Intra-abdominal pressure ("IPP") measurement device and system

Abstract

An intra-abdominal pressure ("IPP") measurement device is disclosed herein. In an example, the IPP measurement device includes a transfer set or catheter fluidically coupled to a patient's abdominal cavity and a pressure sensor adapted to contact the transfer set or catheter. The pressure sensor is configured to transmit output data indicative of IPP within the patient's abdominal cavity. The pressure sensor includes a pressure element configured to measure pressure exerted by fluid within the transfer set or catheter. The pressure sensor further includes a pressure amplifier having a first side contacting a portion of the transfer set or catheter and a second side contacting the pressure element. The first side has a greater diameter or surface area than the second side for amplifying a pressure signal of the IPP measurement.

Description

BACKGROUND

[0001] For various reasons, a person's renal system can fail. Kidney failure creates several physiological imbalances. For example, a person with kidney failure can no longer balance water and minerals or excrete the daily metabolic load. In addition, toxic end products of metabolism, such as urea, creatinine, uric acid, etc., can accumulate in the patient's blood and tissues.

[0002] Reduced kidney function, especially kidney failure, is treated by dialysis. Dialysis removes waste, toxins and excess water from the body that would otherwise be removed by normal functioning kidneys. Dialysis treatment to replace kidney function is vital to many people because such treatment is life-saving.

[0003] One type of kidney failure therapy is peritoneal dialysis ("PD"), which infuses a dialysis solution, also referred to as dialysis fluid or PD fluid, into a patient's peritoneal cavity via a catheter. The dialysis fluid contacts the patient's peritoneal membrane within the peritoneal cavity. Waste, toxins and excess fluids pass from the patient's bloodstream through capillaries in the peritoneum into the dialysis fluid due to diffusion and osmosis, i.e., a concentration gradient across a membrane. Osmotic agents in the dialysis fluid provide the concentration gradient. Used or spent dialysis fluid is drained from the patient to remove the waste, toxins and excess fluids from the patient. This cycle is repeated multiple times for the patient.

[0004] There are various types of peritoneal dialysis therapies, including continuous ambulatory peritoneal dialysis ("CAPD"), automated peritoneal dialysis ("APD"), tidal flow dialysis and continuous flow peritoneal dialysis ("CFPD"). CAPD is a manual dialysis treatment. Here, the patient manually connects an implanted catheter to a drain line to enable used or spent dialysis fluid to drain out of the peritoneal cavity. The patient then switches fluid communication so that the patient's catheter communicates with a bag of fresh dialysis fluid to infuse fresh dialysis fluid into the patient via the catheter. The patient disconnects the catheter from the fresh dialysis fluid bag and allows the dialysis fluid to dwell within the peritoneal cavity where waste, toxins and excess fluids are transferred. After the dwell period, the patient repeats the manual dialysis procedure, e.g., four times per day. Manual peritoneal dialysis requires a significant amount of time and effort from the patient and there is room for significant improvement.

[0005] Automated peritoneal dialysis ("APD") is similar to CAPD in that a dialysis treatment includes drain, fill, and dwell cycles. However, the APD machine performs the cycles automatically, typically while the patient is sleeping. The APD machine frees the patient from having to manually perform the treatment cycles and from having to deliver supplies during the day. The APD machine is fluidly connected to an implanted catheter, a source or bag of fresh dialysis fluid, and a fluid drain. The APD machine pumps fresh dialysis fluid from the dialysis fluid source through the catheter and into the patient's peritoneal cavity. The APD machine also allows the dialysis fluid to dwell within the cavity and for the transfer of waste, toxins, and excess water to occur. The source can include multiple liters of dialysis fluid, including several solution bags.

[0006] The APD machine pumps used or spent dialysate from the patient's peritoneal cavity through the catheter and to the drain. As with the manual process, several drain, fill, and dwell cycles occur during the dialysis. A "last fill" can occur at the end of the APD treatment. The fluid of the last fill can remain in the patient's peritoneal cavity until the start of the next treatment, or can be manually emptied at some point during the day.

[0007] Typically, a clinician determines certain parameters that specify how the PD treatment is to be performed. For example, the clinician can specify a fill volume parameter that defines an amount of dialysis fluid to be provided to the patient's peritoneal cavity during the fill phase of the treatment cycle. The clinician can also specify a drain parameter that defines how much used or spent dialysate (and ultrafiltrate) is to be removed during the drain. The clinician can also specify a dwell parameter that defines a duration of time that the dialysis fluid is to remain within the patient's peritoneal cavity. For many treatments, the clinician can also prescribe a concentration of glucose for the dialysis fluid to achieve certain treatment goals.

[0008] While all of the above parameters are important for PD treatment, the fill volume parameter can be critical. If the fill volume parameter is too high, the patient can experience overfilling during treatment, which can result in discomfort. If the fill volume parameter is too low, the PD treatment can not be as effective at clearing accumulated toxins. Currently, many clinicians estimate the fill volume parameter using a measured value of the patient's intra-abdominal pressure ("IPP"), which is a measure of the pressure within the patient's abdomen due to accumulated fluid and waste. Generally, the patient's IPP increases as the volume of fluid increases. The fill volume can be determined as the amount of PD fluid provided to the patient's abdomen that causes the pressure to reach a certain clinically allowed threshold, which is typically between 15 to 20 centimeters ("cm") H2O (0.213 to 0.284 pounds per square inch ("psig")). In some cases, the volume of the patient's abdomen is estimated using the patient's height, age, and gender compared to population averages for similar individuals. The estimated volume can then be adjusted based on the measured IPP for determining the fill volume parameter for PD treatment.

[0009] IPP measurements can not be as accurate for various reasons. Relatively low intra-abdominal pressures make IPP measurements particularly challenging because many pressure sensors provide more accurate measurements above 1.0 psig, which can be greater than some IPP ranges. In some cases, the patient or the measuring equipment can move during the measurement, which can affect the IPP measurement. Even slight movement can cause the IPP measurement to vary by 20% to 30%. In addition, the patient's food and beverage consumption in the twenty-four hours prior to the measurement can affect the IPP measurement.

[0010] Accordingly, there is a need for improved IPP measurement systems and methods. SUMMARY

[0011] Example systems, methods, and apparatuses for improved intra-abdominal pressure ("IPP") measurement or estimation are disclosed herein. In some embodiments, these systems, methods, and apparatuses include a pressure amplifier provided with a pressure sensor that is connected to or otherwise integrally integrated with a transfer set or catheter. An example pressure amplifier includes a first side that contacts the transfer set or catheter and a second side that contacts a pressure sensor element. The first side has a smaller diameter than the second side. The pressure exerted by PD fluid located within the transfer set or catheter on the first side of the amplifier increases in amount based on Pascal's law to exert a proportionally greater force on the pressure sensor element. In alternative embodiments, pressure amplification can be accomplished using a different material having greater elasticity than the rest of the transfer set or catheter. The area having greater elasticity exerts a proportionally greater pressure on the sensor element. Improved pressure measurement enables the clinician to determine a fill volume parameter that is appropriate for the patient.

[0012] Additionally or alternatively, in some embodiments, the systems, methods, and apparatuses disclosed herein include a force sensor disposed within a pressure sensor housing for measuring IPP. The force sensor can include at least one of an inertial sensor, a gyroscope, and / or an accelerometer for sensing at least one of linear and / or rotational acceleration in one or more axes. The force sensor provides an indication of patient movement and / or pressure sensor movement during IPP measurement. Data output from the force sensor is used to normalize or adjust IPP measurement data to compensate for any detected patient movement and / or pressure sensor movement that would otherwise affect the IPP measurement.

[0013] Additionally or alternatively, in some embodiments, the systems, methods, and apparatuses disclosed herein include a spirometer for IPP pressure measurement. As additional volumes of PD fluid are delivered to the patient's abdominal cavity, the spirometer records the patient's vital capacity. The correlation between the patient's vital capacity and IPP at different fill volumes enables the clinician to use the measured vital capacity to determine a fill volume parameter. In some cases, the spirometer is used with the pressure sensor to provide a more accurate estimation of IPP and / or fill volume parameter. In other cases, the spirometer is used in place of the pressure sensor to estimate the patient's IPP for determining a fill volume parameter for PD therapy.

[0014] Additionally or alternatively, in some embodiments, the systems, methods, and apparatuses disclosed herein include a processor that performs a comparison of IPP measurements to one or more ranges of pressure data to determine whether a drain and / or transfer set is partially occluded or mispositioned. The detected pressure is compared to the one or more ranges during filling of the patient's abdominal cavity with PD fluid. IPP data detected within a certain range can result in an alert being provided to prompt a clinician to check the drain or transfer set. In some cases, IPP measurement data is not accepted until it falls within an acceptable range during PD fluid filling. Further, the processor can be configured to compare measured IPP data to one or more acceptable ranges to confirm that the IPP measurement corresponds to a dwell rather than a PD fluid fill.

[0015] Additionally or alternatively, in some embodiments, the systems, methods, and apparatuses disclosed herein include a processor that receives patient information indicative of urine output, food / beverage intake, heart rate, and / or blood pressure of the patient. The patient information can correspond to a time period before, during, and / or after an IPP measurement. The processor is configured to use the patient information to adjust a fill volume parameter such that the parameter is not based solely on the IPP measurement. The patient information includes factors that can affect the IPP measurement. For example, a high degree of beverage consumption and low urine output can indicate that the patient is bloated or retaining water, which can result in a larger IPP measurement than a patient with a more normal fluid balance. Accounting for these factors can allow for a more accurate fill volume to be determined for the patient.

[0016] In accordance with the disclosure set forth herein, and without limiting the disclosure in any way, in a first aspect of the disclosure (which can be combined with any other aspect or portion thereof described herein), an intra-abdominal pressure ("IPP") measurement apparatus includes a transfer set or drain fluidly coupled to an abdominal cavity of a patient, and a pressure sensor configured to contact the transfer set or drain. The pressure sensor is configured to transmit output data indicative of an IPP within the abdominal cavity of the patient. The pressure sensor includes a pressure element configured to measure a pressure exerted by a fluid within the transfer set or drain, and a pressure amplifier having a first side and a second side, the first side contacting a portion of the transfer set or drain, the second side contacting the pressure element. The first side has a greater diameter or surface area than the second side.

[0017] In a second aspect of the disclosure (which can be combined with any other aspect or portion thereof described herein), the first side includes a diameter or surface area that is at least twice the diameter or surface area of the second side to provide at least a 2x pressure amplification.

[0018] In a third aspect of the disclosure, which can be combined with any other aspect or portion thereof described herein, the pressure element includes at least one of a piezoresistive strain gauge, a pressure sensing diaphragm, a capacitive diaphragm, a pressure sensing capsule, or a Bourdon tube.

[0019] In a fourth aspect of the disclosure, which can be combined with any other aspect or portion thereof described herein, the pressure sensor is integrally formed with the transfer set or the drainage tube.

[0020] In a fifth aspect of the disclosure, which can be combined with any other aspect or portion thereof described herein, the pressure sensor is mechanically connected to the transfer set or the drainage tube.

[0021] In a sixth aspect of the disclosure, which can be combined with any other aspect or portion thereof described herein, an intra-abdominal pressure (“IPP”) measurement system includes a fluid container containing an abdominal dialysis (“PD”) fluid, and a transfer set and a drainage tube in fluid communication with the fluid container and configured to be in fluid communication with an abdominal cavity of a patient to enable the PD fluid to be provided to the abdominal cavity of the patient. The system further includes a pressure sensor configured to contact the transfer set or the drainage tube. The pressure sensor is configured to transmit output data indicative of an IPP within the abdominal cavity of the patient. The pressure sensor includes a pressure element configured to measure a pressure exerted by the fluid within the transfer set or the drainage tube, and a pressure amplifier having a first side contacting a portion of the transfer set or the drainage tube and a second side contacting the pressure element. The first side has a greater diameter or surface area than the second side. The system further includes a processor communicatively coupled to the pressure sensor. The processor is configured to: receive the output data indicative of the IPP within the abdominal cavity of the patient; and at least one of determine a fill volume parameter for a PD treatment of the patient using the output data indicative of the IPP or cause display of the output data indicative of the IPP to enable determination of the fill volume parameter.

[0022] In a seventh aspect of the disclosure, which can be combined with any other aspect or portion thereof described herein, the output data indicative of the IPP within the abdominal cavity of the patient corresponds to a pressure measurement taken by the pressure sensor during a dwell interval between providing the PD fluid to the abdominal cavity of the patient and clearing the PD fluid from the abdominal cavity of the patient.

[0023] In an eighth aspect of the disclosure, which can be combined with any other aspect or portion thereof described herein, the fluid container is placed at the head height, and the system further comprises a line clamp that, when closed, blocks the flow of PD fluid through the transfer set or the drain tube.

[0024] In a ninth aspect of the disclosure, which can be combined with any other aspect or portion thereof described herein, the system further comprises a pump configured to move the PD fluid from the fluid container through the transfer set and the drain tube to the patient's peritoneal cavity when activated.

[0025] In a tenth aspect of the disclosure, which can be combined with any other aspect or portion thereof described herein, the system further comprises an automated peritoneal dialysis ("APD") machine configured to provide a PD treatment for the patient using at least the fill volume parameter.

[0026] In an eleventh aspect of the disclosure, which can be combined with any other aspect or portion thereof described herein, the system further comprises a force sensor included on the pressure sensor or adapted to contact the transfer set or the drain tube. The force sensor comprises at least one of an inertial sensor, a gyroscope, or an accelerometer for sensing at least one of linear or rotational acceleration in one or more axes. The force sensor is configured to output force data indicative of at least one of patient movement or pressure sensor movement.

[0027] In a twelfth aspect of the disclosure, which can be combined with any other aspect or portion thereof described herein, the processor is configured to receive the force data and use the force data to adjust the output data indicative of the IPP to account for a measurement component related to at least one of patient movement or pressure sensor movement.

[0028] In a thirteenth aspect of the disclosure, which can be combined with any other aspect or portion thereof described herein, the processor is configured to: compare the output data indicative of the IPP to at least one data range; provide an indication that at least one of the transfer set or the drain tube is problematic when the comparison is outside the at least one data range; and use the output data indicative of the IPP to determine the fill volume parameter when the comparison is within the at least one data range.

[0029] In a fourteenth aspect of the present disclosure, which can be combined with any other aspect or portion thereof described herein, the processor is configured to: receive second output data from the pressure sensor, the second output data indicative of pressure during filling of the patient's abdominal cavity with an increased amount of PD fluid; compare the second output data indicative of pressure during filling of the patient's abdominal cavity to a second data range; provide an indication that at least one of the transfer set or the drain is problematic when the comparison is outside the second data range; and use the output data indicative of IPP to determine the fill volume parameter when the comparison is within the second data range.

[0030] In a fifteenth aspect of the present disclosure, which can be combined with any other aspect or portion thereof described herein, the processor is configured to: receive patient information, the patient information including at least one of urine output over a defined time period, food / beverage intake over a defined time period, heart rate, or blood pressure; and use the patient information to adjust the output data indicative of IPP or the fill volume parameter.

[0031] In a sixteenth aspect of the present disclosure, which can be combined with any other aspect or portion thereof described herein, the defined time period includes at least one of twenty-four hours or forty-eight hours prior to causing the pressure sensor to provide output data indicative of IPP of the patient.

[0032] In a seventeenth aspect of the present disclosure, which can be combined with any other aspect or portion thereof described herein, an intra-abdominal pressure ("IPP") measurement system includes a fluid container containing peritoneal dialysis ("PD") fluid, and a transfer set and a drain fluidly coupled to the fluid container and to an abdominal cavity of a patient to enable the PD fluid to be provided to the abdominal cavity of the patient. The system further includes a spirometer for transmitting output data indicative of a lung capacity of the patient, and a processor communicatively coupled to the spirometer. The processor is configured to: record the output data from the spirometer during a dwell interval between providing the PD fluid to the abdominal cavity of the patient and removing the PD fluid from the abdominal cavity of the patient; and determine at least one of IPP or a fill volume parameter based at least on the output data from the spirometer using a correlation between the lung capacity and the IPP.

[0033] In an eighteenth aspect of the present disclosure, which can be combined with any other aspect or portion thereof described herein, the system further includes a pressure sensor adapted to contact the transfer set or the drain. The pressure sensor is configured to transmit second output data indicative of IPP within the abdominal cavity of the patient, wherein the processor is configured to determine the fill volume parameter using the output data from the spirometer and the second output data from the pressure sensor.

[0034] In a nineteenth aspect of the present disclosure, which can be combined with any other aspect or portion thereof described herein, the fluid container is placed at the head height, and the system further comprises a line clamp that, when closed, blocks the flow of PD fluid through the transfer set or the drain tube.

[0035] In a twentieth aspect of the present disclosure, which can be combined with any other aspect or portion thereof described herein, the system further comprises a pump configured to move the PD fluid from the fluid container through the transfer set and the drain tube to the patient's abdominal cavity.

[0036] In a twenty-first aspect, any of the features, functions, and alternatives described in relation to any one or more of Figures 2-15 may be combined with any of the features, functions, and alternatives described in relation to any other figure. Figures 2-15

[0037] In view of the present disclosure and the above aspects, it is therefore an advantage of the present disclosure to provide improved IPP measurement or estimation.

[0038] Another advantage of the present disclosure is to determine a more accurate fill volume parameter for PD treatment.

[0039] Yet another advantage of the present disclosure is to consider patient factors and / or movement during IPP measurement to provide adjustments to IPP measurement.

[0040] Additional features and advantages are described in, and will be apparent from, the following DETAILED DESCRIPTION and the Figures. The features and advantages described herein are not all-inclusive and, in particular, many additional features and advantages will be readily apparent to one of ordinary skill in the art in view of the Figures and the Description. Also, any particular embodiment does not necessarily have all of the enumerated advantages, and explicit reference to individual advantageous embodiments is not necessarily required to claim each of the advantageous embodiments. Moreover, it should be noted that the language used in the specification is principally intended to be read in light of the drawings and the specification, and not for limiting the scope of the inventive subject matter. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 A schematic diagram showing known IPP measurement techniques is shown.

[0042] Figure 2 A schematic diagram showing how the volume of the abdominal cavity changes during inspiration and expiration of respiration is shown.

[0043] Figure 3 And Figure 4 are schematic diagrams of example IPP measurement systems according to example embodiments of the present disclosure. ​

[0044] Figures 5-7 is a schematic diagram of a pressure sensor according to example embodiments of the present disclosure. Figure 3 and Figure 4 is a schematic diagram of a pressure sensor according to example embodiments of the present disclosure.

[0045] Figure 8 is a schematic diagram of a force sensor connected to or otherwise integrated with a pressure sensor according to example embodiments of the present disclosure. Figures 3-7

[0046] Figure 9 is a flowchart schematic of an example procedure for using force output data in conjunction with IPP measurements to determine a fill volume parameter according to example embodiments of the present disclosure.

[0047] Figure 10 is a schematic diagram illustrating how a processor and / or a portable device calculates an IPP component related to patient movement and / or sensor movement according to example embodiments of the present disclosure.

[0048] Figure 11 and Figure 12 is a schematic diagram of a plot illustrating comparison of IPP measurements to one or more ranges and / or thresholds according to example embodiments of the present disclosure.

[0049] Figure 13 is a schematic diagram illustrating data processing by a processor and / or a portable device to adjust IPP measurements based on patient information according to example embodiments of the present disclosure.

[0050] Figure 14 is a schematic diagram of an example system in which spirometry is used to determine a fill volume parameter for PD treatment according to example embodiments of the present disclosure.

[0051] Figure 15 is a schematic diagram of a plot of patient-specific correlation between spirometry and fill volume according to example embodiments of the present disclosure. DETAILED DESCRIPTION

[0052] ​Disclosed herein are methods, systems, and devices for improved intra-abdominal pressure (IPP) measurement or estimation. These methods, systems, and devices provide more accurate IPP measurement and / or fill volume estimation compared to known IPP measurement techniques. As described herein, these methods, systems, and devices include one or more of: (i) providing a sensor amplifier to amplify the measurements of a pressure sensor to coincide with a more sensitive and accurate region of the pressure sensor element; (ii) using a force sensor to adjust for movement of the pressure sensor and / or patient during IPP measurement; (iii) using a spirometer to correlate vital capacity with IPP and / or patient fill volume; (iv) using a known range to validate IPP measurement data, and / or (v) using urine output data, food / beverage consumption data, blood pressure data, and / or heart rate data to adjust IPP measurement and / or fill volume estimation.

[0053] The disclosure herein is directed to performing IPP measurement to determine fill volume parameters for PD therapy. It should be appreciated that any of the methods, systems, and devices disclosed herein can also be used to measure IPP during PD therapy. IPP measurement during therapy can be used to stop PD fluid fill when the detected IPP exceeds a threshold, extend PD drain, and / or change from continuous cycling peritoneal dialysis (“CCPD”) therapy to tidal flow therapy when the residual volume within the patient’s abdomen exceeds a threshold. In some cases, IPP measurement values that exceed a threshold can trigger an alarm to the patient and / or alert a clinician.

[0054] Figure 1 A schematic diagram of a known IPP measurement technique is shown. The known IPP measurement system 100 includes a transfer set 102 fluidly connected to a drain tube 104 that is inserted into or fluidly connected to a patient’s abdomen 106. The other end of the transfer set 102 (not shown) is connected to a source or container of fluid, such as PD fluid. The IPP measurement system 100 also includes a measurement or drain line 108 that is fluidly connected to the drain tube 104 and / or the transfer set 102.

[0055] IPP measurement provides a measurement of IPP within a patient’s abdomen for a volume of infused PD fluid. For IPP measurement, the patient is typically in a supine or horizontal position, as shown. Figure 1 Moreover, the patient is relaxed, and their head is supported to enable their abdominal wall to relax. This patient position avoids pressure on the abdomen. As shown, Figure 1 A drain bag 112 is held on an elevated stand for the drain line 108. A scale or other distance measuring device 114 is placed alongside the drain line 108, extending from the patient up to the bag 112, and aligning the 0 level (i.e., 0 cm) with the midaxillary line, as shown.

[0056] To perform the measurement, PD fluid is provided from the source through the transfer set 102 and the drain tube 104 to the patient's abdominal cavity 106. The abdominal cavity 106 is filled to a certain percentage of the cavity volume. After the desired amount of PD fluid has been provided to the abdominal cavity 106, the clamp 110 is closed to prevent further flow of fluid from the source. Next, the drain tube connection is opened to allow at least some of the PD fluid to flow from the patient's abdominal cavity into the drain line 108. The column of PD fluid rises in the drain line 108 to a level at which the column stabilizes with respiratory oscillations of 1 to 3 cm of H20, which provides an average measurement. Figure 2 is a schematic showing how the abdominal cavity volume changes during inspiration and expiration of respiration. As shown in this figure, the IPP is larger during inspiration because the abdominal cavity contracts to become smaller. The IPP change delta between inspiration and expiration is averaged to determine the IPP of the patient. In other words, the IPP is measured as the midpoint of this oscillation and expressed in centimeters ("cm") of H20. Once the measurement is obtained, the abdominal cavity is drained and the volume in the drain bag 112 is recorded as the fill volume. This process can be repeated for different amounts of PD fluid to determine the correlation between the IPP measurement and the fill volume for a particular patient.

[0057] In stable adult PD patients, an IPP of 10 to 16 cm of H20 over the midaxillary line is considered acceptable for PD treatment, which typically corresponds to 1.3 to 2.8 liters ("L") of infused PD fluid. The difference between IPP and infused PD fluid volume among patients is attributed to changes in abdominal cavity volume ("IPV"), body position (patients who are standing show an increase of 2 to 4 cm of H20 compared to lying down), physical activity, body weight, height, and gender. Clinicians typically aim to keep the IPP below 18 to 20 cm of H20 because higher pressures are associated with symptoms such as discomfort, bloating, sleep disturbances, hemodynamic problems, and respiratory changes. Higher pressures can also lead to certain mechanical complications (leakage, hernias, etc.).

[0058] IPP measurements can also be performed while the patient is standing or sitting. In these cases, the "0" point is considered to be over the midaxillary line, i.e., at the midpoint between the xiphoid process and the pubic symphysis, or in the patient's anterior superior iliac spine. The IPP measurement is performed in the same manner as described above for a patient who is lying down, despite the change in position.

[0059] I. IPP measurement embodiment

[0060] Figure 3 and Figure 4is a schematic diagram of an example IPP measurement system 300 according to example embodiments of the present disclosure. The example system 300 includes a transfer set 102 having a first end connected to a fluid container 302. The fluid container 302 can include any physiologically compatible fluid source. The fluid container 302 is a PD fluid source and can include a bag or other housing configured to hold a volume of fluid, such as one to two liters of fluid. In some embodiments, the fluid container 302 includes fresh, pre-made PD fluid having a certain prescribed glucose concentration. In some embodiments, the fluid container 302 can include two chambers, one having dialysis concentrate and the other having purified water. In such embodiments, the container 302 includes a seal that, when broken, enables the fluids in the two chambers to mix. Physiologically compatible fluids can include PD fluid, normal saline, renal replacement fluid, etc.

[0061] A second end of the transfer set 102 is connected to a drain tube 104 fluidically coupled to a patient's peritoneal cavity 106. The transfer set 102 and / or the drain tube 104 can be made of any one or more of the following: polyvinyl chloride ("PVC"), polyethylene ("PE"), polyurethane ("PU"), polycarbonate, or other non-PVC materials.

[0062] In some embodiments, Figure 3 The system 300 can include a line clamp 110 to selectively restrict the flow of PD fluid through the transfer set 102. The illustrated embodiment can also include a pump 304. The example pump 304 can include a pump head fluidically connected to the transfer set 102. The pump 306 can be any type of fluid pump, such as a peristaltic pump, a gear pump, or a membrane pump. The pump head can be disposable and connected to a reusable actuator that is controlled by an internal or external control unit. The example pump 304 is configured to pump fresh PD fluid from the container 302 to the patient's peritoneal cavity 106 to perform an IPP measurement. The example pump 304 can also pump used PD fluid (including cleared toxins and absorbed ultrafiltrate) from the patient's peritoneal cavity 106 back to the container 302 after the IPP measurement has been recorded. In alternative embodiments, separate pumps are provided for (i) pumping fluid to the patient and (ii) pumping or pulling fluid from the patient. In some embodiments, the pump 304 is configured to block fluid flow from the fluid container 302 until the pump head is actuated, thereby preventing free flow of PD fluid and enabling the clamp 110 to be omitted.

[0063] Figure 3The IPP measurement system 300 also includes a pressure sensor 306 for performing IPP measurements. The pressure sensor 306 in the illustrated embodiment is positioned to measure the fluid pressure within the transfer set 102. In other embodiments, the pressure sensor 306 can be connected to or provided with the drain tube 104. When PD fluid is being provided to or cleared from the abdominal cavity 106, the pressure measurements are indicative of the fluid pressure being delivered to or cleared from the abdominal cavity 106. When pumping is stopped and the PD fluid is allowed to dwell within the abdominal cavity for a particular duration, the pressure measurements provided by the pressure sensor 306 are indicative of the IPP. The pressure measurements can also be used to detect tubing occlusions (based on positive pressure or negative pressure spikes / trends going upward) or fluid leaks (based on positive pressure or negative pressure spikes / trends going downward).

[0064] In the illustrated example, the pressure sensor 306 is shown in-line with the transfer set 102. It should be appreciated that the pressure sensor 306 can be in-line with or otherwise integrated with the drain tube 104. It should also be appreciated that the pressure sensor 306 can include a disposable tubing segment that contacts the transfer set 102 and the PD fluid, while the remainder of the sensor 306 can be reusable between IPP measurements. Alternatively, the entire pressure sensor 306 can be disposable.

[0065] In some embodiments, the system 300 can also include a flow sensor (not shown) with an output that is integrated to measure the volume of PD fluid provided to and / or cleared from the patient. It should be appreciated that, in addition or alternatively, one or more pressure sensors 306 can be used to measure the flow or flow rate of fluid delivered to or cleared from the abdominal cavity 106. Further, the system 300 can include a heater for heating the PD fluid prior to infusion to the patient. The system 300 can further include a temperature sensor to ensure that the PD fluid is heated to a desired temperature.

[0066] Although not shown, an air trap can be provided in the transfer set 102 to clear air from the PD fluid prior to delivery to the patient. In other cases, priming of the transfer set 102 can clear the air without the need for an air trap. Heating of the dialysis fluid tends to cause dissolved air to separate from the dialysis fluid. Thus, it is contemplated that the air trap be positioned downstream of the heater (e.g., along the transfer set 102) and upstream of the temperature sensor.

[0067] The example system 300 also includes a processor 310 for communicating with the pressure sensor 306. The processor 310 can include any computer, notebook, workstation, server, etc. In some embodiments, the processor 310 is communicatively coupled to the pressure sensor 306 via a wired interface, such as a universal serial bus (“USB”) connection, or a wireless interface, such as a Bluetooth® connection, ZigBee® connection, or near field communication (“NFC”) connection. Additionally, the processor 310 can also be communicatively coupled to the pump 304.

[0068] As described herein, the example processor 310 executes machine-readable instructions stored in a memory device. The instructions can include an application or software program. Execution of the instructions causes the processor 310 to perform the operations described herein. For example, the processor 310 receives IPP measurement output data transmitted from the pressure sensor 306. The processor 310 can ensure that the received IPP output data is within a specified range. Additionally, the processor 310 can adjust the output data based on patient information and / or force sensor information.

[0069] The operations performed by the processor 310 provide for determination of a fill volume parameter for PD therapy. In some embodiments, the processor 310 uses the received data to calculate or otherwise determine a fill volume parameter for the patient being measured. Additionally or alternatively, the processor 310 can cause a display device to display the IPP measurement and / or adjustment information to enable a clinician to determine a fill volume parameter for PD therapy for the patient.

[0070] Figure 4 is a schematic illustration of another embodiment of an IPP measurement system 300. In the illustrated example, the pump 304 is replaced by positioning the fluid container 302 at or above the patient’s head height (e.g., three to six feet above the ground level). This enables gravity to pull the PD fluid from the fluid container 302 through the transfer set 102 to the patient’s abdominal cavity 106. In the illustrated example, the clamp 110 provides selective flow of the PD fluid. Figure 4

[0071] Additionally, the processor 310 can be communicatively coupled to the pump 304 via a wired interface, such as a USB connection, or a wireless interface, such as a Bluetooth® connection, ZigBee® connection, or NFC connection. In some embodiments, the processor 310 is communicatively coupled to the pump 304 via a wired interface, such as a USB connection, or a wireless interface, such as a Bluetooth® connection, ZigBee® connection, or NFC connection. Figure 4 The portable device 402 is shown communicatively coupled to the pressure sensor 306. This connection can be via a wired interface, such as a USB connection, or a wireless interface, such as a Bluetooth® connection, ZigBee® connection, or NFC, etc. The portable device 402 can include a smartphone, tablet, laptop, etc. In some cases, the portable device 402 is communicatively coupled to a server or cloud via an internet or local area connection, such as Wi-Fi. The portable device 402 is shown communicatively coupled to the pressure sensor 306. This connection can be via a wired interface, such as a USB connection, or a wireless interface, such as a Bluetooth® connection, ZigBee® connection, or NFC, etc. The portable device 402 can include a smartphone, tablet, laptop, etc. In some cases, the portable device 402 is communicatively coupled to a server or cloud via an internet or local area connection, such as Wi-Fi. Figure 3 ​​The processor 310. The portable device 402 is configured to receive IPP output data from the pressure sensor 306 for determining the patient's filling volume parameters. Figure 3 Similar to the processor 310, the portable device 402 is capable of adjusting IPP measurements and / or filling volume parameters based on force sensor output data and / or patient information.

[0072] Figures 5-7 This is an example embodiment based on the present disclosure. Figure 3 and Figure 4 A schematic diagram of pressure sensor 306 is shown. In the illustrated embodiment, the pressure sensor includes an amplifier. Typical IPP values ​​are between 15 and 20 cm⁻¹ H₂O (0.213 to 0.284 psig). However, many commercial pressure sensors used in medical applications have a pressure range of 0.0 to 5.0 psig. Therefore, using a commercial pressure sensor to measure IPP may only utilize a small fraction of the lower side of the detectable pressure. Many known pressure sensors have low accuracy below 0.8 psig and may not have sufficient measurement accuracy for the pressure range between 0.2 and 0.3 psig. The disclosed amplifier increases the measurement range, thereby enabling pressure sensor 306 to provide a more accurate distinction between IPP measurements.

[0073] Figure 5 A pressure sensor 306 is shown, which is adapted to contact the transfer kit 102. In other cases, the pressure sensor 306 may be connected to or integrated with the flow guide 104. The pressure sensor 306 includes a pressure element 502 that converts the measured pressure into a digital and / or analog signal. The pressure element 502 includes at least one of a piezoresistive strain gauge, a pressure-sensing diaphragm, a pressure chamber, a capacitive diaphragm, a pressure-sensing capsule, or a Boulden tube.

[0074] The pressure sensor 306 also includes an amplifier 504. The amplifier 504 includes a first side that is a portion of the contact transfer assembly 102. A second, opposing side of the amplifier 504 contacts the pressure element 502. Compared to the second side of the pressure element 502, the first side of the amplifier 504 has a larger diameter or surface area. The difference in force... Figure 5 The image shows pistons, with the first piston having a larger surface area than the second piston. A force applied to the first piston from the transfer assembly 502 causes the first piston to exert a force on the second piston. The force from the first piston concentrates on the smaller surface area of ​​the second piston. This concentration of force results in an increase in the applied force, which is sensed by the pressure element 502.

[0075] In one embodiment, the pressure amplifier 504 uses Pascal's Law to amplify the fluid pressure in the transfer set 102. Pressure amplification enables medical grade pressure sensors to be used for such low IPP measurement applications. According to Pascal's Law, force or pressure is proportional to the surface area over which the force is applied. In an example, a force of 1 psig applied to a first surface area of 2 cm 2 results in a force of approximately 2 psig on a second surface area of 1 cm 2 that is pneumatically and / or mechanically coupled. In the illustrated example, the area of the first side (Al) of the amplifier 504 is at least twice the area of the second side (A2), thereby providing an amplification factor of at least two. In other embodiments, the areas of the first and second sides can be selected to provide amplification factors of three, four, five, ten, twenty, etc.

[0076] In the illustrated example, the processor 310 and / or the portable device 402 are configured to normalize the IPP measurement to account for the amplification. For example, if amplification is provided by the amplifier 504, the processor 310 and / or the portable device 402 can reduce the IPP measurement value by the amplification factor. In other embodiments, the fill volume parameter can be related to the amplified IPP measurement value.

[0077] Figure 6 An alternative embodiment of the pressure sensor 306 is shown. In the illustrated embodiment, a section 602 of the transfer set 102 includes a material that has greater elasticity than the other sections. The greater elasticity enables the section 602 to amplify the pressure applied to the pressure element 502 as the pressure within the transfer set 102 increases. Similar to the examples discussed in connection with Figure 5 the first and second surfaces, Figure 6 the example provides an increased IPP measurement range, thereby improving the accuracy of IPP measurement detection. In some embodiments, the elasticity of the material of the section 602 is linear. If the material of the section 602 exhibits non-linear expansion, the processor 310 and / or the portable device 402 are configured to account for the non-linearity of the material. Such accounting can include providing the section 602 with a non-linear calibration curve that corresponds to linear pressure changes within the transfer set 102.

[0078] Figure 7Another embodiment of a pressure sensor 306 is shown. In this example, at least a portion of the transfer set 102 includes a dual lumen with a fluid path side 702 and a non-fluid path side 704. This dual lumen can extend through the transfer set 102, or be located at a section adjacent to the sensor element. The non-fluid path side 704 can be filled with air or fluid of a known volume and / or pressure, providing a reference pressure. A diaphragm 706 separates the two sides 702 and 704 of the transfer set 102. When the reference side 704 has a greater pressure, the diaphragm 706 moves toward the fluid path side 702, and vice versa. A sensor element 710 can be positioned adjacent to the reference side 704. As the diaphragm 706 moves, the volume within that side 704 changes, changing the internal pressure. The sensor element 710 senses this internal pressure, which is transmitted to the processor 310 and / or the portable device 402 as an IPP measurement.

[0079] II. Force sensing embodiment

[0080] Figure 8 is a schematic diagram showing a force sensor 802 connected to or otherwise integrated with a pressure sensor 306 according to example embodiments of the present disclosure. Figures 3-7 In some cases, IPP measurements performed by the pressure sensor 306 can be inaccurate due to changes in the orientation of the patient or the sensor itself. Changes in orientation or position result in an increase or decrease in IPP pressure readings due to changes in head height and / or changes in stress on the abdominal cavity.

[0081] To reduce IPP measurement errors, example force sensors 802 provide force output data indicating movement of the pressure sensor 306 and / or movement of the patient. This force output data is received by the processor 310 and / or the portable device 402 to adjust IPP measurements and / or fill volume parameters. In some cases, force values above a certain threshold can cause the processor 310 and / or the portable device 402 to ignore IPP measurements. For example, detecting a significant change in patient position can cause IPP measurements recorded during that movement to be cleared from the processor 310 and / or the portable device 402, as that movement can contribute significant error to the measurements.

[0082] Force sensor 802 may include an inertial sensor, a gyroscope, and / or an accelerometer. Sensing may be provided on at least one axis, including the x-axis, y-axis, z-axis, yaw axis, pitch axis, and / or roll axis. In some embodiments, force sensor 802 and / or pressure sensor 306 are positioned on or in line with the patient's midline (if supine) or pelvic cup (if sitting / standing). Force sensor 802 detects relative changes in the orientation / angle of pressure sensor 306 and / or the patient relative to the initial placement position.

[0083] Force sensor 802 transmits force output data to processor 310 and / or portable device 402. In some cases, force sensor 802 may use the same transceiver or transmitter as pressure sensor 306. In other cases, force sensor 802 may have its own transceiver or transmitter. Processor 310 and / or portable device 402 use the force output data to determine whether the IPP measurement should be processed, and if so, to provide adjustments to the IPP measurement and / or fill volume parameters.

[0084] Figure 9 This is a flowchart of an example procedure 900 for combining force output data with IPP measurements to determine a patient's filling volume parameters, according to an exemplary embodiment of this disclosure. Although referenced... Figure 9 The flowchart shown describes procedure 900, but it should be understood that many other methods can be used to perform the steps associated with procedure 900. For example, the order of the blocks can be changed, some blocks can be combined with other blocks, and the blocks described can be optional. In one embodiment, the number of blocks can be varied. For example, force output data can be used to correct for fill volume parameters instead of IPP measurements. The actions described in procedure 900 are specified by one or more instructions and can be performed among multiple devices, including, for example, force sensor 802, pressure sensor 306, processor 310, and / or portable device 402.

[0085] Example procedure 900 begins when the patient is connected to transfer kit 102 and drainage tube 104. After transfer kit 102 is in place, force sensor 802 is zeroed or reset (box 902) while positioned at the patient's midline or low pelvis. This reset provides the zero point for the inertial sensor and / or accelerometer. In some cases, the clinician can manually zero force sensor 802 by pressing a reset button on the sensor. Alternatively, the clinician can type input into processor 310 and / or portable device 402, which transmits instructions to force sensor 802 to zero or reset it.

[0086] The clinician then begins filling the patient's abdominal cavity. After the abdominal cavity is filled to a certain percentage, the flow of PD fluid is stopped, and pressure sensor 306 transmits IPP measurement data 903, which indicates the IPP within the abdominal cavity (box 904). Processor 310 and / or portable device 402 receive force output data 905 from force sensor 802 (box 906). Processor 310 and / or portable device 402 compares the force output data 905 to one or more force limits (box 908). If the force output data 905 exceeds the one or more force limits, processor 310 and / or portable device 402 ignores the corresponding IPP measurement data 903 (box 910). Force output data exceeding the one or more limits may indicate that the patient has changed position, made more significant movements, or that pressure sensor 306 or transfer tubing 102 has fallen out. In these cases, the IPP measurement data will be inaccurate or not represent the actual IPP pressure.

[0087] When the force output data is within one or more of the stated limits, the processor 310 and / or the portable device 402 continue to process the IPP measurement data 903 (block 912). This includes determining the IPP measurement component resulting from the measured force (block 914). Figure 10 This is a schematic diagram illustrating how the processor 310 and / or portable device 402, according to an exemplary embodiment of this disclosure, calculates the IPP component associated with patient movement and / or sensor movement. In the illustrated example, sensors 306, 802 can be moved to different or more convenient positions for the clinician or patient, such as higher or lower. This could be due to a higher patient drainage tube outlet or to position sensors 306, 802 in the most comfortable or convenient position for the clinician / patient. The processor 310 and / or portable device 402 uses raw force output data 1002 to calculate the positional change of sensors 306, 802. This positional change provides, for example, a change in head height, which, based on the degree of the change, is associated with a change in pressure within the transfer kit 102. Changes in lateral position and / or rotation also correspond to changes in pressure. This pressure change is summarized as the IPP component (i.e., Δh) associated with the movement of sensors 306, 802 and / or the patient. Figure 10 As shown, processor 310 and / or portable device 402 adjust the IPP measurement based on the IPP components associated with the force output data. This may include updating adjustments based on the IPP components or performing subtraction. Figure 9 (Box 916).

[0088] Back Figure 9The processor 310 and / or the portable device 402 then outputs or otherwise causes display of the adjusted IPP measurement 917 (block 918). In some cases, the steps of blocks 902-918 are repeated at least once to obtain a sample set of IPP measurements for one or more respiratory cycles to enable averaging of the IPP measurements. In some embodiments, the processor 310 and / or the portable device 402 causes display of a graph showing IPP measurements over time, enabling calculation or other determination of an average. The processor 310 and / or the portable device 402 next determines a fill volume parameter based on the adjusted IPP measurement (block 920). The fill volume can be determined by correlating the IPP measurement to fill volumes of patients having similar body mass / height to the patient being measured. In other cases, the volume of PD fluid infused to the patient can be measured using a flow sensor or drain and measuring the PD fluid.

[0089] In some embodiments, additional PD fluid can be added to the patient if the IPP measurement is below a threshold for performing an adequate PD fill. The steps of 902-918 can be repeated until the adjusted IPP measurement is between 16 and 19 cm of H20 or between 0.25 and 0.28 psig, which indicates an adequate fill volume for PD treatment. The fill volume parameter is then determined based on the patient's characteristics and / or the amount of PD fluid detected to be infused to the patient's peritoneal cavity. The fill volume parameter can then be used for subsequent PD treatments, i.e., continuous ambulatory peritoneal dialysis ("CAPD") treatment using a PD machine or manually. The example procedure 900 then ends.

[0090] In some embodiments, the patient can wear a force sensor. For example, the force sensor can be attached to the patient's wrist or abdomen. Output data from the sensor provides additional data indicative of patient movement. The force sensor worn by the patient can be used with the force sensor 802 provided with the pressure sensor 306. Alternatively, only a force sensor attached to the patient is provided. In some cases, data from the force sensor attached to the patient is tracked over time along with IPP measurements. For example, the patient can perform routine work or a set of activities with the transfer set 102 attached. The IPP measurements can be correlated with the force data (with force-related components removed) to identify how the patient's IPP changes for different orientations and / or activities. The clinician can use this correlation to ensure that the fill volume does not cause the patient's IPP to exceed clinically recommended limits regardless of the patient's position or activity during treatment, thereby improving patient comfort during treatment. The fill volume determined by the clinician can then be set in the patient's treatment or device prescription and downloaded to the patient's cycler or peritoneal dialysis machine, either locally or remotely.

[0091] III. IPP measurement verification embodiment

[0092] In some embodiments, the processor 310 and / or the portable device 402 are configured to validate the IPP measurement data prior to processing the data. For example, as shown in block 908, the processor 310 and / or the portable device 402 compare the received IPP measurement data to one or more ranges or thresholds that indicate significant patient and / or sensor movement. This operation can also include comparison to one or more ranges and / or limits that correspond to normal fill pressures and / or expected IPP measurements. IPP measurements that fall outside of this range and / or limit can indicate problems with the catheter connection, a clogged catheter, a leak in the transfer set, or other fluid connectivity problems. Figure 9

[0093] Figure 11 A graph 1100 showing IPP measurements compared to one or more ranges and / or thresholds in accordance with example embodiments of the present disclosure is shown. The graph 1100 includes a first range 1102 that corresponds to pressure measurements that can be accepted when PD fluid is being infused into a patient's abdominal cavity. During PD fluid fill, forces are applied to the sensor element (e.g., the transducer membrane) due to fluid flow. The first range 1102 can be relevant to gravity fed fluid infusions, while a second range can be used if a pump is providing the PD fluid.

[0094] The graph 1100 also includes a second range 1104 that corresponds to a pressure drop due to a clog in the transfer set or catheter portion. During the fill phase, the processor 310 and / or the portable device 402 receives IPP measurement data and compares the data to the first range 1102 and the second range 1104. If the IPP measurement data corresponds to the second range 1104, the processor 310 and / or the portable device 402 can generate an alert or other message / indication that there is a problem with the catheter and / or transfer set. In addition, the processor 310 and / or the portable device 402 can prevent processing of subsequent IPP measurements until it is confirmed that the patient has been properly filled with PD fluid.

[0095] The graph 1100 shows that the pressure measurement data decreases over time. This decrease is a result of the decreasing flow rate as the gravity fed PD fluid bag empties into the patient. In some cases, the ranges 1102 and 1104 can have corresponding decreases over time to account for the expected pressure drop during the PD fluid infusion. For simplicity, the pressure values on the y-axis are normalized.

[0096] ​The graph 1100 also includes a third range 1106 that applies after the flow of PD fluid has stopped and the fluid is allowed to dwell in the patient's abdominal cavity. The processor 310 and / or the portable device 402 can use the third range 1106 to identify IPP measurements that exceed the allowable pressure threshold, which can indicate patient movement, transfer set movement, or overfilling of the patient. IPP measurements that exceed the third range 1106 can be ignored by the processor 310 and / or the portable device 402. Additionally or alternatively, the processor 310 and / or the portable device 402 can generate an alert. It should be noted that IPP measurements increase over time as the PD fluid absorbs waste and other toxins from the patient, which increases the volume of fluid within the abdominal cavity, thereby increasing the measured pressure. The processor 310 and / or the portable device 402 can be configured to record IPP measurements over time to ensure that the PD fill volume does not exceed the allowable IPP during the dwell phase, which can cause discomfort to the patient during PD treatment.

[0097] Figure 12 A graph 1200 showing an alternative embodiment is shown in which the processor 310 and / or the portable device 402 uses the recorded bag fill head height values and bag solution volume to determine a threshold 1202 that corresponds to an expected fill pressure. When a pump is provided, an expected pump pressure value can instead be used. In this example, the processor 310 and / or the portable device 402 estimates the threshold based on actual fill conditions to more accurately determine whether there is a problem with injecting PD fluid into the patient's abdominal cavity. The graph 1100 and the graph 1200 can be displayed by the processor 310 and / or the portable device 402 to the clinician.

[0098] IV. IPP measurement value adjustment using patient information embodiment

[0099] During the IPP measurement, the processor 310 and / or the portable device 402 can adjust the IPP measurement value or fill volume parameter based on received patient information. In some cases, the patient's water retention can affect the abdominal cavity volume or the pressure provided on the abdominal cavity, which can affect the IPP measurement. In addition, the patient's blood pressure or heart rate can indicate whether the patient is in a stressed or tired state, which can affect the IPP measurement.

[0100] Figure 13is a diagram 1300 illustrating data processing by the processor 310 and / or the portable device 402 to adjust IPP measurements based on patient information, according to example embodiments of the present disclosure. As shown, the processor 310 and / or the portable device 402 receives IPP measurement data 903. The processor 310 and / or the portable device 402 can also receive urine data 1302, which indicates urine output by the patient in a certain time period prior to the IPP measurement, such as twenty-four or forty-eight hours prior. The urine output can be self-reported by the patient and keyed into the processor 310 and / or the portable device 402. In other cases, the urine output can be measured in a container and keyed into the processor 310 and / or the portable device 402.

[0101] The processor 310 and / or the portable device 402 also receives food and beverage consumption information 1304. This information provides an indication of how much food and beverage the patient consumed in the time period prior to the IPP measurement or between IPP measurements. The urine data 1302 and the food / beverage data 1304 together provide fluid balance information. The processor 310 and / or the portable device 402 is configured to calculate the fluid balance of the patient by adding the food / beverage data 1304 and subtracting the urine data 1302, and account for metabolic burning of fluids based on a population of patients of similar age, gender, height, and weight. The processor 310 and / or the portable device 402 then determines whether the fluid balance of the patient imposes a component on the IPP measurement by comparing the calculated balance information to a correlation of balance information and IPP measurements for patients of similar height, gender, weight, etc. The processor 310 and / or the portable device 402 then adjusts the IPP measurement data 903 by accounting for the IPP component related to the fluid balance. In cases where the fluid balance is negative, such as dehydration, the adjustment can result in an increase in the numerical value of the IPP measurement.

[0102] The processor 310 and / or the portable device 402 also receives heart rate and blood pressure data 1306. The processor 310 and / or the portable device 402 correlates the data 1306 to an IPP measurement component based on a population of patients of similar height, weight, gender, age, etc. The processor 310 and / or the portable device 402 then adjusts the IPP measurement value by identifying the resulting IPP measurement component.

[0103] After adjusting the IPP measurements, the processor 310 and / or the portable device 402 determines a fill volume parameter 917. As discussed above, this can include comparing the adjusted IPP measurements (or a trend of the adjusted IPP measurements) to a fill IPP limit for the PD therapy. Once the IPP measurements approach but do not exceed the limit, the processor 310 and / or the portable device 402 determines a fill volume using the patient's body mass or by draining fluid and / or using a flow sensor to determine a PD fluid volume as the volume of PD fluid within the patient's abdominal cavity. The fill volume parameter 917 can then be used for subsequent PD treatments.

[0104] V. Vital capacity embodiment for determining fill volume

[0105] In the examples discussed above, IPP measurements have been taken using the pressure sensor 306. In some embodiments, the pressure sensor 306 can be replaced with a spirometry sensor, such as a spirometer. Spirometry has been shown to decrease with increasing IPP. The processor 310 and / or the portable device 402 can use a known correlation between spirometry and IPP measurements to determine a fill volume parameter for the patient without using a pressure sensor.

[0106] Figure 14 An example system 1400 is shown in accordance with example embodiments of the present disclosure in which a spirometer 1402 is used to take spirometry measurements to determine a fill volume parameter. Such spirometry measurements enable higher efficiency of IPP measurements that can otherwise result in the errors discussed above. Further, use of the spirometer 1402 enables use of standard transfer sets and catheters rather than transfer sets or catheters equipped with pressure sensors.

[0107] As Figure 14 shown, the spirometer 1402 measures the patient's respiratory capacity at different fill levels, shown as M0 (dry state), Ml (10% of fill capacity), M2 (20% of fill capacity), M3 (50% of fill capacity), etc. After the patient is filled to an estimated desired percentage of the cavity capacity, the spirometer 1402 records the patient's spirometry. The spirometer 1402 can record the spirometry for one or more breathing cycles to determine an average spirometry.

[0108] The example processor 310 and / or the portable device 402 receives spirometry data from the spirometer 1402. The processor 310 and / or the portable device 402 uses a known correlation between spirometry and IPP to adjust the IPP measurement to provide a more accurate measurement. The resulting IPP value can then be used to determine a fill volume and / or to identify when the PD fluid fill has reached a desired percentage of capacity to be effective for PD treatment. This fill volume is stored by the processor 310 and / or the portable device 402 as a fill volume parameter for use in the patient's PD treatment.

[0109] A patient-specific correlation between fill volume and spirometry can be determined and subsequently used for PD treatment. In these embodiments, the PD machine can use periodic spirometry measurements to estimate the IPP or fill volume of the patient during different stages of PD treatment. Figure 15 A graph 1500 of a patient-specific correlation between spirometry and fill volume according to an example embodiment of the present disclosure is shown. The graph 1500 shows that spirometry decreases as the PD fill volume increases. Such a correlation can be useful for PD treatment in which a spirometry measurement can be used instead of attempting to estimate or directly measure the IPP of the patient.

[0110] VI. Conclusion

[0111] It will be appreciated that various alterations and modifications to the presently preferred embodiments described herein will be apparent to those of ordinary skill in the art. Such alterations and modifications can be made without departing from the spirit and scope of the subject technology and without diminishing its intended advantages. It is therefore intended that such alterations and modifications be considered within the scope of the appended claims.

Claims

1. An intra-abdominal pressure ("IPP") measurement system, comprising: A fluid container that contains peritoneal dialysis ("PD") fluid; A transfer kit and a catheter, which are in fluid communication with the fluid container and configured to be in fluid communication with the patient's peritoneum, so that PD fluid can be delivered to the patient's peritoneum; A pressure sensor configured to contact the transfer kit or the drainage tube, the pressure sensor being configured to transmit output data indicating the intraperitoneal pressure (IPP) of the patient, the pressure sensor comprising... A pressure element configured to measure the pressure exerted by the fluid within the transfer kit or guide tube, and A pressure amplifier having a first side and a second side, the first side contacting a portion of the transfer kit or guide tube, the second side contacting the pressure element, and the first side having a larger diameter or surface area compared to the second side; as well as A processor, communicatively connected to the pressure sensor, is configured to... Receive the output data indicating the IPP within the patient's abdominal cavity. Receive force data indicating at least one of patient movement or pressure sensor movement, spirometry data indicating patient vital capacity, or patient information including at least one of urine output over a defined time period, food / beverage intake over a defined time period, heart rate, or blood pressure. The force data, the pulmonary volume measurement data, or patient information are used to adjust the output data indicative of the IPP, and At least one of the following: using the output data indicating the adjustment of the IPP to determine the fill volume parameter for PD treatment of the patient, or causing the output data indicating the adjustment of the IPP to be displayed so as to be able to determine the fill volume parameter.

2. The system according to claim 1, wherein, The first side includes a diameter or surface area that is at least twice the diameter or surface area of ​​the second side to provide at least twice the pressure amplification.

3. The system according to claim 1, wherein, The pressure element includes at least one of a piezoresistive strain gauge, a pressure sensing diaphragm, a capacitive diaphragm, a pressure sensing capsule, or a Boulden tube.

4. The system according to claim 1, wherein, The pressure sensor is integrally formed with the transfer kit or guide tube.

5. The system according to claim 1, wherein, The pressure sensor is mechanically connected to the transfer kit or the flow tube.

6. The system according to claim 1, wherein, The output data of the IPP indicating the patient's peritoneum corresponds to a pressure measurement performed by the pressure sensor during the retention interval between the supply of the PD fluid to the patient's peritoneum and the removal of the PD fluid from the patient's peritoneum.

7. The system according to claim 1 or 6, wherein, The fluid container is positioned at head height, and the system further includes a line clamp that, when closed, blocks the flow of the PD fluid through the transfer kit or guide tube.

8. The system of claim 1 or 6, further comprising a pump configured to move PD fluid from the fluid container through the transfer kit and the tubing to the patient's abdominal cavity upon activation.

9. The system of claim 1, 6 or 8, further comprising an automated peritoneal dialysis ("APD") machine configured to provide the PD treatment to the patient using at least the filling volume parameter.

10. The system of claim 1, 6, 8, or 9, further comprising a force sensor included on the pressure sensor or adapted to contact the transfer kit or guide tube, the force sensor comprising at least one of an inertial sensor, a gyroscope, or an accelerometer for sensing at least one of linear or rotational accelerations on one or more axes. in, The force sensor is configured to output the force data.

11. The system according to claim 10, wherein, The processor is further configured to receive the force data and use the force data to adjust the output data indicative of the IPP to calculate at least one measurement component associated with patient movement or pressure sensor movement.

12. The system according to claim 1 or 11, wherein, The processor is further configured to: The output data indicating the IPP is compared with at least one data range; When the comparison is outside the at least one data range, it provides an indication that at least one of the transfer kit or the guide tube has a problem; as well as When the comparison is within the at least one data range, the output data indicating the IPP is used to determine the fill volume parameter.

13. The system according to claim 12, wherein, The processor is further configured to: A second output data is received from the pressure sensor, the second output data indicating the pressure during the filling of the patient's abdominal cavity with an increased amount of the PD fluid; The second output data, indicating the pressure during the filling of the patient's abdominal cavity, is compared with a second data range; When the comparison is outside the second data range, it provides an indication that at least one of the transfer kit or the guide tube has a problem; as well as When the comparison is within the second data range, the output data indicating the IPP is used to determine the fill volume parameter.

14. The system according to claim 1, wherein, The defined time period includes at least one of twenty-four hours or forty-eight hours prior to the pressure sensor providing output data indicative of the patient's IPP.

15. The system according to claim 1, further comprising: A spirometer, the spirometer being used to transmit the lung volume measurement data.

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