WO2022081786A1 - Methods and devices for early diagnosis and monitoring of sepsis - Google Patents

Abstract

This invention discloses a method of prognosticating a likelihood of sepsis in a subject based on a determination of fluorescence emission strength of a blood sample of the subject. Also disclosed are systems and devices for measuring and determining a prognosis of sepsis in a subject suspected of having sepsis.

Description

METHODS AND DEVICES FOR EARLY DIAGNOSIS AND MONITORING OF SEPSIS

FIELD OF THE INVENTION

[0001] This invention pertains to the field of sepsis diagnosis. More particularly, the invention pertains to a method of diagnosing and monitoring sepsis utilizing fluorescence spectroscopy and a fluorometer for performing the method.

BACKGROUND OF THE INVENTION

[0002] Sepsis is the leading cause of death in ICU. Early diagnosis and proper treatment is key to lowering death rate. It has been estimated that every hour delay in treatment translates to about 8% decrease in survival rate. Thus, there is an 8- hour golden window for treating a sepsis patient. However, one cannot begin to treat a condition before it is diagnosed. To this end, prior art methods for diagnosing sepsis still fall far short of ideal. For example, the current gold-standard method is still blood culture, which takes about 48 - 72 hours. Other methods such as PCT tests are expensive and show only moderate accuracy in diagnosing sepsis.

[0003] Therefore, there exists an urgent need for a faster, cheaper, and more accurate method of diagnosing sepsis.

SUMMARY OF THE INVENTION

[0004] Embodiments of the present disclosure solve one or more of the foregoing or other problems in the art with diagnosing and monitoring sepsis in early stages. In particular, one or more embodiments can include methods for detecting tissue ischemia within a mammal by at least (i) isolating serum from a blood sample; (ii) directing an excitation light at the serum; (iii) receiving an endogenous serum chromophore emission light from the excited serum, and (iv) determining a likelihood of sepsis or absence thereof based on an intensity of the endogenous serum chromophore emission light.

[0005] In one exemplary embodiment, the excitation light is preferably one having a wavelength from about 350 - 400nm, more preferably about 385nm. In another embodiment, the excitation range is preferably from about 400 - 430nm, more preferably about 405nm. In yet another embodiment, the excitation wavelength is from about 450 - 488nm, more preferably about 460nm or about 488nm.

[0006] In some embodiments, the detection (emission) wavelength is preferably from about 440 - 470nm (corresponding to 350 - 400nm excitation). In some embodiments, the detection wavelength is from about 510 - 580nm (corresponding to 400 - 430nm excitation). In yet some other embodiments, the detection wavelength is from about 600 - 700nm (corresponding to 450 - 488nm excitation).

[0007] Additionally, or alternatively, determining the likelihood of sepsis or absence thereof can include determining that the intensity of the endogenous serum chromophore has exceeded a threshold intensity level, comparing the intensity of the endogenous serum chromophore emission light to a baseline emission intensity and determining the value of the baseline emission intensity to be lower than the intensity of the endogenous serum chromophore emission light, and/or comparing a real-time measurement of the intensity of the endogenous serum chromophore emission light to a first timepoint or a predetermined value associated with a nonsepsis condition.

[0008] In one aspect, isolating serum includes isolating serum at a catheter to repeatedly or constantly measure the intensity of the endogenous serum chromophore such that the likelihood of sepsis or absence thereof is determined contemporaneously with the real-time detection that the intensity of the endogenous serum chromophore has exceeded a threshold intensity level. In some instances, if the sepsis condition determined to be absent (or as yet to be determined as present), the methods of the present disclosure can include continuing to monitor the endogenous serum chromophore emission light of serum isolated at later timepoints.

[0009] In one aspect, isolating serum includes routing blood from a central venous/artery catheter to a microfluidic chip configured to separate the serum from the routed blood.

[0010] In one aspect, the methods additionally include implementing appropriate treatment or medical intervention based on the determination of the likelihood of sepsis or absence thereof. [0011] In one aspect, the trace amount of the exogenous chromophore is administered intravenously and can be indocyanine green (ICG), fluorescein, and/or methylene blue. For example, the exogenous chromophore can be ICG administered intravenously to an in vivo concentration at or below about 10’³ mg/mL.

[0012] In one aspect, the transdermal luminescence measurement of the chromophore is received through a lip, nail fold, ear lobe, or other dermal location of the mammal having a rich network of blood vessels and fewer pigments.

[0013] In one aspect, determining a likelihood of sepsis or absence thereof based on the transdermal luminescence measurement includes the steps of comparing the transdermal luminescence measurement to a healthy, expected luminescence measurement calculated from a known chromophore decay constant and based on an amount of time following administration of the solution.

[0014] In one aspect, the system additionally includes an adaptor configured in size and shape to couple to luminescence measurement apparatus, which can include the excitation light, the objective lens, the tissue mount, and/or the photodetector, among other luminescence measurement apparatuses. The adaptor can associate with a transparent port or branch part of a central venous/artery catheter. Additionally, or alternatively, the system includes a microfluidic chip venous/artery catheter. Additionally, or alternatively, the system includes a microfluidic chip configured to separate the serum from blood routed through a transparent port or branch part of the central venous/artery catheter.

[0015] In one aspect, the system additionally includes one or more band pass filters, notch filters, or long pass filters for blocking residual excitation light.

[0016] Accordingly, systems and method for the early diagnosis and monitoring of sepsis are disclosed. This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an indication of the scope of the claimed subject matter.

[0017] Other aspects and advantages of the invention will be apparent from the following description and the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] FIG. 1 shows an exemplary experiment where sepsis patients exhibit an emission intensity above a threshold baseline level of those exhibited by control subject.

[0019] FIG. 2 shows a schematics illustration for an exemplary point-of-care plasma fluorescence detector in accordance with embodiments of the present invention.

DETAILED DESCRIPTION

[0020] Before describing various embodiments of the present disclosure in detail, it is to be understood that this disclosure is not limited to the parameters of the particularly exemplified systems, methods, apparatus, products, processes, and/or kits, which may, of course, vary. Thus, while certain embodiments of the present disclosure will be described in detail, with reference to specific configurations, parameters, components, elements, etc., the descriptions are illustrative and are not to be construed as limiting the scope of the claimed invention. In addition, the terminology used herein is for the purpose of describing the embodiments and is not necessarily intended to limit the scope of the claimed invention.

Definitions

[0021] To assist in understanding the scope and content of the foregoing and forthcoming written description and appended claims, a select few terms are defined directly below.

[0022] The terms “about,” “approximately,” and “substantially,” as used herein, represent an amount or condition close to the stated amount or condition that still performs a desired function or achieves a desired result. For example, the terms “about,” “approximately,” and “substantially” may refer to an amount or condition that deviates by less than 10%, or by less than 5%, or by less than 1%, or by less than 0.1%, or by less than 0.01% from a stated amount or condition. [0023] As used herein, the terms “blood plasma” and “serum” are to be understood as functionally interchangeable and are meant to describe the liquid, non-cellular portion of blood.

[0024] The term “healthcare provider,” as used herein, generally refers to any licensed and/or trained person prescribing, administering, or overseeing the diagnosis and/or treatment of a patient or who otherwise tends to the wellness of a patient. This term may, when contextually appropriate, include any licensed medical professional, such as a physician, a physician’s assistant, a nurse, a nurse practitioner, a phlebotomist, a veterinarian, etc.

[0025] As used herein, the term “luminescence property” or “luminescence properties” include, but are not limited to, fluorescence spectra, fluorescence excitation spectra, fluorescence/phosphorescence lifetime, and fluorescence based ultra-/high-performance liquid chromatography tandem mass spectra.

[0026] The term “patient” generally refers to any animal, for example a mammal, under the care of a healthcare provider, as that term is defined herein, with particular reference to humans under the care of a physician or other relevant medical professional. For the purpose of the present application, a “patient” may be interchangeable with an “individual” or “person.” In some embodiments, the individual is a human patient.

[0027] The term “physician,” as used herein, generally refers to a medical doctor or similar licensed healthcare provider specialized medical doctor performing biopsies. This term may, when contextually appropriate, include any other medical professional, including any licensed medical professional or other healthcare provider, such as a physician’s assistant, a nurse, a veterinarian (such as, for example, when the patient is a non-human animal), etc.

[0028] As used herein, the term “real time” is understood to mean a present temporal occurrence. For example, an event is occurring in “real time” when an observation of the event occurs contemporaneously with the occurrence of the event. Additionally, real time calculations or determinations include those calculations or determinations that are being made based on data obtained contemporaneously with the measurement or receipt of the associated data. For clarity, contemporaneous events or actions are those that are coincident in time — that is, their occurrence is separated by no more than an hour, preferably by no more than 10 minutes, and more preferably by no more than 1 minute.

[0029] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present disclosure pertains.

[0030] Various aspects of the present disclosure, including devices, systems, and methods may be illustrated with reference to one or more embodiments or implementations, which are exemplary in nature. As used herein, the term “exemplary” means “serving as an example, instance, or illustration,” and should not necessarily be construed as preferred or advantageous over other embodiments disclosed herein. In addition, reference to an “implementation” of the present disclosure or invention includes a specific reference to one or more embodiments thereof, and vice versa, and is intended to provide illustrative examples without limiting the scope of the invention, which is indicated by the appended claims rather than by the following description.

[0031] As used throughout this application the words “can” and “may” are used in a permissive sense (i.e., meaning having the potential to), rather than the mandatory sense (i.e., meaning must). Additionally, the terms “including,” “having,” “involving,” “containing,” “characterized by,” as well as variants thereof (e.g., “includes,” “has,” “involves,” “contains,” etc.), and similar terms as used herein, including within the claims, shall be inclusive and/or open-ended, shall have the same meaning as the word “comprising” and variants thereof (e.g., “comprise” and “comprises”), and do not exclude additional un-recited elements or method steps, illustratively.

[0032] It will be noted that, as used in this specification and the appended claims, the singular forms “a,” “an” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to a singular referent (e.g., “widget”) includes one, two, or more referents. Similarly, reference to a plurality of referents should be interpreted as comprising a single referent and/or a plurality of referents unless the content and/or context clearly dictate otherwise. For example, reference to referents in the plural form (e.g., “widgets”) does not necessarily require a plurality of such referents. Instead, it will be appreciated that independent of the inferred number of referents, one or more referents are contemplated herein unless stated otherwise.

Overview of systems and methods

[0033] Systems and methods of the present disclosure utilize serum and/or plasma luminescence and its spectroscopic features for the early sensing of sepsis and shock conditions in organs. While not intending to be bound by any particular theory, the cytokine storm that ensues upon onset of sepsis may produce biochemical factors that are diffused and released systemically through the circulatory system, thus altering the photophysical or photochemical properties of blood. As implemented in the disclosed systems and methods, monitoring of blood luminescence can quickly and sensitively reflect the circulation microenvironment in a timely manner to provide actionable insights into the presence or absence of sepsis or potential organ dysfunction. Embodiments disclosed herein can bridge the diagnostic gap between sensitive symptom diagnoses e.g., physiologic monitoring) and specific markerbased diagnoses (e.g., diagnostic protein markers), resulting in an effective early screening modality.

[0034] Oxidative stress and/or cellular damage in that happen during sepsis can cause the release of signaling molecules (e.g., cytokines and chemokines) or radicals into the blood stream — whether directly or indirectly. The burst of biochemical factors can cause a perturbation within the physiology of blood cells, endothelial cells, and the change of chemical and physical microenvironment in serum and/or plasma. These factors may enhance, quench, or alter the luminescence properties of cells and plasma and/or may alter the chromatography features of these fluorophores.

[0035] In a first embodiment, the systems and methods of the present disclosure enable the detection of sepsis-induced perturbations in the chemical and physical microenvironment of serum and/or plasma using the luminescence properties of endogenous chromophores in serum and/or plasma. Compared to in vitro diagnosis of protein hallmarks, luminescence spectroscopy can selectively excite and sensitively detect various serum chromophores at trace amount and routinely monitor the change on demand. Advantageously, luminescence spectroscopy also does not require expensive antibodies for quantitative assay, which is convenient for on-site screening, and when combined with the assay of protein hallmarks such as procalcitonin (PCT), the likelihood of sepsis can be further confirmed.

[0036] In a second embodiment, the systems and methods of the present disclosure enable the detection of sepsis using luminescent dosimetry of endogenous or intravenously administered chromophores. The chromophores may associate with plasma proteins right after intravenous administration, and this chromophore-protein complex will be metabolized by certain organs, allowing the retention rate of the chromophore-protein complex to be used as a surrogate marker to reflect sepsis condition. For example, FDA approved ICG can associate with serum albumins and be specifically metabolized by the liver. Accordingly, the retention percentage at 15-minutes post ICG injection (ICG-15) can be used as a diagnostic index for the evaluation of liver function, which in turn can be used as an indicator for the degree and severity of sepsis. Normally, the ICG- 15 is below 10% of the initial concentration for a healthy person. On the other hand, if the liver function of a hepatocellular carcinoma patient is poor, as measured by the ICG- 15 being higher than 40%, then the patient is not eligible for a hepatectomy. When kidney failure occurs, the albumin-ICG complex may not be completely processed by the kidney, allowing the chromophore-protein complex to pass into the bladder, thereby causing the ICG- 15 value to be lower than that expected from normal metabolism by fully functioning organs. Details of how to assess liver function using blood luminescence can be found in US Patent Publication 20200093415 (the entire content of which is incorporated herein by reference).

[0037] Endogenous chromophores like bilirubin can associate with albumin and may be used instead of ICG to evaluate the liver function and/or detect kidney failure. For example, individuals who suffer from sepsis may have poor liver function. Such retention dosimetry of foreign/endogenous chromophores in serum can be used to measure or monitor organ function and detect failure of the organ.

[0038] Systems and methods of the present disclosure utilize sensitive photodetectors like photomultiplier tubes to detect weak luminescence signals, and by intentionally selecting the red or near infrared chromophores, the disclosed systems and methods mitigate background interference from tissues. For example, ICG can be excited at 780 nm and emit fluorescence longer than 810 nm, and bilirubin can be excited at 785 nm and luminesce between 800-850 nm. These wavelengths are much longer than the background autofluorescence of porphyrins (600- 750 nm). The systems and methods of the present disclosure implement luminescence dosimetry to evaluate the circulated chromophores at trace amounts, greatly reducing the required dosage of exogenous chromophores for accurate and reliable evaluation of organ function. As a result, the disclosed systems and methods can beneficially reduce patient exposure and toxicity to exogenous chromophores, and because a lower concentration of chromophores can be used, the costs associated with implementation can also be reduced.

[0039] As used herein, the term “endogenous chromophore” is intended to include at least reduced nicotinamide adenine dinucleotide (NADH), flavin adenine dinucleotide (FAD), flavin mononucleotide (FMN), riboflavin, or other flavins, bilirubin, biliverdin, and porphyrins but may additionally include other endogenous chromophores. It should be appreciated that aggregated forms of molecules may have different features of spectroscopy. Further, the exogenous chromophores disclosed herein for retention dosimetry include, but are not limited to, indocyanine green (ICG), fluorescein, and methylene blue.

[0040] In general, the embodiments disclosed herein can non-invasively (e.g., transdermally) monitor serum or plasma luminescence at anatomical locations having fewer pigments and a rich networks of vessels. For example, anatomical locations such as the mucosa on the lips, nail folds, or ear lobules are generally suitable for transdermal luminescence measurements. An objective lens can be used for efficient light excitation and luminescence collection, and to maximize the stability of signal acquisition, systems and methods of the present disclosure can include a tissue mount to fix the axial distance between vessel networks and the focusing lens. A tissue mount could be, for example, a metallic ring with air suction channels, so that tissues can be attached to the ring by applying a negative pressure in the air suction channels. Additionally, or alternatively, the access ports from central venous/artery catheters, commonly used in intensive care or surgery, can be used to collect serum and make routine measurement of luminescence. When available, use of the access ports can result in a better signal to noise ratio. In some embodiments, an adaptor can be designed to fit the luminescence measurement apparatus and can include, for example, the transparent port or branches on the parts of central venous/artery catheters. In some embodiments, a sterilized device for separating serum from blood cells, like a microfluidic chip, can be used.

[0041] It should be further appreciated that collected luminescence can be separated from excitation light using a beam-splitter, and the residual excitation light can be further blocked by one or more filters, such as a long-pass or short-pass filter, depending on the excitation mechanisms — single photon excitation typically use long-pass filters, while multiphoton excitation typically use short-pass filters — as known in the art. Further, conversion of the acquired luminescence signal to electric signals can be implemented by, for example, photomultiplier tubes, CCD detectors, or avalanche photo diodes with the signals being recorded by analogue devices or digital data-sampling cards, as known in the art.

[0042] If required, a light scanning module, containing scanning mirrors and lenses, can be used to steer the excitation beam and search for the location of blood vessels. Since tissues without vessels do not provide luminescence of serum chromophores, a scanning paradigm (e.g., line scanning or circular contour scanning) can be used to identify the location of vessels followed by signal verification to ensure the signal originated from serum. Advantageously, the luminescence from serum will be frequently blocked by red blood cells, allowing the extraction of the component of luminescence signal from vessels in frequency or speckle domain.

Systems and methods for sepsis diagnosis

[0043] Embodiments of the present disclosure enable the detection of sepsis in ICU patients from serum and/or plasma fluorescence.

[0044] For the diagnosis of sepsis conditions in ICU patients, physicians need to be suspicious of sepsis. The first part relies on patients’ symptoms, including but not limited to physiological signs including temperature, blood pressure, profiles of blood tests, or other vital signs. The second part relies on the companion diagnosis with confirmatory biomarkers and/or pathogen assays. However, it is often the case that the symptomology is too vague in the early stages of sepsis. Blood test usually take time to generate reports and often require medical experts to interpret the test data. These constraints and limitation of diagnostic resources are often the cause of late diagnosis of sepsis and consequently results in an increase in the mortality of patients.

[0045] The systems and methods disclosed herein provide a sensitive and quick screening tool that can be implemented on-site (point-of-care) to monitor and detect early-stage sepsis conditions. Following the detection of threshold conditions that indicate the likelihood of sepsis, protein markers can be used to confirm likelihood of sepsis. It should be appreciated that although the disclosed systems and methods are exemplified using sepsis and fluorescence spectroscopy to demonstrate the feasibility of this concept on human, the same may be applied to other non-human animals such as mammals.

[0046] In one embodiment, a method for detecting sepsis within a mammal (e.g., a rat) includes (i) isolating serum and/or plasma from a blood sample, (ii) directing an excitation light at the serum and/or plasma, (iii) receiving an endogenous serum and/or plasma chromophore emission light from the excited serum and/or plasma, and (iv) determining a likelihood of sepsis based on an intensity of the endogenous serum and/or plasma chromophore emission light.

[0047] The step of isolating serum and/or plasma can include, for example, serial centrifugation of a blood sample to obtain a final supernatant comprising the non- cellular, liquid fraction of the blood sample. It should be appreciated that the sample may include clotting components if an anticoagulant is used to store the blood sample prior to processing and may, in some cases, be more properly defined as blood plasma. Nevertheless, for the purposes of the present disclosure, the terms “serum” and “blood plasma” are understood to be functionally interchangeable.

[0048] Alternatively, serum can be isolated from the blood sample by other means, including, for example, by routing e.g., continuously or in batch) blood through a microfluidic chip, or similar device, configured to separate the serum from the blood. In one embodiment, the microfluidic chip can be coupled to the transparent port or branch part of a central venous/artery catheter where it continuously separates serum from blood routed therethrough.

[0049] The step of directing excitation light at the serum can include generating excitation light from any concentrated light source, such as a continuous wave laser. Preferably, the excitation light is configured to produce an excitation wavelength between about 440-490 nm, more preferably about 460 - 488nm, even more preferably at about 480 nm.

[0050] The step of receiving the endogenous serum chromophore emission light from the excited serum can be performed by an objective lens and/or photodetector positioned to receive the luminescence signals from the endogenous chromophore. In some instances, the serum is excited on a microscope slide or multi-well sample plate positioned within the optical axis of an imaging system (e.g., a high content imaging system, fluorescence microscope, or similar). Alternatively, the excited serum can be positioned within the optical axis of an objective lens and/or photodetector of an imaging system configured for real time monitoring of serum chromophore luminescence. Such an imaging system can include, among other things, a mount associated with the objective lens that is configured to fix an axial distance between the serum source and the objective lens. The serum source can be an anatomical location having fewer pigments and a rich network of blood vessels, such as the mucosa on the lips, nail folds, and ear lobules, or any other anatomical location that is generally suitable for transdermal luminescence measurements. When associated with an anatomical location, the mount may constitute a tissue mount having a tissue attachment mechanism for anchoring the tissue mount. As a non-limiting example, the tissue mount may include an air suction channel configured to pull a negative pressure at or near the target area.

[0051] In some instances, the mount is indirectly associated with an anatomical location and may include an adaptor. For example, the serum source may be a transparent port or branch part of a central venous/artery catheter (or microfluidic device associated therewith, as described above), and the mount associates directly with the transparent port or branch part directly, or indirectly through an adaptor associated therewith, to fix the axial distance between the serum source and the objective lens/photodetector. [0052] The endogenous serum chromophore emission light received from the excited serum may be captured at a single photon spectrometer and may have an emission wavelength from about 515 - 530 nm.

[0053] The transformed data obtained from determining the likelihood of sepsis can be used to inform actionable patient treatment and/or medical intervention steps. In one embodiment, the method includes conducting an in vitro assay of serum marker proteins such as procalcitonin to confirm the likelihood of sepsis, and if the sepsis condition is not present, the method includes continued monitoring of the endogenous serum chromophore emission light of serum isolated at later timepoints. The method may additionally include administering one or more pharmaceutical compositions, such as an anti-coagulant or clot breaking therapeutic (e.g., heparin), or other situation-dependent therapy.

[0054] In some embodiments, the step of determining a likelihood of sepsis condition based on an intensity of the endogenous serum chromophore emission light can include comparing the intensity of the endogenous serum chromophore emission light to a baseline emission intensity. A baseline emission intensity having a lower value than the intensity of the endogenous serum chromophore emission light can be indicative of sepsis condition. In some instances (FIG. 1), the baseline emission intensity is a threshold emission intensity, an emission light intensity value associated with a first (or earlier) timepoint, or a predetermined value associated with a non-sepsis condition. For example, serum can be isolated at a catheter for repeated or constant measurements of the intensity of the endogenous serum chromophores, and the presence of an ischemic condition can be determined by identifying an intensity of the endogenous serum chromophore that has exceeded a threshold intensity level.

Computer Systems

[0055] In some embodiments, some of the steps within the foregoing methods and/or components of the associated systems may be controlled by or include a computer system. Such computer systems can include one or more processors and one or more hardware storage devices having stored thereon computer-executable instructions that, when executed by at least one of the one or more processors, configure the computer system to perform one or more acts. For example, the computer system can be configured to direct the excitation light to excite the endogenous and/or exogenous chromophore, automatically identify the one or more blood vessels within the target area using a line scanning or circular contour scanning module comprising scanning mirrors and lenses configured to steer the excitation light within the target area, receive luminescence signals at the photodetector electronically coupled to the computer system and positioned in an emission light path of the objective lens, and/or determine a presence of tissue ischemia and/or liver dysfunction based on the luminescence signals. FIG. 2 illustrates an exemplary computer-controlled system where serums is automatically fed into an analyzer for processing, excitation, and detection.

[0056] The computer-executable instructions may additionally cause the computer system to calculate an optical index and/or dosimetry curve based on the luminescence signals received at the photodetector. The computer-executable instructions may additionally cause the computer system to calculate and compare the dosimetry curve to a standard decay constant of the exogenous chromophore within a healthy mammal to inform the determination of organ dysfunction. It should be appreciated that other desired functionalities or automations of the disclosed systems may be implemented on a computer system.

[0057] It will be further appreciated that computer systems are increasingly taking a wide variety of forms. In this description and in the claims, the term “computer system” or “computing system” is defined broadly as including any device or system — or combination thereof — that includes at least one physical and tangible processor and a physical and tangible memory capable of having thereon computerexecutable instructions that may be executed by a processor. By way of example, not limitation, the term “computer system” or “computing system,” as used herein is intended to include personal computers, desktop computers, laptop computers, tablets, hand-held devices (e.g., mobile telephones, PDAs, pagers), microprocessorbased or programmable consumer electronics, minicomputers, mainframe computers, multi- processor systems, network PCs, distributed computing systems, datacenters, message processors, routers, switches, and even devices that conventionally have not been considered a computing system, such as wearables (e.g., glasses).

[0058] The memory may take any form and may depend on the nature and form of the computing system. The memory can be physical system memory, which includes volatile memory, non-volatile memory, or some combination of the two. The term “memory” may also be used herein to refer to non-volatile mass storage such as physical storage media.

[0059] The computing system also has thereon multiple structures often referred to as an “executable component.” For instance, the memory of a computing system can include an executable component. The term “executable component” is the name for a structure that is well understood to one of ordinary skill in the art in the field of computing as being a structure that can be software, hardware, or a combination thereof.

[0060] For instance, when implemented in software, one of ordinary skill in the art would understand that the structure of an executable component may include software objects, routines, methods, and so forth, that may be executed by one or more processors on the computing system, whether such an executable component exists in the heap of a computing system, or whether the executable component exists on computer-readable storage media. The structure of the executable component exists on a computer-readable medium in such a form that it is operable, when executed by one or more processors of the computing system, to cause the computing system to perform one or more functions, such as the functions and methods described herein. Such a structure may be computer-readable directly by a processor — as is the case if the executable component were binary. Alternatively, the structure may be structured to be interpretable and/or compiled — whether in a single stage or in multiple stages — so as to generate such binary that is directly interpretable by a processor.

[0061] The term “executable component” is also well understood by one of ordinary skill as including structures that are implemented exclusively or near-exclusively in hardware logic components, such as within a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), Program- specific Standard Products (ASSPs), System-on-a-chip systems (SOCs), Complex Programmable Logic Devices (CPLDs), or any other specialized circuit. Accordingly, the term “executable component” is a term for a structure that is well understood by those of ordinary skill in the art of computing, whether implemented in software, hardware, or a combination thereof.

[0062] The terms “component,” “service,” “engine,” “module,” “control,” “generator,” or the like may also be used in this description. As used in this description and in this case, these terms — whether expressed with or without a modifying clause — are also intended to be synonymous with the term “executable component” and thus also have a structure that is well understood by those of ordinary skill in the art of computing.

[0063] While not all computing systems require a user interface, in some embodiments a computing system includes a user interface for use in communicating information from/to a user. The user interface may include output mechanisms as well as input mechanisms. The principles described herein are not limited to the precise output mechanisms or input mechanisms as such will depend on the nature of the device. However, output mechanisms might include, for instance, speakers, displays, tactile output, projections, holograms, and so forth. Examples of input mechanisms might include, for instance, microphones, touchscreens, projections, holograms, cameras, keyboards, stylus, mouse, or other pointer input, sensors of any type, and so forth.

[0064] Accordingly, embodiments described herein may comprise or utilize a special purpose or general-purpose computing system. Embodiments described herein also include physical and other computer-readable media for carrying or storing computer-executable instructions and/or data structures. Such computer- readable media can be any available media that can be accessed by a general purpose or special purpose computing system. Computer- readable media that store computer-executable instructions are physical storage media. Computer-readable media that carry computer-executable instructions are transmission media. Thus, by way of example — not limitation — embodiments disclosed or envisioned herein can comprise at least two distinctly different kinds of computer-readable media: storage media and transmission media. [0065] Computer-readable storage media include RAM, ROM, EEPROM, solid state drives (“SSDs”), flash memory, phase-change memory (“PCM”), CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other physical and tangible storage medium that can be used to store desired program code in the form of computer-executable instructions or data structures and that can be accessed and executed by a general purpose or special purpose computing system to implement the disclosed functionality of the invention. For example, computer-executable instructions may be embodied on one or more computer-readable storage media to form a computer program product.

[0066] Transmission media can include a network and/or data links that can be used to carry desired program code in the form of computer-executable instructions or data structures and that can be accessed and executed by a general purpose or special purpose computing system. Combinations of the above should also be included within the scope of computer-readable media.

[0067] Further, upon reaching various computing system components, program code in the form of computer-executable instructions or data structures can be transferred automatically from transmission media to storage media (or vice versa). For example, computer-executable instructions or data structures received over a network or data link can be buffered in RAM within a network interface module (e.g., a “NIC”) and then eventually transferred to computing system RAM and/or to less volatile storage media at a computing system. Thus, it should be understood that storage media can be included in computing system components that also — or even primarily — utilize transmission media.

[0068] Those skilled in the art will further appreciate that a computing system may also contain communication channels that allow the computing system to communicate with other computing systems over, for example, a network. Accordingly, the methods described herein may be practiced in network computing environments with many types of computing systems and computing system configurations. The disclosed methods may also be practiced in distributed system environments where local and/or remote computing systems, which are linked through a network (either by hardwired data links, wireless data links, or by a combination of hardwired and wireless data links), both perform tasks. In a distributed system environment, the processing, memory, and/or storage capability may be distributed as well.

[0069] Those skilled in the art will also appreciate that the disclosed methods may be practiced in a cloud computing environment. Cloud computing environments may be distributed, although this is not required. When distributed, cloud computing environments may be distributed internationally within an organization and/or have components possessed across multiple organizations. In this description and the following claims, “cloud computing” is defined as a model for enabling on-demand network access to a shared pool of configurable computing resources (e.g., networks, servers, storage, applications, and services). The definition of “cloud computing” is not limited to any of the other numerous advantages that can be obtained from such a model when properly deployed.

A cloud-computing model can be composed of various characteristics, such as on- demand self-service, broad network access, resource pooling, rapid elasticity, measured service, and so forth. A cloud-computing model may also come in the form of various service models such as, for example, Software as a Service (“SaaS”), Platform as a Service (“PaaS”), and Infrastructure as a Service (“laaS”). The cloudcomputing model may also be deployed using different deployment models such as private cloud, community cloud, public cloud, hybrid cloud, and so forth.

[0070] Although the subject matter described herein is provided in language specific to structural features and/or methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the described features or acts so described. Rather, the described features and acts are disclosed as example forms of implementing the claims.

Claims

CLAIMS What is claimed is:

1. A method for determining a likelihood of a subject suspected of having sepsis, comprising: directing an excitation light at a sample of blood from the subject; measuring a fluorescent emission intensity from the sample; comparing the emission intensity with a predetermined threshold value, wherein if said emission intensity is higher than the predetermined value, a likelihood of sepsis is determined.

2. The method of claim 1, the method of claim 1, wherein said excitation light is one selected from 385nm, 405nm, 460nm, or 488nm.

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SUBSTITUTE SHEET (RULE 26)