Patent Application
20190090859
This application relates generally to techniques for analyzing urine samples. The application also relates to components, devices, systems, and methods pertaining to such techniques.
Various embodiments of the application are directed to a system that includes a capturing arrangement configured to receive urine from a user. The capturing arrangement may be used in conjunction with a toilet, urinal, bladder catheter, or any other such device configured to capture urine from a user. The system includes a chamber fluidically coupled to the capturing arrangement. A diverter is fluidically coupled between the capturing arrangement and the chamber. The diverter is configured to divert a volume of the received urine to the chamber. For example, the volume may be a volume of urine captured in the initial stream of urine, captured in mid-stream, or captured in the finishing stream of urine. A detection unit is configured to sense for presence of a predetermined characteristic in the volume of the urine and to generate at least one electrical signal comprising information about the predetermined characteristic. The system may include a communication device, such as a wireless transceiver, which facilitates transmission of detection data to a remote system or device. According to various embodiments, the system is adapted for mounting near, in, or on a toilet or urinal. In some embodiments, the system may be mounted on a toilet seat, for example. In some embodiments, the chamber containing the urine is detachable from the system and configured for transport to a remote location for assessment by a remotely located detection unit.
In accordance with other embodiments, a method involves capturing a sample of urine within a chamber of a testing apparatus. The method also involves sensing for presence of a predetermined characteristic in the urine within the chamber, and generating at least one electrical signal comprising information about the predetermined characteristic. The method may further involve transmitting data about the urine to a remote location.
The above summary is not intended to describe each disclosed embodiment or every implementation of the present disclosure. The figures and the detailed description below more particularly exemplify illustrative embodiments.
The figures are not necessarily to scale unless otherwise indicated. Like numbers used in the figures refer to like components. However, it will be understood that the use of a number to refer to a component in a given figure is not intended to limit the component in another figure labeled with the same number.
In the following description, reference is made to the accompanying set of drawings that form a part of the description hereof and in which are shown by way of illustration several specific embodiments. It is to be understood that other embodiments are contemplated and may be made without departing from the scope of the present disclosure. The following detailed description, therefore, is not to be taken in a limiting sense.
Unless otherwise indicated, all numbers expressing feature sizes, amounts, and physical properties used in the specification and claims are to be understood as being modified in all instances by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in the foregoing specification and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by those skilled in the art utilizing the teachings disclosed herein. The use of numerical ranges by endpoints includes all numbers within that range (e.g. 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5) and any range within that range.
Non-invasive point-of-care (POC) diagnostic instruments offer the unique capability of performing clinically-relevant measurements in biological fluids such as urine at the time of fluid sample extraction/excretion from the patient, without the need for sample storage and shipping required for lab-based tests. Non-invasive POC diagnostic instruments also enable fast turn-around-times providing timely results and feedback for titrating therapy. Analysis of urine, for example, is unique because of the timely occurrence or requirement of urinary excretion by the body, providing ample fluid volume to perform analytics to detect molecules or proteins of interest in the urine and assess the onset or progression of a disease state.
Kidney transplant patients, for example, are among many who could benefit immensely from a non-invasive diagnostic tool for urinalysis performed at the urine collection device, e.g., toilet, urinal, bladder catheter, etc., in order to monitor the health of the new kidney function in the body on a daily basis. There are close to 200,000 kidney transplant patients in the United States, and 20% of these patients are likely to have transplant failure in the first five years, with a post graft failure annual cost of $80,000/patient. Aside from invasive kidney biopsy, currently there is no gold-standard device for non-invasively monitoring or detecting the onset of a transplant failure in patients. A recent seminal urinalysis clinical trial demonstrated a positive correlation between increase in lymphocytes and renal tubular cells (RTCs) with kidney transplant rejection as early as five days prior to the event (see “Analysis of Urine Sediment for Cytology and Antigen Expression in Acute Renal Allograft Rejection An Alternative to Renal Biopsy,” Priti Chatterjee, MD, Sandeep R. Mathur, MD, Amit K. Dinda, MD, Sandeep Guleria, MS, Sandeep Mahajan, MD, V. K. Iyer, V. K. Arora, MD, Am J Clin Pathol. 2012; 137(5):816-824).
Although sample collection for urine cytology is simple, the analysis must still be performed in a clinical lab using existing techniques. A low cost, fully-automated point of care device for urine cytology consistent with embodiments of the present disclosure enables, at minimum, daily samples to be collected and analyzed on-site for cellular content. The more consistent frequency of sampling allows the cytological signs of allograft rejection to be identified as early as possible. More frequent sampling improves knowledge of urine cytology markers for rejection and potentially provides more advance warning of rejection so that proper treatment can be initiated.
Embodiments are directed to a non-invasive POC testing apparatus and method for use at a urine collection device, such as a toilet, urinal, bladder catheter and the like. In some of the examples provided herein, the urine collection device is referred to and shown as a toilet. It will be appreciated that the approaches described herein are also applicable to any other type of urine collection device, such as a urinal, a bladder catheter, etc. Capture and testing of a urine sample at the toilet (or other urine collection device) provides for assessment of the urine sample immediately after capture, thereby improving the quality of the assessment. The duration of time between collecting a urine sample and testing the sample can significantly impact the quality and accuracy of the assessment. The following changes, for example, occur in a urine sample with time after capture: 1) decreased clarity due to crystallization of solutes, 2) rising pH, 3) loss of ketone bodies, 4) loss of bilirubin, 5) dissolution of cells and casts, and 6) overgrowth of contaminating microorganisms. In general, urinalysis may not reflect the findings of fresh urine if the sample is greater than 1 hour old. Embodiments of the disclosure provide for testing (e.g., performing urinalysis) of a urine sample, such as a mid-stream sample, immediately after capture of the sample.
According to various embodiments, and with reference to
In some embodiments, each of the processes illustrated in
In accordance with some embodiments, and with reference to
According to other embodiments, and with reference now to
According to the embodiment shown in
In another scenario, the detection unit may be located in another room (e.g., a lab) distant from the bathroom within the same building or complex. The detection unit may be located distantly from the bathroom (e.g., in another city or state) and the chamber containing the urine sample may be transported (e.g., shipped, mailed) to the distantly located detection unit, which may be operated by a lab technician, for example.
The methodology of
In some embodiments, testing for cleanliness of the apparatus at the toilet involves sensing for an analyte of urine and determining whether a sense signal indicative of analyte presence exceeds a predetermined threshold. If not, the test indicates that the apparatus is sufficiently clear of urine from a previous test and is ready for another test cycle. If the test indicates presence of the analyte exceeds the predetermined threshold, a signal is generated indicating that the apparatus requires cleaning. Cleaning may also be indicated by other metrics, such as elapsed time since last cleaning, numbers of uses since last cleaning, signal characteristic changes (e.g. too high, too low, too noisy).
The signal includes information about one or more predetermined characteristics of the urine sample and can be transmitted from the apparatus at the urine collection device, e.g., toilet, to another system or device accessible to the person providing urine samples, a caregiver or a clinician. Optionally, a representation of the information carried by the signal may be displayed on a display. In some embodiments, the display may be located near the urine collection device, e.g., toilet, and may comprise one or more light emitting diodes (LEDs) that are activated or deactivated based on the information in the signal. For example, the display may comprise one red and one green LED, wherein activation of the green LED indicates a normal range of the predetermined characteristic of the urine and activation of the red LED indicates an abnormal range of the predetermined characteristic. In this configuration, the urine is analyzed and information about the urine characteristics are displayed to the user within a brief interval after capturing the urine.
In some embodiments, a more complex display may be used that is capable of providing a graphical or textual representation of the information. In some embodiments, the need for cleaning may be transmitted or indicated on the display. In some embodiments, an automatic cleaning process (e.g. flushing) and/or testing for cleanliness, may be activated automatically.
Turning now in
The diverter 406 includes a first port coupled to the conduit 410 which passes the volume of urine to be analyzed to the chamber 420 where the urine is contained. A second port of the diverter 406 is fluidically coupled to a conduit 408 which diverts urine received by the capturing arrangement 402 that is not part of the volume to be analyzed away from the chamber 420, e.g., into the toilet bowl. For example, in some scenarios, the second port (or a third port) of the diverter 406 can be used to divert excess urine away from the chamber 420 (e.g., into the toilet bowl) after a sufficient volume of urine has been captured in the chamber 420. In some embodiments that involve capturing mid-stream urine, the first- and last-voided urine may be diverted via the second port.
In the embodiment shown in
A detection unit 530 is shown situated at or near the chamber 520 and configured to sense for presence of a predetermined characteristic in the volume of the urine contained in the chamber 520. A single characteristic or a multiplicity of characteristics of the volume of urine may be subject to assessment by the detection unit 530. The detection unit 530 is configured to generate at least one electrical signal comprising information about the predetermined characteristic. According to embodiments that provide for detection of a multiplicity of predetermined characteristics of the volume of urine contained in the chamber 520, the detection unit 530 is configured to generate a multiplicity of electrical signals each comprising information about one of the predetermined multiplicity of characteristics. After the detection unit 530 completes the assessment of the urine sample, the urine contained in the chamber 520 can be expelled via an exit port 522. Prior to a subsequent urine capturing and assessment cycle, a cleansing operation may be conducted in which the cleansing solution is passed through the testing apparatus 500, or parts of the testing apparatus, so as to flush any remaining urine from the previous test cycle out of the apparatus 500.
A detection unit 630 is shown situated at or near the chamber 620 and configured to sense for presence of a predetermined characteristic in the volume of the urine contained in the chamber 620. A single characteristic or a multiplicity of characteristics of the volume of urine may be subject to assessment by the detection unit 630. The detection unit 630 is configured to generate at least one electrical signal comprising information about the predetermined characteristic. According to embodiments that provide for detection of a multiplicity of predetermined characteristics of the volume of urine contained in the chamber 620, the detection unit 630 is configured to generate a multiplicity of electrical signals, each comprising information about one of the predetermined multiplicity of characteristics. After the detection unit 630 completes the assessment of the urine sample, the urine contained in the chamber 620 is expelled via an exit port 622. Prior to a subsequent urine capture and assessment cycle, a cleansing operation may be conducted in which the cleansing solution is passed through the testing apparatus 600 or parts of the apparatus so as to flush any remaining urine from the previous test cycle out of the apparatus 600.
The diverter 706 is configured to divert a volume of urine to be tested that has been received by the capturing arrangement 702 to the detachable chamber 720 via conduit 710 for capture therein. A second port of the diverter 706 is fluidically coupled to a conduit 708 which diverts non-test urine received by the capturing arrangement 702 away from the chamber 720, such as into the toilet bowl. The second port or a third port of the diverter 706 can be used to divert excess urine away from the chamber 720 (e.g., into the toilet bowl) after a sufficient volume of urine has been collected in the chamber 720. After the detachable chamber 720 has collected a sufficient volume of urine, the chamber 720 can be removed from the chamber apparatus 718. The detachable chamber 720 incorporates a sealing arrangement that allows urine to be introduced into the chamber 720 and prevents urine from unintentionally escaping the chamber 720. The detachable chamber 720 may be transported to a detection unit configured to receive the chamber 720. The detection unit is configured to sense for presence of a predetermined characteristic in the volume of the urine and to generate at least one electrical signal comprising information about the predetermined characteristic.
Prior to a subsequent urine capture and assessment cycle, a cleansing operation may be conducted in which the cleansing solution is passed through the testing apparatus or parts of the apparatus so as to flush any remaining urine from the previous test cycle out of the apparatus. In some implementations, the container may be disposable. In other implementations, a portion of the container may be disposable or the container may be reusable. A reusable container or a reusable portion of the container may be cleaned during the cleaning cycle.
The diverter 707 is configured to divert a volume of urine to be tested that has been received by the capturing arrangement 703 to the chamber 730 via conduit 711 for capture therein. A second port of the diverter 707 is fluidically coupled to a conduit 709 which diverts non-test urine received by the capturing arrangement 703 away from the chamber 730, such as into the toilet bowl. The second port or a third port of the diverter 707 can be used to divert excess urine away from the chamber 730 (e.g., into the toilet bowl) after a sufficient volume of urine has been collected in the chamber 730.
The chamber 730 is fluidically connected to the detection unit 732 via a tube, pipe, or other device 731. The urine in the chamber 730 can be transported from the chamber 730 to the detection unit 732 through the pipe 731. Optionally, the transport of the volume urine to be tested between the chamber 730 and the detection unit 732 may be facilitated by a pump 733.
In some embodiments, the detection unit may be located in the same room as the capturing arrangement and chamber, e.g., on a table or counter in a bathroom. The detection unit is configured to sense for presence of a predetermined characteristic in the volume of the urine and to generate at least one electrical signal comprising information about the predetermined characteristic.
Prior to a subsequent urine capture and assessment cycle, a cleansing operation may be conducted in which the cleansing solution is passed through the testing apparatus or parts of the apparatus so as to flush any remaining urine from the previous test cycle out of the apparatus. In some implementations, the entire container may be disposable or a portion of the container may be disposable. In other implementations, the container may be reusable. A reusable container or a reusable portion of the container may be cleaned during the cleaning cycle.
Components of the testing apparatus 800 that are positioned within the toilet bowl 803 include a capturing arrangement 802 and a diverter 806 which can be integral to or separate from the capturing arrangement 802. In the example illustrated in
A detection unit 830 is situated within the housing 818 and in proximity to the chamber 820. The detection unit 830 is configured to sense for presence of the predetermined characteristic in the volume of the urine contained within the chamber 820. In some embodiments, examples of which are described herein, the detection unit 830 can include a compact, optical flow cytometer fluidically coupled to the chamber 820. The detection unit 830 is further configured to generate at least one electrical signal comprising information about the predetermined characteristic. In some embodiments, information generated by the detection unit 830 is stored in memory and may be periodically communicated to a remote system or device via a communication device 840. In some embodiments, the communication device 840 includes a wireless transceiver. The communication device 840 may be configured to implement a variety of wireless communication protocols, including those conforming to one or more of an IEEE 802.11b/g/n/ac/ad/af/ah, Bluetooth, Zigbee or WIMAX protocol, for example. In other embodiments, the communication device 840 includes a wired interface.
Optionally, the detection unit 830 may be communicatively coupled to a display 870. A representation of the information generated by the detection unit 830 can be displayed on the display 870. In some implementations, the display includes LEDs of different colors, e.g., a red LED and a green LED. The red LED can be activated when the predetermined characteristic is outside a normal range and the green LED can be activated if the predetermined characteristic is within the normal range. Alternatively or additionally, the display 870 may be capable of presenting a graphical or alphanumeric representation of the information.
After completing the assessment of the urine sample contained within the chamber 820, the urine can be expelled from the chamber 820 via a conduit 822. In some implementations, the conduit 822, e.g., tubing, can be configured to be routed through a gap between the toilet bowl 803 and the toilet seat 805. Alternatively, the conduit 822 can extend through an access port provided in the toilet bowl 803, which serves as a fluid pathway to return the expelled urine to the toilet bowl 803. In some embodiments, conduit 822 can share an access port with conduit 810. In some embodiments, conduit 819 and conduit 822 can use a separate access ports 807, 823. Although not shown, the conduit 822 can extend vertically upward from the access port 823 so that the distal end of the conduit 822 is above the water level within the toilet bowl 803. A seal is provided between the access port 823 of the toilet bowl 803 and the conduit 822 to prevent leakage of toilet water from the bowl 803 via the access port 823. In some embodiments, the conduit 822 can pass through the same access port 807 that accommodates conduit 810.
After completion of a urine assessment test, a cleansing operation can be performed. According to one cleansing approach, toilet water can be used to flush residual urine from the testing apparatus 800. A water supply line 852 can be connected to the water tank of the toilet 801 and transport fresh water to the capturing arrangement 802. An existing toilet and tank could be retrofitted by routing the water supply line 852 through a special flapper replacing a standard flapper. An irrigation manifold can be provided along the periphery of the capturing arrangement 802, which allows fresh water to cleanse the urine-receiving surface of the capturing arrangement 802. The fresh water received from the toilet tank passes through the diverter 806 and the conduits 808 and 810, thereby cleansing these structures. The fresh water passing through the conduit 810 fills up and passes through the chamber 820 of the external housing 818. The cleansing water passing through the testing apparatus 800 is expelled back into the toilet bowl 803 via conduit 822. A second water supply line 850 can be added to supply fresh water from the toilet tank directly to the chamber 822 to enhance cleansing of the chamber 822.
In some embodiments, a cleansing solution can be introduced into the cleansing operation at a convenient location. For example, a dispensing unit can be installed within the tank of the toilet 801 and connected to the water supply line 852. The dispensing unit can be configured to dispense a predetermined volume of cleaning solution (e.g. bleach, citric acid, detergent) into the water supply line 852 during each cleansing cycle. In other embodiments, a dispensing unit can be installed near or within the external housing 818 and fluidically connected to the water supply line 850. A predetermined volume of cleaning solution can be dispensed into the water supply line 850 and pumped into the irrigation manifold of the capturing arrangement 802 and, if desired, into the chamber 820 during each cleansing cycle.
The urine contained within the incubation chamber 1112 and the tags received from the receptacle 1115 are allowed to mix for a predetermined duration of time. After expiration of the predetermined duration of time, the mixture of urine and one or more tags is communicated to a detection chamber 1120. A metering sensor coupled to a processor (not shown) of the apparatus 1100 can be used to coordinate the transfer of urine through the various chambers and components of the apparatus 1100. For example, in some embodiments, the diverter 1106 is controlled by a liquid metering sensor. The desired portion of the urine flow is diverted to the incubation chamber 1112 when appropriate sensing conditions are met. For example after the initial 20 ml of urine have been omitted from the measurement, 15 ml of urine are diverted into the incubation chamber. Another approach could be to omit the first 10 seconds of the urine stream and divert the rest into the incubation chamber 1112. A metering sensor could be implemented by a liquid flow speed sensor, a thermometer, thermistor or other temperature sensor, a timer, an optical liquid plug detector or a combination of these metering sensors.
A detection unit 1130 is situated in proximity to the detection chamber 1120. A detector 1132 of the detection unit 1130 is configured to sense for presence of a predetermined characteristic or multiplicity of characteristics in the volume of the urine contained in the chamber 1120. After completion of the urine assessment by the detection unit 1130, the urine contained within the chamber 1120 is expelled, such as by use of a pump 1121.
Referring to the diverter 1106, various implementations can be employed to pass urine to the detection chamber 1120 for assessment by the detection unit 1130, e.g., mid-stream urine. A mid-stream of urine is generally understood in the medical community to be one in which the first half of bladder urine is discarded and the last half or a portion thereof is collected for evaluation. The first half of the stream serves to flush contaminating cells and microbes from the outer urethra prior to capture.
The diverter 1206 includes an inlet port 1220 which is fluidically coupled to a capturing arrangement adapted for use at the toilet. The inlet port 1220 is fluidically coupled to a first port 1222 and a second port 1224 via the valve 1210. In a first position, the valve 1220 diverts urine passing through the inlet port 1220 into the first port 1222, and prevents passage of the urine into the second port 1224. In a second position, the valve 1210 diverts urine passing through the inlet port 1220 into the second port 1224, and prevents passage of the urine into the first port 1222. At the initiation of a urine testing cycle, the valve 1210 is moved to the first position, so that first-voided urine is transported through the first port 1222 and discarded, such as by being expelled into the toilet bowl. After a predetermined duration of time, the valve 1210 is moved to the second position, allowing urine passing through the inlet port 1220 pass through the second port 1224 and into a chamber that collects the urine for subsequent testing.
In some embodiments, the valve 1210 may be controlled by a metering sensor. The desired portion of the urine flow is diverted to the sensing section of the device when appropriate sensing conditions are met. For example after the initial 20 ml of urine have been omitted from the measurement, 15 ml of urine are diverted into the sensing section. Another approach could be to omit the first 10 seconds of the urine stream and divert the rest into the sensing section. A metering sensor could be implemented by a liquid flow speed sensor, a thermometer, thermistor or other temperature sensor, a timer, an optical liquid plug detector or a combination of these metering sensors. The metering sensor can be coupled to a processor of the testing apparatus. The control signal generated by the metering sensor causes the valve 1210 to move between the first and second positions described above. The predetermined duration is a measure of time from the beginning of urination to a time during urination in which a person's urine stream can be considered suitable for testing, such as is required by a standard urinalysis. For example, in some embodiments, the metering sensor is a timer that moves the valve after a predetermined duration. The predetermined duration can be established based on average urination data for a population of individuals or can be tailored for the individual using the testing apparatus. For example, an individual's total urination time can be measured on a repeated basis, and an average urination time can be calculated using the testing apparatus deployed at the individual's toilet. The calculated average urination time for the individual can be used to establish the predetermined duration (e.g., 50% of the individual's average urination time) of the timer.
A testing apparatus of the present disclosure can be implemented to include one or more detection units configured to assess urine received from an individual. In some embodiments, a testing apparatus includes a detection unit configured to perform at an electrochemical assessment of a volume of urine. In other embodiments, a testing apparatus includes a detection unit configured to perform a chemical assessment of the volume of urine. In further embodiments, the testing apparatus includes a detection unit configured to perform a colorimetric assessment of a volume of urine. In some embodiments, a testing apparatus can be implemented to include a detection unit configured to perform a biochemical assessment of a volume of urine. According to further embodiments, a testing apparatus includes a detection unit configured to perform an immunoassay assessment of a volume of urine. It is understood that a testing apparatus can incorporate one or a multiplicity of these and other detection units.
In accordance with various embodiments, a testing apparatus deployable at a toilet includes a detection unit comprising an optical flow cytometer. According to some embodiments, an optical flow cytometer device is configured to detect the concentration of cells in urine in real-time to monitor the health of a kidney transplant, for example. According to some embodiments, an optical flow cytometer device is configured to detect the concentration of lymphocytes and/or RTCs in urine in real-time to monitor the health of a kidney transplant, for example. An optical flow cytometer can be deployed at a toilet and fluidically coupled to a capture apparatus within the toilet bowl (e.g., a funnel) for urine capture, thereby establishing a fluidic path to the cytometer. Deployment of the cytometer at the toilet allows real-time collected urine to be analyzed for the concentration of lymphocytes or RTCs, as well as for other analytes of interest. The flow cytometer can be part of the detection unit as described in
Traditional urinalysis involves centrifuging the urine sample (˜12 ml) and re-suspending the sample in 250 μl of urine, which is analyzed on a slide under a microscope where observed elements are quantified as the number per high power field. Automated urinalysis instruments such as Sysmex UF-1000i, Iris iQ200, sediMAX greatly increase the throughput in a lab-based setting and dramatically reduce labor and turn-around-times for results. From a technological point of view, every automated urinalysis instrument uses a different technology to classify and quantify urine sediment particles and offers an improvement in standardization over manual microscopy by eliminating potential inter-technician variability during slide interpretation. The Sysmex UF-1000i is presently the only instrument available in the market which employs flow cytometry and fluorophores to categorize cells in uncentrifuged urine labeled with fluorophores according to their fluorescence, size, impedance, and forward scattered light. Even though the instrument features adequate sensitivities, its specificity is still poor for differentiating the different elements, which therefore must be confirmed by manual microscopy by a trained technician following the cytometry measurement. Since a trained technician is crucial for initial urine sample preparation and positive manual identification of cells in the urine when using the Sysmex UF-1000i, this precludes the use of this instrument in a home or point-of-care setting which poses a significant barrier for patient compliance. In addition, the Sysmex UF1000i is currently priced at $125,000, posing a significant barrier for adoption of urine cytology as a routine test for patients in an out-patient clinic setting at site of sample capture.
Embodiments of the disclosure provide a new way of performing urine screening for renal transplant patients, bladder cancer, (chronic) bladder infection patients, diabetics, and patients with other significant (renal) disorders. Various embodiments disclosed herein are based on selective cell counts in urine samples. According to some embodiments, a detection unit is configured to detect cells by native protein fluorescence (e.g., excited around 280 nm) and size/shape analysis of the detected particles. Some embodiments are directed to avoiding any kind of specificity reagent to achieve a low-cost monitoring tool and an unrestricted means to dispose of the unaltered sample in the regular waste stream. Minimal sample preparation prevents any complication in reproducibility, while the frequent and high sample throughput ensures sensitivity. The specificity of the monitoring tool could be provided by a number of orthogonal metrics, e.g., the intensity of native protein fluorescence, by cell size, concentration and absolute count, and by the long term development of these values. In particular, an increase in cell count, especially of lymphocytes, renal tubular cells, and polymorphonuclear cells which can be a significant early predictor of transplant rejection. Table 1 below provides representative mean cell values in urine samples in acute renal rejection cases, which can be quantified and monitored over time using a testing apparatus of the present disclosure.
Various embodiments are directed to in-home monitoring utilizing a fully automated device that performs urine analysis for at-risk individuals, such as renal transplant patients, after each urination. In a representative system, at least 2 ml urine sample is analyzed after each sampling, resulting in typically up to 40,000 detected cells per ml of urine. With an expected flow rate of 0.2 ml/min, the total analysis time is typically under 15 minutes. In some implementations, the detection area is limited to about 1×0.15 mm, and the channel thickness is about 50 μm. This detection area is well compatible with an approximate one-to-one image of a light emitting diode (LED) excitation source on the detection area. The size of the detection region and the anticipated throughput can result in a sample speed of about 1 m/s, a well suited speed for real-time particle evaluation. The result of the analysis can be displayed on a display communicatively coupled to the testing device and/or communicated to healthcare specialists that can assess an immanent risk of transplant rejection and advise appropriate steps such as a change in immunosuppressant titration.
A testing apparatus configured for deployment at the toilet provides for mid-steam urine sample capture and disposal, reagent-free urine analysis based on selective cell identification, and means to communicate these measurements according to various embodiments. As discussed previously, components of the testing apparatus can be integrated in a replacement toilet seat. In some embodiments, the analyzer (e.g., flow cytometer) of the testing apparatus requires minimal maintenance, ideally only automated cleaning with standard household cleaners, and simple battery replacement if necessary. Due to the use of relatively inexpensive LEDs, embodiments of the disclosure are scalable to a low-cost format while maintaining adequate sensitivity and specificity. Specifically for the kidney transplant patient population, a testing apparatus of the present disclosure can be retrofitted in a home toilet to perform daily routine urine cytology with high compliance, to monitor or quantify allograft rejection markers for early failure diagnosis or to titrate immunosuppresive medication dose.
In accordance with various embodiments, a detection unit can be configured to detect cells in a sample of urine by native protein fluorescence. Reference is made to Table 2 below, which provides excitation and emission data for various representative metabolites. When exciting at 280 nm, for example, native fluorescence of proteins (tryptophan, tyrosine) dominates the UV-fluorescence emission between 300 to 370 nm, while Riboflavin emits in the visible range. Riboflavin's fluorescence signature can be used to identify eosinophils. Visible NADH (nicotinamide adenine dinucleotide) fluorescence is not as effectively excited at 280 nm, wavelengths around 260 nm or 340 nm can be used to do so.
Embodiments of a flow cytometer can be configured to implement spatial modulation detection in accordance with various embodiments. In spatially modulated detection, a continuously fluorescing bio-particle traverses an optical transmission pattern and thereby generates a time-dependent fluorescence signal. Correlating the detected signal with the known transmission pattern achieves high discrimination of the particle signal from background noise. It also allows for determining particle speed, particle size and particle aspect ratio. In conventional flow cytometry, the size of the excitation area is restricted approximately to the size of the particle. Spatial modulation detection according to the present disclosure uses a large excitation area which makes it possible to use LEDs or lamps as excitation light sources.
Traditional flow cytometry uses high excitation intensities in the detection area, while spatial modulation detection increase the total flux of fluorescence light that originates from a particle by integrating over a larger area. Therefore, it is possible to use inexpensive UV-LEDs that will soon be commercially available. The cost, power, and size constraints that a UV-laser would put on a system would be prohibitive to a deployment as a screening tool. According to one low-cost embodiment, for example, UV-LEDs with a total power of about 75 mW and a power density of 135 kW/m2 can be used at a projected initial cost of less than about $400. This power density is sufficient compared to the current power density of 500 kW/m2 that was used in the measurements determining leukocyte counts by native fluorescence excited at 266 nm.
A flow cytometer integrated in a urine testing apparatus of the present disclosure can be configured to determine particle size using spatial modulation detection. The use of spatial masks placed between the flow channel and detector provides several possibilities for size discrimination of continuously moving particles. One example of such a mask includes transparent regions at a fixed pitch of 30 μm. The actual opening widths decrease and then increase linearly by 1.5 μm. Maintaining a constant pitch is useful for frequency domain analysis to determine the particle speed and for particle triggering. The mask can have a folded design, with the larger openings at the edges and the smaller openings near the center to compensate for the excitation-intensity profile of the laser. A time-dependent signal arises from a fluorescing particle traversing this mask. The transmission times of particles passing under the openings is dependent on the widths of the opening. Approaches for determining the size of objects using the time-dependent signal are described in commonly owned U.S. patent application Ser. No. 14/181,530 entitled “Spatial Modulation of Light to Determine Object Length,” which is incorporated by reference in its entirety. Approaches for determining the size of color regions and and/or color homogeneity of objects using the time-dependent signal are described in commonly owned U.S. patent application Ser. No. 14/181,571 entitled “Determination of Color Characteristics of Objects Using Spatially Modulated Light,” which is incorporated by reference in its entirety.
Size measurements of particles can be used to gain cell specificity in urine samples. A detection window of cells can be gated to a size window of 9 to 20 μm, in order to exclude for example bacteria, cell clusters, and red blood cells from the relevant cell count. Such a detection window may allow for identification of renal tubular cells, macrophages, polymorphonuclear cells, and lymphocytes by size.
Cells of interest within a urine sample can be detected by autofluorescence according to some embodiments. Spatial modulation detection can be expanded from the visible into the ultra-violet spectral range and be used to detect objects, e.g., leukocytes, within a urine sample.
An experiment was performed to detect the presence of leukocytes in a buffer using a prototype flow cytometer in which cells were excited with a 20 mW, 266 nm CW laser at an intensity of about 500 kW/m2. The cytometer detected the autofluorescence of the cells in the wavelength range of 280 nm to 380 nm. The particle speed in these measurements was tuned to about 0.8 m/s. In the experiment, a fluidic quartz channel and a periodic emission mask were used to detect and count the particles. The experiment verified that leukocytes can be counted in buffer solutions based on fluorescence intensity. Other urine constituents, for example red blood cells, bacteria, etc., can be excluded by fluorescence intensity. More effective gating can be achieved by utilizing size discrimination as described above.
Across a variety of technological areas, absorption-encoded micro beads can be designed and implemented to function as miniature, free flowing sensors. Analysis approaches described herein can involve detection of micro beads that have been encoded, e.g. filled, injected, coated, stained or treated, etc. with combinations of dyes having excitation or emission spectra that are distinguishable from one another. The k dyes can be used to encode n types of micro beads such that each type of micro bead includes the k dyes in a proportional relationship that is different from the proportional relationships of the k dyes included in others of the n types of encoded micro beads. Each of the n types of micro bead may have characteristics different from other types of the micro beads, e.g., size, shape, charge, porosity, surface characteristics, elasticity, material composition and/or each type of micro bead may be respectively functionalized to recognize particular analytes present in a urine sample.
For example, encoded micro beads can be added to a urine sample that is taken from person using a toilet equipped with a testing apparatus of a type previously described. The absorption encoded micro beads are detected by a detector (e.g., analyzer) configured to sense for one or more predetermined characteristics or properties of the urine sample based on information obtained from the micro beads. This information may be based on the presence of fluorescence intensity of a secondary binder (a so-called “sandwich assay”) that binds to the analyte of interest which in turn is bound to the primary binder on the surface of the bead. As another example, in some implementations, the encoded micro beads can be functionalized with recognition elements that interact with certain analytes in a urine sample. Encoded micro bead of a particular type have primary binders to a specific analyte functionalized to their surface while other types of micro beads have other types of binders encoded on their surface. During analysis of the urine sample, the types of micro beads present in the sample are detected based on the absorption spectra of the characteristic combination of dyes that identifies the type of micro bead. Additionally, information about the presence and/or quantity of one or more analytes in the urine sample can be determined based on whether and/or to what extent the analytes have interacted with the recognition elements of the micro beads.
Embodiments described herein involve the use of micro beads that can be deployed in a variety of applications, including analysis of system properties and/or detection of the presence and/or amount of an analyte in a urine sample. In some implementations, such as advanced diagnostics that are performed in a lab (e.g., see embodiments shown in
In accordance with some embodiments, a detection unit for urinalysis can include a spatial filter having a plurality of mask features, and at least one optical detector positioned to sense light emanating from at least one object in the volume of urine moving along a flow direction with respect to the spatial filter. An intensity of the sensed light is time modulated according to the mask features. The optical detector is configured to generate a time varying electrical signal comprising a sequence of pulses in response to the sensed light. In some embodiments, the optical detector is configured to sense for native fluorescence emanating from the at least one object in the volume of the urine.
A representative detection unit is shown schematically in
The combined light source 1511 emits combined excitation light 1511a that includes first excitation light and second excitation light. The first and second excitation light may be combined using collimating lenses and a beam splitter. First excitation light is centered at or peaks at a first wavelength λ1, and second light is centered at or peaks at a second wavelength λ2. A third light source 1514 may emit third excitation light 1514a that is centered at or peaks at a third wavelength λ3. The confining member 1522 is substantially transmissive to wavelengths λ1, λ2, and λ3. The first, second, and third light sources are preferably solid-state devices such as laser diodes or LEDs. One of them preferably emitting around 280 nm.
In the depicted embodiment, combined light 1511a is internally reflected by surface 1515 and then internally reflects against a first upper inner surface 1522d of confining member 1522 as shown in the figure before illuminating the excitation region 1520c of the flow channel. Reflection on surfaces 1522d and 1515 might be due to total internal reflection, partial reflection due to refractive index mismatches between 1522 and 1523 respectively between 1522 and its surrounding environment, or due to partially mirrored surfaces of 1522. Light 1514a is similarly internally reflected by a second lower mirror 1517 and then internally reflects against the second upper inner surface portion 1522c of confining member 1522 before illuminating substantially the same excitation region 1520a. In some cases, one or more of mirrors 1517, 1515 may be omitted and replaced with total internal reflection (TIR) at an air interface, e.g. by providing suitable air gaps (note that the flow channel 1520 can be redirected or reconfigured such that it does not reside in the vicinity of mirrors 1517, 1515).
The first excitation light, which is a first component of combined excitation light 1511a, is effective to excite light emission from the encoding dyes of the bead (while not substantially exciting light emission from the second or third fluorophores); the second excitation light which is a second component of combined excitation light 1511a is effective to excite light emission from the secondary binder (while not substantially exciting light emission from the first or third fluorophores); and the third excitation light 1514a is effective to excite light emission from native fluorophores in cells (while not substantially exciting light emission from the first or second fluorophores that encode the micro beads and detect the presence of secondary binders).
Light emanating from the various micro beads and cells 1505, 1506 is detected by photosensitive detector 1532. Detector 1532 may have an associated spatial filter 1528 in order to derive more information from the excited micro beads. Detector 1532 may have associated spectral filters (not shown) in order to separate the fluorescence of micro beads, cells and secondary binders. As illustrated in
The detector 1532 provides a detector output which varies in time in accordance with at least: the passage of excited micro beads through the detection portion(s) of the flow channel 1523; the pattern of transmissive and non-transmissive regions of the spatial filter 1528; and the modulation of the excitation light sources. The detector output may be evaluated and analyzed using various known signal analysis techniques. An optical emission filter 1533 may be provided for detector 1532 in order to block at least any residual excitation light that would otherwise fall on the detector 1532, while transmitting at least some of the light emission from the first, second, and third fluorophores.
In an exemplary embodiment, the detection unit 1510 may be made in a relatively small format suitable for use in POC applications, such as within a testing apparatus mounted near or on a toilet. In such embodiment, the dimensions H1, H2, and H3 in
Another representative detection unit is shown schematically in
A first detector 1631 is positioned to sense light 1607a and generates an electrical signal in response to the sensed light 1607a. A second detector 1632 is positioned to sense light 1607b and generates an electrical signal in response to the sensed light 1607b. Additional electronics, e.g., signal processor and/or analyzer (not shown in
In some embodiments, the number of spectral channels separated and detected by designated detectors may be two as described here. In other embodiments, the number of spectral channels may be larger than two. A series of dichroic mirrors could further split the emanating light into more spectral channels, sensed by designated detectors.
Various embodiments of the disclosure can be implemented to test for specific components and/or characteristics of a urine sample acquired in a manner discussed herein. According to some of the approaches discussed herein, counts of cells (or other particles) with native fluorescence that are present in the urine can be determined. These cells are particles are excited by the input light and in response emit a fluorescence that has a different wavelength range than the excitation light.
According to some of the approaches discussed herein, counts of cells (or other particles) with native fluorescence and other optical properties can be determined. The other optical properties can include colorimetric measurements of urine color, refractive index of the urine which may be used to determine specific gravity and/or absorption of proteins in the urine, e.g., at about 280 nm, to provide a proteinuria test.
According to some approaches discussed herein, analysis may be based on specificity tags can be added to the urine during testing. For example, in some implementations, the approaches may be used to detect the presence of or count of cells that bind to certain specificity tags and/or cells that express certain proteins that bind to specificity tags. In either implementation, detection of the tag allows the cell to be identified.
According to some approaches, analysis may include detecting the presence and/or concentration of various analytes present, e.g., free floating, in the urine. For this implementation, color encoded beads could be used. In one implementation these beads could provide specific primary binding sites for the analyte of interest on their surface. A fluorescently labeled secondary binder would then inform about the presence and quantity of the analyte of interest by the amount of fluorescence intensity from the secondary binder. This quantification method is often referred to as “sandwich assay”.
Optical testing of urine composition has the advantage of being “contact-free”. This reduces complications due to fouling or unwanted growth of biofilms and it allows for easy cleaning. A detection unit of a testing apparatus deployed at a toilet, for example, can be configured to sense for presence of one or more of a predetermined ion or trace metal, a predetermined protein or enzyme, a predetermined type of cell, a predetermined molecule, urine specific gravity, osmolality, pH, or a predetermined bacterium in a urine sample immediately following capture (e.g., at a toilet). Specific dissolved analytes could be detected by their characteristic absorption or autofluorescence. They could also be detected by (multiplexed) bead assays. A prominent example for such an assay is the commercially available platform technology xMAP® from Luminex.
For example, a detection unit of a testing apparatus deployed at a toilet can be configured to sense for presence of one or more of proteinuria, leukocytes, ketones, and glucose in a urine sample immediately following capture (e.g., at a toilet). The detector unit can be configured to perform one or more of a chemical, electrochemical, biochemical, colorimetric, or immunoassay assessment of a urine sample acquired in real-time at the location of capture.
Urinalysis performed by a testing apparatus disclosed herein can reveal diseases that have gone unnoticed because they do not produce striking signs or symptoms. Examples include diabetes mellitus, various forms of glomerulonephritis, and chronic urinary tract infections. Normal, fresh urine is pale to dark yellow or amber in color and clear. Normal urine volume is in the range of 750 to 2000 ml/24 hr. A testing apparatus deployed at a person's toilet can assess the color and volume of urine produced during a 24 hour period (and multiple days) to determine if the color and volume of urine falls within or outside of normal ranges. A red or red-brown (abnormal) color could be from a food dye, eating fresh beets, a drug, or the presence of either hemoglobin or myoglobin. If the sample contains many red blood cells, it will be cloudy as well as red. Turbidity or cloudiness of a urine sample may be assessed by the testing apparatus. Turbidity or cloudiness may be caused by excessive cellular material or protein in the urine. The detection unit could have the capability of measuring turbidity by backscattered light from the sample. Coloring of urine could be measured by providing multispectral (e.g. “white”) light within the detector and measurement of the absorption spectrum. This measurement could be simplified by measuring the light intensity of light transmitted through the urine by a multitude of intensity sensors, each one sensitive only to parts of the illumination spectrum for example by different filters.
The testing apparatus may be configured to test for pH of a urine sample, for example using standard pH electrodes. The glomerular filtrate of blood plasma is usually acidified by renal tubules and collecting ducts from a pH of 7.4 to about 6 in the final urine. However, depending on the acid-base status, urinary pH may range from as low as 4.5 to as high as 8.0. The change to the acid side of 7.4 is accomplished in the distal convoluted tubule and the collecting duct.
Similarly, measurements with ion-selective electrodes can determine the concentration of predetermined ions. Elevated potassium and sodium ions in conjunction with increased urine pH values have been shown to promote urinary bladder carcinogenesis.
The testing apparatus may be configured to test for specific gravity of a urine sample. Specific gravity, which is directly proportional to urine osmolality which measures solute concentration, measures urine density, or the ability of the kidney to concentrate or dilute the urine over that of plasma. Specific gravity of urine between 1.002 and 1.035 on a random sample is generally considered normal if kidney function is normal. Since the specific gravity of the glomerular filtrate in Bowman's space ranges from 1.007 to 1.010, any measurement below this range indicates hydration and any measurement above it indicates relative dehydration. If specific gravity is not >1.022 after a 12 hour period without food or water, renal concentrating ability is impaired and the person either has generalized renal impairment or nephrogenic diabetes insipidus. In end-stage renal disease, specific gravity tends to become 1.007 to 1.010. Any urine having a specific gravity over 1.035 is either contaminated, contains very high levels of glucose, or the person may have recently received high density radiopaque dyes intravenously for radiographic studies or low molecular weight dextran solutions. In such cases, 0.004 can be subtracted from the measurement for every 1% glucose to determine non-glucose solute concentration.
For routine clinical purposes urine specific gravity is measured by the refractive index (RI) of urine. The refractive index of urine could for example be measured with differential refractometer to compensate for temperature effects or with a refractometer based on critical angles between the sample and a refracting prism of known refractive index. Another implementation could be based on a Fabry-Pérot interferometer (etalon).
The advantage of such an implementation would be the potential for refractive index measurements and free protein absorption measurements (around 280 nm) in the same optical cavity. The term “optical cavity” refers herein to a light-transmissive region that is at least partially bounded by light-reflective components, with the light-reflective components and the light-transmissive region having characteristics such that a measurable portion of light within the light-transmissive region is reflected more than once across the light-transmissive region. An “optical cavity component” is a component that includes one or more optical cavities. To provide more specificity, several optical cavities could be included in the detection unit. Each chamber could for example be equipped with molecular weight cut-off membranes that exclude analytes with molecular weight exceeding the cut-off weight from the refractive index or the absorption measurement. With this method the contribution of different constituents to the RI could be determined for example serum albumin (67 kDa) compared to small molecules including creatinine (113 Da).
The testing apparatus may be configured to test for various proteins in a urine sample. Normally, only small plasma proteins filtered at the glomerulus are reabsorbed by the renal tubule. However, a small amount of filtered plasma proteins and protein secreted by the nephron (Tamm-Horsfall protein) can be found in normal urine. Normal total protein excretion does not usually exceed 150 mg/24 hours or 10 mg/100 ml in any single specimen. More than 150 mg/day is defined as proteinuria. Proteinuria greater than 3.5 gm/24 hours is considered severe and known as nephrotic syndrome. Various proteins can be detected and counted using methods discussed hereinabove.
One or more of glucose, ketones, nitrite, and leukocytes in a urine sample can be detected and quantified using a testing apparatus of the present disclosure. Less than 0.1% of glucose normally filtered by the glomerulus appears in urine (<130 mg/24 hr). Glycosuria (excess sugar in urine) generally indicates diabetes mellitus. Ketones (acetone, aceotacetic acid, beta-hydroxybutyric acid) resulting from either diabetic ketosis or some other form of calorie deprivation (starvation) can be detected using techniques described herein. Nitrite in a urine sample can be detected. A positive nitrite test indicates that bacteria may be present in significant numbers in urine. Leukocytes can be detected and quantified using techniques described herein. A positive leukocyte assessment results from the presence of white blood cells either as whole cells or as lysed cells.
Systems, devices, or methods disclosed herein may include one or more of the features, structures, methods, or combinations thereof described herein. For example, a device or method may be implemented to include one or more of the features and/or processes described herein. It is intended that such device or method need not include all of the features and/or processes described herein, but may be implemented to include selected features and/or processes that provide useful structures and/or functionality.
In the above detailed description, numeric values and ranges are provided for various aspects of the implementations described. These values and ranges are to be treated as examples only, and are not intended to limit the scope of the claims. For example, embodiments described in this disclosure can be practiced throughout the disclosed numerical ranges. In addition, a number of materials are identified as suitable for various implementations. These materials are to be treated as exemplary, and are not intended to limit the scope of the claims.
The foregoing description of various embodiments has been presented for the purposes of illustration and description and not limitation. The embodiments disclosed are not intended to be exhaustive or to limit the possible implementations to the embodiments disclosed. Many modifications and variations are possible in light of the above teaching.
This application is a divisional of U.S. Ser. No. 14/307,193 filed Jun. 17, 2014, which is incorporated herein by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 14307193 | Jun 2014 | US |
| Child | 16201223 | US |
