Body fluid management system for patient care

Abstract

There is provided herein a bodily fluid management system for patient care, the bodily fluid management system comprising, in an operable combination: a control system component comprising a fluid flow detection and control subassembly; a user data interface; a patient interface assembly including a wearable pressure sensor subassembly having a pressure sensor in the path of the bodily fluid for direct attachment to a patient proximate to an anatomical marker and a directional sensor in the path of the bodily fluid, the directional sensor is used to monitor and / or control the pressure and / or flow rate of bodily fluids such as cerebrospinal fluid, blood or urine.

Description

[0001] Cross-references to related applications

[0002] This PCT patent application was filed on September 3, 2021, as PCT / US21 / 49118, and claims the benefit of U.S. Provisional Patent Application No. 63 / 074,223, filed on September 3, 2020. The contents of U.S. Provisional Patent Application No. 63 / 074,223 are incorporated herein by reference in their entirety. Technical Field

[0003] This disclosure generally relates to the medical field, and more specifically to medical devices and associated procedures for monitoring and / or controlling body fluid pressure, drainage rate, and patient movement. This document discloses body fluid management systems for human and animal use that provide real-time and integrated control of body fluid pressure and drainage rate to accommodate frequent changes in orientation and / or movement of non-stationary patients. Background Technology

[0004] The medical benefits of managing body fluid pressure by monitoring and controlling the drainage of body fluids in various clinical situations have been documented in the medical literature. This is particularly relevant in cases where abnormal displacement, changes in vascular wall compliance, or overproduction or damage to natural drainage channels can lead to fluid accumulation in individual organs or body compartments. Excess fluid in an individual body compartment can cause increased pressure, especially in cases of low compliance. Compartment syndrome refers to an increase in pressure between compartments to a level that impairs circulation, leading to insufficient oxygenated blood supply and consequently irreversible tissue ischemia and necrosis. See, for example, Garner's *Journal of the Hospital for Special Surgery, New York*. HSS J ) 10(2) : 143 (2014); Keddissi, Canadian Journal of Respiratory Therapy ( Can. J. Respir. Ther. ) 55 (2018); Marik, Chest ( Chest ) 134 :172-178 (2008); Trinooson, Journal of the American Association of Nurses Anesthetists ( AANA J ) 81(5) :357-368 (2013); Frazee, Nephrology ( Kidney Dis. ) 2 :64-71 (2016); Bhave, Journal of the American Society of Nephrology ( J Am Soc Nephrol )》22:2166-2181 (2011); Bruce 《Journal of Neuro-Ophthalmology》22:2166-2181 (2011); J Neuroophthalmol. ) 34(3) :288-294(2014); van der Jagt, Emergency Care ( Critical Care) 20 :126 (2016); and Lee's Neuro-Ophthalmology ( Neuro-Ophthalmol ) 34: 278-283 (2014).

[0005] Risk factors associated with various causes of acute compartment syndrome due to anatomical compartments have been identified in the medical literature. In the extremities, fractures have been found to be the most common cause, with muscles and nerves at the highest risk. In the brain, numerous causes have been identified, including traumatic brain injury, stroke, infection, tumors, and congenital hydrocephalus. This can be explained by the Monro-Kellie Doctrine, which considers blood, cerebrospinal fluid, and brain tissue (including interstitial fluid) as the primary variables driving pressure in the head. In the peritoneal cavity, the most documented risk factor is the severity of the patient's condition. Up to 50% of intensive care patients have been found to have elevated intra-abdominal pressure (IAP), putting them at risk of reduced abdominal organ perfusion and potential organ failure. Intra-abdominal hypertension (IAH) has also been found to affect lung function in clinical practice. Therefore, in addition to monitoring treatment-associated functions, monitoring patients at risk for compartment syndrome is employed. See Garner, *American Journal of Special Surgery, New York*. 10(2) : 143 (2014); Hunt, Journal of Trauma Management and Outcomes ( J. Trauma Management. Outcomes ) 8 :2 (2014); and Mokri, Neurology ( Neurology ) 56(12) :1746 (2001).

[0006] Gravity-based drainage of bodily fluids (including as a treatment for increased pressure on the body) has been practiced for centuries, with significant improvements made over time. Unrestricted drainage devices, such as catheters, designed to completely drain fluids from bodily compartments, have been in use for 3,500 years. The controlled partial drainage of cerebrospinal fluid to relieve pressure on the brain was first documented by Claude-Nicholas Le Cat in 1744, and William Williams Keen documented the method in the art in 1890. See Feneley's *Journal of Medical Engineering and Technology* (…). J ME & T )》3 9(8) :459 (2015) and Srinivasan, Journal of Neurosurgery ( J Neurosurgery ) 120 :228 (2014).

[0007] In 1927, the technique was further advanced with the introduction of a manometer, which added fluid pressure measurement for the drainage of bodily fluids. The manometer utilizes the height difference of a fluid column to measure pressure. When used in a medical setting, a rod-mounted manometer is aligned with the height of an external anatomical landmark and has clinically proven to approximate the pressure of the compartment being measured. In cases of intracranial pressure, the external auditory canal or tragus is used to approximate the interventricular foramen in the brain when the patient is in a supine position. When measuring arterial pressure, the mid-axillary line of the fourth intercostal space is often used to approximate the heart. The device is then opened to atmospheric pressure to “zero” the system, which sets the baseline level of the manometer, thereby determining the pressure differential in the system. See Srinivasan, *Journal of Neurosurgery* 120:228 (2014) and Muralidharan, *International Journal of Surgical Neurology*. Surg Neurol Int ) 6 (Supplement 6) :S271 (2015).

[0008] Further advances in this field allow the pressure gauge to be used as a univariate Boolean function to control cerebrospinal fluid (CSF) drainage based on whether the patient's pressure is above or below a single target value. In this case, the outlet end is raised to the height of the target intracranial pressure (ICP), and the inlet end is attached to a lumbar or ventricular catheter. When the pressure in the target compartment, such as the skull or spine, exceeds the back pressure generated by the height of the water column in the outlet end, CSF flows until equilibrium is restored. Thus, this simulated system can drain fluid until the system reaches the target pressure. See Srinivasan, *Journal of Neurosurgery*. 120 :228 (2014) and Muralidharan, *International Journal of Surgical Neurology* 6 (Supplement 6) :S271 (2015).

[0009] While using a pressure gauge in this binary manner to control CSF drainage remains common practice, external pressure transducer assemblies are now often connected to the outlet of the pressure gauge fluid line via a stopcock valve. When connected to pressure monitoring devices, such as those used for invasive arterial blood pressure monitoring, this combination allows for intermittent measurement of ICP values ​​and visualization of ICP waveforms. This is achieved by the clinical user manually pausing the drainage and using the stopcock valve to mechanically redirect the fluid to the pressure monitoring system.

[0010] Despite advancements in this field over the past century, limitations and risks in existing systems represent an unmet need in the field of fluid management systems. Because manometers rely on the alignment of the height of the fluid column, mounted on a rod, with an anatomical reference, these systems depend on a stationary patient. Given the low-pressure column height relative to the patient's anatomy, manometers are highly sensitive to patient position and movement. Even minor changes in patient position, such as turning the head, adjusting the patient to reduce pressure injury, or a change in bedside positioning, can lead to rapid over / under-drainage, resulting in disability or death. Therefore, these systems must be continuously maintained and adjusted to compensate for any patient movement. While keeping the patient sedated is logically simpler, this introduces numerous medical risks and other disadvantages for patients, families, and healthcare providers. Nevertheless, the risks associated with manometer-based drainage necessitate continuous clinical monitoring. Medical publications have noted the potential for improved outcomes in early post-stroke mobility and have pointed to ways to circumvent existing technological limitations to achieve this. This suggests that inventions that favor patient mobility may help reduce long-term disability rates. See, for example, Azuh, *American Journal of Medicine*. Am J Med ) 129(8) :866 (2016) and Mulkey's Journal of Neuroscience ( J Neuroscience )》46(3):153 (2014).

[0011] More broadly, pressure gauges lack the ability for users to select the desired flow rate, and current practice involves manually adjusting the target pressure up and down until the desired flow rate is indirectly approximated. Pressure gauges do not monitor drainage volume or provide any closed-loop behavior. They require clinical users to visually estimate and manually annotate drainage volume, rather than through automated, quantitative monitoring and reporting. In clinical use, this is known to result in varying levels of accuracy depending on the user's skill. Furthermore, pressure gauge drainage systems are subject to highly variable flow resistance, leading to inconsistent and unreliable drainage, a phenomenon detailed in public training materials for such devices. In these systems, drainage should begin as soon as the inlet pressure to the pressure gauge exceeds the back pressure generated by the height of the water column within the gauge.

[0012] For example, if a patient is at equilibrium at 10 cmH2O, and the ICP suddenly spikes to 15 cmH2O, the gauge should overflow and drainage should begin to restore pressure equilibrium to the 10 cmH2O set point. However, in order to initiate (or maintain) flow in the drainage line, the fluid must overcome flow resistance along the entire length of the drainage line. Because flow resistance can be strongly influenced by tissue debris, air gaps or large air bubbles in the drainage line, microbubbles adhering to the inner wall of the drainage line, manufacturing deviations in component and assembly operations (tolerances, adhesive ejection during bonding operations, etc.), and various other factors, drainage may not begin until the ICP has significantly increased beyond the desired set point, and may stop before restoring equilibrium to the set point. Because ICP values ​​are so small in absolute terms, flow resistance can be quite large relative to clinically significant changes in ICP. Due to the physical characteristics of gauge-based drainage devices, observed unreliable and inconsistent drainage is largely unavoidable.

[0013] A pressure gauge and an external pressure transducer can be paired (as is often used clinically) to construct a fluid management system that provides fluid pressure monitoring and fluid drainage; however, such a fluid management system cannot be used to measure fluid pressure while controlling fluid drainage. Therefore, this pairing lacks the ability to provide continuous monitoring and drainage, increasing the risk of not being able to detect complications in a timely manner.

[0014] Existing technology does include recently added, more sophisticated catheters that allow pressure transducer assemblies to be connected in parallel with drainage pressure gauges to allow for continuous monitoring. This approach creates a non-communicating, parallel activity displayed to the user, rather than an integrated system. This method still relies on the pressure gauge to control drainage based on Boolean thresholds, including pressure gauge limitations.

[0015] Existing external pressure monitoring technologies are subject to bias, resulting in a lack of accuracy, which is particularly relevant in anatomical compartments where pressure is represented by small values, and even minute variations within a narrow range are clinically significant. In most mammals, this would include various compartment pressures such as ICP, CVP, IAP, etc. These values ​​are measured in millimeters of mercury (mmHg) or centimeters of water (cmH2O). When considering, for example, ICP in humans, normal values ​​for infants are typically expressed as <5 mmHg, while for supine adults it is typically 7 to 15 mmHg, depending on the patient. In the case of IAP, normal adult values ​​are 5 to 7 mmHg, and in children they are typically 0 to 5 mmHg. This is compared to a wider range of arterial pressure values ​​of 60 to 120 mmHg. In clinical practice, they typically have an accuracy on the order of ±2 mmHg in practical use due to sensor bias. However, clinically significant biases for the various pressure parameters of interest (ICP, CVP, IAP, etc.) are on the order of several cmH2O. Therefore, the best-case scenario for results derived from these sensors is a delay in clinical use until the patient's condition worsens, and the worst-case scenario is misleading. Given that the function of the brain, heart, and other organs is crucial not only for recovery from acute illness but also for the patient's long-term quality of life, early detection of true changes in these values ​​would be a significant improvement over current technologies.

[0016] Recently introduced diaphragm transducers for obtaining clinically relevant accuracy typically have low natural resonant frequencies and may be affected by undesirable oscillations caused by physiological functions such as heartbeat.

[0017] Because none of these systems can detect sensor misalignment or malfunction, they must rely on complex protocols, custom sensor configurations, or continuous manual recalibration to temporarily achieve the precision and accuracy required to provide the existing clinical benefits. These labor-intensive adaptations and the risks they introduce hinder the wider adoption of core fluid drainage techniques.

[0018] Another drawback of the existing invention is the perfusion pressure region (i.e., the net pressure of fluid entering an organ or tissue (usually an anatomical compartment) through the circulatory or lymphatic system). Perfusion pressure includes cerebral perfusion pressure (CPP), which is the net pressure gradient that causes blood flow to the brain (cerebral perfusion). This must be maintained within a narrow range because too low a pressure can lead to cerebral ischemia (insufficient blood flow), and too high a pressure can increase intracranial pressure (ICP).

[0019] Perfusion pressure measurement is clinically relevant to managing compartment pressure and preventing compartment syndrome, where increased pressure within an anatomical compartment of the body can lead to insufficient blood supply to the tissues within that space. See Peitzman, *The Trauma Handbook: Trauma and Emergency Surgery*. The Trauma Manual: Trauma and acute Care Surgery Lippincott Williams & Wilkins (2012). Individual fluid pressure is often the input for clinical management of perfusion pressure and is used in the mathematical formula for calculating perfusion pressure (i.e., cerebrospinal fluid perfusion pressure = MAP - lumbar pressure). Automation of activities and calculations is still needed in the field, which are currently performed by clinicians such as nurses using multiple systems and manual analysis.

[0020] When calculating perfusion pressure, MAP values ​​are typically obtained from an invasive arterial blood pressure monitor, which nurses are trained to align with the mid-axillary line and the fourth intercostal space, as these are anatomical landmarks of the heart's location. When the patient is supine, the height of the fluid column driving the pressure becomes fairly constant in the horizontal plane. However, patients are often adjusted to a 30-degree head-of-bed position. In this position, the calculation of MAP values ​​will differ if the anatomical landmarks of the compartment fluid are referenced to those of the heart. Inconsistencies in practice, and even among nurse educators, result in variability in calculated CPP values ​​due to patient position. This can lead to undesirable outcomes and hinder medical innovation.

[0021] Furthermore, the perfusion pressure is calculated by the patient monitor as a result of multiple devices providing values ​​to the display in a unidirectional parallel manner. This monitoring and communication function is completely separated from drainage. Existing technology does not support integrated multimodal analysis and management. It cannot control drainage based on these calculated perfusion pressure values.

[0022] When perfusion pressure is considered in a clinical setting, the inability of existing technologies to sense or characterize patient movement presents unexpected opportunities for improvement beyond the accuracy of real-time drainage. For example, current systems cannot distinguish between clinically indicated changes in compartment pressure and anticipated, predictable changes due to changes in patient position or movement. Currently, this necessitates immediate care responses to alarms, leading to alarm fatigue. It also requires manual annotation of patient data so that trend information can be used to assess patient condition. It does not provide an efficient method for mapping the impact of patient movement or position on compartment pressure. Finally, it obscures other useful datasets that could advance the field in fluid management or broader medical understanding.

[0023] Other analog devices can be used to drain fluid when the primary purpose of fluid drainage is not to achieve a specific pressure value. Apart from syringes used in manual fluid sampling, existing systems are also gravity-based and can be described as volume-restricting and unrestricted drainage devices. Volume-restricting drainage devices are completely disposable analog catheters that rely on the mechanical constraint of a fully bulbous tube to stop drainage. Compared to a pressure gauge typically attached to a drainage bag capable of holding more than 500 ml of fluid, a volume-restricting catheter may only have a capacity of 30 ml and is removed after draining 30 ml. Unrestricted drainage devices, such as urinary catheters, surgical drainage devices, or wound management devices, are also analog catheters designed to completely drain fluid from a body compartment. They can be indwelling or used intermittently. Neither volume-restricting nor unrestricted drainage devices can be used to measure pressure, nor can they drain fluid based on a target pressure. Although drainage rate is an important variable, and clinicians prefer to control it according to the patient's condition, both lack the ability for the user to specify the desired flow rate. These different simulated drainage systems also require the use of markings on the drainage bags to visually estimate the drainage volume, because they lack quantitative calculations and reporting of drainage volume.

[0024] While existing fluid management systems offer some clinical benefits, particularly when multiple devices are used in combination, there remains a need for an integrated system for real-time fluid pressure monitoring and fluid drainage control that allows patient mobility without continuous medical supervision or intervention. Therefore, an unmet need remains in the art for a fluid management system that allows for the monitoring and management of fluid pressure in non-stationary patients. Summary of the Invention

[0025] This disclosure addresses unmet needs in the art and offers additional advantages over existing technologies by providing a fluid management system that employs digital technology to allow real-time monitoring and control of fluid pressure or drainage flow rate, while accommodating or taking into account patient movement. The combined use of various sensing modalities achieves improved accuracy, control, data capture, patient safety, and patient mobility compared to systems described in the prior art. Furthermore, the integration of drainage control and multi-fluid pressure monitoring into a single system enables automated therapeutic interventions based on derived physiological parameters such as perfusion pressure, which is unprecedented in the art.

[0026] Therefore, in some embodiments, this disclosure provides a body fluid management system comprising: a control system component for real-time monitoring of body fluid pressure and integrated control of body fluid drainage; and a patient interface component including a wearable pressure sensor sub-component for attachment to patient anatomical markers, the wearable pressure sensor sub-component including a pressure sensor and an orientation sensor in the path of the body fluid. In some aspects, the control system component is configured to detect changes in body fluid pressure, patient movement, or patient orientation based on input from the patient interface component. In other aspects, the control system component is configured with algorithms to correct or issue alarms for the flow rate of body fluid drainage based on user-defined settings.

[0027] In some aspects of these embodiments, the body fluid management system includes a control system component having a fluid flow detection and control subcomponent operatively communicating with a user interface subcomponent, which includes a graphical user interface, such as a graphical user interface configured to display pressure waveforms. In related aspects, the fluid flow detection and control subcomponent includes a flow rate control actuator, a flow cut-off actuator, and a body fluid flow detector operatively communicating with each other.

[0028] In other aspects of these embodiments, the body fluid management system includes a wearable pressure sensor subassembly having a plurality of pressure sensors in a body fluid path, wherein the plurality of pressure sensors includes a first pressure sensor and a second pressure sensor at a fixed interval, and wherein the plurality of pressure sensors and the orientation sensor are configured on a rigid member for detecting offset in one or more of the plurality of pressure sensors based on the difference between a anticipated differential pressure between the first pressure sensor and the second pressure sensor and an actual differential pressure between the first pressure sensor and the second pressure sensor.

[0029] In related aspects of these embodiments, the body fluid management system includes a patient interface component having a body fluid infusion chamber, a fluid drainage tube for connection to the control system component, a drainage tube for body fluid drainage, and a cable for transmitting signals from the wearable pressure sensor sub-component to the fluid drainage tube.

[0030] In some of the body fluid management systems disclosed herein, the body fluid is cerebrospinal fluid (CSF), and the control system components are configured to monitor intracranial pressure (ICP) in real time and integrate control of CSF drainage. In a related aspect, the patient interface component includes a drainage tube and a wearable pressure sensor sub-assembly, the drainage tube being configured at its proximal end to connect to a ventricular catheter, and the wearable pressure sensor sub-assembly being configured to attach close to the patient's external auditory canal (EAM).

[0031] In related embodiments, the body fluid management system disclosed herein further includes an infusion source configured to be connected to a control system assembly via a bidirectional infusion and drainage tube, wherein the control system assembly includes a pump for pumping fluid from the infusion source into a body cavity. In some aspects of these embodiments, the control system assembly is configured to monitor intra-abdominal pressure in real time, and the patient interface assembly includes a drainage tube configured to connect to a urinary catheter at its proximal end. In other aspects, the body cavity is the bladder.

[0032] In another embodiment of this disclosure, a system for determining perfusion pressure is provided, comprising: a control system component for real-time monitoring of body fluid pressure and integrated control of body fluid drainage from a body compartment, wherein the control system component is configured with a pump and an algorithm, the pump for pumping fluid from an infusion source to a secondary fluid line, and the algorithm responding to signals from a first wearable pressure sensor sub-component and a second wearable pressure sensor sub-component to correct or issue an alarm based on user-defined settings for the flow rate of body fluid drainage.

[0033] The system for determining perfusion pressure according to these embodiments includes a patient interface assembly having: a main fluid line configured at its proximal end to connect to a catheter inserted into the body fluid compartment and at its distal end to a removable fluid drainage reservoir; and a first wearable pressure sensor subassembly for attachment to an anatomical marker proximal to the body fluid compartment, wherein the first wearable pressure sensor subassembly includes a first pressure sensor in the path of the body fluid and an orientation sensor, the first pressure sensor and the orientation sensor being configured to detect changes in body fluid pressure and patient movement and orientation and to signal these changes. The system notifies the control system component; a secondary fluid line configured to connect to an arterial catheter at its proximal end and to the infusion source at its distal end; a second wearable pressure sensor subassembly for attachment to anatomical markers to monitor blood pressure, wherein the second wearable pressure sensor subassembly includes a second pressure sensor in the path of the blood and an orientation sensor, the second pressure sensor and the orientation sensor being configured to detect changes in blood pressure and patient movement and orientation and signal these changes to the control system component, wherein the perfusion pressure is calculated based on the measured blood pressure and body compartment fluid pressure.

[0034] In some aspects of these embodiments, the control system component includes a fluid flow detection and control sub-component operatively communicating with a user interface sub-component, which includes a graphical user interface, such as a graphical user interface configured to display pressure waveforms. In related aspects, the fluid flow detection and control sub-component includes a flow rate control actuator, a flow cut-off actuator, and a body fluid flow detector operatively communicating with each other.

[0035] In other aspects of these embodiments, the first wearable pressure sensor subassembly includes a first pressure sensor and a second pressure sensor in a body fluid path, wherein the first pressure sensor and the second pressure sensor are at a fixed interval, and wherein the first pressure sensor, the second pressure sensor, and an orientation sensor are configured on a rigid member to detect an offset in the first pressure sensor or the second pressure sensor based on the difference between an expected differential pressure between the first pressure sensor and the second pressure sensor and an actual differential pressure between the first pressure sensor and the second pressure sensor.

[0036] In another aspect of these embodiments, the second wearable pressure sensor subassembly includes a third pressure sensor and a fourth pressure sensor in the blood pathway, wherein the third pressure sensor and the fourth pressure sensor are at a fixed interval, and wherein the third pressure sensor and the fourth pressure sensor, along with an orientation sensor, are configured on a rigid member to detect offset in the third pressure sensor or the fourth pressure sensor based on the difference between a anticipated differential pressure between the third pressure sensor and the fourth pressure sensor and an actual differential pressure between the third pressure sensor and the fourth pressure sensor.

[0037] In related aspects, the patient interface component includes a body fluid infusion chamber, a fluid drainage tube for connection to the control system component, a drainage tube for body fluid drainage, and a cable for transmitting signals from the wearable pressure sensor sub-component to the fluid drainage tube.

[0038] In other aspects, the body fluid is cerebrospinal fluid (CSF), the control system component is configured to monitor intracranial pressure (ICP) in real time and integrate control of CSF drainage, the patient interface component includes a drainage tube configured to connect to a ventricular catheter at its proximal end, and a wearable pressure sensor sub-component is configured to attach close to the patient's external auditory canal (EAM).

[0039] In another aspect, the system according to these embodiments includes connections for an infusion source and a bidirectional infusion and drainage tube, wherein the control system component includes a pump for pumping fluid from the infusion source into the body cavity. In a related aspect, the control system component is configured to monitor intra-abdominal pressure in real time, and the patient interface component includes a drainage tube configured at its proximal end to connect to a urinary catheter. In another aspect, the body cavity is the bladder.

[0040] This disclosure also provides wearable pressure sensor subassemblies comprising a plurality of pressure sensors in the path of a body fluid and an orientation sensor, wherein the plurality of pressure sensors and the orientation sensor are configured to detect changes in body fluid pressure, patient movement, or patient orientation. In some aspects, the wearable pressure sensor subassemblies are configured to attach close to anatomical landmarks of the patient. In other aspects, the plurality of pressure sensors includes a first pressure sensor and a second pressure sensor at a fixed interval, and the plurality of pressure sensors and the orientation sensor are disposed on a rigid member to detect offsets in the first and second pressure sensors based on the difference between a anticipated differential pressure between the first and second pressure sensors and an actual differential pressure between the first and second pressure sensors.

[0041] In another aspect of these embodiments, a wearable pressure sensor subassembly is configured to attach to the patient's external auditory canal (EAM), and multiple pressure sensors and orientation sensors are configured to detect changes in intracranial pressure (ICP).

[0042] The various fluid management systems disclosed herein offer specific advantages for monitoring and controlling fluid pressure and flow rate in active patients, wherein real-time monitoring of fluid pressure and integrated control of fluid drainage flow rate result in improved patient care through enhanced automation, greater opportunities for patient mobility, and reduced reliance on healthcare professionals for continuous fluid pressure monitoring and system calibration (as required by existing fluid pressure management systems in the prior art).

[0043] These and other related aspects of this disclosure will be better understood through the following accompanying drawings and detailed description, which illustrate certain aspects of various embodiments. Attached Figure Description

[0044] Certain aspects of this disclosure will become more apparent from the accompanying drawings, which are presented for illustration and not limitation.

[0045] Figure 1 This is a line drawing showing a front perspective view of control system components according to certain embodiments of a currently disclosed body fluid management system. The control system components according to these embodiments are configured to interact with a patient interface component (such as...). Figure 4 (As described and further described in detail herein) can be used in combination.

[0046] Figure 2 This is a line drawing showing a rear perspective view of a control system component according to certain embodiments of a currently disclosed body fluid management system.

[0047] Figure 3 ( Figure 3A and Figure 3B( ) is a line diagram showing an exemplary flow rate control actuator in a control system component according to certain embodiments of a currently disclosed fluid management system. Figure 3A The flow rate control actuator shown uses a collet fixedly attached to the lead screw. Figure 3B The flow rate control actuator shown uses a spring-loaded chuck.

[0048] Figure 4 This is a line drawing of a perspective view of a patient interface component according to an embodiment of a currently disclosed portable system for managing body fluid pressure and drainage flow rate. Figure 4 As shown, the patient interface component is configured to be removably inserted into the control system component (such as...). Figure 1 and Figure 2 The control system components described are incorporated into and operably combined with them.

[0049] Figure 5 This is a line diagram depicting an embodiment of a patient interface component in relation to the patient's anatomy, wherein the pressure sensor component is sutured directly to the skin on the patient's head, substantially close to known anatomical landmarks.

[0050] Figure 6 An alternative embodiment is described, in which the pressure sensor assembly is constrained near the anatomical marker via a wearable device.

[0051] Figure 7 An alternative embodiment is described, in which the pressure sensor assembly is constrained near the anatomical marker via a wearable device.

[0052] Figure 8 This is a line diagram of an exemplary wearable pressure sensor sub-assembly used in certain embodiments of the patient interface components disclosed herein.

[0053] Figure 9 ( Figure 9A and Figure 9B ( ) is a schematic representation of a wearable pressure sensor sub-assembly according to certain embodiments of the present disclosure.

[0054] Figure 10 An embodiment of a currently disclosed fluid management system is described, which is configured to manage intracranial pressure (ICP) and cerebrospinal fluid (CSF) drainage, wherein a patient interface component is connected to a ventricular catheter at the proximal end of the drainage tube.

[0055] Figure 11 An embodiment of a currently disclosed body fluid management system is described, wherein a patient interface component is configured to connect to an indwelling urinary catheter, and a control system component is configured to actuate a pumping mechanism to periodically flush the bladder and the urinary catheter.

[0056] Figure 12An embodiment of a currently disclosed fluid management system is described, configured to obtain the necessary input to calculate real-time CPP, wherein the system includes multiple wearable sensor components, wherein a first wearable sensor component is attached to the patient substantially in close proximity to an anatomical marker suitable for monitoring ICP, and a second wearable sensor component is attached to the patient substantially in close proximity to an anatomical marker suitable for monitoring blood pressure. Detailed Implementation

[0057] This disclosure provides a body fluid management system that employs digital technology to allow real-time monitoring and control of body fluid pressure or drainage flow rate, while allowing or taking into account patient mobility. In some embodiments, the portable system according to this disclosure includes, in an operative combination, (1) a control system component and (2) a patient interface component. The body fluid management system disclosed herein exhibits unexpected and surprising advantages over currently available devices and techniques in the art for monitoring and managing body fluid pressure and flow rate.

[0058] This disclosure will be better understood in light of the following definitions, which are provided for clarification and not intended to limit the scope of the subject matter disclosed herein.

[0059] definition

[0060] Unless otherwise specifically defined herein, each term used in this disclosure has the same meaning as understood by one of skill in the art.

[0061] As used herein, the term "body fluid" generally refers to the fluid within the extracellular compartments of the human body (i.e., extracellular fluid (ECF)). These fluids include interstitial fluid not contained within blood vessels and intravascular fluid contained within blood vessels (such as venous fluid and arterial fluid). As used herein, "body fluid" includes fluids transcellularly located within compartments, such as those in the tracheobronchial tree, gastrointestinal tract, and bladder, and also includes fluids within cerebrospinal fluid and aqueous humor.

[0062] As used herein, the term "cerebrospinal fluid" or "CSF" refers to the sodium-rich, potassium-deficient tissue fluid of the brain and spinal cord. CSF supplies nutrients, removes waste products, and provides a buffer for the central nervous system to absorb mechanical shocks. CSF is typically watery, clear, colorless, and almost entirely cell-free. A normal adult has approximately 125 to 150 mL of CSF circulating within the ventricular system of the brain and spinal cord. Most CSF is produced within the two lateral ventricles.

[0063] As used herein, the term "fluid pressure" generally refers to the pressure exerted by "body fluid" contained in the extracellular compartment, and includes, for example, intracranial pressure, arterial pressure, central venous pressure, and intra-abdominal / bladder pressure.

[0064] As used in this article, the term “body compartment pressure” generally refers to the pressure within the extracellular compartment and includes, for example, the pressure within the head (intracranial pressure), abdomen (intra-abdominal pressure), and limbs.

[0065] As used in this article, the terms “compartment syndrome” and “compartmental hypertension” refer to abnormally elevated pressure within a compartment of the body, with “compartmental hypertension” characterized by a lower disease threshold compared to “compartment syndrome”.

[0066] As used in this article, the term “intracranial pressure” or “ICP” refers to the pressure exerted by cerebrospinal fluid (CSF) within the skull and on the brain tissue.

[0067] As used in this article, the term "arterial pressure" refers to blood pressure in the arterial vascular system. This term is often synonymous with the related term "mean arterial pressure" (MAP), which refers to an individual's average blood pressure over a single cardiac cycle. MAP is calculated using the peak systolic pressure (SP) during cardiac pumping / squeezing and the low diastolic pressure (DP) during cardiac diastole between pumping / beating, according to the expression MAP = DP + (SP - DP) / 3.

[0068] As used in this article, the term "central venous pressure" or "CVP" refers to the blood pressure in the vena cava near the right atrium of the heart.

[0069] As used herein, the term "accelerometer" refers to a type of "orientation sensor" capable of quantifying acceleration in one or more axial directions based on the inertial force of mass and Newton's second law, and generating a digital electrical signal (SPI, I2C, etc.) proportional to said acceleration. Such devices can be used to determine orientation (by measuring static acceleration due to gravity) and detect motion (by analyzing dynamic acceleration).

[0070] As used herein, the term "pressure sensor" refers to a device capable of quantifying pressure (and pressure changes) in a fluid (air, water, saline, bodily fluids, etc.) and generating an electrical signal proportional to said pressure (or pressure changes). As used herein, "pressure sensor" can also refer to a device configured to measure gauge pressure or absolute pressure.

[0071] As used herein, the term "anatomical landmark" refers to a non-invasively identifiable physiological attribute or feature, such as cephalometric landmarks, joints, or intercostal spaces, which may be clinically significant relative to their internal location. Examples include the external auditory canal (EAM) or glabella as anatomical landmarks commonly used in ICP calculations for the brain center or foramen of Monro, and the fourth intercostal space at the midaxillary line as an anatomical landmark for the location of the heart.

[0072] Words and phrases using singular or plural forms also include both singular and plural forms, respectively. For example, terms such as “one” or “a” and phrases such as “at least one” and “one or more” include both singular and plural forms. Terms intended to be “open” (including, for example, the words “comprise,” “comprising,” “include,” “including,” “have,” and “having”) should be understood in an inclusive sense, as opposed to an exclusive or exhaustive sense. That is, the term “including” should be interpreted as “including but not limited to,” the term “includes” should be interpreted as “including but not limited to,” and the term “have” should be interpreted as “at least having.”

[0073] The term “or” as used in the claims and supporting text is intended to mean “and / or” unless it is explicitly stated that it refers only to alternatives or that the alternatives are mutually exclusive, but this disclosure supports the definition of “and / or” as referring only to alternatives.

[0074] Additionally, when used in this application, the terms “this article,” “above,” “below,” and words with similar meanings refer to the entire application and not any particular part of it.

[0075] Furthermore, where features or aspects of this disclosure are described in accordance with the Markush group, this disclosure is also intended to be described in accordance with any single member or subgroup of members of the Markush group. Similarly, all scopes disclosed herein also cover all possible subscopes and combinations of subscopes, and languages ​​such as “between,” “at most,” “at least,” “greater than,” “less than,” etc., include the numbers listed in the scope and include each individual member.

[0076] All references cited in this article, whether above or below, including but not limited to patents, patent applications and patent publications (whether U.S., PCT, or foreign publications), as well as all technical, medical and / or scientific publications, are incorporated herein by reference in their entirety.

[0077] Body fluid management system

[0078] This article presents a body fluid management system that uses digital technology to allow for real-time integrated monitoring and control of body fluid pressure or drainage flow rate, while allowing or taking into account patient movement.

[0079] The exemplary body fluid management system disclosed herein is described with reference to the management of specific body fluids. However, it should be understood that the body fluid management system of this disclosure can be used to monitor and manage various extracellular and interstitial body fluids, including but not limited to cerebrospinal fluid, blood, urine, wound exudate, mucus, and semen. Furthermore, it should be understood that the body fluid management system of this disclosure can be used to monitor and manage various body compartments, including but not limited to intracranial space, intraperitoneal space, and limbs.

[0080] In some embodiments, the body fluid management system according to the present disclosure includes, in an operative combination, (1) a control system component and (2) a patient interface component.

[0081] In some aspects of these embodiments, the control system components may be durable, and the patient interface components may be disposable. In other aspects, the fluid management system disclosed herein may be entirely durable, have a cleanable or re-sterilizable patient interface component, or such a system may be entirely disposable.

[0082] The fluid management system disclosed herein can be selectively operated in a pressure control mode (e.g., by utilizing a pressure setpoint), a flow rate control mode (e.g., by utilizing a drainage flow rate setpoint), or a monitoring-only mode in response to user-configurable alarm thresholds, to collect pressure data or notify the user (e.g., an alarm).

[0083] Flow rate control and pressure control modes can be implemented in the same way: by controlling the drainage of associated bodily fluids. This can be achieved through a flexible tube in the patient interface assembly, which is variablely or intermittently compressed by a flow rate control actuator in the control system assembly. Algorithms can be used to provide closed-loop control of the flow rate control actuator based on inputs from various sensors in the system.

[0084] The siphon effect can be maintained by using a drainage line that is essentially filled with fluid, with its outlet lower than its inlet.

[0085] Drainage velocity measurement can be achieved by detecting falling droplets of fluid within a detection chamber (drip chamber, small transparent container, etc.), where the droplets have a substantially known volume. In such an arrangement, the system can count the droplets and calculate the flow rate based on the number of droplets over the time span of interest (e.g., mL / hr). Drainage velocity measurement can also be achieved using ultrasonic sensors, mass flow rate sensors, or any similar sensors capable of directly or indirectly measuring flow.

[0086] Pressure measurement can be achieved using two or more disposable pressure sensors located substantially close to the patient's anatomical landmarks, wherein: the pressure sensors are located within the drainage flow channel and are in direct communication with the patient's bodily fluids; these pressure sensors are shared within a housing attached to the patient's skin; the pressure sensors are rigidly mounted at defined intervals, allowing the difference in readings between the two sensors to detect sensor errors (offset, sensor malfunction, blockage, scaling, etc.); the orientation of the drainage flow channel is detected by an orientation sensor, thereby calculating the expected differential pressure between the two pressure sensors (based on the fluid density and the vertical component of the sensor spacing) and using it to enhance pressure sensor error detection; the stable (average) pressure is derived from variable pressure readings (such as those observable from ICP waveforms, systolic / diastolic blood pressure peaks, etc.) via a proprietary algorithm.

[0087] In some embodiments, the system may be configured to monitor and / or control the pressure or flow rate of a single fluid (CSF, blood, urine, etc.). In other embodiments, the system may be configured to monitor and / or control two or more fluids or anatomical subsystems (CSF and blood; bladder pressure and intra-abdominal pressure; etc.). In some embodiments, the system may include the calculation of derived parameters such as perfusion pressure (CPP, APP, SCPP, etc.), and the pressure or flow rate of a single fluid or body compartment may be monitored and / or controlled based on said derived parameters. In some embodiments, the system may include a peristaltic or similar pumping mechanism for controlling fluids other than the target bodily fluid (saline, artificial CSF, etc.) for purposes such as periodic flushing, back pressure (e.g., in the case of an arterial line).

[0088] 1. Control system components

[0089] In some embodiments, the control system components disclosed herein include (1) a fluid flow detection and control sub-component operatively communicating with (2) a user interface sub-component to enable real-time monitoring and control of body fluid pressure and drainage. In some aspects of these control system components, the fluid flow detection and control sub-component includes a primary flow rate control actuator, a secondary flow cut-off actuator, and a body fluid flow sensor operatively communicating with each other.

[0090] Figure 1 and Figure 2 This is a line diagram illustrating a perspective view of an exemplary control system component 10 according to certain embodiments of a currently disclosed body fluid management system, the exemplary control system component 10 being configured to interact with a patient interface component 50 (such as...). Figure 4 (As described herein and elsewhere) can be used in combination.

[0091] like Figure 1As depicted, the control system component 10 includes a fluid flow detection and control subcomponent 20 operably combined with a user interface subcomponent 40, which includes a user interface 42 for receiving user input (settings, patient information, etc.) and displaying system settings and outputs (setpoints, alarm thresholds, patient information, current or historical pressure or flow rate data, alarms, notifications, waveforms, etc.). In some embodiments, the user interface 42 may include a graphic display (LCD, OLED, etc.), a touchscreen (resistive, capacitive, projected capacitive, etc.), a keypad (plastic or elastomeric buttons, membrane switches, etc.), an LED array (7-segment, individual indicators, etc.), or any similar element suitable for inputting user input and displaying system settings and outputs.

[0092] like Figure 2 As depicted, the control system assembly 10 includes an adjustable clamping mechanism 14 for securing to an intravenous infusion stand 11, bed rail, or other similar ward furniture. In other embodiments, the control system assembly 10 may be configured for trolley mounting, wall mounting, or freestanding mounting.

[0093] In other respects, the control system component 10 includes a socket 12 for connecting to an external power source (AC power, DC network, etc.) and may optionally include an internal power source (rechargeable battery).

[0094] In another aspect, the control system component 10 may include an electrical interface (connector / socket, spring pin / spring-loaded contact array, etc.) for DC power distribution and electrical signal communication with the patient interface component 50. In other embodiments, such communication or power distribution may be implemented wirelessly.

[0095] In some embodiments, the fluid flow detection and control subassembly 20 and the user data interface subassembly 40 may each be encapsulated in a set of rigid (plastic, metal, etc.) housings and connected by a pivoting mechanism 48 (hinge, four-bar linkage, etc.) such that the subassemblies can pivotally open and close relative to each other. In some embodiments, the pivoting mechanism 48 may include features (eccentricity, cam, etc.) that provide one or more preferred positions (closed, fully open, etc.) to facilitate the installation / uninstallation of the fluid guide tube 60. Figure 1 The depicted features may include a handle 44 and a hand clearance feature 24 to facilitate operation of the pivoting mechanism 48. In an alternative embodiment, the control system 10 may comprise a single rigid housing that encloses both the fluid flow detection and control component 20 and the user interface sub-component 40, thus eliminating the need for the hinge 48, handle 24, and other associated features. In such embodiments, the recess 32 for receiving the fluid drainage tube 60 of the patient interface component 50 may be located adjacent to the graphical user interface 42.

[0096] In other aspects, the fluid flow detection and control sub-assembly 20 includes a recess 32, a drainage tube inlet 34, and a drainage tube outlet 26 for receiving the fluid drainage tube 60 and associated drainage tube 68 of the patient interface assembly 50 (in... Figure 4 (Depicted in Chinese).

[0097] exist Figure 1 Other aspects described include the fluid flow detection and control sub-assembly 20, which operably includes a primary flow rate control actuator 22 for controlling the flow rate of bodily fluids, a secondary flow cut-off actuator 30 for automatically cutting off the drainage flow in the event of power loss or system failure, and a bodily fluid flow detector 28 for detecting the drainage flow rate.

[0098] In some embodiments, the body fluid flow detector 28 may be an optical sensor, mass flow sensor, ultrasonic flow sensor, or any other similar sensor capable of detecting the flow of a target body fluid with clinically acceptable precision and accuracy for detecting falling droplets (such as droplets falling through a drip chamber, a small transparent container, or a similar housing).

[0099] In some embodiments, the secondary flow cut-off actuator 30 may be a DC motor with an encoder and a lead screw, a stepper motor with a lead screw, a servo motor, a solenoid, a linear actuator, an electromagnetic latch, or any other similar actuator or latching mechanism that can be actuated quickly enough to cut off the flow in the event of power loss or system failure.

[0100] In some embodiments, the primary flow rate control actuator 22 may be a DC motor with an encoder and a lead screw, a stepper motor with a lead screw, a servo motor, a solenoid, a linear actuator, or any other similar actuator that provides precise positioning for a substantially constant flow rate (as in the case of a motor with an encoder, a stepper motor, or a servo motor) or can be rapidly actuated between on / off states for intermittent flow (as in the case of a solenoid).

[0101] Figure 3A and Figure 3B An exemplary primary flow rate control actuator 22 is depicted, which can be advantageously used in a control system component 10 according to certain embodiments of a currently disclosed body fluid management system. (See also:) Figure 3A As shown, the primary flow rate control actuator 22 may include a stepper motor 92 having an integrated lead screw 96 and a fixed lead screw nut 94 to convert rotary motion into linear motion. A chuck 98 including a chuck tip 100 may be included to engage with the drainage tube 68 in the patient interface assembly 50. Figure 4 (Depicted in the middle) docking. In other embodiments, the chuck 98 can be replaced by a spring-loaded chuck 102, such as Figure 3BAs shown, this is to improve flow control accuracy or provide a substantially constant force in a fully clamped state, independent of any overtravel of the main flow control actuator.

[0102] In other embodiments, flow control or cutoff can be achieved via a rotary valve (plug valve, needle valve, etc.) in the patient interface assembly 50, which is variably rotated by a rotary actuator (servo motor, stepper motor, rotary solenoid, etc.) in the control assembly 10.

[0103] 2. Patient Interface Component

[0104] The patient interface components used in the body fluid management system disclosed herein include, in various operable combinations, a body fluid flow measurement interface, a flow rate control actuator interface, a flow cut-off actuator interface, an electrical interface, a fluid drainage tube, a drainage tube, and a wearable pressure sensor subassembly. In some aspects of these patient interface components, the wearable pressure sensor subassembly includes, in operable communication, a: (1) a directional sensor, (2) multiple pressure sensors, (3) an integrated flow channel, and (4) a rigid or semi-rigid sensor housing.

[0105] Figure 4 This is a line drawing illustrating a perspective view of a patient interface assembly 50 according to one embodiment of a currently disclosed fluid management system, wherein the patient interface assembly 50 is configured to be removably inserted into and operatively combined with a control system assembly 10. In some embodiments, the fluid drainage tube 60 of the patient interface assembly 50 (primarily comprising a rigid plastic housing such as ABS, nylon, polycarbonate, etc.) can be mounted into a corresponding recess in the control system assembly 10, such as... Figure 1 in the recess 32 depicted.

[0106] like Figure 4 As depicted, the patient interface assembly 50 may include a flow measurement interface 52 (infusion chamber, transparent small container, tube, etc.) for interfacing with the flow measurement detector 28 of the control assembly 10, a flow control actuator interface 56 (flexible tubing, such as silicone, polyurethane, polypropylene-based elastomer, etc.) for interfacing with the clamp 100 of the primary flow control actuator 22 within the control system assembly 10, and a flow cut-off actuator interface 58 (spring-loaded button, stopcock valve, clamp valve, etc.) for interfacing with the secondary flow cut-off actuator 30 of the control assembly 10. The fluid drainage tube 60 may also include a drainage tube 68 (silicone, polyurethane, polypropylene-based elastomer, etc.) connected at its inlet end to a detachable connector 66 (Luer connector, neural connector, etc.) for interfacing with an implanted ventricular catheter, and at its outlet end to a detachable drainage bag 64 (polyethylene, PVC, etc.) for collecting bodily fluids.

[0107] The patient interface assembly 50 may also include a cable 70 between the wearable pressure sensor subassembly 80 and the fluid drainage tube 60, and a set of exposed conductive pads 54 (gold, copper, carbon, silver ink, etc.) on the fluid drainage tube 60 for transmitting electrical signals, data, power, etc., between the patient interface assembly 50 and the control system assembly 10. In such embodiments, a corresponding set of spring contacts (spring pins, battery-type contacts, etc.) in the control system assembly 10 may abut against the conductive pads in the patient interface assembly. Other embodiments of the fluid drainage tube 60 may alternatively include a conventional electrical connector that is manually inserted by the user into a corresponding socket in the control system assembly 10. Other embodiments may completely replace the physical electrical interface by implementing wireless communication (Bluetooth, Wi-Fi, etc.) between the patient interface assembly 50 and the control system assembly 10, or between the patient interface assembly 50 and a remote control system (cloud-based system, on-site or remote server, smartphone, or tablet-based application, etc.). In such arrangements, the wearable pressure sensor subassembly 80 may be powered by a battery or similar power source.

[0108] Figure 5 This is a line drawing depicting one aspect of the patient interface assembly 50 in relation to the patient's anatomy, wherein the proximal end of the drainage tube 68 is detachably connected to the implanted ventricular catheter 206 via a detachable connector 66, and wherein the wearable pressure sensor subassembly 80 is directly attached to the patient's skin substantially close to known anatomical landmarks (EAM, etc.) via sutures 120. In other embodiments, direct fixation of the wearable pressure sensor assembly can be achieved via an adhesive patch (acrylic resin, etc.) with a peel backing or a separate liquid adhesive (cyanoacrylate, etc.) applied between the patient's skin and the wearable pressure sensor assembly housing. Alternatively, patient fixation features can be on a detachable component, such that the wearable pressure sensor assembly is attached (fastened, secured, hook-and-loop fasteners, etc.) to / into a detachable fixation component after being attached (sutured, bonded, etc.) to the patient.

[0109] Figure 6 and Figure 7 Alternative embodiments are depicted in which the wearable pressure sensor subassembly 80 is restrained near the anatomical marker by a wearable device such as a headband or hat (poop cap, helmet, etc.). Such wearable devices may comprise foam, silicone, fabric, hooks and loops, netting, gauze, etc.

[0110] Figure 8 An embodiment of the wearable pressure sensor sub-assembly 80 of the patient interface assembly 50 is depicted (e.g.) Figure 4As depicted, the pressure sensor subassembly 80 includes a sensor array of two or more pressure sensors 126 and 128 for measuring the pressure of a single bodily fluid (ICP, blood pressure, bladder pressure, etc.) and an orientation sensor 122 (accelerometer, tilt sensor, etc.) for detecting the orientation of the flow channel 130. The wearable pressure sensor subassembly 80 may contain (by bonding, mechanical fastening, overmolding, etc.) an integrated flow channel 130 with an inlet and outlet, to which a drainage tube 68 is permanently attached (UV bonded, solvent bonded, epoxy resin, etc.), and one or more suture points 120 for attachment to the patient in close proximity to anatomical markers (EAM, axillary region, etc.). In various embodiments, the sensor array of the wearable pressure sensor subassembly 80 may be constructed on a suitable substrate (polyimide, polyester, FR-4, etc.) according to conventional electronic device manufacturing methods known in the art. In various other embodiments, the sensors are directly mounted onto the housing 132 using various other methods known in the art, such as in-mold printed electronics, conductive inks / epoxy resins, etc. In other aspects, pressure sensors 126 and 128 or orientation sensor 122 may generate digital electrical signals using standard communication protocols known in the art (SPI, I2C, UART, etc.), or may generate analog signals which are converted into digital signals by an analog-to-digital converter.

[0111] In some embodiments, the wearable pressure sensor subassembly 80 may additionally include a contact plate, capacitive switch, or similar sensing element to detect whether the assembly is in contact with the skin. Such features may be useful for detecting certain errors, such as whether the pressure sensor assembly has been dislodged from the patient and may not be reading the correct pressure value.

[0112] Figure 9A and Figure 9B This is a schematic representation of a wearable pressure sensor subassembly 80 according to certain embodiments of the present disclosure, wherein an orientation sensor (A) and a plurality of pressure sensors (P1 and P2) are mounted on a rigid or semi-rigid member (B) at fixed intervals (d). Figure 9A A wearable pressure sensor subassembly 80 is depicted that is horizontally oriented relative to the gravity vector (g). Figure 9B A wearable pressure sensor subassembly 80 is depicted that is vertically oriented relative to the gravity vector (g).

[0113] In some aspects of this embodiment, the orientation sensor detects the orientation of the wearable pressure sensor subassembly 80, thereby facilitating the calculation of the expected pressure difference ΔP according to the following formula: ΔP 预期 = ρ(Δh) Where p is the fluid density (e.g., the density of CSF, saline, blood, urine, etc.), and Δh is the height difference between pressure sensors P2 and P1 relative to the gravity vector.

[0114] like Figure 9A As depicted, when the wearable pressure sensor subassembly 80 is horizontally oriented relative to the gravity vector (g), the pressure readings of the multiple pressure sensors (P1 and P2) are substantially equal because the height difference (Δh) between the two pressure sensors (P1 and P2) is zero (i.e., Δh = 0, therefore ΔP...). 预期 = 0).

[0115] like Figure 9B As depicted, when the wearable pressure sensor subassembly 80 is vertically oriented relative to the gravity vector (g), the pressure difference between the multiple pressure sensors (P1 and P2) is maximized because the height difference (Δh) between the two pressure sensors is also maximized (i.e., Δh = d, therefore ΔP 预期 = ρd).

[0116] In any pressure sensor orientation other than horizontal or vertical, the height difference between multiple pressure sensors (P1 and P2) will vary between 0 and d, based on the vertical component of the pressure sensor orientation relative to the gravity vector (g). The corresponding expected pressure difference will be ΔP. 预期 = 0 to ΔP 预期 = within the range of ρd.

[0117] In some embodiments of the control system algorithm, one or two pressure sensors can be used to determine the actual measured fluid pressure, while the system can use ΔP 预期 (As described above) with ΔP 实际 Any substantial deviation between (obtained directly from pressure sensor readings) is used to detect pressure sensor errors (electrical faults, sensor accuracy deviations, biofouling, etc.).

[0118] It will be apparent to those skilled in the art that this disclosure can be applied to the measurement of gauge pressure or absolute pressure, as either of these can be implemented depending on the type of sensors used for P1 and P2, or by including a separate atmospheric pressure sensor outside the fluid path (such as in a control system component) for calculating gauge pressure.

[0119] The disclosed method provides two layers of redundancy. First, because each pressure sensor in the wearable pressure sensor subassembly 80 is located close to an anatomical marker of the fluid of interest, the second pressure sensor provides a direct “backup” that allows the system to continue operating even if any sensor is determined to be malfunctioning. Second, the system can detect very small deviations in the accuracy of the wearable pressure sensor assembly and take appropriate action (such as notifying the user) before such errors become clinically relevant.

[0120] The disclosed method differs from existing dual-sensor systems, in which one sensor measures the pressure in the target fluid line and the second sensor measures the pressure in a separate reference line, with both pressure sensors positioned elsewhere other than relevant anatomical landmarks (e.g., in a rod-mounted bracket or a hip-worn wearable). In such systems, the true pressure of the target fluid (e.g., true ICP) is calculated as the difference between the pressure in the drainage line and the pressure in the separate reference line.

[0121] The previously described dual-sensor arrangement offers no redundancy and provides limited opportunity for error checking, leaving patients susceptible to sensor misalignment and similar errors. As described in this disclosure, the co-positioning of two pressure sensors and one orientation sensor, substantially close to relevant anatomical landmarks, provides an unprecedented level of measurement accuracy and clinical safety.

[0122] It should be understood that the wearable pressure sensor assembly 80 must be small and lightweight enough to be attached to certain anatomical markers (such as an EAM located on the head) for practical use. Accordingly, using a sufficiently small pressure sensor is crucial for achieving the disclosed embodiments, which are suitable for prolonged contact with bodily fluids and also possess sufficient accuracy and precision for clinical applications. Furthermore, the spacing between the sensors must be small enough to facilitate a suitable overall footprint for the assembly, which further constrains the accuracy of the pressure sensor to achieve useful offset detection as described elsewhere herein. For example, spacing on the order of several centimeters is only useful if the pressure sensor can resolve pressure differences on the order of several millimeters of water (mmH2O). Until recently, such pressure sensors were unknown in the art, making such embodiments impractical. However, due to recent technological advancements in the art, it is now possible to achieve spacing (d) in the range of 1 to 2 cm using tiny (2 to 3 mm wide) pressure sensors with accuracy on the order of ±1 mmH2O, enabling practical embodiments of wearable pressure sensor assemblies with the features described herein to have spacing in the range of 2 to 5 cm. 2 The total area within the specified range.

[0123] 3. Usage and Configuration

[0124] Figure 10 , Figure 11 and Figure 12 Several embodiments of the disclosed body fluid management system are described, which are configured for various clinical use cases.

[0125] Figure 10 An embodiment of a currently disclosed fluid management system is depicted, configured to manage intracranial pressure (ICP) and cerebrospinal fluid (CSF) drainage, wherein a patient interface component 50 is connected proximally to a ventricular catheter via a drainage tube 68 and distally to a drainage collection reservoir 64. Figure 10 The system can be configured via a user-controlled setpoint to activate the main flow rate control actuator 22, thereby allowing CSF drainage when the wearable pressure sensor subassembly 80, attached to an anatomical marker (EAM) near the interventricular orifice, detects that the ICP exceeds the setpoint. Figure 10 The embodiments represented can also be used to manage lumbar spine pressure (by attaching the wearable pressure sensor assembly 80 near an anatomical marker suitable for the application), as well as various other fluids and pressures in various body compartments.

[0126] In other embodiments, the disclosed system may additionally include a peristaltic (or similar) pumping mechanism and connection to a detachable infusion source (infusion bag, infusion bottle, etc.). The pumping mechanism may be configured to perform periodic infusion operations using the infusion source, or to provide continuous or intermittent back pressure for certain monitoring operations. Such embodiments can be used in a variety of clinical applications that benefit from back pressure or periodic flushing. Figure 11 An example of such an arrangement is depicted, wherein the patient interface component 50 is configured to be connected proximally to the indwelling catheter 201 via a bidirectional infusion and drainage tube 69, and distally to the infusion source 203 and the drainage collection reservoir 64. Figure 11 The system can be configured via user-controlled setpoints to activate a pumping mechanism to periodically flush the bladder and catheter with a controlled volume of saline. Alternatively, the system can be configured such that the pumping mechanism infuses saline until a certain upper pressure threshold is detected by a wearable pressure sensor assembly 80 located substantially close to the bladder, at which point the pumping mechanism can be deactivated to allow bladder drainage. In either case, the resulting flushing action mimics the body's natural urinary cycle by minimizing stagnation and low-flow states. Furthermore, repeated cleaning of the area can substantially dilute any bacterial units that begin to colonize. Such an arrangement can be used to reduce the incidence of bladder and urethral infections associated with uncontrolled urinary drainage and prolonged catheterization, which is typically used in current clinical practice to manage patients during intensive care.

[0127] Figure 11 The described embodiments can also be used to monitor pressure in various body cavities for compartment syndrome in a manner with a smaller incision than implanting a pressure transducer directly into a body cavity. For example, in the case of intra-abdominal pressure monitoring, the system controller can utilize an infusion source and pumping mechanism to slightly distend the patient's bladder with a small amount of saline (or similar fluid) and measure the resulting pressure response from the abdominal cavity via a wearable pressure sensor assembly located substantially close to anatomical landmarks of the bladder. Bladder pressure in such an arrangement can serve as a minimally invasive indicator of intra-abdominal pressure. The system control assembly can also be configured to periodically pause intra-abdominal pressure monitoring to allow substantially complete drainage of the bladder, thereby ensuring proper urinary drainage, before re-displacing the bladder to resume intra-abdominal pressure monitoring.

[0128] In other similar embodiments, the patient interface component may be configured to connect to an implanted venous catheter (central line) or an implanted arterial catheter (arterial line), and the control system component may be configured to activate a pumping mechanism to periodically or continuously flush the blood-connecting line with saline. Such arrangements automate and improve clinical practice by ensuring the patency of the artery or central line without continuous clinical monitoring and maintenance, and by ensuring that pressure sensors located within the line are not contaminated by blood components or clotted blood.

[0129] In some embodiments, one or more additional pressure sensors may be placed within the wearable pressure sensor subassembly 80 to increase redundancy, at a second anatomical landmark of interest, on a separate fluid line for measuring multiple fluids (e.g., simultaneously measuring blood and CSF), or at key locations along one or more fluid lines (such as high points on the fluid line where air bubbles are most likely to accumulate). Such an arrangement is necessary in some applications to enhance patient safety, provide additional diagnostic or error checking, and / or add clinical benefit or insight.

[0130] Figure 12Another embodiment of the currently disclosed fluid management system is depicted, wherein the patient interface assembly 50 includes a main fluid line 68 for proximal connection to an implanted ventricular catheter 206 and distal connection to a removable fluid drainage reservoir 64. In other aspects, the patient interface assembly 50 also includes a second fluid line 205 for proximal connection to an implanted arterial catheter 207 and distal connection to an infusion source 203. In other aspects, the patient interface assembly also includes a first wearable pressure sensor assembly 80a and a second wearable pressure sensor assembly 80b, the first wearable pressure sensor assembly 80a being attached to the patient substantially near an anatomical marker (EAM) suitable for monitoring ICP, and the second wearable pressure sensor assembly 80b being attached to the patient substantially near an anatomical marker (such as the fourth left intercostal space) suitable for monitoring blood pressure.

[0131] Each of the first and second wearable pressure sensor assemblies may include orientation sensors, as described elsewhere herein, for monitoring patient movement / posture and error checking pressure sensor readings. Including multiple orientation sensors facilitates more detailed tracking of patient posture (e.g., tracking patient trunk orientation independently of head orientation for more accurate real-time modeling of the spine and associated CSF pressure in 3D space). This information may be used by system control components to automatically adjust the displayed values ​​to more accurately reflect the true values ​​of specific parameters at anatomical points of interest, or to track patient movement over time (e.g., to ensure the patient moves at an adequate frequency to prevent pressure injury, or to monitor patients who may awaken from a coma or sedation).

[0132] In some embodiments, the first wearable pressure sensor assembly may monitor only ICP, while the second wearable pressure sensor assembly may monitor both ICP and blood pressure. This arrangement provides a pressure reference for the ICP, which is normalized at the same height as the blood pressure reference used for accurate calculation of CPP. In an alternative embodiment, the second wearable pressure sensor assembly may monitor only blood pressure.

[0133] In some embodiments, the patient interface component may comprise a single integrated component, while in other embodiments, the primary pipeline, secondary pipeline, and tertiary pipeline, and their associated components, may be separate patient interface components. Figure 11 and Figure 12 The various aspects of the pumping mechanism 202 depicted can be divided between the patient interface assembly 50 and the control system assembly 10. In other embodiments, the system can be configured to independently monitor or control two bodily fluids (e.g., as...). Figure 11 As described, intra-abdominal pressure is monitored via an indwelling urinary catheter connected to the first fluid line, and as... Figure 10The process involves independently monitoring the ICP and providing controlled drainage of CSF on a second fluid line.

[0134] The disclosed fluid management system (such as Figure 12 The described embodiments can also be configured to manage fluid pressure or drainage rate based on derived parameters using data from two combined wearable pressure sensor components. For example, the system can be configured to manage CSF drainage according to a CPP target setpoint and an alarm threshold, where instantaneous CPP is calculated in real time using ICP and MAP values ​​provided by the first and second wearable pressure sensor components, respectively. In other embodiments, the disclosed system can be similarly configured to manage the pressure or drainage rate of other bodily fluids based on other derived parameters (spinal perfusion pressure, abdominal perfusion pressure, etc.). Systems that automatically manage fluid pressure and drainage rate based on derived parameters (e.g., CPP) represent a significant advancement over the prior art and enable exciting and useful clinical applications that would be impossible or impractical with existing technology.

[0135] It should be understood that the disclosed fluid management system can therefore be configured in various ways to monitor or manage various fluid or anatomical subsystems, which may be considered useful in clinical practice without departing from the spirit of this disclosure.

[0136] Therefore, the scope of this disclosure is indicated by the appended claims rather than by the foregoing description, and all variations falling within the meaning and scope of the equivalents of the claims are intended to be included herein.

Claims

1. A body fluid management system, comprising: Control system components and patient interface components, The control system components are configured to monitor blood pressure, body fluid pressure, and perfusion pressure of the body compartment containing the body fluid. The patient interface component includes a first fluid line and a second fluid line. At least one first pressure sensor and at least one second pressure sensor are disposed in the first fluid line and configured to be in communication with the bodily fluid. At least one third pressure sensor is disposed in the second fluid line and configured to be in communication with the blood fluid. The at least one first pressure sensor is configured to be located near a first anatomical marker suitable for monitoring the body fluid pressure. The at least one second pressure sensor and the at least one third pressure sensor are configured to be located together near a second anatomical marker for monitoring blood pressure. The control system component is configured to display pressure values ​​from the at least one first pressure sensor as the body fluid pressure within the body compartment. The control system component is configured to display pressure values ​​from the at least one third pressure sensor as the true pressure of the blood. The control system component is configured to calculate and display the infusion pressure as the difference between the pressure value from the at least one third pressure sensor and the pressure value from the at least one second pressure sensor.

2. The body fluid management system of claim 1, wherein the at least one first pressure sensor is disposed in a first wearable pressure sensor subassembly, the first wearable pressure sensor subassembly further comprising a first orientation sensor and a first housing, configured for attachment to the first anatomical marker. Furthermore, the at least one second pressure sensor and the at least one third pressure sensor are disposed in a second wearable pressure sensor subassembly, the second wearable pressure sensor subassembly also including a second orientation sensor and a second housing, configured for attachment to the second anatomical marker.

3. The body fluid management system according to claim 1, wherein the control system component includes at least one fluid flow detection and control sub-component. The first fluid line is configured to connect at its proximal end to a first catheter inserted into the body compartment and at its distal end to a body fluid drainage reservoir. The second fluid line is configured to be connected at its proximal end to a second catheter in communication with arterial blood flow, and at its distal end to an infusion source.

4. The body fluid management system according to claim 3, wherein the at least one fluid flow detection and control sub-component includes a first fluid flow detection and control sub-component and a second fluid flow detection and control sub-component. The first fluid flow detection and control sub-component is configured to detect and control the flow of the body fluid. The second fluid flow detection and control sub-component is configured to control the flow of the infusion fluid. Furthermore, the control system component is configured to calculate the capacity within a user-selected time interval.

5. The body fluid management system of claim 4, wherein the first fluid flow detection and control sub-component includes a valve configured to allow or prevent the body fluid from flowing from the first conduit to the body fluid drainage reservoir, and wherein the second fluid flow detection and control sub-component includes a pump configured to pump the infusion fluid from the infusion source through the second fluid line and the second conduit.

6. The body fluid management system of claim 1, wherein the control system component includes a graphical user interface configured to display at least one pressure waveform.

7. The body fluid management system according to claim 1, wherein the perfusion pressure is cerebral perfusion pressure, the body compartment is cranial cavity, the body fluid is cerebrospinal fluid, the body fluid pressure is intracranial pressure, and the blood pressure is arterial blood pressure.

8. The body fluid management system according to claim 1, wherein the perfusion pressure is the spinal cord perfusion pressure, the body compartment is the spinal canal, the body fluid is cerebrospinal fluid, and the body fluid pressure is lumbar spine pressure.

9. The body fluid management system of claim 4, wherein the control system component is configured to control the drainage of the body fluid according to user-selected parameters.

10. The body fluid management system of claim 9, wherein one of the user-selected parameters is a target perfusion pressure.

11. The body fluid management system of claim 9, wherein one of the user-selected parameters is the target intracranial pressure.

12. The body fluid management system according to claim 9, wherein one of the user-selected parameters is the target body fluid drainage volume.

13. The body fluid management system of claim 1, wherein the control system component is configured to issue an alarm based on one or more user-defined thresholds of perfusion pressure, body fluid drainage volume, body fluid pressure, blood pressure, or pressure waveform.

14. The body fluid management system according to claim 2, wherein the at least one first pressure sensor comprises a plurality of first pressure sensors spaced at a fixed distance from each other. The plurality of first pressure sensors and the first orientation sensor are configured on a rigid member to detect the offset of the plurality of first pressure sensors based on the difference between the expected differential pressure between the plurality of first pressure sensors and the actual differential pressure between the plurality of first pressure sensors.

15. The body fluid management system according to claim 2, wherein one or both of the second pressure sensor or the third pressure sensor comprises a plurality of pressure sensors spaced at fixed distances from each other. The plurality of second or third pressure sensors and the second orientation sensor are configured on a rigid member to detect the offset of the plurality of second or third pressure sensors based on the difference between the expected differential pressure between the plurality of second or third pressure sensors and the actual differential pressure between the plurality of second or third pressure sensors.

16. The body fluid management system of claim 4, wherein the first fluid line is configured for bidirectional flow, and wherein the distal end of the first fluid line is further configured for connection to a second infusion source.

17. The body fluid management system of claim 16, wherein the at least one fluid flow detection and control sub-component further comprises a third fluid flow detection and control sub-component for detecting and controlling the flow from the second infusion source into the first fluid line.

18. The body fluid management system according to claim 17, wherein the perfusion pressure is the abdominal perfusion pressure, the body compartment is the abdominal cavity, the body fluid is urine, and the body fluid pressure is intra-abdominal pressure.

19. The body fluid management system according to claim 4, wherein one of the capacities is the body fluid drainage volume. Furthermore, the fluid drainage volume mentioned therein is the net volume calculated as the difference between the detected drainage volume and the detected infusion volume.

20. The body fluid management system of claim 2, wherein the first orientation sensor is configured to detect the orientation of a body compartment containing the body fluid. And the second orientation sensor is configured to detect the orientation of the body compartment containing the blood pressure.

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