WO2022009222A1

WO2022009222A1 - System and method of measuring urinary oxygen tension

Info

Publication number: WO2022009222A1
Application number: PCT/IN2021/050654
Authority: WO
Inventors: Dilip SHANKAR; Shankar RAMAIAH
Original assignee: Shankar Dilip
Priority date: 2020-07-05
Filing date: 2021-07-05
Publication date: 2022-01-13

Abstract

A system (100) for monitoring acute kidney injury including a device (125) connected to a catheter tube (115) for assessing health parameters from a biological sample. A probe (130) of an optical sensor inserted in a first port (125a) of the device (125). A spectrophotometer (135b) operatively coupled to the probe (130) configured to measure biological sample based parameter.

Description

TITLE OF THE INVENTION: System and Method of Measuring Urinary Oxygen Tension PREAMBLE OF THE DESCRIPTION : The following complete specification particularly describes the invention and the manner in which it is performed. TECHNICAL FIELD

The present embodiment relates to the field of medical devices. In particular, systems and methods for early detection of kidney malfunction in patients based on real-time monitoring and diagnostics of urinary parameters from a catheterized patient.

BACKGROUND OF THE INVENTION

Urinary catheters, such as Foley Catheters, are frequently used for patients with bladder dysfunction or for patients undergoing surgical procedures. The catheters attached to the patients are provided with diagnostic devices and systems that adopt various methods to monitor and record urinary parameters. The urinary parameters could be one or more of temperature, pH, oxygen tension, conductance, color, specific gravity, turbidity, and the like.

The urinary oxygen tension (P02), also referred to as urinary partial pressure of oxygen, is among the early physiological biomarkers of the risk of acute kidney injury (AKI) in intraoperative and postoperative patient care. Low urinary oxygen tension appears to be an indicator of presence of AKI and there currently are limited biomarkers with predictive value on early detection of AKI. Hence, there is a need for a method and a system that can automatically and accurately monitor in real-time the urinary oxygen tension and generate alert signals against threshold breach of the urinary oxygen tension values for actionable intervention.

The present invention overcomes the problems of the prior art by providing a system and means for real-time monitoring of the urinary oxygen tension values in the urine of a catheterized patient. The urinary oxygen tension values correlate with acute kidney injury (AKI) and stage of the AKI. SUMMARY OF THE INVENTION

In view of the foregoing, a system (100) for monitoring acute kidney injury includes a device (125) connected to a catheter tube (115) for assessing health parameters from a biological sample. A probe (130) of an optical sensor inserted in a first port (125a) of the device (125). A spectrophotometer (135b) operatively coupled to the probe (130) configured to measure biological sample-based parameter. The biological sample is urine and the biological sample-based parameter is dissolved oxygen or oxygen tension. A human machine interface station (135) is connected to a second port (125b) of the device (125) by the catheter tube (115) configured to alert an authorized person by an alerting indicator (135a) of the human machine interface station (135) on breach of a pre-determined threshold value of the oxygen tension of the urine sample. The device (125) incorporates a galvanic dissolved oxygen sensor or polaro graphic dissolved oxygen sensor.

The sensor operatively coupled to the device (125) is configured to measure pH, specific gravity and glucose parameters of the biological sample.

The sensor is a pH sensor, a radiometric sensor, a specific gravity sensor, a glucose sensor, a ketone sensor, and a nitrate sensor.

The human machine interface (135) is configured to control a vacuum pump installed in the urine clearance line of the catheter tube (115).

The human machine interface (135) is connected to an operator (220) by a communication interface (210a). The human machine interface (135) communicates with a gateway (230) by a communication interface (210b).

The gateway (230) communicates with a data storage module (240) by a communication interface (210c).

The human machine interface (135) further comprises a pair of ultrasonic transducer (255, 250) to monitor the parameters such as urine density.

In an aspect, a dissolved oxygen measuring instrument in a urine sample is disclosed. The oxygen measuring instrument comprising an LED and an oxygen sensitive spot exposed to the urine sample. The LED is configured to emit a pulse of blue light with a first intensity to irradiate the oxygen sensitive spot. The oxygen sensitive spot is configured to emit a pulse of red light with second intensity upon reaction with the pulse of light with first intensity. The intensity of the pulse of red light is indicative (or proportional) to dissolved oxygen in the urine sample. The presence of oxygen in the urine sample contacts the coating and the intensity of emitted light that is red light is changed. The more oxygen molecules come in contact with the coating, the lower the intensity and the shorter the duration of the red radiation. These changes in the profile curve are used to determine the measurement. The sensing element (lumiphore) is activated, or excited when illuminated with a blue light. When activated, the lumiphore then emits blue light in an intensity that is inversely proportional to the amount of oxygen present. The sensor cap contains a luminescent dye, which glows red when exposed to blue light. Oxygen interferes with the luminescent properties of the dye, an effect called “quenching.” A photodiode compares the “quenched” luminescence to a reference reading, allowing the calculation of dissolved oxygen concentration.

In an embodiment, the dissolved oxygen measuring instrument is operatively coupled anywhere in a urine clearance line of a foley catheter. In an embodiment, the dissolved oxygen measuring instrument is placed inside a urine bag/pouch of a catheter urine system (100).

In another aspect a method (500) for monitoring urinary oxygen tension includes receiving (510) of urine sample for measurement of oxygen sensitive luminophores then illuminating (520) said received urine sample (510) with an illuminating light source using a first branch of an optic fiber. Receiving (530) luminescence from said oxygen sensitive luminophores in contact with said urine sample through a second branch of said optic fiber by measurement module of a spectrometer (135b) and estimating (540) lifetime of said oxygen sensitive luminophores by a processing module of said spectrometer (135b). Further, estimating (550) urine oxygen tension from estimated lifetime of said oxygen sensitive luminophores by said processing module of said spectrometer (135b) and generating (560) a risk score by evaluating said urinary oxygen tension and alerts a concerned clinical personnel.

The spectrometer (135b) is configured to control a vacuum pump installed in the urine clearance line of the catheter tube (115).

BRIEF DESCRIPTION OF DRAWINGS

The accompanying drawings are included to provide a further understanding of the present invention and are incorporated in and constitute a part of this specification. Embodiments of the present invention will be described in greater detail below based on the exemplary figures and, together with the description, serve to explain the principles of the present invention.

The figures are not drawn to scale and the proportions of certain parts have been exaggerated for convenience of illustration. Further, in the accompanying drawings and description that follow, like parts are indicated throughout the drawings and written description with the same reference numerals, wherein:

Figure 1 shows an embodiment of a Foley catheter urine system comprising a human machine interface (HMI) station that accommodates a drainage urine bag in accordance with an exemplary embodiment of the present invention;

Figure 2 shows a block diagram of a system for a human-machine interface (HMI) station and its communicatively coupled devices in accordance with an exemplary embodiment of the present invention;

Figure 3 shows a block diagram representing some aspects of the communication between the HMI station and various modules such as the diagnostic, communication, and visualization modules in accordance with an exemplary embodiment of the present invention;

Figure 4 is a diagrammatic illustration of urinary oxygen tension monitoring system in accordance with an exemplary embodiment of the present invention; and Figure 5 is a flowchart of a method for estimating the urinary oxygen tension in accordance with an exemplary embodiment of the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

As will be described in detail hereinafter, with reference to the accompanying drawings in which exemplary embodiments are shown, techniques for estimating the urinary oxygen tension from the estimated lifetime of the oxygen- sensitive luminophores are presented. These exemplary embodiments are provided only for illustrative purposes and so that this disclosure will be through and complete and will fully convey the scope of the invention to those of ordinary skill in the art. The invention disclosed may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Various modifications will be readily apparent to persons skilled in the art. The general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the invention. Moreover, all statements herein reciting embodiments of the invention, as well as specific examples thereof, are intended to encompass both structural and functional equivalents thereof.

The term tip and catheter tip are interchangeably used in the context.

The term spectrophotometer and spectrometer are interchangeably used in the context.

The term oxygen tension and dissolved oxygen are interchangeably used in the context.

Figure 1 shows an embodiment of a Foley catheter urine system comprising a human machine interface (HMI) station that accommodates a drainage urine bag in accordance with an exemplary embodiment of the present invention.

The Foley catheter urine system 100 is provided with a tip 105 that may be inserted into a patient's bladder to facilitate drainage of urine collected in the bladder. A small retention balloon 110 is provided close to the catheter tip 105 wherein the retention balloon 110 is inflated with a fluid (typically sterile water) to prevent the catheter from sliding out of the bladder. The retention balloon 110 is deflated when the catheter needs to be removed. The urine collected by the catheter tip 105 flows down along a hollow, flexible catheter tube 115 to eventually be collected in a drainage urine bag 150. The Foley catheter urine system 100 is adapted as a multi-lumen 120 catheter and may have two-lumens 120a, 120b wherein one of the lumens, the first lumen 120a (also referred to as balloon inflation lumen) has a valve on the outside end and connects to the retention balloon 110 near the catheter tip 105. This balloon inflation lumen 120a is configured for inflating or deflating the retention balloon 110. The other lumen, the second lumen 120b (also referred to as fluid drainage lumen) is open at both ends and allows for urine drainage from the urinary bladder by connection to a drainage urine bag 150 through further use of catheter tube 115 as may be necessary. In a preferred embodiment of the invention, the traditional catheter system could be engineered to enable attaching a device 125 to the catheter for incorporating array of diagnostic and control tools that may not already be part of the traditional Foley catheter urine system 100. The first channel or port 125a of the device 125 is adapted for including a fiber-optic probe 130 of an optical dissolved oxygen sensor that supplements a spectrophotometer 135b (also called a spectrometer) provided for making an optics based measurements of urine parameters such as oxygen tension, specific gravity, and the like. Further details on the fiber-optic probe 130 are provided with reference to the description in FIG.4. The second port 125b of the present device 125 is open at both ends and allows for urine drainage from the urinary bladder by connection to a drainage urine bag 150 through further use of the catheter tube 115 as may be necessary.

In an embodiment, the device 125 may include a galvanic dissolved oxygen sensor to monitor the dissolved oxygen in real time. In an embodiment, the galvanic dissolved oxygen sensor is an electrochemical sensor to monitor the dissolved oxygen. In an embodiment, the galvanic sensor undergoes chemical reduction reaction and generates electrical signals. In an embodiment, the electrical signals are recorded by a dissolved oxygen instrument.

In an embodiment, the device 125 may include a polarographic dissolved oxygen sensor to monitor the dissolved oxygen in real time. In an embodiment, the polarographic dissolved oxygen sensor is an electrochemical sensor to monitor the dissolved oxygen. In an embodiment, the polarographic sensor undergoes chemical reduction reaction and generates electrical signals. In an embodiment, the electrical signals are recorded by a dissolved oxygen instrument.

In an embodiment, the device 125 may include a specific gravity sensor to monitor the specific gravity of the biological sample. In an embodiment, the specific gravity sensor triggers the concerned authorities once it reaches above or below the predetermined range. In an embodiment, the predetermined range is between 1.005 and 1.025.

In an embodiment, the device 125 may include a radiometric sensor for monitoring the density of the biological sample. In an embodiment, the device 125 includes a density sensor to monitor the density of the biological sample.

In an embodiment, the device 125 may include a glucose sensor to monitor the level or glucose in the biological sample in real time.

In an embodiment, the device 125 may include a ketone sensor to monitor the presence of ketones in the biological sample. In an embodiment, ketone includes acetone, aceto acetic acid or B- hydroxyl butyric acid.

In an embodiment, the device 125 may include a nitrate sensor to monitor the presence of nitrates in the sensor. In an embodiment, the nitrate sensor detects the nitrates presence and alerts the concerned authorities about the chances of urinary tract infection. In an embodiment, urinary tract infection includes the infection caused by bacteria. In an embodiment, the bacteria includes E. coli, Klebsiella, Proteus, Enterobacter, Citrobacter, or Pseudomonas. In a preferred embodiment of the invention, the Foley catheter urine system 100 may include a human-machine interface (HMI) station 135 that is configured with features comprising of data logging, display, and alert generation. The HMI station 135 could is adapted to provide control of diagnostic and control devices such as vacuum pumps installed in the urine clearance line of the catheter tube (115), urine sample analysis devices, spectrophotometers, motorized mechanisms for urine extraction from the drainage urine bag, urine density measurement apparatus, and the like. Furthermore, the HMI station 135 is provided with storage, processing, and communication capabilities and is further elaborated upon in the discussion with reference to FIG. 2.

With reference now to FIG. 2, the HMI station 135 is provided with storage, processing, and communication capabilities to enable it to store the data corresponding to the urinary parameters measured by the array of diagnostic devices mentioned above. These diagnostics devices are communicatively connected with the HMI station 135 to enable such a data transfer from the diagnostic devices to the HMI station 135.

In a preferred embodiment, the HMI station 135 is further configured to display a graphical and textual visualization of pre-defined urinary parameters such as pH, specific gravity, conductivity etc. The HMI station 135 generates alarm through the provided alerting units 135a, when the measured oxygen tension value breaches the predetermined threshold or standard value of the oxygen tension of a normal human being with normal kidney functioning. The alarms could be audible and / or visual signal that draws the attention of a clinical personnel towards one or more urinary parameters that may be breaching a clinically pre-defined acceptable range.

In an embodiment, the device may include a pH sensor for monitoring the renal conditions in real time. In an embodiment, the catheter tube 115 is attached with a pH sensor to monitor the acidity level in the biological sample in real time. In an embodiment, the specific gravity sensor triggers the concerned authorities once it reaches above or below the predetermined range. In an embodiment, the HMI station 135 is configured to have an operator 220 such as clinical personnel for manually interfacing with the HMI station 135 for reading, writing and / or performing other administrator related tasks. The read task could involve the operator 220 or an authorized clinical personnel downloading data from the HMI station 135 to another external device that is capable of being interfaced with the HMI station 135. Such external device could be a local storage or computational device including a local server, data card, a local computer. The write task could involve updating key information such as re-defining acceptable range for diagnostic parameters, adding physician notes on the device, editing the list of parameters for graphical visualization, and the like.

In an embodiment, the HMI station 135 may be communicatively connected through a gateway 230 with an external server 240 such as cloud computing and storage server and/or an edge computing and storage server. The external server 240 may additionally be configured to have storage, computational processing, and visualization capabilities. The storage capability could be used for storing and archiving patient information in the form of electronic medical records (EMRs). All the communication interfaces 210a, 210b, 210c may be provided through wired or wireless communication technologies using different communication protocols (such as TCP/IP). The external server could also host software tools for performing computational processing on the saved and archived data. The computational processing could comprise of time-series analysis and anomaly detection, implementing machine learning algorithms to extract trends in data that could help detection of patient conditions such as urinary tract infection (UTI), and urinary composition recognition using AI camera modules and other diagnostic data. Thus the computationally processed data also be visualized with the visualization features provided on the external server 240.

Additionally (not shown in the figure), the external server 240 is communicatively connected with a plurality of authorized processing devices such as smart phones, laptops, etc, belonging to the patient or other clinical personnel, either through a web interface or through an application program (app).

In an embodiment, the external server allows the patients and other clinical personnel to access the medical records with ease. In an embodiment, the external server allows the clinical personnel to collaborate across geographical regions for improved data assessment and clinical prognostics.

The diagnostic devices could optionally comprise of a urine density monitoring system 245 wherein the urine density or specific gravity is estimated using known techniques such as ultrasonic resonance interferometry. In such a device, the urine sample within the urine density measurement device 245 is interrogated using an ultrasonic transducer 255 that is coupled with the urine density monitoring system 245 using an acoustic coupler (not shown). In this well-known technique, a second ultrasonic transducer 250 is used to estimate the parameters of the acoustic wave transmitted by the first ultrasonic transducer 255 through the urine sample within the urine density measurement device 245.

The parameters of the acoustic wave may comprise of (acoustic wave) frequency- dependent energy attenuation, speed of the acoustic wave propagation, and the time taken by the acoustic wave to transmit across the urine density measurement device 245. The urine density measurement device 245 also includes signal generator devices, signal measurement devices, and signal processing units (not shown) that can either be standalone or communicatively and electrically coupled with the HMI station 135.

FIG. 3 shows a block diagram representing aspects of the communication between the HMI station 135 and various modules and devices including one or more diagnostic devices such as the urinary oxygen tension measurement device 330, visualization and alerting unit 320, a data transmission system 350, a battery management system 340, and an application program interface (API) module 360. In a preferred embodiment of the invention, the HMI station 135 is provided with a microcontroller 310 that is central to communication between the HMI station 135 and the above mentioned various modules and devices.

The microcontroller 310 of the HMI station 135 may be connected with the mentioned various modules and devices using a communication bus or data bus such as a CAN bus that is commonly used in many microcontroller based communications. Data from the mentioned various modules and devices is transferred to the HMI station 135 through this communication bus.

The urinary oxygen tension monitoring system 330 measures the partial pressure of dissolved oxygen (D02) in a sample of urine. The microcontroller 310 of the HMI station 135 is connected with the urinary oxygen tension monitoring system 330 using a communication bus or data bus such as a CAN bus that is commonly used in many microcontroller based communications. Data, such as time-series values of urinary oxygen partial pressure, from the urinary oxygen tension monitoring system 330 is transferred to the HMI station 135 through this communication bus. Further details on the urinary oxygen tension monitoring system 330 will be discussed in reference with FIG. 4.

The HMI station 135 could be a portable, standalone unit with its own battery module and associated battery management system 340 to power the HMI station 135. The microcontroller 310 of the HMI station 135 may be connected with the battery management system 340 using a communication bus or data bus such as a CAN bus that is commonly used in many microcontroller based communications. Data from the battery management system 340 is transferred to the HMI station 135 through this communication bus. This data may include commands for controlling the battery module, state of health of the battery module, charging status of the battery module, and remaining useful life of the battery module.

The microcontroller 310 on the HMI station 135 also interfaces with communication modules such as the data transmission system 350. The data transmission system 350 facilitates connecting the HMI station 135 with external servers 240 and operators 220. The microcontroller 310 of the HMI station 135 may be connected with the data transmission system 350 using a communication bus or data bus such as a CAN bus that is commonly used in many microcontroller based communications. Data between the data transmission system 350 is exchanged through this communication bus. This data may include commands for authorized access and validating external computational devices that seek to communicate with the HMI station 135.

The microcontroller 310 on the HMI station 135 also interfaces with application program interface (API) modules 360, wherein the API module 360 provides the necessary APP interface to the HMI station 135 and integration to EMRs. The API module 360 also hosts alerting system with risk assessment for different diseases. The visualization and alerting unit 320 (also referred to herein as the ON monitoring system alerting system) on the HMI station 135 provides graphical and textual display of measured urinary parameters as well as estimated patient condition. The list of displayed parameters could be edited by an authorized clinical personnel to include such parameters and conditions as hydration status, urine output, AKI stage, episodes of oliguria, and hypovolemia. The alerting indicator 135a on the HMI station 135 could be a visual and/or auditory signal. It alerts the clinical personnel if any of the parameters breach a pre-defined threshold or/and a patient condition is estimated that requires immediate medical intervention. As is seen in FIG. 3, the microcontroller 310 is connected with the visualization and alerting unit 320 through a communication bus or data bus such as a CAN bus that is commonly used in many microcontroller based communications.

It should be apparent to those skilled in the art that many more modifications besides those already described are possible without departing from the inventive concepts herein.

FIG. 4 shows a diagrammatic illustration of the urinary oxygen tension monitoring system 400 in accordance with an exemplary embodiment of the present invention. The urinary oxygen tension monitoring system 400 is provided with a two-branched optical fiber 430. A first branch 430a of the optical fiber 430 is used to guide optical energy (light) to the tip 430c (also referred to herein as a sensor tip) of the optical fiber 430. A second branch 430b of the optical fiber 430 is used to guide the light collected from the sensor tip 430c of the optical fiber 430. The sensor tip 430c of the optical fiber 430 is immersed in the urine sample of which the oxygen tension is to be measured. The sensor tip 430c of the fiber is further provided with an oxygen sensitive luminophore the lifetime of the luminescence of which is dependent on the local oxygen concentration. When optical energy coming in from the first branch 430a of the optical fiber 430 and interacts with the oxygen sensitive luminophore at the sensor tip 430c, the oxygen sensitive luminophores start to emit light (luminescence). A fraction of this emitted luminescence is gathered and directed towards a spectrometer 440 using the second branch 430b of the optical fiber 430.

The spectrometer 440 of the urinary oxygen tension monitoring system 400 is provided with a measurement module 440a, a processing module 440b, a storage module 440c, and a communication module 440d. The measurement module 440a of the spectrometer 440 facilitates measuring the light intensity as a function of wavelength and time. This data pertaining to the light intensity is saved and archived by the storage module 440c of the spectrometer 440. The storage module 440c also holds other data such as calibration curves of the urinary oxygen tension monitoring system 400 obtained using well known techniques. The storage module 440c further holds software methods for estimating oxygen concentration values using measured values of oxygen tension.

The processing module 440b of the spectrometer 440 facilitates processing capabilities to estimate the lifetime of the oxygen sensitive luminophores using the light intensity data. The processing module 440b further facilitates implementing of various software methods such as estimating oxygen concentration values that are stored on the storage module 440c of the spectrometer 440.

The communication module 440d of the spectrometer 440 facilitates communication between the spectrometer 440 and other devices such as the HMI station 135, the operator 220, and the external server 240. The communication may be facilitated through wired or / and wireless communication technologies using different communication protocols (such as TCP/IP).

The light source 410 provided with the oxygen tension monitoring system 400 could be either a pulsed light source or / and a continuous light source the intensity of which could be modulated. The pulsed light source 410 could be used for time-domain measurements of the oxygen sensitive luminophore lifetime measurements. The continuous light source 410 could be used for a frequency- domain measurement of the oxygen sensitive luminophore lifetime measurements. The light source 410 may further be a monochromatic light source or a broad band of wavelengths such a white light continuum.

In one embodiment of the invention, the spectrometer 440 is a standalone unit. In another embodiment of the invention, the spectrometer 440 is part of the HMI station 135. In one embodiment of the invention, the urinary oxygen tension monitoring system 400 is coupled with the device 125 of FIG. 1 wherein the spectrometer 440 is situated at 135b in FIG.l and the optical fiber 430 is coupled to the first port 125a of the device 125. In this embodiment of the invention, the sensor tip 430c of the optical fiber 430 may be placed in one or more of the three ways: a) Between Foleys catheter and the drainage urine bag 150. b) The sensor tip 430c may be placed proximal to the tip 105 of Foleys catheter by deep insertion of the optical fiber 430 inside the device 125 along the first port 125a of the device 125. c) The sensor tip 430c of the optical fiber 430 may be placed inside the drainage urine bag 150 by inserting the optical fiber 430 inside the device 125 to monitor oxygen tension values of urine sample in the drainage urine bag 150.

The above described system and method for oxygen tension monitoring can measure the oxygen partial pressure in the range of sub lmmHg to over 500 mmHg. Furthermore, the oxygen tension measurements and made and reported in real-time for minute to minute to hourly readings as may be set within the HMI station 135 or the spectrometer 440 configuration. The data such as the time-series data corresponding to the oxygen tension measurement is stored in storage module 440c of the spectrometer 440. The storage module 440c could be one or more of a hard disk drive, a solid state drive, a flash drive, and the like. Data from the storage module 440c may be transferred to a cloud server or / and yet another computing device over an API using a wired or a wireless communication technology using different communication protocols (such as TCP/IP). In an aspect, a dissolved oxygen measuring instrument in a urine sample is disclosed. The oxygen measuring instrument comprising an LED and an oxygen sensitive spot exposed to the urine sample. The LED is configured to emit a pulse of blue light with a first intensity to irradiate the oxygen sensitive spot. The oxygen sensitive spot is configured to emit a pulse of red light with second intensity upon reaction with the pulse of light with first intensity. The intensity of the pulse of red light is indicative (or proportional) to dissolved oxygen in the urine sample. The presence of oxygen in the urine sample contacts the coating and the intensity of emitted light that is red light is changed. The more oxygen molecules come in contact with the coating, the lower the intensity and the shorter the duration of the red radiation. These changes in the profile curve are used to determine the measurement. The sensing element (lumiphore) is activated, or excited when illuminated with a blue light. When activated, the lumiphore then emits blue light in an intensity that is inversely proportional to the amount of oxygen present. The sensor cap contains a luminescent dye, which glows red when exposed to blue light. Oxygen interferes with the luminescent properties of the dye, an effect called “quenching.” A photodiode compares the “quenched” luminescence to a reference reading, allowing the calculation of dissolved oxygen concentration.

In an embodiment, the dissolved oxygen measuring instrument is operatively coupled anywhere in a urine clearance line of a foley catheter. In an embodiment, the dissolved oxygen measuring instrument as claimed in claim 1, wherein the instrument is placed inside a urine bag/pouch of a catheter urine system (100).

Figure 5 is a flowchart of a method for estimating the urinary oxygen tension in accordance with an exemplary embodiment of the present invention.

The step 510 comprises receiving, by the sensor tip 430c, a urine sample from the Foleys catheter system, to estimate the urinary oxygen tension through measurement of the lifetime of oxygen sensitive luminophores provided at the sensor tip 430c of the optical fiber 430. As described above, the sensor tip 430c is provided with an oxygen sensitive luminophores the luminescence lifetime of which is dependent on the local oxygen concentration or oxygen tension or oxygen partial pressure.

The step 520 comprises illuminating the received urine sample at the sensor tip 430c with the illuminating light source 410 using a first branch 430a of the optical fiber 430. The illuminating light source 410 provides the optical energy required to optically excite the oxygen sensitive luminophores provided at the sensor tip 430c of the optical fiber 430. The excited state lifetime of the oxygen sensitive luminophores are dependent on the local oxygen concentration within the urine sample received by the sensor tip 430c of the optical fiber 430. Depending on the type of lifetime measurement (time-domain or frequency domain), the light source 410 may be a pulsed light source or a continuous light source the intensity of which could be modulated.

The step 530 comprises receiving, by the measurement module 440a of the spectrometer 440, luminescence from the oxygen sensitive luminophores that are in contact with the received urine sample. This luminescence is received by the measurement module 440a of the spectrometer 440 through a second branch of the optical fiber 430b.

The step 540 comprises estimating the lifetime of the oxygen sensitive luminophores by the processing module 440b of the spectrometer 440. Estimating the lifetime information involves performing various data processing on the luminescence time-series data as obtained in step 530. The data processing here may involve the well know processes such as baseline correction of luminescence time-series data, mathematical fitting of the luminescence time-series data, and deconvolution of the pulsed light source from the luminescence time-series data.

The step 550 comprises estimating the urinary oxygen tension from the estimated lifetime of the oxygen sensitive luminophores by the processing module 440b of the spectrometer 440. This may be done through comparison of the estimated lifetime of the oxygen sensitive luminophores with a calibration curve that is saved within the storage module 440a of the spectrometer 440.

The step 560 comprises generating a risk score for early detection of acute kidney injury (AKI) and staging of the AKI based on the evaluated urinary oxygen tension and dispatch actionable alert signal for clinical personnel. The alert signals can be visual, textual, and / or auditory as was mentioned earlier. The alert signals notifications may correspond to AKI staging, minute to minute or hourly notifications of the urinary oxygen tension, and the like. Once notifications are alerted, the clinical personnel can take necessary actions. The alert notifications may be customized as per the needs of the clinical personnel for a minute to minute communication facilitating close monitoring or hourly monitoring of the urinay oxygen tension and AKI staging.

While the foregoing describes various embodiments of the invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof. The invention is not limited to the described embodiments, versions or examples, which are included to enable a person having ordinary skill in the art to make and use the invention when combined with information and knowledge available to the person having ordinary skill in the art.

Claims

I/We Claim:

1. A system (100) for monitoring acute kidney injury comprising: a device (125) connected to a catheter tube (115) for assessing health parameters from a biological sample; a probe (130) of an optical sensor inserted in a first port (125a) of the device (125); a spectrophotometer (135b) operatively coupled to the probe (130) configured to measure biological sample based parameter.

2. The system (100) as claimed in claim 1, wherein the biological sample is urine and the biological sample based parameter is dissolved oxygen or oxygen tension.

3. The system (100) as claimed in claim 1, wherein a human machine interface station (135) is connected to a second port (125b) of the device (125) by the catheter tube (115) configured to alert an authorized person by an alerting indicator (135a) of the human machine interface station (135) on breach of a pre-determined threshold value of the oxygen tension of the urine sample.

4. The system (100) as claimed in claim 1, wherein the device (125) incorporates a galvanic dissolved oxygen sensor or polarographic dissolved oxygen sensor.

5. The system (100) as claimed in claim 1, wherein the sensor operatively coupled to the device (125) is configured to measure pH, specific gravity and glucose parameters of the biological sample.

6. The system (100) as claimed in claim 1, wherein the sensor is a pH sensor, a radiometric sensor, a specific gravity sensor, a glucose sensor, a ketone sensor, and a nitrate sensor.

7. The system (100) as claimed in claim 1, wherein the human machine interface (135) is configured to control a vacuum pump installed in the urine clearance line of the catheter tube (115).

8. The system (100) as claimed in claim 1, wherein the human machine interface (135) is connected to an operator (220) by a communication interface (210a).

9. The system (100) as claimed in claim 1, wherein the human machine interface (135) communicates with a gateway (230) by a communication interface (210b).

10. The system (100) as claimed in claim 1, wherein the gateway (230) communicates with a data storage module (240) by a communication interface (210c).

11. The system (100) as claimed in claim 1, wherein the human machine interface (135) further comprises a pair of ultrasonic transducer (255, 250) to monitor the parameters such as urine density.

12. A dissolved oxygen measuring instrument in a urine sample comprising; an LED, and an oxygen sensitive spot exposed to the urine sample; the LED is configured to emit a pulse of light with a first intensity to irradiate the oxygen sensitive spot; the oxygen sensitive spot is configured to emit a pulse of light with second intensity upon reaction with the pulse of light with first intensity; wherein the pulse of light with second intensity is indicative (or proportional) to dissolved oxygen in the urine sample.

13. The dissolved oxygen measuring instrument as claimed in claim 1, wherein the instrument further comprising a photodiode for comparing quenched luminescence dye to a predetermined value to measure the dissolved oxygen.

14. The dissolved oxygen measuring instrument as claimed in claim 1, wherein the instrument is operatively coupled anywhere in a urine clearance line of a foley catheter.

15. The dissolved oxygen measuring instrument as claimed in claim 1, wherein the instrument is placed inside a urine bag/pouch of a catheter urine system (100).

16. A method (500) for monitoring urinary oxygen tension comprising: receiving (510) urine sample for measurement of oxygen sensitive luminophores; illuminating (520) said received urine sample (510) with an illuminating light source using a first branch of an optic fiber; receiving (530) luminescence from said oxygen sensitive luminophores in contact with said urine sample through a second branch of said optic fiber by measurement module of a spectrometer (135b); estimating (540) lifetime of said oxygen sensitive luminophores by a processing module of said spectrometer (135b); estimating (550) urine oxygen tension from estimated lifetime of said oxygen sensitive luminophores by said processing module of said spectrometer (135b); and generating (560) a risk score by evaluating said urinary oxygen tension and alerts a concerned clinical personnel.

17. The method as claimed in claim 16, wherein the spectrometer (135b) is configured to control a vacuum pump installed in the urine clearance line of the catheter tube (115). Dated this 05^th Day of July, 2021

Signature of Patent Agent:

(Rahul Bagga) IN/PA-2366