Systems, apparatus, and methods for the drainage and analysis of bodily fluids

Abstract

To provide systems, devices and methods for draining and analyzing body fluids in which a drainage assembly is configured to prevent negative pressure build-up.SOLUTION: The drainage assembly generally includes a catheter which may include a drainage lumen, a reservoir, a venting mechanism in fluid communication with the drainage lumen and a positive pressure lumen 6702 and a controller. The venting mechanism may further include a valve 6702 which is configured to maintain a closed position; and a vent 6704 in fluid communication with the valve. The venting mechanism is configured to inhibit wetting of the vent from fluid within the drainage lumen.SELECTED DRAWING: Figure 67

Description

Technical Field

[0001] This application claims the benefit of priority from U.S. Provisional Application No. 62 / 256,257 filed on November 17, 2015, U.S. Provisional Application No. 62 / 270,022 filed on December 20, 2015, U.S. Provisional Application No. 62 / 270,623 filed on December 22, 2015, U.S. Provisional Application No. 62 / 275,348 filed on January 6, 2016, U.S. Provisional Application No. 62 / 290,878 filed on February 3, 2016, U.S. Provisional Application No. 62 / 307,988 filed on March 14, 2016, U.S. Provisional Application No. 62 / 317,746 filed on April 4, 2016, and U.S. Provisional Application No. 62 / 372,731 filed on August 9, 2016, is a continuation application of U.S. Patent Application No. 15 / 277,957 filed on September 27, 2016, which relates to PCT Application No. PCT / US2014 / 44565 filed on June 27, 2014, PCT Application No. PCT / US2015 / 010530 filed on January 7, 2015, and PCT Application No. PCT / US2015 / 52716 filed on September 28, 2015, each of which is hereby incorporated by reference in its entirety.

[0002] The present invention relates to the field of medical devices, in particular, to devices that assist urination from the bladder, measure various urine parameters including urine volume, oxygen pressure, urine conductance, urine specific gravity, etc., monitor renal function, analyze urine parameters including urine components and the presence or absence of infection, and track and / or control fluid administration. The present invention further relates to a medical device capable of detecting physiological data based on a sensor incorporated into a catheter adapted to be placed in any of the urinary tract, gastrointestinal tract, rectal region, preperitoneal space, pleural cavity, or other body cavities.

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

Background Art

[0004] It is estimated that 10% of all hospitalized patients receiving long-term care have indwelling urinary catheters. Almost all critically ill patients have them, and monitoring hourly urine output is a routine procedure in the ICU. Urine production is an indicator of fluid status and renal function. However, numerous sources of error can lead to inaccuracies in the measurement of this important indicator.

[0005] The most common device used for bladder drainage is the Foley catheter. The design of the flexible tube, which features an indwelling balloon and a small opening for draining urine through a central lumen, has remained largely unchanged since its introduction. However, the current design of the Foley catheter can leave more than 50 mL of residual urine in the bladder, for example, 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. One study found the average residual volume to be 96 mL in the ICU and 136 mL in general wards. See Garcia et al., Traditional Foley Drainage Systems—Do They Drain the Bladder?, J Urol. 2007 Jan;177(1):203~7;discussion 207. Large amounts of residual urine are frequently found in the drainage bag or in the drainage tube connecting the Foley catheter to another part of the drainage system. [Overview of the project] [Problems that the invention aims to solve]

[0006] Residual urine in the bladder and drainage tube results from large air bubbles (airlocks) forming within the tube, obstructing the flow of urine from the bladder to the drainage bag. Consequently, assisting patients in emptying the drainage tube before measuring urine volume has become a routine procedure for nurses. In the ICU, measurements are taken frequently, such as hourly, making this a highly repetitive and inaccurate process. There is a need for more accurate and automated urine volume measurement.

[0007] Furthermore, the urine collection system provides an opportunity to measure and analyze urine parameters.

[0008] In addition to improving urine volume measurement and urine parameter analysis, the urinary catheter itself presents a previously undeveloped opportunity to detect, collect, and analyze additional patient parameters.

[0009] Furthermore, many types of medical devices are designed to control the treatment and / or maintenance of a patient. For example, ventilators can control the patient's respiratory rate, volume, and / or gas mixture. Intravenous (IV) delivery can deliver fluids and / or other substances, such as drugs, to the patient. Other devices include those that can deliver drugs or exert other effects. These types of medical devices can be strictly controlled through various settings. Nurses or other practitioners may check various patient parameters and adjust the settings of the medical device accordingly. Controllers are needed that automatically or semi-automatically use patient parameters to control the settings of the medical device. [Means for solving the problem]

[0010] Foley catheters are widely used, low-cost, and easily positioned by healthcare professionals. However, by modifying and / or adding functionality to Foley catheters, they may be used as a medium for deriving critical diagnostic information. The technology of this disclosure enables the delivery of highly degraded, previously unobtainable diagnostic information, which may be derived from a Foley catheter equipped with intraperitoneal pressure (or other) sensing capabilities.

[0011] Furthermore, airlock amplification is known to significantly distort intraperitoneal pressure readings. An incomplete bladder can also negatively affect bladder pressure readings. The technology of this disclosure enables the detection and removal of airlocks in intraperitoneal pressure measurement or other settings, and allows for more complete bladder drainage.

[0012] The technology of this disclosure aims to improve the accuracy of automated urine volume measurement by more effectively draining from the bladder, preventing the formation of airlocks in the drainage tube, removing airlocks when they do form. The technology of this disclosure also aims to improve the monitoring of fluid conditions, renal function, and other important patient parameters by incorporating additional urine measurements including oxygen pressure, conductance, specific gravity, gas pressure, turbidity, infection, sediment, and others.

[0013] The technology of this disclosure also relates to a Foley-type catheter that senses physiological data from a patient's bladder and / or urinary tract, which includes, in particular, data collected by high-fidelity pressure sensing and conversion to a signal suitable for processing. In some embodiments, the pressure-sensing Foley-type catheter may also be able to sense temperature and clinically significant specimens. Examples of physiological parameters that a sensing Foley catheter system may measure (time-specific measurements and trends in numerical values ​​over time) include urine volume, respiratory rate, heart rate, heart rate variability, stroke volume, stroke volume variability, intraperitoneal pressure (IAP), tissue oxygenation, tissue gas content, pulse fiber time, pulmonary blood flow variability, temperature, blood components, and other patient parameters.

[0014] One embodiment of a drainage assembly configured to prevent an increase in negative pressure typically comprises a stretch catheter having a first end configured to be inserted into a body cavity. The catheter may have a stretch catheter having at least one opening near or at the first end, fluidly communicating with the catheter lumen such that the catheter lumen is defined through fluid communication; a drainage lumen fluidly communicating with the second end of the catheter; a container fluidly communicating with the drainage lumen; and a venting mechanism fluidly communicating with the drainage lumen and the positive pressure lumen. A valve may be located within the venting mechanism and configured to maintain a closed position until a first pressure level in the drainage lumen drops to a second pressure level and the valve moves to an open position. A vent port may also be located in fluid communication with the valve, the venting mechanism is configured to prevent the vent port from being wetted by the fluid in the drainage lumen, and a controller is in communication with the container and configured to determine the amount of fluid collected in the container.

[0015] In other embodiments, the drainage assembly may be configured to prevent an increase in negative pressure and typically has a first end configured to be inserted into a body cavity, and comprises an extension catheter having at least one opening near or at the first end, fluidly communicating with the catheter lumen, such that the catheter lumen is defined through fluid communication. The drainage lumen may also fluidly communicate with a second end of the catheter, a positive pressure lumen fluidly communicating with the drainage lumen, a container fluidly communicating with the drainage lumen, and a vent connected to the drainage lumen, and the venting mechanism is configured to prevent the vent from being wetted by the fluid in the drainage lumen. A controller may communicate with the container and may be configured to determine the amount of fluid collected in the container, and may also be provided with 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 falls to a second pressure level.

[0016] Certain patient parameters that may be measured and / or determined by the technology of this disclosure are affected and / or influenced by patient treatment by medical treatment devices. For example, patient urine volume, respiratory rate, heart rate, stroke volume, stroke volume variability, intraperitoneal pressure (IAP), tissue oxygenation, tissue gas content, temperature, blood components, and other patient parameters are affected and / or influenced by medical treatment. Some examples of medical treatments that may be 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, urine volume controlled by a urine volume pump, ascites volume controlled by an excretion pump, and other treatments controlled by other medical treatment devices.

[0017] One embodiment of a system for analyzing bodily fluids may further comprise: a stretch catheter having an expandable balloon located near or at the distal end of the catheter, with one or more openings further defined near the balloon; a ventilation mechanism connected to the proximal end of the catheter and configured to allow air to pass through when negative pressure is applied to the ventilation mechanism; a first lumen connected to the ventilation mechanism and in fluid communication with one or more openings; a second lumen in fluid communication with the balloon; a container connected to the proximal end of the first lumen and in fluid communication with one or more openings; and a controller configured to connect to the container and further programmed to control the pressure in the first lumen, wherein the controller is further programmed to monitor the amount of urine received from the patient into the container and to determine the patient's intraperitoneal pressure based on pressure changes in part of the balloon; and the controller is further configured to store patient data.

[0018] In one example of a method for analyzing one or more physical parameters from a patient, the method may typically include: positioning a stretch catheter having an expandable balloon located near or at the distal end of the catheter within a body cavity at least partially filled with body fluid; receiving urine through one or more openings defined along the catheter adjacent to the balloon; further receiving body fluid into a container located outside the body cavity and fluid-communicated with one or more openings via a fluid lumen; venting air through a ventilation mechanism communicating with the fluid lumen when negative pressure is applied to the fluid lumen; analyzing the amount of urine received in the container via a controller programmed to control the negative pressure to the ventilation mechanism; determining the patient's intra-abdominal pressure based partially on pressure changes within the balloon; and storing one or more parameters of the patient via the controller.

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

[0020] A pressure-measuring balloon provided in a catheter disclosed in International Patent Application No. PCT / US14 / 44565, titled Sensing Foley Catheter (in whole, incorporated herein by reference), is an example of a device for measuring patient parameters. Additional embodiments are disclosed herein. A sensing Foley catheter system may be equipped with a pressure-measuring balloon and / or other sensors and the ability to measure volume and urine volume to determine patient parameters such as urine volume percentage, IAP, respiratory rate, heart rate, stroke volume, tissue oxygenation, urine composition, temperature, and other patient parameters.

[0021] Other parameters that may be measured and / or determined via a sensing Foley catheter include urine specific gravity and pulse pressure variation. These parameters may be used to assist in the control of medical devices such as inhalers and / or intravenous 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. Measurements above this range may indicate dehydration or other symptoms. Measurements below this range may indicate fluid over-infusion or other symptoms. The measurement may be performed by a sensor installed in a sensitive Foley catheter. The measurement results may indicate an increase (in case of dehydration) or decrease (in case of fluid over-infusion) infusion rate to the patient. The measurement results may also indicate a change in inhalation parameters or drug infusion, etc.

[0023] Pulse pressure variation can be a predictor of fluid responsiveness for medical treatment devices such as inhalers and / or infusion devices. A sensing Foley catheter can record pressure waveforms, and a controller can identify maximum and minimum compression pulses that coincide with the respiratory cycle. The controller can calculate pulse pressure variation. Pulse pressure variation can assist in determining whether a particular patient will or will not respond to fluid therapy. Pulse pressure variation can also be used by the controller to control therapy in a feedback loop. If pulse pressure variation is large, the patient may require more fluid. If pulse pressure variation is small, less fluid may be required.

[0024] A sensing Foley catheter system can measure cardiac activity via intravesical pressure sensing. A sensing Foley catheter can measure respiratory activity and cardiac activity, and since the frequency of respiratory rate and a patient's heart rate can be similar to each other, the patient's respiratory measurement can distort cardiac measurement. To overcome this challenge, some embodiments of the controller may stop the respirator at the end of one or more inspiratory points and / or stop the respirator at the end of one or more expiratory points (only for a few seconds each time, for example, 1 to 3 seconds, or for example, 1 to 4 seconds), so that a cardiac waveform can be obtained without respiratory distortion. Obtaining such detailed cardiac waveforms allows the controller to determine stroke volume variation (SVV), which is useful for detecting sepsis and preventing excessive fluid infusion. In an alternative embodiment, the patient may be instructed to hold their breath at inspiratory points and / or expiratory points.

[0025] The novel features of the present invention will be described. 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 that utilize the principles of the present invention. The accompanying drawings are described below. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] [Figure 1] Figure 1 shows an embodiment of a sensing Foley-type catheter. [Figure 2] Figure 2 shows an example of respiratory rate sensing data. [Figure 3] Figure 3 shows a detailed portion of the respiratory profile. [Figure 4] Figure 4 shows an example of heart rate and relative cardiac output sensing data. [Figure 5] Figure 5 shows data related to relative cardiac output sensing during human leg-raising exercises. [Figure 6] Figure 6 shows an example of peritoneal sensing data. [Figure 7] Figure 7 shows an example of peritoneal sensing data. [Figure 8] Figure 8 shows the relationship between intra-abdominal pressure, respiratory wave pressure, and cardiac pressure. [Figure 9] Figure 9 shows a flowchart of one embodiment of the method. [Figure 10A] Figure 10A shows one embodiment of a sensing Foley catheter system. [Figure 10B] Figure 10B shows a detailed diagram of the airlock cleaning mechanism and fluid sampling and analysis system shown in Figure 10A. [Figure 10C] Figure 10C shows a disposable component of one embodiment of a sensing Foley catheter system. [Figure 11] Figure 11 shows another embodiment of the sensing Foley catheter system. [Figure 12] Figure 12 shows another embodiment of the sensing Foley catheter system. [Figure 13] Figure 13 shows another embodiment of the sensing Foley catheter system. [Figure 14A] Figure 14A shows one embodiment of a crushable drainage tube that is placed in a twist-resistant tube. [Figure 14B] Figure 14B shows one embodiment of a crushable drainage tube that is placed in a twist-resistant tube. [Figure 15] Figure 15 shows an example of the cleaning mechanism of a sensing Foley catheter system. [Figure 16]Figure 16 shows an example of the cleaning mechanism of a sensing Foley catheter system. [Figure 17] Figure 17 shows one embodiment of a sensing Foley catheter system equipped with a drainage tube having a gas sampling lumen. [Figure 18] Figure 18 shows an active ventilation system equipped with vents and a pump. [Figure 19] Figure 19 shows one embodiment of a sensing Foley catheter system with additional vents for pressure relief and sterilization. [Figure 20] Figure 20 shows one embodiment of a sensing Foley catheter system equipped with a pressure relief vent and a relief valve. [Figure 21] Figure 21 shows one embodiment of a collection tube, chamber, or cassette that may be provided in a sensing Foley catheter system for detecting bacteria, blood, and / or other substances in urine using UV / optical spectroscopy. [Figure 22] Figure 22 shows various light absorption waveforms of E. coli in urine, red blood cells, and plasma. [Figure 23] Figure 23 shows one embodiment of a cassette equipped with a baffle or flap. [Figure 24] Figure 24 shows graphs illustrating pressure balloon priming methods in several embodiments. [Figure 25] Figure 25 shows graphs illustrating pressure balloon priming methods in several embodiments. [Figure 26] Figure 26 shows flowcharts of possible logic in various embodiments of the present invention. [Figure 27] Figure 27 shows flowcharts of possible logic in various embodiments of the present invention. [Figure 28] Figure 28 shows flowcharts of possible logic in various embodiments of the present invention. [Figure 29] Figure 29 shows one embodiment of a sensing Foley catheter system with a loop controller in a patient environment. [Figure 30] Figure 30 shows one embodiment of a sensing Foley catheter system with a loop controller in a patient environment. [Figure 31] Figure 31 shows one embodiment of a sensitive Foley catheter system with a loop controller in the patient's environment. [Figure 32] Figure 32 shows one 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 along with possible input parameters and output effects. [Figure 34] Figure 34 shows plots of ultrasonic and pressure measurements for differences in quantity. [Figure 35] Figure 35 shows the distal end of one embodiment of a sensing Foley catheter. [Figure 36] Figure 36 shows one embodiment of a filter inside a balloon. [Figure 37] Figure 37 shows one embodiment of the filter inside a balloon when the balloon is inflated. [Figure 38] Figure 38 shows one embodiment of the filter inside a balloon when the balloon is deflated. [Figure 39] Figure 39 shows one embodiment of a filter inside a balloon. [Figure 40] Figure 40 shows one embodiment of a filter inside a balloon. [Figure 41] Figure 41 shows one embodiment of a filter inside a balloon. [Figure 42] Figure 42 shows one embodiment of a filter inside a balloon. [Figure 43] Figure 43 shows one embodiment of a filter inside a balloon. [Figure 44] Figure 44 shows one embodiment of a filter inside a balloon. [Figure 45] Figure 45 shows one embodiment of a filter inside a balloon. [Figure 46] Figure 46 shows one embodiment of a filter inside a balloon. [Figure 47] Figure 47 shows one embodiment of a balloon equipped with multiple access lumens. [Figure 48] Figure 48 shows one embodiment of the balloon. [Figure 49] Figure 49 shows one embodiment of the balloon. [Figure 50] Figure 50 shows various embodiments of a balloon catheter equipped with a gas permeable membrane. [Figure 51] Figure 51 shows various embodiments of a balloon catheter equipped with a gas permeable membrane. [Figure 52] Figure 52 shows various embodiments of a balloon catheter equipped with a gas permeable membrane. [Figure 53] Figure 53 shows various embodiments of a balloon catheter equipped with a gas permeable membrane. [Figure 54] Figure 54 shows a controller that measures gas content via a balloon catheter. [Figure 55] Figure 55 is a schematic diagram of the gas measurement catheter / controller system. [Figure 56] Figure 56 is a schematic diagram of the gas measurement catheter / controller system. [Figure 57A] Figure 57A shows an embodiment of an additional component for gas measurement. [Figure 57B] Figure 57B shows an embodiment of an additional component for gas measurement. [Figure 58A] Figure 58A shows a table listing parameter combinations that, based on patient parameters, enable potential characteristic properties for identifying acute kidney injury and UTIs. [Figure 58B] Figure 58B shows a table listing combinations of parameters that, based on the patient's parameters, enable potential characteristic features for identifying acute kidney injury, sepsis, and acute respiratory distress syndrome. [Figure 59] Figure 59 shows the pressure characteristic property curve inside the collection chamber during airlock cleaning. [Figure 60]Figure 60 is a block diagram of a data processing system, which may be used in conjunction with any embodiment of the present invention. [Figure 61] Figure 61 shows alternative waveforms that can be used to identify red blood cells and / or plasma / white blood cells. [Figure 62] Figure 62 shows postprandial urine volume data for patients who have received diuretics. [Figure 63A] Figure 63A shows how a small-diameter lumen can be comparable to a large-diameter lumen in the vent / filter region. [Figure 63B] Figure 63B shows how a small-diameter lumen can be comparable to a large-diameter lumen in the vent / filter region. [Figure 64] Figure 64 shows the curvature region. [Figure 65] Figure 65 shows one embodiment of a sensing Foley catheter system equipped with a ventilation tube. [Figure 66] Figure 66 shows a sensing Foley catheter system with a separate positive pressure vent tube. [Figure 67] Figure 67 shows a magnified view of the area covered by Figure 66. [Figure 68] Figure 68 shows the engagement regions of various embodiments of a sensing Foley catheter system. [Figure 69] Figure 69 shows the engagement regions of various embodiments of a sensing Foley catheter system. [Figure 70] Figure 70 shows the engagement regions of various embodiments of a sensing Foley catheter system. [Figure 71] Figure 71 shows the engagement regions of various embodiments of a sensing Foley catheter system. [Figure 72] Figure 72 shows the engagement regions of various embodiments of the sensing Foley catheter system. [Figure 73A] Figure 73A shows the engagement regions of various embodiments of a sensing Foley catheter system. [Figure 73B] Figure 73B shows the engagement regions of various embodiments of the sensing Foley catheter system. [Figure 74] Figure 74 shows the engagement regions of various embodiments of a sensing Foley catheter system. [Figure 75A] Figure 75A shows the coverage area of ​​various embodiments of a sensing Foley catheter system. [Figure 75B] Figure 75B shows the engagement regions of various embodiments of the sensing Foley catheter system. [Figure 76] Figure 76 shows the engagement regions of various embodiments of a sensing Foley catheter system. [Figure 77A] Figure 77A shows the coverage area of ​​various embodiments of a sensing Foley catheter system. [Figure 77B] Figure 77B shows the engagement regions of various embodiments of a sensing Foley catheter system. [Figure 78] Figure 78 shows the engagement regions of various embodiments of a sensing Foley catheter system. [Figure 79] Figure 79 shows the engagement regions of various embodiments of a sensing Foley catheter system. [Figure 80A] Figure 80A shows the engagement regions of various embodiments of the sensing Foley catheter system. [Figure 80B] Figure 80B shows the engagement regions of various embodiments of the sensing Foley catheter system. [Figure 81] Figure 81 shows the engagement regions of various embodiments of the sensing Foley catheter system. [Figure 82A] Figure 82A shows the engagement regions of various embodiments of a sensing Foley catheter system. [Figure 82B] Figure 82B shows the engagement regions of various embodiments of a sensing Foley catheter system. [Figure 83] Figure 83 shows the engagement regions of various embodiments of the sensing Foley catheter system. [Figure 84] Figure 84 shows the engagement regions of various embodiments of the sensing Foley catheter system. [Figure 85] Figure 85 shows the engagement regions of various embodiments of a sensing Foley catheter system. [Figure 86] Figure 86 shows the engagement regions of various embodiments of a sensing Foley catheter system. [Figure 87] Figure 87 shows one embodiment of a sensing Foley catheter system equipped with an internal ventilation tube. [Figure 88] Figure 88 shows one embodiment of a sensing Foley catheter system equipped with an internal ventilation tube. [Figure 89] Figure 89 shows one embodiment of a sensing Foley catheter system equipped with an internal vent tube and a positive pressure tube. [Figure 90] Figure 90 shows one embodiment of a sensing Foley catheter system equipped with an internal ventilation tube. [Figure 91] Figure 91 shows one embodiment of a sensing Foley catheter system equipped with an internal ventilation tube. [Figure 92A] Figure 92A shows several embodiments of the drainage lumen. [Figure 92B] Figure 92B shows several embodiments of the drainage tube lumen. [Figure 93A] Figure 93A shows another embodiment of the drainage tube lumen. [Figure 93B] Figure 93B shows another embodiment of the drainage tube lumen. [Figure 93C] Figure 93C shows another embodiment of the drainage lumen. [Figure 93D] Figure 93D shows another embodiment of the drainage lumen. [Figure 93E] Figure 93E shows another embodiment of the drainage tube lumen. [Figure 94A] Figure 94A shows an embodiment of a sensing Foley catheter system in which a pressure sensor is provided on a separate catheter. [Figure 94B] Figure 94B shows an embodiment of a sensing Foley catheter system in which a pressure sensor is provided on a separate catheter. [Figure 94C] Figure 94C shows an embodiment of a sensing Foley catheter system in which a pressure sensor is provided on a separate catheter. [Figure 95A] Figure 95A shows an embodiment of a sensing Foley catheter system equipped with a bubble reduction mechanism. [Figure 95B] Figure 95B shows an embodiment of a sensing Foley catheter system equipped with a bubble reduction mechanism. [Figure 95C] Figure 95C shows an embodiment of a sensing Foley catheter system equipped with a bubble reduction mechanism. [Figure 96A] Figure 96A shows an embodiment of a sensing Foley catheter system equipped with a bubble reduction mechanism. [Figure 96B] Figure 96B shows an embodiment of a sensing Foley catheter system equipped with a bubble reduction mechanism. [Figure 96C] Figure 96C shows an embodiment of a sensing Foley catheter system equipped with a bubble reduction mechanism. [Figure 96D] Figure 96D shows an embodiment of a sensing Foley catheter system equipped with a bubble reduction mechanism. [Figure 97A] Figure 97A shows an embodiment of a sensing Foley catheter system equipped with a bubble reduction mechanism. [Figure 97B] Figure 97B shows an embodiment of a sensing Foley catheter system equipped with a bubble reduction mechanism. [Figure 97C] Figure 97C shows an embodiment of a sensing Foley catheter system equipped with a bubble reduction mechanism. [Figure 97D] Figure 97D shows an embodiment of a sensing Foley catheter system equipped with a bubble reduction mechanism. [Figure 98A] Figure 98A shows an embodiment of a sensing Foley catheter system equipped with a bubble reduction mechanism. [Figure 98B] Figure 98B shows an embodiment of a sensing Foley catheter system equipped with a bubble reduction mechanism. [Figure 98C]Figure 98C shows an embodiment of a sensing Foley catheter system equipped with a bubble reduction mechanism. [Figure 98D] Figure 98D shows an embodiment of a sensing Foley catheter system equipped with a bubble reduction mechanism. [Figure 99A] Figure 99A shows an embodiment of a sensing Foley catheter system equipped with a bubble reduction mechanism. [Figure 99B] Figure 99B shows an embodiment of a sensing Foley catheter system equipped with a bubble reduction mechanism. [Figure 99C] Figure 99C shows an embodiment of a sensing Foley catheter system equipped with a bubble reduction mechanism. [Figure 100A] Figure 100A shows an embodiment of a sensing Foley catheter system equipped with a bubble reduction mechanism. [Figure 100B] Figure 100B shows an embodiment of a sensing Foley catheter system equipped with a bubble reduction mechanism. [Figure 100C] Figure 100C shows an embodiment of a sensing Foley catheter system equipped with a bubble reduction mechanism. [Figure 101A] Figure 101A shows an embodiment of a sensing Foley catheter system equipped with a bubble reduction mechanism. [Figure 101B] Figure 101B shows an embodiment of a sensing Foley catheter system equipped with a bubble reduction mechanism. [Figure 102] Figure 102 shows the pressure waveform and its disappearance using a pressure balloon. [Figure 103] Figure 103 shows sample clinical data illustrating a method for removing noise from cardiac signals using ECG. [Figure 104] Figure 104 shows sample clinical data illustrating stroke volume variation analysis using model waveforms. [Modes for carrying out the invention]

[0027] Herein, preferred embodiments of the present invention will be described in detail. However, alternative embodiments of various features of the apparatus are also possible. Examples of these embodiments are shown below, but the scope of the present invention is not limited to these specific configurations.

[0028] Sensing Foley catheter

[0029] Figure 1 shows several embodiments of a sensitive Foley catheter and its features. The catheter may be understood to have various sections depending on its configuration when inserted into a human subject, such as a proximal portion outside the subject, a central or urethral portion, and a distal or bladder portion.

[0030] Various internal lumens, such as air or fluid lumens communicating with the bladder retention balloon 104 and retention balloon port 118, traverse the length of the catheter. The ureteral lumen has one or more distal openings 106 that are placed in the bladder portion of the catheter and has an opening at the proximal end 114 of the catheter. The ureteral lumen may be connected to a drainage tube that delivers urine to a collection receptacle. The drainage tube may be separate from or integrated with the sensing Foley catheter. In some embodiments, the bladder drainage lumen and distal opening may also function as an infusion conduit through which a drug may be injected, or through which a heating or cooling fluid may be injected. A sample sensor (not shown) or a temperature sensor (not shown) may be placed in the catheter in either the urethral portion or the bladder portion of the catheter. Electrical lead wires or optical fiber lead wires may be arranged inside the lumen to enable communication of sensing signals between a sensor located distal to the catheter and the proximal portion, and may also enable communication with a data processing device or controller.

[0031] An inflatable pressure balloon 108 (or a pressure-sensitive membrane positioned across the opening) may be positioned at or near the distal end of the catheter. Embodiments of the pressure balloon or pressure-sensitive membrane may be understood to have a pressure interface having a distally facing surface exposed to pressure from within the bladder and a proximal facing surface exposed to a proximal fluid column. The pressure balloon or membrane is in fluid communication with a fluid column or lumen that is in fluid communication with the pressure port 116 at or near the proximal end of the catheter. Embodiments of the fluid column (filled with either fluid, liquid, or gas) may have a dedicated lumen or a shared lumen.

[0032] In some embodiments, the temperature sensor may be located at or near the distal end of the catheter. The temperature port 110 may include temperature communication wiring 112 that connects the temperature sensor to a display, connector, and / or controller.

[0033] Figure 1 shows the proximal end of a catheter with multiple separate ports, some or all of which may be integrated into a single port, or integrated into the urinary line leading to the urinary system and / or controller. Other lumens and / or ports may also be present.

[0034] Pressure-referenced physiological parameters that a sensing Foley catheter system may sense and / or determine via a controller based on sensed parameters may include, for example, peritoneal pressure, respiratory rate, heart rate, relative lung tidal volume profile, cardiac output, relative cardiac output, and absolute cardiac stroke volume. Some embodiments of the Foley-type catheter may further be equipped with a temperature sensor, one or more specimen sensors, electrodes, and a pair of light sources and sensors. In such further equipped embodiments, other forms of physiological data can be derived, such as blood pressure, oxygen saturation, pulse oximetry, EKG, and capillary filling pressure.

[0035] Embodiments of a sensing Foley catheter may be capable of sensing one or more clinically relevant parameters, such as those included in the following examples: urinary pH, urinary oxygen content, urinary nitrogen content, respiratory rate, heart rate, perfusion pressure of the bladder or urethral wall, temperature within the bladder or urethra, electrocardiogram via sensors on the bladder wall or urethra, respiratory volume, respiratory pressure, peritoneal pressure, urinary glucose, blood glucose via the urethral and / or bladder mucosa, urinary protein, urinary hemoglobin, and blood pressure. In some embodiments, the catheter may be capable of sensing multiple parameters, while in some embodiments, it may be limited to a smaller number, such as a single parameter for a particular application (e.g., respiratory rate in a patient with dyspnea).

[0036] The technology of this disclosure obtains a high-resolution time-series profile (pressure as a function of time) of peritoneal pressure from within the bladder, which can be converted and processed into individual pressure profiles that can be assigned to specific physiological sources, including peritoneal pressure, respiratory rate, and heart rate. By tracking the pressure profile at a sufficiently fast sampling rate as provided by the technology, the pressure profile can be further decomposed and / or analyzed into relative lung tidal volume, cardiac output, relative cardiac output, and absolute cardiac stroke volume.

[0037] Accordingly, aspects of the present disclosure relate to the fidelity and resolution of pressure signals generated in response to changes in bladder pressure, such changes may reflect intraperitoneal pressure profiles, including cumulative inputs from the physiological sources described above. Aspects of the present technology further relate to fidelity and resolution in the conversion of pressure signals to high-resolution electrical signals. Aspects of the present technology also further relate to processing the entire electrical signal profile, a substitute for the intraperitoneal pressure profile, into component profiles that can be assigned to physiological sources.

[0038] The sensitivity of an inflatable balloon as a pressure sensor is, in part, a function of the pressure difference across the balloon membrane, with respect to the baseline. The balloon is most sensitive to pressure when the baseline pressure difference is near zero. As the baseline pressure difference increases, the sensitivity of the pressure-sensitive balloon decreases. Therefore, the technology of this disclosure provides an automatic priming method that maintains the balloon inflated while minimizing the pressure difference.

[0039] To effectively obtain physiological pressure profiles, these profiles must be sampled at a rate that sufficiently decomposes the intrinsic frequencies of profile changes. This consideration is taught by the Nyquist-Shannon sampling theorem, which states that at least 2B samples / second are needed to decompose an event progressing at a frequency of B cycles / second. As applied to physiological pressure cycles, for example, at a heart rate of 70 beats / min, a sampling rate of at least 140 samples / min is required to effectively obtain this cycle. This relationship forms the basis of aspects of the art of this disclosure that identify sampling rates particularly required to obtain physiological pressure cycles, such as relative lung tidal volume, cardiac output, relative cardiac output, and absolute cardiac stroke volume.

[0040] Embodiments of this technology include a pressure interface which may be represented by a balloon having either a flexible or non-flexible membrane.

[0041] According to embodiments of this technology, expandable pressure balloons may be envisioned in one or more of at least two basic forms: flexible and non-flexible. Flexible balloons, typically similar to conventional party balloons, are formed from or include a flexible membrane. Thus, the surface area of ​​the membrane expands or contracts as a function of the balloon's expansion. The flexibility of the membrane, as a whole, determines various characteristics of the balloon at different levels of expansion. During expansion, if unconstrained, the balloon maintains a substantially constant or preferred shape or form, as determined by the principal axis through which the balloon is formed. The balloon membrane maintains a tension level during expansion from the balloon's minimum mass to its maximum mass. Within the limits of the flexibility of the flexible membrane, the pressure increase during inflation results in a continuous expansion of mass. While balloons generally respond to spatial constraints that their shape may face during expansion or inflation, balloons may be considered partially flexible in that they have a preferred intrinsic shape, and this preference for shape hinders a certain level of shape flexibility or adaptability that may be present in non-flexible balloons.

[0042] In inflexible balloons, an inflatable pressure-sensitive balloon is formed from or includes an inflexible membrane or a substantially inflexible membrane. Therefore, the surface area of ​​the membrane does not expand or contract in accordance with the balloon's expansion / pressure level. Inflexible pressure-sensitive balloons may typically be similar to conventional Mylar® balloons. The lack of membrane flexibility determines, as a whole, the various characteristics of the balloon at different expansion levels. The balloon membrane becomes pliable and has a certain degree of slack as the balloon expands from its minimum mass to near its maximum mass. Expansion of an inflexible balloon occurs by stretching the wrinkles and folds of the membrane outward. Contraction or compression of an inflexible balloon typically occurs by creating wrinkles and folds inward. When an inflexible balloon is fully (or substantially fully) inflated without being confined to space, a preferred or inherent shape is assumed, determined by the external shape of the balloon's membrane or transition. However, in a partially inflated state, the balloon as a whole is highly flexible, adaptable, and can take on a wide range of shapes that may be forced upon it by being confined in space.

[0043] According to embodiments of this technology, expandable pressure-sensitive balloons may also possess at least two basic characteristics: flexibility and inflexibility. In these embodiments, the membrane may comprise flexible and inflexible regions. This hybrid type of balloon behaves as a whole, as derived from the behavioral modes of both flexible and inflexible balloons, as described above. Furthermore, flexible balloons may be formed from a membrane that does not have a uniform composition or thickness. In such embodiments, the degree of flexibility may vary in regions of different thicknesses or compositions, affecting the behavior of these regions during balloon expansion. In yet another embodiment, the flexibility of the membrane may have a directionality or polarity that tends to allow flexibility in one or more directions and does not allow flexibility in one or more directions.

[0044] Embodiments of the sensing Foley catheter feature a device utilizing a very small pressure lumen for air delivery. Pressure readings have been measured using lumen inner diameters of 3 mm, 1 mm, and 0.5 mm. Significant signal degradation was observed as the air lumen diameter decreased from 3 mm to 1 mm and 0.5 mm.

[0045] These data indicate that this embodiment of the pressure conversion system is suitable for use in small-diameter pediatric catheters down to a small size of 4F. Even in this embodiment, the catheter tip has a smaller profile compared to other parts of the catheter, and a consistently small diameter can be achieved even with the addition of a pressure-sensitive balloon. Therefore, the catheter of this invention is uniquely studied for pediatric conditions where a more appropriate and less invasive monitoring method is significantly required. In other embodiments, 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 in its fully inflated state and is used solely for tracking macroscopic trends in IAP. In other embodiments, the retention balloon is inflated only slightly to increase balloon sensitivity to small pressure changes. This embodiment allows for more precise measurement of micro-parameters such as heart rate, relative stroke volume, relative cardiac output, respiratory rate, and relative tidal volume. Smaller pressure lumens also allow for more space within larger catheters for other technologies such as sensors.

[0046] In embodiments of a sensing Foley catheter where 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 to a size sufficient to function as a retention balloon. As a result, the inflation pressure, and possibly the pressure generated by the retention balloon contacting the bladder lining, must be subtracted from the pressure reading. Thus, smaller pressure changes may be tracked, as would be measured by a separate pressure balloon. The offset of the inflation pressure may be determined by measuring the pressure within the retention balloon when it is first inserted into the patient, or by measuring the inflation pressure of the retention balloon outside the patient, or by other means. The retention balloon may be filled with a fluid, air, or any other suitable gas.

[0047] Embodiments of the technology of the present disclosure may include embodiments in which the pressure sensor is a mechanical pressure sensor, such as one using an optical fiber, strain gauge, magnetic, resonant, and / or other preferred technology.

[0048] Figure 2 shows an example of respiratory rate sensing data from a human subject provided by one embodiment of a sensing Foley catheter system. During the test period, the subject performs the following respiratory sequence: (1) Hold breath at the end of exhalation. (2) Valsalva maneuver. (3) Hyperventilation. (4) Valsalva maneuver. (5) Hold breath at the end of exhalation.

[0049] Figure 3 shows a detailed view of the normal respiratory period in a respiratory profile similar to that shown in Figure 2. The pressure curve clearly indicates the respiratory peak, allowing for the determination of the respiratory rate, which in turn allows for the determination of the heart rate peak and, consequently, the heart rate.

[0050] Figure 4 shows an example of sensing data of heart rate and relative cardiac output from a human subject, provided by an embodiment of a sensing Foley catheter system, along with simultaneously and independently measured EKG traces. This graph clearly shows that the heart rate peak measured by the sensing Foley catheter is aligned with the heart rate.

[0051] Figure 5 shows data related to relative cardiac output sensing during human leg-raising exercise, which is demonstrated by an increase in cardiac output due to an increase in heart rate.

[0052] The data shown in Figures 6 and 7 were derived from a study conducted on Yorkshire pigs based on an IACUC-approved protocol. Figure 6 shows an example of 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 study on a pig demonstrating the capability of an embodiment of the sensing Foley catheter system for detecting intraperitoneal hypertension. In this study, the peritoneal cavity was accessed with a 5 mm Tenamian trocar. This trocar was then attached to a 5 L bag of Ringer's lactate solution via a peristaltic pump, and the Ringer's lactate solution was injected at a rate of approximately 1 L per minute. Once a pressure of approximately 20 mmHg was achieved, the fluid flow was interrupted, and there was no further net flow in or out of the cavity.

[0053] Figure 8 shows intra-abdominal pressure, respiratory wave pressure, and cardiac pressure substantially aligned as a two-dimensional plot of pressure (mmHg on a logarithmic scale) versus frequency (Hz). An inverse relationship exists between pressure and frequency, and it can be seen that various physiological pressure-related parameters occupy their own sectors when aligned in this manner. Embodiments of the method of this disclosure allow a single overall time-series pressure profile to be decomposed into individual subprofiles depending on these physiological origins, due to the difference nature of both pressure and / or frequency. Measurements of intra-abdominal pressure may be decomposed in a frequency range of approximately 0 Hz to approximately 0.5 Hz. Measurements of respiratory pressure may be decomposed in a frequency range of approximately 0.25 Hz to approximately 0.75 Hz. Measurements of cardiac pressure may be decomposed in a frequency range of approximately 0.75 Hz to approximately 3.0 Hz. Measurements of intra-abdominal pressure may be decomposed in an amplitude range of approximately 5 mmHg to approximately 30 mmHg. Respiratory pressure measurements may be decomposed within an amplitude range of approximately 0.5 mmHg to approximately 5 mmHg. Cardiac pressure measurements may be decomposed within an amplitude range of approximately 0 mmHg to approximately 0.5 mmHg. The sampling frequency is the frequency at which the pressure measurement is performed, but it is preferably about twice the decomposition frequency. For example, the sampling frequency may be approximately 0 Hz to 1 Hz for intra-abdominal pressure measurements, 0.5 Hz to 1.5 Hz for respiratory pressure measurements, and 1.5 Hz to 6 Hz for cardiac pressure measurements.

[0054] Figure 9 provides a flowchart of an embodiment of a method for monitoring pressure that dynamically arises in the abdominal cavity as a fluctuating frequency and amplitude waveform detected from within the bladder. A high-fidelity pressure profile is generated through a pressure interface and transmitted proximally through a fluid column. Further proximally, a pressure transducer converts the high-fidelity pressure waveform into a high-fidelity electrical signal indicating the pressure frequency and amplitude. The generated high-fidelity electrical signal is then processed by a controller to produce a data subset that can reflect components within the overall pressure profile, such subsets attributable to specific physiological sources, such as peritoneal pressure, respiratory rate, heart rate, relative cardiac output, and patient movement or activity.

[0055] Sensing Foley catheter system

[0056] Figure 10A shows an embodiment of a sensing Foley catheter used in conjunction with an embodiment of an airlock cleaning mechanism and a fluid sampling and analysis system. Both urination and pressure readings are achieved by eliminating or reducing airlocks in the urination line.

[0057] The sensing Foley catheter 1000 is similar to the sensing Foley catheter shown in Figure 1. The sensing Foley catheter is shown in use within the bladder 1014. Some of the ports at the proximal end of the catheter shown in Figure 1 are combined in the embodiment shown in Figure 10A. A urinary drainage tube 1001 is also shown here. The urinary drainage tube may be combined with the sensing Foley catheter or may be a separate component. The urinary drainage tube 1001 and / or the sensing Foley catheter may also include a venting port 1016, or the venting port 1001 may 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 comprises a base / controller 1018, a fluid collection bag 1020, and a container or cassette 1022. The combination of the sensing Foley catheter 1000, the urinary drainage tube 1001, and the airlock cleaning mechanism and fluid sampling and analysis system 1002 is also referred to here as the sensing Foley catheter system. The sensing Foley catheter, urinary drainage line, and container / cassette may be disposable or may be sold as a unit. This disposable assembly is shown in Figure 10C, and includes the sensing Foley catheter 1000, the urinary drainage tube 1001 (including the venting section), and the container / cassette 1022.

[0058] The vent section 1016 may comprise one or more vents 1016 and a urine sampling port 1004. In this embodiment, the vents 1006 are preferably made of a membrane that allows gas permeation but not liquid permeation, such as a hydrophobic membrane. Examples of such exemplary vents include PTFE (polytetrafluoroethylene), ePTFE (expanded PTFE), or Versapor® (available from Pall Corporation of Port Washington, NY), or a membrane, but other materials may be used. The vents may allow air to enter the system when negative pressure is applied to the drainage tube and to exit the system when positive pressure is generated by an airlock in the drainage line. Such a mechanism prevents, for example, trauma due to aspiration on the bladder wall. The vents 1006 may incorporate a one-way valve to prevent air from leaving or entering the drainage line. In a preferred embodiment, a one-way valve is used to allow air into the drainage line through the vent 1006 while preventing air from leaving the drainage line. Thus, the valve also prevents urine from coming into contact with the vent 1006.

[0059] The urinary drainage tube 1001 may comprise several lumens, including a pressure lumen 1010, a temperature lumen 1008, and a ureteral lumen 1012. The pressure lumen 1010 is in fluid communication with a pressure-sensitive balloon 108 and a pressure transducer interface 1026 in the controller 1018. The temperature lumen 1008 is in communication with a temperature sensor (not shown) in a sensitive Foley catheter and also with a temperature connector 1024 in the controller. The ureteral lumen 1012 is in fluid communication with one or more openings 106 and a urine container or cassette 1022.

[0060] The disposable measuring tube, collection tube, chamber, or cassette component 1022 is designed to fit within a cassette mount, base, or controller 1018 and interface with the controller components. The controller pump interface (behind the cassette pump interface 1148) connects to the pump 1134 and the cassette pump interface 1148 on the disposable cassette component. This pump may be designed to create a vacuum within the cassette component, which is then transferred to the urine discharge lumen in the discharge line. The collection tube / cassette is preferably rigid to maintain a constant volume when the pump applies negative pressure. The level of negative pressure applied may be monitored by a pressure sensor. During airlock cleaning, the pressure follows the characteristic curve shown in Figure 59. As suction is applied, the pressure decreases and eventually reaches an inflection point when the urine meniscus passes the lowest point in the drainage piping. At this point, less suction is required to continue cleaning the airlock, and once the airlock is completely clean, the pump power can be reduced to minimize the amount of suction transmitted to the bladder. For example, in the case of a larger tube that does not have this pressure-sensitive feature, once the airlock is clean, a substantial negative pressure will be transmitted to the bladder before time has passed for the tube to equilibrium with the atmosphere. The controller pressure interface (rear of the cassette pressure interface 1150) connects the cassette pressure interface 1150 to a pressure measuring device, such as a pressure transducer. The pressure measuring device is designed to measure the amount of urine or other fluid based on the pressure applied to the pressure measuring device, which may also be a pressure transducer. The ultrasonic transducer interface 1130 also measures urine volume. Ultrasonic measurement can be used in conjunction with pressure measurement or to determine the amount of urine or other fluid discharged. The active pinch valve 1132 is designed to connect to the cassette's outflow piping. The pinch valve controls the emptying of the cassette tube, and is controlled by the controller to release urine / fluid when the amount of urine in the cassette reaches a specific level, as determined by pressure and / or ultrasonic measurement.The amount of urine in the cassette is measured, and when the urine reaches a specific amount, the urine is transferred to the urine collection bag 1020 via a pinch valve and emptied. For example, the cassette may be emptied when the amount of urine in the cassette reaches approximately 50 ml. Alternatively, the cassette may be emptied when the amount of urine in the cassette reaches approximately 40 ml. Alternatively, the cassette may be emptied when the amount of urine in the cassette reaches approximately 30 ml. Alternatively, the cassette may be emptied when the amount of urine in the cassette reaches approximately 20 ml. Alternatively, the cassette may be emptied when the amount of urine in the cassette reaches approximately 10 ml. In this way, the amount of urine can be accurately measured over time.

[0061] Alternatively, the controller may use the set time while emptying the cassette to measure the amount of urine in the cassette just before emptying. Alternatively, the controller may empty the cassette in response to an event such as airlock removal triggered by pump startup. For example, the controller may set a periodic airlock cleaning cycle prior to emptying the cassette and prior to measuring the amount of urine in the cassette.

[0062] For example, the controller may control the pinch valve to empty the container / cassette when the urine volume reaches approximately 50 ml. Alternatively, the controller may control the pinch valve to empty the container / cassette hourly after measuring the urine volume in the cassette. Alternatively, the controller may control the pinch valve to empty the container / cassette during or after a urination event, such as pump operation. Alternatively, the controller may use a combination of these triggers to control the pinch valve to empty the container / cassette.

[0063] In addition to pressure and / or ultrasonic techniques, or in place thereof, other techniques, including pressure, resistance, volume, ultrasound, or optics-based techniques, may be used to measure urine volume. To improve the accuracy of volume measurement, more than one technique may be used, and these measurements may be compared with one another. More than one volume measurement performed by one or more techniques may be used for redundancy or backup, and may be used together to obtain a more accurate urine volume measurement.

[0064] The bed hooks 1116 are for attaching the controller to a bed or other device as needed. They can also be used to attach the controller to mobile devices for patient transport. The collection bag hooks / holes 1102 are for mounting a drainage bag from which urine / fluid is ultimately collected after passing through the pinch valve. The collection bag hooks 1102 may be designed to perform strain measurement so that the weight of the fluid in the bag can be determined, thereby providing another method for determining the amount of fluid in the bag. For example, a piezoelectric transducer may be used. The controller may also use specific gravity determination so that useful quantity measurements based on weight and specific gravity can be determined.

[0065] Screen 1110 is for displaying information including the current urine / fluid volume and system status. Screen 1110 may be a touchscreen and may receive input including settings, screen display changes, and menu changes. Pressure port 1026 connects to the bladder pressure line 1010 and is used to measure bladder pressure when a sensing Foley catheter is used. Alternatively, the pressure port may be located in the cassette mount below the cassette 1022 or elsewhere in the controller / base. Temperature input port 1024 connects to a thermistor / temperature sensor that measures body temperature via the lumen 1008 and via a sensing Foley catheter or by other means. Temperature output port 1122 is for transmitting any temperature measurement to an external device and / or monitor. Adapter port 1124 is for adapting the controller to other devices, such as an RFID adapter. This can be used to activate any additional / advanced features, such as IAP, respiratory rate, heart rate, cardiac output, or any other parameters that may be measured by a sensing Foley catheter. This activates additional parameters, and payment is made by the hospital only when the information is desired. The activation of advanced features may be controlled, for example, using different disposable components. Alternatively, advanced features may be activated by a software upgrade, purchased as part of a disposable component or separately. The software upgrade may be delivered wirelessly, via a USB dongle, a microSD card, an EPROM card, or other suitable technology. Patient data for each patient and / or patient population may also be stored by the controller. Patient data may be stored in memory, USB, a microSD card, an EPROM card, a hard drive, or elsewhere. Patient data may be transferred wirelessly or via wired connection to other storage devices, such as a server on the Internet or an intranet. Patient data may be anonymized. Patient data, such as patient IDs, may be stored in an RFID adapter so that data specific to a particular patient is recognized by the controller and associated with the disposable component used for the patient.

[0066] The power LED / indicator 1114 indicates whether the power is on or off. The error LED / indicator 1112 indicates whether or not an error has occurred in the system. Details of the error can be displayed on screen 1110, but indicator 1112 warns the user that an error is present. The indicator may also incorporate audible or other warnings.

[0067] Port 1108 is used for connecting to other devices, such as for downloading, uploading, software upgrades, and integration with EMR (Electronic Medical Record) systems. Port 1108 may be a USB port or other suitable port. SD port 1106 is used for data downloads. Power port 1104 connects the controller to a wall or other power source and supplies power to the controller.

[0068] The urine / fluid drainage bag 1020 is equipped with one-way valves 1136 connected to the overflow pipe 1138 and the outflow pipe 1140 to prevent urine / fluid from leaving the drainage bag after it has been collected. These valves also prevent air from entering the collection tube 1022 when the pump 1134 is creating a vacuum, so that a vacuum acts on the drainage pipe but not on the bag. In a preferred embodiment, one valve is used for both the overflow pipe and the outflow pipe. The drainage bag 1020 is detachably attached to the controller 1018 by incorporating a hook / hole 1102. The vent 1142 may be hydrophobic or other, and allows air or gas to escape from the drainage bag but not fluid. This prevents excess air and, possibly pressure, from forming inside the bag, allowing the drainage bag to be filled efficiently. The graduated markings 1144 indicate a somewhat rough measurement of the amount of fluid collected in the bag. The fluid / urine bag may be emptied using the outflow valve 1146. The valve is preferably easily operated by one person. When the collection bag hook 1102 is designed as a strain measuring element, an audible alarm may be emitted when the bag has reached full capacity and needs to be emptied. The alarm may audibly indicate that excessive force is being unnecessarily applied to the bag, for example, if the bag is being pulled or caught on an obstacle as the patient moves.

[0069] 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 outlet valve may be made of PVC, PC, or other suitable material.

[0070] Pressure readings from a sensing Foley catheter may be used to trigger the pump, and by extension, to empty the drainage tubing. For example, when the pressure sensed in the bladder exceeds a preset number, the pump may engage, causing urine to move more quickly through the drainage tubing.

[0071] The controller / base and / or container / cassette may be equipped with an accelerometer or other sensor to determine whether the controller / cassette is horizontal. If the controller / cassette is not horizontal, an audible alarm may sound. Alternatively, the urine volume measurement may be adjusted to indicate different angles within the system.

[0072] The bottom of the urine container inside the cassette may have a rounded rim, or it may be configured so that when the pinch valve is opened, the urine is completely emptied from the cassette.

[0073] Figure 10B is a detailed view of the airlock cleaning mechanism and fluid sampling and analysis system 1002. Screen 1110 displays a user interface including patient parameters and a touchscreen or other control function. The heart rate area 1152 shows the patient's heart rate as determined by the controller based on intravesical pressure measurements sensed by a sensitive Foley catheter. The respiratory rate area 1154 shows the patient's respiratory rate as determined by the controller based on intravesical pressure measurements sensed by a sensitive Foley catheter. The core temperature area 1156 shows the patient's core temperature as sensed by a sensitive Foley catheter or other temperature sensor. The urine volume area 1158 shows the patient's current and / or average urine volume as determined by the controller based on urine volume measurements taken by a pressure measuring device connected to the pressure interface 1150 and / or ultrasonic transducer interface 1130. The sepsis indicator area 1160 indicates the likelihood of sepsis in the patient as determined by the controller based on one or more collected and / or calculated patient parameters. For example, temperature, abnormal heart rate, abnormal respiratory rate, and / or urine output, and other factors may be considered in determining the risk of sepsis. Trends in these parameters may also be used in risk assessment. For example, decreased urine output, increased heart rate, and elevated or decreased core temperature may be indicators of sepsis.

[0074] In addition to, or as an alternative to, sepsis indicators, other risk assessments may be determined and displayed by the controller. These include acute kidney injury, urinary tract infection, intra-abdominal hypertension, abdominal compartment syndrome, infection risk, sepsis, ARDS (acute respiratory distress syndrome), and other risk assessments. For example, Figure 58A shows sample risk algorithms for acute kidney injury and urinary tract infection. Figure 58B shows sample risk algorithms for acute kidney injury, sepsis, and acute respiratory distress syndrome. Measured urine parameters may include conductance, specific gravity, urine volume, presence or absence of infectious bacteria, leukocyte count, oxygen pressure, and others.

[0075] The graphic indicator 1162 displays historical data from any of these areas. For example, the user may switch the graphic display by touching the screen to show urine volume, temperature, heart rate, respiratory rate, sepsis index, risk of acute injury, urinary tract infection, intra-abdominal hypertension, abdominal compartment syndrome, infection risk, and other patient history, or any other relevant parameters. The historical time frame may be continuous, daily, hourly, or any period set by the user. Risk factors that are outside the range or have increased risk may be automatically indicated in this or elsewhere on the display. Warnings and / or ranges may be set by the user and may include absolute values ​​and trends over time. For example, a core temperature increase of more than 2 degrees over a particular time frame may be visually displayed or an audible warning may be given.

[0076] Figure 11 shows one embodiment of a sensing-type Foley catheter system (including an airlock cleaning mechanism, fluid drainage, and collection / analysis system / controller) similar to that shown in Figure 10A, in which the vent 1180 is located on the controller 1018 or container / cassette 1022 instead of on the vent latch 1182. In this embodiment, the vent 1180 is in fluid communication with the ureteral lumen 1012 via a vent lumen 1184 that fluidly connects to the ureteral lumen 1012 at the latch 1182. In this embodiment, the design of the latch is simplified, and the drainage piping has an additional lumen compared to the embodiment shown in Figure 10A. The vent may be located anywhere in the system, and the fluid contact surface with the ureteral lumen may also be located anywhere in the system.

[0077] Figure 12 shows an embodiment of a sensing Foley catheter system similar to that shown in Figure 10A, but without a pressure balloon, in contrast to the system shown in Figure 10A. Instead, pressure is measured inside the bladder via a ureteral lumen (or other lumen) within the sensing Foley catheter. In this embodiment, the pressure lumen 1202 is connected to a vent 1204 or to another part of the system outside the patient, and is at least periodically fluidly connected to the catheter's drainage / ureteral lumen. In this embodiment, the sensing Foley catheter system may be used with any standard Foley catheter. Any embodiment of the sensing Foley catheter system may be used with a standard Foley catheter. The system shown in Figure 12 may also be used with a standard Foley catheter without the pressure lumen 1202 if pressure measurement inside the bladder is not desired.

[0078] Figure 13 shows an embodiment of a sensing Foley catheter system similar to that shown in Figure 12. In this embodiment, a valve 1302 may be used to periodically close the pressure lumen 1202 to the ureteral lumen. The valve can be opened by the controller or manually when pressure measurement is performed and closed again by the controller or manually when bladder pressure reading is not required.

[0079] Figures 10A, 10B, 11, and 12 show embodiments of a sensing Foley catheter system equipped with a vent near the patient end of the drainage tube to allow air to enter the drainage tube when negative pressure is generated by either a siphon or pump mechanism within the drainage tube, or both. Without the vent / filter, such negative pressure can cause aspiration-induced trauma, such as trauma to the inner mucosal layer of the bladder. Note that this embodiment differs from a device in which the vent repels air but prevents it from entering the drainage tube.

[0080] The drainage lumen preferably has an inner diameter of less than approximately 0.25 inches so that the fluid within the lumen maintains contact with the surrounding area, forming a seal and advancing the fluid when the pump mechanism is in operation. Multiple drainage lumens may be provided to prevent blockage of the flow in the event of a malfunction of the pump mechanism. In these embodiments, the drainage lumens are usually preferably empty, which may require the continuous operation of the pump mechanism. Alternatively, the pump mechanism may be operated before volume measurement to ensure that all fluid is drained, thereby reducing the power requirements of the device.

[0081] Some embodiments of a sensing Foley catheter system include detecting a pressure increase in the drainage line when the pressure in the body tissue is 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 tissue.

[0082] In one embodiment, the vent has an airflow resistance greater than the resistance to the flow of fluid from the patient, so that any fluid generation within the patient is pushed into the drainage line before air enters through the vent. For example, in the case of urination, as long as the airflow resistance through the vent is greater than the resistance to the urine flowing through the patient's catheter, the full bladder will be emptied into the drainage line before air enters through the vent. However, it is preferable that the vent has the smallest possible resistance to airflow while satisfying this requirement in order to minimize trauma by aspiration.

[0083] In other embodiments, the vent has very little resistance to airflow so that the bladder is further protected from aspiration, and the controller pump is operated to clean the airlock at more frequent intervals, for example every minute, every 5 minutes, or every 10 minutes, to maintain a clean state of urine from the drainage line. The pump may continue to operate until it is detected that no more urine has been discharged, which indicates that the bladder is completely empty. Alternatively, the pump may operate for a set period of time, for example, about 30 seconds, about 1 minute, about 3 minutes, about 5 minutes, or about 10 minutes.

[0084] The pump mechanism used may include, but is not limited to, any suitable pump, such as a peristaltic pump, diaphragm pump, impeller pump, centrifugal pump, or any other suitable pump. The pump may be powered by a wall outlet, battery, manual labor, or any other suitable power source. In some embodiments, the vacuum is in the range of about 0 to -50 mmHg. Negative pressure may be supplied alternatively by a wall vacuum, which is often present in the patient's room. The pump mechanism may include a peristaltic-like pump or suction applied directly to the collection tube. The pump may be located on the patient side of the drainage container, or it is preferable that the pump be located on the non-patient side of the drainage container / cassette so that the container is between the patient and the pump. For the pump to function properly, it is preferable that it be able to generate a negative pressure equal to the highest liquid column height in the drainage tube. This may be half the length of the drainage tube. If the urinary drainage tube has a maximum length of 60 in, the required maximum negative pressure would be approximately 30 in H2O, or 56 mmHg.

[0085] Other techniques may be used to expel urine through piping and / or systems that include pulsatile mechanical stimulation, vibratory acoustic stimulation, thermal stimulation, vibration stimulation, pinching stimulation, rotational stimulation, or electromagnetic stimulation to produce at least one of the movements between the drainage line and the bodily fluid inside. In some embodiments, the rotational stimulation comprises sequentially pressing on multiple lumens such that not all lumens are pressed at the same time.

[0086] In other embodiments, the airlock is removed by a crushable drainage tube provided in a more rigid, torsion-resistant tube. Figure 14A shows such an embodiment in its uncrushed form. The inner crushable drainage tube 1402 is inside the outer torsion-resistant tube 1404. Figure 14B shows an embodiment in which the inner crushable tube is crushed. The drainage tube is periodically crushed by applying positive pressure to the space between the crushable tube and the torsion-resistant tube, or by applying negative pressure inside the crushable tube. Crushing the drainage tube pushes urine from the patient into the collection tube.

[0087] In other embodiments, the drainage tube lumen cleaning mechanism comprises a tube having an inner diameter of less than approximately 0.25 inches to prevent air pockets from moving along the length of the tube. This is made possible by surface tension within the smaller tube, which prevents fluid movement when one end of the tube is closed to the periphery (as in the case of the bladder). Thus, the drainage tube is always kept filled with urine, and for every amount of urine produced, an equal amount of urine must exit the drainage tube because urine is incompressible. In other embodiments, the inner diameter is less than 0.125 inches. In other embodiments, the drainage tube described above acts as a siphon, creating a small, safe amount of vacuum in the bladder. Alternatively, a small lumen drainage tube periodically introduces air into the tube lumen through a vent / valve. Negative pressure generated by a pump may facilitate this. Urine is encouraged to flow continuously into the collection container by the negative pressure generated by the pump, thereby preventing airlock.

[0088] The use of smaller diameter tubing also results in less residual urine in the drainage tube compared to conventional methods. Less residual urine is preferable as it allows for faster movement of urine from the patient's bladder to the collection tube. This transport speed is important for measuring urine that is produced more recently. This is especially important for patients with low urine production rates, as it takes more time to transport urine from the bladder to the collection tube. For example, for a patient producing only 10 mL of urine per hour in a standard drainage tube (with approximately 40 mL of residual urine), the measurement of urine in the collection tube would be delayed by 4 hours from true urine production. On the other hand, with smaller tubing (e.g., tubing with approximately 5 mL of residual urine), the delay would be only 30 minutes from true production. In some embodiments utilizing smaller diameter tubing, a pump to create negative pressure in the drainage line is not required, with or without a vent / valve.

[0089] Figure 15 shows one embodiment of a device well suited for draining from 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 fluid 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. The fluid is drained from the patient through a drainage tube lumen 1585, which is connected to a collection tube 1582. Drainage is assisted by drawing a negative pressure on the collection tube 1582, for example by attaching a suction tube 1583 to a suction section in the hospital wall. Suction may also be applied by other means, such as a pump as disclosed elsewhere herein. Air enters the drainage tube lumen through a valve 1584, which has a crack pressure equal to the desired negative pressure. By selecting the correct crack pressure (e.g., -15 to 0 mmHg or -10 mmHg), the pressure applied to the patient will be maintained at this pressure, as long as the suction / pump in the hospital wall can produce sufficient suction in the collection tube 1582. The drainage lumen used for discharge from the chest tube should be as large as possible while maintaining a siphon. Suitable inner diameters include, but are not limited to, about 1 / 4”, about 5 / 16”, or about 3 / 8”.

[0090] Figure 16 shows another embodiment of a device well suited for draining from a chest tube or other drainage tube that applies a constant negative pressure to a patient. Fluid is drained from the patient through a drainage tube lumen 1688, and negative pressure is applied using a pump mechanism 1686. A pressure sensor 1687 measures the pressure applied to the patient by being located in the drainage tube at the patient end. The measurement obtained by the sensor 1687 is sent back to a controller that controls the pump mechanism 1686, which adjusts the pressure generated by the pump mechanism 1686 to maintain the pressure at the sensor 1687 (and the patient) at a desired level. The pressure sensor 1687 may also be located elsewhere in the system. This sensor may also be used for active monitoring of the pressure at the patient end of the tube to provide the clinician with information about the level of suction being applied. Figure 16 shows the pump on the patient side of the drainage container, but this pump may alternatively be on the other side of the drainage container, with the container between the patient and the pump.

[0091] In another embodiment of the present invention used for drainage from a chest tube, the amount of fluid drained is measured to inform a clinician about the drainage status of the chest tube. This measurement can be achieved by any preferred means, in particular by those described for measuring urine volume.

[0092] In addition to removing airlocks, some of the airlock cleaning designs detailed above have been shown to effectively clean sediment and blood clots from the urinary line. These issues are a troubling problem in current monitoring techniques for urinary tubing, particularly in smaller lumen drainage tubes and drainage bags, and the present invention represents an improvement over conventional methods by automating the cleaning of these debris and clots that obstruct drainage. This feature is particularly useful when used with pressure sensing in the balloon at the tip of the Foley or in fluid communication with the bladder. This allows for monitoring of pressure and vacuum within the bladder, enabling more aggressive pumping action based on actual bladder pressure until the clot / obstruction is cleaned. Without this pressure / vacuum sensing, pumping action of the fluid within the drainage tube can expose the bladder mucosa to excessive vacuum, potentially leading to clinical complications in the bladder, such as aspiration trauma.

[0093] In another embodiment, as shown in Figure 17, the gas sampling lumen 1790 extends along the length of the drainage tube to a filter 1791 that is permeable to gas but impermeable to liquid, maintaining contact with the urine, with its meniscus 1792 further from the patient than the filter. When measurement of oxygen, carbon dioxide, or any other gas is required, the air in 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 embodiments of devices that supply air to the drainage line, such as those shown in Figures 10 to 16.

[0094] As shown in Figure 18, the active ventilation system comprises an air vent 1802, a drainage line 1804, a collection tube 1806, and a pump 1808. The vent side of the drainage line is connected to the patient. In one embodiment, the fluid to be drained is urine, which is connected to a urinary catheter. The fluid flows from the patient through the drainage line and is collected in the collection tube. The pump in this embodiment does not act directly on the drainage line but creates a vacuum on the collection tube. This pump promotes drainage by creating negative pressure on the collection tube, which pushes the fluid through the drainage line. When the pump applies negative pressure, the collection tube is preferably rigid in order to maintain a constant flow rate. The vent on the patient side of the drainage tube is preferably a vent that allows gas (preferably air) to pass through but prevents liquid from passing through. Thus, this vent prevents substantial negative pressure from being applied to the patient by allowing ambient air into the system. Such a mechanism prevents, for example, trauma to the bladder wall due to aspiration.

[0095] The pump in this system includes, but is not limited to, a peristaltic pump, a diaphragm pump, or a centrifugal pump; any pump suitable for pumping gases can be used. Preferably, the pump must be able to generate a negative pressure equal to the maximum liquid column height in the drainage tube in order to function properly. This may be half the length of the drainage tube. If the drainage tube has a maximum length of 60 in, the required maximum negative pressure would be approximately 30 in H2O, or 56 mmHg.

[0096] As shown in Figure 19, the active ventilation system for draining bodily fluids may have additional vents. One such vent, vent 1962, may be positioned in the manner of the collection tube and allow air to escape from the collection tube. This prevents pressure increases when new fluid enters the tube by offsetting each amount of fluid entering the system with an equal amount of air exiting the system. Another such vent, vent 1964, may be positioned between the collection tube and the pump. This vent allows gas (preferably air) to pass through but not liquid to prevent bacteria or viruses from entering or leaving the collection tube and drainage tube. This vent is preferably sterile grade, meaning that the air passing through it is considered sterile. Vents (not shown here) may or may not be present at the patient end of the drainage line.

[0097] As shown in Figure 20, pressure offsetting may be achieved by a single vent on the collection tube. In this case, the vent, i.e., vent 2072, may be located between the collection tube and the pump as described above, but an additional valve 2074 releases air from the collection tube in the presence of positive pressure. This valve is preferably a one-way valve that releases air from the system but does not introduce air into the system. When the pump is operating, the one-way valve must close, drawing air out of the collection tube, thereby creating negative pressure in the collection and facilitating the flow of fluid through the drainage line. The vent may or may not be located at the patient end of the drainage line (not shown here).

[0098] Infection detection

[0099] Figure 21 shows one embodiment of a collection tube, 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 / optical / Raman spectroscopy. The cassette 2100 comprises a container wall 2102, which is preferably rigid. Urine 2106 is collected in the cassette. If urine is collected too quickly or there is any obstruction when emptying the cassette, an overflow area 2104 will allow the excess urine to be discharged from the cassette. The cassette 2100 may comprise an optically transparent section 2110, which is preferably incorporated into the outer wall of the cassette, and a reflector section 2112, which is preferably provided on or incorporated into the inner wall of the cassette. Here, “optically transparent” means that light at the required analytical wavelength can pass through the optically transparent section. The optically transparent section is preferably made of a material that can transmit UV light, such as polymethyl methacrylate, polystyrene, acrylic, or quartz. The thickness of the wall portion may need to be thin enough to allow the appropriate UV wavelength to pass through the optically transparent portion. For example, the thickness of the optically transparent portion may be about 0.5 mm to about 0.7 mm. Alternatively, the thickness of the optically transparent portion may be about 0.5 mm to about 0.6 mm. Alternatively, the thickness of the optically transparent portion may be about 0.6 mm to about 0.7 mm. Alternatively, the thickness of the optically transparent portion may be less than about 0.7 mm.

[0100] The UV / light emitter / receiver 2108 transmits UV or other wavelength light at an appropriate wavelength through the urine in the cassette to the reflector 2112 in the cassette via the optically transparent section 2110. The UV / light emitter / receiver may be incorporated into or connected to the controller component of the sensing Foley catheter system. This light is reflected back to the UV / light receiver, which transmits the collected data to the controller for signal analysis. More than one UV / light wavelength may be analyzed simultaneously or sequentially. In addition to light within the UV range, light outside the UV range may be used. The physical volume of urine between light emission and reception is preferably maximized to obtain a stronger signal that reflects the concentration of one or more substances in the urine. The emitter / receiver may be arranged as shown in Figure 21, or may be located in other areas of the cassette. The receiver may be located in a different location than the emitter, and the reflector may or may not be present as required. Because the urine in the cassette is frequently emptied, UV / light absorption measurements can be collected over time, allowing for the tracking of increases or decreases in the levels of one or more substances in the urine over time, essentially in real time or near real time. This is particularly important in rapid infection identification, including urinary tract infections and catheter-associated urinary tract infections (CAUTIs). UV / light detection may also be performed at other locations within the sensing Foley catheter system, including drainage tubing, separate sampling areas, etc.

[0101] Infection may be identified by analyzing urine for bacteria, red blood cells, and plasma and / or white blood cells using UV / optical spectroscopy. Figure 22 shows the various light absorption wavelengths of E. coli, red blood cells, and plasma in urine. The presence of plasma / white blood cells and / or bacteria in urine is an indicator of infection. The presence of red blood cells may not indicate infection. Therefore, it is desirable to distinguish between red blood cells and bacteria / plasma / white blood cells in urine. The characteristic spectroscopic properties of red blood cells are significantly different from those of either bacteria or plasma / white blood cells at a wavelength of approximately 414 nm, so the signal for red blood cells can be separated from that of bacteria and / or plasma / white blood cells, and infection can be identified by analyzing the absorption of light at this wavelength. The characteristic properties of plasma and bacteria are different from each other at wavelengths of 260 nm and 280 nm, so these wavelengths can be used to distinguish between crystals and bacteria. However, it is highly likely that both plasma and bacteria will be present during infection.

[0102] Other wavelengths and other techniques may be used to detect various substances in urine or any collected / excreted bodily fluids. UV / light absorption may be used to detect turbidity. Dyes, drugs, or reactive substances may also be introduced into the system or coated on the inner surface of the system, cassette, etc., to react with substances in the urine to aid in analysis. Any type of sensor may be used to sense any substance or amount of urine collected intermittently or continuously in real time. For example, a sensor that detects magnesium in urine may be used to diagnose preeclampsia or eclampsia. A lactate sensor may 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 enzyme lactate sensors. For example, lactate sensors are disclosed in 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. FrontBiosci. 2004 Sep1;9:3384~91), both of which may be used, although their entirety is incorporated by reference.

[0103] Drugs or drug residues may be detected in the collected urine using appropriate sensors. Other substances or properties of the collected urine that may be detected include color, clarity, odor, specific gravity, osmolality, pH, proteins, glucose, creatinine, nitrites, leukocyte esterases (WBC esterases), ketones, red or white blood cells, casts, crystals, bacteria, yeast cells, parasites, squamous epithelium, etc.

[0104] CAUTI or infection may be identified and / or reduced by several methods, including analyzing urine using spectroscopy, wavelength analysis, etc., early identification of contamination, reducing trauma to the bladder caused by aspiration, reducing urine retention in the bladder, reducing the presence of bacteria or microorganisms by using antimicrobial coatings or implantation materials such as silver or other materials, improving the accuracy of bladder pressure measurement by reducing bladder aspiration, and improving the accuracy of urine volume measurement by reducing airlocks and bladder aspiration in the system. Pressure spikes caused by bladder aspiration may be defined by pressure readings below approximately -20 mmHg. Alternatively, pressure spikes caused by bladder aspiration may be defined by pressure readings below approximately -10 mmHg to approximately -20 mmHg. Alternatively, pressure spikes caused by bladder aspiration may be defined by pressure readings below approximately -10 mmHg.

[0105] Figure 23 shows one embodiment of a cassette including a baffle or flap 2302. This baffle / flap is intended to prevent urine from being carried along the inner wall of the cassette, as indicated by the dotted arrow. The baffle will prevent urine from being carried beyond the point of the baffle so that it falls back into the measuring container.

[0106] Priming

[0107] One aspect of the technique of this disclosure, particularly advantageous for achieving high-resolution signals in which pressure profiles from specific physiological sources (such as peritoneal pressure, respiratory rate, and heart rate, relative pulmonary tidal volume, cardiac output, relative cardiac output, and absolute cardiac stroke volume) may be monitored, relates to adjusting and maintaining a pressure balance on either side of the pressure interface represented by the membrane of a pressure-sensitive balloon. This pressure balance may be referred to as a pressure difference. In some embodiments, a preferred pressure difference is zero or about zero. In some embodiments, the preferred pressure difference may be a different value. The pressure acting on the outer surface of the balloon (facing the inner surface of the bladder) is subject to variation according to the patient's physiology. The pressure on the inner surface of the balloon (fluid-communicating with the fluid column) is subject to degradation due to fluid leakage and incomplete sealing.

[0108] During the initial insertion of a sensing Foley catheter, external pressure is typically applied to the fluid column, counteracting the pressure interface to a first approximation of the pressure acting on the pressure interface from within the bladder. The pressure signal measured across the pressure interface has its maximum amplitude when the pressure difference is approximately zero. Therefore, the amplitude of the pressure signal can be used to adjust the pressure applied from the fluid column against the pressure interface. This process of applying an appropriate amount of pressure to the interface may be called priming the fluid column or priming the balloon. However, as mentioned above, the pressure on either side of the pressure interface may change, so the fluid column may need to be reprimed or readjusted from time to time. The need for repriming can be monitored by testing small pressure changes to achieve the maximum amplitude of the pressure signal profile. Alternatively, priming can be automatically generated periodically via a controller.

[0109] Embodiments of the systems and methods of this disclosure include automatic pressure regulation by a controller. The regulation system can detect the optimal target pressure and volume for inflating the balloon by monitoring the sensed pressure signal and, if necessary, adding or removing amounts of air or fluid. For example, during catheter insertion, a pressure regulation circuit regulating the balloon volume and pressure may inflate the balloon until it detects a pressure ratio of the physiological source. In sensing this ratio, the pressure regulation controller may, in a routine or programmed sequence, add or remove small amounts of air until the amplitude of the sensed wave is maximized. A control feedback loop between the optimized and regulated pressure (which manifests as balloon pressure and volume) and the sensed physiological pressure profile is continuous and / or iterative as needed to ensure high-fidelity measurement of physiological data. In some embodiments, automatic pressure regulation may be performed in an obvious background while physiological data is being transmitted and displayed. In other embodiments, the system may suspend the transmission of physiological data during the pressure regulation sequence.

[0110] Embodiments of the technology of this disclosure include a gas delivery system capable of delivering gas during priming operations, thereby enabling the application of pressure to a fluid column proximal to the proximal opposing surface of a pressure interface. The source of the gas, such as compressed air or liquid, is held in a storage tank. Using CO2 as an example, the CO2 is controlledly released from the storage tank through a pressure regulator capable of reducing the pressure in the tank (e.g., a pressure of about 850 psi) to a range of about 1 psi to about 2 psi. The released gas passes through a filter and a pressure relief valve set to about 2.5 psi. The pressure relief valve is a safety feature that prevents gas flow at levels above 2.5 psi in the event of a malfunction in the upstream regulator. The CO2 that exits the pressure relief valve then passes through a solenoid-controlled filling valve, enters a catheter line, and is finally filled into a balloon equipped with a pressure-sensitive interface. The pressure in the balloon is raised to a high level of 30 mmHg, at which point a first solenoid-controlled valve closes. The second solenoid control valve is distal to the first valve and acts as a vent valve capable of releasing pressure from the catheter to a target pressure. Alternatively, the vent valve may operate until the balloon is optimally primed and a respiratory waveform is detected prior to valve closure. The vent valve may be subject to stochastic control based on voltage or pulse width modulation (PWM) operation, thereby reducing the venting rate sufficiently so that the target pressure is achieved and the valve can be closed prior to overshoot. Alternatively, the balloon may be filled with room air using peristalsis or other air pumps.

[0111] Figure 24 shows a graph illustrating a pressure balloon priming method in several embodiments. Here, a burst of a small amount of fluid (roughly about 0.3 cc) is applied to a pressure-sensitive balloon, and the pressure inside the balloon is measured. The burst of small fluid is introduced until the measured pressure inside the balloon settles to a stable pressure 2401. This transition is shown at the inflection point 2402. The burst of volume is introduced beyond this point until the measured pressure begins to increase rapidly (for example, when the slope of the curve 2404 exceeds approximately 2 mmHg / 10m). This inflection point is shown at 2406. At this point, the pressure inside the balloon is reduced to approximately the stable pressure 2401 or slightly above it. In some embodiments, this pressure represents the primary pressure measurement pressure. This process is also represented in the flowchart of Figure 27.

[0112] Alternatively, priming a pressure balloon may include pressurizing the balloon to above 0 mmHg, then removing a small amount of air / gas / fluid, and monitoring the pressure of the pressure balloon. The pressure of the pressure balloon will stabilize or level off as it approaches the optimal priming pressure. To determine this optimal pressure, pressure measurements are taken while removing a small amount of air from the pressure balloon, and the balloon is at the optimal priming pressure when subsequent pressure measurements are essentially identical (within a range of approximately 2 mmHg from each other). If the two subsequent measurements are not essentially identical, the pressure balloon is repressurized to above 0 mmHg, and this process is repeated. Pressure measurements taken with a small amount of air removed from the pressure balloon may be taken over approximately 5 to 15 seconds to compensate for the effect of breathing in the pressure measurement. In some embodiments, the pressure signal may require a short stabilization period after the small amount of air / gas / fluid has been removed from the pressure balloon prior to the performance of the pressure measurement.

[0113] A burst of a small amount of fluid may be approximately 0.2cc to 0.4cc. A burst of a small amount of fluid may be approximately 0.1cc to 0.5cc. A burst of a small amount of fluid may be up to approximately 0.5cc. A burst of a small amount of fluid may be up to approximately 1.0cc.

[0114] Figure 25 shows a graph illustrating a pressure balloon priming method in several embodiments. This method is similar to that shown in Figure 24, except that the pressure is increased more smoothly within the pressure-sensitive balloon without the bursts shown in Figure 24. A fluid volume is applied to the pressure-sensitive balloon, and the pressure inside the balloon is measured. The balloon pressure is increased until the measured pressure inside the balloon settles to a stable pressure 2505. This transition is shown at the inflection point 2506. The balloon pressure is increased beyond this point until the measured pressure begins to increase rapidly (for example, when the slope of the curve 2510 exceeds approximately 2 mmHg / 10 ms). This inflection point is shown at 2508. At this point, the pressure inside the balloon is reduced to a nearly stable pressure 2505 or slightly above it. In some embodiments, this pressure represents the optimal or priming pressure. This process is also illustrated in the flowchart of Figure 28.

[0115] Figure 26 shows a flowchart of balloon priming according to a specific embodiment of the present invention. Embodiments of the systems and methods of the present disclosure include automatic pressure regulation by a controller. Thus, the regulation system can detect the optimal target pressure and volume for inflating the balloon by monitoring the sensed pressure signal and increasing or decreasing the amount of air as needed. For example, during catheter insertion, a pressure regulation circuit regulating the volume and pressure of the balloon will inflate the balloon until it detects a pressure ratio of the physiological source. Upon sensing that ratio, the pressure regulation controller may increase or decrease small amounts of air or fluid (approximately 0.3 cc) in a routine sequence until the amplitude of the sensed wave is maximized. A control feedback loop between the optimized and regulated pressure (which manifests as balloon pressure and volume) and the sensed physiological pressure profile is continuous and / or iterative as needed to ensure high-fidelity measurement of physiological data. In some embodiments, automatic pressure regulation may be performed in an obvious background while physiological data is being transmitted and displayed. In other embodiments, the system may suspend the transmission of physiological data during the pressure regulation sequence.

[0116] A small amount of air or fluid may be approximately 0.2cc to 0.4cc. A small amount of air or fluid may be approximately 0.1cc to 0.5cc. A small amount of air or fluid may be up to approximately 0.5cc. A small amount of air or fluid may be up to approximately 1.0cc.

[0117] Loop controller

[0118] Certain patient parameters measured by a sensing Foley catheter system or other means are affected by and / or influenced by patient procedures performed through medical devices.

[0119] The loop controller is integrated with the controller of the sensing Foley catheter system (whether it is the same device or a separate device) and can interpret patient parameters to control the patient's medical procedures.

[0120] For example, IAP may be used to control the IV infusion rate. If the IAP is too high, the infusion rate may be reduced or stopped until the IAP returns to an acceptable range. By combining IAP with relative stroke volume and / or stroke volume variability (variations in heart rate magnitude observed in the bladder, etc., during the respiratory cycle), higher-level control of IV fluid or blood product infusion may be possible by using IAP as an indicator of excess fluid and relative increases or decreases in stroke volume variability as an indicator that additional fluid is needed. Urine volume may be further added to the control loop to provide an indicator that the fluid situation has been restored in response to urine volume. By using heart rate in combination with respiratory rate, drug infusion (drug type, infusion rate, frequency, dosage, etc.) may be controlled. In this way, drugs may be used to bring the patient to a more stable state as determined by heart rate and respiratory rate. IAP and respiratory rate may be used to control mechanical inhalers or ventilators. When IAP rises, the positive end-expiratory pressure (PEEP) delivered by the mechanical inhaler should also rise above this pressure. An indicator of insufficient inhalation may be seen in the spontaneous respiratory rate, which may be viewed as a signal based on tissue oxygenation and / or mechanical inhalation. This signal may be derived during mechanical inhalation, or preferably, the loop controller may more precisely and accurately detect the underlying respiratory rate / breathing drive by pausing the mechanical inhaler. This IAP, tissue oxygenation, and / or respiratory rate may be used to warn of anything that would worsen the patient's symptoms, and / or to provide automatic adjustment of inhaler settings, including respiratory rate, PEEP, percentage of inhaled O2, and other settings. In an ideal scenario, these parameters may be used by the loop controller to monitor and control treatment so that it is notified by machine learning and algorithmic adjustments. These are just a few examples, and many combinations exist. One or more parameters can be used to control one or more treatment devices.

[0121] Figure 29 shows one embodiment of a loop controller in a patient environment. In this example, the loop controller receives patient parameters input from a sensitive Foley catheter 2902. The sensitive Foley catheter is located in the patient's bladder 2904 and comprises a retention balloon 2908 and a pressure-sensitive balloon 2910. The sensitive Foley catheter may also include other sensors as described herein.

[0122] The sensing Foley catheter 2902 comprises a retention balloon inflation lumen, a pressure balloon sensing lumen, and a ureteral lumen. The pressure-sensitive balloon 2910 is connected to the pressure-sensitive lumen, which is connected to a pressure transducer 2920, which may be incorporated into a controller 2928. The ureteral lumen is connected to a urine volume tube 2912. The urine volume tube is emptied into a urine container 2914, which may be connected to a urine volume dispensing device 2916 or, as disclosed herein, may be incorporated into a controller. Urine volume may also be controlled by a urine pump 2918, which may be located on the drainage piping, incorporated into a controller, or located on the non-patient side of the controller, as disclosed elsewhere herein.

[0123] This patient is shown wearing a respiratory mask 2922, which is supplied by a respiratory tube 2924. The flow and composition of the respiratory gas are controlled by a respiratory device 2926.

[0124] The loop controller 2928 is connected to the urine volume measuring device 2916, the urine pump 2918, the pressure transducer 2920, and the respirator 2926, respectively, via connectors 2930, 2932, 2934, and 2936. These connectors may be wired or wireless. Alternatively, in this embodiment and other embodiments, some or all of the urine force measuring device 2916, the urine pump 2918, and / or the pressure transducer 2920 may be incorporated into the controller 2928.

[0125] In this example, the loop controller 2928 receives patient parameters input from the urine force measuring device 2916 and the pressure transducer 2920, and can use the information provided by these parameters to control the urine pump 2918 and the ventilator 2926. Some 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 sample, urine volume rate, and other parameters, including those disclosed herein.

[0126] For example, if the loop controller receives parameter information indicating an increase in the patient's IAP, the loop controller may control the respiratory perfusion rate, pressure, or other parameters. 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 increase in IAP and abnormal tissue oxygenation parameters, the loop controller may control the output of the ventilator 2926 and further control the urine pump 2918 to control the urine volume rate.

[0127] The loop controller continuously monitors the patient's parameters and adjusts the therapeutic medical device accordingly. Once the patient's parameters normalize, the control of the therapeutic medical device is adjusted accordingly so that the feedback loop controlled by the loop controller may become a closed loop. If the loop may be an open or semi-closed loop, it may be manually adjusted as needed.

[0128] Figure 30 shows another example of a loop controller in a patient environment. In this example, the patient has a venous (IV) line 3002 in a blood vessel in the arm. An IV fluid bag 3004 is raised, and IV fluid is dripped into it and / or introduced into the patient via the IV line 3002. A valve 3006 controls the flow rate of IV fluid into the patient by allowing the fluid to flow freely, restricting the flow, or stopping the flow. Here, the valve 3006 is controlled by a loop controller 2928 via a connection 3008. The IV fluid bag 3004 may contain hydration fluid and / or pharmaceuticals. One or more IV bags may be involved, and one or more valves may control the IV bags. The loop controller may control the flow and content of IV fluid into the patient based on patient parameters received by the loop controller.

[0129] Figure 31 shows another example of a loop controller in a patient environment. In this example, the patient has a fluid drainage line 3102 inserted into the abdomen. Fluid from the abdomen may flow from the patient to a receptacle 3104. The fluid flow may be controlled by a pump 3106 controlled by a loop controller 2928 via a connection 3108. The loop controller may control the flow from the patient to the receptacle 3104 via the pump 3106 based on received patient parameters. For example, if the IAP is abnormally high, the loop controller may increase the rate of fluid removal from the patient or initiate fluid removal by controlling the pump 3106.

[0130] Figure 32 shows another example of a loop controller in a patient environment. In this example, the patient has a venous (IV) line 3202 in a blood vessel in the arm. A drug infusion device 3204 controls the flow rate of drug to the patient via the IV line 3202. More than one drug infusion device may be used. Here, drug infusion device 3204 is controlled by loop controller 2928 via connection 3206. Drug infusion device 3204 may contain any suitable fluid and / or pharmaceutical. The loop controller may control the flow and contents of one or more drugs to the patient based on patient parameters received by the loop controller.

[0131] These examples illustrate some medical devices that can be controlled by a loop controller, but any medical device can be used.

[0132] Figure 33 is a detailed diagram of the loop controller. The loop controller 2928 can receive input of one or more patient parameters from a sensing Foley catheter or other device. These inputs include, but are not limited to, urine volume and percentage, pressure profile from the bladder, and sensor information from the sensing Foley catheter or other device. The pressure profile 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. This connection may be via the Internet, intranet, WAN, LAN, or other network, or it may be local via Bluetooth®, Wi-Fi, etc.

[0133] The loop controller receives one or more inputs, analyzes the data, and determines whether a medical device needs to be controlled to make a change. It may control one or more medical devices to bring the patient's parameters within a target range. Once the patient's target range is achieved, the loop controller may return the controlled medical devices to a standard state. The standard state will differ for each medical device and is likely to differ for each patient. The target range for the patient's parameters will also likely differ for each patient and for each patient's condition. For example, the target range for respiratory rate may differ depending on whether the patient is sedated or not.

[0134] Embodiments of this technology may automatically adjust the infusion rate of venous fluid or medication based on feedback from sensed cardiac output or respiratory rate. In one such embodiment, if the respiratory rate drops excessively low, the patient-controlled analgesic lamp may terminate. Since a drop in respiration can be fatal in this group, this safeguard would prevent overdose. The automated feedback system may also be advantageous in high-volume resuscitation procedures, where fluid infusion can be adjusted based on intraperitoneal pressure to prevent abdominal compartment syndrome by issuing audible warnings and reducing the infusion rate in response to rising intraperitoneal pressure. Further automated feedback features may provide direct feedback to the inhaler system to provide the optimal pressure of the ventilated gas. In settings of increased abnormal pressure, normal inhaler settings may not provide adequate breathing tailored to the patient. It may be advantageous to enable optimal patient inhalation by automatically adjusting the inhaler settings based on intraperitoneal pressure feedback from this embodiment. Embodiments of this technology may be applied as a correction in application or as an understanding of other diagnostic measurements. For example, central venous pressure may be dramatically altered in settings where intraperitoneal pressure is increased. Providing direct access to these data by a central venous pressure reporting system enables automatic correction and accurate reporting of this critical physiological parameter. Embodiments of this technology may also be used in various other ways for automated treatment, including the infusion of a fluid which may further contain activators such as vasopressors or diuretics in response to increases or decreases in cardiac output or other parameters.

[0135] In addition to directly controlling medical treatment devices, the loop controller 2928 may also provide voice alarms, including auditory alarms, email alarms, text alarms, pager alarms, etc. The loop controller 2928 may also provide outputs to other systems for system integration, such as output information to electronic medical record or other data archiving systems, or other systems. The loop controller 2928 may also receive inputs from various EHRs, EMRs, or other systems.

[0136] Medical procedures may be administered to a patient as a result of data collected and / or analyzed by a sensing Foley catheter system. These procedures may be administered automatically via a loop controller, or manually by conventional methods of administration, such as oral or injection.

[0137] Based on the results from the sensitive Foley catheter system, further medical diagnoses may also be performed.

[0138] specific gravity

[0139] Urine specific gravity may be measured using pressure and ultrasound measurements with a sensing Foley catheter. Figure 34 shows a plot illustrating how ultrasonic and pressure measurements vary depending on the density of the liquid. The liquid being measured is synthetic urine aggregate, with a specific gravity of approximately 1.100.

[0140] For a liquid with a specific gravity of 1.000, two measurement techniques are calibrated to provide the same amount of measurement. However, as density increases, these begin to fluctuate. In the case of pressure, since V=A*h and P=ρ*g*h, or V=A*ρ*g / P, an increase in density results in an increase in the reading. In the case of ultrasound, since V=A*h, v=h*2 / t, and v=(E / p)^(1 / 2), and V=A*(E / ρ)^(1 / )*t / 2, an increase in density results in a decrease in the reading. V: quantity A: Cross-sectional area h: liquid height P: pressure ρ: liquid density g: gravity v: velocity of sound t:Voice reflection speed E: Bulk modulus of a liquid

[0141] More simply, as the density of a liquid increases, the pressure increases, and its measurement is distorted more highly. At the same time, sound travels faster, distorting the ultrasound measurement less. By measuring how much these fluctuates, the density of the liquid can be determined. This assumes that the temperature is constant, but temperature can also be monitored and corrected for temperature fluctuations. Sensing Foley catheters can perform volume measurements using ultrasound and pressure, allowing for temperature measurement. In this way, by combining a sensing Foley catheter with a controller, urine specific gravity can be determined.

[0142] Decreased Condensation

[0143] Balloon catheters, especially those designed to be placed inside the human or animal body for relatively long periods, may leak over time. For example, balloons inflated with air or other gases may leak air over time. Or, balloons filled with liquids may leak liquid over time. The opposite is also true. Gas or air-filled balloons placed in fluids such as urine or blood may experience leakage of the fluid into the balloon over time. This is especially true if the balloon was inflated at a relatively low pressure.

[0144] A pressure-sensing Foley catheter is an example of a balloon designed to be inflated at relatively low pressure over a relatively long period of time. In this example, the balloon is designed to measure pressure, but it may be inflated at relatively low pressure and, as a result, may be manufactured from a relatively soft and thin material. Due to the low inflation pressure and the soft and thin balloon material, liquid may leak into the balloon over time. If the liquid inside the pressure-sensing balloon enters the catheter lumen where the pressure measurement is performed, it can negatively affect very sensitive pressure measurements.

[0145] One embodiment of this problem involves placing a very small pore filter or hydrophobic filter between the pressure-measuring balloon and the pressure-measuring lumen of the catheter. This allows for continuous priming to inflate the balloon and maintain its pressure, enabling pressure measurement through the catheter lumen. Air or gases can pass through this filter, but fluids cannot.

[0146] Other embodiments involve creating a balloon from a low-moisture-permeability material.

[0147] Other embodiments involve replacing the gas inside the balloon by instead applying vacuum and pressure to the balloon through one or more lumens.

[0148] Other embodiments involve circulating the gas within the balloon by having more than one lumen access to the balloon. Gas may be introduced into the balloon using one lumen, and gas may be drawn out of the balloon using other lumen accesses.

[0149] Other embodiments include the use of a desiccant within a balloon, a balloon lumen, a gas supply to a balloon, or any combination thereof.

[0150] Figure 35 shows the distal end of a Foley-type balloon catheter that may benefit from reduced aggregation. In this example, the balloon catheter is designed to be placed in the patient's bladder to assist in the drainage of urine from the bladder. The catheter has a retention balloon 3506 that secures the catheter in the bladder. The catheter shaft 3502 contains the lumen of the catheter. An opening 3504 allows urine in the bladder to be drained through the catheter and out of the proximal end of the catheter (not shown). An opening 3508 is for inflating and deflating the retention balloon. A pressure-sensitive balloon 3510 is inflated and deflated through an opening 3512. The pressure-sensitive balloon 3510 transmits a pressure signal from inside the bladder through the pressure lumen in the catheter shaft to a pressure transducer located near the proximal end of the catheter.

[0151] Under certain circumstances, fluid may leak into the pressure balloon 3510 over time. Fluid may also enter the catheter shaft 3502 from within the pressure balloon 3510 through the opening 3512. Fluid in the pressure lumen can adversely affect pressure readings from the pressure balloon. Therefore, it is desirable to prevent fluid from entering the pressure balloon through the opening 3512, or, if possible, to reduce the amount of fluid entering the pressure balloon.

[0152] Figure 36 shows one embodiment of a filter inside a balloon. Filter 3602 is provided between the inside of balloon 3510 and the pressure lumen inside the catheter at the opening 3512. Preferably, filter 3602 is made of a material that allows gas to pass through but not fluid. For example, the filter may be made of a hydrophobic membrane such as Versapor, PTFE, or ePTFE. This filter may also be made of a polymer such as nylon or any 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 thickness of this filter may be in the range of about 6 mm to about 12 mm, or the thickness of this filter may be about 1 mm to about 6 mm. The pore size is related to balloon sensitivity. 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, with a pressure difference sensing ability in the resolution range of 0.01 mmHg. If the sensitivity of the pressure measured through the pressure balloon can be lower, a filter with smaller pores may be used. If the pressure measured through the pressure balloon must be more sensitive, a filter with larger pores may be used.

[0153] Figure 36 shows a filter in the form of tubing that surrounds the catheter shaft at the opening 3512 and completely covers the opening. This filter may be bonded to the catheter shaft at its ends using any suitable adhesive or other means such as heat shrinkage. The seal between the filter and the catheter is ideally gas-impermeable so that gas entering and leaving the balloon 3510 through the opening 3512 passes through the filter 3602.

[0154] Figure 37 shows another embodiment of the present invention, which features a smaller catheter shaft in which the filter is installed inside the balloon. The catheter shaft 3704 inside the balloon has a smaller diameter than the catheter shaft 3706 not located below the balloon. This prevents the majority of the added filter 3702 from increasing the diameter of the deflated balloon.

[0155] Figure 38 shows an embodiment of Figure 37 with the balloon deflated, demonstrating that the reduction in the diameter of the catheter shaft below the balloon region prevents excessive inflation of the balloon catheter.

[0156] Figure 39 shows another embodiment of the filter below the balloon. In this embodiment, the filter 3902 does not extend over the entire shaft of the catheter, but instead is a flat or curved piece of filter bonded to the catheter shaft via an adhesive or other suitable means. The adhesive preferably seals the filter over its entire edge without penetrating the inflation / deflation / pressure measuring opening 3512 of the balloon.

[0157] Figure 40 shows another embodiment of filter 4002 with a shorter filter length.

[0158] Figure 41 shows another embodiment of a balloon catheter with a filter. In this embodiment, the balloon catheter has two lumens that are in fluid communication with the balloon. Filter 4102 covers opening 4104, while opening 4106 is not covered. In this embodiment, openings 4104 and 4106 may each access separate lumens of the catheter or the same lumen. In embodiments where they access separate lumens, balloon inflation, deflation, and pressure measurement may be performed through either lumen. For example, pressure measurement may be performed through the lumen in fluid communication with opening 4106 until fluid generation in the lumen adversely affects the pressure measurement. At this point, the pressure transducer may be switched to the lumen in fluid communication with opening 4104 so that pressure measurement may be performed through a lumen without fluid.

[0159] Alternatively, pressure measurement may be performed through the lumen fluid-connected to opening 4106 until the generation of liquid in the lumen adversely affects the pressure measurement. At this point, gas may be introduced into the lumen fluid-connected to opening 4106 to remove the fluid from the lumen. Simultaneously, this gas may be drawn out from the balloon through the lumen connected to opening 4104. In this way, the liquid can be removed from the lumen connected to opening 4106, and pressure measurement may be resumed through that lumen. This line cleaning procedure can be programmed to occur periodically.

[0160] Figure 41 shows two balloon openings 4102 and 4106 on different sides of the catheter, with filter 4104 covering only one of the openings. Alternatively, Figure 42 shows an embodiment similar to Figure 41, where the two openings 4204 and 4206 are adjacent to each other, except that filter 4202 covers only one of the openings.

[0161] Figure 43 shows one embodiment of the present invention in which filter 4302 covers a larger opening 4304. A larger opening may be desirable to obtain more accurate pressure measurements from the balloon. Also, due to the excessive integration that the filter and, if applicable, its adhesive means provide to the catheter region around the opening 4304, the addition of filter 4304 may allow for a larger opening.

[0162] Figure 44 shows one embodiment of the present invention in which the filter 4402 is attached to the catheter shaft via a heat-shrinkable tubing segment 4404. This allows for an airtight seal between the filter and the catheter while ensuring that the catheter opening 4406 remains clean.

[0163] Figure 45 shows an embodiment similar to Figure 44, where the catheter shaft is reduced within the balloon region. This allows the balloon to deflate without causing inflation in the catheter to which the filter is attached. The filter 4502 is attached to the catheter shaft via a heat-shrinkable tubing segment 4504. This enables an airtight seal between the filter and the catheter while ensuring that the catheter opening remains clean.

[0164] Figure 46 shows one embodiment of the present invention in which the filter 4602 is installed inside the catheter at the opening.

[0165] Figure 47 shows one embodiment of the present invention in which the balloon has two access lumens 4702 and 4704. In this embodiment, the balloon catheter has two lumens that are in fluid communication with the balloon. In this embodiment, the openings 4702 and 4704 may each access separate lumens of the catheter or the same lumen. In embodiments in which they access separate lumens, the balloon's inflation, deflation, and pressure measurement may be performed through either lumen. For example, pressure measurement may be performed through the lumen that is in fluid communication with opening 4702 until the generation of liquid in the lumen adversely affects the pressure measurement, or until a set period of time. At this point, gas may be introduced into the lumen that is in fluid communication with opening 4702 to remove liquid from the lumen. Simultaneously, gas may be drawn out of the balloon through the lumen that is in fluid communication with opening 4704. The reverse is also possible; that is, fluid may be introduced into the lumen that is in fluid communication with opening 4704 and removed from the lumen that is in fluid communication with opening 4702. In this way, the liquid can be removed from the lumen that is in fluid communication with opening 4702, and pressure measurement may be resumed through that lumen. This line cleaning procedure can be programmed to occur periodically. Although openings 4702 and 4704 are shown here opposite each other, these openings may be staggered.

[0166] Figures 48 and 49 show two different pressure balloon designs, but any suitable design and / or shape may be used. The balloons may be manufactured in different ways depending on the balloon material. Some materials are better suited to blow molding, while others are better suited to dipping. Other manufacturing techniques may be used, for example, resistance heat sealing. Figure 48 shows an example of a blow-molded balloon. Figure 49 shows an example of a dipping-molded balloon.

[0167] Some examples of materials from which balloons may be manufactured include urethane, polyurethane, polyethylene, nylon, polyvinylidene fluoride, or any other suitable polymer, or other materials, or any combination thereof.

[0168] Balloon coatings may also be used to reduce the fluid permeability of the balloon. Examples of such coatings include poly(p-xylene) polymer or parylene.

[0169] In some embodiments, it is desirable to prevent any moisture evaporation from entering the pressure balloon. In these embodiments, the balloon may be made of a material that is impermeable to water or fluids. Several materials described herein are preferred. Biaxially oriented polyethylene terephthalate (BoPET), often referred to by its brand name Mylar, may also be used. Metallized polymers or any other material may also be used.

[0170] In some embodiments, a 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 then address or resolve such droplets. Particularly in hypothermic settings, moisture in the air lumen may condense and form obstructive water droplets. Water droplets (or bubbles in a water-filled lumen) in an air-filled lumen can interfere with or complicate the pressure signal due to the surface tension of the water. Therefore, in some embodiments of the technology of this disclosure, the pressure-transmitting lumen may include hydrophilic features (such as a coating on the wall of the lumen itself or hydrophilic fibers along the length of the lumen) to allow moisture to escape from the lumen in order to maintain a continuous and uninterrupted airflow path. In some embodiments, a hygroscopic composition (e.g., silica gel) may be used along the air injection line or within the air injection lumen to capture water or moisture. In some embodiments, the hygroscopic composition may be contained within the catheter so that the air injection circuit does not require replacement service of this material.

[0171] In some embodiments, moisture accumulation may be prevented by using dry air or gas in the pressure tube lumen and / or pressure balloon.

[0172] In some embodiments, a hydrophobic or hydrophilic coating may be used in the pressure tube lumen and / or pressure balloon.

[0173] gas content

[0174] Another embodiment involves measuring the relative content of oxygen or other gases in urine or tissue by using a hydrophobic filter or membrane as an interface with urine in the mucosal lining of the bladder or urethra.

[0175] In some embodiments of the sensing Foley catheter, it is desirable to measure changes over time in the gas content of gas-containing tissue and / or urine. 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 impermeable to liquids, and may be a hydrophobic membrane or other suitable membrane, for example. The pore size of the hydrophobic membrane may be about 5 microns. Alternatively, the pore size of the hydrophobic membrane may be about 3 to about 7 microns.

[0176] Figure 50 shows a sensitive Foley catheter equipped with an oxygen-permeable membrane. The retention balloon 5002 is in fluid communication with the inflation / deflation port 5010. Urine flows through the opening 5004, through the catheter, and out through port 5012, which is in fluid communication with the opening 5004. The pressure-sensitive balloon 5006 is in fluid communication with the lumen 5014. The gas-permeable membrane 5008 covers the opening at the distal end of the catheter, which is in fluid communication with the lumen 5016.

[0177] Figure 51 shows a sensing Foley catheter with oxygen permeability similar to that shown in Figure 50, except that the membrane 5108 is located between the pressure-sensitive balloon 5106 and the retention balloon 5102. The opening 5104 for urine may be located at any location distal to the retention balloon 5102.

[0178] Figure 52 shows one embodiment of a sensing Foley catheter in which a membrane 5204 is incorporated within a gas-sensing balloon 5202. In this figure, the gas-sensing balloon 5202 is distal to the pressure-sensitive balloon 5206, but other embodiments are shown in Figure 53 and are not applicable here. The gas-sensing balloon 5202 may be made of silicone, polymer, or any other suitable material.

[0179] The membrane material may be the same as the hydrophobic membrane material described in other embodiments of this specification. This membrane is permeable to gases, or permeable to certain gases, but impermeable to liquids such as urine. In this way, gases can pass through the membrane and enter the catheter, allowing for the measurement of gas content in tissues and / or urine, and / or changes in gas content over time. The gases to be measured may include oxygen, nitrogen, carbon dioxide, or other gases.

[0180] The catheter may be positioned in the patient such that the membrane is located either inside the bladder or the urethra. Here, the membrane is shown on a pressure-sensitive Foley catheter with a pressure-sensitive balloon, but the gas-permeable membrane may be positioned on any implanted catheter, including catheters placed in blood vessels or other body cavities. The membrane may be in direct or joint contact with fluids, gases, or body tissues.

[0181] Figure 54 shows a controller that controls the measurement of oxygen or other gases. The controller is typically located outside the patient and will connect to the catheter via a port, for example, port 5016. The controller may also control the pressure-sensitive function or other functions of the sensing Foley catheter, or it may be a separate controller.

[0182] Here, the gas measurement controller 5402 is shown along with representations of the catheter 5404 and the gas transport membrane 5406. The gas measurement controller 5402 comprises an air or gas inlet 5408, an air or gas exhaust port 5410, a pump 5412, an oxygen or other type sensor 5414, and a check valve 5416.

[0183] In this embodiment, the pump 5412 periodically pushes a small amount of air or other gas into the catheter through piping. The air passes through a membrane "window" 5406, and the oxygen content of the air changes 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 (behind the gas measurement controller box 5402), the oxygen percentage of the air is measured using an optical fiber or other type of oxygen sensor. The pump may operate for only a short period to equilibrate the air with the tissue / fluid for the duration of the system.

[0184] The check valve 5416 helps to limit the mixing of air passing through the system with outside air or the air used during the previous measurement.

[0185] The measured oxygen or other gas content may be very small. The measurement may indicate either an absolute or relative gas level. For example, a gas measurement controller may show the patient's relative oxygen content over time to indicate changes in the patient's symptoms.

[0186] Figure 55 is a schematic diagram showing how a gas measurement controller interacts with a catheter to measure the gas content of a patient's urine or tissue. The catheter 5502 comprises a urine discharge lumen 5504 and gas measurement lumens 5506 and 5508, which are in fluid communication with a gas transport membrane 5510. Lumen 5506 contains air or other gas entering the catheter, and lumen 5508 contains air or other gas exiting the catheter after the transport gas has passed through the gas transport membrane. The level of oxygen or other gas in the outflowing gas is measured to determine the oxygen level or change in oxygen levels in the patient's urine and / or tissue. The incoming gas measurement lumen 5506 may be open to ambient air or other sources, or it may be a closed system in which the gas in lumens 5506 and 5508 circulates continuously so that changes in gas content can be easily determined over time. In other words, the air or gas inlet 5408 and the air or gas exhaust port 5410 in Figure 54 may be in fluid communication with each other.

[0187] When the incoming gas measuring tube lumen 5506 is open to the surroundings, the pump may be operated intermittently so that it takes longer for the gas in the gas measuring tube lumen to move parallel to the surface of the membrane. This results in a more intermittent measurement of the gas concentration being measured, and consequently, a higher sensitivity to the measurement.

[0188] This pump may operate continuously or intermittently, regardless of whether the system is open or closed, but as a result, the sensitivity of the measurement is higher when operated intermittently in open system mode. In closed system mode, the trend may become more apparent as the gas measured in the system equilibrium with the gas levels of urine, urine, fluid, or tissue being measured.

[0189] In this embodiment, the ureteral lumen and the gas measurement lumen are separate components. However, the gas transport membrane may also be provided between the ureteral lumen and the gas measurement lumen, as shown in Figure 56, in which case the gas transport membrane 5602 is in fluid communication with the ureteral lumen.

[0190] Figures 57A and 57B show embodiments of additional components for gas measurement. 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 comprises a hydrophobic filter 5704, which may be made of a material disclosed elsewhere herein. The gas inlet lumen 5706 and the gas outlet lumen 5708 allow the gas to pass through the filter 5704, which is in gas communication with the urine in the drainage system. The air or gas near the filter 5704 is equilibrated very quickly with the gas in the urine in the drainage system. Figure 57B shows the flow path of the airflow across the filter 5704. The gas outlet lumen 5708 is in fluid communication with a controller (not shown herein) that analyzes the gas in the lumen for one or more related gases. The gas inlet lumen 5706 may be open to the surrounding or other gases, or it may be in a closed loop with the gas outlet lumen 5708 in the controller. The controller may be the same as the controller for measuring urine volume as described elsewhere in this specification, or it may be a separate controller. Lumens 5706 and 5708 may be incorporated into the drainage tube 1001, or they may be separate. The gas measuring component 5702 may be a separate component, as shown herein, or it may be incorporated into the vent cover 1016. Alternatively, the gas measuring component 5702 may be located anywhere in the system.

[0191] Detection / determination of specific conditions

[0192] Figure 58A shows a table listing parameter combinations that provide fingerprints, or characteristic properties (combinations of parameters), for different indicators of AKI (prerenal, nephrogenic, and obstructive). There may also be fingerprints, or characteristic properties, for the timing of parameter changes, which can also be used to determine the cause of AKI (for example, certain parameters change more rapidly in nephrogenic AKI caused by glomerulonephritis than in nephrogenic AKI caused by acute renal tubular necrosis). This multi-parameter approach also suggests that different causes of AKI have different effective treatments (for example, recombinant alkaline phosphatase is effective in treating nephrogenic (infectious) AKI but not in treating non-infectious AKI).

[0193] Figure 58B shows a table listing parameter combinations that give fingerprints, or characteristic properties (combinations of parameters), to different indicators of sepsis, AKI, and acute respiratory distress syndrome (ARDS). These characteristic properties include increases, decreases, or both of various patient parameters, including urine volume, heart rate, respiratory rate, temperature, stroke volume, cardiac output, and abdominal perfusion pressure. Abdominal perfusion pressure is calculated by subtracting intra-abdominal pressure (IAP) from mean arterial pressure (MAP). Mean arterial pressure is equal to cardiac diastolic pressure (DP) plus 1 / 3 of pulse pressure (PP) (pulse pressure is equal to systolic pressure minus cardiac diastolic pressure). In short, MAP = DP + 1 / 3PP.

[0194] Other patient parameters may also be used. One, some, or all relevant parameters may be used as controls to communicate the diagnosis and / or risk to the user or other devices. Patient parameters obtained by a sensing Foley catheter system may be used alone or in conjunction with parameters obtained elsewhere, such as information from EKG, blood pressure monitors, or EMR.

[0195] Sensing Foley catheter systems provide real-time, automated, and precise monitoring of physiological parameters for the early detection of various medical conditions. Real-time multivariate (point) and time-series (trend) analysis of these high-frequency data streams may be developed to inform our machine learning-driven models of highly sensitive physiological features for early sepsis (or other medical condition determination). This would improve clinical outcomes by enabling early diagnosis and intervention. Relevant characteristic properties of data associated with physiological changes occurring before and / or during the onset of a particular medical condition can be continuously enhanced using machine learning via artificial neural networks, strengthening relevant parameters, weakening less relevant parameters, and building or breaking connections. This would allow controllers to utilize algorithms to distinguish medical conditions from each other or from normal pathology or other pathologies.

[0196] In some embodiments of the present invention, urine volume may be measured immediately after the patient is administered a diuretic. This type of test can be a strong indicator of whether a patient with AKI will progress to a more severe stage and / or die. If the patient's urine volume increases after administration of a diuretic, this indicates that the patient is less likely to progress to a more severe stage of AKI. If the patient's urine volume does not increase significantly after administration of a diuretic, this indicates that the patient is more likely to progress to a more severe stage of AKI. The present invention allows for rapid and accurate measurement of urine volume in real time. Therefore, the response to a diuretic can be detected more quickly (in minutes rather than hours) than with conventional urine measurement techniques.

[0197] This test can be automated with a controller that provides a controlled dose of a diuretic, after which urine output is monitored over several minutes or hours, preferably only over several minutes. The diuretic administered may be furosemide or any other suitable loop diuretic or other diuretic. The diuretic may be administered and the data may be collected 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 standardisation of a furosemide stress test to predict the severity of acute kidney injury. Crit Care. 2013 Sep 20;17(5):R207, which is incorporated herein by reference.

[0198] In addition to detecting AKI, the present invention enables detection of urinary tract infection (UTI), as indicated by decreased oxygen pressure, altered 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 in some cases also in the presence of AKI, by combining urinary markers for the unique fingerprint of UTI. The unique UTI fingerprint can alert a clinician to the presence of a UTI.

[0199] In addition to detecting AKI and UTI using the aforementioned parameters, these parameters may also be used in combination with intra-abdominal pressure (IAP), respiratory rate (RR), heart rate (HR), cardiac output (CO), relative stroke volume (RSV), temperature (Temp), pulse pressure (PP), urine conductance (UC), urine output (UO), and / or stroke volume (SV) readings, which are already used to detect conditions such as intra-abdominal hypertension (IAH), abdominal compartment syndrome (ACS), and sepsis. Adding measurements of IAP, RR, HR, CO, RSV, Temp, PP, UC, UO, and / or SV to the algorithms described herein may increase the sensitivity and specificity of detection of AKI or UTI. Other clinical applications include the treatment of trauma and burns. Conversely, adding the measurements obtained in the present invention to measurement algorithms for IAP, RR, HR, CO, RSV, Temp, PP, UC, UO, and / or SV may increase the sensitivity and specificity of detection of IAH, ACS, or sepsis.

[0200] In addition to absolute measurements of IAP, RR, HR, CO, RSV, Temp, PP, UC, UO, gas concentration and / or SV, trend data of these parameters may be used to detect IAH, ACS, sepsis, or other conditions. For example, slopes over time of values of these parameters and / or variations over time in values of these parameters may also be used. Other examples of using data trends include pulse pressure waveform analysis and the use of pulse waveform velocity (or pulse transit time). Pulse transit time can be determined by acquiring cardiac signals such as EKG from a sensorized Foley catheter and / or other locations, and / or determining the time it takes for a pulse wave pressure signal to travel to the bladder. Multiple parameters and / or parameter trends may be used to determine the presence of IAH, ACS, sepsis, or other conditions.

[0201] Some examples of using trend data include the following.

[0202] A decrease in urine output (UO) with stable vital signs (other) may indicate acute kidney injury. A decrease in stroke volume may indicate renal ischemia. A sudden increase in urine output with stable vital signs may indicate toxic acute kidney injury.

[0203] • An increase in respiratory rate in response to a decrease in stroke volume may indicate pulmonary embolism, bleeding, or other loss of volume.

[0204] An increase in respiratory rate when vital signs are stable may indicate an impending airway obstruction.

[0205] • A decrease in respiratory rate during the stability setting of other parameters may indicate an overdose of anesthetic. This is a significant problem for patients with controlled analgesia.

[0206] An increase in intraperitoneal pressure (IAP) and an increase in urine output during the establishment of a stable stroke volume may be indicators of imminent fluid overload.

[0207] A decrease in UO and an increase in IAP accompanied by a decrease in cardiac output may be an indicator of insufficient concern. This may be due to fluid overload, sepsis, etc.

[0208] The present invention is usable in various hospital settings (e.g., emergency rooms, operating rooms, intensive care units, wards). The device may be used at any time to monitor the progression of AKI and whether it is progressing or regressing. Its algorithm acts to alert clinicians to new progressions of AKI or changes in AKI symptoms. The device may be deployed to detect the onset of AKI before kidney damage occurs (e.g., for patients undergoing cardiac surgery, to detect whether kidney damage began during surgery). It may also be deployed to detect the extent of kidney damage when it is already present. The device may be used to monitor responses to treatment / therapeutic interventions (e.g., renal replacement therapy, fluid resuscitation).

[0209] Alternative Embodiments

[0210] Embodiments of this technology may also report patient movement in the detection or diagnosis of paroxysmal disorders. In these embodiments, pressure fluctuations may trigger an EEG or recording device to initiate a period of intensive monitoring during an event suspected to be a seizure. Additionally or alternatively, pressure sensors, acoustic sensors, or other sensors may be used to detect hyperactivity, including peristalsis, patient movement, seizure activity, patient tremors, coughing frequency, coughing severity, sleep duration, sleep quality, speech detection, and patient extensibility (movement or lack thereof), which may alert healthcare providers if the patient is not moving and needs to be turned or rolled. This movement-related information may also be relayed to a hypothermia device, drug delivery device, or other device to control or mitigate seizure activity, tremors, and / or coughing.

[0211] In some embodiments, a 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 then address or resolve these droplets. Particularly in hypothermic settings, moisture in an 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 interfere with or complicate the pressure signal due to the surface tension of water. Therefore, in some embodiments of the technology of this disclosure, the pressure-transmitting lumen may include hydrophilic features (such as a coating on the wall of the lumen itself or hydrophilic fibers along the length of the lumen) to allow moisture to escape from the lumen in order to maintain a continuous and uninterrupted airflow path. In some embodiments, a hygroscopic composition (e.g., silica gel) may be used along the air injection line or within the air injection lumen to capture water or moisture. In some embodiments, the hygroscopic composition may be contained within the catheter so that the air injection circuit does not require replacement service of this material.

[0212] In some embodiments of the technology of this disclosure, as further detailed above, air may be intermittently (and automatically) injected into and extracted from the pressure-sensitive balloon so that the balloon is kept in a constant state of optimal priming. In the case of wicking fibers or hydrophilic coatings in the lumen, air extraction may also contribute to the removal and capture of water from the air line. In the example of a liquid-filled lumen, hydrophilic fibers or hydrophilic coatings inside the pressure lumen would offer similar advantages in allowing the lumen to deal with air bubbles. In this example, although air bubbles may deform the signal, the surface tension at the air-water interface is mitigated by the hydrophilic coating in the catheter lumen.

[0213] Furthermore, in the case of lumens filled with liquid and / or air, controlled extrusion and lumen shape may be used to prevent obstruction. For example, in some embodiments of the art, a Foley-type catheter may have a star-shaped lumen with a cross-sectional profile. Such lumens are typically protected from obstruction by water droplets because droplets tend to aggregate on themselves and push against the hydrophobic wall. This behavior tends not to allow filling of the cross-sectional space, leaving the air channel open around the water droplets and communicating with the sensor. The same logic applies to bubbles in water in a hydrophilic star-shaped water lumen. In this case, hydrophilic droplets would adhere to the wall, allowing for a continuous water column that excludes bubbles to the center of the lumen. The same applies to hydrophobic liquids in a hydrophobic lumen. In some embodiments, the catheter may comprise an air channel and a sensor incorporated within the fluid lumen that can send pressure back to the catheter itself or the sensor.

[0214] The drainage tube is a multi-lumen tube comprising a urinary line, a pressure lumen, and a thermocouple wire, connected to a mounting point at one end and to a controller at the other end.

[0215] The Foley catheter may be extruded with BaSO4, or an X-ray radiopaque marker may be attached to enable fluorescence observation.

[0216] The thermistor positioned at the tip of the catheter may be fixed in place using a combination of extrusion profiles and assembly techniques.

[0217] In some embodiments, the sensing Foley catheter may be equipped with a blood pressure sensing element, which may take one of several forms. In one embodiment, the blood pressure sensing element is equipped with an optically analyzable pressure delivery balloon (a separate dedicated balloon, a device retention balloon, or a balloon fluid-communicated with a pressure-sensitive balloon) which is inflated to determine the pressure at which the tube in the bladder or urethra becomes equilibrium and blood flow stops. This approach provides a reading of the perfusion pressure of the tissue in contact with the pressure delivery balloon, such as a reading that can reflect 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, which can be particularly effective in the early detection of these conditions. In predicting sepsis, embodiments of the present invention may be able to improve the prediction of sepsis by receiving white blood cell count information.

[0218] Other methods may be used to detect tissue whitening or ischemia, but a common methodological embodiment provides compression of the vascular system by intermittent expansion within lumens, body cavities, or body tissues. Embodiments of the apparatus and related methods may also be used to detect perfusion pressure in other areas of the body by optical detection of intermittently expandable members and the presence of blood flow or blood.

[0219] Information on intratissue perfusion may be provided by sensors positioned on the catheter shaft such that the sensors are in contact with the urethral wall when the catheter is in place. These sensing techniques may include microdialysis, pyruvate, lactate, pO2, pCO2, pH, perfusion indices, near-infrared spectroscopy, laser Doppler flowmeter, urethral capnography, and orthogonal polarization spectroscopy. Any of these tests may be performed on the urine or the bladder wall itself to result in a measurement of intratissue perfusion.

[0220] Another embodiment of the sensing Foley catheter system includes an embodiment of a cleaning mechanism comprising a device and / or a port for generating a positive airflow near the start of a drainage line. The positive airflow promotes drainage by causing urine to flow through the drainage line. The positive airflow device may comprise a one-way valve provided 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.

[0221] In some embodiments, the urine cleaning mechanism comprises a coating provided on the inner side of the urination tube to reduce surface tension and promote drainage. In one aspect, the coating is a hydrophobic polymer including but not limited to PTFE or FEP.

[0222] In still other embodiments, the cleaning mechanism comprises a cylindrical hydrophobic vent filter insertable into the drainage lumen of the device such that air can be evacuated along the entire length of the device. Partially hydrophobic vents are incorporated at set intervals, which ensures that air can be evacuated from the tube when passing through these regions. In this embodiment, the hydrophobic vents will be spaced apart from each other by a minimum distance of 1 to 2 feet to prevent the vents from being submerged in urine. By providing redundancy, the plurality of vents / filters prevent failure of any one filter / vent caused by submersion. In an ideal configuration, the vent is made of PTFE or ePTFE material, and will be fixed at anchor portions or grommet-mounted in the tube at intervals that facilitate easy manufacturability. In alternative embodiments, the vent takes the form of a slit or a spiral extending along the length of the drainage tube, allowing air to escape from the tube at any point. This prevents airlocks and / or prevents the drainage tube from being position-dependent when removing airlocks.

[0223] In an alternative embodiment, an airlock is prevented by an expandable drainage tube, which prevents an air pocket from forming in the higher part of the tube and prevents urine from accumulating in the lower part. The expandable tube prevents this by keeping the tube as straight as possible between the urinary catheter and the collection bag. In one embodiment, the expandable drainage tube consists of multiple telescopic sections that can be stretched or shortened to match the distance from the patient to the collection bag. In another embodiment, the drainage tube is provided with pleats to form an accordion, which are expandable, collapsible, or deformable as needed. In yet another embodiment, the tube is coiled. In yet another embodiment, the drainage tube is retractable by a spring coil that winds the tubing around a wheel to achieve the appropriate length.

[0224] Relative cardiac output and relative tidal volume may also be calculated based on the deflection of pressure sensors and / or other force gauges. When sampled at a sufficient frequency (e.g., 1 Hz or higher), respiratory deviation can be quantified relative to the amplitude of the deviation at the time of catheter placement. Generally, larger deviations are associated with deeper breathing or, in settings of upward drift at baseline, with higher peritoneal pressure. Small peaks in the oscillatory respiratory wave produced by cardiac pumping may be tracked using a higher sampling rate (e.g., 5 Hz or higher), and the amplitude of this wave may be used in settings of relatively constant peritoneal pressure to determine relative cardiac output and, in settings of known stable peritoneal pressure, absolute stroke volume and / or cardiac output.

[0225] Using intra-abdominal or bladder pressure sensed by one embodiment of the technology of this disclosure, the level of patient movement (which may fluctuate between substantially no movement and a high level of movement, for example) may be determined and reported to the healthcare provider. Short bursts of peaks and valleys in bladder pressure activity may serve as an approximation of body movement, such that the bladder pressure profile is a strong indicator that the patient is using abdominal muscles to, for example, get up or get out of bed. This embodiment may be particularly beneficial for patients at risk of falling. In patients at risk of falling, the healthcare provider may be notified that the patient is getting up and respond accordingly. Alternatively, the device may be used to report that the patient is inactive and / or not moving enough.

[0226] The pulse oximetry element allows for the determination of blood oxygen concentration or saturation and may be positioned at any point along the length of the urethra in the catheter. In some embodiments, one or more sensors may be positioned within the tubing of the device to ensure a proper approximation of the urethral mucosa. This technology allows healthcare providers to reduce pressure in the bladder with a urinary catheter and obtain repeatable and accurate pulse oximetry data. The power source for pulse oximetry may be integrated into the urine collection receptacle or the catheter itself. In some embodiments, the pulse oxygen meter is reusable and the catheter interface is disposable. In this arrangement, the pulse oxygen meter is reversibly attached to the disposable catheter and removed when oxygen measurement is no longer desired. Embodiments of the sensing Foley catheter may include optically transparent or sufficiently transparent channels for the oxygen measurement signal, such as fiber optic cables, transparent windows, and interfaces with reusable oxygen metering devices. The methods and apparatus for urethral pulse oximetry may be used in conjunction with any of the other embodiments detailed herein, or they may be standalone devices.

[0227] Infection may be prevented by using materials with antimicrobial coatings or embedded antimicrobial compounds on a sensitive Foley catheter. Examples of antimicrobial coatings / materials include silver, silver citrate, parylene, or any other suitable material.

[0228] In assisting the assessment of the presence or risk of cardiac dysfunction, pulmonary blood flow variability may also be determined using a sensitive Foley catheter. Decreased left ventricular function can lead to an increase in pulmonary blood flow (PBV) or a decrease in pulmonary blood flow 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 transition time (PTT). Cardiac output can be determined as the product of stroke volume and heartbeat, where stroke volume is the area under the fluid-time curve during one cardiac cycle. Pulse transition time may be obtained by observing the delay between the QRS complex in the EKG and the appearance of the signal in the bladder. The EKG signal may be obtained from a separate EKG lead, a lead integrated into a sensitive Foley catheter, a lead integrated into a catheter insertion kit, or from other locations. EKG may also be read from urine, or from any location within the system. Two leads may be used to more accurately determine pulse transition time.

[0229] It was found that stroke volume, ejection fraction, and PBV variability decrease after myocardial infarction, with the greatest change observed in PBV variability. Therefore, determining PBV variability and identifying a decrease in PBV variability may strongly indicate cardiac dysfunction or the risk of cardiac dysfunction.

[0230] Data collected by a sensing Foley catheter system may be stored in a database and analyzed for trend analysis or other purposes. For example, data collected from several patients may be aggregated and used anonymously to better handle, monitor, or predict future patient behavior. For example, data collected over time in relation to heart rate, respiratory rate, temperature, infection, etc., may be aggregated and analyzed by a controller to identify trends such as relationships between various parameters and outcomes. For example, a specific trend in temperature alone or in combination with other parameters may be a predictor of infection, sepsis, ARDS, and / or AKI. Figure 58 shows some known examples, but other currently unknown oral samples may also emerge from the aggregated patient data.

[0231] Data collected by a sensing Foley catheter system may be integrated with an electronic health record (EHR) or electronic medical record (EMR) and / or other system. Data collected by the controller of the sensing Foley catheter system may interface directly or indirectly with the EMR / EHR system. Data from the EMR / EHR, such as patient demographic or medical history data, may also be integrated with the sensing Foley catheter system.

[0232] Examples of data processing systems

[0233] Figure 60 is a block diagram of a data processing system, which may be used in conjunction with any embodiment of the present invention. For example, system 6000 is It may be used as part of a controller as shown in some embodiments of this specification. While Figure 60 shows various components of a computer system, it is not intended to represent any particular architecture or method of incorporating these components, and such details are not closely related to the present invention. It will also be understood that network computers, portable computers, mobile devices, tablets, mobile phones, and other data processing systems having fewer or perhaps more components may be used in conjunction with the present invention.

[0234] As shown in Figure 60, the computer system 6000 is in the form of a data processing system and comprises one or more microprocessors 6003 and a bus or interconnect 6002 connected to ROM 6007, volatile RAM 6005, and non-volatile memory 6006. The microprocessor 6003 is connected to cache memory 6004. The bus 6002 interconnects these components together, or interconnects these components 6003, 6007, 6005, and 6006 to a display controller and display device 6008 and an input / output (I / O) device 6010 which may be a mouse, keyboard, modem, network interface, printer, and other device known in the art.

[0235] Typically, the input / output device 6010 is connected to the system via the input / output controller 6009. Volatile RAM 6005 is typically implemented as dynamic RAM (DRAM) that requires continuous power to refresh or maintain data in memory. Non-volatile memory 6006 is typically magnetic hardware, magneto-optical drives, optical drives, or DVD RAM or other types of memory systems that retain data even after power is removed from the system. It is usually non-volatile memory, random-access memory, but is not necessarily required.

[0236] Figure 60 shows that the non-volatile memory is a local device directly connected to the rest of the data processing system, but the present invention may also utilize non-volatile memory located remotely from the system, such as a network storage device connected to the data processing system via a network interface such as a modem or an Ethernet® interface. Bus 6002 may include one or more buses connected to each other through various bridges, controllers, and / or adapters, as is well known in the art. In one embodiment, the I / O controller 6009 includes a USB (Universal Serial Bus) for controlling USB peripherals. Alternatively, the I / O controller 6009 may include an IEEE-1394 adapter, also known as a FireWire adapter, for controlling FireWire® devices.

[0237] Prior to the detailed description, several parts have been presented in terms of algorithms and symbolic representations of operations on data bits in computer memory. These algorithmic descriptions and representations are the methods used by those skilled in the art to most effectively communicate the subject matter of their work to others in the art. Here, an algorithm is also typically considered as a consistent sequence of actions that produce a desired result. This action requires the physical manipulation of physical quantities.

[0238] However, all of these and similar points must be associated with appropriate physical quantities, and it must be kept in mind that they are merely convenient labels assigned to these quantities. As is clear from the above considerations, unless otherwise noted, throughout this description, any consideration using the terms set forth in the following claims will be understood to mean the operation and processes of a computer system or similar electronic processing unit that manipulates and converts data represented as physical (electronic) quantities in the registers and memory of a computer system to other data similarly represented as physical quantities in computer system memory or registers, or other systems that store, transmit, or display such information.

[0239] The technology shown in the drawings can be implemented using code and data stored and executed on one or more electronic devices. Such electronic devices store and communicate (internally and / or with other electronic devices via a network) the code and data using computer-readable media such as persistent computer-readable storage media (e.g., magnetic disks, optical disks, random-access memory, read-only memory, flash memory devices, phase-shift memory) and non-persistent computer-readable transmission media (e.g., electrical, optical, acoustic, or other forms of propagating signals such as transport waves, infrared signals, digital signals).

[0240] The processor or method depicted in the preceding drawings may be implemented by processing logic including hardware (e.g., circuits, dedicated logic, etc.), firmware, software (e.g., implemented on a persistent computer-readable medium), or a combination of both. Although the process or method has been described above in terms of several sequence operations, it should be understood that some of the operations described may be performed in a different order. Furthermore, some operations may not be performed sequentially but in parallel.

[0241] Unless otherwise specified, all technical terms used herein have the same meaning as commonly understood by those skilled in the medical field. While specific methods, apparatuses, and materials have been described herein, any methods and materials similar to or equivalent to those described herein may be used in the practice of the present invention. Embodiments of the present invention have been described in some detail and as examples, but such examples are for illustrative purposes only and are not intended to limit the scope. Various terms have been used in this description to facilitate understanding of the present invention. The meaning of these various terms will be understood to extend to their general linguistic or grammatical usage. Furthermore, some logical reasoning has been mentioned above to further facilitate understanding of the technology, but the appended claims of the present invention are not bound by such reasoning. Furthermore, without departing from the scope of the present invention, any one or more features of any embodiment of the present invention may be combined with any one or more other features of any other embodiment of the present invention. Furthermore, the present invention is not limited to the embodiments described for illustrative purposes and should be defined solely by a fair reading of the claims appended to this patent application, encompassing the full scope of the equivalents given to each element thereof.

[0242] Some embodiments of a sensing Foley catheter system include sterilizing the collection chamber itself or other components of the system using UV light or light of an appropriate wavelength. The UV light source may be directed through the walls of the collection chamber, or the UV light source may be placed inside the collection chamber. The UV light source may be used to sterilize the collection chamber when it is empty, filled, or partially filled. The UV sterilization process may occur continuously or intermittently. The UV light source may be placed at any point in the sensing Foley catheter system. Spectroscopy - Spectrophotometry

[0243] Some embodiments of sensing Foley catheter systems involve using light wavelengths in the range of approximately 520 nm to 650 nm to identify bacteria, red blood cells, and / or plasma / leukocytes. See the area within the ellipse in Figure 61.

[0244] Some embodiments of sensing Foley catheter systems include combining spectrophotometric methods for identifying leukocytes and bacteria with the identification of decreased PO2 and / or increased CO2 for identifying infection.

[0245] Some embodiments of sensing Foley catheter systems include a controller that filters urine volume data to compensate for an increase in urine volume immediately after diuretic administration. Urine volume typically increases immediately after diuretic administration. However, in some cases, it is advantageous to essentially ignore the increase in urine volume data associated with diuretic administration. The controller of a sensing Foley catheter system can automatically ignore urine volume data associated with diuretic administration by identifying the shape of the urine volume curve associated with diuretic administration and subtracting and / or ignoring the data associated with this increase. The identification of the curve shape may be performed by the slope, length of the increase, amplitude of the increase, shape, etc. Subtracting urine volume data induced by diuretics may be advantageous in determining or predicting the onset of AKI. See Figure 62. For example, if urine volume rises above approximately 2,000 ml / hour (peak), the controller may identify this as a situation in which a diuretic was administered.

[0246] An increase in urine volume caused by the administration of diuretics may differ from an increase in urine volume caused by constriction or other obstruction of the urinary tube and / or Foley catheter. When the drainage lumen is constricted, the urine volume before the increase will be basically zero or very low, such as less than 5 ml / hour. On the other hand, when a diuretic is administered, the urine volume immediately before administration may be very low, but it is likely to be higher than zero, for example, exceeding about 5 ml / hour. Also, when the drainage lumen is constricted, the increase in urine volume after the constriction is released will be relatively short-lived, for example, about 30 seconds to about 5 minutes. On the other hand, when a diuretic is administered, the increase in urine volume will be longer-lasting, for example, about 30 minutes to about 2 hours. Also, when the drainage lumen is constricted, the urine volume after the constriction is released will likely be less than about 1000 ml. On the other hand, in situations where diuretics are administered, the urine volume after diuretic administration is likely to exceed approximately 1000 ml. By using one or all of these factors in a controller, a time-course urine volume curve can be analyzed to determine when diuretics were administered, and the increase in urine volume due to diuretics can be subtracted from the urine volume shown to the user.

[0247] Thus, the controller may automatically determine when the diuretic was administered. Alternatively, the controller's user interface may include a button or other user input device (touchscreen, voice control, etc.) to indicate when the diuretic has been administered. The controller would then look for an increase in urine volume and subtract the increase due to the diuretic from the urine volume data presented to the user.

[0248] Some embodiments of a 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 combined with the controller's determination of IAP to determine APP. The controller may further automatically change fluids and / or vasopressors to raise or lower blood pressure.

[0249] Preventing water from getting into the filter / vents

[0250] Some embodiments of the sensing Foley catheter system include one or more vents and / or filters to prevent negative pressure from building up inside the Foley catheter and to prevent aspiration trauma to the bladder. The filters / vents may be located at the junction of the Foley catheter and the drainage tube, or elsewhere, such as inside the collection tube, the drainage tube, or the lumen of the Foley catheter itself, as described below.

[0251] In some embodiments, the filter / vent is designed to repel fluid, i.e., from a hydrophobic material. However, despite the use of hydrophobic materials, the filter / vent is still susceptible to wetting by fluid, particularly urine. Some embodiments include a larger lumen, or lumen region, where the filter / vent is positioned to reduce the likelihood of the fluid filling the lumen due to its surface tension. Figure 63A shows a smaller diameter lumen, and Figure 63B shows a larger diameter lumen in the vent / filter region. Note that when the vent / filter 6304 faces upward or outward, even a smaller diameter lumen can still wet the filter / vent with fluid 6202, and here a larger diameter lumen can reduce the likelihood of wetting the filter / vent.

[0252] In embodiments where the filter / vent is located at or near the junction of the Foley catheter and the drainage tube, the area below or near the filter / vent may be taped to the patient's leg to stabilize the Foley catheter once it is in place. A larger lumen tube helps prevent the filter / vent from getting wet, especially if the vent / filter is oriented away from the leg and away from the patient. In some embodiments, the vent latch may be designed so that the vent / filter faces outward when the latch or latch area is taped to the patient's leg. For example, the latch may be curved, as shown in Figure 64, or attached to a curved base, so that it can be better attached to and oriented on the patient's leg 6402.

[0253] In some embodiments, the covering area may be extended, for example, between 6 and 12 inches, and the vent / filter may be positioned further away from the patient, so that it can be easily positioned in a location and manner that prevents wetting.

[0254] In some embodiments, the vents / filters may be located at multiple positions within the cuff or elsewhere near the diameter of the drainage lumen. Alternatively, the vents may surround all or most of the lumen. In these embodiments, the vents are surrounded by a cuff or other reinforcement to provide structural integrity to the lumen. The filters / vents may be positioned along the length of the drainage tube.

[0255] The embodiment shown in Figure 65 will also prevent wetting of the vent / filter. This embodiment includes a vent tube 6502 with an inner lumen that connects to the drainage pipe lumen 6504 near the area 6506, and is replaced with air or other air / gas / fluid along the vent tube and / or near the other end via one or more filters / vents 6508. The filters / vents may be located inside the collection pipe, as shown in Figure 65, or at other locations such as at a distance from the collection pipe.

[0256] The vent lumen may be incorporated into the drainage lumen either along the ureteral lumen or within the ureteral lumen. Alternatively, the vent lumen may be separate from the drainage lumen and connected to the drainage lumen at a vent tube / drainage tube junction, for example, near the overlapping region 6506.

[0257] The embodiment shown in Figure 66 illustrates a sensing Foley catheter system comprising a positive pressure vent tube 6602 having an inner lumen that is in fluid communication with a urinary duct lumen 6604 and a pump 6606. The positive pressure vent tube may be provided with filters 6612 along its length, in series, or at any other arbitrary location. The positive pressure vent tube may be provided with vents at any end of the tube, at any location along the tube, or with a plurality of vents.

[0258] The pump draws negative pressure over the ureteral lumen and pumps positive pressure back into the atmosphere, while the positive pressure is pumped back into the ureteral lumen via a positive pressure tube. Alternatively, different pumps may be used for negative and positive pressure. In this way, precise negative or positive pressure can be controlled at the junction 6608 between the ureteral lumen and the positive pressure vent tube. The pressure at the junction 6608 is slightly negative or neutral to prevent fluid flow from returning into the Foley catheter. For example, the pressure at the junction may be maintained at approximately 0 mmHg. Alternatively, the pressure at the junction may be maintained at approximately -2 mmHg. A selective regulator 6610 may control the negative pressure relative to the positive pressure in terms of magnitude, timing, etc. For example, the regulator (which is controlled by the controller) may implement a slight delay so that negative pressure is first drawn over the ureteral line, and then, after a set time or when a specific negative pressure is achieved, positive pressure is applied to the positive pressure tube and finally to the positive pressure tube / drainage tube junction. This would prevent the net pressure at the junction of the positive pressure tube / drainage tube from becoming positive, thus preventing urine from flowing into the bladder instead of being expelled from it. The selective regulator may also be in the form of a vent of specific dimensions (to increase resistance, use a filter material with a smaller surface area and higher density; to decrease resistance, use a filter material with a larger surface area and lower density). The positive pressure vent tube may be connected to the ureteral lumen via a valve such as an umbrella valve with a set crack pressure.

[0259] Alternatively, the positive pressure tube may be compressed by a compressed sterilizing fluid / gas / air.

[0260] Furthermore, by precisely controlling the negative pressure applied to the bladder, it is possible to replicate the normal filling and emptying of the bladder. For example, a neutral or zero pressure may be maintained, or a slight positive pressure may be maintained at the base of the Foley catheter for a certain period of time, so that the bladder can fill normally. After a set period, or after reaching a certain pressure (i.e., the pressure required to maintain neutral pressure at the base of the Foley catheter), this pressure is reduced to empty or empty the bladder. This process can be controlled by a controller that controls the pressure regulator to replicate the normal filling and emptying of the bladder by repeating this process.

[0261] In some embodiments, a valve may be used as the base of a Foley catheter to allow for better control of the pressure in that region, including the pressure (negative or positive) applied to the bladder.

[0262] The positive pressure tubing embodiment may be used with any embodiment of a sensing Foley catheter system, including those with a different filter / vent configuration than those shown herein. Furthermore, any embodiment of airlock prevention may be used with a regulator, i.e., a non-sensing Foley catheter or other catheter or drainage tube.

[0263] Figures 67 to 86 are enlarged views of region X in Figure 66, illustrating examples of different embodiments of this region.

[0264] In the embodiment shown in Figure 67, a valve 6702, such as an umbrella valve with set crack pressure, is located between the lumen of the positive pressure vent tube 6602 and the urinary lumen 6604. This valve may be a one-way valve. The vent 6704 is located between the positive pressure vent tube and the atmosphere. Configurations with only a vent or only a valve may also exist. The opening 6706 is in fluid communication with the urinary lumen 6604 and the chamber 6714 (the valve 6702 periodically interrupts fluid communication to the chamber). The chamber 6714 is in fluid communication with the lumen of the positive pressure vent tube 6602. Positive pressure is applied periodically or continuously through the positive pressure lumen 6702, and / or negative pressure is applied to the urinary lumen 6604. When the crack pressure of valve 6702 is excessive, a fluid, preferably a gas, flows through valve 6702, through the opening 6706, and through the lumen of the urinary duct lumen 6604. This serves both to clean the line of airlock or any obstruction and to clean the chamber 6714 from any fluid, reducing the possibility of wetting the vent 6704. It also serves to clean the vent 6704 if it does get wet. The crack pressure of valve 6702 refers to the pressure difference between the positive pressure lumen 6702 and the urinary duct lumen 6604. When the pressure in the urinary duct lumen falls below the pressure in the positive pressure lumen by the crack 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 crack pressure may be less than about 1 mmHg. Alternatively, the crack pressure may be less than about 2 mmHg. Alternatively, the crack pressure may be less than approximately 3 mmHg. Alternatively, the crack pressure may be less than approximately 4 mmHg. Alternatively, the crack pressure may be less than approximately 5 mmHg. Alternatively, the crack pressure may be less than approximately 10 mmHg.

[0265] The pressure in the ureteral lumen may be approximately -5 mmHg periodically or continuously. Alternatively, the pressure in the ureteral lumen may be approximately -7 mmHg periodically or continuously. Alternatively, the pressure in the ureteral lumen may be approximately -10 mmHg periodically or continuously. Alternatively, the pressure in the ureteral lumen may be approximately -15 mmHg periodically or continuously. Alternatively, the pressure in the ureteral lumen may be approximately -20 mmHg periodically or continuously. Alternatively, the pressure in the ureteral lumen may be approximately -25 mmHg periodically or continuously. Alternatively, the pressure in the ureteral lumen may be approximately -30 mmHg periodically or continuously.

[0266] The positive pressure in the positive pressure lumen may be approximately 5 mmHg periodically or continuously. Alternatively, the positive pressure in the positive pressure lumen may be approximately 7 mmHg periodically or continuously. Alternatively, the positive pressure in the positive pressure lumen may be approximately 10 mmHg periodically or continuously. Alternatively, the positive pressure in the positive pressure lumen may be approximately 15 mmHg periodically or continuously. Alternatively, the positive pressure in the positive pressure lumen may be approximately 20 mmHg periodically or continuously. Alternatively, the positive pressure in the positive pressure lumen may be approximately 25 mmHg periodically or continuously. Alternatively, the positive pressure in the positive pressure lumen may be approximately 30 mmHg periodically or continuously.

[0267] The vent may be additional or alternative to those located elsewhere along the positive pressure vent tube, for example, near the pump or as part of the pressure regulator. A second vent / valve assembly 6708 is shown on the attachment in Figure 67, but this second vent / valve assembly may or may not be present. A selective thermistor 6710 and a selective pressure lumen 6712 are also shown. Alternatively, the positive pressure vent tube may be exposed to atmospheric pressure.

[0268] Figure 68 shows one embodiment of a constricted area including a vent 6802, a valve 6804, and a small cross-sectional area 6806 that is large enough to allow air / gas to flow freely from the vent into the ureteral lumen, but small enough to prevent liquid from flowing into the vent. For example, the constricted portion 6806 may have a diameter of less than about 1 mm. Or the constricted portion may have a diameter of less than about 2 mm. Or the constricted portion may have a diameter of less than about 3 mm. Or the constricted portion may have a diameter of less than about 4 mm. Or the constricted portion may have a length of about 1 mm to 5 mm. Or the constricted portion may have a length of 5 mm to 30 mm. The embodiment shown in Figure 68 may or may not include a positive pressure tube, but is shown as not including a positive pressure tube (i.e., exposed to the atmosphere). This embodiment may or may not include this valve.

[0269] Figure 69 shows one embodiment of a vent area comprising a vent 6902 and a long vent tube 6904 that is long enough to allow air / gas to flow freely from the vent into the urinary duct lumen but to prevent liquid from flowing into the vent. For example, the vent tube portion 6904 may have a diameter of about 1 to 10 mm and a length of about 1 to 10 cm. For example, the vent tube portion 6904 may be longer than about 2 cm. Alternatively, the vent tube portion 6904 may be longer than about 4 cm. Alternatively, the vent tube portion 6904 may be longer than about 10 cm. The embodiment shown in Figure 69 may or may not include a positive pressure tube, but is shown as one without a positive pressure tube. This embodiment may or may not include this valve.

[0270] Figure 70 shows one embodiment of a covered area including a vent 7002 and a long meandering vent tube 7004 that allows air / gas to flow freely from the vent into the urinary duct lumen but has enough meandering to prevent liquid from flowing into the vent. For example, the vent tube portion 7004 may be a coil. The embodiment shown in Figure 70 may or may not include a positive pressure tube, but is shown as not including one. This embodiment may or may not include a valve.

[0271] Figure 71 shows one embodiment of a region including a vent 7102 and a compact, meandering vent tube 7104 that allows air / gas to flow freely from the vent into the urinary duct lumen but has sufficient meandering to prevent liquid from flowing into the vent. For example, the vent tube portion 7104 may be a tube with a baffle or mesh inside the inner lumen. The embodiment shown in Figure 71 may or may not include a positive pressure tube, but is shown as not including one. This embodiment may or may not include a valve.

[0272] Figure 72 shows one embodiment of a fitting region including a vent 7202 and a vent tube 7204. In this embodiment, the vent tube is in fluid communication with the positive pressure tube 7206, and the vent 7202 is aligned with the positive pressure lumen so that fluid under positive pressure passes through / crosses the vent and enters the drainage lumen through the opening 7208. The vent tube 7204 is shown here in a coiled shape to help prevent backflow of urine into the vent tube, but the vent tube 7204 may be in any configuration, including a straight pipe or a lumen embedded within the fitting region. The vent 7202 is shown here near the junction of the vent tube 7204 and the positive pressure tube 7206, but the vent may be at any location 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.

[0273] Figures 73A and 73B show one embodiment of a support area including a vent 7302 and a compact, meandering vent tube 7304 that allows air / gas to flow freely from the vent to the urinary duct lumen but has sufficient meandering to prevent liquid from flowing into the vent. The vent end of the vent tube 7304 may be configurable, bendable, or deformable so that it can be oriented upward after the support area is fixed to the patient's leg. Orienting the vent end of the vent tube upward reduces the opportunity for the vent to be exposed to liquid. For example, the vent tube portion 7304 may basically be a flattened coil. The embodiment shown in Figure 73 may or may not include a positive pressure tube, but is shown as not including one. This embodiment may or may not include a valve 7306.

[0274] Figure 74 shows one embodiment of a covering area including a plurality of vents 7402 and a selective valve 7404. The plurality of vents reduces the chance that all vents will become wet with urine. The plurality of vents may be any preferred configuration, including lines, circles, etc. The plurality of vents may be located on one side of the covering area, or may partially or completely surround the covering area. For example, there may be two vents, or for example, three vents, or for example, four vents, or for example, five vents, or for example, six vents, or for example, seven vents, or for example, eight vents, or for example, nine vents, or for example, ten vents. The embodiment shown in Figure 74 may or may not include a positive pressure tube, but is shown as not including a positive pressure tube. This embodiment may or may not include a valve.

[0275] Figure 75A shows one embodiment of a region that does not have a relay over the vent but may still have one or more vents. In this embodiment, the positive pressure tube 7502 is in fluid communication with the urinary tract lumen via an opening 7504. The valve is preferably a pressure-sensitive valve 7506, which is located 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 Figure 75A as an inflatable valve, such as an annular balloon (also shown in Figure 75B). The valve 7506 may be inflated via the same pressure source connected to the positive pressure tube 7502 or via a separate pressure source. The valve 7506 may be in fluid communication with the lumen of the positive pressure tube 7502, as shown herein, or may be inflated via a separate positive pressure lumen.

[0276] In this embodiment, valve 7506 closes when positive pressure is periodically applied to the drainage lumen via the positive pressure tube 7502. Closing the valve prevents air or positive pressure from reaching the bladder and allows the positively pressurized fluid (gas or liquid) to purify the drainage lumen. When the positive pressure in the positive pressure tube decreases, the valve opens, allowing urine to be discharged from the bladder again. A small amount of positive pressure may be maintained in the positive pressure tube to offset the negative pressure in the urination line. If higher pressure is required to purify the airlock line, valve 7506 closes while the higher pressure flows in a burst.

[0277] Figure 76 shows an embodiment similar to that shown in Figure 75, but in this embodiment, valve 7602 is a passive mechanical valve. Valve 7602 is normally in a flat or open position. When the positive pressure in the positive pressure tube becomes higher than any negative pressure in the drainage tube lumen, the valve automatically closes to prevent the fluid / positive pressure from transferring to the patient's Foley catheter / bladder.

[0278] Alternatively, a venturi may be used to control the negative or positive pressure radiating towards the application area, similar to a vehicle's carburetor.

[0279] Figures 77A and 77B show other embodiments using a more active valve system. This embodiment comprises a suction chamber 7702, a flexible portion 7704, a patient-side valve 7706, a drain-side valve 7708, a drain lumen inlet 7710, and pressure lines 7712, 7714, 7716, and 7718.

[0280] Both the patient-side valve 7706 and the drainage-side valve 7708 are open in the passive or open position. That is, the balloon / bladder is not inflated, and urine can freely pass through the drainage tube lumen 7720 and the drainage tube lumen 7722 from the drainage catheter. The flexible portion 7704 is in the neutral position in the open position. In the event of an obstruction such as an airlock, or periodically to prevent obstruction, the drainage-side valve 7708 is closed by applying pressure, such as a pressurized fluid (gas or liquid), through the pressure line 7718. The flexible portion 7704 is compressed by applying negative pressure through the pressure line 7716. The pressure line 7714 remains neutral or closed. The pressure line 7712 remains neutral, closed, or in a negative state, completely deflating valve 7706. This configuration effectively applies negative pressure to the drainage catheter by closing off the fluid flow to the drainage line 7724 while expanding the flexible portion 7704. This configuration is shown in Figure 77A.

[0281] The configuration in Figure 77A lasts only for a short period, for example, 0.5 to 1 second, or about 1 to 3 seconds, or about 3 to 5 seconds. The patient-side valve 7706 is closed by applying positive pressure to the pressure line 7712, and the drain-side valve is opened by reducing the pressure in the pressure line 7716 to neutral or by applying negative pressure to the pressure line 7716. The volume of the flexible portion 7704 is reduced by raising the pressure in the pressure line 7718 to neutral or by applying positive pressure to the pressure line 7718. Positive pressure may also be applied to the pressure line 7714. This configuration is also shown in Figure 77B. In this configuration, the fluid in the drainage lumen 7720 and the drain line 7724 is pushed by the positive pressure applied through the pressure line 7714 and / or by the reduction in the volume of the flexible portion 7704, effectively pushing the urine through the drain line. After flushing, the system opens both the patient-side valve 7706 and the drain-side valve 7708, and the flexible portion 7704 is in the neutral position.

[0282] Figure 78 shows an embodiment similar to that shown in Figure 72, but with a positive pressure vent tube 7802 and without a separate vent tube. The vent 7804 is in fluid communication with and parallel to the lumen of the positive pressure vent tube 7802. The vent 7804 is also in fluid communication with the area of ​​the urinary duct lumen 7808 and is connected to the area 7808 by an opening 7806. Fluid / air / gas under positive pressure crosses the vent 7804 and enters the area 7808, which is in fluid communication with the drainage lumen, through the opening 7806. In other words, fluid / air / gas with positive pressure crosses the filter and enters the interior of the area of ​​the area of ​​the area of ​​the area of ​​the area of ​​the area of ​​the area of ​​the area of ​​the area of ​​the area of ​​the area of ​​the area of ​​the area of ​​the area of ​​the area of ​​the area of ​​the area of ​​the area of ​​the area of ​​the area of ​​the area of ​​the area of ​​the area of ​​the area of ​​the area of ​​the area of ​​the area of ​​the area of ​​the area of ​​the area of ​​the area of ​​the urinary duct lumen 7808. The vent 7804 may be located at any point along the length of the positive pressure vent tube 7802. The embodiment shown in Figure 78 may or may not include a one-way valve between the filter and the opening. Positively pressurized fluid / air / gas may pass through the vent continuously, intermittently, sporadically, etc. Positively pressurized fluid / air / gas may pass through the vent as a stream, a spurt, or a pulse.

[0283] Figure 79 shows one embodiment in which the region within the attachment that is in fluid communication with the ureteral lumen has a larger volume. Fluid such as urine 2902 flows from the drainage catheter into a larger container 7904 and then into the ureteral lumen. Container 7904 is large enough that it is not likely to be completely filled with liquid. The volume of the container that is not filled with liquid will be filled with air or gas. A one-way valve 7908 may also be present. Because container 7904 always has some air / gas inside, the vent 7906 may be positioned so as not to come into contact with the urine / fluid in the container. In other words, the vent may be on the side of the air bubbles in the container. There may be more than one number of vents to ensure that at least one vent is always in fluid communication with the air bubbles in the container. In some embodiments, the volume of container 7904 may be larger than the volume of the inner lumen of the drainage tube.

[0284] Figures 80A and 80B show one embodiment in which the area of ​​the vent is very large. Here, the vent 8002 is shown as a large, flat circle or disc, but the vent may be of any shape and size. The vent may be flat or curved, such as by curving around the area of ​​contact. The embodiment described herein is shown with one opening 8004 and a one-way valve 8006, but other embodiments may have more than one opening and may or may not have a valve. In some embodiments, about 1 cm 2 It may have a filter surface area greater than . 2 It may have a filter surface area greater than this. In some embodiments, about 3 to about 4 cm 2 It may have a filter area of ​​about 2 to about 4 cm. Alternatively, in some embodiments, it may have about 2 to about 4 cm. 2 It may have a filter surface area of ​​about 4 to about 6 cm². Alternatively, in some embodiments, it may have about 4 to about 6 cm². 2 It may have a filter surface area of ​​about 6 to about 10 cm². Alternatively, in some embodiments, it may have about 6 to about 10 cm². 2 It may have a filter surface area.

[0285] Figure 81 shows one 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, but embodiments without a positive pressure tube and / or valve may exist. The replaceable vent 8102 may be provided via a mounting mechanism such as a Luer lock, snap lock, slide-in lock, press-fit, or any other suitable mechanism. Vent replacement may be performed periodically, once a day, or as needed, such as when the user is warned that the vent is no longer functioning properly, or when the user is notified that the vent is no longer working. The vent may be chemically sensitive to urine or components of urine and may change color to indicate wetting. For example, pH-sensitive or other chemical or attribute-sensitive paper may be used for the replaceable vent, which changes color to make it visible to the user. The replaceable vent may be disposable.

[0286] Figures 82A and 82B show one embodiment in which the filter is flexible. In this embodiment, the filter 8202 may be flexible or deformable, i.e., convex / concave, and may be loosened within its housing. Movement of the flexible filter 8202 may help to remove the filter if it becomes wet or contaminated. Movement of the filter may be controlled by positive pressure via the positive pressure tube 8204, negative pressure via the ureteral lumen, a valve 8206, or any one or a combination of the above. Some embodiments may also include a mechanical mechanism for agitating, shaking, vibrating, bending, and / or moving the filter 8202. Figure 82A shows, for example, an example of one embodiment in which negative pressure in the ureteral lumen causes the filter to become concave. Figure 82B shows the same example after positive pressure has been applied to the vent via the positive pressure tube 8204. The pressure inside the vent housing 8208 may be controlled by the crack pressure of the one-way valve, or by the relative negative and positive pressures in the urinary duct lumen and positive pressure tube. Similar embodiments may also exist in which the filter is not flexible, but the filter is kept dry by controlling the pressure inside the vent housing 8208 in a similar manner.

[0287] Alternatively, the filter (which may be flexible or otherwise) may be wiped or rubbed mechanically, either manually or automatically. Alternatively, the filter may contain an agent that does not promote protein adhesion and / or growth, such as an enzyme detergent. Alternatively, the filter may contain an agent that does not promote biofilm formation, such as an antimicrobial agent.

[0288] Figure 83 shows one embodiment with multiple layers of filters. Filters with different pore sizes may be used in stacking. For example, a coarser pore filter 8304 may protect a fine pore filter 8302. The coarser pore filter 8304 may be placed between the fluid / urine and the fine pore filter 8302. In this configuration, the liquid / urine would need to pass through the coarser filter 8304 to come into contact with the fine filter 8302. More than two filters with stepped pore sizes, similar pore sizes, or any number of pore sizes can be stacked in this manner. For example, very fine pore filters may be stacked so that the finer pore filters are further away from the urine / liquid. Alternatively, one or more coarser pore filters of the same or different pore sizes may be placed between the urine / liquid and the fine pore filters. A one-way valve may or may not be present. The pore size of the coarser pore filter 8304 may be about 10 microns. Alternatively, the pore size of the coarser pore filter 8304 may be approximately 10 to 20 microns. Alternatively, the pore size of the coarser pore filter 8304 may be approximately 10 to 30 microns.

[0289] Figure 84 shows one embodiment in which a fluid in a positive pressure tube applies continuous positive pressure to a pressure zone. The positive pressure tube is under substantially constant positive pressure so that the fluid (preferably air / gas) continuously passes through the opening 8404. The positive pressure applied to the fluid inside the pressure zone 8406 is controlled so that the fluid does not flow back into the urinary catheter. In other words, the negative pressure applied to the fluid inside the inside 8406 is always greater than or equal to the positive pressure applied to the fluid inside the inside 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. Or the diameter of the opening 8404 may be less than about 2 mm. Or the diameter of the opening 8404 may be less than about 3 mm. Or the diameter of the opening 8404 may be less than about 4 mm.

[0290] Figure 85 shows an embodiment with an accordion-shaped vent. In this embodiment, the vent 8502 has an accordion-like shape. The vent may be compressed in the direction of the two-way arrow. This compression may protect the vent from clogging / wetting, etc. Compression may be performed manually, automatically / mechanically, and / or using pressure (negative and / or positive pressure) within the vent area.

[0291] Figure 86 shows one embodiment with a single vent and multiple openings. In this embodiment, more than one small opening 8602 separates the ureteral lumen from the vent 8604. The small openings prevent fluid from coming into contact with the vent 8604. The multiple openings may function as redundancy, so that if one or more openings become blocked, the others remain open. The openings may be used to control the flow path of air / gas / fluid through the vent 8604, with a greater number of holes reducing resistance to airflow and a smaller number of holes increasing resistance to airflow.

[0292] Any embodiment described herein may include physiological pressure measurement or may be used without physiological pressure measurement. For example, the systems shown in Figures 67 to 86 and other embodiments may not include a thermistor or pressure lumen and may be used with a standard Foley catheter.

[0293] In some embodiments, the pressure may be measured at the junction of the positive pressure tube / drainage tube. Alternatively, the pressure may be measured within the junction or engagement area of ​​the sensing Foley catheter / drainage tube. The pressure may also be measured at either of these locations by incorporating an additional tube or lumen that is in fluid communication at one end with the junction or engagement area of ​​the pressure tube / drainage tube and in fluid communication at the other end with a pressure sensor or transducer. For example, this pressure measuring lumen may be in fluid communication at one end (sensor end) with a controller housing the pressure sensor and in fluid communication at the other end (sensing end) with the junction of the positive pressure tube / drainage tube. A pressure-sensitive membrane may be present at the sensing end to prevent contamination of the lumen with urine.

[0294] Airlocks may be detected in a manner that allows for optimal cleaning and / or avoidance. By using any of the embodiments herein, the controller may apply a small positive or negative pressure to the ureteral lumen and sense the response. Since air is more compressible than urine, attenuation of the response may indicate the presence of an airlock, and a smaller attenuation of the response may indicate a smaller airlock. If an excessive airlock is detected, the controller may initiate airlock cleaning, for example, by applying negative pressure to the drainage lumen.

[0295] The vent tube may be a separate tube from the drainage tube and may be inserted into the drainage lumen or the Foley catheter. Figure 87 shows one embodiment of a sensing Foley catheter system in which the vent tube is located inside the urinary drainage tube. This type of embodiment has the advantage of being usable with any standard drainage tube. The drainage tube essentially has a vent located at some point within the drainage lumen, either inside the drainage tube or within the Foley catheter. The vent tube may be slidably inserted into the drainage tube and / or Foley catheter and may be moved as needed.

[0296] In the embodiment shown in Figure 87, the vent tube 8704 may be open at one end ("air end" 8708) to the vent / filter 8702 (open to atmospheric pressure) in the collection container, or at the other end ("urine end" 8710) in the ureteral lumen 8706. Here, the vent tube is shown extending into the engagement at the base of the Foley catheter, but the vent tube may extend to any point in the ureteral lumen, including any point in the drainage tube or Foley catheter. The vent tube may remain in one place or move within the system to maximize urination and minimize damage to the bladder caused by the airlock and negative pressure in the bladder.

[0297] Figure 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 the atmosphere at the “air end” 8806 of the tube. Filters / vents may be provided at both ends. The “air end” of the vent tube may exit the drainage tube lumen via a Y-arm adapter, stopcock, or other standard method. The “air end” of the vent tube may exit the system from within the collection tube via a channel or port incorporated within the collection tube. Again, the vent tube may be used with any urinary tube, including a standard urinary tube.

[0298] Figure 89 shows an embodiment similar to that shown in Figure 88, with the addition of a positive pressure tube 8902.

[0299] Figures 90 and 91 show vent tubes at different locations within a sensing Foley catheter system. In Figure 90, the “urinary end” 9002 of the vent tube is a partial route 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 about one-third of the way through the drainage tube. Or, for example, the vent tube may be inserted about two-thirds of the way through the drainage tube. In Figure 91, the “urinary end” 9002 of the vent tube is inside the Foley catheter. The position of the “urinary end” of the vent tube is determined based on maximizing urination, minimizing the airlock effect on drainage, and minimizing negative pressure in the bladder.

[0300] The vent tube may incorporate one or more filters / vents. The vent tube may incorporate one or more notches that are in fluid communication with the inner lumen of the vent tube and ultimately in fluid communication with the vent / filter either inside the collection container or elsewhere. Multiple filters / vents or multiple notches may be provided around the vent tube, along it, or both. The vent tube also contains UV light directed towards the filter, the "urine end," or other locations to maintain a sterile state.

[0301] Figures 92A and 92B illustrate several possible embodiments of a drainage lumen, such as the drainage lumen 1012 shown in Figure 10A. Figure 92A shows a drainage lumen with a collapsible / expandable portion 9202. The portion 9202 may be manufactured from a material with a lower durometer than the rest of the drainage lumen, allowing it to be collapsed or expanded depending on the internal pressure. The lumen will collapse into a lower internal region / volume at lower pressures or negative pressures and expand at higher pressures or positive pressures. The airlock may be reduced by this change in lumen volume at different pressures. This type of lumen may be incorporated into any of the embodiments herein.

[0302] Figure 92B shows one embodiment of a drainage lumen comprising two lumens. The inner lumen shown in the figure is the negative pressure / urination lumen 9204. The outer lumen is the positive pressure lumen 9206. An opening 9208 is provided between these two lumens. The opening may or may not be equipped with a filter membrane. The two lumens may be concentric or adjacent, as shown in the figure. The positive pressure lumen essentially performs the same function as the positive pressure vent tubes shown elsewhere in this specification. When negative pressure is applied to the drainage lumen 9204, positive pressure is applied to the positive pressure lumen 9206 constantly or periodically, resulting in the removal of the drainage lumen 9204.

[0303] Figures 93A to 93E show other embodiments of the drainage lumen. This embodiment also comprises a drainage lumen 9302 and a positive pressure lumen 9304. In this embodiment, the positive pressure lumen 9304 is expandable and compressible. When compressed, the positive pressure lumen partially or completely shields the drainage lumen. When compressed, the positive pressure 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 side of the drainage tube. Figure 93B shows the drainage lumen in a closed state away from the patient. Figure 93C shows the drainage lumen in an open state.

[0304] Figure 93D shows a longitudinal view of the drainage lumen in a closed state. Figure 93E shows a longitudinal view of the drainage piping in an open state. In the open state, as shown in Figures 93C and 93E, the positive pressure lumen 9304 is compressed and does not substantially obstruct the drainage lumen 9302, allowing urine to flow freely from the body to the container. When an airlock or other obstruction is removed in the drainage tube, the positive pressure lumen is inflated and pushes the urine / liquid down the drainage tube toward the collection container. The patient end 9306 of the positive pressure lumen may have a larger diameter and / or lower durometer than the container end 9308 of the positive pressure lumen. This causes the patient end of the positive pressure lumen to inflate before the container end inflates. In this way, after the drainage lumen is initially obstructed in the immediate vicinity of the patient, the inflation of the remaining portion of the positive pressure lumen fills either substantially all or part of the drainage lumen. The positive pressure lumen may be inflated at either the patient end or the container end of the drainage tube. One or more filters may be present along the length of the drainage lumen.

[0305] Embodiments of a sensing Foley catheter system may be capable of measuring pressure within the bladder via a pressure balloon connected to the Foley catheter, or via a pressure balloon or other pressure sensor inserted into the drainage tube and / or the drainage lumen of the Foley catheter. See, for example, Figures 94A to 94C.

[0306] Figures 94A to 94C show embodiments of a sensing Foley catheter system in which the pressure sensor is in fluid communication with the ureteral lumen of the Foley catheter, but may be mounted on a separate catheter. The Foley-type catheter 9402 is shown to have a ureteral lumen 9404 and a urination opening 9406. A small pressure-sensitive catheter 9408 with a pressure-sensitive balloon 9410 is shown inside the ureteral lumen of the Foley-type catheter. The outer diameter of the pressure-sensitive catheter is small enough to fit inside the ureteral lumen of the Foley-type catheter. For example, the outer diameter of the pressure-sensitive catheter may be less than about 4 mm, or less than about 3 mm, or less than about 2 mm, or less than about 1 mm.

[0307] The pressure sensor on the pressure catheter may be located near the distal end of the pressure catheter, or at any point along the length of the catheter. The pressure sensor may be a pressure balloon, or any type of pressure sensor such as a piezoelectric sensor or mechanical sensor. In the case of a pressure balloon, the inflated balloon may be smaller than the inner diameter of the ureteral lumen of the Foley-type catheter, or it may be large enough to fill the ureteral lumen of the Foley-type catheter.

[0308] The inflated pressure balloon may be used to fill the ureteral lumen of a Foley-type catheter, thereby enabling better pressure measurement. The pressure balloon may be periodically deflated or partially deflated to allow urine to flow from the bladder through the Foley-type catheter. The inflation cycle of the pressure balloon is controlled by the controller of the present invention.

[0309] Figure 94B shows an embodiment of a pressure-sensitive catheter having both an occlusion balloon 9424 and a pressure-sensitive balloon 9426. The occlusion balloon occludes the ureteral lumen so that the pressure-sensitive catheter senses only the pressure between the occlusion balloon and the bladder, thereby allowing for more accurate and precise measurement of the pressure within the bladder.

[0310] The outer diameter of the inflated pressure balloon may be less than approximately 5 mm, or the outer diameter of the pressure catheter may be less than approximately 4 mm, or the outer diameter of the pressure catheter may be less than approximately 3 mm, or the outer diameter of the pressure catheter may be less than approximately 2 mm, or the outer diameter of the pressure catheter may be less than approximately 1 mm.

[0311] Figure 94C shows a standard Foley-type catheter with a retention balloon 9412, a urination opening 9406, a retention balloon port 9414, and a urination port 9416. An adapter 9418 connected to the urination port 9416 is shown. The adapter 9418 has two ports, namely a urination port 9420 and a secondary ureteral lumen port 9422. A pressure-sensitive catheter 9408 is shown within the ureteral lumen port 9422. Thus, the pressure-sensitive catheter is in fluid communication with the ureteral lumen of the Foley-type catheter. The proximal end of the pressure-sensitive catheter 9408 is connected to a pressure sensor, such as a pressure transducer, as in other embodiments herein. The pressure-sensitive catheter 9408 may have only a single lumen and this sensing balloon lumen, or it may include other lumens. If the pressure sensor of the pressure-sensitive catheter is a mechanical pressure sensor, the pressure-sensitive catheter does not need to have a lumen, or it may have a balloon for sealing the ureteral lumen of a Foley-type catheter.

[0312] The pressure-sensitive catheter may be inserted through the ureteral lumen of the drainage tube.

[0313] Pressure measurements are performed over time using a pressure-sensitive catheter and can be analyzed by any of the methods disclosed herein. To improve pressure measurement, the drainage port 9420 may be periodically closed or shielded. Shielding of the drainage port 9420 may be performed mechanically by a stopcock or valve, or automatically by, for example, a solenoid valve connected to a controller. An advantage of this embodiment is that the pressure-sensitive catheter 9408 can be used in conjunction with a Foley-type catheter to measure pressure. Furthermore, the pressure-sensitive catheter 9408 can be inserted into and removed from the Foley-type catheter after the Foley-type catheter has already been positioned in the patient's bladder.

[0314] The pressure-sensitive catheter may be combined with a vent tube as shown in other figures. Thus, the pressure-sensitive, urination, airlock prevention, and vent components of the pressure-sensitive Foley catheter system can be used with any standard Foley catheter and drainage tube. Alternatively, the pressure-sensitive catheter / vent tube combination may be used with more specialized Foley catheters and / or drainage tubes.

[0315] In some embodiments equipped with any type of airlock cleaning mechanism, airlock cleaning may be performed continuously, periodically, on demand, or when airlock conditions are sensed. The airlock cleaning mechanism prevents or reduces airlocks. For example, the airlock cleaning mechanism may reduce airlocks so that they are removed at least every 60 minutes. Or the airlocks may be removed at least every 45 minutes. Or the airlocks may be removed at least every 30 minutes. Or the airlocks may be removed at least every 20 minutes. Or the airlocks may be removed at least every 10 minutes. Or the airlocks may be removed at least every 5 minutes. Or the airlocks may be removed at least every 1 minute.

[0316] In any embodiment comprising a vent, filter, or vent tube as part of the area or drainage tube, the fluid (i.e., urine) waveform may be discontinuous, i.e., interrupted, due to the gas / air introduced into the drainage lumen via the vent / filter / vent tube. In other words, the drainage lumen may alternate between liquid (i.e., urine) and gas.

[0317] In any embodiment comprising real-time measurement of urine volume, real-time means that the reported urine volume measurement has an accuracy of approximately 1 minute or less. Alternatively, real-time means that the reported urine volume measurement has an accuracy of approximately 5 minutes or less. Alternatively, real-time means that the reported urine volume measurement has an accuracy of approximately 10 minutes or less. Alternatively, real-time means that the reported urine volume measurement has an accuracy of approximately 20 minutes or less. Alternatively, real-time means that the reported urine volume measurement has an accuracy of approximately 30 minutes or less. Alternatively, real-time means that the reported urine volume measurement has an accuracy of approximately 60 minutes or less.

[0318] Air bubbles in urine are prevented from forming and / or affecting the measurement.

[0319] In some cases, proteins or other components in the urine may cause excessive bubbles in the drainage tube lumen and / or urine in the collection tube, leading to problems such as wetting the vent / filter, urine entering the overflow area of ​​the collection tube, and inaccurate measurements. Some embodiments of sensing Foley catheter systems incorporate bubble prevention mechanisms.

[0320] In some embodiments, the pressure within the urinary tract can be precisely controlled, such as by incorporating a positive pressure tube. By occasionally applying a small amount of positive pressure to the drainage system (i.e., the drainage tube lumen and / or collection chamber), any existing air bubbles can be crushed, and their formation can be prevented.

[0321] Surfactants such as silicone may be added to the system. For example, slow-dissolving silicone capsules may be added to the collection container. Alternatively, a surfactant coating may be used inside the drainage tube lumen and / or inside the collection tube.

[0322] Bubbles may be eliminated or reduced at the joint between the discharge pipe and the collection pipe. Several embodiments are shown in Figures 95A to 95C. For example, the base of the drain pipe may be S-shaped (like a drain under a sink), and the inner diameter of the drain pipe may be expanded to near the joint with the collection pipe or other locations. The drain pipe may be bulb-shaped or conical. The discharge lumen may be annular, as shown in Figure 95C. In this embodiment, the fluid is flowed down the side of an inclined conical surface, similar to how beer is reduced from foaming when it flows down the side of the glass rather than the center. Here, the bubble reduction feature is shown at the base of the drain tube, but it may be at any part of the drain tube or system. In some embodiments, the drain lumen may be flattened to allow urine to come into contact with the surface again. For example, the urinary lumen may be flattened to less than about 1 mm. The urinary lumen may be flattened to less than about 2 mm. The ureteral lumen may be flattened to less than approximately 3 mm.

[0323] Urine may also be allowed to flow to the apex, as shown in Figure 96A with an embodiment of an inverted cone. This cone may be angled, as shown in the same figure, but may be more curved. The conical shape typically transitions from a small area to a large area and / or from a large area to a small area. This bubble reduction mechanism and other bubble reduction mechanisms may be located inside the collection tube. For example, as shown in Figures 96B to 96D, an angled baffle may be incorporated into the collection container to allow the fluid to flow off the angled surface. The angled surface may extend over the entire length of the collection tube to the bottom, or it may extend only partially into the collection tube. Different angles may be used, for example, angles of about 10 degrees to about 80 degrees.

[0324] Angled baffles, as shown in the embodiments in Figures 96C and 96D, may be suitable for improving the accuracy of urine volume measurement, especially in critical care situations, where continuous measurement of urine volume (ml / min or ml / second) is desirable for diagnosing a patient's vulnerability to AKI, sepsis, or other conditions when the patient's urine output is low. For accurate measurement of small amounts of urine, conical or angled baffles allow for better measurement compared to flat-bottomed baffles or cassettes because the height of the urine column is greater relative to the given urine volume. An ultrasonic transducer or similar transducer on the controller can more easily measure the height, allowing for accurate measurement of urine volume and urine volume ratio, especially when the patient's kidneys are damaged and can produce little urine. Angled baffles or cassettes (urine collection chambers) may also have lower sensitivity to changes in the controller's tilt angle, and may reduce measurement errors for small amounts of urine compared to cassettes with a flat surface.

[0325] Figure 97A shows one embodiment of a sensing Foley catheter system in which a drainage lumen extends into the collection tube / cassette so that the fluid is normally discharged into the collected fluid below the fluid level. The drainage end of the drainage lumen is cut at a certain angle to prevent the piping from contacting the bottom of the cassette and obstructing the fluid flow. The angle cut 9724 may be about 45 degrees, about 10 to 80 degrees, or any preferred angle. The same result may be achieved by using other shapes at the drainage end of the drainage lumen. For example, Figure 97B shows a drainage lumen in which the piping is castellated at the drainage end. This castellation 9726 may be any shape, including round, square, triangular, shell-shaped, etc.

[0326] Figure 97C shows one embodiment of a sensing Foley catheter system in which the drainage lumen extends into a cassette and includes a flattened region 9728. In this embodiment, the cross-sectional area of ​​the drainage lumen may be kept constant or increased or decreased within the flattened region, but it is desirable to increase the surface area to contact the fluid flow by at least one dimension. The flattened region may direct the flow downward, as shown in Figure 97C, or the flattened portion may have an angle that causes the fluid to flow in contact with at least one side of the inner surface of the lumen. Alternatively or additionally, an angled baffle, such as the baffle 9730 shown in Figure 97D, may be used. The angle of the baffle 9730 may be about 45 degrees, about 10 to 80 degrees, or any preferred angle. The angled baffle or flattened region may be used in conjunction with any of the drainage piping / lumen designs shown herein.

[0327] Figure 98A shows one embodiment of a sensing Foley catheter system in which the drainage lumen area increases or decreases. The bulb-shaped portion 9832 may be incorporated into the drainage piping at any point above the cassette, inside the cassette as shown in Figure 98D, or along the drainage lumen. The upper and lower areas of the bulb-shaped portion may be basically the same, or the area below the bulb-shaped portion may be smaller than the area above the bulb-shaped portion, as shown in Figure 98B. The drainage lumen area reduction portion 9834 may be relatively short; for example, portion 9834 may be about 1 mm to 10 mm in length. Alternatively, portion 9834 may be about 10 mm to 20 mm in length. Alternatively, portion 9834 may be about 10 mm in length. Figure 98C shows one embodiment in which the area reduction fluid drainage lumen has more than one narrowed section 9836. This increases surface contact of the drainage lumen without significantly reducing the area of ​​the drainage lumen. The narrowed section 9836 may be used together with the bulb-shaped section 9832, or it may be used without the bulb-shaped section.

[0328] Any of the embodiments for reducing bubbles disclosed herein may be used at any point within the drainage lumen, which includes drainage piping outside the cassette and drainage piping / lumen inside the cassette. For example, Figure 98D shows an embodiment similar to that shown in Figure 98B, in which the valve is provided inside the cassette.

[0329] Figure 99A shows one embodiment of a sensing Foley catheter system in which at least a portion of the drainage lumen disperses and / or bursts air bubbles.

[0330] Figures 99B and 99C show other embodiments of bubble reduction. In this embodiment, a grid, honeycomb structure, or mesh is provided within the base of the drainage tube. This mesh may help break bubbles and clean areas of periodically compressed fluid, and also helps break bubbles.

[0331] Alternatively or as an addition, a flat mesh may be inserted at any point in the system, for example, at the joint of the drainage tube / collection tube.

[0332] In some embodiments, the cassette and / or drainage lumen may be vibrated continuously or intermittently to break up air bubbles.

[0333] Figures 100A to 100C show embodiments in which a plate, whether floating or not, is incorporated to press and break air bubbles on or near the surface of the urine in the collection tube. The plate may simply float on the surface and passively rise and fall depending on the amount of urine in the tube, or the plate may actively move up and down. The plate may also be fixed in place. The plate may be porous or solid. In embodiments in which the plate is on the surface of the fluid, the plate may also be used to measure the urine volume. The position of the plate may be determined by ultrasound, visual means (such as a camera), laser, or other techniques. The amount of fluid in the collection tube may be determined directly from the fluid level, which can be determined from the position of the plate.

[0334] The inside of the cassette may be rectangular or have other shapes. For example, the inside of the cassette may be tapered inward towards the bottom so that the upper surface of the urine is larger relative to the amount of urine in the cassette.

[0335] In some embodiments, a volumetric baffle may be provided at a set volume mark, such as 50 ml. The volumetric baffle may be similar to the baffle 2302 shown in Figure 23, except that it will be at a predetermined volume position. The ultrasonic signal is stronger when the top surface of the urine volume in the cassette is on or near the volumetric baffle compared to when it is not. For example, the volumetric baffle may be positioned so that the top surface of the urine volume is on or near the volumetric baffle when the top surface of the urine volume is approximately 50 ml (or another set volume). The ultrasonic signal is strongest when the two surfaces (urine and volumetric baffle) are close to or in contact with each other.

[0336] Figure 101A shows one embodiment of a sensing Foley catheter system equipped with valves at both the drainage port 10102 and the entry point 10104, where the drainage piping is connected to a collection tube. This causes the controller to periodically press the collection tube, which may reduce air bubbles. This also results in more accurate measurement of urine volume, as the inflow of urine into the collection tube can be stopped by the controller while the urine is being emptied.

[0337] Figure 101B shows one embodiment of a collection tube in which the urine overflow channel is longer and / or spiral / serpentine and / or narrower. This configuration makes it more difficult for air bubbles to enter the overflow channel, resulting in inaccurate measurement of urine volume. The overflow channel may include one or more channel angles greater than 45 degrees.

[0338] Some embodiments include a drainage tube with a smaller lumen diameter. 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.

[0339] In some embodiments, the discharged urine can be used to "wash" air bubbles in the drainage tube or collection container. The urine circulates back into the drainage tube, increasing the volume in the drainage tube and helping to "wash" air bubbles in the piping and / or container. The controller compensates for the circulating urine in the urine volume calculation.

[0340] In some embodiments, pressurized air may be introduced into the drainage tube and / or collection tube. The pressurized air pops and / or compresses bubbles, pressing the urine against the surface of the system and reducing bubble formation. As the drainage tube moves to the flattened portion, the cross-sectional area of ​​the drainage tube may decrease, remain the same, or increase.

[0341] horizontalization

[0342] In embodiments that use ultrasound to measure the volume of urine in a collection tube, it is important that the ultrasound has a surface at approximately 90 degrees from the ultrasonic sensor (i.e., the surface of the urine volume). If the system is tilted even by a few degrees, the ultrasonic sensor may not be able to sense the surface of the urine, and consequently, accurate measurement of the urine volume may not be possible. To compensate for this, the collection tube or base / controller may be attached to the bed via an automatic leveling mount, such as a mount on a roller, so that gravity automatically levels the base during installation.

[0343] In some embodiments, slight angles within the system are handled by creating a “rough” surface on the volume of urine in the collection container. The “rough” surface provides multiple angles of ultrasonic reflection, some of which will be approximately 90 degrees from the ultrasonic sensor / transducer. This roughness may be created by vibrating the collection container and / or urine by foaming the urine using air or other gases. Vibration can be achieved by mechanical means, ultrasound, etc. A floating plate may be used that floats on the surface of the urine, having a rough bottom surface and a concave or convex bottom surface. Floating beads that are too large in diameter to escape the container may be provided inside the container to remain in the container when the urine is discharged. A small diameter opening narrowed with a mesh or other mechanism may be used to prevent the beads from entering the overflow area. As mentioned above, urine volume may also be accurately measured using a cassette (or urine collection chamber) having an angled baffle or angled wall or a tapered wall.

[0344] Pressure balloon priming

[0345] Very small amounts of air or fluid may be required to adjust the pressure of a pressure balloon and prime it to optimal pressure sensitivity. For this reason, an air / gas / fluid regulator may be used between the priming fluid and the pressure balloon. This regulator allows the priming pump to operate with less air for more precise pressure balloon priming. This regulator may include foam insertion, fluid lumen narrowing, or any other suitable regulator.

[0346] Regular improvements

[0347] In some embodiments, sensors in the bed, patient, within a sensing Foley catheter system, or elsewhere detect whether the patient is in a supine or non-supine position. Pressure measured in the bladder will increase when the patient is not in a supine position, which may negatively affect the data for analysis by the controller. As a result, the controller may ignore pressure data collected while the patient is not in a supine position, or may stop collecting pressure data during this time. Alternatively, the pressure measurement itself may be used to detect when the patient is not in a supine position. A sudden increase in pressure or an increase above a certain threshold may indicate that the patient has gotten up, moved, or otherwise changed position. Different pressure profiles may indicate different events. Patients who roll to prevent bedsores may be tracked in this manner.

[0348] In some embodiments, EKG measurements, whether obtained through leads attached to a sensing Foley catheter system or independently, are used to synchronize the heart rate measured via the heart rate in the bladder with the EKG.

[0349] In some embodiments, the controller may use the bed angle as an input parameter for calculating IAP or APP, etc. For example, increasing the body angle (raising the patient's head level) would result in an increase in IAP. This increase may differ for healthier patients than for less healthy patients. Consequently, determining IAP at different bed angles may provide additional information about the patient's health. IAP may also be reduced by lowering the head level, which may temporarily stabilize the patient at a high IAP.

[0350] In some embodiments, a sensing Foley catheter may have at least one pressure sensor or lumen in fluid communication with an external pressure sensor. This pressure sensor may rapidly or frequently (ideally above 1 Hz) sense the pressure within the lumen, enabling 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 balloon may be inflated and / or deflated while the pressure applied to the pressure balloon by the body is monitored. The pressure lumen may deliver pressure waves from body cavities, one of which is the pulsation of the heart resulting from the inflow of blood into the lumen organs and / or surrounding tissues. Pulsation pressure from the heart pulsation and / or respiratory deviation can be used to determine pulmonary and cardiovascular pressure. Alternatively, the pressure in the pressure lumen / balloon may be increased above a threshold (i.e., 100 mmHg), and then gradually decreased through the sensing range to determine the origin of the pulse pressure, the point at which the pulse pressure disappears, and / or the relative increase or decrease in the magnitude of the compression pulse. The origin / disappearance or relative increase / phenomenon of the pressure pulsation detected by the pressure sensor can be correlated with blood pressure, perfusion pressure, mean arterial pressure, stroke volume, stroke volume variability, respiratory effort, pulmonary pressure transmission, and other pulmonary, gastrointestinal, renal, or cardiovascular parameters. This process may be similar to that of a blood pressure cuff, in which case the pressure in the cuff is increased above the blood pressure, and then the pressure in the cuff is gradually decreased until a blood pressure waveform (heartbeat) appears or disappears.

[0351] Figure 102 shows the pressure waveform and its collapse during the inflation of a pressure balloon. Note that when the pressure exceeds the mean arterial pressure, the cardiac pulsation decreases and / or disappears. If there is sufficient data to correlate the degree of collapse at a relative pressure point with the mean arterial pressure, the mean arterial pressure can be derived from this relative pressure waveform. The same can be used for lung pressure and other pressures that can be sensed within the body's luminal cavity.

[0352] In some embodiments, the pressure sensor / lumen is a capsule, balloon, or container that can be gradually inflated or filled while monitoring the pressure using an external transducer. In some embodiments, the pressure sensor is associated with a urinary catheter such as a Foley catheter. Alternatively, the pressure sensor may be associated with a nasogastric tube, an oral gastrostomy tube, or a rectal tube. In yet another embodiment, the pressure sensor device and associated pressure-raising device may be fully implantable. In the tissue perfusion embodiment, the pressure sensor may be inflated within the urethra or inflated against the luminal surface, and pulse oximetry may be performed to detect whitening and / or perfusion of the luminal tissue at each pressure to determine the tissue perfusion pressure.

[0353] In some embodiments, the catheter can synergistically use multiple measurement parameters to improve the quality of data analysis. In one embodiment, the catheter has a built-in sensor to acquire an ECG signal, either internally, such as through the urethra or bladder, or externally, such as through a sensor located in the leg or buttocks. Using this signal, other measurement parameters synchronized with the cardiac cycle (e.g., stroke volume) can be synchronized with the electrical signal, and noise can be removed by taking an average or median signal from many individual samples. In other embodiments, the respiratory signal is used to guide which cardiac pressure signal should be used for stroke volume variation analysis by waiting for a model waveform to appear before performing the analysis.

[0354] Figure 103 illustrates a method for synchronizing cardiac signals (such as fluctuations in bladder pressure caused by the pulse of the nearby abdominal aorta) to obtain a clean signal for analysis. When the ECG is acquired in sync with other cardiac signals of interest, individual samples can be synchronized, for example, using the R wave of the ECG. In the figure, the R wave of the ECG is used for the sequence and superimposed after the pressure samples of the foot have been acquired. The central signal is then calculated by taking the median of all pressure samples simultaneously during the cardiac cycle. The mean can also be used. In this way, random noise is filtered out because unrelated high values ​​due to noise in one sample are offset by other similarly unrelated low values. As more data points are added, the underlying signal becomes stronger and available for analysis. For example, in the pressure signal shown, the amplitude between signal peaks can be used to derive the relative stroke amount.

[0355] Figure 104 illustrates a method using respiratory pressure signals to inform cardiac pressure signal analysis for determining stroke volume variability (SVV). This method is particularly valuable in patients who are not using inhalers, i.e., patients without inhalers. Conventional stroke volume measurement techniques, such as thermodilution or pulse contour analysis, have limited ability to measure stroke volume variability (variation in stroke volume between inspiration and expiration) because they cannot capture the respiratory cycle. Using intraluminal pressure as described herein, such as a Foley catheter in the bladder, is effective in that it allows simultaneous acquisition of respiratory and cardiac signals (along with slower-moving intra-abdominal pressure). Thus, because this device is suitable for appropriate analysis of specific properties (such as respiratory rate and magnitude), it is possible to clearly select which respiratory cycle to use for stroke volume variability analysis. In the same figure, the sample pressure signal obtained from the bladder is shown. In the upper pressure raw signal, large fluctuations are due to respiration and can be selected for analysis based on, for example, wave width, amplitude, or peak value. Other properties not shown may be used to define a suitable wave, including slope, area under the curve, shape, frequency, pattern, or repeatability. A curve amplitude filter may also be used, in which case curves with amplitudes above a certain value are used, and curves below this value or below other specific values ​​are not used in the SVV calculation. The diagram below shows the same signal after passing through a high-pass filter and a low-pass filter. The high-pass filter leaves the underlying heart signal (dash line), and the low-pass filter leaves the underlying breathing signal (solid line). In this example, the difference in intensity of the heart signal (value between peaks) between the peaks and troughs of the breathing signal can be used to calculate stroke variation.

[0356] Respiratory rate and other parameters may be sensed via a sensing Foley catheter or obtained by any conventional or non-conventional means. Other parameters that may be collected include tidal volume, vital capacity measurement, respiratory flow parameters, data collected via vital capacity measurement, expiratory effort, inspiratory effort, etc. Any of these parameters may be used to help calculate stroke volume variability and / or other cardiac parameters.

[0357] The filter used to determine which pressure peaks are used in the SVV calculation may be based on any of the pressure curve parameters of this disclosure. Alternatively, the SVV calculation itself may be used to determine which pressure curve peaks are used in the calculation. For example, SVV is typically within a range of about 10%. The system of this disclosure may include or exclude pressure curve data based on whether the resulting SVV calculation is within a specific range, such as about 10%.

[0358] SVV calculations may be patient-specific. For example, the pressure curve peak filter may be based on amplitude, but the cutoff amplitude may be patient-specific, or it may be based on the average of that patient's pressure curve or other parameters. Alternatively, the filter may be based on multiple patients, or on multiple patients within a specific category, such as a particular medical condition.

[0359] Signal and / or SVV calculations may also be filtered for patient movements and / or other actions, such as coughing, shifting, sniffing, etc.

[0360] Furthermore, a calculation result of a very low or nonexistent SVV may indicate fluid overload, and appropriate measures may be indicated.

[0361] In some embodiments of the system of this disclosure, the patient may be encouraged to breathe in a specific manner. For example, the system may encourage the patient to breathe more deeply, more slowly, or normally, based on the shape of the pressure curve (peak amplitude, frequency, etc.). The resulting respiratory pressure curve can then be used as a factor in the SVV calculation. This type of encouragement may be performed by the system when the pressure-volume curve is insufficient to provide for the SVV calculation, or for any other reason.

Claims

1. A drainage assembly configured to prevent an increase in negative pressure, A stretch catheter having a first end configured to be inserted into a body cavity, and having at least one opening near or at the first end that is in fluid communication with the catheter lumen, such that the catheter lumen is defined through fluid communication, A drainage tube having a drainage lumen that is in fluid communication with the second end of the catheter, A rigid cassette configured to fit into a cassette mount and having fluid communication with the drainage pipe lumen, A drain valve is positioned at the entry point where the drainage pipe lumen connects to the cassette, A ventilation mechanism that is in fluid communication with the drainage pipe lumen, The second valve is disposed within the ventilation mechanism and is configured to maintain a closed position until the first pressure level in the drainage pipe lumen drops to a second pressure level and the second valve moves to an open position. A controller is further configured to communicate with the cassette, pressurize the cassette so that the inflow of fluid into the cassette via the drain valve is automatically stopped, and determine the amount of fluid collected in the cassette. A light emitter that communicates electrically with the controller, wherein the light emitter is positioned close to the wall of the cassette so as to emit light into the cassette through the fluid volume collected in the cassette, An assembly comprising:

2. The assembly according to claim 1, wherein the cassette includes an optically transparent portion, and the light emitter emits light into the cassette through the optically transparent portion.

3. The assembly according to claim 2, wherein the cassette includes a reflector portion disposed on or incorporated into the inner wall portion of the cassette.

4. The assembly according to claim 1, wherein the controller is further configured to analyze light transmitted through the cassette and the fluid volume and to determine from the fluid volume the presence of bacteria as an indication of infection.

5. The assembly according to claim 4, wherein the controller is configured to determine the presence of at least one of red blood cells, plasma, and white blood cells from the light transmitted through the cassette.

6. The assembly according to claim 1, wherein the light emitter is configured to emit ultraviolet light.

7. The assembly according to claim 1, wherein moving the second valve from the closed position to the open position introduces gas from the ventilation mechanism into the drain pipe lumen to clean any obstructions.

8. The assembly according to claim 1, wherein the ventilation mechanism comprises one or more filters in communication with the second valve.

9. The assembly according to claim 1, further comprising a vent that is arranged in fluid communication with the second valve, and the vent mechanism prevents the vent from being wetted by the fluid in the drain pipe lumen.

10. The assembly according to claim 9, wherein the vent is located at the remote end of the vent tube.

11. The assembly according to claim 10, wherein the ventilation tube has a length greater than 2 cm.

12. The assembly according to claim 10, wherein the ventilation tube is bendable or deformable.

13. The assembly according to claim 10, wherein the ventilation tube is in fluid communication with the atmosphere.

14. The assembly according to claim 10, wherein the ventilation tube has a length greater than 4 cm.

15. The assembly according to claim 10, wherein the ventilation tube has a length greater than 10 cm.

16. The assembly according to claim 10, wherein the vent tube has a length that extends from the ventilation mechanism together with the drainage tube lumen.

17. The assembly according to claim 9, wherein the vent can be detachably fixed from the ventilation mechanism.

18. The assembly according to claim 9, wherein the vent is equipped with a filter.

19. The assembly according to claim 9, wherein the second valve is positioned between the opening of the drainage pipe lumen and the vent.

20. The assembly according to claim 1, further comprising a pump configured to apply negative pressure to the drainage pipe lumen.

21. The assembly according to claim 1, wherein the second pressure level is periodically or continuously between approximately -5 mmHg and -30 mmHg.

22. The assembly according to claim 1, wherein the second valve comprises a passive mechanism.

23. The assembly according to claim 1, wherein the cassette defines a meandering flow path within the cassette.

24. The controller is configured to periodically apply negative pressure, as described in claim 1. Ri.

25. The assembly according to claim 24, wherein the controller is configured to apply negative pressure at least every 60 minutes.

26. The assembly according to claim 24, wherein the controller is configured to apply negative pressure at least every 20 minutes.

27. The assembly according to claim 1, further comprising a camera in communication with the controller, wherein the camera can be configured to determine the amount of fluid collected in the cassette.

28. The assembly according to claim 1, further comprising a pressure sensor in communication with the controller, wherein the pressure sensor can be configured to determine the amount of fluid collected in the cassette.

29. The assembly according to claim 1, further comprising an ultrasonic sensor in communication with the controller, wherein the ultrasonic sensor can be configured to determine the amount of fluid collected in the cassette.

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