage lumen has an internal distal opening or openings 106, an opening at the bladder portion of the catheter, and a proximal end 114 of the catheter. The urinary drainage lumen may be connected to a urinary drainage tube that carries urine to a collection container. The urinary drainage tube may be separate from or integral with the sensing Foley catheter. In some embodiments, the bladder drainage lumen and distal opening may also function as an infusion conduit through which medications or heated or cooled fluids may be infused. Analyte sensors (not shown) or temperature sensors (not shown) may be located in either the urethral portion of the catheter or the indwelling portion of the catheter. Electrical or fiber optic leads are located in the lumens that allow communication of sensed signals between the distally located sensor and the proximal portion of the catheter for further communication with a data processing device or controller.

[0033] An inflatable pressure-sensing balloon 108 (or a pressure-sensing membrane positioned across the opening) may be positioned at or near the distal end of the catheter. Pressure-sensing balloon or membrane embodiments may be understood to comprise a pressure interface having a distal-facing surface exposed to pressure from within the bladder and a proximal-facing surface exposed to the proximal fluid column. The pressure-sensing balloon or membrane is in fluid communication with a fluid column or lumen that is in fluid communication with a pressure port 116 at or near the proximal end of the catheter. Fluid column embodiments (filled with either a liquid or gas) may comprise a dedicated lumen or a shared lumen.

[0034] In some embodiments, the temperature sensor may be at or near the distal end of the catheter. The temperature port 110 may include a temperature communication line 112 that connects the temperature sensor to a display, connector, and / or controller.

[0035] Although Figure 1 shows the proximal end of the catheter including multiple separate ports, some or all of the ports may be combined into a single port or into a urinary drainage line that runs to a urinary drainage system and / or controller. Other lumens and / or ports may also be present.

[0036] Pressure-based physiological parameters that a sensing Foley catheter system may sense and / or determine via a controller based on sensed parameters may include, by way of example, abdominal pressure, respiratory rate, heart rate, relative pulmonary tidal volume profile, cardiac output, relative cardiac output, and absolute cardiac output. Some embodiments of Foley catheters may further comprise a temperature sensor, one or more analyte sensors, electrodes, and / or light source and sensor pairs. Such further equipped embodiments may deliver other forms of physiological data, such as blood pressure, oxygen saturation, pulse oximetry, EKG, and capillary filling pressure.

[0037] Embodiments of a sensing Foley catheter may be capable of sensing any one or more of a number of clinically relevant parameters, examples of which include: urine pH, urine oxygen content, urine nitrate content, respiratory rate, heart rate, bladder wall or urethral wall perfusion pressure, temperature within the bladder or urethra, electrocardiogram via sensors on the bladder wall or urethra, respiratory volume, respiratory pressure, peritoneal pressure, urine glucose, blood glucose and / or bladder mucosa via the urethral mucosa, urine protein, urine hemoglobin, blood pressure.

[0038] In some embodiments, the catheter is capable of sensing multiple parameters, although some embodiments may be limited to a single parameter for focused applications (e.g., respiratory rate in a patient with respiratory distress).

[0039] The disclosed technology can capture high-resolution temporal profiles of intra-abdominal pressure (pressure as a function of time) from within the bladder and convert and process them into distinct pressure profiles that can be assigned to specific physiological sources, including peritoneal pressure, respiratory rate, and heart rate. By tracking the pressure profiles with a sufficiently fast sampling rate, as provided by the technology, the pressure profiles can be further decomposed and / or analyzed into relative pulmonary tidal volume, cardiac output, relative cardiac output, and absolute cardiac output.

[0040] Thus, aspects of the disclosed technology relate to the fidelity and resolution of a pressure signal produced in response to changes in pressure within the bladder, such changes reflecting the pressure profile within the peritoneal cavity, which pressure profile includes cumulative input from the aforementioned physiological sources. Aspects of the technology further relate to the fidelity and resolution of the conversion of the pressure signal into a highly resolvable electrical signal. Aspects of the technology further relate to processing the entire electrical signal profile, which is a proxy for the pressure profile within the peritoneal cavity, into component profiles that can be assigned to physiological sources.

[0041] The sensitivity of an inflated balloon as a pressure sensor is, in part, a function of the pressure differential across the balloon membrane as a baseline condition. The balloon is most sensitive to pressure when the baseline pressure differential is near zero. As the baseline pressure differential increases, the sensitivity of the pressure-sensitive balloon decreases. Thus, the disclosed technology provides a self-priming method that maintains the balloon in an inflated state but with minimal pressure differential.

[0042] To effectively capture a physiological pressure profile, the profile must be sampled at a rate sufficient to resolve the inherent frequency of change in the profile. This consideration is informed by the Nyquist-Shannon sampling theorem, which states that resolving events occurring at a frequency of B cycles / second requires a sampling frequency of at least 2 B samples / second. For example, when applied to a physiological pressure cycle, a heart rate of 70 beats / minute requires a sampling rate of at least 140 samples / minute to effectively capture the cycle. This relationship is the basis for aspects of the disclosed technology that specify the sampling rates specifically required to capture physiological pressure cycles, such as relative pulmonary tidal volume, cardiac output, relative cardiac output, and absolute cardiac output.

[0043] Embodiments of the present technology include pressure interfaces, such as may be represented by balloons with either compliant or non-compliant membranes.

[0044] Expandable pressure-sensing balloons according to embodiments of the present technology may assume one or more of at least two basic forms: compliant or non-compliant. In compliant balloon types, which can generally be likened to traditional party balloons, the pressure-sensitive balloon is formed from or includes a compliant membrane. Thus, the membrane's surface area expands or contracts as a function of balloon inflation. The membrane's compliance determines the various functions of the balloon as a whole at different levels of inflation. Upon expansion, the balloon, if unconstrained, maintains a substantially constant or preferred shape or configuration, as determined by the mandrel on which the balloon is formed. As the balloon expands from its minimum to its maximum volume, the balloon's membrane maintains a state of tension. Within the compliance of the compliant membrane, an increase in pressure during inflation results in an expansion of the volume. While a balloon may be considered partially conforming in that its shape corresponds to spatial constraints that may be encountered during expansion or inflation, the balloon has a preferred or native shape, and such shape preference prevents the level of conformance exhibited by shape-conforming or non-conforming balloons.

[0045] In a non-compliant balloon, the expandable pressure-sensing balloon is formed from or includes a non-elastic or substantially non-elastic membrane. Therefore, the membrane's surface area does not expand or contract depending on the level of inflation / pressurization of the balloon. A non-compliant pressure-sensing balloon is generally likened to a conventional Mylar® balloon. The lack of membrane compliance determines the different characteristics of the balloon as a whole at different levels of inflation. As the balloon expands from its minimum volume to a level approaching its maximum volume, the balloon membrane is pliable and has some sagging. Inflation of a non-compliant balloon occurs by smoothing wrinkles and folds in the membrane outward. Contraction or compression of a non-compliant balloon generally occurs by inward wrinkles and folds. When a non-compliant balloon is fully inflated (or substantially inflated) without entering a confined space, it assumes a preferred or natural shape determined by the shape of the balloon membrane or fabric. However, in a partially inflated state, the balloon as a whole is very flexible and malleable, generally adopting the shape dictated by the confined space.

[0046] Expandable pressure-sensing balloons according to embodiments of the technology may also include features of both the two basic forms: compliant and non-compliant. In these embodiments, the membrane may include compliant and non-compliant regions. This hybrid type of balloon generally operates in a manner that draws on the operational aspects of both compliant and non-compliant balloons, as described above. Furthermore, compliant balloons may be formed with membranes that are not of uniform composition or thickness. In such embodiments, regions of different thickness or composition can have varying degrees of compliance, thus affecting the behavior of these regions during balloon expansion. In still other embodiments, the membrane's compliance has a bias or polarity that tends to allow compliance in one or more directions and tend to prohibit compliance in one or more other directions.

[0047] Expandable pressure-sensing balloons according to embodiments of the technology may also include features of both the two basic forms: compliant and non-compliant. In these embodiments, the membrane may include compliant and non-compliant regions. This hybrid type of balloon generally operates in a manner that draws on the operational aspects of both compliant and non-compliant balloons, as described above. Furthermore, compliant balloons may be formed with membranes that are not of uniform composition or thickness. In such embodiments, regions of different thickness or composition can have varying degrees of compliance, thus affecting the behavior of these regions during balloon expansion. In still other embodiments, the membrane's compliance has a bias or polarity that tends to allow compliance in one or more directions and tend to prohibit compliance in one or more other directions.

[0048] These data demonstrate the suitability of using embodiments of the pressure transduction system in small-diameter pediatric catheters, down to sizes as small as 4F. Even in this embodiment, the tip of the catheter can have a lower profile than the rest of the catheter to allow for a consistently small diameter even with the addition of a pressure-sensing balloon. Thus, the catheters of the present invention are uniquely suited for pediatric indications, where better, less invasive monitoring methods are desperately needed. In another embodiment, the retention balloon itself can be used as a pressure balloon to minimize the number of lumens required. In one embodiment, the retention balloon is used fully inflated and only to track macro trends in IAP. In another embodiment, the retention balloon is slightly inflated to increase the balloon's sensitivity to small changes in pressure. This embodiment allows for more precise measurement of microparameters, such as heart rate, relative stroke volume, relative cardiac output, respiratory rate, and relative tidal volume. Additionally, smaller pressure lumens free up space in larger catheters for other technologies, such as sensors.

[0049] In sensing Foley catheter embodiments in which a retention balloon is used as a pressure balloon, the pressure measured within the retention balloon is offset by the pressure required to inflate the balloon sufficiently to function as a retention balloon. As a result, the inflation pressure, and possibly the pressure resulting from the retention balloon in contact with the inner surface of the bladder, must be subtracted from the pressure measurement. In this way, small pressure changes can be tracked similarly to those measured with a separate pressure balloon. The inflation pressure offset can be determined by measuring the pressure within the retention balloon when initially inserted into the patient, by measuring the inflation pressure of the retention balloon outside the patient, or by other means. The retention balloon may be filled with fluid, air, or other suitable gas.

[0050] Embodiments of the disclosed technology may include embodiments in which the pressure sensor is a mechanical pressure sensor, such as one that uses fiber optic, strain gauge, magnetic, resonant, and / or other suitable technology.

[0051] 2 shows an example of respiratory rate sensing data from a subject provided by an embodiment of a sensing Foley catheter system. During this test, the subject performs the following respiratory sequence: (1) exhale at the end of expiration, (2) Valsalva, (3) hyperventilation, (4) Valsalva, and (5) exhale at the end of inspiration.

[0052] Figure 3 shows a detailed portion of a normal respiratory cycle for a respiratory profile similar to that shown in Figure 2. The pressure curve clearly shows the respiratory peaks, allowing the peaks of respiratory rate and heart rate to be determined, and therefore the heart rate.

[0053] 4 shows an example of heart rate and relative cardiac output sensed data from a subject, as well as a simultaneous, independently measured EKG trace, provided by an embodiment of a sensing Foley catheter system. The graph clearly shows that the heart rate peaks measured by the sensing Foley catheter are consistent with the heart rate.

[0054] FIG. 5 shows data relating to relative cardiac output sensing during human leg-raising exercise, where cardiac output increases as evidenced by increased amplitude of heartbeat.

[0055] Figures 6 and 7 are from a study conducted using Yorkshire pigs under an IACUC-approved protocol. Figure 6 shows example peritoneal sensing data, focusing on respiratory rate, from a pig provided by an embodiment of the sensing Foley catheter system. Figure 7 shows an example of a pig study demonstrating the ability of an embodiment of the sensing Foley catheter system to detect intra-abdominal hypertension. In this study, the peritoneal cavity was accessed with a 5 mm tenamer trocar. The trocar was then attached to a 5 L bag of lactated Ringer's solution via a peristaltic pump, and the solution was infused at a rate of approximately 1 L per minute. After a pressure of approximately 20 mmHg was achieved, fluid flow was discontinued, and thereafter there was no net fluid flow into or out of the cavity.

[0056] FIG. 8 shows intra-abdominal pressure, respiratory wave pressure, and cardiac pressure arranged generally as a two-dimensional plot of pressure (mmHg on a logarithmic scale) versus frequency (Hz). It can be seen that there is an inverse relationship between pressure and frequency, and when arranged in this manner, various physiological pressure-related parameters occupy different sectors. It is the clarity of both these pressure and / or frequency profiles that allows embodiments of the methods disclosed herein to decompose a single overall temporal pressure profile into distinct sub-profiles depending on their physiological origin. Intra-abdominal pressure measurements can be resolved in a frequency range of approximately 0 Hz to approximately 0.5 Hz. Respiratory pressure measurements can be resolved in a frequency range of approximately 0.25 Hz to approximately 0.75 Hz. Cardiac pressure measurements can be resolved in a frequency range of approximately 0.75 Hz to approximately 3.0 Hz. Intra-abdominal pressure measurements can be resolved in an amplitude range of approximately 5 mmHg to approximately 30 mmHg. Respiratory pressure measurements can be resolved in an amplitude range of approximately 0.5 mmHg to approximately 5 mmHg. Cardiac pressure measurements may be resolved over an amplitude range of approximately 0 mmHg to approximately 0.5 mmHg. The sampling frequency (the frequency at which pressure measurements are taken) is preferably approximately twice the resolution frequency. For example, the sampling frequency may be approximately 0 Hz-1 Hz for intraperitoneal pressure measurements, 0.5 Hz-1.5 Hz for respiratory pressure measurements, and 1.5 Hz-6 Hz for cardiac pressure measurements.

[0057] 9 provides a flow diagram of an embodiment of a method for monitoring pressure, which dynamically develops as waves of varying frequency and amplitude within the abdominal cavity as detected from within the bladder. Through the mechanism of a pressure interface, a high-fidelity pressure profile is generated and transmitted proximally through a fluid column. More proximally, a pressure transducer converts the high-fidelity pressure waves into a high-fidelity electrical signal that provides information about the pressure frequency and amplitude. The generated high-fidelity electrical signal is processed by a controller to generate data subsets that reflect components within the overall pressure profile attributable to specific physiological sources, such as abdominal pressure, respiratory rate, heart rate, relative cardiac output, and patient movement or activity.

[0058] Sensing Foley Catheter System

[0059] 10A shows an embodiment of a sensing Foley catheter used with an embodiment of an airlock clearing mechanism and a fluid collection and analysis system. Both urine output and pressure measurements benefit from the elimination or reduction of airlocks in the urine output line.

[0060] The sensing Foley catheter 1000 is similar to the sensing Foley catheter shown in FIG. 1. The sensing Foley catheter is shown in use in a bladder 1014. Several ports on the proximal end of the catheter shown in FIG. 1 are shown in the embodiment shown in FIG. 10A. A urinary drainage tube 1001 is also shown here. The urinary drainage tube can be combined with the sensing Foley catheter or can be a separate component. The urinary drainage tube 1001 and / or the sensing Foley catheter can also include a vent barb (or barbs) 1016, or the vent barb can be a separate component. An airlock cleaning mechanism and fluid collection and analysis system 1002 is also shown here and is in fluid communication with the urinary drainage tube 1001, which is in fluid communication with the sensing Foley catheter 1000. The airlock cleaning mechanism and fluid collection and analysis system includes a base / controller 1018, a fluid collection bag 1020, and a reservoir or cassette 1022. The combination of the sensing Foley catheter 1000, urinary drainage tubing 1001, and airlock clearing mechanism and fluid collection and analysis system 1002 is also referred to herein as a sensing Foley catheter system. The sensing Foley catheter, urinary drainage line, and reservoir / cassette are disposable and can be sold as a unit. This disposable assembly is shown in FIG. 10D and includes the sensing Foley catheter 1000, urinary drainage tubing 1001 (including vent barbs), and reservoir / cassette 1022.

[0061] The vent barb 1016 can include one or more vent holes 1006 and a urine sampling port 1004. In this embodiment, the vent hole 1006 is preferably made from a membrane that allows gas permeation but not liquid, such as a hydrophobic membrane. One example of such an exemplary vent is a PTFE (polytetrafluoroethylene), ePTFE (expanded PTFE), or Versapor® (from Pall Corporation, Port Washington, NY) membrane, although other materials may be used. The vent tube allows air to enter the system when negative pressure is applied to the drainage tube and to exit the system when positive pressure is created by an airlock in the drainage line. Such a mechanism prevents aspiration trauma, for example, at the bladder wall. The vent hole 1006 may incorporate a one-way valve that prevents air from leaving or entering the drainage line. In a preferred embodiment, a one-way valve is used to prevent air from exiting the drainage line, but allow air to enter the drainage line through the vent 1006. In this way, the valve also prevents urine from contacting the vent 1006.

[0062] The urinary drainage tube 1001 may include several lumens, including a pressure lumen 1010, a temperature lumen 1008, and a urinary lumen 1012. The pressure lumen 1010 is in fluid communication with a pressure sensing balloon 108 and a pressure transducer interface 1026 in the controller 1018. A temperature sensor (not shown) is located on the Foley catheter sensor, and a temperature connector 1024 is located on the controller. The urinary lumen 1012 is in fluid communication with one or more openings 106 and a urinary reservoir or cassette 1022.

[0063] The disposable measurement reservoir, collection reservoir, chamber, or cassette component 1022 is designed to fit into the cassette mount, base, or controller 1018 and interface with the controller components. The controller-cassette interface (behind the cassette pump interface 1148) connects to the pump 1134 and the cassette pump interface 1148 on the disposable cassette component. The pump is designed to generate a vacuum inside the cassette component, which is delivered to the urine drainage lumen of the drainage line. Preferably, the collection reservoir / cassette is rigid to maintain a constant volume as the pump applies negative pressure. The level of applied negative pressure can be monitored by a pressure sensor. During airlock clearance, the pressure follows a characteristic curve, as shown in Figure 59. As suction is applied, the pressure decreases, eventually reaching an inflection point as the urine meniscus passes the lowest point in the drainage tube. At this point, less suction is needed to continue clearing the airlock, so the pump power can be reduced to minimize the amount of suction delivered to the bladder once the airlock is fully cleared. For example, larger vessels without this pressure sensing capability transmit substantial negative pressure to the bladder after the airlock is released, before the bladder has time to equilibrate with the atmosphere. The controller pressure interface (behind the cassette pressure interface 1150) connects a pressure measurement device, such as a pressure transducer, to the cassette pressure interface 1150. The pressure measurement device is designed to measure the volume of urine or other liquid based on the pressure applied to the pressure measurement device, such as the pressure transducer. The ultrasound transducer interface 1130 also provides urine volume measurement. Ultrasound measurement can be used in conjunction with pressure measurement or to determine the volumetric output of urine or other liquid. An active pinch valve 1132 is designed to connect to the cassette's outflow tubing. The pinch valve controls emptying of the cassette reservoir and is controlled by the controller to release urine / fluid when the urine output reaches a specific volume within the cassette, as determined by pressure and / or ultrasound measurement.The amount of urine in the cassette is measured, and when a certain amount is reached, the urine is drained into the urinary drainage bag 1020 via the pinch valve. For example, the cassette is emptied when the amount of urine in the cassette reaches approximately 50 mL. Alternatively, the cassette can be emptied when the amount of urine in the cassette reaches approximately 40 mL. Alternatively, the cassette can be emptied when the amount of urine in the cassette reaches approximately 30 mL. Alternatively, the cassette can be emptied when the amount of urine in the cassette reaches approximately 20 mL. Alternatively, the cassette can be emptied when the amount of urine in the cassette reaches approximately 10 mL. In this way, urine output can be accurately measured over time.

[0064] Emptying of the cassette can be enhanced or accelerated by pressurizing the cassette during the emptying process.

[0065] Alternatively, the controller may utilize a set time between emptying of the cassette and measure the volume of urine in the cassette immediately prior to emptying. Alternatively, the controller may empty the cassette when a vent occurs, such as the removal of an airlock triggered by activation of a pump. For example, the controller may set up a periodic airlock clearance cycle after which the volume of urine in the cassette is measured and the cassette is then emptied.

[0066] For example, the controller can control the pinch valve to empty the reservoir / cassette when the urine volume reaches approximately 50 mL. Alternatively, the controller can control the pinch valve to empty the reservoir / cassette hourly after measuring the urine volume in the cassette. Alternatively, the controller can control the pinch valve to empty the reservoir / cassette during or after a urine drainage vent, such as running a pump. Alternatively, the controller can control the pinch valve to empty the reservoir / cassette using a combination of these triggers.

[0067] Other technologies may be used in addition to or instead of pressure and / or ultrasound to measure urine volume, including pressure-based, resistive-based, capacitive-based, ultrasonic-based, or optical-based technologies. Multiple technologies may be used to compare measurements with each other to improve the accuracy of the volume measurement. Multiple volume measurements made by one or more technologies may be used for redundancy, backup, or in combination with each other to obtain a more accurate urine volume measurement.

[0068] The bed hook 1116 is for hooking the controller to a bed or other device if desired. It can also be used to hook the controller to a portable device for patient transport. The collection bag hook / hole 1102 is for attaching a drainage bag where the urine / fluid ultimately collects after it passes through the pinch valve. The collection bag hook 1102 can be designed to provide a strain measurement so that the weight of the fluid in the bag can be determined, thus providing another method of determining the volume of the fluid in the bag. For example, a piezoelectric transducer may be used. The controller can also use a specific gravity determination to determine a useful volume measurement based on weight and specific gravity.

[0069] Screen 1110 is for displaying information including current urine / fluid volume status, system status, etc. Screen 1110 is also a touchscreen and can receive input including settings, screen display changes, menu changes, etc. Pressure port 1026 connects to bladder pressure line 1010 and, if used, measures bladder pressure using a sensing Foley catheter. Alternatively, the pressure port may be located in the cassette mount below cassette 1022 or elsewhere on the controller / base. Temperature port 1024 connects to a thermistor / temperature sensor that measures body temperature via a sensing Foley catheter via lumen 1008 or other means. Temperature output port 1122 is for transmitting temperature measurements to an external device and / or monitor. Adapter port 1124 is for adapting the controller to other devices, such as in the case of an RFID adapter. This can be used to activate additional / advanced features such as measuring IAP, respiratory rate, heart rate, cardiac output, or other parameters that can be measured with a sensing Foley catheter. This allows additional parameters to be enabled and paid for by the hospital only when that information is needed. Activation of advanced features can also be controlled, for example, by the use of different disposable components. Alternatively, advanced features can be enabled as part of the disposable features or through separately purchased software upgrades. Software upgrades are provided wirelessly, via USB dongle, micro-SD card, EPROM card, or other suitable technology. Individual and / or aggregated patient data may also be stored by the controller. Patient data may be stored in memory, USB, micro-SD card, EPROM card, hard drive, etc. Patient data may be transferred wirelessly or via a wired connection to another storage device, such as a server on the Internet or an intranet. Patient data may be anonymized. Patient data, such as a patient ID, is stored in the RFID adapter so that data unique to a particular patient is recognized by the controller and associated with the disposable components used by that patient.

[0070] A power LED / indicator 1114 indicates whether the power is on or off. An error LED / indicator 1112 is an indicator when an error has occurred within the system. Details of the error can be displayed on the screen 1110, but the indicator 1112 alerts the user that an error exists. The indicator may also incorporate an audible or other warning.

[0071] Port 1108 is used for downloading, uploading, software upgrades, connecting to other devices, such as integration with EMR (Electronic Medical Record) systems. Port 1108 is a USB port or other suitable port. SD port 1106 is for downloading data. Power port 1104 is for connecting the controller to a wall or other power source to power the controller.

[0072] The urine / fluid drainage bag 1020 includes one-way valves 1136 connected to the overflow tube 1138 and outflow tubing 1140, which prevent urine / fluid from exiting the drainage bag once collected. These valves prevent air from entering the collection container 1022 when the pump 1134 is drawing a vacuum, ensuring that the vacuum acts on the drainage tubing and not the bag. In a preferred embodiment, a single valve is used for both the overflow and outflow tubes. Mounting hooks / holes 1102 allow the drainage bag 1020 to be removably attached to the controller 1018. The vent 1142 is a hydrophobic or other vent that allows air or gas to exit the drainage bag but not fluid. This prevents excess air, and potentially pressure, from building up within the bag, thus allowing for efficient filling of the drainage bag. Graduation markings 1144 provide a somewhat coarse measurement of the amount of fluid in the bag as it collects. An outflow valve 1146 can be used to empty the fluid / urine bag. Preferably, the valve can be easily operated by one person. The collection bag hook 1102, designed as a strain measuring element, can also sound an alarm when the bag reaches full capacity and needs to be emptied. An alarm can also be sounded if unnecessary excessive force is applied to the bag, for example if the bag is pulled or gets caught on an obstacle during patient transfer.

[0073] The patient's temperature is measured using a thermistor / temperature sensor inside the patient's body. This temperature is passed through the controller and may be displayed on a third-party device. Figure 10B shows how a parallel potentiometer can be used to reduce errors in the temperature measurement before it is transferred to an external display or device.

[0074] The drainage bag may be made of clear vinyl or other suitable material. The one-way valve may be made of vinyl or other suitable material. The hydrophobic vent may be made of ePTFE, Versapor, or other suitable material. The outflow valve may be made of PVC, PC, or other suitable material.

[0075] Pressure measurements from a sensing Foley catheter can be used to activate a pump and therefore empty the drainage tube. For example, when the pressure sensed in the bladder exceeds a preset number, the pump can be activated to move urine more quickly through the drainage tube.

[0076] The controller / base and / or reservoir / cassette may include an accelerometer or other sensor to determine when the controller / cassette is level and when it is not. If the controller / cassette is not level, an alarm may sound. Alternatively, urine volume measurements may be adjusted to account for different angles within the system.

[0077] The bottom of the urine reservoir in the cassette has rounded edges or is otherwise configured so that urine empties completely from the cassette when the pinch valve is opened.

[0078] FIG. 10C is a detailed diagram of the airlock clearing mechanism and fluid collection and analysis system 1002. Screen 1110 displays a user interface including patient parameters and a touchscreen or other control function. Heart rate area 1152 indicates the patient's heart rate, as determined by the controller based on measurements of intravesical pressure detected by a sensing Foley catheter. Respiration rate area 1154 indicates the patient's respiration rate, as determined by the controller based on measurements of intravesical pressure detected by sensing the Foley catheter. Core temperature area 1156 indicates the patient's core temperature, as detected by a temperature sensor in the Foley catheter, or the like. Urine output area 1158 indicates the patient's current and / or average urine output, as determined by the controller based on urine volume measurements measured by a pressure measurement device connected to pressure interface 1150 and / or ultrasound transducer interface 1130. Sepsis index area 1160 indicates the patient's likelihood of sepsis, as determined by the controller based on one or more collected and / or calculated patient parameters. For example, factors such as body temperature, abnormal heart rate, abnormal respiratory rate, and / or urine output can be considered when determining the risk of sepsis. Trends in these parameters can also be used to assess risk. For example, a decrease in urine output, an increase in heart rate, and an increase or decrease in core body temperature may be indicative of sepsis.

[0079] Other risk assessments may be determined by the controller and displayed in addition to or instead of the Sepsis Index. These include risk assessments for acute kidney injury, urinary tract infection, intra-abdominal hypertension, abdominal compartment syndrome, infection risk, sepsis, and ARDS (acute respiratory distress syndrome). For example, sample risk algorithms for acute kidney injury and urinary tract infection are shown in Figure 58A. Sample risk algorithms for acute kidney injury, sepsis, and acute respiratory distress syndrome are shown in Figure 58B. Measured urine parameters may include conductance, specific gravity, urine output, presence or absence of infection, bacteria, white blood cells, oxygen tension, etc.

[0080] Graphical indicators 1162 show historical data for these areas. For example, a user may be able to touch the screen to toggle the graphical display to show the patient's history, such as urine output, temperature, heart rate, respiratory rate, sepsis index, risk of acute kidney injury, urinary tract infection, intra-abdominal hypertension, abdominal compartment syndrome, infection risk, or other relevant parameters. The historical time frame may be all time, daily, hourly, or a user-configured period. Any risk factors that are out of range and therefore at high risk may be automatically displayed here or elsewhere on the display. Alerts and / or ranges are user-configurable and can include absolute values ​​or trends over time. For example, if core temperature rises by more than 2 degrees over a specific time frame, a visual or audio warning may be displayed.

[0081] FIG. 11A shows an embodiment of a sensing Foley catheter system (including an airlock clearing mechanism, fluid drainage, collection, and analysis system / controller) similar to that shown in FIG. 10A , in which a vent 1180 is located in the controller 1018 or reservoir / cassette 1022. In this embodiment, the vent 1180 is in fluid communication with the urinary drainage lumen 1012 via a vent 1184, which is fluidly connected to the ureteral lumen 1012 at the vent 1184. In this embodiment, the barb design is simplified, and the drainage tube simply has an additional lumen compared to the embodiment shown in FIG. 10A . The vent can be located anywhere within the system, and the fluid interface with the ureteral lumen can also be located anywhere within the system.

[0082] FIG. 11B shows an embodiment of a sensing Foley catheter system similar to that shown in FIG. 11A. In this embodiment, a gas-permeable vent / filter is incorporated into the cassette 1022 and / or controller 1018. A vent lumen can pass along the drainage tubing 1012 from a barb 1182 into a vent tube 1184. The vent lumen may terminate externally to the cassette and / or controller, or, as shown here, pass through the cassette and possibly the controller and incorporate a gas-permeable vent / filter 1180. FIG. 11B also shows a valve 1186. The valve may be a one-way valve that allows the flow of fluid (e.g., atmospheric air) through the vent lumen, through the barb, into the drainage tubing, or elsewhere along the drainage tubing or Foley catheter, or into the base / controller 1018. The valve prevents liquids, such as urine or air, from flowing through the vent tube and potentially reaching the filter. The valve may be passive as shown here, or actively controlled by a controller. The valve may be anywhere within or along the vent lumen, such as within the barb, somewhere along the vent tube, within the cassette, within the controller, or external to the controller, e.g., on the non-patient side of the controller.

[0083] In some embodiments, the valve is actively controlled via the controller by controlling the negative pressure within the drainage tube. The valve can be opened by the controller drawing negative pressure within the drainage lumen of the drainage tube, and closed by the controller reducing the vacuum applied to the drainage tube (i.e., reducing the negative pressure, applying zero pressure, or applying a slight positive pressure to the drainage lumen). Because the drainage lumen of the catheter and drainage tube is in fluid communication with the lumen of the vent tube, negative pressure applied to the drainage tube is also applied to the lumen of the vent tube, opening the valve if the pressure difference across the valve exceeds the valve's cracking pressure. Reducing the vacuum applied to the drainage lumen closes the valve again, thus reducing the pressure difference across the valve to a pressure below the valve's cracking pressure. In this way, the controller can actively control the opening and closing of the valve in the vent tube, even if the valve itself is a passive valve.

[0084] In some embodiments, the controller actively opening the valve may do so periodically, for example, on a regular schedule. This is shown graphically in FIG. 11F. For example, the controller may open the valve at least every 30 minutes (represented by T1), hold it open for at least 15 seconds (represented by T2), and then close it for another 30 minutes before the cycle begins again. The difference between the vacuum applied to open the valve and the vacuum applied to keep the valve closed is represented by DIFF in the diagram. DIFF is greater than the valve's cracking pressure differential. Alternatively, T1 is at least 60 minutes. Alternatively, T1 is at least 20 minutes. Alternatively, T1 is at least 10 minutes. Alternatively, T1 is at least 5 minutes. Alternatively, T2 is at least 5 seconds. Alternatively, T2 is at least 10 seconds. Alternatively, T2 is at least 20 seconds. Alternatively, T2 is at least 30 seconds.

[0085] FIG. 11F shows the valve closing pressure at a negative pressure, but the valve closing pressure can be zero or positive.

[0086] Alternatively, the cycle length may be variable, with T1 and / or T2 depending on the urine output rate. Alternatively, the cycle may be based on a system that detects airlocks in the drainage tube. This can be done by measuring the pressure in the system, for example, the vacuum pressure in the drainage tube or the pressure at the barb.

[0087] In some embodiments, the valve 1186 can be in place without the filter 1180. In some embodiments, the filter 1180 can be between the drainage lumen and the valve 1186.

[0088] In some embodiments, the vent tube 1184 is integral with the drainage tube 1012 along all or part of the length of the drainage tube.

[0089] The valve may be a duckbill valve, umbrella valve, ball valve, dome valve, Belleville valve, cross slit valve, x-fragment valve, or other valve suitable for medical applications. The cracking pressure of the valve can be very low or higher, but is usually between zero and the amount of negative pressure drawn by a vacuum pump.

[0090] FIG. 11C shows an embodiment of a sensing Foley catheter system similar to that shown in FIG. 11B. In this embodiment, the vent tube includes a portion of the lumen with a smaller diameter between the barb and the valve. The smaller inner diameter tubing between the barb and the valve creates a column of air between the valve and the barb, which generally prevents urine from entering the vent tube when the vent tube valve is closed. When the vent tube valve is open, fluid flow generally is in the reverse direction (i.e., into the drainage lumen), preventing urine from entering the vent tube.

[0091] FIG. 11D shows an example of a vent tube with different diameter sections. The first section 1188 is the section closest to the patient and has an inner ID of ID1 and a length of L1. In this embodiment, the valve 1186 allows fluid to flow generally only from right to left, as indicated by the dashed arrow. The second section 1190 is further away from the patient and has an inner ID of ID2 and a length of L2. In some embodiments, L1 is less than L2 and ID1 is less than ID2. In some embodiments, ID1 is less than ID2, but the lengths may vary or be the same. L1 + L2 is approximately the same length as the drainage tube.

[0092] In some embodiments, ID1 may be approximately 1.8-2.0 mm. In some embodiments, ID1 may be approximately 1.6-1.8 mm. In some embodiments, ID1 may be approximately 1.4-1.6 mm. In some embodiments, ID1 may be approximately 1.2-1.4 mm. In some embodiments, ID1 may be approximately 1.0-1.2 mm. In some embodiments, ID1 may be approximately 0.8-1.0 mm. In some embodiments, ID1 may be approximately 0.5-0.8 mm. In some embodiments, ID1 may be approximately 0.2-5 mm. In some embodiments, ID1 may be less than approximately 1 mm. In some embodiments, ID1 may be less than approximately 2 mm. In some embodiments, ID1 may be less than approximately 3 mm. In some embodiments, ID1 may be less than approximately 4 mm. In some embodiments, ID1 may be less than approximately 2 mm. Preferably, ID1 is small enough to retain the siphon over all or part of its length.

[0093] In some embodiments, ID2 may be approximately 1.8-2.0 mm. In some embodiments, ID2 may be approximately 1.6-1.8 mm. In some embodiments, ID2 may be approximately 1.4-1.6 mm. In some embodiments, ID2 may be approximately 1.2-1.4 mm. In some embodiments, ID2 may be approximately 1.0-1.2 mm. In some embodiments, ID2 may be approximately 0.8-1.0 mm. In some embodiments, ID2 may be approximately 0.5-0.8 mm. In some embodiments, ID2 may be approximately 0.2-5 mm. In some embodiments, ID2 may be less than approximately 4 mm. In some embodiments, ID2 may be less than approximately 5 mm. In some embodiments, ID2 may be less than approximately 6 mm. In some embodiments, ID2 may be greater than approximately 2 mm. In some embodiments, ID2 may be less than approximately 6 mm. In some embodiments, ID2 may be greater than approximately 2 mm. In some embodiments, ID2 may be greater than approximately 5 mm. In some embodiments, ID2 may be greater than approximately 6 mm.

[0094] In some embodiments, L1 may be less than about 5 cm. In some embodiments, L1 may be less than about 10 cm. In some embodiments, L1 may be about 5-10 cm. In some embodiments, L1 may be about 10-20 cm. In some embodiments, L1 may be about 20-30 cm. In some embodiments, L1 may be about 30-50 cm. In some embodiments, L1 may be greater than about 50 cm. In some embodiments, L1 may be greater than about 1 cm. In some embodiments, L1 may be greater than about 2 cm. In some embodiments, L1 may be greater than about 5 cm. In some embodiments, L1 may be greater than about 10 cm.

[0095] In some embodiments, L2 can be about 50 to 150 cm.

[0096] In some embodiments, ID1 and ID2 may be the same.

[0097] FIG. 11E shows an embodiment of the catheter system in which the vent lumen 1184 is in direct fluid communication with the fluid collection bag 1020. In this embodiment, a controller including sensing functionality may or may not be present. In this embodiment, an airlock is avoided by a vent lumen that vents the urinary drainage lumen 1012 using a vent hole 1142 in the fluid collection bag. The vent hole may additionally or alternatively be located anywhere along the vent lumen. The vent lumen may run part or all of the length of the drainage lumen. The urinary drainage lumen fluidly connects to the drainage bag at a connection point 1192, which may include a valve 1136. The vent lumen connects to the drainage bag at a connection point 1194. The fluid collection bag 1020 in this, and potentially other, embodiments may include a rigid or semi-rigid portion 1196 to ensure that the fluid collection bag does not collapse around the connection point 1194. This embodiment may or may not include a valve 1186. The vent tube 1184 may be incorporated into the drainage tubing system or may be an add-on component that connects at a connection point 1194 between the barb on the Foley catheter and the drainage bag.

[0098] FIG. 12A shows an embodiment of a sensing Foley catheter system similar to that shown in FIG. 10A , in contrast to the system shown in FIG. 10A , in which a pressure balloon is not utilized. Instead, pressure is measured within the bladder via the ureteral lumen (or other lumen) of the sensing Foley catheter. In this embodiment, the pressure lumen 1202 is connected to a vent 1204 or elsewhere in the system external to the patient and is in fluid communication, at least periodically, with the drainage / ureteral lumen of the catheter. In this embodiment, the sensing Foley catheter system may be used with any standard Foley catheter. Note that any embodiment of the sensing Foley catheter system can be used with a standard Foley catheter. The system shown in FIG. 12 may be used with a standard Foley catheter without the pressure lumen 1202 if intravesical pressure measurement is not desired.

[0099] 12B shows an embodiment of a sensing Foley catheter system that does not include measurement of IAP or temperature, yet still provides airlock prevention.

[0100] Figure 13 shows an embodiment of a sensing Foley catheter system similar to that shown in Figure 12. In this embodiment, a valve 1302 can be utilized to periodically close the pressure lumen 1202 to the urinary drainage lumen. The valve can be opened by a controller or manually when a pressure measurement is taken and closed again by a controller or manually when bladder pressure readings are not needed.

[0101] 10A, 10C, 11, and 12 show embodiments of a sensing Foley catheter system that include a vent near the patient end of the drainage tube that allows air to enter the drainage tube in the event of negative pressure created by either a siphon or a pump mechanism within the drainage tube, or both. Without the vent / filter, such negative pressure could lead to suction trauma, such as trauma caused to the mucosal lining of the bladder. Note that these embodiments differ from devices in which the vent allows air to escape but not enter the drainage tube.

[0102] The urinary drainage lumen preferably has an inner diameter of less than about 0.25 inches so that the fluid within the lumen maintains circumferential contact with the lumen, forming a seal and allowing fluid to advance when the pumping mechanism is activated. Multiple drainage lumens may be present to prevent flow blockage in the event of pumping mechanism failure. In these embodiments, the drainage lumens are preferably generally empty, which may require continuous activation of the pumping mechanism. Alternatively, the pumping mechanism can be activated before taking a volume measurement to ensure all fluid has been drained, reducing the power requirements of the device.

[0103] Some embodiments of the sensing Foley catheter system involve detecting pressure spikes in the drainage line while the pressure within the body organ remains constant, and using a pump to create negative pressure through the drainage line until the pressure in the drainage line equals the pressure in the body organ.

[0104] In one embodiment, the vent has a resistance to airflow that is greater than the resistance to fluid flow from the patient, so that any fluid buildup within the patient is purged into the drainage line before air can enter through the vent. For example, in the case of urinary drainage, as long as the resistance to airflow through the vent is greater than the resistance to urine flow through the patient's catheter, a full bladder will drain into the drainage line before air can enter through the vent. However, to minimize aspiration trauma, it is preferable that the vent have as little resistance to airflow as possible while still meeting this requirement.

[0105] In another embodiment, because the vent provides very little resistance to airflow, the bladder is further protected from suction, and the controller-pump keeps urine out of the drainage line at more frequent intervals, such as every 1 minute, 5 minutes, or 10 minutes. Once activated, the pump continues to operate until it detects that no more urine is being discharged, indicating the bladder is completely emptied. Alternatively, the pump may operate for a set period of time, such as about 30 seconds, about 1 minute, about 3 minutes, about 5 minutes, or about 10 minutes. The controller-pump may be inactive between intervals or may generate a "background vacuum" (a negative pressure lower than the airlock clearance pressure) between airlock clearance intervals.

[0106] The pump mechanism used may be any suitable mechanism, including, but not limited to, a peristaltic pump, diaphragm pump, vane pump, impeller pump, centrifugal pump, or other suitable pump. The pump may be powered from a wall outlet, battery, human power, or other suitable power source. In some embodiments, the vacuum ranges from approximately 0 to -50 mmHg. Alternatively, the negative pressure may be provided by a wall vacuum, which is often present in hospital rooms. The pump mechanism may include a peristaltic pump or suction applied directly to the collection container. The pump may be located on the patient side of the drainage reservoir, or the pump is preferably located on the non-patient side of the drainage reservoir / cassette, with the reservoir between the patient and the pump. To function properly, the pump should be capable of generating a negative pressure equal to the maximum fluid column height in the drainage tubing, which may be half the length of the drainage tubing. For a urinary drainage tube with a maximum length of 60 inches, the maximum negative pressure required would be approximately 30 inches H2O, or 56 mmHg.

[0107] Other techniques can be used to urge urine through the tube and / or system, including pulsatile mechanical, vibroacoustic, thermal, vibratory, pinching, rolling, or electromagnetic stimulation to induce movement of the drainage line and / or fluid therein. In some embodiments, the rolling stimulation includes sequential compression of multiple lumens, such that the lumens are never all compressed simultaneously.

[0108] In another embodiment, the airlock is eliminated by a collapsible drainage tube within a stiffer kink-resistant tube. FIG. 14A shows such an embodiment in an uncollapsed configuration. An inner collapsible drainage tube 1402 is inside an outer kink-resistant tube 1404. FIG. 14B shows an embodiment in which the inner collapsible tube is collapsed. The drainage tube is periodically collapsed, such as by applying positive pressure to the space between the collapsible tube and the kink-resistant tube, or negative pressure to the inside of the collapsible tube. The collapse of the drainage tube then forces urine out of the patient and toward a collection container.

[0109] In another embodiment, the drainage lumen clearing mechanism comprises a tube with an inner diameter of less than approximately 0.25 inches, so that air pockets cannot migrate down the length of the tube. This is made possible by surface tension within the small tube, which prevents fluid movement when one end of the tube is closed to the atmosphere (as in the case of a bladder). Therefore, the drainage tube always remains filled with urine, and because urine is incompressible, an equal volume of urine must exit the drainage tube for each volume of urine produced. In another embodiment, the inner diameter is less than 0.125 inches. In another aspect, the drainage tube acts as a siphon, providing a small, safe amount of vacuum to the bladder. Alternatively, using a small lumen drainage tube allows air to periodically enter the lumen through a vent / valve. Negative pressure created by a pump may facilitate this. Due to the negative pressure created by the pump, urine continues to flow into the collection reservoir, preventing an airlock.

[0110] Additionally, the use of smaller diameter tubing results in less residual urine in the drainage tube compared to conventional techniques. A smaller residual volume is preferred because it allows urine to move more quickly from the patient's bladder to the collection container. This speed of transport is important for measuring more recently produced urine. This is especially important for patients with low urine production rates, as it takes more time for urine to travel from the bladder to the collection container. For example, for a patient producing only 10 mL / hr of urine using standard drainage tubing (approximately 40 mL residual volume), measuring urine in the collection container will delay true urine production by 4 hours. In contrast, with smaller tubing (such as a tubing with approximately 5 mL residual volume), the measurement will only delay true production by 30 minutes. Some embodiments utilizing small diameter lumens, with or without a vent / valve, do not require a pump to provide negative pressure to the drainage line.

[0111] FIG. 15 shows an embodiment of a device well suited for draining a chest tube or other drainage tube that applies a constant negative pressure to a patient. These embodiments may also be suitable for draining urine from the bladder or fluids from other cavities. Any of the features disclosed in connection with chest tube drainage may also be applied to bladder drainage or other body cavity drainage. Fluid is drained from the patient through a drainage lumen 1585 that connects to a collection tube 1582. Drainage is assisted by applying negative pressure to the collection container 1582, for example, by attaching a suction tube 1583 to a hospital wall suction. Suction may also be applied in other ways, such as with a pump as disclosed elsewhere herein. Air enters the drainage lumen 1585 through a valve 1584 that has a cracking pressure equal to the desired negative pressure. Once the correct cracking pressure (e.g., -15 to 0 mmHg, or 10 mmHg) is selected, the pressure on the patient will remain at this pressure as long as the hospital wall suction / pump can generate sufficient suction at the collection container 1582. Preferably, the drainage lumen used to drain the chest tube is as large as possible while maintaining a siphon. Suitable inner diameters include, but are not limited to, about 1 / 4 inch, about 5 / 16 inch, or about 3 / 8 inch.

[0112] FIG. 16 shows another embodiment of a device well suited for draining a chest tube or other drainage tube that applies a constant negative pressure to the patient. Fluid is drained from the patient through a drainage lumen 1688, and negative pressure is applied using a pumping mechanism 1686. A pressure sensor 1687 is located within the drainage tube on the patient side and measures the pressure exerted on the patient. The measurements obtained by the sensor 1687 are sent back to a controller that controls the pumping mechanism 1686, and the pressure produced by the pumping mechanism 1686 is adjusted to maintain the pressure at the sensor 1687 (and the patient) at a desired level. The pressure sensor 1687 can also be located elsewhere in the system. A sensor can also be used to passively monitor the pressure on the patient side of the tube, providing the clinician with information about the level of suction being applied. While FIG. 16 shows the pump on the patient side of the drainage reservoir, the pump could alternatively be located on the opposite side of the drainage reservoir, with the reservoir between the patient and the pump.

[0113] In another embodiment of the invention used for chest tube drainage, the volume of fluid drained is measured to provide the clinician with information about the status of the chest tube drainage. This measurement can be accomplished by any suitable means, particularly those described for measuring urine volume.

[0114] In addition to eliminating airlocks, some of the airlock clearance designs detailed above have been found to effectively remove sediment and blood clots from urinary drainage lines. These issues plague current urinary drainage tubes, especially those with smaller lumen drainage tubes and drainage bags that involve monitoring technology. The present invention advances the state of the art by automating the removal of these drainage-blocking debris and clots. This feature is particularly useful when used in conjunction with pressure sensing, either at the Foley tip balloon or in fluid communication with the bladder. This allows for monitoring of intrabladder pressure and vacuum, allowing for more aggressive pumping based on actual bladder pressure until the clot / blockage is resolved. Without this pressure / vacuum sensing, pumping of fluid within the drainage tube can result in clinical sequelae to the bladder, such as aspiration trauma, due to exposure of the bladder mucosa to excessive vacuum.

[0115] In another embodiment shown in Figure 17, a gas sampling lumen 1790 extends the length of the drainage tube and terminates in a gas-permeable, liquid-impermeable filter 1791 that remains in contact with the urine, with its meniscus 1792 further from the patient than the filter. When oxygen, carbon dioxide, or other gas measurements are desired, air within the gas sampling lumen 1790 is drawn into the base 1789 of the drainage device for analysis. This configuration allows for accurate gas analysis even in device embodiments that allow air to enter the drainage line, such as those shown in Figures 10 through 16.

[0116] As shown in FIG. 18 , the active vent system includes a vent 1802, a drainage line 1804, a collection container 1806, and a pump 1808. The vent side of the drainage line is connected to the patient. In one embodiment, the drained fluid is urine, and a connection is made to a urinary catheter. Fluid flows from the patient through the drainage line and is collected in the collection container. The pump in this embodiment draws a vacuum on the collection container rather than acting directly on the drainage line. The pump applies negative pressure to the collection container to promote drainage, forcing liquid into the drainage line. Preferably, the collection container is rigid to maintain a constant volume when the pump applies negative pressure. The vent on the patient side of the drainage tube is preferably a vent that allows the passage of gas (preferably air) but prevents the passage of liquid. The vent thereby prevents the application of substantial negative pressure to the patient by allowing atmospheric air into the system. Such a mechanism prevents suction trauma, for example, to the bladder wall.

[0117] The pump in this system can be any suitable pump for pumping gases, including, but not limited to, a peristaltic pump, a diaphragm pump, or a centrifugal pump. To function properly, the pump should be able to generate a negative pressure equal to the maximum fluid column height in the drainage tube, which may be half the length of the drainage tube. For a urinary drainage tube with a maximum length of 60 inches, the maximum negative pressure required would be approximately 30 inches H2O, or 56 mmHg.

[0118] As shown in Figure 19, an active vent system for draining bodily fluids may include additional vents. One such vent, vent 1962, may be located on the collection container, allowing air to escape from the collection container. This allows each volume of fluid entering the system to be offset by an equal volume of air exiting the system, preventing pressure buildup as new fluid enters the container. Another such vent, vent 1964, may be located between the collection container and the pump. This vent allows the passage of gases (preferably air) but prevents the passage of liquids to prevent bacteria and viruses from entering or exiting the collection container and drainage tube. Preferably, this vent is sterile-grade, meaning that the air passing through is considered sterile. A vent (not shown here) may or may not be located on the patient side of the drainage line.

[0119] As shown in FIG. 20, pressure offset can be achieved with a single vent in the collection reservoir. In this case, the vent, vent 2072, is between the collection reservoir and the pump as described above, but an additional valve 2074 allows air to escape from the collection reservoir in the presence of positive pressure. This valve allows air to be expelled from the system but not enter it. When the pump is activated, the one-way valve closes and air should be drawn from the collection reservoir, which creates negative pressure on the collection and promotes fluid flow through the drainage line. The vent may or may not be present on the patient side of the drainage line (not shown here).

[0120] Infection detection

[0121] FIG. 21 shows an embodiment of a collection container, chamber, or cassette that can be included in a sensing Foley catheter system for detecting bacteria, blood, and / or other substances in urine using UV / light / Raman spectroscopy. Cassette 2100 includes a container wall 2102, which is preferably rigid. Urine 2106 collects in the cassette. If urine collects too quickly or if there is any obstruction to emptying the cassette, an overflow area 2104 allows excess urine to drain from the cassette. Cassette 2100 can include an optically transparent section 2110, preferably incorporated into the outer wall of the cassette, and a reflector section 2112, preferably located on or incorporated into the inner wall of the cassette. Here, "optically transparent" means that light of the required analytical wavelengths can be transmitted through the optically transparent section. The optically transparent section is preferably made of a material that is transparent to ultraviolet light, such as polymethyl methacrylate, polystyrene, acrylic, or quartz. The wall thickness must be thin enough to allow the appropriate UV wavelengths to pass through the optically transparent section. For example, the optically transparent section may have a thickness of about 0.5 mm to about 0.7 mm. Alternatively, the optically transparent section may have a thickness of about 0.5 mm to about 0.6 mm. Alternatively, the optically transparent section may have a thickness of about 0.6 mm to about 0.7 mm. Alternatively, the optically transparent section may have a thickness of less than about 0.7 mm.

[0122] The UV / light transmitter / receiver 2108 transmits the appropriate wavelength of UV or other light through the optically transparent compartment 2110, the urine in the cassette, and onto a reflector 2112 in the cassette. The UV / light transmitter / receiver may be incorporated into or connected to the controller component of the sensing Foley catheter system. The light reflects back to the UV / light receiver, which transmits the collected data to the controller for signal analysis. Multiple UV / light wavelengths can be analyzed simultaneously or sequentially. Light outside the UV range can be used in addition to light within the UV range. The amount of physical urine between light transmission and reception is preferably maximized for a stronger signal reflecting the concentration of one or more substances in the urine. The transmitter / receiver can be located as shown in FIG. 21 or in other areas of the cassette. The receiver may be in a different location than the transmitter, and a reflector may not be necessary or present. Because the urine in the cassette is emptied frequently, UV / light absorption measurements can be collected over time, and increases and / or decreases in the levels of one or more substances in the urine can be tracked essentially or near real time. This is particularly important for quickly identifying infections, such as urinary tract infections and catheter-associated urinary tract infections (CAUTIs). UV / light detection can also be performed at other locations in the Foley catheter system for sensing, including drainage tubing, separate sampling areas, etc.

[0123] Infection can be identified by analyzing urine for bacteria, red blood cells, plasma, and / or white blood cells using UV / light spectroscopy. Figure 22 shows the various absorption wavelengths of E. coli, red blood cells, and plasma in urine. The presence of plasma / white blood cells and / or bacteria in urine are both indicators of infection. The presence of red blood cells may not be an indicator of infection. Therefore, it is desirable to distinguish between red blood cells and bacteria / plasma / white blood cells in urine. Because the spectroscopic signature of red blood cells is significantly different from either bacteria or plasma / white blood cells at a wavelength of approximately 414 nm, the red blood cell signal can be separated from the bacterial and / or plasma / white blood cell signals, and infection can be identified by analyzing the absorption of light at this wavelength. Because the signatures of plasma and bacteria are different from each other at wavelengths of 260 nm and 280 nm, these wavelengths can be used to distinguish between plasma and bacteria. However, both plasma and bacteria may be present during an infection.

[0124] Other wavelengths and other techniques can also be used to detect various substances in urine or collected / excreted bodily fluids. UV / light absorption can also be used to detect turbidity. Dyes, drugs, or reactive substances can be introduced into the system or coated on the interior of the system, cassette, etc. to react with substances in the urine and aid in the analysis. Any type of sensor can be used to intermittently or continuously detect the substance or quality of the collected urine in real time. For example, a sensor that detects magnesium in urine can be used to diagnose pre-eclampsia or eclampsia. A lactate sensor can be used to test for lactate (or lactate dehydrogenase) in urine. Identifying lactate in urine may be an early indicator of sepsis. Lactate sensors may include enzymatic lactate sensors. See, for example, Weber (Weber J., Kumar A., ​​Kumar A., ​​Bhansali S. Novel lactate and pH biosensor for skin and sweat analysis based on single walled carbon nanotubes. Sens. Actuators, B., Chem. 2006;117:308-313), and / or Mo (Mo, JW, Smart, W. Lactate biosensors for continuous monitoring. Front Biosci. 2004 Sep 1;9:3384-91), both of which are incorporated herein by reference in their entireties.

[0125] Using an appropriate sensor, drugs or drug residues can be detected in collected urine. Other substances or properties of collected urine that may be sensed include color, clarity, odor, specific gravity, osmolality, pH, proteins, glucose, creatinine, nitrites, leukocyte esterase (WBC esterase), ketones, red or white blood cells, casts, crystals, bacteria, yeast cells, parasites, squamous cells, etc.

[0126] CAUTI or infection can be identified and / or reduced by several methods, including analyzing urine using spectroscopy, optical wavelengths, etc., for early detection of contaminants, reducing bladder trauma due to suction, reducing urinary bladder retention, reducing the presence of bacteria or microorganisms through the use of antibacterial coatings or implants such as silver or other materials, improving the accuracy of intravesical pressure measurements by reducing suction within the bladder, and improving the accuracy of urine output measurements by reducing airlocks and suction within the system. A pressure spike caused by suction within the bladder can be defined as a pressure measurement of less than about -20 mmHg. Alternatively, a pressure spike caused by suction within the bladder can be defined as a pressure measurement of between about -10 mmHg and less than about -20 mmHg. Alternatively, a pressure spike caused by suction within the bladder can be defined as a pressure measurement of less than about -10 mmHg.

[0127] CAUTI can also be reduced by using UV light, or any effective wavelength of light or radiation, to reduce bacteria in the urine and / or the system. Urine can be treated using UV light that disinfects the urine within the cassette or elsewhere in the system. For example, UV light may disinfect the urine as it enters the cassette, such as at the inlet valve 10104 as shown in FIG. 101A, or within the cassette, or above the cassette, such as in the drainage tubing above the cassette.

[0128] Figure 23 shows an embodiment of a cassette that includes a baffle or flap 2302. This baffle / flap is intended to prevent urine from wicking up along the interior walls of the cassette, as indicated by the dotted arrow. The baffle prevents urine from wicking past the point of the baffle, allowing the urine to return to the measurement reservoir below.

[0129] Priming

[0130] Aspects of the disclosed technology that are particularly advantageous for achieving high-resolution signals from certain physiological sources (e.g., peritoneal pressure, respiratory rate, heart rate, relative pulmonary tidal volume, cardiac output, relative cardiac output, absolute cardiac stroke volume, etc.) can be monitored in conjunction with adjusting and maintaining a balance of pressure on either side of a pressure interface represented by the membrane of a pressure-sensing balloon. This balance of pressure may be referred to as a pressure differential. In some embodiments, the preferred pressure differential is zero or near zero. In some embodiments, the preferred pressure differential may be a different value. The pressure acting on the outer surface of the balloon (facing the inner surface of the bladder) varies depending on the patient's physiology. The pressure on the inner surface of the balloon (in fluid communication with the fluid column) is subject to degradation due to fluid leakage and imperfect sealing.

[0131] When a sensing Foley catheter is initially inserted, an external pressure is applied to the fluid column against the pressure interface, typically to a first approximation of the pressure applied from within the bladder to the pressure interface. The pressure signal measured at the pressure interface has its maximum amplitude when the pressure difference is near zero. Therefore, the amplitude of the pressure signal can be used to adjust the pressure applied from the fluid interface to the pressure interface. This process of applying the appropriate amount of pressure to the interface is sometimes referred to as priming the fluid column or priming the balloon. As noted above, the pressure on both sides of the pressure interface can change, so the fluid column must be primed or re-primed from time to time. The need for re-priming can be monitored by testing for small changes in pressure to achieve the maximum amplitude of the pressure signal profile. Alternatively, priming can be performed automatically via a controller on a periodic basis.

[0132] Embodiments of the disclosed systems and methods include automatic pressure adjustment by a controller. Thus, the adjustment system can detect the optimal target pressure and volume at which to inflate the balloon by monitoring the sensed pressure signal and adding or removing air or fluid volume as needed. For example, during catheter insertion, a pressure adjustment circuit that adjusts the balloon volume and pressure may inflate the balloon until it detects physiological pressure. Upon sensing that rate, the pressure adjustment controller adds or removes minute amounts of air in a routine or programmed sequence until the sensed wave amplitude is maximized. The control feedback loop between the optimally adjusted pressure (manifested as balloon pressure and volume) and the sensed physiological pressure profile is continually repeated as necessary to ensure high-fidelity measurement of physiological data. In some embodiments, the automatic pressure adjustment may be performed in the apparent background while physiological data is transmitted and displayed; in other embodiments, the system may pause transmission of physiological data during the pressure adjustment sequence.

[0133] An embodiment of the disclosed technology includes a gas delivery system capable of delivering gas via a priming operation, thereby applying pressure to a fluid column proximal to the proximal-facing side of a pressure interface. A gas source, such as compressed air or liquid, is held in a storage tank. Using CO2 as an example, CO2 is controllably released from the storage tank via a pressure regulator that can reduce the pressure within the tank (e.g., approximately 850 psi) to a range of approximately 1 psi to approximately 2 psi. The released gas passes through a filter and a pressure relief valve set at approximately 2.5 psi. The pressure relief valve is a safety feature that prevents gas flow above 2.5 psi in the event of an upstream regulator failure. The CO2 exiting the pressure relief valve then passes through a first solenoid-controlled fill valve into the catheter line, ultimately filling a balloon containing a pressure-sensing interface. When the pressure within the balloon rises to a level of 30 mmHg, the first solenoid-controlled valve closes. A second solenoid-controlled valve distal to the first valve acts as a drainage valve, capable of releasing pressure from the catheter to a target pressure. Alternatively, the drainage valve is activated until a respiratory waveform is detected, after which the balloon is optimally primed and the valve is closed. The drainage valve may be subject to proportional control, operating on voltage or pulse-width modulation (PWM), which slows the drainage rate sufficiently to reach the target pressure and close the valve before overshooting. Alternatively, a peristaltic pump or other air pump may be utilized to fill the balloon with room air.

[0134] FIG. 24 shows a graph illustrating a pressure balloon priming method in some embodiments. Here, a small burst of fluid (approximately 0.3 cc) is added to a pressure-sensing balloon and the pressure inside the balloon is measured. The small burst of fluid is introduced until the measured pressure inside the balloon settles to a stable pressure 2401. This transition is shown at inflection point 2402. Volume bursts are introduced past this point until the measured pressure begins to increase rapidly (e.g., when the slope 2404 of the curve is greater than approximately 2 mmHg / 10 ms). This inflection point is shown at 2406. At this point, the pressure inside the balloon drops to a pressure around or slightly above the stable pressure 2401. This pressure, in some embodiments, represents the prime pressure at which the pressure is measured. This process is also shown in the flowchart of FIG. 27.

[0135] Alternatively, priming the pressure balloon involves pressurizing the pressure balloon well above 0 mmHg, then removing a small amount of air / gas / fluid and monitoring the pressure in the pressure balloon. The pressure in the pressure balloon stabilizes as it approaches the optimal priming pressure. To determine this optimal pressure, a pressure measurement is taken when a small amount of air is removed from the pressure balloon. If the subsequent pressure measurements are essentially the same (within about 2 mmHg of each other), the balloon is at the optimal priming pressure. If the two subsequent measurements are not essentially equal, the pressure balloon is repressurized well above 0 mmHg and the process is repeated. The pressure measurements taken when a small amount of air is removed from the pressure balloon are taken over a period of about 5 to about 15 seconds to compensate for the effects of breathing on the pressure measurements. In some embodiments, the pressure signal may require a short stabilization period after a small amount of air / gas / fluid is removed from the pressure balloon before a pressure measurement is taken.

[0136] The small liquid squirt will be about 0.2 cc to about 0.4 cc. The small liquid squirt can be about 0.1 cc to about 0.5 cc. The small liquid squirt is up to about 0.5 cc. The small liquid squirt is up to about 1.0 cc.

[0137] FIG. 25 shows a graph illustrating a pressure balloon priming method in some embodiments. This method is similar to the method shown in FIG. 24, except that there is no burst as shown in FIG. 24 and the pressure in the pressure-sensing balloon increases more smoothly. A volume of fluid is added to the pressure-sensing balloon and the pressure in the balloon is measured. The balloon pressure is increased until the measured pressure in the balloon settles to a stable pressure 2505. This transition is shown at inflection point 2506. The balloon pressure increases beyond this point until the measured pressure begins to increase rapidly (e.g., when the slope 2510 of the curve is greater than about 2 mmHg / 10 ms). This inflection point is shown at 2508. At this point, the pressure in the balloon drops to a pressure around or slightly above the stable pressure 2505. This pressure represents the optimal, or prime, pressure in some embodiments. This process is also shown in the flowchart of FIG. 28.

[0138] FIG. 26 shows a flowchart of a balloon priming process in certain embodiments of the present invention. Embodiments of the disclosed systems and methods include automatic pressure adjustment by a controller. Thus, the adjustment system can detect optimal target pressure and volume to inflate the balloon by monitoring the sensed pressure signal and adding or removing air volumes as needed. For example, upon catheter insertion, a pressure adjustment circuit that adjusts the balloon volume and pressure inflates the balloon until it detects physiological pressure. Upon sensing this rate, the pressure adjustment controller adds or removes minute amounts of air or fluid (approximately 0.3 cc) in a regular sequence until the sensed wave amplitude is maximized. The control feedback loop between the optimally adjusted pressure (manifested as balloon pressure and volume) and the sensed physiological pressure profile is continually repeated as necessary to ensure high-fidelity measurement of physiological data. In some embodiments, automatic pressure adjustment may be performed in the apparent background while physiological data is transmitted and displayed; in other embodiments, the system may pause transmission of physiological data during the pressure adjustment sequence.

[0139] A trace amount of air or liquid may be about 0.2 cc to about 0.4 cc. A trace amount of air or liquid may be about 0.1 cc to about 0.5 cc. A trace amount of air or liquid may be up to about 0.5 cc. A trace amount of air or liquid may be up to about 1.0 cc.

[0140] In some embodiments, priming of the balloon may be based on system characteristics. The pressure balloon may be inflated one or more times to characterize the system, including the ultrasound transducer, pressure pump, system resistance, pressure balloon, etc. The pressure balloon may be pressurized over a range of pressures to determine the characteristics of the particular system at that time. This information is used to optimize the inflation pressure of the pressure balloon.

[0141] Loop Controller

[0142] Certain patient parameters measured by a sensing Foley catheter system or other means are affected by the treatment of the patient with a medical device.

[0143] The loop controller can be integrated with the controller of the sensing Foley catheter system (either in the same device or a separate device) to interpret patient parameters and control patient therapy.

[0144] For example, IAP can be used to control IV infusion rates. If IAP becomes too high, the infusion rate may be slowed or stopped until the IAP returns to an acceptable range. IAP, combined with relative stroke volume and / or stroke volume variability (variations in the size of the cardiac pulse, such as seen in the bladder during the respiratory cycle), allows for better control of IV fluid or blood product infusion, using IAP as an indicator of excess fluid and relative increased stroke volume, and reduced stroke volume variability as an indicator of the need for additional fluid. Urine output may also be added to the control loop, providing an indication that fluid status has been restored when urine output returns. Heart rate and respiratory rate can be combined to control drug infusion (e.g., type of drug, infusion rate, frequency, dosage, etc.). In this way, drugs can be used to bring the patient to a more stable state, which is determined by the heart and respiratory rates. IAP and respiratory rate can also be used to control the ventilator or respirator. As IAP increases, the positive end-expiratory pressure (PEEP) delivered by the ventilator also increases to overcome this pressure. Indicators of inadequate ventilation can be seen in tissue oxygenation and / or spontaneous breathing rate, which can be viewed as an underlying signal for mechanical ventilation. This signal can be extracted during mechanical ventilation, or the loop controller can pause the mechanical ventilator to allow for more precise and accurate detection of the underlying respiratory rate / respiratory drive. This IAP, tissue oxygenation, and / or respiratory rate can be used to alert the healthcare provider to a worsening patient condition and / or provide automatic adjustments to ventilator settings, including respiratory rate, PEEP, %O2 inhaled, and other settings. In an ideal scenario, these parameters could be used by the loop controller to monitor and control therapy in a manner informed by machine learning and algorithmic adjustments. These are just a few examples, but many combinations exist. One or more parameters could be used to control one or more therapy devices.

[0145] 29 shows an embodiment of a loop controller in a patient environment. In this example, the loop controller receives patient parameter input from a sensing Foley catheter 2902. The sensing Foley catheter resides in the patient's bladder 2904 and includes a retention balloon 2908 and a pressure sensing balloon 2910. The sensing Foley catheter may include other sensors disclosed herein.

[0146] The sensing Foley catheter 2902 includes a retention balloon inflation lumen, a pressure balloon sensing lumen, and a urinary lumen. The pressure sensing balloon 2910 is connected to a pressure sensing lumen that is connected to a pressure transducer 2920, which may be incorporated into a controller 2928. The urinary lumen is connected to a urinary drainage tube 2912. The urinary drainage tube enters a urinary reservoir 2914, which may be connected to a urinary volume measurement device 2916 or may be incorporated into a controller as disclosed herein. Additionally, urinary output may be controlled by a urinary pump 2918, which may be located in the urinary drainage tube, incorporated into the controller, or located on the non-patient side of the controller as disclosed elsewhere herein.

[0147] The patient is shown with a ventilator mask 2922 and is fed through a ventilator tube 2924. The flow and supply of breathing gas is controlled by a ventilator 2926.

[0148] Loop controller 2928 is connected to urine volume measurement device 2916, urine pump 2918, pressure transducer 2920, and ventilator 2926 via connectors 2930, 2932, 2934, and 2936, respectively. The connectors may be wired or wireless. Alternatively, in this and other embodiments, some or all of urine volume measurement device 2916, urine pump 2918, and / or pressure transducer 2920 may be incorporated into controller 2928.

[0149] In this example, the loop controller 2928 receives patient parameter inputs from the urine flow measurement device 2916 and pressure transducer 2920 and can use the information provided by these parameters to control the urine pump 2918 and ventilator 2926. Parameters that the loop controller may receive from the sensing Foley catheter include IAP, respiratory rate, heart rate, stroke volume, tissue oxygenation, tissue perfusion pressure, temperature, urine specimen, urine output, and other parameters, including those disclosed herein.

[0150] For example, if the loop controller receives parameter information indicating that the patient's IAP is elevated, the loop controller may control the ventilator perfusion rate, pressure, or other parameter. The loop controller may incorporate data from one or more input parameters and control one or more therapeutic medical devices. For example, based on the received elevated IAP and abnormal tissue oxygenation parameters, the loop controller may control the output of the ventilator 2926 and the urine output rate by controlling the urine pump 2918.

[0151] The loop controller continues to monitor the patient parameters and adjusts the therapeutic medical device accordingly. Once the patient parameters normalize, the control of the therapeutic medical device is adjusted accordingly so that the feedback loop controlled by the loop controller is a closed loop. The loop can also be manually adjusted as needed, in which case the loop can be an open loop or a semi-closed loop.

[0152] FIG. 30 shows another example of a loop controller in a patient environment. In this example, a patient has an intravenous (IV) line 3002 in a vein in their arm. An IV fluid bag 3004 is elevated to allow IV fluid to drip and / or flow into the patient through the IV line 3002. A valve 3006 controls the flow of IV fluid to the patient by allowing the fluid to flow freely, restricting the flow, or stopping the flow. Here, the valve 3006 is controlled by the loop controller 2928 via connection 3008. The IV fluid bag 3004 may contain hydration fluid and / or medication. One or more IV bags may be involved, and one or more valves may control the IV bags. The loop controller can control the flow rate and contents of the IV fluid to the patient based on patient parameters received by the loop controller.

[0153] 31 shows another example of a loop controller in a patient environment. In this example, a patient has a drainage line 3102 inserted into their abdomen. Fluid from the abdomen may flow from the patient to a receptacle 3104. The fluid flow may be controlled by a pump 3106, which is controlled by the loop controller 2928 via connection 3108. The loop controller can control the flow of fluid from the patient to the reservoir 3104 via the pump 3106 based on received patient parameters. For example, if the IAP is abnormally high, the loop controller can increase the rate or initiate fluid removal from the patient by controlling the pump 3106.

[0154] FIG. 32 shows another example of a loop controller in a patient environment. In this example, a patient has an intravenous (IV) line 3202 in a vein in their arm. A drug infusion device 3204 controls the flow of a medication to the patient via the IV line 3202. Multiple drug infusion devices may be used. Here, the drug infusion device 3204 is controlled by the loop controller 2928 via connection 3206. The drug infusion device 3204 may contain any suitable fluid and / or medication. The loop controller may control the flow and content of the medication to the patient based on patient parameters received by the loop controller.

[0155] These examples show some of the medical devices that can be controlled by a loop controller, but any medical device can be used.

[0156] FIG. 33 is a detailed diagram of the loop controller. The loop controller 2928 can receive one or more patient parameter inputs from a sensing Foley catheter or other device. These inputs include, but are not limited to, urine output and volume, pressure profile from the bladder, and sensor information from the Foley catheter or other device. The pressure profile information from the bladder can be further analyzed to determine IAP, respiratory rate, heart rate, stroke volume, sepsis index, AKI index, and other patient parameters. This analysis may be performed in the loop controller 2928 or in a separate controller connected to the loop controller by either a wired or wireless connection. The connection may be over the Internet, an intranet, a WAN, a LAN, or other network, or locally via Bluetooth, Wi-Fi, etc.

[0157] The loop controller receives one or more inputs and analyzes the data to determine whether changes to the control of the therapy device are necessary. One or more medical devices can be controlled to bring the patient's parameters into a target range. Once the patient's target range is achieved, the loop controller returns the controlled medical devices to a standard state. The standard state may be different for each medical device and different for each patient. Target ranges for patient parameters similarly vary from patient to patient and depending on the patient's condition. For example, the target range for respiration rate may differ depending on whether the patient is sedated.

[0158] Embodiments of the present technology can also automatically adjust intravenous fluid or drug infusion rates based on feedback from cardiac output or sensed respiratory rate. In one such embodiment, a patient-controlled analgesia pump can be shut off if the respiratory rate becomes too low. Respiratory depression can be fatal in this group, and this safeguard prevents overdose. An automated feedback system can also be advantageous in mass resuscitation procedures, where fluid infusion can be adjusted based on intra-abdominal pressure, sounding an alert and slowing the infusion rate as intra-abdominal pressure increases to prevent abdominal compartment syndrome. Yet another automated feedback function could provide direct feedback to the ventilator system to provide optimal ventilation gas pressure. At increased intra-abdominal pressure settings, typical ventilator settings do not provide sufficient breaths to the patient. Automatic adjustment of ventilator settings based on intra-abdominal pressure feedback from this embodiment could advantageously provide optimal patient ventilation. Embodiments of the present technology can also be applied as corrections in the application or understanding of other diagnostic measurements. For example, increased intra-abdominal pressure can dramatically distort central venous pressure. Providing direct access to these data by a central venous pressure reporting system allows for automatic correction and accurate reporting of this important physiological parameter.Embodiments of the present technology may be used in a variety of other ways to automate therapy, including infusion of fluids that may further include active agents such as vasopressors or diuretics, in response to increases or decreases in cardiac output or other parameters.

[0159] Other inputs and outputs to the loop controller include nutrition provided via a feeding tube or intravenously, wound drainage, fecal output, sweat output, exhaled vapor output, etc.

[0160] In addition to directly controlling therapy devices, the loop controller 2928 may sound alarms, including audible alarms, email alarms, text alarms, pager alarms, etc. The loop controller 2928 may provide outputs to other systems for system integration, such as outputting information to electronic health records, other data archiving systems, or other systems. The loop controller 2928 may also receive inputs from various EHR, EMR, or other systems.

[0161] As a result of the data collected and / or analyzed by the sensing Foley catheter system, medical treatment may be administered to the patient, which may be medication administered automatically via a loop controller, or traditional medication administered manually, i.e., orally, via injection, etc.

[0162] Further medical diagnosis may also be performed based on the detection results of the Foley catheter system.

[0163] specific gravity

[0164] Urine specific gravity can be measured using pressure and ultrasound measurements with a sensing Foley catheter. Figure 34 shows a plot showing how ultrasound and pressure measurements of volume diverge with liquid density. The liquid being measured is a synthetic urine concentrate, with a specific gravity of approximately 1.100.

[0165] For a liquid with a specific gravity of 1.000, the two measurement techniques can be calibrated and will give the same volume measurement. However, as density increases, they begin to diverge. Since V=A*h and P=ρ*g*h, or V=A*ρ*g / P, increasing density due to pressure will increase the volume measurement. For ultrasound, V=A*h, v=h*2 / t, v=(E / ρ)^(1 / 2), so V=A*(E / ρ)^(1 / 2)*t / 2. V: Volume A: Cross-sectional area h: height of liquid P: Pressure ρ: liquid density g: gravity v: velocity of sound t: the time it takes for the sound to reflect E: bulk modulus of the liquid

[0166] Simply put, the denser the liquid, the higher the pressure, which distorts its measurements. At the same time, sound travels faster, distorting ultrasound measurements. By measuring how much they diverge, the density of the liquid can be determined. This assumes that the temperature is unchanged, but temperature can also be monitored to compensate for temperature variations. Volume measurement by ultrasound and pressure, as well as temperature measurement, can be performed using a sensing Foley catheter. In this way, a sensing Foley catheter combined with a controller can measure the specific gravity of urine.

[0167] Reduced condensation

[0168] Balloon catheters, especially those designed to remain in a human or animal body for a relatively long period of time, can leak over time. For example, a balloon inflated with air or another gas can leak air from the balloon over time. Alternatively, a balloon filled with a liquid can leak liquid over time. Vice versa. A balloon filled with air or gases present in liquids such as urine or blood can leak liquid into the balloon over time. This is especially true if the balloon is inflated at a relatively low pressure.

[0169] A sensing Foley catheter is an example of a balloon designed to be inflated at a relatively low pressure for a relatively long period of time. In this example, where the balloon is designed to measure pressure, the balloon can be inflated at a relatively low pressure and, as a result, can be manufactured from a relatively soft and thin material. The low inflation pressure and soft balloon material can cause fluid to leak into the balloon over time. Fluid in the pressure measurement balloon can adversely affect the very sensitive pressure measurement, especially if the fluid migrates into the catheter lumen where the pressure measurement is performed.

[0170] One embodiment to solve this problem is to place a very small pore or hydrophobic filter between the pressure measurement balloon and the pressure measurement lumen of the catheter. This allows the balloon to be inflated and continuously primed to maintain pressure, while still allowing pressure measurements to be taken through the catheter lumen. Air or gas can pass through the filter, but fluid cannot.

[0171] Another embodiment involves making the balloon from a low moisture permeable material.

[0172] Another embodiment involves re-infusing the gas within the balloon by alternately applying vacuum and pressure to the balloon through either a single lumen or multiple lumens.

[0173] Another embodiment involves circulating gas within the balloon by having multiple lumens access the balloon: one lumen can be used to introduce gas into the balloon and another lumen can be used to aspirate gas from the balloon.

[0174] Another embodiment includes the use of a desiccant within the balloon, the balloon lumen, the gas supply to the balloon, or any combination thereof.

[0175] FIG. 35 shows the distal end of a Foley-type balloon catheter that may benefit from clotting reduction. In this example, the balloon catheter is designed to be placed in a patient's bladder to aid in the drainage of urine from the bladder. The catheter includes a retention balloon 3506 that secures the catheter within the bladder. A catheter shaft 3502 contains the catheter's lumen. An opening 3504 allows urine from within the bladder to drain through the catheter and out the proximal end of the catheter (not shown). An opening 3508 is for inflating and deflating the retention balloon. A pressure sensing balloon 3510 inflates and deflates through an opening 3512. The pressure sensing balloon 3510 transmits pressure signals from within the bladder through a pressure lumen in the catheter shaft to a pressure transducer near the proximal end of the catheter.

[0176] Under certain circumstances, over time, fluid may leak into the pressure balloon 3510. Additionally, fluid may migrate from within the pressure balloon 3510 through the openings 3512 and into the catheter shaft 3502. Fluid within the pressure lumen can adversely affect pressure measurements from the pressure balloon. As a result, it is desirable to prevent fluid from migrating from within the pressure balloon through the openings 3512 or, if possible, reduce the amount of fluid entering the pressure balloon.

[0177] FIG. 36 shows an embodiment of a filter within a balloon. The filter 3602 is located between the interior of the balloon 3510 and the pressure lumen inside the catheter opening 3512. The filter 3602 is preferably made of a material that allows gas to pass through but not fluid. For example, the filter can be made from a hydrophobic membrane such as Versapor, PTFE, or ePTFE. The filter may also be made of a polymer such as nylon or other suitable material. The pore size may be about 3 microns, or about 5 microns, or in the range of about 0.2 microns to about 5 microns, or in the range of about 5 microns to about 10 microns. The filter thickness ranges from about 6 mils to about 12 mils. Alternatively, the filter thickness may range from about 1 mil to about 6 mils. The pore size is related to the sensitivity of the balloon. For example, a filter with a 5 micron pore size may be suitable for a balloon inflated to about 5 mmHg to about 20 mmHg and can detect pressure differences down to a resolution range of 0.01 mmHg. If the pressure measured through the pressure balloon needs to be less sensitive, a smaller pore filter can be used. If the pressure measured through the pressure balloon needs to be more sensitive, a larger pore filter can be used.

[0178] 36 shows a filter in the form of a tube that surrounds and completely covers the catheter shaft at the opening 3512. The filter may be adhered at its ends to the catheter shaft using a suitable adhesive or other means such as heat shrink. The seal between the filter and the catheter is ideally gas impermeable, so that gas entering or leaving the balloon 3510 through the opening 3512 must pass through the filter 3602.

[0179] Figure 37 is another embodiment of the invention in which the filter includes a smaller catheter shaft mounted within a balloon. The catheter shaft 3704 within the balloon is a smaller diameter than the catheter shaft 3706 that is not underneath the balloon. This prevents the added bulk of the filter 3702 from increasing the diameter of the deflated balloon.

[0180] FIG. 38 shows the embodiment shown in FIG. 37 with the balloon deflated, showing that the reduced diameter of the catheter shaft below the balloon area prevents significant balloon catheter inflation.

[0181] 39 shows another embodiment of an under-balloon filter. The filter 3902 in this embodiment does not wrap completely around the catheter shaft, but instead is a flat or curved filter piece that is adhered to the catheter shaft via adhesive or other suitable means. The adhesive preferably seals the filter completely around its edges without encroaching on the balloon inflation / deflation / pressure measurement opening 3512.

[0182] FIG. 40 shows another embodiment of a filter 4002 with a shorter filter length.

[0183] FIG. 41 shows another embodiment of a balloon catheter with a filter. In this embodiment, the balloon catheter has two lumens in fluid communication with the balloon. Filter 4102 covers opening 4104, while opening 4106 is uncovered. In this embodiment, openings 4104 and 4106 may each access separate lumens in the catheter, or the same lumen. In embodiments in which they access separate lumens, balloon inflation, deflation, and pressure measurements may be performed through either lumen. For example, pressure measurements may be taken through the lumen in fluid communication with opening 4106 until fluid accumulation in the lumen adversely affects the pressure measurements. At this point, the pressure transducer may be switched to the lumen in fluid communication with opening 4104, and pressure measurements may be taken through the lumen that is free of fluid.

[0184] Alternatively, pressure measurements may be taken through the lumen in fluid communication with opening 4106 until the accumulation of fluid within the lumen adversely affects the pressure measurements. At this point, gas can be introduced into the lumen in fluid communication with opening 4106 to remove fluid from the lumen. Simultaneously, gas can be drawn from the balloon through the lumen in communication with opening 4104. In this manner, fluid is removed from the lumen in communication with opening 4106, and pressure measurements can resume through that lumen. This line-clearing procedure can be programmed to occur periodically.

[0185] Figure 41 shows two balloon openings 4102 and 4106 on different sides of the catheter, with a filter 4104 covering only one of the openings. Alternatively, Figure 42 shows an embodiment similar to that of Figure 41, except that there may be two openings 4204 and 4206 side by side, with a filter 4202 covering only one of the openings.

[0186] 43 shows an embodiment of the invention in which a filter 4302 covers a larger opening 4304. A larger opening may be desirable to obtain more accurate pressure measurements from the balloon. Furthermore, the addition of filter 4304 may allow for a larger opening due to the extra integrity that the filter, and possibly its adhesive means, provides to the area of ​​the catheter around the opening 4304.

[0187] Figure 44 shows an embodiment of the invention in which a filter 4402 is attached to a catheter shaft via a heat shrink tubing segment 4404. This allows for an airtight seal between the filter and the catheter while ensuring that the catheter opening 4406 remains clear.

[0188] Figure 45 shows an embodiment similar to that of Figure 44, except that the catheter shaft is collapsed below the balloon area. This allows the balloon to be deflated without causing a bulge in the catheter to which the filter is attached. The filter 4502 is attached to the catheter shaft via a heat shrink tubing segment 4504. This allows for an airtight seal between the filter and the catheter while ensuring that the catheter opening remains clear.

[0189] FIG. 46 shows an embodiment of the invention in which a filter 4602 is attached to the inside of the catheter at the opening.

[0190] FIG. 47 illustrates an embodiment of the invention in which the balloon has two access lumens 4702 and 4704. In this embodiment, the balloon catheter has two lumens in fluid communication with the balloon. In this embodiment, openings 4702 and 4704 may each access separate lumens in the catheter or the same lumen. In embodiments in which they access separate lumens, balloon inflation, deflation, and pressure measurements can be performed through either lumen. For example, pressure measurements can be taken through the lumen in fluid communication with opening 4702 until fluid accumulation in the lumen adversely affects the pressure measurement, or for a set period of time. At this point, gas can be introduced into the lumen in fluid communication with opening 4702 to remove fluid from the lumen. Simultaneously, gas can be drawn from the balloon through the lumen in fluid communication with opening 4704. The reverse can also be done—fluid can be introduced into the lumen in fluid communication with opening 4704 and removed from the lumen in fluid communication with opening 4702. In this manner, fluid can be removed from the lumen communicating with opening 4702 and pressure measurements can resume through that lumen. This line clearing procedure can be programmed to occur periodically. Although openings 4702 and 4704 are shown opposite each other here, the openings may also be offset from each other.

[0191] Figures 48 and 49 show two different pressure balloon designs, but any suitable design and / or shape may be used. Depending on the balloon material, the balloon can be manufactured in a variety of ways. Some materials are suitable for blow molding, while others are suitable for dip molding. Other manufacturing techniques, such as resistance heat sealing, may be used as well. Figure 48 shows an example of a blow molded balloon. Figure 49 shows an example of a dip molded balloon.

[0192] Some examples of materials from which the balloon can be made include urethane, polyurethane, polyethylene, nylon, polyvinylidene fluoride, or any other suitable polymer or other material, or any combination of materials.

[0193] Balloon coatings may also be utilized to reduce the fluid permeability of the balloon. An example of such a coating is poly(p-xylylene) polymer, or parylene.

[0194] In some embodiments, it may be desirable to prevent water vapor from entering the pressure balloon. In these embodiments, a water or fluid impermeable material may be used for the balloon. Some of the materials mentioned herein are suitable. Additionally, biaxially oriented polyethylene terephthalate (BoPET), often referred to by the brand name Mylar, may be used. Metallized polymers or other suitable materials may also be used.

[0195] In some embodiments, the sensing Foley-type catheter is configured to report the presence of water droplets or other obstructions in an air-filled lumen (such as a pressure lumen) and subsequently process or break down the droplets. Particularly in hypothermic settings, moisture in the air lumen can condense and form obstructive water droplets. Water droplets in an air-filled lumen (or air bubbles in a water-filled lumen) can disrupt or complicate the pressure signal due to the surface tension of the water. Therefore, the pressure transmission lumen in some embodiments of the disclosed technology can include hydrophilic features (such as a coating on the wall of the lumen itself or hydrophilic fibers extending the length of the lumen) to wick moisture away from the lumen to maintain an uninterrupted, continuous air channel. In some embodiments, a hygroscopic composition (e.g., silica gel) can be used along the air inflation line or within the air inflation lumen itself to trap water or humidity. In some embodiments, the hygroscopic composition can be included within the catheter, eliminating the need to service the air inflation circuit to replace this material.

[0196] In some embodiments, dried air or gas may be used in the pressure lumen and pressure balloon to prevent moisture buildup.

[0197] In some embodiments, a hydrophobic or hydrophilic coating may be used on the pressure lumen and / or pressure balloon.

[0198] Gas Content

[0199] Another embodiment involves measuring the relative oxygen or other gas content of urine or tissue using a hydrophobic filter or membrane as an interface with urine in the bladder or the mucosal lining of the urethra.

[0200] In some embodiments of a sensing Foley catheter, it is desirable to measure changes in tissue and / or urine gas content or gas content over time. Potential gases of interest include oxygen, carbon dioxide, nitrogen, gases associated with anesthesia, or other gases. In some embodiments, the membrane is permeable to gases but not to liquids; for example, a hydrophobic membrane or other suitable membrane may be used. The pore size of the hydrophobic membrane may be about 5 microns. Alternatively, the pore size of the hydrophobic membrane may be about 3 microns to about 7 microns.

[0201] Figure 50 shows a sensing Foley catheter with an oxygen permeable membrane. A retention balloon 5002 is in fluid communication with an inflation / deflation port 5010. Urine passes through the catheter through opening 5004 and out port 5012, which is in fluid communication with opening 5004. A pressure sensing balloon 5006 is in fluid communication with lumen 5014. A membrane 5008 covers an opening at the distal end of the catheter that is in fluid communication with lumen 5016.

[0202] Figure 51 shows a sensing Foley catheter with an oxygen permeable membrane similar to that shown in Figure 50, except that the membrane 5108 is between the pressure sensing balloon 5106 and the retention balloon 5102. The urinary opening 5104 can be located anywhere distal to the retention balloon 5102.

[0203] Figure 52 shows an embodiment of a sensing Foley catheter in which a membrane 5204 is incorporated into a gas sensing balloon 5202. In this figure, the gas sensing balloon 5202 is distal to the pressure sensing balloon 5206, although another embodiment in which this is not the case is shown in Figure 53. The gas sensing balloon 5202 may be made from silicone, a polymer, or any other suitable material.

[0204] The membrane material may be similar to the hydrophobic membrane materials described in other embodiments herein. The membrane is permeable to gases, or certain gases, but not to liquids such as urine. In this manner, gases can pass through the membrane and enter the catheter to measure the gas content of tissue and / or urine and / or changes in gas content over time. Gases that may be measured include oxygen, nitrogen, carbon dioxide, or other gases.

[0205] The catheter can be placed in the patient so that the membrane is in either the bladder or the urethra. While the membrane is shown here on a sensing Foley catheter with a pressure-sensing balloon, the gas-permeable membrane can be placed on any indwelling catheter, including catheters in blood vessels or other body cavities. The membrane may be in direct or indirect contact with fluid, gas, or body tissue.

[0206] 54 shows a controller that controls the measurement of oxygen or other gases. The controller is generally external to the patient and connects to the catheter via a port, such as port 5016. The controller may also control pressure Foley functions or other functions of the Foley sensing catheter.

[0207] Gas measurement controller 5402 is shown here with a representation of catheter 5404 and gas transfer membrane 5406. Gas measurement controller 5402 includes an air or gas inlet 5408, an air or gas exhaust 5410, a pump 5412, an oxygen or other type of sensor 5414, and a check valve 5416.

[0208] In this embodiment, a pump 5412 periodically pushes a small amount of air or other gas through the tubing and into the catheter. The air passes through a membrane "window" 5406, and the oxygen content of the air varies based on the oxygen content of the mucosal lining (if the gas transport membrane is in the urethra) or urine (if the gas transport membrane is in the bladder). Further downstream (back to the gas measurement controller box 5402), a fiber optic or other type of oxygen sensor is used to measure the oxygen percentage of the air. The pump may run for a short period of time to allow the air in the system time to equilibrate with the tissue / fluid.

[0209] Check valve 5416 helps to limit mixing of air passing through the system with outside air or air from a previous measurement interval.

[0210] The measured oxygen or other gas content may be very low. The measurements may indicate either absolute or relative gas levels. For example, the gas measurement controller's measurements may indicate the patient's relative oxygen content over time to indicate changes in the patient's condition.

[0211] FIG. 55 shows a schematic diagram of how a gas measurement controller interacts with a catheter to measure gas content in urine or a patient's tissues. Catheter 5502 includes gas measurement lumens 5506 and 5508 in fluid communication with a urine drainage lumen 5504 and a gas transfer membrane 5510. Lumen 5506 contains air or other gas entering the catheter, and lumen 5508 contains air or other gas exiting the catheter after a carrier gas has passed through the gas transfer membrane. The level of oxygen or other gas in the drainage gas is measured to determine the oxygen level or changes in oxygen level in the patient's urine and / or tissues. Incoming gas measurement lumen 5506 may be open to the atmosphere or other source, or may be a closed system so that gas in lumens 5506 and 5508 is continuously circulated, allowing changes in gas content to be easily determined over time. That is, air or gas inlet 5408 and air or gas outlet 5410 of FIG. 54 may be fluidly connected to one another.

[0212] If the incoming gas measurement lumen 5506 is open to atmosphere, the pump can be operated intermittently to allow more time for the gas in the gas measurement lumen to equilibrate across the membrane surface, resulting in higher intermittent concentrations of the measurement gas and therefore more sensitive measurements.

[0213] The pump can be run continuously or intermittently, regardless of whether the system is closed or open, but running it intermittently in open system mode allows for more sensitive measurements. In closed system mode, trends may be more apparent as the measurement gas in the system equilibrates with the gas levels in the urine, body fluids, or tissues being measured.

[0214] In this embodiment, the ureteral lumen and the gas measurement lumen are separate. However, as shown in Figure 56, a gas transport membrane may be located between the ureteral lumen and the gas measurement lumen, with gas transport membrane 5602 in fluid communication with the ureteral lumen.

[0215] 57A and 57B show an embodiment of a gas measurement add-on component. The gas measurement component 5702 may be inserted between the sensing Foley catheter 1000 or any Foley catheter and the urinary drainage tube 1001 or any urinary drainage tube. The gas measurement component 5702 includes a hydrophobic filter 5704, which may be made of materials disclosed elsewhere herein. The gas inlet lumen 5706 and the gas outlet lumen 5708 allow gas to pass over the filter 5704, which is in gas communication with the urine in the drainage system. Air or gas near the filter 5704 will very quickly come into equilibrium with the gas in the urine in the drainage system. FIG. 57B shows the airflow path before and after the filter 5704. The gas outlet lumen 5708 is in fluid communication with a controller (not shown here) that analyzes the gas in the lumen for associated gases. Gas inlet lumen 5706 may be open to atmosphere, another gas, or may be in a closed loop with gas outlet lumen 5708 within the controller. The controller may be the same controller that measures urine output as described elsewhere herein, or it may be a separate controller. Lumens 5706 and 5708 may be integrated into drainage tube 1001 or may be separate. Gas measurement component 5702 may be a separate component as shown here, or may be integrated into vent barb 1016. Alternatively, gas measurement component 5702 may be located elsewhere within the system.

[0216] Detecting / determining specific conditions

[0217] Figure 58A shows a table listing parameter combinations that allow fingerprints or signatures (parameter combinations) for different indicators of AKI (prerenal, intrinsic, and obstructive). Furthermore, there are fingerprints or signatures regarding the timing of parameter changes, and the cause of AKI may also be identified (e.g., it is plausible that some parameters change faster in intrinsic AKI caused by glomerulonephritis than in intrinsic AKI caused by acute tubular necrosis). This multiparametric approach may also facilitate the selection of effective therapies to treat AKI, as different causes of AKI have different effective treatments (e.g., recombinant alkaline phosphatase is effective for treating intrinsic (septic) AKI but not for treating non-septic AKI).

[0218] Figure 58B shows a table listing parameter combinations that allow fingerprints or signatures (parameter combinations) of different indicators of sepsis, AKI, and acute respiratory distress syndrome (ARDS). These signatures include increases, decreases, or both in various patient parameters, such as urine output, heart rate, respiratory rate, temperature, stroke volume, cardiac output, and abdominal perfusion pressure. Abdominal perfusion pressure is the mean arterial pressure (MAP) minus the intraperitoneal pressure (IAP). Mean arterial pressure is equal to diastolic pressure (DP) plus 1 / 3 of the pulse pressure (PP). (Pulse pressure is equal to systolic pressure minus diastolic pressure.) In essence, MAP = DP + 1 / 3 PP.

[0219] Other patient parameters may also be used. One, some, or all relevant parameters may be used by the controller to communicate a diagnosis or risk to the user or another device. Patient parameters captured by a sensing Foley catheter system may be used alone or in combination with parameters obtained elsewhere, such as an EKG, a blood pressure measurement device, or information from an EMR.

[0220] The sensing Foley catheter system provides real-time, automated, and accurate physiological parameter monitoring for the early detection of various medical conditions. Real-time multivariate (point value) and time series (trend) analysis of these high-frequency data streams can be used to inform machine learning-based models to develop sensitive physiological signatures for early sepsis onset (or other medical condition determinations). This enables earlier diagnosis and intervention, leading to improved clinical outcomes. Features associated with data related to physiological changes occurring before and / or during the onset of a specific medical condition strengthen relevant parameters and weaken less relevant parameters, building or breaking connections. This allows the controller to use algorithms to distinguish medical conditions from one another and from normal and other medical conditions.

[0221] Some embodiments of the present invention can measure urine output immediately after a patient is administered a diuretic. This type of test is a strong indicator of whether a patient with AKI will progress to a more severe stage or die. If a patient's urine output increases after administration of a diuretic, this indicates that the patient is unlikely to progress to a more severe stage of AKI. If a patient's urine output does not increase significantly after administration of a diuretic, this indicates that the patient is likely to progress to a more severe stage of AKI. The present invention can rapidly and accurately measure urine output in real time. Therefore, a response to a diuretic can be detected more quickly (within minutes rather than hours) than with conventional urine measurement techniques.

[0222] This test can be automated with a controller that provides a controlled dose of diuretic, followed by monitoring urine output over minutes or hours, preferably minutes. The diuretic administered can be furosemide or another suitable loop or other diuretic. Diuretic administration and data collection can be as disclosed in Chawla LS, Davison DL, Brasha-Mitchell E, Koyner JL, Arthur JM, Tumlin JA, Shaw AD, Trevino S, Kimmel PL, Seneff MG. Development and standardization of a furosemide stress test to predict the severity of acute kidney injury. Crit Care. 2013 Sep 20;17(5):R207, incorporated herein by reference.

[0223] In addition to detecting AKI, the present invention can detect urinary tract infection (UTI), as indicated by decreased oxygen tension, carbon dioxide levels, increased specific gravity, and relatively stable urine output and conductance. Detection of UTI can be achieved in the absence of AKI, and possibly in the presence of AKI, by combining urinary markers with a unique fingerprint of UTI. The distinctive characteristics of a unique UTI can alert clinicians to the presence of a UTI.

[0224] In addition to detecting AKI and UTI using the described parameters, these parameters may also be used in conjunction with intra-abdominal pressure (IAP), respiratory rate (RR), heart rate (HR), cardiac output (CO), relative stroke volume (RSV), temperature (Temp), pulse pressure (PP), urinary conductance (UC), urinary volume (UO), and / or stroke volume (SV) readings (already used to detect conditions such as intra-abdominal hypertension (IAH)), abdominal compartment syndrome (ACS), and sepsis. Adding IAP, RR, HR, CO, RSV, Temp, PP, UC, UO, and / or SV measurements to the algorithms described herein may improve the sensitivity and specificity of detecting AKI or UTI. Meanwhile, adding measurements obtained by the present invention to IAP, RR, HR, CO, RSV, Temp, PP, UC, UO, and / or SV measurement algorithms may increase the sensitivity and specificity of detecting IAH, ACS, or sepsis. Other clinical applications include the treatment of trauma and burns.

[0225] In addition to absolute measurements of IAP, RR, HR, CO, RSV, temperature, PP, UC, UO, gas concentrations, and / or SV, trend data for these parameters can also be used to detect IAH, ACS, sepsis, or other conditions. For example, the slope of the values ​​of these parameters over time and / or the variability of the values ​​of these parameters over time can also be used. Another example of using data trending is the use of pulse pressure waveform analysis and pulse wave velocity (or pulse transit time). Pulse transit time can be determined by obtaining a cardiac signal, such as an EKG, from the leads of a sensing Foley catheter, and determining the time it takes for the pulse wave pressure signal to reach the bladder. Multiple parameters and / or parameter trends can be used to determine the presence of IAH, ACS, sepsis, or other conditions.

[0226] Examples of use cases for trend data include:

[0227] A decrease in UO2 (when it does not) with stable vitals may indicate acute kidney injury. If stroke volume is decreased, the kidneys may be ischemic. A sudden increase in urine output with stable vitals may indicate toxic acute kidney injury.

[0228] An increase in respiratory rate accompanied by a decrease in stroke volume may indicate a pulmonary embolism, hemorrhage, or other volume decrease.

[0229] An increased respiratory rate in the setting of stable vitals may indicate impending airway obstruction.

[0230] A decrease in respiratory rate in the setting of stability of other parameters may indicate a narcotic overdose, which is a major problem in patient-controlled analgesia.

[0231] Increasing intraabdominal pressure (IAP) and increasing urine output in the setting of stable stroke volume may be indicators of impending fluid overload.

[0232] An increase in IAP with a decrease in UO and cardiac output may be indicative of cardiopulmonary dysfunction, which may be due to fluid overload, sepsis, etc.

[0233] The present invention can be used in various hospital settings (e.g., emergency rooms, operating rooms, intensive care units, and wards). At any time, the device can be used to monitor the progression of AKI and whether it is improving or decreasing. The algorithm functions to alert clinicians to newly developed AKI cases or changes in AKI status. To detect the onset of AKI, the device may be placed before kidney injury occurs (e.g., in patients undergoing cardiac surgery to detect whether kidney injury begins during surgery). It may also be placed when kidney damage is already present to detect the extent of injury at that time. The device can also be used to monitor response to treatment / therapeutic interventions (e.g., renal replacement therapy, fluid resuscitation).

[0234] Alternative Embodiments

[0235] Embodiments of the present technology may also report patient movement in the detection or diagnosis of seizure disorders. In this embodiment, pressure fluctuations may activate EEG or recording devices, allowing for periods of intense monitoring during suspected seizure episodes. Additionally, or instead, pressure, acoustic, or other sensors may be used to detect bowel activity, including peristalsis, patient movement, seizure activity, patient shivering, cough frequency, cough severity, sleep duration, sleep quality, speech detection, and patient compliance (movement or lack thereof), and alert a healthcare provider that the patient is not moving and needs to turn or rotate. This movement-related information may also be relayed to hypothermia, drug delivery, or other devices to control or reduce seizure activity, shivering, and / or coughing.

[0236] In some embodiments, the sensing Foley-type catheter is configured to report the presence of water droplets or other obstructions in an air-filled lumen (e.g., a pressure lumen) and subsequently process or break down the droplets. Particularly in hypothermic settings, moisture in the air lumen can condense and form obstructive water droplets. Water droplets in an air-filled lumen (or air bubbles in a water-filled lumen) can disrupt or complicate the pressure signal due to the surface tension of the water. Therefore, the pressure-transmitting lumen in some embodiments of the disclosed technology can include hydrophilic features (e.g., a coating on the wall of the lumen itself or hydrophilic fibers running the length of the lumen) to wick moisture away from the lumen to maintain an uninterrupted, continuous air channel. In some embodiments, a hygroscopic composition (e.g., silica gel) can be used along the air injection line or within the air injection lumen itself to trap water or humidity. In some embodiments, the hygroscopic composition can be contained within the catheter, so that the inflation circuit does not need to be serviced to replace this material.

[0237] In some embodiments of the disclosed technology, as described in more detail above, air may be intermittently (and automatically) injected and extracted from the pressure-sensing balloon to maintain a constant, optimally primed state of the balloon. In the case of wicking fabric or a hydrophilic coating within the lumen, the extraction of air may also contribute to removing and trapping water from the air line. In the example of a liquid-filled lumen, hydrophilic fabric or a hydrophilic coating inside the pressure lumen provides a similar benefit in allowing the lumen to handle air bubbles. In this example, air bubbles could distort the signal, but the hydrophilic coating within the catheter lumen reduces the surface tension at the air-water interface.

[0238] Additionally, custom extrusions and lumen shapes can be used to prevent blockages in the case of lumens filled with liquid and / or air. In some embodiments of the present technology, for example, a Foley-type catheter can have a lumen with a star-shaped cross-sectional profile. Such lumens are generally not susceptible to blockages caused by water droplets because the droplets tend to coalesce on themselves and move away from the hydrophobic walls. This behavior tends to prevent the cross-sectional space from filling, leaving the vent tube open around the droplets and allowing communication with the sensor. The same logic applies to air bubbles in water within a hydrophilic, star-shaped water lumen. In this example, the hydrophilic liquid clings to the walls, allowing a continuous water column that displaces the air bubbles to the center of the lumen. The same applies to hydrophobic liquid within a hydrophobic lumen. In some embodiments, the catheter can include an air channel and a sensor integrated into the catheter itself, or a fluid lumen that can return pressure to the sensor.

[0239] The drainage tube is a multi-lumen tube that houses a urinary drainage line, a pressure lumen, and a thermocouple wire, and is connected to the barb on one end and to the controller on the other end.

[0240] Foley catheters can be extruded with BaSO4 or fitted with radiopaque markers for fluoroscopic observation.

[0241] The thermistor at the tip of the catheter can be secured in place using a number of extrusion profiles and assembly techniques.

[0242] In some embodiments, the sensing Foley catheter may include a blood pressure sensing element, which may take any of several forms. In one embodiment, the blood pressure sensing element includes a pressure delivery balloon (either a separate, dedicated balloon or a device-retaining balloon or a balloon in fluid communication with the pressure-sensing balloon) that can be inflated and optically analyzed to determine the pressure of the blood vessels in the bladder or urethra, compressing and blanching them and stopping blood flow. This approach provides a measurement of the perfusion pressure of the tissue adjacent to the pressure delivery balloon, which reflects both systemic blood pressure and vascular resistance. This embodiment of the perfusion pressure device may be used to provide early detection or monitoring of various acute or emergency medical conditions, such as sepsis, shock, and hemorrhage, and may be particularly advantageous for detecting these conditions at an early stage. In predicting sepsis, embodiments of the present invention may receive white blood cell count information to better predict sepsis.

[0243] Along with the general methodological aspect of intermittent inflation within a lumen, cavity, or bodily tissue to provide compression of the vasculature, other modalities may also be used to detect when tissue has blanched or ischemic. Embodiments of this device and associated methods may also be used to detect perfusion pressure in other regions of the body using intermittently inflatable members and optically detect blood flow or the presence of blood.

[0244] Tissue perfusion information may be provided by sensors placed on the shaft of the catheter so that they contact the urethral wall when the catheter is in place. These sensing techniques include microdialysis, pyruvate, lactate, pO2, pCO2, pH, perfusion index, near-infrared spectroscopy, laser Doppler flowmetry, urethral capnography, and cross-polarized spectroscopy. Any of these tests can be performed on urine or the bladder wall itself to produce a measurement of tissue perfusion.

[0245] Another embodiment of the sensing Foley catheter system includes a clearing mechanism embodiment that includes a device and / or port for positive airflow near the beginning of the drainage line. The positive airflow promotes drainage by forcing urine down the drainage line. The positive airflow device may include a one-way valve at the end of the urinary catheter that allows urine to flow only toward the urine collection device and prevents air from entering the catheter.

[0246] In some embodiments, the urine removal mechanism comprises a coating on the inside of the urinary drainage tube to reduce surface tension and facilitate drainage, hi one aspect, the coating is a hydrophobic polymer, including but not limited to PTFE or FEP.

[0247] In yet another embodiment, the clearing mechanism comprises a tubular hydrophobic vent filter that can be inserted into the drainage lumen of the device to allow air to escape along its entire length. Segmented hydrophobic vents can also be incorporated at regular intervals to ensure air escapes from the tubing as it passes through these areas. In this embodiment, the hydrophobic vents are spaced at least 1-2 feet apart to prevent submersion of the vents in urine. By providing redundancy, multiple vents / filters prevent failure of a single filter / vent due to flooding. In an ideal configuration, the vents are made of PTFE or ePTFE material and secured with barbs or grommets to the tubing at intervals for ease of manufacturing. In an alternative embodiment, the vents take the form of slits or spirals that run the length of the drainage tubing, thereby allowing air to escape the tubing at any point. This eliminates position dependency of the drainage tubing when preventing and / or eliminating airlocks.

[0248] In another embodiment, airlock is prevented by an expandable drainage tube that prevents air pockets from forming in the higher sections of the tube and urine from collecting in the lower sections. The expandable tube keeps the tube as straight as possible between the urinary catheter and the collection bag, preventing air pockets from forming in the higher sections of the tube and urine from collecting in the lower sections. In one aspect, the expandable drainage tube is composed of multiple expandable sections that can be extended or collapsed to fit the distance from the patient to the collection bag. In another aspect, the drainage tube is pleated to form an accordion, allowing it to be extended, collapsed, or deformed as needed. In yet another aspect, the tube is coiled. In yet another aspect, the drainage tube is retractable by a spring coil that wraps the tube around a wheel to achieve the appropriate length.

[0249] Relative cardiac output and relative tidal volume are also calculated based on the deflection of the pressure sensor and / or other force gauge. When sampled at a sufficient frequency (e.g., 1 Hz or higher), respiratory excursions can be quantified relative to the amplitude of the excursion during catheter placement. Larger excursions are generally associated with heavier breathing, or an upward drift in the baseline, and higher peritoneal pressure. The small peak of the oscillatory respiratory wave caused by the expanding heart can also be tracked using faster sampling rates (e.g., 5 Hz or higher), and the amplitude of this wave can be used in settings of relatively constant peritoneal pressure to determine relative cardiac output in settings of known, stable peritoneal pressure, absolute stroke volume, and / or cardiac output.

[0250] Intra-abdominal pressure or bladder pressure, as sensed by embodiments of the disclosed technology, may also be used to detect a patient's level of movement (e.g., it may vary between substantially no movement and high levels of movement) and report the movement level to a healthcare provider. Short bursts of peaks and valleys in bladder pressure activity serve as a proxy for body movement, as such a bladder pressure profile is a strong indicator that the patient is using their abdominal muscles, for example, to sit up or get out of bed. This embodiment may be particularly beneficial for patients at risk of falling. In patients at risk of falling, a healthcare provider may be notified that the patient is sitting and respond accordingly. Alternatively, the device may be used to report patient inactivity and / or a lack of patient movement.

[0251] The pulse oximeter element allows for the determination of blood oxygen concentration or saturation and can be placed anywhere along the urethral length of the catheter. In some embodiments, one or more sensors are placed within the device's lumen to ensure access to the urethral mucosa. This technique allows healthcare providers to decompress the bladder with a urethral catheter and acquire pulse oximetry data in a reproducible and accurate manner. The power source for the pulse oximetry can be integrated into the urine collection container or the catheter itself. In some embodiments, the pulse oximeter is reusable and the catheter interface is disposable; in this configuration, the pulse oximeter is reversibly attached to a disposable catheter and removed when oxygen measurements are no longer needed. Sensing Foley catheter embodiments may include an optically transparent or sufficiently transparent channel for the oximetry signal, such as a fiber optic cable, a transparent window, and an interface for a reusable oximeter. This method and device for urethral pulse oximetry may be used in combination with any of the other embodiments detailed herein or may be a standalone device.

[0252] To prevent infection, an antimicrobial coating or material impregnated with an antimicrobial compound can be used on the sensing Foley catheter. Examples of antimicrobial coatings / materials include silver, silver citrate, parylene, or other suitable materials.

[0253] Pulmonary blood volume variability may also be determined by sensing with a Foley catheter system to aid in the assessment of the presence or risk of heart failure. Decreased left ventricular function leads to increased pulmonary blood volume (PBV) or decreased pulmonary blood volume variability. PBV variability is defined as the change in PBV over time during the cardiac cycle. PBV can be determined as the product of cardiac output and pulmonary transit time (PTT). Cardiac output can be determined as the product of stroke volume and heart rate, where stroke volume is the area under the flow-time curve for one cardiac cycle. Pulse transit time can be obtained by examining the delay between the appearance of the QRS complex on the EKG and the bladder signal. EKG signals can be acquired from separate EKG leads, leads integrated into the sensing Foley catheter, leads integrated into the catheter insertion kit, or elsewhere. EKG leads can be used anywhere in the system to read EKG signals from within the urine. Two leads can be used to more accurately determine pulse transit time.

[0254] It has been shown that stroke volume, ejection fraction, and PBV variability decrease after myocardial infarction, with the greatest change observed in PBV variability. Therefore, assessing PBV variability and identifying a decrease in PBV variability may be a strong indicator of heart failure or the risk of heart failure.

[0255] Data collected by the sensing Foley catheter system is stored in a database and analyzed for trend analysis and other uses. For example, data can be collected from multiple patients and aggregated anonymously to better treat, monitor, or predict future patient behavior. For example, data collected over time regarding heart rate, respiratory rate, temperature, infection, etc., can be aggregated and analyzed by the controller to find trends, such as relationships between various parameters and outcomes. For example, a particular trend in temperature, alone or in combination with other parameters, may be a predictor of infection, the development of sepsis, ARDS, and / or AKI. While Figure 58 illustrates some known examples, other currently unknown trends may emerge from aggregated patient data.

[0256] Data collected by the sensing Foley catheter system can be integrated with an electronic health record (EHR) or electronic medical record (EMR) and / or other systems. Data collected by the sensing Foley catheter system controller can be directly or indirectly connected to an EMR / EHR system. Data such as patient demographics and medical history data from the EMR / EHR can also be integrated with the sensing Foley catheter system.

[0257] Data Processing System Example

[0258] Figure 60 is a block diagram of a data processing system that may be used in any embodiment of the present invention. For example, system 6000 may be used as part of a controller, as illustrated in some embodiments herein. Note that while Figure 60 illustrates various components of a computer system, it is not intended to represent the particular architecture or manner in which the components are interconnected; such details are not germane to the present invention. It will also be understood that network computers, handheld computers, mobile devices, tablets, mobile phones, and other data processing systems having fewer or perhaps more components may also be used with the present invention.

[0259] As shown in Figure 60, a computer system 6000 in the form of a data processing system includes a bus or interconnect 6002 coupled to one or more microprocessors 6003 and ROM 6007, volatile RAM 6005, and non-interconnect 6002. Microprocessor 6003 is coupled to cache memory 6004. Bus 6002 interconnects these various components and interconnects these components 6003, 6007, 6005, and 6006 to a display controller and display device 6008 and to input / output (I / O) devices 6010, which may be a mouse, keyboard, modem, network interface, printer, and other devices known in the art.

[0260] Input / output devices 6010 are typically coupled to the system via an input / output controller 6009. Volatile RAM 6005 is typically implemented as dynamic RAM (DRAM) and requires continuous power to refresh or maintain data in memory. Non-volatile memory 6006 is typically a magnetic hard drive, magneto-optical drive, optical drive, or DVD RAM, or other type of memory system that retains data even after power is removed from the system. Typically, non-volatile memory is also random access memory, although this is not required.

[0261] While FIG. 60 illustrates the non-volatile memory as a local device directly coupled to the remaining components in the data processing system, the present invention may also utilize non-volatile memory remote from the system, such as a network storage device connected to the data processing system through a network interface, such as a modem or Ethernet interface. Bus 6002 may include one or more buses connected to each other through various bridges, controllers, and / or adapters, as is known in the art. In one embodiment, I / O controller 6009 includes a USB (Universal Serial Bus) adapter for controlling USB peripherals. Alternatively, I / O controller 6009 may include an IEEE-1394 adapter, also known as a FireWire adapter, for controlling FireWire devices.

[0262] Some portions of the preceding detailed descriptions have been presented in terms of algorithms and symbolic representations of operations on data bits within a computer memory. These algorithmic descriptions and representations are the means used by those skilled in the data processing arts to most effectively convey the substance of their work to others skilled in the art. An algorithm is here, and generally, conceived to be a self-consistent sequence of operations leading to a desired result. Operations are those requiring physical manipulations of physical quantities.

[0263] It should be borne in mind, however, that all of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities. Unless otherwise specified as is clear from the above discussion, throughout the description, discussions using terms such as those set forth in the claims that follow will be understood to refer to actions and processes of a computer system or similar electronic computing device that manipulate and transform data represented as physical (electronic) quantities in the registers and memory of the computer system into other data that are similarly represented as physical quantities in the memory or registers of the computer system.

[0264] The techniques shown in the figures may be implemented using code and data stored and executed on one or more electronic devices that use computer-readable media to store and communicate (internally and / or with other electronic devices over a network) the code and data, such as non-transitory computer-readable storage media (e.g., magnetic disks, optical disks, random access memory, read-only memory, flash memory devices, phase-change memory), and transitory computer-readable transmission media (e.g., electrical signals such as carrier waves, infrared signals, digital signals, optical signals, acoustic signals, or other forms of propagated signals).

[0265] The processes or methods illustrated in the previous figures may be performed by processing logic comprising hardware (e.g., circuitry, dedicated logic, etc.), firmware, software (e.g., embodied on a non-transitory computer-readable medium), or a combination of both. While the processes or methods are described above with respect to some sequential operations, it should be understood that some of the described operations may be performed in a different order. Furthermore, some operations may be performed in parallel rather than sequentially.

[0266] Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the medical field. While specific methods, devices, and materials are described in this application, any methods and materials similar or equivalent to those described herein can be used in the practice of the present invention. While embodiments of the present invention have been described in some detail and by way of example, such example is for clarity of understanding only and is not intended to be limiting. In the detailed description of the invention, various terms are used to convey an understanding of the invention; it will be understood that the meaning of these various terms extends to common linguistic or grammatical variations thereof. Furthermore, while some theoretical considerations may have been advanced to facilitate understanding of the technology, the appended claims of the present invention are not bound by such theories. Furthermore, any one or more features of any embodiment of the present invention can be combined with any one or more other features of any other embodiment of the present invention without departing from the scope of the present invention. Furthermore, it should be understood that the present invention is not limited to the embodiments set forth for illustrative purposes, but is defined solely by the fair interpretation of the claims appended hereto, including the full range of equivalents to which each element is entitled.

[0267] Some embodiments of the sensing Foley catheter system include using UV light, or light of an appropriate wavelength, to sterilize the collection chamber itself or other components of the system. The UV light source can direct UV light through the wall of the collection chamber, or the UV light source can be located inside the collection chamber. The UV light source can be used to sterilize the collection chamber when the chamber is empty, full, or partially full. The UV light source can be used to sterilize urine as it enters the collection chamber. The UV sterilization process can occur continuously or intermittently. The UV light source can be located anywhere within the sensing Foley catheter system. Ultraviolet light or other wavelengths of light may be used within the bladder.

[0268] Spectroscopy - Spectrophotometry

[0269] Some embodiments of the sensing Foley catheter system include using light wavelengths ranging from about 520 nm to about 650 nm to distinguish between bacteria, red blood cells, and / or plasma / white blood cells. See the area inside the ellipse in FIG. 61.

[0270] Some embodiments of the sensing Foley catheter system include a combination of spectrophotometry to identify white blood cells and bacteria, and to identify decreased PO2 and / or increased CO2 to identify infection.

[0271] Some embodiments of the sensing Foley catheter system include a controller that filters urine output data to compensate for increased urine output immediately following administration of a diuretic. Urine volume generally increases immediately following administration of a diuretic. However, in certain situations, it may be beneficial to essentially ignore increased urine output data associated with diuretic administration. The controller of the sensing Foley catheter system can automatically ignore urine output data associated with diuretic administration by identifying the shape of the urine output curve associated with diuretic administration and subtracting and / or ignoring data associated with this increase. Identification of the curve shape may be performed by slope, length of increase, amplitude, shape, etc. Subtraction of diuretic-induced urine output data is useful for determining or predicting the onset of AKI. See FIG. 62. For example, if urine volume exceeds approximately 2,000 mL / hour (peak), the controller can identify this as a situation in which a diuretic has been administered.

[0272] Increases in urine output caused by the administration of a diuretic can be distinguished from increases in urine output caused by clamping or otherwise blocking the urinary drainage tube and / or Foley catheter. In situations where the drainage lumen is fixed, the urine output before the increase is essentially zero or very low, e.g., less than 5 mL / hour. In contrast, in situations where a diuretic is administered, the urine output immediately prior to the administration of the diuretic may be very low but is likely to exceed zero, e.g., greater than about 5 mL / hour. Additionally, in situations where the drainage lumen is fixed, the increase in urine output after the drainage lumen is released is of relatively short duration, e.g., from about 30 seconds to about 5 minutes. In contrast, in situations where a diuretic is administered, the increase in urine output is of longer duration, e.g., from about 30 minutes to about 2 hours. Furthermore, in situations where the drainage lumen is fixed, the urine output after the drainage lumen is released may be less than about 1000 mL. In contrast, in a situation where a diuretic is administered, the urine output after administration of the diuretic may exceed approximately 1000 mL. Any or all of these factors can be used by the controller to analyze the urine output over time curve to determine when a diuretic is administered and to subtract the increased urine output due to the diuretic from the urine output presented to the user.

[0273] In this way, the controller can automatically determine when a diuretic is administered. Alternatively, the controller's user interface may include a button or other user input device (e.g., touch screen, voice control) that indicates that a diuretic has been administered. The controller then looks for increased urine volume and subtracts the increased urine volume due to the diuretic from the urine volume data presented to the user.

[0274] Some embodiments of the sensing Foley catheter system include a controller that determines abdominal perfusion pressure (APP). APP is defined as the difference between mean arterial pressure and intraperitoneal pressure (IAP). Mean arterial pressure can be determined by conventional methods and, in combination with the IAP determining controller, can determine APP. The controller can further automatically modify fluid and / or vasopressor / vasopressor infusion to increase or decrease blood pressure.

[0275] Prevents filters / vents from getting wet

[0276] Some embodiments of the sensing Foley catheter system include one or more vents and / or filters to prevent negative pressure from building up within the Foley catheter and causing suction trauma to the bladder. The filter / vent can be located anywhere, such as at the junction of the Foley catheter and the drainage tubing, or within the collection reservoir, or within the lumen of the drainage tubing or Foley catheter itself, as described below.

[0277] The filter / vent in some embodiments is designed to repel fluids, i.e., made from a hydrophobic material. However, despite the use of a hydrophobic material, the filter / vent may still be susceptible to wetting by liquids, especially urine. Some embodiments include a larger lumen, or lumen area, where the filter / vent is positioned to reduce the likelihood of the lumen filling with fluid due to the surface tension of the fluid. FIG. 63A shows a smaller diameter lumen, while FIG. 63B shows a larger diameter lumen in the vent / filter area. Note that if the vent / filter 6304 is facing upward or outward, even a small lumen can allow fluid 6202 to wet the filter / vent, while a larger lumen can reduce the likelihood of wetting the filter / vent.

[0278] In embodiments where the filter / vent is located at or near the junction of the Foley catheter and the drainage tubing, the area below or near the filter / vent can be taped to the patient's leg to stabilize the Foley catheter once it is in place. Larger lumen tubing helps prevent the filter / vent from getting wet in this situation, especially if the vent / filter is facing away from the leg, i.e., away from the patient. In some embodiments, the vent barb may be designed so that the vent / filter faces outward when the barb or barb area is taped to the patient's leg. For example, the barb may be curved or attached to a curved base to better attach and orient it to the patient's leg 6402, as shown in FIG. 64 .

[0279] In some embodiments, the barb area is extended, for example, 6-12 inches, to move the vent / filter further away from the patient and facilitate placement of the vent / filter in a location and manner that prevents it from getting wet.

[0280] In some embodiments, the vent / filter may be located at multiple positions around the diameter of the drainage lumen, within the barb or elsewhere. Alternatively, the vent may surround all or most of the circumference of the lumen. In these embodiments, a reinforcing cuff or other structure may surround the vent to provide structural integrity to the lumen. Filter / vents may also be located along the length of the drainage tube.

[0281] The embodiment shown in Fig. 65 also prevents wetting of the vent / filter. This embodiment includes a vent tube 6502 with an inner lumen that connects to a drainage lumen 6504 near the barb area 6506 and is vented to atmosphere or other air / gas / fluid through one or more filter / vents 6508 along the vent tube and / or near the other end. The filter / vent may be within the collection reservoir as shown in Fig. 65, separate from the collection reservoir, etc.

[0282] The drainage lumen may be incorporated into the drainage lumen, either alongside or within the urinary drainage lumen. Alternatively, the vent lumen may be separate from the drainage lumen and connected to the drainage lumen near the vent / drainage tube junction, e.g., near the barb region 6506.

[0283] 66 shows a sensing Foley catheter system having a positive pressure vent tube 6602 with an inner lumen in fluid communication with a urinary drainage lumen 6604 and a pump 6606. The positive pressure vent tube may include a filter 6612 anywhere along its length, in-line or otherwise. The positive pressure vent tube may include a vent hole at either end of the tube, anywhere along the tube, or may include multiple vent holes.

[0284] Instead of applying negative pressure to the urinary drainage lumen and pumping positive pressure to atmosphere, the positive pressure is pumped back to the urinary drainage lumen via the positive pressure tubing. Alternatively, different pumps can be used for negative and positive pressure. In this manner, a precise negative or positive pressure can be controlled at the junction 6608 of the urinary drainage lumen and the positive pressure vent tubing. Preferably, the pressure within the junction 6608 is either slightly negative or neutral to prevent fluid flow back into the Foley catheter. For example, the pressure at the junction is maintained at approximately 0 mmHg. Alternatively, the pressure at the junction can be maintained at approximately -2 mmHg. An optional regulator 6610 can control the negative pressure relative to the positive pressure through magnitude, timing, etc. For example, the regulator (controlled by the controller) may implement a slight delay to first apply negative pressure to the urinary drainage line, and then after a set time, or once a certain negative pressure has been achieved, positive pressure is applied to the positive pressure tubing, eventually reaching the positive pressure tubing / drainage tubing junction. This results in a positive net pressure at the positive pressure tubing / drainage tubing junction, preventing urine from flowing into the bladder rather than out of it. Any regulator can take the form of a vent with specific dimensions (small surface area or tight filter material for low resistance, large surface area or loose filter material for low resistance). The positive pressure vent tube can be connected to the urinary drainage lumen through a valve, such as an umbrella valve, with a set cracking pressure.

[0285] Alternatively, the positive pressure tube may be pressurized with compressed sterile fluid / gas / air.

[0286] Furthermore, precise control of the negative pressure applied to the bladder can allow for replication of the normal filling and draining of the bladder. For example, a neutral or zero pressure can be maintained, or a slight positive pressure can be maintained at the base of the Foley for a period of time to allow the bladder to fill normally. Then, after a set period of time or after a specific pressure (i.e., the pressure required to maintain neutral pressure at the base of the Foley catheter) is reached, the pressure can be reduced to empty or drain the bladder. This process is controlled by a controller that controls the pressure regulator, and the process is repeated to mimic the normal filling and draining of the bladder.

[0287] In some embodiments, a valve may be used at the base of the Foley catheter to better control pressure in that area, including pressure (negative or positive) on the bladder.

[0288] It should be noted that the positive pressure tubing embodiments can be used with any of the sensing Foley catheter system embodiments, including those with different filter / vent configurations than those shown herein. Additionally, any of the airlock prevention embodiments can be used with regular, i.e., non-sensing, Foley catheters, or other catheters or drainage tubing.

[0289] 67-86 show enlarged views of barb region X of FIG. 66 to illustrate different example embodiments of this region.

[0290] In the embodiment shown in FIG. 67, a valve 6702, such as an umbrella valve, having a set cracking pressure is shown between the lumen of the positive pressure vent tube 6602 and the urinary drainage lumen 6604. The valve may be a one-way valve. A vent 6704 is shown between the positive pressure vent tube and atmosphere. In some configurations, only a vent or only a valve is present. An opening 6706 is in fluid communication with the urinary drainage lumen 6604 and a chamber 6714 (the valve 6702 periodically blocks fluid communication to the chamber). The chamber 6714 is in fluid communication with the lumen of the positive pressure vent tube 6602. Periodically or continuously, positive pressure is applied through the positive pressure lumen 6702 and / or negative pressure is applied to the urinary drainage lumen 6604, above which fluid, preferably gas, flows through the valve 6702, opening 6706, and the lumen of the urinary drainage lumen 6604. This can clear the line of airlocks or blockages and clear fluid from the chamber 6714, thereby reducing the chance of wetting the vent 6704. It can also help clear the vent 6704 if it becomes wet. The cracking pressure of the valve 6702 refers to the pressure difference between the positive pressure lumen 6702 and the urinary drainage lumen 6604. When the pressure in the urinary drainage lumen is lower than the pressure in the positive pressure lumen due to the cracking pressure, the valve opens, allowing fluid to flow from the positive pressure lumen, through the chamber, through the opening 6706, and through the drainage lumen. For example, the cracking pressure can be less than about 1 mmHg. Alternatively, the cracking pressure can be less than about 2 mmHg. Alternatively, the cracking pressure can be less than about 3 mmHg. Alternatively, the cracking pressure can be less than about 4 mmHg. Alternatively, the cracking pressure can be less than about 5 mmHg. Alternatively, the cracking pressure can be less than about 10 mmHg.

[0291] The pressure in the urinary drainage lumen may be periodically or continuously about -5 mmHg. Alternatively, the pressure in the urinary drainage lumen may be periodically or continuously about -7 mmHg. Alternatively, the pressure in the urinary drainage lumen may be periodically or continuously about -10 mmHg. Alternatively, the pressure in the urinary drainage lumen may be periodically or continuously about -15 mmHg. Alternatively, the pressure in the urinary drainage lumen may be periodically or continuously about -20 mmHg. Alternatively, the pressure in the urinary drainage lumen may be periodically or continuously about -25 mmHg. Alternatively, the pressure in the urinary drainage lumen may be periodically or continuously about -30 mmHg.

[0292] The positive pressure in the positive pressure lumen may be periodically or continuously about 5 mmHg. Alternatively, the positive pressure in the positive pressure lumen may be periodically or continuously about 7 mmHg. Alternatively, the positive pressure in the positive pressure lumen may be periodically or continuously about 10 mmHg. Alternatively, the positive pressure in the positive pressure lumen may be periodically or continuously about 15 mmHg. Alternatively, the positive pressure in the positive pressure lumen may be periodically or continuously about 20 mmHg. Alternatively, the positive pressure in the positive pressure lumen may be periodically or continuously about 25 mmHg. Alternatively, the positive pressure in the positive pressure lumen may be periodically or continuously about 30 mmHg.

[0293] A vent may also, or alternatively, be present elsewhere along the positive pressure vent line, such as near the pump or as part of a pressure regulator. A second vent / valve assembly 6708 is shown at the barb in FIG. 67, although this second vent / valve assembly may or may not be present. An optional thermistor 6710 and optional pressure lumen 6712 are also shown. Alternatively, the positive pressure vent line may be exposed to atmospheric pressure. The valve, or additional valves, may be present anywhere in the system, such as in the positive pressure tubing 6602 or in the reservoir.

[0294] FIG. 68 illustrates an embodiment of a barb region including a vent 6802, a valve 6804, and a cross-sectional area 6806 large enough to allow free flow of air / gas from the vent to the urinary drainage lumen, but small enough to prevent the flow of liquids into the vent. For example, the constricted portion 6806 may be less than about 1 mm in diameter. Alternatively, the constricted portion may be less than about 2 mm in diameter. Alternatively, the constricted portion may be less than about 3 mm in diameter. Alternatively, the constricted portion may be less than about 4 mm in diameter. The length of the constricted portion is about 1-5 mm. Alternatively, the constricted portion may be about 5-30 mm in length. The embodiment illustrated in FIG. 68 may or may not include a positive pressure tube and is shown without the positive pressure tube (i.e., exposed to atmosphere). This embodiment may or may not include a valve. This and any of the embodiments may be incorporated into the barb, or may be a separate component that can be added to the barb (via a sampling or other port) or elsewhere in the system (e.g., along the drainage tube, preferably in the 1 / 3 of the drainage tube closest to the patient).

[0295] FIG. 69 illustrates an embodiment of a barb region including a vent 6902 and a long vent tube 6904 that is long enough to allow free flow of air / gas from the vent to the urinary drainage lumen but prevent the flow of liquids into the vent. For example, the vent tube portion 6904 may be approximately 1-10 mm in diameter and approximately 1-10 cm in length. For example, the vent tube portion 6904 may be greater than approximately 2 cm in length. Alternatively, the vent tube portion 6904 may be greater than approximately 4 cm in length. Alternatively, the vent tube portion 6904 may be greater than approximately 10 cm in length. The embodiment illustrated in FIG. 69 may or may not include a positive pressure tube and is shown without the positive pressure tube. This embodiment may or may not include a valve.

[0296] FIG. 70 shows an embodiment of a barb region that includes a vent 7002 and a long, serpentine vent tube 7004 that allows free flow of air / gas from the vent to the urinary drainage lumen, but is tortuous enough to prevent the flow of liquids into the vent. For example, the vent tube portion 7004 may be a coil. The embodiment shown in FIG. 70 may or may not include a positive pressure tube, and is shown without the positive pressure tube. This embodiment may or may not include a valve.

[0297] FIG. 71 shows an embodiment of a barb region that includes a vent 7102 and a simple serpentine vent tube 7104 that allows free flow of air / gas from the vent to the urinary drainage lumen, but is tortuous enough to prevent the flow of liquids into the vent. For example, the vent tube portion 7104 can be a tube with a baffle or mesh in the lumen. The embodiment shown in FIG. 71 may or may not include a positive pressure tube, and is shown without the positive pressure tube. This embodiment may or may not include a valve.

[0298] FIG. 72 shows an embodiment of a barbed region including a vent hole 7202 and a vent tube 7204. In this embodiment, the vent tube is in fluid communication with a positive pressure tubing 7206, and the vent hole 7202 is aligned with the positive pressure lumen, so that fluid under positive pressure passes through the vent hole via opening 7208, through the vent tube, and into the drainage lumen. The vent tube 7204 is shown coiled here to prevent backflow of urine into the vent tube, but the vent tube 7204 may be any configuration, including a straight tube or a lumen integrated into the barbed region. Here, the vent hole 7202 is shown near the junction of the vent tube 7204 and the positive pressure tubing 7206, but the vent may be anywhere along the positive pressure lumen, including near the pump / cassette or near the opening to the drainage lumen 7208. This embodiment may or may not include a valve.

[0299] 73A and 73B illustrate an embodiment of a barbed region including a vent 7302 and a simple, serpentine vent tube 7304 that allows free flow of air / gas from the vent to the urinary drainage lumen, but is sufficiently tortuous to prevent the flow of liquids into the vent. Additionally, the vent end of the vent tube 7304 can be configurable, bendable, or deformable so that it faces upward after the barbed region is secured to the patient's leg. Facing the vent end of the vent tube upward reduces the likelihood of the vent coming into contact with liquids. For example, the vent tube portion 7304 can be essentially a flat coil. The embodiment shown in FIG. 73 may or may not include a positive pressure tube—it is shown without the positive pressure tube. This embodiment may or may not include a valve 7306.

[0300] FIG. 74 illustrates an embodiment of a barb region including multiple vent holes 7402 and an optional valve 7404. Multiple vent holes reduce the chance of all vent holes becoming wet with urine. The multiple vent holes may be in any suitable configuration, including a line, a circle, or the like. The multiple vent holes may be on one side of the barb, or may partially or completely surround the barb. For example, two vent holes may be included, or three vent holes may be included, or four vent holes may be included, or five vent holes may be included, or six vent holes may be included, or seven vent holes may be included, or eight vent holes may be included, or nine vent holes may be included, or ten vent holes may be included. The embodiment illustrated in FIG. 74 may or may not include a positive pressure tube and is shown without the positive pressure tube. This embodiment may or may not include a valve.

[0301] FIG. 75A shows an embodiment of the barb region that does not rely on a vent, although it may still include one or more vents. In this embodiment, a positive pressure tube 7502 is in fluid communication with a urinary drainage lumen via an opening 7504. Additionally, a valve, preferably a pressure-sensitive valve 7506, is between the opening 7504 and the drainage catheter and is in fluid communication with a positive pressure source via an opening 7510. The valve 7506 is depicted in FIG. 75A as an inflatable valve, such as an annular balloon (also shown in FIG. 75B). The valve 7506 may be inflated via the same pressure source connected to the positive pressure tube 7502 or a separate source. The valve 7506 may be in fluid communication with the lumen of the positive pressure tube 7502 as shown here, or may be inflated via a separate positive pressure lumen.

[0302] In this embodiment, positive pressure is periodically applied to the drainage lumen via positive pressure tubing 7502, causing valve 7506 to close. This prevents air or positive pressure from reaching the bladder and purges the drainage lumen allowing positive pressure fluid (gas or liquid) to flow. When the positive pressure in the positive pressure tubing is reduced, the valve opens and urine is again allowed to drain from the bladder. A slight positive pressure can be maintained in the positive pressure tubing to offset the negative pressure in the urinary drainage line. If higher pressure is needed to clear the line of the airlock, valve 7506 is closed during a higher pressure flush.

[0303] Figure 76 shows an embodiment similar to that shown in Figure 75, but in this embodiment, the valve 7602 is a passive mechanical valve. The valve 7602 is normally in a flat or open position. When the positive pressure in the positive pressure tubing is higher than the negative pressure in the drainage lumen, the valve automatically closes, preventing fluid / positive pressure from being transmitted to the patient's Foley catheter / bladder.

[0304] Alternatively, a venturi can be used to control the negative and positive pressures exuding into the barb area, similar to an automobile carburetor.

[0305] 77A and B show another embodiment that uses a more active valve system, including a suction chamber 7702, a compliant portion 7704, a patient-side valve 7706, a drainage-side valve 7708, a drainage lumen inlet 7710, and pressure lines 7712, 7714, 7716, 7718.

[0306] In the passive, or open, position, both the patient-side valve 7706 and the drainage-side valve 7708 are open, i.e., the balloon / bladder is not inflated, allowing urine to pass freely from the drainage catheter 7722, through the drainage lumen 7720 of the barb, and through the drainage tubing 7724. In the open position, the compliant portion 7704 is in a neutral position. In the event of an obstruction vent, such as an airlock, or to periodically prevent obstruction, the drainage line valve 7708 is closed by applying pressure, such as pressurized fluid (gas or liquid), via pressure line 7716. The compliant portion 7704 is expanded by applying negative pressure via pressure line 7718. The pressure line 7714 remains neutral, or closed. The pressure line 7712 remains neutral, or closed, or negative, to fully contract the valve 7706. This configuration effectively applies negative pressure to the drainage catheter by expanding the compliant portion 7704 while blocking fluid flow to the drainage line 7724. This configuration is shown in Figure 77A.

[0307] The configuration of FIG. 77A lasts only a short time, for example, about 0.5-1 second, or about 1-3 seconds, or about 3-5 seconds. Next, the patient-side valve 7706 is closed by applying positive pressure to pressure line 7712, and the drainage-side valve is opened by either reducing the pressure in pressure line 7716 to neutral or applying negative pressure to pressure line 7716. The pressure in pressure line 7718 is increased to neutral or decreased by applying positive pressure to pressure line 7718. Positive pressure can also be applied to pressure line 7714. This configuration is shown in FIG. 77B. In this configuration, fluid within drainage lumen 7720 and drainage line 7724 is flushed with fluid (gas / liquid) via pressure line 7714 and / or by the positive pressure applied by the reduced volume of compliant portion 7704, effectively flushing urine through the drainage line. After flushing, the system is returned to the neutral position, with the patient-side valve 7706 and the drainage-side valve 7708 both open and the compliant portion 7704 in the neutral position.

[0308] FIG. 78 shows an embodiment similar to that shown in FIG. 72, but with a positive pressure vent tube 7802 rather than a separate vent tube. A vent hole 7804 is in fluid communication with and coincides with the lumen of the positive pressure vent tube 7802. The vent hole 7804 is also in fluid communication with the barbed region 7808 of the urinary drainage lumen and is connected to region 7808 by an opening 7806. Fluid / air / gas under positive pressure passes through the vent hole 7804 and through the opening 7806 into region 7808, which is in fluid communication with the drainage lumen. That is, the fluid / air / gas under positive pressure passes through a filter to reach the inside of the barb. Wetting of the vent hole 7804 is prevented by controlling the positive pressure across the vent hole 7804 within the positive pressure tube, as well as the negative pressure in the drainage lumen. In some embodiments, the pressure within the barbed region 7808 of the urinary drainage lumen is near zero. The vent 7804 may be located anywhere along the length of the positive pressure vent tube 7802. The embodiment shown in FIG. 78 may or may not include a one-way valve between the filter and the opening. The positively pressurized fluid / air / gas may be passed through the vent continuously, intermittently, or sporadically. The positively pressurized fluid / air / gas may pass through the vent in streams, puffs, or pulses.

[0309] Filters throughout the system, whether in barbs, positive pressure tubes, ventilation tubes, reservoirs, or elsewhere, may be cleared using pressure. For example, a puff of pressurized air or gas may be applied across the filters to clear or dry them if they are wet. Alternatively, a steady or intermittent flow of air or gas may be used.

[0310] FIG. 79 shows an embodiment in which the area within the barb that is in fluid communication with the urinary drainage lumen has a larger volume. Fluid 2902, such as urine, flows from the drainage catheter into a large reservoir 7904 and then into the urinary drainage lumen. The reservoir 7904 is large enough that it rarely fills completely with liquid. The volume of the reservoir that is not filled with liquid is filled with air or gas. A one-way valve 7908 may also be present. Because there is always some air / gas in the reservoir 7904, the vent 7906 can be positioned so that it has little contact with the urine / fluid in the reservoir. That is, the vent may be on the side of the air bubble in the reservoir. There may be multiple vents to ensure that at least one vent is always in fluid communication with the air bubble in the reservoir. In some embodiments, the volume of the reservoir 7904 may be larger than the volume of the lumen of the drainage tube.

[0311] 80A and 80B show embodiments with very large vent areas. While the vent 8002 is shown here as a large, flat circle or disk, the vent can be any shape and size. The vent can be flat or curved, wrapping around the barb area. While the embodiment shown here is with one opening 8004 and one-way valve 8006, other embodiments may have two or more openings, with or without a valve. Some embodiments may have a filter surface greater than about 1 cm. Some embodiments may have a filter surface greater than about 2 cm. Some embodiments may have a filter surface of about 3 to about 4 cm. Alternatively, some embodiments may have a filter surface of about 2 to about 4 cm. Alternatively, some embodiments may have a filter surface of about 4 to about 6 cm. Alternatively, some embodiments may have a filter surface of about 6 to about 10 cm.

[0312] FIG. 81 illustrates an embodiment with a replaceable vent. Here, the replaceable vent 8102 is shown in an embodiment with a positive pressure tube 8104 and a one-way valve 8106, although embodiments without the positive pressure tube and / or valve are also possible. The replaceable vent 8102 can be removed and replaced via an attachment mechanism such as a luer lock, snap lock, slide-in lock, press-fit, or other suitable mechanism. Vent replacement can be performed periodically, such as once a day, or as needed (e.g., when the controller alerts the user that the vent is no longer functioning properly or when the user notices that the vent is no longer functioning). The vent contains a chemical that is sensitive to urine or urine components and changes color to indicate wetness. For example, a pH-sensitive or other chemical or attribute-sensitive paper can be used in the replaceable vent to change color and be visible to the user. The replaceable vent is disposable.

[0313] FIGS. 82A and 82B show an embodiment in which the filter is flexible. In this embodiment, the filter 8202 may be flexible or deformable, i.e., it may be convex / concave or loose within its housing. The movement of the flexible filter 8202 helps to unclog the filter if it becomes wet or contaminated. The movement of the filter can be controlled by positive pressure via the positive pressure tubing 8204, negative pressure via the urinary drainage lumen, a valve 8206, or any single or combination of the above. Some embodiments may also include a mechanical mechanism to agitate, shake, vibrate, bend, and / or move the filter 8202. For example, FIG. 82A shows an example embodiment in which negative pressure in the urinary drainage lumen causes the filter to become concave. FIG. 82B shows the same example after positive pressure is applied to the vent via the positive pressure tubing 8204. The pressure within the vent housing 8208 can be controlled by the cracking pressure of a one-way valve or the relative negative and positive pressures within the urinary drainage lumen and positive pressure tubing. There can also be similar embodiments in which the filter is not flexible, but the pressure within the vent housing 8208 is controlled in a similar manner that keeps the filter dry.

[0314] Alternatively, the filter (flexible or otherwise) may be mechanically wiped or scraped, either manually or automatically. Alternatively, the filter may contain chemicals that inhibit protein adhesion and / or accumulation, such as enzymatic detergents. Alternatively, the filter may contain chemicals that inhibit biofilms, such as antibacterial agents.

[0315] FIG. 83 illustrates an embodiment with multiple stacked filters. Filters of different pore sizes can be stacked. For example, a coarse-pore filter 8304 may protect the fine-pore filter 8302 from getting wet. The coarse-pore filter 8304 can be placed between the fluid / urine and the fine-pore filter 8302. In this configuration, the fluid / urine must pass through the coarse filter 8302 to contact the fine filter 8302. Two or more filters can be stacked in this manner. They may have graduated pore sizes, similar pore sizes, or any pore size. For example, increasingly fine-pore filters may be stacked so that the finer pore filters are further from the urine / liquid. Alternatively, one or more coarse-pore filters of the same or different pore sizes may be placed between the urine / liquid and the fine-pore filter. A one-way valve may or may not be present. The pore size of the coarse-pore filter 8304 may be approximately 10 microns. Alternatively, the pore size of the coarse-pore filter 8304 may be from about 10 to about 20 microns. Alternatively, the pore size of the coarse pore filter 8304 may be from about 10 to about 30 microns.

[0316] FIG. 84 illustrates an embodiment in which a continuous positive pressure is applied to the barb area by fluid in a positive pressure tube. The positive pressure tube is under a nearly constant positive pressure, and fluid (preferably air / gas) is continuously passed through the opening 8404. The positive pressure applied to the fluid in the interior 8406 of the barb is controlled to prevent backflow of the fluid into the urinary drainage catheter. That is, the negative pressure applied to the fluid in the interior 8406 is always greater than or approximately equal to the positive pressure applied to the fluid in the interior 8406. The positive pressure may be controlled by a controller and / or by the size of the opening 8404, for example, by making the size of the opening 8404 very small. For example, the diameter of the opening 8404 may be less than about 1 mm. Alternatively, the diameter of the opening 8404 may be less than about 2 mm. Alternatively, the diameter of the opening 8404 may be less than about 3 mm. Alternatively, the diameter of the opening 8404 may be less than about 4 mm.

[0317] FIG. 85 shows an embodiment with an accordion-shaped vent. The vent 8502 in this embodiment is shaped like an accordion. The vent may be compressed in the direction of the double-headed arrow. This compression can clear blockages / wetness etc. from the vent. Compression can be done manually, automatically / mechanically, and / or using pressure (negative and / or positive) within the vent area.

[0318] FIG. 86 shows an embodiment with a single vent and multiple openings. In this embodiment, multiple small openings 8602 separate the urinary drainage lumen from the vent 8604. The small openings prevent fluid from contacting the vent 8604. Multiple openings can act as redundancy, so if one or more openings become clogged, the others remain open. The openings can also be used to control the passage of air / gas / fluids through the vent 8604; more holes provide less resistance to airflow, and fewer holes provide more resistance to airflow.

[0319] Any of the embodiments herein may include physiological pressure measurement or may be used without physiological pressure measurement. For example, the systems shown in Figures 1 and 2, Figures 67-86, and other embodiments may not include a thermistor or pressure lumen and may be used with a standard Foley catheter.

[0320] In some embodiments, pressure may be measured at the positive pressure tubing / drainage tubing junction. Alternatively, pressure may be measured at the sensing Foley catheter / drainage tubing junction or at the barb area. Pressure can be measured at any of these locations by incorporating an additional tube or lumen that is in fluid communication with the pressure tubing / drainage tubing junction or the barb area at one end and in fluid communication with a pressure sensor or transducer at the other end. For example, this pressure measurement lumen may be in fluid communication with a controller housing a pressure sensor at one end (the sensor end) and in fluid communication with the positive pressure tubing / drainage tubing junction at the other end (the sensing end). A pressure-sensitive membrane may be present at the sensing end to prevent urine contamination of the lumen.

[0321] Airlocks may also be detected so that they can be optimally removed and / or avoided. Using any of the embodiments herein, the controller may apply a slight positive or negative pressure to the urinary drainage lumen and sense the response. A dampened response may indicate the presence of an airlock, while a less dampened response indicates less airlock, as air is more compressible than urine. If excessive airlocks are detected, the controller can initiate airlock clearing, for example, by applying negative pressure to the drainage lumen.

[0322] In some embodiments, the valve may be located anywhere in the system, including in the positive pressure line or in the reservoir.

[0323] The vent tube may be a separate tube from the drainage tube, or may be inserted within the drainage lumen or even the Foley catheter. FIG. 87 shows an embodiment of a sensing Foley catheter system in which the vent tube is inside the urinary drainage tube. This type of embodiment has the advantage of being usable with any standard drainage tube. The vent tube places the vent either within the drainage lumen, the drainage tube, or the Foley catheter. The vent tube may be slidably inserted within the drainage tube and / or Foley catheter and may be moved at any time.

[0324] In the embodiment shown in FIG. 87 , the vent tube 8704 opens at one end (the "air end" 8708) to a vent / filter 8702 in the collection reservoir (which is open to atmospheric pressure) and at the other end (the "urine end" 8710) within the drainage lumen 8706. While the vent tube is shown here terminating within a barb at the base of the Foley catheter, it can terminate anywhere within the urinary drainage lumen, including within the drainage tube or anywhere within the Foley catheter. The vent tube can remain in one location or move within the system to maximize urine drainage and minimize damage to the bladder due to airlock and negative pressure within the bladder.

[0325] FIG. 88 shows another embodiment of a sensing Foley catheter system in which a vent tube 8802 has a vent / filter 8804 at the "urine end" of the tube and is open to atmosphere at the "air end" 8806 of the tube. There may also be filters / vents at both ends. The "air end" of the vent tube can exit the drainage lumen via a Y-arm adapter, stopcock, or other standard method. The "air end" of the vent tube can exit the system from within the collection reservoir via a channel or port built into the collection reservoir. Again, the vent tube can be used with any urinary drainage tube, including standard urinary drainage tubes.

[0326] FIG. 89 shows an embodiment similar to that shown in FIG. 88 with the addition of a positive pressure tube 8902.

[0327] Figures 90 and 91A and 91B show the vent tube in different positions within the sensing Foley catheter system. In Figure 90, the "urinary end" 9002 of the vent tube is only partially within the drainage tube. For example, the vent tube may be inserted through approximately half of the drainage tube. Or, for example, the vent tube may be inserted through approximately one-third of the drainage tube. Or, for example, the vent tube is inserted approximately two-thirds of the way down the drainage tube. In Figure 91A, the "urinary end" 9002 of the vent tube is within the Foley catheter. The location of the "urinary end" of the vent tube is determined based on maximizing urine drainage, minimizing the effect of airlock on drainage, and minimizing negative pressure within the bladder. In Figure 91B, the vent tube is inside the drainage tube, connecting at one end at or near the barb and terminating approximately 6 to 24 inches into the drainage line. The vent tube may or may not include a filter or valve.

[0328] In some embodiments, after an initial volume of urine has been drained from the bladder, a vent tube is attached to the sensing Foley catheter system.

[0329] The vent tube can incorporate one or more filters / vents. The vent tube can incorporate one or more cutouts that are in fluid communication with the lumen of the vent tube and ultimately in fluid communication with a vent / filter at a collection reservoir or elsewhere. Multiple filters / vents or multiple cutouts can be located around the vent tube, along the vent tube, or both. The vent tube may also include a filter, a "pee end," or ultraviolet light directed elsewhere to maintain sterility.

[0330] 92A and 92B show some possible embodiments of a drainage lumen, such as the drainage lumen 1012 shown in FIG. 10A. FIG. 92A shows a drainage lumen with a collapsible / expandable portion 9202. Portion 9202 is made from a lower durometer material than the rest of the drainage lumen and collapses and expands depending on the internal pressure. The lumen collapses to a lower internal area / volume at low or negative pressure and expands at higher or positive pressure. Airlock may be reduced due to this change in lumen volume at different pressures. This type of lumen can be incorporated into any of the embodiments herein.

[0331] FIG. 92B shows an embodiment of a drainage lumen that includes two lumens. The inner lumen shown here is a negative pressure / urinary drainage lumen 9204. The outer lumen is a positive pressure lumen 9206. Between the two lumens is an opening 9208. The opening may or may not include a filter membrane. The two lumens may be concentric, as shown here, or adjacent. The positive pressure lumen serves essentially the same purpose as the positive pressure vent tube shown elsewhere herein. As negative pressure acts on the drainage lumen 9204, resulting in clearance of the drainage lumen 9204, positive pressure is constantly or periodically applied to the positive pressure lumen 9206.

[0332] Figures 93A through 93E show another embodiment of a drainage lumen. This embodiment also includes a drainage lumen 9302 and a positive pressure lumen 9304. In this embodiment, the positive pressure lumen 9304 is expandable and collapsible. In the expanded state of the positive pressure lumen, it partially or completely blocks the drainage lumen. In the collapsed state of the positive pressure lumen, the drainage lumen is substantially open, allowing fluid to flow freely through the drainage lumen. Figure 93A shows the drainage lumen in a closed state near the patient end of the drainage tube. Figure 93B shows the drainage lumen in a closed state further away from the patient. Figure 93C shows the drainage lumen in an open state.

[0333] FIG. 93D shows a longitudinal view of the drainage tube in a closed state. FIG. 93E shows a longitudinal view of the drainage tube in an open state. As shown in FIGS. 93C and 93E, in the open state, the positive pressure lumen 9304 collapses and does not substantially obstruct the drainage lumen 9302, allowing urine to flow freely from the body to the reservoir. When an airlock or other occlusion clearance of the drainage tube is performed, the positive pressure lumen expands, forcing urine / fluid out of the drainage tube toward the collection reservoir. The patient end 9306 of the positive pressure lumen can be of a larger diameter and / or lower durometer than the reservoir end 9308 of the positive pressure lumen. This allows the patient end of the positive pressure lumen to expand before the reservoir end expands. In this way, the drainage lumen is blocked first closest to the patient, then either nearly all of the drainage lumen is filled, or a portion of the drainage lumen is filled with the remaining inflation of the positive pressure lumen. The positive pressure lumen can be inflated on either the patient or reservoir side of the drainage tube. There may be one or more filters along the length of the drainage lumen.

[0334] Embodiments of the sensing Foley catheter system can include the ability to measure pressure within the bladder via a pressure balloon connected to the Foley catheter or via a pressure balloon or other pressure sensor inserted within the drainage tube or drainage lumen of the Foley catheter. See, e.g., Figures 94A-94C.

[0335] 94A-94C illustrate an embodiment of a sensing Foley catheter system in which the pressure sensor is in fluid communication with the urinary lumen of the Foley catheter, but may be on a separate catheter. A Foley-style catheter 9402 is shown with a urinary lumen 9404 and a urinary drainage opening 9406. A miniature pressure-sensing catheter 9408 with a pressure-sensing balloon 9410 is shown within the urinary drainage lumen of the Foley-style catheter. The outer diameter of the pressure-sensing catheter is small enough to fit within the urinary drainage lumen of the Foley-style catheter. For example, the outer diameter of the pressure-sensing catheter is less than about 4 mm, alternatively the outer diameter of the pressure-sensing catheter is less than about 3 mm, alternatively the outer diameter of the pressure-sensing catheter is less than about 2 mm, or alternatively the outer diameter of the pressure-sensing catheter is less than about 1 mm.

[0336] The pressure sensor on the pressure-sensing catheter may be near the distal end of the pressure-sensing catheter or anywhere along the length of the catheter. The pressure sensor may be a pressure-sensing balloon or any type of pressure sensor, such as a piezoelectric sensor, a mechanical sensor, etc. In the case of a pressure-sensing balloon, the inflated balloon may be smaller than the inner diameter of the urinary drainage lumen of the Foley catheter, or the inflated balloon may be large enough to fill the urinary drainage lumen of the Foley catheter.

[0337] The inflated pressure-sensing balloon can fill the urinary drainage lumen of the Foley catheter, allowing for better pressure measurements. The pressure-sensing balloon can be periodically deflated or partially deflated to allow urine to flow from the bladder through the Foley catheter. Control of the pressure-sensing balloon inflation cycle can be controlled by a controller of the present invention.

[0338] 94B shows an embodiment of a pressure-sensitive catheter having both an occlusion balloon 9424 and a pressure-sensitive balloon 9426. Because the occlusion balloon occludes the urinary drainage lumen, the pressure-sensitive catheter senses only the pressure between the occlusion balloon and the bladder, thereby providing a more precise and accurate measurement of pressure within the bladder.

[0339] The outer diameter of the inflated pressure sensing balloon may be less than about 5 mm, or the outer diameter of the pressure sensing catheter may be less than about 4 mm, or the outer diameter of the pressure sensing catheter may be less than about 3 mm, or the outer diameter of the pressure sensing catheter may be less than about 2 mm, or the outer diameter of the pressure sensing catheter may be less than about 1 mm.

[0340] FIG. 94C shows a standard Foley-style catheter with a retention balloon 9412, a urinary drainage opening 9406, a retention balloon port 9414, and a urinary drainage port 9416. An adapter 9418 is shown connected to the urinary drainage port 9416. The adapter 9418 has two ports: a urinary drainage port 9420 and a secondary urinary lumen port 9422. A pressure-sensing catheter 9408 is shown at the urinary lumen port 9422. In this manner, the pressure-sensing catheter is in fluid communication with the urinary drainage lumen of the Foley-style catheter. The proximal end of the pressure-sensing catheter 9408 is connected to a pressure sensor, such as a pressure transducer, as in other embodiments herein. The pressure-sensing catheter 9408 may have a single lumen, only a sensing balloon lumen, or may include other lumens. If the pressure sensor of the pressure sensing catheter is a mechanical pressure sensor, the pressure sensing catheter may have no lumen, or the pressure sensing catheter may have a balloon to seal the urinary drainage lumen of a Foley-type catheter.

[0341] The pressure sensing catheter may also be inserted through the urinary drainage lumen of the drainage tube.

[0342] A pressure-sensing catheter can be used to obtain pressure measurements over time and analyzed by any of the methods disclosed herein. To improve pressure measurements, the drainage port 9420 can be periodically closed or blocked. Blocking the drainage port 9420 can be done mechanically using a stopcock or valve, or automatically using, for example, a solenoid valve connected to a controller. An advantage of this embodiment is that the pressure-sensing catheter 9408 can be used with any Foley-style catheter to measure pressure. Furthermore, the pressure-sensing catheter 9408 can be inserted and detached from the Foley-style catheter after the Foley-style catheter has already been placed in the patient's bladder.

[0343] The pressure sensing catheter may be combined with a vent tube as shown in other figures. In this manner, the pressure sensing, urinary drainage, anti-airlock, and vent components of the pressure Foley catheter system can be used with standard Foley catheters and drainage tubes. Alternatively, the pressure sensing catheter / vent tube combination may be used with more specialized Foley catheters and / or drainage tubes.

[0344] In any of the embodiments including any type of airlock clearing mechanism, airlock clearing may be performed continuously, periodically (scheduled or ad-hoc), on-demand, or when an airlock condition is detected. The airlock clearing mechanism prevents or mitigates an airlock. For example, the airlock clearing mechanism may reduce the airlock so that the airlock is cleared at least every 60 minutes. Alternatively, the airlock may be cleared at least every 45 minutes. Alternatively, the airlock may be cleared at least every 30 minutes. Alternatively, the airlock may be cleared at least every 20 minutes. Alternatively, the airlock may be cleared at least every 10 minutes. Alternatively, the airlock may be cleared at least every 5 minutes. Alternatively, the airlock may be cleared at least every minute.

[0345] In any of the embodiments that include a vent or filter or vent tube as part of the barb region or drainage tube, liquid (i.e., urine) drainage may be discontinuous or interrupted due to gas / air being introduced into the drainage lumen via the vent / filter / vent tube, i.e., the drainage lumen may alternate between liquid (i.e., urine) and gas.

[0346] In any of the embodiments involving real-time urine output measurements, real-time may mean that the reported urine output measurements are accurate to within about 1 minute. Alternatively, real-time may mean that the reported urine output measurements are accurate to within about 5 minutes. Alternatively, real-time may mean that the reported urine output measurements are accurate to within about 10 minutes. Alternatively, real-time may mean that the reported urine output measurements are accurate to within about 20 minutes. Alternatively, real-time may mean that the reported urine output measurements are accurate to within about 30 minutes. Alternatively, real-time may mean that the reported urine output measurements are accurate to within about 60 minutes.

[0347] Foam in urine - Prevents foam and / or influence on measurements

[0348] Proteins or other components in urine can cause excessive foaming of the urine in the drainage lumen and / or collection container, which can lead to problems with wetting the vent / filter, urine entry, etc. Some embodiments of the Foley catheter system incorporate an anti-bubble mechanism.

[0349] In some embodiments, such as those incorporating positive pressure tubing, precise control of the pressure within the urinary drainage can be obtained. Occasionally, a slight positive pressure can be applied within the drainage system (i.e., the drainage lumen and / or collection chamber) to collapse any air bubbles present or prevent their formation.

[0350] Surfactants such as silicone, simethicone, or other suitable materials may be added to the system. For example, slow-dissolving silicone capsules may be added to the collection reservoir. Alternatively, a surfactant coating may be used on the inside of the drainage lumen and / or the inside of the collection container.

[0351] Air bubbles can be eliminated or reduced at the junction between the drainage tube and the collection container. Some embodiments are shown in Figures 95A-C. For example, the base of the drainage tube has an S-drainage tube shape (like a drain pipe under a drain), and the inner diameter of the drainage tube expands near the junction with the collection container or elsewhere. The drainage tube may also be bulb-shaped or cone-shaped. As shown in Figure 95C, the drainage lumen is annular. In this embodiment, air bubbles are reduced by directing fluid down the side of the angled cone, similar to how beer is reduced by pouring it down the side of a glass instead of in the center. While the bubble reduction feature is shown here at the base of the drainage tube, it can be located anywhere in the drainage tube or system. In some embodiments, the urinary drainage lumen may be flattened to reconnect urine to a surface. For example, the urine drainage lumen may be flattened to less than about 1 mm. The urinary drainage lumen may be flattened to less than about 2 mm. The urinary drainage lumen may be flattened to less than about 3 mm.

[0352] Urine can also be forced to flow up to a point, as shown in the inverted cone embodiment of FIG. 96A. The cone may be angled, as shown here, or more curved. The cone shape generally transitions from a small area to a large area and / or from a large area to a small area. This and other bubble reduction mechanisms may also be present within the collection reservoir. For example, as shown in FIGS. 96B-D, angled baffles may be incorporated into the collection reservoir to force fluid down onto an angled surface. The angled surface may extend completely to the bottom of the collection reservoir or only partially into the collection reservoir. Different angles may be used, for example, from about 10 degrees to about 80 degrees.

[0353] Angled baffles, such as those shown by the embodiments of Figures 96C and 96D, may also be preferred to improve the accuracy of urine volume measurements, particularly in critical care conditions where a patient's urine output is low and continuous measurement of urine output (mL / min or mL / sec) is desired to diagnose a patient's vulnerability to the development of AKI, sepsis, or other conditions. Accurate measurement of small urine volumes is better measured with conical or angled baffles because the height of the urine column is higher for a given urine volume compared to flat-bottomed baffles or cassettes. An ultrasound transducer or similar transducer in the controller can more reliably measure height and provide accurate measurements of urine volume and output, especially when the patient's kidneys are injured and urine output is low. Furthermore, angled baffles or cassettes (urine collection chambers) are less sensitive to changes in the tilt angle of the controller for small urine volumes compared to flat-surfaced cassettes, reducing measurement error.

[0354] FIG. 97A shows an embodiment of a sensing Foley catheter system in which the drainage lumen extends into the collection container / cassette so that fluid generally drains below the fluid level into the collected fluid. The drainage end of the drainage lumen is cut at an angle to prevent the tubing from contacting the bottom of the cassette and blocking fluid flow. The angled cut 9724 can be approximately 45 degrees, approximately 10-80 degrees, or any suitable angle. Other shapes may be used at the drainage end of the drainage lumen to achieve the same result. For example, FIG. 97B shows a drainage lumen whose tubing is castellated at the drainage end. The castellation 9726 may be any shape, including rounded, rectangular, triangular, scalloped, etc.

[0355] FIG. 97C shows an embodiment of a sensing Foley catheter system in which the drainage lumen extends into the cassette and includes a flattened region 9728. In this embodiment, the cross-sectional area of ​​the drainage lumen can remain the same, increase, or decrease, but the flattened region preferably increases at least one dimension to increase the surface area in contact with the fluid flow. As shown in FIG. 97C, the flattened region can direct the flow downward, or the flattened portion can be angled to force the fluid to contact at least one side of the inner surface of the lumen. Alternatively or additionally, an angled baffle, such as baffle 9730 shown in FIG. 97D, may be used. The angle of baffle 9730 can be approximately 45 degrees, approximately 10-80 degrees, or any suitable angle. Angled baffles or flattened regions may be used with any of the drainage tube / lumen designs shown herein.

[0356] FIG. 98A illustrates an embodiment of a sensing Foley catheter system in which the drainage lumen area is increased or decreased. A bulb 9832 may be incorporated into the drainage tubing above the cassette, within the cassette, or anywhere along the drainage lumen, as shown in FIG. 98D. The areas above and below the bulb may be essentially the same, or the area below the bulb may be smaller than the area above the bulb, as shown in FIG. 98B. The reduced drainage lumen area 9834 may be relatively short; for example, the portion 9834 may be approximately 1 mm to 10 mm in length. Alternatively, the portion 9834 may be approximately 10 mm to 20 mm in length. Alternatively, the portion 9834 may be approximately 10 mm in length. FIG. 98C illustrates an embodiment in which the constriction 9836 includes two or more reduced-area fluid drainage lumens. This allows for increased surface contact of the drainage lumen without significantly reducing the drainage lumen area. The constriction 9836 may be used with or without a bulb 9832.

[0357] It should be noted that any of the bubble reduction embodiments contained herein can be used anywhere in the drainage lumen, including drainage tubing external to the cassette and drainage tubing / lumens within the cassette. For example, Figure 98D shows an embodiment similar to that shown in Figure 98B where the bulb is within the cassette.

[0358] FIG. 99A shows an embodiment of a sensing Foley catheter system in which at least a portion of the drainage lumen is roughened to disperse and / or burst bubbles.

[0359] Figures 99B and 99C show another bubble reduction embodiment. In this embodiment, a grid, honeycomb, or mesh is located inside the base of the drainage tube. The mesh helps break up air bubbles and can be periodically compressed to clear the area of ​​liquid, also helping to break up air bubbles.

[0360] Alternatively, or in addition, a flat mesh may be inserted anywhere within the system, for example, at the drainage tube / collection vessel junction.

[0361] In some embodiments, the cassette and / or drainage lumen may be vibrated continuously or intermittently to break up air bubbles.

[0362] 100A-C show embodiments incorporating a floating or non-floating plate to compress or break air bubbles at or near the surface of the urine in the collection container. The plate can simply float on the surface and passively rise and fall depending on the amount of urine in the container, or the plate can be actively raised and lowered. The plate can also be fixed in place. The plate can be porous or solid. In embodiments where the plate is on the surface of the fluid, the plate can also be used to measure urine output. The position of the plate can be determined by ultrasound, visual means (such as a camera), laser, or other techniques. The volume of fluid in the collection container can be determined directly from the level of the fluid and, therefore, by the position of the plate.

[0363] The interior of the cassette may be rectangular or have other shapes. For example, the interior sides of the cassette may taper inward toward the bottom so that there is a larger upper surface of urine relative to the volume of urine in the cassette. This allows for a more accurate urine volume measurement with a smaller volume.

[0364] Some embodiments may include a volume baffle at a set volume mark, e.g., 50 mL. This volume baffle may be similar to baffle 2302 shown in FIG. 23, except that it is at a predetermined volume position. When the top of the urine volume in the cassette is at or near the volume baffle, the ultrasound signal will be stronger than at other times. For example, the volume baffle can be positioned so that when the top of the urine volume is at approximately 50 mL (or other set volume), the top of the urine volume is at or near the volume baffle. The ultrasound signal is strongest when the two surfaces (urine and volume baffle) are close to or touching each other.

[0365] Some embodiments may include a waveguide to help account for the slope of the reservoir. For example, ultrasonic signals may be directed into a cylinder with flat or curved sides to direct the ultrasonic waves toward the surface of the fluid in the reservoir where they are reflected. The waveguide may extend all or part of the reservoir. The waveguide may extend between the ultrasonic transducer / sensor and the surface of the fluid.

[0366] In some embodiments, the ultrasonic transducer / sensor may be flat, and in some embodiments, the surface of the ultrasonic transducer / sensor may be curved, for example, with a convex curve, which helps spread the ultrasonic signal over more angles, causing some of the angles to be reflected from the surface of the fluid in the reservoir.

[0367] Some embodiments include a controller that uses an accelerometer to measure the tilt of the reservoir and then uses the tilt angle to calculate the volume of fluid remaining in the reservoir (i.e., the low angle of the reservoir) after the fluid has emptied from the reservoir. This calculated amount remaining in the reservoir can be added to the calculation of total urine output to increase accuracy.

[0368] FIG. 101A shows an embodiment of a sensing Foley catheter system that includes valves at both the drainage port 10102 and the entry point 10104 where the drainage tubing connects to the collection reservoir. This allows the controller to periodically apply pressure to the collection reservoir to reduce air bubbles and facilitate drainage of the collection reservoir. This entry port valve also allows the controller to stop urine flow to the collection reservoir during urinary drainage, allowing for more accurate measurement of urine output.

[0369] 101B shows an embodiment of a collection container in which the urine overflow path is longer and / or more convoluted / tortuous and / or narrow. This configuration makes it difficult for air bubbles to flow into the overflow path, resulting in inaccurate urine output measurements. The overflow path may include one or more path angles greater than 45 degrees.

[0370] FIG. 101C illustrates an embodiment of a collection container in which the fluid pathway (indicated by the dashed arrow) between the urine in the reservoir and the cassette pump interface 1148 is convoluted and long to prevent wetting of the interface 1148. The pump interface 1148 may include a gas-permeable, liquid-impermeable filter. The length of the fluid pathway is approximately 6-12 cm. Alternatively, the fluid pathway may be approximately 3-6 cm long. Alternatively, the fluid pathway may be longer than approximately 12 cm. Alternatively, the fluid pathway may be approximately 3-6 cm long. Alternatively, the fluid pathway may be longer than approximately 20 cm.

[0371] 101D shows another embodiment of a long collection container in which the fluid pathway (shown in dashed lines) between the urine in the reservoir and the cassette pump interface 1148 is convoluted to prevent wetting of the interface 1148. The pathway may include small diameter tubing 10108 that is coiled or bundled as all or part of the fluid pathway. Preferably, the convoluted pathway is convoluted in three dimensions.

[0372] 101E shows another embodiment of a long collection container in which the fluid path (shown in dashed lines) between the urine in the reservoir and the cassette pump interface 1148 is convoluted to prevent wetting of the interface 1148. This embodiment includes both small diameter tubing 10108 and a convoluted path molded into the cassette. The tortuous path may be partially molded, partially tubing, or all tubing or all molded.

[0373] The inner diameter of small diameter tubing 10108 may be about 1.8-2.0 mm. In some embodiments, the ID may be about 1.6-1.8 mm. In some embodiments, the ID may be about 1.4-1.6 mm. In some embodiments, the ID may be about 1.2-1.4 mm. In some embodiments, the ID may be about 1.0-1.2 mm. In some embodiments, the ID may be about 0.8-1.0 mm. In some embodiments, the ID may be about 0.5-0.8 mm. In some embodiments, the ID may be about 0.2-5 mm. In some embodiments, the ID may be less than about 4 mm. In some embodiments, the ID may be less than about 3 mm. In some embodiments, the ID may be less than about 2 mm.

[0374] Some embodiments include drainage tubes with small lumen diameters. For example, in some embodiments, the lumen diameter is about 2 mm. In some embodiments, the lumen diameter is about 1 mm. In some embodiments, the lumen diameter is about 3 mm. In some embodiments, the lumen diameter is less than about 2 mm. In some embodiments, the lumen diameter is less than about 1 mm. In some embodiments, the lumen diameter is less than about 3 mm.

[0375] In some embodiments, the expelled urine can be used to "clean" any air bubbles in the drainage tube or collection reservoir. Urine can be circulated through the drainage tube to increase the volume in the drainage tube and "flush" any bubbles in the tube and / or reservoir. The controller compensates for the recycled urine when calculating urine output.

[0376] In some embodiments, pressurized air may be introduced into the drainage tube and / or collection container. The forced air bursts and / or compresses bubbles and forces the urine against the surface of the system, reducing bubble formation. The cross-sectional area of ​​the drainage tube may decrease, remain the same, or increase as the drainage tube transitions to the flattened section.

[0377] Leveling

[0378] In embodiments where urine volume is measured in a collection container using ultrasound, it is important that the ultrasound has a surface (i.e., the surface of the urine volume) that is approximately 90 degrees from the ultrasound sensor. If the system is tilted by several degrees, the ultrasound sensor may not be able to sense the surface of the urine and may not obtain an accurate measurement of urine volume. To compensate for this, the collection container or base / controller may be attached to the bed, for example, via a mount attached to rollers, so that gravity automatically levels the base when attached.

[0379] In some embodiments, slight angles within the system are addressed by creating a "rough" surface for the urine volume in the collection reservoir. The "rough" surface provides multiple angles for ultrasound reflection, some of which are approximately 90 degrees from the ultrasonic sensor / transducer. Roughness can be created by using air or other gas to bubble the urine and vibrate the collection reservoir and / or the urine. Vibration can be achieved mechanically, ultrasonically, or otherwise. Floating plates with rough, concave, or convex undersurfaces that float on the surface of the urine can be used. Floating beads may be too large in diameter to exit the reservoir when urine is emptied, but remain within the reservoir when urine is emptied. Mesh, narrow, small-diameter openings, or other mechanisms may be used to prevent beads from entering the overflow area. Additionally, as described above, angled baffles or angled-walled or tapered-walled cassettes (or urine collection chambers) can also be used to accurately measure urine volume.

[0380] Pressure Balloon Priming

[0381] A very small amount of air or fluid may be required to adjust the pressure in the pressure balloon and prime it for optimal pressure sensing measurements. For this reason, an air / gas / fluid regulator can be used between the priming fluid and the pressure balloon. The regulator allows the priming pump to operate with a smaller amount of air, allowing for more accurate pressure balloon priming. The regulator may include a foam insert, a constriction in the fluid lumen, or other suitable regulator.

[0382] General improvements

[0383] In some embodiments, sensors on the bed, patient, or elsewhere in the sensing Foley catheter system sense whether the patient is supine or not. Pressure measured in the bladder increases when the patient is not supine, which can adversely affect data for analysis by the controller. As a result, the controller may ignore pressure data collected while the patient is not supine or stop collecting pressure data during this time. Alternatively, the pressure measurement itself can be used to detect when the patient is not supine. A sudden increase in pressure or an increase above a certain threshold may indicate the patient is sitting, moving, or coughing. Different pressure profiles may indicate different events. Patient rolling to prevent pressure sores can be tracked in this manner.

[0384] In some embodiments, the heart rate measured via the bladder heart rate is synchronized with the EKG using EKG measurements obtained from leads attached to the sensing Foley catheter system or obtained independently.

[0385] In some embodiments, the bed angle may be used by the controller as an input parameter into calculations such as IAP or APP. For example, increasing the body angle (raising the patient's head height) increases IAP. This increase may differ between healthy and unhealthy patients. As a result, determining IAP at various bed angles may provide additional information about the patient's health. Additionally, lowering the head level may decrease IAP and temporarily stabilize patients with high IAP.

[0386] In some embodiments, the sensing Foley catheter has at least one pressure sensor or lumen in fluid communication with an external pressure sensor. This pressure sensor allows for rapid or frequent detection of pressure within the lumen (ideally at a rate greater than 1 Hz) and monitoring of physiological signals within the lumen. In some embodiments, the pressure lumen may be manually or automatically inflated and / or deflated while the pressure is continuously or intermittently monitored. In embodiments where the pressure lumen includes a pressure balloon, the pressure exerted by the body on the pressure balloon is monitored while the balloon is inflated and / or deflated. The pressure lumen can transmit pressure waves from body cavities, one of which is cardiac pulsation caused by the inflow of blood into luminal organs and / or surrounding tissues. Pulsatile pressure from cardiac pulsation and / or respiratory excursion can be used to determine pulmonary and cardiovascular pressures. Furthermore, the pressure in the pressure lumen / balloon may increase above a threshold (i.e., 100 mmHg) and then slowly decrease within the sensing range to determine the onset / disappearance of the pulse pressure, the extinction point of the pulse pressure, and / or the relative increase / decrease in pressure pulse size. The onset / disappearance or relative increase / decrease of the pressure pulsation detected by the pressure sensor may be correlated to blood pressure, perfusion pressure, mean arterial pressure, stroke volume, stroke volume variation, respiratory effort, pulmonary pressure transmission, and other pulmonary, gastrointestinal, renal, or cardiovascular parameters. This process may be similar to a blood pressure cuff, where the pressure rises above blood pressure and the pressure in the cuff slowly decreases until a blood pressure waveform (heartbeat) appears or disappears.

[0387] Figure 102 shows the pressure waveform and its decay as the pressure balloon is inflated. Note that above mean arterial pressure, the heart beat is reduced and / or eliminated. If there is enough data to correlate the degree of decay at the relative pressure points with mean arterial pressure, the mean arterial pressure can be derived from this relative pressure waveform. The same can be used for pulmonary pressure or other pressures that can be sensed within body cavities.

[0388] In some embodiments, the pressure sensor / lumen is a capsule, or balloon, or reservoir that can be slowly inflated or filled while pressure is monitored using an external transducer. In some embodiments, the pressure sensor is associated with a urethral catheter, such as a Foley catheter. Alternatively, the pressure sensor may be associated with a nasogastric, orogastric, or rectal tube. In yet other embodiments, the pressure sensor device and associated pressure augmentation device may be fully implantable. In tissue perfusion embodiments, a pressure sensor may be inflated within the urethra or against the luminal surface, and pulse oximetry may be performed to detect blanching and / or perfusion of the luminal tissue at each pressure to determine tissue perfusion pressure.

[0389] In some embodiments, the catheter can synergistically use multiple measured parameters to improve the quality of data analysis. In one embodiment, the catheter incorporates a sensor to capture an ECG signal internally via the urethra or bladder, or externally via a sensor placed on the leg or buttocks. This signal can be used to synchronize other measured parameters (such as stroke volume) that are synchronized with the cardiac cycle with the electrical signal, and noise can be removed by obtaining an average or median signal from many individual samples. In another embodiment, the respiratory signal is used to guide which cardiac pressure signal should be used in stroke volume variation analysis by waiting for a model waveform to appear before performing the analysis.

[0390] Figure 103 illustrates a method for synchronizing a cardiogenic signal (such as bladder pressure fluctuations caused by the nearby abdominal aortic pulse) to obtain a clean signal for analysis. Once an ECG is acquired synchronously with another cardiac signal of interest, individual samples can be synchronized, for example, using the ECG R wave. In this illustration, multiple pressure samples are acquired and then overlaid using the ECG R wave for alignment. The signal median is then calculated by simultaneously taking the median of all pressure samples during the cardiac cycle. Averaging can also be used. This method filters out random noise because an outlying high value due to noise in one sample is offset by an equally outlying low value in another sample. As data points are added, the underlying signal becomes stronger and can be used for analysis. For example, in the pressure signal shown, the signal's peak-to-peak amplitude can be used to derive relative stroke volume.

[0391] Figure 104 illustrates a method for using a respiratory pressure signal to inform cardiac pressure signal analysis to determine stroke volume variability (SVV). This method is particularly valuable in non-ventilated patients, i.e., patients not using a ventilator. Existing techniques for measuring stroke volume, such as thermodilution and pulse contour analysis, are limited in their ability to perform measurements of stroke volume variability (i.e., variability in stroke volume between inspiration and expiration) because they are not affected by the respiratory cycle. Using intraluminal pressure devices such as an intravesical Foley catheter as described herein has the advantage of allowing simultaneous capture of respiratory and cardiac signals (similarly slow-moving intra-abdominal pressure). In this way, this device can differentiate and select respiratory cycles to use for stroke volume variability analysis because certain characteristics are more suitable for appropriate analysis (e.g., respiratory rate and size). In this figure, a sample pressure signal captured from the bladder is shown. In the raw pressure signal above, large fluctuations are due to respiration and are selected for analysis based on, for example, wave width, amplitude, or peak value. Other characteristics not shown can also be used to define a suitable wave, including slope, area under the curve, shape, frequency, pattern, repeatability, etc. A curve amplitude filter can be used if there is a curve with an amplitude above a certain value, and values ​​below that, or another specified value, are not used in the calculation of SVV. The figure below shows the same signal after passing through a high-pass and low-pass filter. The high-pass filter retains the underlying cardiac signal (dashed line), and the low-pass filter retains the underlying respiratory signal (solid line). In this example, the difference in cardiac signal strength between the peaks and valleys of the respiratory signal (e.g., peak-to-peak value) can be used to calculate stroke volume variability.

[0392] Respiratory rate and other parameters may be sensed via a sensing Foley catheter or may be sensed or acquired by any conventional or non-conventional means. Other parameters that may be collected include data collected via tidal volume, spirometry, respiratory flow parameters, spirometry, expiratory effort, inspiratory effort, etc. Any of these parameters may be used to assist in the calculation of stroke volume variability and / or other cardiac parameters.

[0393] The filter used to determine which pressure peaks are used in the SVV calculation may be based on any of the pressure curve parameters disclosed herein. Additionally, the SVV calculation itself can be used to determine the pressure curve peaks used in the calculation. For example, SVV is typically within about 10%. The systems disclosed herein may include or exclude pressure curve data based on the resulting SVV calculation being within a certain value, such as about 10%.

[0394] SVV calculations can also be patient-specific. For example, a peak filter for a pressure curve may be based on amplitude, but the cutoff amplitude may be patient-specific and based on the mean, average, or other parameter of that patient's pressure curve. Alternatively, the filter may be based on multiple patients, or multiple patients within a particular category, such as a particular disease state.

[0395] The signal and / or SVV calculation may also be filtered for patient movement and / or other artifacts such as coughing, shifting, sneezing, etc.

[0396] Additionally, a calculated result of very low or non-existent SVV may be an indicator of fluid overload and appropriate treatment may be indicated.

[0397] In some embodiments of the disclosed system, the patient may be prompted to breathe in a particular manner. For example, based on the shape of the pressure curve (peak amplitude, frequency, etc.), the system may prompt the patient to breathe deeper, breathe slower, breathe normally, etc. The resulting respiratory pressure curve can be incorporated into the calculation of SVV. This type of prompt may be performed by the system if the pressure curve is insufficient to provide an SVV calculation, or for other reasons.

[0398] Figures 105A and 105B show two views of the base piece of the sealing mechanism between the cassette and the controller. Typically, the base piece shown in Figures 105A and 105B connects to the cassette, and the pin shown in Figure 106 connects to the controller. However, the connectors can be reversed, with the pin connected to the cassette and the base connected to the controller. The purpose of the sealing mechanism is to connect the lumens of the cassette to the lumens of the controller when the cassette is connected to the controller, but also seal the lumens of the cassette when the cassette is disconnected from the controller. For example, the cassette may be temporarily disconnected from the monitor / controller when a patient undergoes surgery or is moved from one room to another. While the cassette is disconnected from the controller, it may be desirable to seal the lumens of the cassette to prevent contamination and to prevent urine, liquids, or gases from leaking or entering the system.

[0399] For example, lumens such as pressure balloon lumens (such as pressure transducer interface 1026), vent lumen 1150, cassette pump interface 1148, and / or cassette pressure interface 1150 may have such connectors.

[0400] The base portion 1050 of the connector is shown in FIGS. 105A and 105B. The base can be made of a highly compressible, inert material such as silicone or rubber. The base portion 1050 includes a base head 10504, a base stem 10508, and a base anchor 10502, as well as a slit 10506 having a length L3. Preferably, the slit 10506 is a single linear slit, but because a sharp knife is provided after molding the base, the slit does not have rounded edges and can be completely sealed in a relatively relaxed state. When the base 1050 is connected to a lumen, fluid cannot flow through the slit in the base.

[0401] The pin portion 1060 shown in FIG. 106 includes a pin head 10604 and a pin stem 10602 that includes a lumen therethrough. The pin stem 10602 has an outer diameter D3. The pin 1060 fits inside a slit 10506 in the base 1050, and when so positioned, allows fluid to pass through the sealing mechanism. In some embodiments, L3 is approximately the same as D3.

[0402] 107A and 107B show a pin 1060 inserted into a slit 10506 in the base 1050, which allows fluid to flow through the lumen of the pin and the sealing mechanism.

[0403] 108 shows the base portion of the sealing mechanism 1050 on the back of the cassette, which is designed to snap into an opening in the controller. The base portion of the sealing mechanism shown here is connected to a pressure balloon lumen interface 10802, a vent lumen interface 10804, a cassette pump interface 10806, and a cassette pressure interface 10808 (for measuring IAP). Note that all, some, or none of the cassette interfaces may use these types of sealing mechanisms. For example, the pressure interface 10808 for measuring IAP does not need to seal when the cassette is removed and may use a different type of connector.

[0404] Figure 109 shows the operation of the sealing mechanism when the cassette is connected to the controller. The cassette 1022 is shown in cross section with one of the sealing mechanisms installed. The base 1050 attaches to the cassette portion and would be sealed if the pin 1060 were not present. The pin 1060 is connected to the controller (not shown), and when the cassette 1022 is snapped into place on the controller, the pin 1060 is inserted into a slit in the base 1050, allowing fluid to pass between the cassette and the controller. The connection can include a filter, shown here as filter 10902.

[0405] Figure 110 shows the approximate dimensions of an embodiment of the base 1050. These dimensions may vary from application to application.

[0406] FIG. 111 illustrates some of the forces exerted on the base 1050 when fully installed in the cassette. These forces are caused by the diameter of the mounting hole and the diameter of the stem 10508, as well as the thickness of the cassette wall and the length of the stem 10508. Additionally, compressive forces may press against the base head 10504 when the cassette is installed in the controller. These forces tend to tighten the seal of the base 1050, regardless of whether a pin is inserted in the slit. That is, based on the dimensions and shape of the base, the slit will be subjected to a force that either keeps it closed or keeps the pin closed. The force pushes the slit inward. The base head 10504 is slightly concave (mushroom-like) at the bottom, expands at the bottom (wider portion), and tends to compress at the top (where the slit opening is). This is especially true if the cassette wall thickness is greater than the length of the stem 10508.

[0407] In some embodiments, multiple drainage lumens can be used to prevent airlock. The proximal and / or distal openings can be offset. Lumens can be incorporated into single or multiple tubes, with or without siphoning. For example, two drainage lumens can be used, three drainage lumens can be used, four drainage lumens can be used, five drainage lumens can be used, six drainage lumens can be used, seven drainage lumens can be used, eight drainage lumens can be used, or more than eight drainage lumens can be used.

[0408] In any of the embodiments disclosed herein, the vent tube can be connected to a standard or non-standard Foley catheter by attaching it to the sampling port of the Foley catheter or anywhere in the sampling port drainage system on a barb near the Foley catheter. See, e.g., FIG. 112.

[0409] FIG. 112 illustrates an embodiment including a venting mechanism / vent tube that can be added to any urinary drainage system that includes a sampling port 1004 or any other suitable port. In this embodiment, the venting mechanism 11200 can turn the sampling port 1004 into a vent for the system, avoiding an airlock. The venting mechanism 11200 includes a vent tube 11202 and, optionally, a valve 11204 and / or a filter 11206. The venting mechanism may also include a needle or puncture mechanism or blunt tube 11208 that punctures or opens / accesses the sampling port 1004 and maintains an opening in fluid communication with the drainage lumen 1012 to perform the drainage function. In this illustration, the sampling port is shown as part of the barb 1016, but the sampling port can be located anywhere in the drainage system. Alternatively, other ports or access points can be used. This embodiment can be used with or without a vacuum pump. The vent tube may be rigid, flexible, or bendable. The venting mechanism can include means for suspending the vent tube above the level of the bladder, e.g., 1-10 cm above the level of the bladder. The vent tube can be greater than 1 cm in length. Alternatively, the vent tube can be greater than 2 cm in length. Alternatively, the vent tube can be greater than 3 cm in length. Alternatively, the vent tube can be greater than 4 cm in length. Alternatively, the vent tube can be greater than 5 cm in length. Alternatively, the vent tube can be greater than 10 cm in length. The ID of the vent tube can be less than about 5 mm. Alternatively, the inner diameter of the vent tube can be less than about 4 mm. Alternatively, the ID of the vent tube can be less than about 3 mm. Alternatively, the ID of the vent tube can be less than about 2 mm. Alternatively, the ID of the vent tube can be less than about 1 mm.

[0410] While the vent tube 11202 is shown terminating in the atmosphere in this illustration, the vent tube may also be connected to a drainage bag as shown in FIG. 11E. If a valve and vent are present, the valve may be between the sampling port and the vent, or the vent may be between the sampling port and the valve. This type of vent mechanism can be implemented on the sampling port after an initial volume of urine has been drained from the bladder. This type of vent mechanism can be incorporated into a strap or patch for securing the barb to the patient's leg or other location. The vent mechanism / vent tube in this embodiment may have one or more narrow diameter sections along its length, as shown in FIG. 11D. For example, a section of the vent tube 11202 may be relatively long with a relatively small diameter to prevent urine from traveling through the vent tube and reaching the valve and / or filter.

[0411] Instead of using a puncture mechanism 11208 with the sampling port 1004, a puncture mechanism may be used along the tubing of the catheter or drainage tube. Alternatively, a mechanism in which the port is normally closed but accepts an additional vent mechanism / vent tube can be used. For example, a sealing mechanism pin configuration such as that shown in FIGS. 105-111 can be used where the base is on the catheter / drainage tube and the pin is part of the vent mechanism / vent tube, or vice versa. In some embodiments, the port 1004 may be on an add-on barb or connector piece intended to be placed between the catheter and the drainage tube.

[0412] FIG. 113 shows an embodiment including a pump / argon 11302. The pump preferably acts on the outside of the drainage tube 1012, urging fluid within the drainage tube toward the drainage bag. The pump may be a peristaltic pump, a pump with rollers, a pump that applies cyclic pressure, or the like. In a very simple cyclic pressure pump embodiment (shown diagrammatically here), the ID of the drainage tube changes along its length so that fluid flows primarily in one direction, in this case toward the drainage bag. The ID on the patient end of the drainage tube may be smaller than the ID on the drainage bag end of the drainage tube. As shown in this close-up view, the ID may decrease or the change in ID may be gradual.

[0413] FIG. 114 shows an embodiment in which the drainage tube 1012 includes a coiled or compressed section 11402. In this embodiment, slack in the drainage tube is reduced. The coil may be supported by a shape memory material or by a physical clip or some type of holder. Preferably, the drainage tube can stretch to accommodate patient movement.

[0414] Figures 115A and 115B show an embodiment of a barb that includes a tube seating mechanism. The barb 11502 contains a urinary drainage tube 11504 that surrounds a urinary drainage lumen 11506 and a vent tube 11508 that surrounds a vent lumen 11510. The tubes 11504 and 11506 are inserted into the barb during manufacture and seated at step 11512. This allows both the urinary drainage lumen and the vent lumen to open into a single inner lumen 11516 of the catheter manifold 11514, as shown in Figure 115B.

[0415] In some embodiments, the controller controls a pressure sensor at or near the barb to determine when the pressure in the barb area is not too negative so that a vacuum can be pulled on the drainage line without causing aspiration trauma to the bladder. The pressure sensor can also be used to determine the initial positioning of the system and ensure that the pressure in the drainage line is not too positive or too negative. If the pressure in the drainage line is too low, the controller can operate a valve in the urine collection reservoir or elsewhere to temporarily stop or slow urination, reducing the pressure and reducing the possibility of aspiration trauma to the bladder.

[0416] In some embodiments, the bladder is periodically pressurized to aid in the evacuation of urine from the bladder, which can be accomplished using a retention balloon, a pressure-sensitive balloon, another balloon, etc.

[0417] In some embodiments, the airlock clearance is performed intermittently, hi some embodiments, the airlock clearance is performed continuously, for example, by pulling a continuous slight vacuum on the drainage line.

[0418] In some embodiments, pulse oximetry data may be collected from the patient's skin, for example from the thigh, or from somewhere in the groin or leg.

[0419] In some embodiments, the controller manages the air volume and / or pressure throughout the system. For example, the controller senses overpressure in the urine collection bag, which can occur if the air filter (shown as 1142 in some figures) is blocked or wet. This increases the risk of the bag breaking. If this occurs, the controller may instruct the system to do one or more things to mitigate the problem. The controller may attempt to clear the filter by blowing a "puff" of air through it. The controller may slow or stop urine output by slowing or stopping the airlock clearance pump. The controller may instruct the pump to intermittently reverse direction to reduce pressure in the drainage bag. The controller may alert the user to change or manually correct any issues with the drainage bag. The controller monitors pressure anywhere in the system to identify and potentially mitigate pressure-related problems. The controller can monitor pressure in the barbs, drainage lines, vent lines, reservoirs / cassettes, drainage bags, etc. For example, the controller can control the pressure within the cassette to empty the cassette, empty the filter, reduce bubbles, etc.

Claims

[Claim 1] a catheter having at least one opening at or near its distal end for insertion into the body; a barb in fluid communication with the proximal end of the catheter; a drainage tube in fluid communication with the at least one opening and the barb; a vent tube in fluid communication with the drainage tube; a one-way valve disposed in line with the vent pipe; a controller controlled to apply a negative pressure to the drainage tube, the negative pressure acting directly on the one-way valve and the action of fluid passing through the vent tube causing the one-way valve to open to the atmosphere; A catheter system comprising:

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