Perfusion and oxygenation measurements

Abstract

The present disclosure provides methods and apparatus for assessing blood flow in damaged or healing tissue. The present disclosure also provides methods for identifying patients at risk for developing or at risk for developing a pressure ulcer and treating the patient using an anatomically specific clinical intervention selected based on perfusion or blood oxygenation values, or a combination thereof. The present disclosure also provides methods for stratifying patient groups based on risk of wound development and methods for reducing the incidence of tissue damage in a nursing facility. The present disclosure also provides methods for analyzing trends in perfusion or oxygenation measurements to detect tissue damage before it is visible, and methods for comparing bilaterally symmetrical perfusion values ​​to identify damaged tissue.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional Application No. 62 / 698,684, filed on July 16, 2018, and U.S. Provisional Application No. 62 / 849,700, filed on May 17, 2019, the entire contents of which are incorporated herein by reference in their entirety. Technical Field

[0003] The present disclosure provides methods and apparatus for assessing blood flow in damaged or healing tissue. The present disclosure also provides methods for identifying patients at risk for developing or at risk for developing a pressure ulcer and treating the patient using an anatomically specific clinical intervention selected based on measurements of blood perfusion or oxygenation values, or a combination thereof. The present disclosure also provides methods for stratifying patient groups based on risk of wound development, and methods for reducing the incidence or severity of tissue damage in patients admitted to a nursing facility. The present disclosure also provides apparatus and computer-readable media for measuring a patient's blood perfusion to identify damaged tissue for anatomically specific clinical intervention, and methods for identifying damaged tissue. The present disclosure also provides methods for detecting tissue damage before the damage is visible on the patient's skin. Background Art

[0004] The skin is the body's largest organ. It is susceptible to a wide range of injuries and injuries. When the skin and surrounding tissues are unable to redistribute external pressure and mechanical forces, skin damage and injury can occur, and ulcers may form. Prolonged, continuous exposure to even moderate pressure, such as the pressure exerted by a supine patient's weight on the skin surface of their buttocks, can lead to pressure sores. Regular exposure to even moderate levels of pressure and stress, in the presence of other insults, such as neuropathy and weakened surrounding tissues caused by diabetes, can lead to ulcers, such as foot ulcers.

[0005] In the United States, approximately 2.5 million people develop pressure ulcers each year, and a similar number occur in the European Union. Up to 25% of elderly and paralyzed patients in long-term and intensive care settings will develop a pressure ulcer. Approximately 60,000 Americans die each year from infections and other complications related to pressure ulcers.

[0006] Most pressure sores develop over bony prominences where there is less compressed tissue and the pressure gradient within the vascular network is altered. Pressure sores are classified into one of six stages, ranging from: skin remains intact but redness may appear over the bony prominence—the earliest currently recognized stage (Stage 1), to tissue breakdown with exposure of bone, tendon, or muscle (Stage 4), to deep tissue pressure injury with non-fading dark red, maroon, or purple patches, and to full-thickness skin blurring and tissue loss (Stage Undefined). In major economies, the goal of policymakers and care providers is to detect and treat pressure sores before the skin breaks down to avoid progression to later stages. Most pressure sores are preventable, and if they are identified before Stage 1, deterioration of the underlying tissues can be prevented.

[0007] It is desirable for patients and society to detect tissue damage before the skin breaks down and intervene with appropriate treatment to avoid further deterioration of the underlying tissue. The average cost of treating pressure-induced injuries at the earliest visible sign (stage 1 ulcer) is only But when the ulcer is deep enough to expose muscle or bone (stage 4 ulcer), the average cost rises to See, e.g., Brem, H. et al. (2010). High Cost of Stave IV Pressure Ulcers. Am. J. Surg. Oct; 200(4): 473-477. Currently, patients typically receive global pressure ulcer prevention, meaning that prevention is not targeted to any specific anatomical site. Only after a pressure ulcer has developed to a point where it can be identified by visual assessment do patients receive targeted local ulcer treatment. The current standard for detecting pressure ulcers is visual inspection, which is subjective, unreliable, untimely, and lacks specificity. See, for example, Pancorbo-Hidalgo P. et al. (2006). Risk assessment scales for pressure ulcer prevention: a systematic review. Journal of Advanced Nursing, 54, 94-110; Garcia-Fernandez, FP (2014). Predictive Capacity of Risk Assessment Scales and Clinical Judgment for Pressure Ulcers: A Meta-analysis. Journal of Wound, Ostomy and Continence Nursing 41, 24-34. Therefore, even if a patient is experiencing skin inflammation, a precursor to ulcer development, he or she will not receive targeted topical treatment for the developing ulcer. Instead, the inflammation will continue to develop into a full-blown ulcer.

[0008] Certain types of surgery can also cause skin damage and injury. For example, reconstructive surgery involving skin flaps can sever blood vessels in or around the surgical site. The healing of damaged or separated tissue depends on the restoration of adequate blood flow throughout the damaged area. It can be difficult to determine by visual inspection whether an area of ​​tissue is healing, that is, whether blood flow through the tissue is increasing to normal levels. Existing devices can measure certain properties, such as the oxygenation level of the blood, but these properties are only indirect measurements of blood flow.

[0009] Fluorescein has been used clinically for over 40 years to evaluate flap vascularity. Fluorescein emits a yellow-green (510-600 nm) fluorescence when excited by ultraviolet (UV) light. Tissue with good blood flow will appear bright yellow, while areas without blood flow will appear dark blue. Fluorescein is typically administered as a 500-1000 mg bolus injection. After a 20-30 minute wait, the tissue can be evaluated using a UV lamp. This method takes 30 minutes to administer and can only be used once every 8 hours.

[0010] Near-infrared spectroscopy (NIRS) determines the ratio of oxygenated to deoxygenated hemoglobin by illuminating specific wavelengths of light (760 nm and 830 nm) and measuring the amount of reflected or transmitted light. Currently, devices are available that provide images showing local oxygenation at the skin's surface. While this is important clinical information, it does not reveal the actual perfusion level of the tissue, nor can it differentiate the condition of superficial tissue from that of deeper tissue layers.

[0011] Currently, two types of Doppler instruments are used clinically. The first is ultrasonic Doppler, which senses the phase shift of reflected sound to measure the velocity of moving elements, presumably red blood cells (RBCs) in blood vessels. The second is laser Doppler, which senses the phase shift of reflected light to detect RBC velocity. These methods are limited to assessing blood flow in larger vessels and are unable to evaluate perfusion in smaller arteries and capillaries. Summary of the Invention

[0012] A systematic approach is provided for identifying the risk of developing pressure ulcers prior to visible skin damage using non-invasive objective measurements and then administering personalized interventions at specific anatomical structures. Also provided is a systematic approach for identifying the risk of developing pressure ulcers prior to visible skin damage using non-invasive objective measurements and then administering personalized interventions at specific anatomical structures. Further provided is a method for monitoring wound healing progress and consistency of intervention adherence.

[0013] In one aspect, the present disclosure provides and includes a device for evaluating blood perfusion in tissue beneath the skin of a patient. The device includes: an emitter configured to emit light of a first wavelength and a second wavelength when activated; a first receiver configured to measure a first intensity of the received light of the first wavelength and a second intensity of the received light of the second wavelength, and to provide a first signal including information about the first and second intensities of the received light; a substrate coupled to the emitter and the first receiver and configured such that the emitter and the first receiver can be placed in contact with the patient's skin simultaneously; and a processor coupled to the first receiver. The processor is configured to receive the first signal, determine a first sum of the first and second intensities of the received light, and determine a perfusion level of the tissue based on the first sum.

[0014] In one aspect, the present disclosure provides and encompasses a method for evaluating blood perfusion in tissue beneath the skin of a patient. The method comprises the steps of emitting light toward the patient's skin at a first location. The light has a first wavelength and a second wavelength. The method further comprises the steps of receiving a portion of the emitted light that has reflected from the tissue, measuring a first intensity of the received light at the first wavelength and a second intensity of the received light at the second wavelength, and determining a first sum value of the first and second intensities of the received light.

[0015] In one aspect, the present disclosure provides and includes a device for evaluating blood perfusion in tissue beneath the skin of a patient. The device includes an emitter configured to selectively emit light of a first wavelength or emit light of a second wavelength; a camera configured to form a first image of reflected light of the first wavelength and a second image of reflected light of the second wavelength; and a substrate coupled to the emitter and the camera. The substrate can be positioned so that the light emitted by the emitter illuminates a portion of the patient's skin within the field of view of the camera. The device also includes a display; and a processor coupled to the camera and the display and configured to: receive the first and second images, form a third image that is the sum of the first and second images, and provide the third image to the display.

[0016] In one aspect, the present disclosure provides and includes a method for reducing the incidence of wound development in a patient admitted to a nursing facility, the method comprising the steps of: assessing a patient's risk of tissue damage upon admission to the nursing facility, wherein the assessing step comprises: performing a first plurality of perfusion measurements at one or more body locations of the patient at risk for wound development; calculating a first delta value based on a portion of the first plurality of perfusion measurements; determining whether the first delta value exceeds a first threshold; administering a level 0 first intervention if the first delta value does not exceed the first threshold; and administering a level N intervention if the first delta value exceeds the first threshold, wherein N is an integer and the value of N is 1 or greater. In one aspect, the one or more body locations at risk for wound development are selected from the group consisting of: flesh tissue over the patient's sternum, sacrum, heel, scapula, elbow, ear, and other bony prominences. In one aspect, the one or more body locations at risk for wound development include one or more anatomical sites that are in prolonged contact with a medical device and are selected from the group consisting of: cheek, nose, chest, stomach, and lower abdominal areas.

[0017] In one aspect, the present disclosure provides and includes a method for reducing the incidence of wound development in a patient admitted to a nursing facility, the method comprising the steps of: assessing the patient's risk of tissue damage upon admission to the nursing facility, wherein the assessing step comprises: taking a first plurality of SpO2 measurements at one or more body locations of the patient at risk for wound development; determining whether any of the first plurality of SpO2 measurements is below a first threshold; applying a level 0 first intervention if the first plurality of SpO2 measurements is greater than or equal to the first threshold; and applying a level N intervention if any of the first plurality of SpO2 measurements is less than the first threshold, wherein N is an integer and the value of N is 1 or greater. In one aspect, the one or more body locations at risk for wound development are selected from the group consisting of: flesh tissue over the patient's sternum, sacrum, heel, scapula, elbow, ear, and other bony prominences. In one aspect, the one or more body locations at risk for wound development include one or more anatomical sites that are in prolonged contact with a medical device and are selected from the group consisting of: cheek, nose, chest, stomach, and lower abdominal areas.

[0018] In one aspect, the present disclosure provides and includes a method for stratifying patient groups in a care facility based on risk of wound development, the method comprising the steps of: performing a plurality of perfusion measurements at one or more body locations selected for monitoring for each of the patients; calculating a delta value based on a portion of the plurality of perfusion measurements for each of the patients; determining whether each delta value exceeds any of a set of thresholds corresponding to N levels of care and assigning a level of care to each of the patients; and rearranging the patient groups based on the level of care assigned to each of the patients. In one aspect, the one or more body locations for monitoring are selected from the group consisting of: the patient's sternum, sacrum, heel, scapula, elbow, ear, and other bony prominences of the patient. In one aspect, the one or more body locations for monitoring include one or more anatomical sites that are in chronic contact with a medical device and are selected from the group consisting of: the cheek, nose, chest, stomach, and lower abdominal area.

[0019] In one aspect, the present disclosure provides and includes a method for stratifying groups of patients in a care facility based on risk of wound development, the method comprising the steps of: taking a plurality of SpO2 measurements at one or more body locations selected for monitoring for each of the patients; determining whether each of the plurality of SpO2 measurements is below any of a set of thresholds corresponding to N levels of care and assigning a level of care to each of the patients; and rearranging the group of patients according to the level of care assigned to each of the patients. In one aspect, the one or more body locations for monitoring are selected from the group consisting of: the patient's sternum, sacrum, heel, shoulder blade, elbow, ear, and other bony prominences of the patient. In one aspect, the one or more body locations for monitoring include one or more anatomical sites that are in chronic contact with a medical device and are selected from the group consisting of: the cheek, nose, chest, stomach, and lower abdominal area.

[0020] In one aspect, the present disclosure provides and encompasses a method for identifying and providing an appropriate level of care to a patient based on multiple blood perfusion measurements of tissue beneath the patient's skin. In one aspect, based on multiple blood perfusion measurements of tissue beneath the patient's skin, an anatomically specific intervention is provided to the patient. In one aspect, based on changes in the perfusion measurements, increasingly intensive therapeutic interventions are provided to the patient. In one aspect, based on changes in the perfusion measurements, a less intensive therapeutic intervention is administered to the patient.

[0021] In one aspect, the present disclosure provides and encompasses a method for identifying and providing an appropriate level of care to a patient based on multiple blood oxygenation (SpO2) measurements of tissue beneath the patient's skin. In one aspect, an anatomically specific intervention is provided to the patient based on multiple SpO2 measurements of tissue beneath the patient's skin. In one aspect, an increasingly intensive therapeutic intervention is provided to the patient based on changes in the SpO2 measurements. In one aspect, a less intensive therapeutic intervention is administered to the patient based on changes in the SpO2 measurements.

[0022] In one aspect, the present disclosure provides and includes a method of evaluating a patient, the method comprising the steps of: performing an initial blood perfusion measurement at a body location selected for monitoring; and assigning a risk category to the patient, the risk category selected from a group comprising a plurality of risk categories, wherein the assignment is based in part on the initial perfusion measurement at the body location.

[0023] In one aspect, the present disclosure provides and includes a method of evaluating a patient, the method comprising the steps of: taking an initial SpO2 measurement at a body location selected for monitoring; and assigning a risk category to the patient, the risk category selected from a group comprising a plurality of risk categories, wherein the assignment is based in part on the initial SpO2 measurement at the body location.

[0024] In one aspect, the present disclosure provides and includes a method for managing patient care, the method comprising the steps of: performing an initial assessment of the patient upon admission to a nursing facility and taking an initial set of perfusion measurements for all body locations selected for monitoring; calculating an initial delta value for each body location selected for monitoring; determining that the patient's measurements are abnormal and setting an intervention level N=1 if any initial delta value is greater than or equal to a first threshold; implementing N levels of intervention for each body location with a delta value greater than or equal to the first threshold; and taking perfusion measurements for all body locations at N levels of frequency and calculating new delta values. In one aspect, the one or more body locations for monitoring are selected from the group consisting of: the patient's sternum, sacrum, heel, scapula, elbow, ear, and other bony prominences of the patient's flesh and skin. In one aspect, the one or more body locations for monitoring include one or more anatomical sites that are in chronic contact with a medical device and are selected from the group consisting of: cheek, nose, chest, stomach, and lower abdominal areas.

[0025] In one aspect, the present disclosure provides and includes a method of managing patient care, the method comprising the steps of: performing an initial assessment of the patient upon admission to a nursing facility and taking an initial set of SpO2 measurements for all body locations selected for monitoring; determining that the patient's measurement is abnormal if any of the initial SpO2 measurements is less than a first threshold and setting an intervention level N=1; implementing N levels of intervention for each body location where the SpO2 measurement is less than the first threshold; and taking SpO2 measurements for all body locations at N levels of frequency.

[0026] In one aspect, the present disclosure provides and includes a method for identifying and treating a patient at risk of tissue damage, the method comprising the steps of: assessing the patient's risk of tissue damage upon admission to a nursing facility, wherein the assessing step comprises: performing a first plurality of perfusion measurements in the patient; calculating a first Δ value based on a portion of the first plurality of perfusion measurements; determining whether the first Δ value exceeds a first threshold; if the first Δ value does not exceed the first threshold, applying a level 0 first intervention; and if the first Δ value exceeds the first threshold, applying a level N first intervention, wherein N is an integer and the value of N is 1 or greater. In a further aspect, the present disclosure provides and includes: performing a second plurality of perfusion measurements in a patient at a first predetermined frequency corresponding to a level of intervention administered; calculating a second delta value based on a portion of the second plurality of perfusion measurements; determining whether the second delta value exceeds a second threshold; if the second delta value does not exceed the second threshold, continuing to administer the first intervention; if the second delta value does not exceed the second threshold, continuing to perform a plurality of perfusion measurements at the first predetermined frequency; if the second delta value exceeds the second threshold, administering a second intervention of level M, where M is an integer and M is greater than N; and if the second delta value exceeds the second threshold, performing a plurality of perfusion measurements at a second predetermined frequency corresponding to level M. In an even further aspect, the present disclosure provides and includes: determining whether the second delta value is less than a third threshold; if the second delta value is less than the third threshold and if the first intervention is not level 0, administering level (N-1) of intervention; and if the second delta value is less than the third threshold, performing a plurality of perfusion measurements at a predetermined frequency corresponding to level (N-1).

[0027] In one aspect, the present disclosure provides and includes a method for identifying and treating a patient at risk of tissue damage, the method comprising the steps of: assessing the risk of tissue damage in a patient upon admission to a nursing facility, wherein the assessing step comprises: taking a first plurality of SpO2 measurements in the patient; determining whether any of the first plurality of SpO2 measurements is below a first threshold; applying a level 0 first intervention if the first plurality of SpO2 measurements is greater than or equal to the first threshold; and applying a level N first intervention if any of the first plurality of SpO2 measurements is less than the first threshold, wherein N is an integer and the value of N is 1 or greater. In a further aspect, the present disclosure provides and includes: taking a second plurality of SpO2 measurements in a patient at a first predetermined frequency corresponding to a level of intervention administered; calculating a time delta value based on a difference between the first and second plurality of SpO2 measurements; determining whether the time delta value is a decrease exceeding a second threshold; if the time delta value does not exceed the second threshold, continuing to administer the first intervention; if the time delta value does not exceed the second threshold, continuing to take a plurality of perfusion measurements; if the time delta value is a decrease exceeding the second threshold, administering a second intervention of level M, where M is an integer and M is greater than N; and if the time delta value is a decrease exceeding the second threshold, taking a plurality of SpO2 measurements at a second predetermined frequency corresponding to level M. In a further aspect, the present disclosure provides and includes: determining whether the time delta value is an increase exceeding a third threshold; if the time delta value is an increase exceeding the third threshold and if the first intervention is not level 0, administering level (N-1) of intervention; and if the time delta value is an increase exceeding the third threshold, taking a plurality of SpO2 measurements at a predetermined frequency corresponding to level (N-1).

[0028] In one aspect, the present disclosure provides and includes a method for slowing the progression of skin and tissue damage in a patient in need thereof, the method comprising the steps of: identifying a level K current intervention being received by the patient; taking a plurality of perfusion measurements in the patient; calculating a delta value based on a portion of the plurality of perfusion measurements; determining whether the delta value exceeds a first threshold; if the delta value does not exceed the first threshold, continuing to administer the current intervention threshold; if the delta value does not exceed the first threshold, continuing to administer a plurality of perfusion measurements at a predetermined frequency corresponding to the level K; if the delta value exceeds the first threshold, administering a level N new intervention, where N has a value greater than K; and if the delta value exceeds the first threshold, administering a plurality of perfusion measurements at a predetermined frequency corresponding to the level N. In a further aspect, the present disclosure provides and includes: determining whether the delta value is less than a second threshold; if the delta value is less than the second threshold, administering a level L intervention, where L has a non-negative value less than K; and if the delta value is less than the second threshold, administering a plurality of perfusion measurements at a predetermined frequency corresponding to the level L.

[0029] In one aspect, the present disclosure provides and includes a method for slowing the progression of skin and tissue damage in a patient in need thereof, the method comprising the steps of: identifying a level K current intervention being received by the patient; taking a plurality of SpO2 measurements in the patient; determining whether any of the plurality of SpO2 measurements exceeds a first threshold; continuing to administer the current intervention if the plurality of SpO2 measurements are within a threshold range corresponding to the K level; taking a plurality of perfusion measurements at a predetermined frequency corresponding to the K level if the Δ value is within a threshold range corresponding to the K level; administering a level N new intervention if any of the plurality of SpO2 measurements is below the first threshold range, where the value of N is greater than K; and taking a plurality of perfusion measurements at a predetermined frequency corresponding to the N level if any of the plurality of SpO2 measurements is below the first threshold range. In a further aspect, the present disclosure provides and includes: determining whether any of the multiple SpO2 measurements is above a threshold range corresponding to level K; if any of the multiple SpO2 measurements is above the threshold range, administering a level L intervention, where L has a non-negative value less than K; and if any of the multiple SpO2 measurements is above the threshold range corresponding to level K, taking multiple SpO2 measurements at a predetermined frequency corresponding to level L.

[0030] In one aspect, the present disclosure provides and includes a method for identifying and treating a patient who needs to have skin cream applied to their heel, the method comprising the steps of: taking multiple perfusion measurements at the patient's heel; calculating a Δ value based on a portion of the multiple perfusion measurements; determining whether the Δ value exceeds a threshold corresponding to level N, where N is greater than or equal to 2; applying skin cream to the patient's heel if the Δ value exceeds the threshold; and taking multiple perfusion measurements every two hours if the Δ value exceeds the threshold.

[0031] In one aspect, the present disclosure provides and includes a method for identifying and treating a patient who needs to have a lotion applied to their heel, the method comprising the steps of: taking multiple SpO2 measurements at the patient's heel; determining whether any of the multiple SpO2 measurements is below a threshold corresponding to level N, where N is greater than or equal to 2; applying a lotion to the patient's heel if any of the multiple SpO2 measurements is below the threshold; and taking multiple SpO2 measurements every two hours if any of the multiple SpO2 measurements is below the threshold.

[0032] In one aspect, the present disclosure provides and includes a method for identifying and treating a patient requiring neuromuscular stimulation to their heel, the method comprising the steps of: performing multiple perfusion measurements at the patient's heel; calculating a Δ value based on a portion of the multiple perfusion measurements; determining whether the Δ value exceeds a threshold corresponding to level N, where N is greater than or equal to 2; applying neuromuscular stimulation to the patient's heel if the Δ value exceeds the threshold; and performing multiple perfusion measurements every hour if the Δ value exceeds the threshold.

[0033] In one aspect, the present disclosure provides and includes a method of identifying and treating a patient in need of neuromuscular stimulation applied to their heel, the method comprising the steps of: taking a plurality of SpO2 measurements at the patient's heel; determining whether any of the plurality of SpO2 measurements is below a threshold corresponding to level N, where N is greater than or equal to 2; applying neuromuscular stimulation to the patient's heel if any of the plurality of SpO2 measurements is below the threshold; and taking a plurality of SpO2 measurements every hour if any of the plurality of SpO2 measurements is below the threshold.

[0034] In one aspect, the present disclosure provides and includes a method of identifying and treating a patient who requires application of a topical cream to their heel, the method comprising the steps of: taking a plurality of perfusion measurements at the patient's heel; calculating a delta value based on a portion of the plurality of perfusion measurements; determining whether the delta value exceeds a threshold corresponding to a level N, where N is greater than or equal to 2; applying a topical cream to the patient's heel if the delta value exceeds the threshold; and taking a plurality of perfusion measurements every half hour if the delta value exceeds the threshold.

[0035] In one aspect, the present disclosure provides and includes a method of identifying and treating a patient who needs application of a topical cream to their heel, the method comprising the steps of: taking a plurality of SpO2 measurements at the patient's heel; determining whether any of the plurality of SpO2 measurements is below a threshold corresponding to level N, where N is greater than or equal to 2; applying a topical cream to the patient's heel if any of the plurality of SpO2 measurements is below the threshold; and taking a plurality of SpO2 measurements every half hour if any of the plurality of SpO2 measurements is below the threshold.

[0036] In one aspect, the present disclosure provides and includes a method for identifying and treating a patient who requires a heel boot to be applied to their heel, the method comprising the steps of: taking a plurality of perfusion measurements at the patient's heel; calculating a Δ value based on a portion of the plurality of perfusion measurements; determining whether the Δ value exceeds a threshold corresponding to level N, where N is greater than or equal to 2; applying a heel boot to the patient's heel if the Δ value exceeds the threshold; and taking a plurality of perfusion measurements every half hour if the Δ value exceeds the threshold.

[0037] In one aspect, the present disclosure provides and includes a method of identifying and treating a patient who requires application of a heel boot to their heel, the method comprising the steps of: taking a plurality of SpO2 measurements at the patient's heel; determining whether any of the plurality of SpO2 measurements is below a threshold corresponding to level N, where N is greater than or equal to 2; applying a heel boot to the patient's heel if any of the plurality of SpO2 measurements is below the threshold; and taking a plurality of SpO2 measurements every half hour if any of the plurality of SpO2 measurements is below the threshold.

[0038] In one aspect, the present disclosure provides and includes a method for identifying and treating a patient who needs to have skin cream applied to their sacrum, the method comprising the steps of: performing multiple perfusion measurements at the patient's sacrum; calculating a Δ value based on a portion of the multiple perfusion measurements; determining whether the Δ value exceeds a threshold corresponding to level N, where N is greater than or equal to 2; applying skin cream to the patient's sacrum if the Δ value exceeds the threshold; and performing multiple perfusion measurements every six hours if the Δ value exceeds the threshold.

[0039] In one aspect, the present disclosure provides and includes a method for identifying and treating a patient who needs to have skin cream applied to their sacrum, the method comprising the steps of: taking multiple SpO2 measurements at the patient's sacrum; determining whether any of the multiple SpO2 measurements is below a threshold corresponding to level N, where N is greater than or equal to 2; applying skin cream to the patient's sacrum if any of the multiple SpO2 measurements is below the threshold; and taking multiple SpO2 measurements every six hours if any of the multiple SpO2 measurements is below the threshold.

[0040] In one aspect, the present disclosure provides and includes a method for identifying and treating a patient requiring neuromuscular stimulation to their sacrum, the method comprising the steps of: performing multiple perfusion measurements at the patient's sacrum; calculating a Δ value based on a portion of the multiple perfusion measurements; determining whether the Δ value exceeds a threshold corresponding to level N, where N is greater than or equal to 2; applying neuromuscular stimulation to the patient's sacrum if the Δ value exceeds the threshold; and performing multiple perfusion measurements every four hours if the Δ value exceeds the threshold.

[0041] In one aspect, the present disclosure provides and includes a method of identifying and treating a patient in need of neuromuscular stimulation applied to their sacrum, the method comprising the steps of: taking a plurality of SpO2 measurements at the patient's sacrum; determining whether any of the plurality of SpO2 measurements is below a threshold corresponding to level N, where N is greater than or equal to 2; applying neuromuscular stimulation to the patient's sacrum if any of the plurality of SpO2 measurements is below the threshold; and taking a plurality of SpO2 measurements every four hours if any of the plurality of SpO2 measurements is below the threshold.

[0042] In one aspect, the present disclosure provides and encompasses a method of identifying and treating a patient requiring application of a topical cream to their sacrum, the method comprising the steps of: taking a plurality of perfusion measurements at the patient's sacrum; calculating a delta value based on a portion of the plurality of perfusion measurements; determining whether the delta value exceeds a threshold corresponding to a level N, where N is greater than or equal to 2; applying a topical cream to the patient's sacrum if the delta value exceeds the threshold; and taking a plurality of perfusion measurements every two hours if the delta value exceeds the threshold.

[0043] In one aspect, the present disclosure provides and encompasses a method of identifying and treating a patient in need of application of a topical cream to their sacrum, the method comprising the steps of: taking a plurality of SpO2 measurements at the patient's sacrum; determining whether any of the plurality of SpO2 measurements is below a threshold corresponding to level N, where N is greater than or equal to 2; applying a topical cream to the patient's sacrum if any of the plurality of SpO2 measurements is below the threshold; and taking a plurality of SpO2 measurements every two hours if any of the plurality of SpO2 measurements is below the threshold.

[0044] In one aspect, the present disclosure provides and encompasses a method for identifying and treating a patient in need of therapeutic ultrasound, the method comprising the steps of: taking a plurality of perfusion measurements at an anatomical site of the patient; calculating a delta value based on a portion of the plurality of perfusion measurements; determining whether the delta value exceeds a threshold corresponding to level N, where N is greater than or equal to 2; administering therapeutic ultrasound to the anatomical site if the delta value exceeds the threshold; and taking a plurality of perfusion measurements every two hours if the delta value exceeds the threshold. In one aspect, the anatomical site is selected from the group consisting of: the patient's sternum, sacrum, heel, scapula, elbow, ear, and other bony prominences of the patient.

[0045] In one aspect, the present disclosure provides and encompasses a method of identifying and treating a patient in need of therapeutic ultrasound, the method comprising the steps of: taking a plurality of SpO2 measurements at an anatomical site of the patient; determining whether any of the plurality of SpO2 measurements is below a threshold corresponding to level N, where N is greater than or equal to 2; and administering therapeutic ultrasound to the anatomical site if any of the plurality of SpO2 measurements is below the threshold. In one aspect, the anatomical site is selected from the group consisting of: the patient's sternum, sacrum, heel, scapula, elbow, ear, and other bony prominences of the patient.

[0046] In one aspect, the present disclosure provides and includes a method of identifying and treating a patient in need of shock wave therapy, the method comprising the steps of: taking a plurality of perfusion measurements at an anatomical site of the patient; calculating a delta value based on a portion of the plurality of perfusion measurements; determining whether the delta value exceeds a threshold corresponding to level N, where N is greater than or equal to 2; administering shock wave therapy to the anatomical site if the delta value exceeds the threshold; and taking a plurality of perfusion measurements every two hours if the delta value exceeds the threshold. In one aspect, the anatomical site is selected from the group consisting of: the patient's sternum, sacrum, heel, scapula, elbow, ear, and other bony prominences of the patient. In one aspect, the shock wave therapy is provided by electromagnetic pulses or pressurized air.

[0047] In one aspect, the present disclosure provides and encompasses a method of identifying and treating a patient in need of shock wave therapy, the method comprising the steps of: taking a plurality of SpO2 measurements at an anatomical site of the patient; determining whether any of the plurality of SpO2 measurements is below a threshold corresponding to level N, where N is greater than or equal to 2; and administering shock wave therapy to the anatomical site if any of the plurality of SpO2 measurements is below the threshold. In one aspect, the anatomical site is selected from the group consisting of: the patient's sternum, sacrum, heel, scapula, elbow, ear, and other bony prominences of the patient. In one aspect, the shock wave therapy is provided by electromagnetic pulses or pressurized air.

[0048] In one aspect, the present disclosure provides and encompasses a method of identifying and treating a patient requiring application of a 30-degree wedge, the method comprising the steps of: taking a plurality of perfusion measurements at an anatomical site of the patient; calculating a delta value based on a portion of the plurality of perfusion measurements; determining whether the delta value exceeds a threshold corresponding to level N, where N is greater than or equal to 2; applying a 30-degree wedge to the anatomical site if the delta value exceeds the threshold; and taking a plurality of perfusion measurements every two hours if the delta value exceeds the threshold. In one aspect, the anatomical site is selected from the group consisting of: flesh tissue over the patient's sternum, sacrum, heel, scapula, elbow, ear, and other bony prominences.

[0049] In one aspect, the present disclosure provides and encompasses a method of identifying and treating a patient requiring application of a 30-degree wedge, the method comprising the steps of: taking a plurality of SpO2 measurements at an anatomical site of the patient; determining whether any of the plurality of SpO2 measurements is below a threshold corresponding to level N, where N is greater than or equal to 2; and applying a 30-degree wedge to the anatomical site if any of the plurality of SpO2 measurements is below the threshold. In one aspect, the anatomical site is selected from the group consisting of: flesh tissue over the patient's sternum, sacrum, heel, scapula, elbow, ear, and other bony prominences.

[0050] In one aspect, the present disclosure provides and encompasses a method of identifying and treating a patient requiring application of a composite dressing, the method comprising the steps of: taking a plurality of perfusion measurements at an anatomical site of the patient; calculating a delta value based on a portion of the plurality of perfusion measurements; determining whether the delta value exceeds a threshold corresponding to level N, where N is greater than or equal to 2; applying a composite dressing to the anatomical site if the delta value exceeds the threshold; and taking a plurality of perfusion measurements every two hours if the delta value exceeds the threshold. In one aspect, the anatomical site is selected from the group consisting of: flesh tissue over the patient's sternum, sacrum, heel, scapula, elbow, ear, and other bony prominences.

[0051] In one aspect, the present disclosure provides and encompasses a method of identifying and treating a patient requiring application of a composite dressing, the method comprising the steps of: taking a plurality of SpO2 measurements at an anatomical site of the patient; determining whether any of the plurality of SpO2 measurements is below a threshold corresponding to level N, where N is greater than or equal to 2; and applying a composite dressing to the anatomical site if any of the plurality of SpO2 measurements is below the threshold. In one aspect, the anatomical site is selected from the group consisting of: flesh tissue over the patient's sternum, sacrum, heel, scapula, elbow, ear, and other bony prominences.

[0052] In one aspect, the present disclosure provides and encompasses a method for identifying and treating a patient in need of a hybrid mattress, the method comprising the steps of: taking a plurality of perfusion measurements at an anatomical site of the patient; calculating a delta value based on a portion of the plurality of perfusion measurements; determining whether the delta value exceeds a threshold corresponding to a level N, where N is greater than or equal to 2; providing a hybrid mattress to support the patient if the delta value exceeds the threshold; and taking a plurality of perfusion measurements every two hours if the delta value exceeds the threshold. In one aspect, the anatomical site is selected from the group consisting of: the patient's sternum, sacrum, heel, scapula, elbow, ear, and other bony prominences of the patient.

[0053] In one aspect, the present disclosure provides and encompasses a method of identifying and treating a patient in need of a hybrid mattress, the method comprising the steps of: taking a plurality of SpO2 measurements at an anatomical site on the patient; determining whether any of the plurality of SpO2 measurements is below a threshold corresponding to level N, where N is greater than or equal to 2; and providing a hybrid mattress to support the patient if any of the plurality of SpO2 measurements is below the threshold. In one aspect, the anatomical site is selected from the group consisting of: the patient's sternum, sacrum, heel, scapula, elbow, ear, and other bony prominences of the patient.

[0054] In one aspect, the present disclosure provides and encompasses a method for identifying and treating a patient in need of a powered mattress, the method comprising the steps of: taking a plurality of perfusion measurements at an anatomical site of the patient; calculating a delta value based on a portion of the plurality of perfusion measurements; determining whether the delta value exceeds a threshold corresponding to level N, where N is greater than or equal to 2; providing a powered mattress to support the patient if the delta value exceeds the threshold; and taking a plurality of perfusion measurements every two hours if the delta value exceeds the threshold. In one aspect, the anatomical site is selected from the group consisting of: the patient's sternum, sacrum, heel, scapula, elbow, ear, and other bony prominences of the patient.

[0055] In one aspect, the present disclosure provides and encompasses a method of identifying and treating a patient requiring application of a powered mattress, the method comprising the steps of: taking a plurality of SpO2 measurements at an anatomical site on the patient; determining whether any of the plurality of SpO2 measurements is below a threshold corresponding to level N, where N is greater than or equal to 2; and providing a powered mattress to support the patient if any of the plurality of SpO2 measurements is below the threshold. In one aspect, the anatomical site is selected from the group consisting of: flesh over the patient's sternum, sacrum, heel, scapula, elbow, ear, and other bony prominences.

[0056] In one aspect, the present disclosure provides and includes an apparatus for identifying damaged tissue, the apparatus comprising: a perfusion measurement device of the present disclosure for evaluating blood perfusion in tissue beneath the skin of a patient; a processor electronically coupled to the perfusion measurement device and configured to receive information from the perfusion measurement device and convert information about the measured reflected light into a perfusion value; a non-transitory computer-readable medium electronically coupled to the processor and including instructions stored thereon that, when executed on the processor, perform the following steps: determining a difference between a first perfusion value corresponding to a measurement taken at a first location on the patient's skin and a second perfusion value corresponding to a measurement taken at a second location on the patient's skin, wherein the second location is bilaterally symmetrical relative to the first location.

[0057] In one aspect, the present disclosure provides an apparatus for identifying damaged tissue, the apparatus comprising: a substrate configured to be placed against a surface of a patient's skin; a perfusion measurement device of the present disclosure for evaluating blood perfusion in tissue beneath the patient's skin, comprising: a plurality of transmitters and a plurality of receivers disposed at corresponding positions on the substrate; a processor electronically coupled to the perfusion measurement device and configured to receive information about reflected light measurements from the plurality of receivers and convert the information into corresponding plurality of perfusion values; and a non-transitory computer-readable medium electronically coupled to the processor and comprising instructions stored thereon, which, when executed on the processor, perform the following steps: identifying a first receiver and a second receiver located at first and second positions bilaterally symmetrical relative to the patient's skin from the plurality of perfusion values; and comparing a first perfusion value associated with the first receiver with a second perfusion value associated with the second receiver.

[0058] In one aspect, the present disclosure provides a device for identifying damaged tissue, the device comprising: a device body; at least one transmitter; a first receiver and a second receiver, wherein the two receivers are arranged on the device body to allow the first receiver to be positioned at a first position on the patient's skin and the second receiver to be simultaneously positioned at a second position that is bilaterally symmetrical relative to the first position; a processor, electronically coupled to the two receivers and configured to receive a first reflected light measurement from the first position and a second reflected light measurement from the second position, and convert the first reflected light measurement into a first perfusion value, and convert the second reflected light measurement into a second perfusion value; and a non-transitory computer-readable medium, electronically coupled to the processor and containing instructions that, when executed on the processor, perform the step of determining a difference between the first perfusion value and the second perfusion value.

[0059] In one aspect, the present disclosure provides a method for identifying damaged tissue, the method comprising: obtaining a first perfusion value from a first location on a patient's skin; obtaining a second perfusion value from a second location that is bilaterally symmetric relative to the first location; and determining a difference between the first perfusion value and the second perfusion value.

[0060] In one aspect, the present disclosure provides and includes a method for detecting tissue damage before it is visible on a patient's skin, comprising: measuring multiple perfusion values ​​at a single location at incremental times; calculating a slope between a most recent perfusion value and an immediately previous perfusion value; comparing this slope to a threshold; and determining that tissue damage is present if the slope exceeds the threshold.

[0061] In one aspect, the present disclosure provides and includes a method for detecting tissue damage before it is visible on a patient's skin, comprising: measuring multiple perfusion values ​​at multiple locations at incremental times; calculating a Δ value for each of the multiple perfusion values; calculating a slope between a latest Δ value and an immediately previous Δ value; comparing this slope to a threshold; and determining that tissue damage is present if the slope exceeds the threshold.

[0062] In one aspect, the present disclosure provides and includes a method for detecting tissue damage before it is visible on a patient's skin, comprising: measuring multiple perfusion values ​​at multiple locations at multiple incremental times; calculating a Δ value for each of the multiple perfusion values; calculating a derivative between the most recent Δ value and the immediately previous Δ value; comparing this derivative to a threshold; and determining that tissue damage is present if the derivative exceeds the threshold.

[0063] In one aspect, the present disclosure provides and includes a method for detecting tissue damage before it is visible on a patient's skin, the method comprising: measuring multiple perfusion values ​​at a single location at each of a plurality of incremental times; calculating a perfusion delta value for each incremental time; fitting a curve to a predetermined number of nearest perfusion delta values; calculating the curvature of the fitted curve; comparing this curvature to a threshold; and determining that tissue damage is present if the curvature exceeds the threshold.

[0064] In one aspect, the present disclosure provides and includes a method of detecting tissue damage before it is visible on a patient's skin, comprising: measuring multiple SpO2 values ​​at a single location at incremental times; calculating a slope between a latest SpO2 value and an immediately previous SpO2 value; comparing this slope to a threshold; and determining that tissue damage is present if the slope exceeds the threshold.

[0065] In one aspect, the present disclosure provides and includes a method of detecting tissue damage before it is visible on a patient's skin, comprising: measuring multiple SpO2 values ​​at a single location at incremental times; calculating a derivative between a most recent SpO2 value and an immediately previous SpO2 value; comparing the derivative to a threshold; and determining that tissue damage is present if the derivative exceeds the threshold.

[0066] In one aspect, the present disclosure provides and includes a method of detecting tissue damage before it is visible on a patient's skin, the method comprising: measuring a plurality of SpO2 values ​​at a single location at each of a plurality of incremental times; calculating an average for each incremental time; fitting a curve to the average of a predetermined number of recent SpO2 values; calculating the curvature of the fitted curve; comparing this curvature to a threshold; and determining the presence of tissue damage if the curvature exceeds the threshold. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] Various aspects of the present disclosure are described herein with reference to the accompanying drawings, by way of example only. With specific reference now to the drawings in detail, it is emphasized that the details shown are exemplary only and serve to facilitate an illustrative discussion of aspects of the present disclosure. In this regard, considering the description and drawings, both individually and together, one skilled in the art will readily understand how aspects of the present disclosure may be practiced.

[0068] Figure 1 The tissue surrounding the burn is depicted.

[0069] Figure 2A and 2B Depicts a flap created as part of breast reconstruction surgery.

[0070] Figure 3 Representative graphs of the absorption spectra of oxygenated and deoxygenated hemoglobin.

[0071] Figure 4 Depicted is a block diagram of an example perfusion measurement device according to the present disclosure.

[0072] Figure 5 Depicted are exemplary configurations of perfusion measurement devices according to the present disclosure.

[0073] Figure 6 A cross section of tissue is depicted showing how emitted light is reflected by the tissue in accordance with the present disclosure.

[0074] Figure 7 Depicted are transmitted and detected signals of an example system according to the present disclosure.

[0075] Figure 8 Depicted is the path of reflected light with a wide-angle source in accordance with the present disclosure.

[0076] Figure 9 Depicts a similar Figure 8 The transmitted signal and the detected signal of the system.

[0077] Figure 10A and 10B Depicted are detected signals of light reflected from oxygenated and deoxygenated hemoglobin in accordance with the present disclosure.

[0078] Figure 11A and 11B Depicted are detected signals of light reflected from oxygenated and deoxygenated hemoglobin along a line on a wound in accordance with the present disclosure.

[0079] Figure 11C According to the present disclosure Figure 11A and 11B A graph of the comparison points of the curves.

[0080] Figure 11D Depicts an example wound and Figure 11C An exemplary diagram of a measurement line of a graph.

[0081] Figure 11E Depicted is an example graph of perfusion sum values ​​taken across another wound in accordance with the present disclosure.

[0082] Figure 12A 、 12B , 12C and 12D depict examples of the disclosed device according to the present disclosure.

[0083] Figure 13 is a flow chart of an exemplary method of perfusion measurement according to the present disclosure.

[0084] Figure 14 An example of an overall process for selecting treatment for a wound based on perfusion measurements according to the present disclosure is depicted, where the time period of the process is from the admission of a patient to a nursing facility to the patient's discharge.

[0085] Figure 15 is an illustration of a process for selecting a level of intervention and monitoring based on the amount by which a delta value exceeds a threshold, wherein the delta value is derived from a perfusion measurement, in accordance with the present disclosure.

[0086] Figure 16 is an example of a workflow guidance matrix according to the present disclosure, where the current intervention level and the new delta value are used to select a new intervention level.

[0087] Figure 17 is an example graph of delta values ​​over time at a single wound location for a single patient in accordance with the present disclosure.

[0088] Figure 18A and 18Bis an example of a method of mapping a tissue injury site according to the present disclosure.

[0089] Figure 19A is an example of a currently recommended treatment decision pathway for preventing pressure ulcers in hospital patients using a combination of risk assessment and visual assessment.

[0090] Figure 19B is an example of a current enhanced treatment decision pathway currently being implemented in some healthcare settings for pressure ulcer prevention.

[0091] Figure 20 is an example flow chart according to the present disclosure illustrating how a device for evaluating blood perfusion in tissue beneath a patient's skin can be used in a standalone procedure to prevent pressure ulcers.

[0092] Figure 21 is an example flow chart according to the present disclosure showing how a device for evaluating blood perfusion in tissue beneath a patient's skin can be used as an aid to further improve Figure 19B Enhanced treatment decision-making pathways.

[0093] Figure 22A An example of a pair of bilaterally symmetrical locations on the sacral region according to the present disclosure is provided.

[0094] Figure 22B An example of a pair of bilaterally symmetrical locations on the soles of both feet according to the present disclosure is provided.

[0095] Figure 22C An example of a pair of bilaterally symmetrical locations on the sides and soles of the feet according to the present disclosure is provided.

[0096] Figure 23A Shown are locations on the left and right feet for perfusion measurements according to the present disclosure.

[0097] Figure 23B is a graph of perfusion values ​​associated with known relative positions for identifying bilaterally symmetric locations in accordance with the present disclosure.

[0098] Figure 24 An integrated system for measuring, evaluating, storing, and transferring perfusion values ​​according to the present disclosure is depicted.

[0099] Figure 25 Depicted are perfusion values ​​over time for patients at risk for developing pressure ulcers according to the present disclosure.

[0100] Figure 26 Depicted are perfusion delta values ​​over time for patients who developed pressure ulcers in accordance with the present disclosure.

[0101] Figure 27Depicted are illustrative perfusion and delta values ​​over time for a patient who developed a pressure ulcer in accordance with the present disclosure.

[0102] Figure 28 Depicted are example perfusion delta values ​​over time for a patient who developed a pressure ulcer on the heel according to the present disclosure.

[0103] Figure 29A 、 29B , 29C and 29D show various pressure points at different locations on the patient's body. DETAILED DESCRIPTION

[0104] This description is not an exhaustive list of all the different ways in which the present disclosure may be implemented or all the features that may be added to the present disclosure. For example, features shown with respect to one embodiment may be incorporated into another embodiment, and features shown with respect to a particular embodiment may be deleted from that embodiment. Therefore, the present disclosure contemplates that in some embodiments of the present disclosure, any feature or combination of features set forth herein may be excluded or omitted. In addition, in light of the present disclosure, various modifications and additions to the various embodiments suggested herein will be apparent to those skilled in the art and are within the scope of the present disclosure. In other cases, well-known structures, interfaces, and processes are not shown in detail so as not to unnecessarily obscure the present invention. No part of this specification should be construed as a negation of any part of the full scope of the present invention. Therefore, the following description is intended to illustrate some specific embodiments of the present disclosure, rather than to exhaustively indicate all permutations, combinations, and variations thereof.

[0105] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. The terms used in the description of the present disclosure are only for the purpose of describing specific aspects or embodiments and are not intended to limit the present disclosure.

[0106] All publications, patent applications, patents, and other references cited herein are incorporated herein by reference in their entirety for the teachings relevant to the sentence and / or paragraph in which the reference appears. References to techniques employed herein are intended to refer to techniques commonly understood in the art, including modifications to those techniques or substitutions of equivalent techniques that are apparent to those skilled in the art.

[0107] Unless the context indicates otherwise, in particular, the various features of the present disclosure may be used in any combination. In addition, the present disclosure also contemplates that, in some embodiments of the present disclosure, any feature or combination of features set forth herein may be excluded or omitted.

[0108] The method disclosed herein includes and comprises one or more steps or actions for realizing the described method.Without departing from the scope of the present disclosure, method steps and / or actions can be interchanged with each other.In other words, unless the correct operation of the embodiment requires specific steps or action sequence, otherwise without departing from the scope of the present disclosure, the order and / or purposes of specific steps and / or actions can be modified.

[0109] As used in the description of the present disclosure and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

[0110] As used herein, "and / or" refers to and encompasses any and all possible combinations of one or more of the associated listed items, as well as the lack of a combination when interpreted in the alternative ("or").

[0111] As used herein, the terms "about" and "approximately" when referring to measurable values ​​such as length, frequency, or perfusion values ​​are intended to encompass variations of ±20%, ±10%, ±5%, ±1%, ±0.5%, or even ±0.1% of the specified amount.

[0112] As used herein, phrases such as "between X and Y" and "between about X and Y" should be interpreted to include X and Y. As used herein, phrases such as "between about X and Y" mean "between about X and about Y," and phrases such as "about X to Y" mean "about X to about Y."

[0113] As used herein, the term "exemplary" is used to mean serving as an example, instance, or illustration. Any embodiment or aspect described as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments or aspects, nor is it intended to preclude equivalent structures and techniques known to those of ordinary skill in the art. Rather, the use of the word exemplary is intended to present concepts in a concrete manner, and the disclosed subject matter is not limited by such examples.

[0114] As used herein, the term "patient" includes human and animal subjects.

[0115] As used herein, the term "skin" refers to the surface of a patient's body.

[0116] As used herein, the term "tissue" includes multiple layers of a patient's body, starting from the stratum corneum, and includes additional deeper structures such as the epidermis, dermis, and a portion of the deeper tissue including blood vessels. In one aspect, tissue does not include the outermost surface of the patient's body.

[0117] As used herein, the term "wound" refers to damaged or injured tissue that may or may not be visible on the surface of the skin. A wound may be open or closed. A wound may result from a surgical procedure. A wound may be a burn wound. In one aspect, the wound is a pressure sore. In a further aspect, the pressure sore is subcutaneous. In one aspect, a pressure sore is a pressure sore caused by prolonged use of a medical device, such as, for example, a mask, tube, or strap. In one aspect, the wound is a diabetic foot ulcer. In one aspect, the wound is a vascular ulcer.

[0118] As used herein, the term "increment" refers to the calculated difference between two values ​​that are derived from measurements taken at about the same time from a subject. In one aspect, each value is the summed value calculated from measurements taken at about the same time. In one aspect, when measurements are taken within about an hour, such as less than about 30 minutes, less than about 20 minutes, less than about 10 minutes, less than about 5 minutes, less than about 4 minutes, less than about 3 minutes, less than about 2 minutes, less than about 1 minute, or less than about 30 seconds, the measurements are taken at about the same time.

[0119] As used herein, the term "time increment" refers to the calculated difference between two values, which are derived from measurements obtained at different times from a subject. On the one hand, each value is an average value calculated based on measurements obtained at approximately the same time. On the one hand, each value is a summed value calculated based on measurements obtained at approximately the same time. On the one hand, when measurements are spaced apart by greater than about one hour, such as greater than about 2 hours, such as greater than about 3 hours, such as greater than about 4 hours, such as greater than about 5 hours, such as greater than about 6 hours, such as greater than about 8 hours, or such as greater than about 10 hours, the measurements are obtained at approximately the same time.

[0120] As used herein, the variables "K," "L," "M," and "N" are non-negative integers.

[0121] As used herein, the term "anatomy specific" refers to applying a clinical intervention to the same location where a certain perfusion or SpO2 measurement is taken.

[0122] As used herein, a "system" may be a collection of devices that communicate with each other by wire or wireless communication.

[0123] As used herein, "bilaterally symmetrical" refers to a pair of locations that are approximately equidistant from a line of symmetry.

[0124] As used herein, the term "camera" includes any device that captures independent information about a plurality of points distributed over a two-dimensional area without contacting the points.

[0125] As used herein, the term "light" refers to electromagnetic energy having a wavelength in the range of 1 picometer to 1 meter. In one aspect, this range is 1 nanometer to 1 millimeter, encompassing "ultraviolet," "visible," and "infrared" light. In one aspect, this range is 10-390 nanometers, which is generally considered to be "ultraviolet" light. In one aspect, this range is 390-700 nanometers, which is generally considered to be "visible" light. In one aspect, this range is 700 nanometers to 1 millimeter, which is generally considered to be "infrared" radiation. In one aspect, this range is 700-900 nanometers, which is generally considered to be "near-infrared" radiation. In one aspect, this light can be a narrow band of wavelengths around a specific wavelength. In one aspect, the specific wavelength is 760 and / or 830 nanometers.

[0126] In this document, identifying light with a specific wavelength is synonymous with identifying light with a specific frequency because wavelength and frequency are uniquely related. References to the frequency of light are considered equivalent and interchangeable with references to the wavelength of the same light.

[0127] As used herein, the term "method" includes a series of activities, e.g., steps. In some embodiments, the steps must be performed in a specific order, while in other embodiments, the order of the activities can be interchanged. "Method" is considered equivalent to and interchangeable with "process." In some embodiments, one or more disclosed steps are omitted.

[0128] Perfusion and oxygenation measurements

[0129] Figure 1 Depicted is tissue surrounding a burn 102 of patient tissue 100. Tissue 100 has a surface epidermis layer 110, a dermis layer 120, and a subcutaneous layer 130. Blood vessels 180 in layer 130 connect to arterioles 182 that penetrate layers 120 and 110.

[0130] Burn 102 has a central region 150, which is the "necrotic zone," consisting primarily of dead tissue with a low water content. Surrounding region 150 is a region called the "stasis zone" 160, which is characterized by decreased tissue perfusion. The tissue in region 160 is potentially salvageable and is of particular interest to clinicians because it is the primary area of ​​focus in burn treatment. The next region, 170, is the hyperemic zone, where tissue perfusion is increased due to vasodilation caused by the local production of inflammatory mediators in region 170.

[0131] Figure 2A and 2B Depicted is a skin flap 240 created as part of breast reconstruction surgery. In this example, a portion of skin 210 is removed from the back above the latissimus dorsi muscle 220. Figure 2A The skin 210 is placed at position 240 to provide an additional surface to cover the implant 230, as shown. Figure 2B shown. Figure 2B Position 222 in FIG. 2 indicates the location from which flap 210 is removed.

[0132] Figure 3 300 is a representative graph of the absorption spectra of oxygenated hemoglobin 310 and deoxygenated hemoglobin 312. Oxygenation curve 310 has a local peak 320 at 760 nanometers, which creates a difference between the local maxima of curve 310 and curve 312 at this wavelength. At 830 nanometers, curve 310 has a local minimum 322, which also creates a local maximum in the difference between curves 310 and 312. Lasers emitting light with wavelengths in the 760-830 nanometer range can typically be used.

[0133] Figure 4 A block diagram of an example perfusion measurement device 400 according to the present disclosure is depicted. The device 400 includes a processor 440 connected to a display 410 and a user interface 480. The processor 440 is also coupled to a memory 450, a communication module 460, a transmitter 420, and a receiver 430.

[0134] In one aspect, memory 450 is non-volatile and contains instructions that, when loaded into and executed on processor 440 , cause processor 440 to perform one or more steps of a process.

[0135] In one aspect, the transmitter 420 is configured to transmit light, and the receiver 430 is configured to detect the light. In one aspect, the receiver 430 provides a signal to the processor 440, the signal including information about the received light. In one aspect, the information includes one or more data selected from the group consisting of: an intensity value of the detected light, a wavelength of the detected light, a timing of the detected light, and a duration of the detected light.

[0136] In one aspect, the transmitter 420 and / or the receiver 430 include an optical filter ( Figure 4 In one aspect, there are multiple emitters 420 and / or multiple receivers 430 that transmit and detect light of the same wavelength or at different frequencies. For example, a first emitter 420 emits 760 nanometer light, while a second emitter 420 emits 830 nanometer light. In one aspect, a single emitter 420 emits both 760 nanometer light and 830 nanometer light. For example, a first receiver 430 detects 760 nanometer light, while a second receiver 430 detects 830 nanometer light. In one aspect, a single receiver detects both 760 nanometer light and 830 nanometer light.

[0137] Figure 5An exemplary configuration of a perfusion measurement device 500 according to the present disclosure is depicted. The device 500 includes a substrate 502 to which a transmitter 501 and a plurality of receivers 510, 512, 514, 516, 518, and 520 are attached. The receiver 510 is spaced apart from the transmitter 501 by a first distance D1, while the receivers 510 and 512 are spaced apart by a second distance D2. In one aspect, the substrate 502 is flexible, such as Figure 5 In another aspect, substrate 502 is rigid and / or includes rigid elements.

[0138] Figure 6 A schematic cross-section of tissue 601 is depicted, illustrating how light emitted by emitter 610 is reflected by tissue 601, in accordance with the present disclosure. Light 612A is emitted at a first intensity. A portion of light 612A is reflected at a first depth as light 614A, while the remainder continues as light 612B. Similarly, a portion of light 612B is reflected at a second depth as light 614B, while the remainder continues as light 612C. In this example, a portion of light 612C is reflected as light 614C, while the remainder is lost in the deeper layers of tissue 601.

[0139] Still refer to Figure 6 Receivers 620, 622, and 624 are positioned at a distance from transmitter 610 so that they receive light 614A, 614B, and 614C, respectively. The intensity of each of light 614A, 614B, and 614C includes information about the tissue along the entire corresponding path from transmitter 610 to a particular receiver. In one aspect, information about the portion of the path of light 612B that is below light 612A and above light 612C is extracted by comparing information about the light detected by receiver 622 with one or both of light 614A and 614C received by receivers 620 and 624. In one aspect, this comparison is performed by subtracting the intensity of light received by receiver 620 from the intensity of light received by receiver 622. In one aspect, the information to be compared includes the intensity of one or more of light 614A, 614B, and 614C.

[0140] Figure 7 7. Depicted is a transmitted signal 710 and detected signals 720, 730, and 740 of an example system 700 according to the present disclosure. In this example, signal 720 is detected by a first receiver and has a peak value 724, signal 730 is detected by a second receiver and has a peak value 734, and signal 740 is detected by a third receiver and has a peak value 744. Figure 7As shown, peaks 724, 734, and 744 are time-shifted from the emitted pulses relative to the path length of the light from the emitter to the respective receiver. In this example, the waveforms of signals 720, 730, and 740 are shaped to reflect the detection of light traveling on multiple different paths from the emitter to the respective receiver.

[0141] In one aspect, time windows 722, 732, and 742 are applied to signals 720, 730, and 740 to detect only light that has traveled along a defined path from the transmitter to the receiver. Figure 7 ) is applied on a single signal to capture information about light that has traveled on different paths.

[0142] Figure 8 Depicted are example paths 812A, 812B, and 812C of reflected light with a wide-angle source in emitter 810, in accordance with the present disclosure. The wide-angle source emits light in a solid angle, such as a 30-degree cone. In one aspect, this cone can be oriented vertically, i.e., perpendicular to the skin, while in another aspect, the cone can be at an angle to the skin. In one aspect, the emitted light can be asymmetric about an axis.

[0143] Light beams 812A, 812B, and 812C are each emitted at a different angle. At an example depth 830, such as at the bottom of the dermis 120, light beams 814A, 814B, and 814C are reflected in a scattered manner from respective light beams 812A, 812B, and 812C toward a common receiver 820. Similarly, at a depth 840, such as at the bottom of the subcutaneous layer 130, light beams 816A, 816B, and 816C are reflected toward the same receiver 820. The light detected by receiver 820 contains temporal and intensity information about the light that has traveled along multiple paths from emitter 810.

[0144] Figure 9 Depicts a similar Figure 8 FIG2 shows an example of a system transmitting a signal 910 and detecting signals 914A and 916C. In this example, the transmitter transmits a light pulse 940 comprising light at two frequencies. Light at the first wavelength 914A is detected as pulse 944A, and light at the second wavelength is detected as pulse 946C. In one aspect, the timing of pulses 944A and 946A is adjusted before being added together. In another aspect, the timing of pulses 944A and 946A is not adjusted before being added together.

[0145] In one aspect, signals 914A and 916C are added together to form signal 920, which represents the timing and intensity of light reflected from oxygenated and deoxygenated hemoglobin.

[0146] Figure 10A and10B Depicted are detected signals of light reflected from oxyhemoglobin 1020 and deoxyhemoglobin 1010 at various points in a wound in accordance with the present disclosure. Figure 10A is a representation of a real continuous signal, and Figure 10B It is a representation of a calculation performed by taking measurements at discrete points on the same line.

[0147] exist Figure 10B , at location 1030, white dot 1050 is the intensity ratio of the oxygenated to deoxygenated wavelengths and is plotted with reference to the left scale "Oxygenation." In one aspect, the intensity ratio of the oxygenated to deoxygenated wavelengths can be converted to an SpO2 value, indicating the percentage of oxygenated blood at the local site. At the same location 1030, black dot 1060 is the sum of the intensities of the two wavelengths and is plotted with reference to the right scale "Perfusion." The sum 1060 provides information indicating fair-to-poor perfusion at location 1030, giving a different perspective than the ratio 1050, which indicates a higher oxygenation level. In practice with existing ratio methods, it is generally believed that high levels of oxygenation are a sign of good perfusion, and vice versa. However, in this example, the data obtained using the method of the present disclosure shows that the perfusion at the site with high levels of oxygenation is actually poor, while the perfusion at the site with low levels of oxygenation is actually relatively good.

[0148] Still refer to Figure 10B , at location 1040, the oxygenation ratio 1052 indicates that the oxygenation level is less than optimal, while the perfusion sum 1062, which is the sum of the intensities of the two wavelengths, indicates that perfusion is good. Again, providing information about the total amount of oxygenated and deoxygenated hemoglobin gives a different perspective than a simple ratio of one to the other.

[0149] Figure 11A and 11BDepicted are detected signals of light reflected from oxygenated hemoglobin 1101 and deoxygenated hemoglobin 1102 along a line of a wound in accordance with the present disclosure. Points 1120, 1122, 1124, 1126, and 1128 are five locations identified along the line. In one aspect, a line can be drawn along the wound in any direction. In one aspect, any number of positions can be identified along the measurement line, for example, up to 100 positions, such as up to 95 positions, up to 90 positions, up to 85 positions, up to 80 positions, up to 75 positions, up to 70 positions, up to 65 positions, up to 60 positions, up to 55 positions, up to 50 positions, up to 45 positions, up to 40 positions, up to 35 positions, up to 30 positions, up to 25 positions, up to 20 positions, up to 15 positions, up to 10 positions, up to 9 positions, up to 8 positions, up to 7 positions, up to 6 positions, up to 5 positions, up to 4 positions, up to 3 positions, up to 2 positions, or 1 position. In one aspect, the positions identified along the line can be approximately equidistantly spaced. In one aspect, the positions identified along the line can be unevenly spaced. In one aspect, subsets of the positions identified along the line can be approximately equidistantly spaced. In one aspect, subsets of the positions identified along the line can be unevenly spaced. In one aspect, a plurality of lines can be drawn along the wound for measurement. In one aspect, up to 100 lines can be drawn for measurement, such as up to 95 lines, up to 90 lines, up to 85 lines, up to 80 lines, up to 75 lines, up to 70 lines, up to 65 lines, up to 60 lines, up to 55 lines, up to 50 lines, up to 45 lines, up to 40 lines, up to 35 lines, up to 30 lines, up to 25 lines, up to 20 lines, up to 15 lines, up to 10 lines, up to 9 lines, up to 8 lines, up to 7 lines, up to 6 lines, up to 5 lines, up to 4 lines, up to 3 lines, up to 2 lines, or 1 line. In one aspect, the lines drawn along the wound can have approximately the same angle between them. In one aspect, the lines drawn along the wound can have different angles between them. In one aspect, a subset of the lines drawn along the wound can have approximately the same angle between them. In one aspect, subsets of lines drawn along the lesion can have different angles between them.

[0150] Figure 11C According to the present disclosure Figure 11A and 11BGraph 1100 shows comparison points 1120, 1122, 1124, 1126, and 1128 of curves 1101 and 1102. White points 1130, 1132, 1134, 1136, and 1138, connected by reference line 1131, are oxygenation ratios (ratios of the values ​​of curve 1101 to curve 1102 at the specified points) and are plotted with reference to the left vertical axis "Oxygenation." Black points 1140, 1142, 1144, 1146, and 1148, connected by reference line 1141, are the sum of the values ​​of curves 1101 and 1102 and are plotted with reference to the right vertical axis "Perfusion."

[0151] In one aspect, when assessing the status of a wound by examining lines 1131 and 1141, the clinician can make different assessments of the size and condition of the wound based on the shapes of lines 1131 and 1141. In this example, the perfusion information of line 1141 indicates that the wound is smaller and narrower than that of line 1131. If the clinician were to continue attempting to remove necrotic tissue from area 150, then reference would be made to the following example: Figure 1 If guided by wire 1131, the clinician may be able to remove more tissue than if guided by wire 1141. This may result in the unintended removal of some tissue in zone of stasis 160, thereby potentially enhancing wound healing and the final state.

[0152] In this example, the outermost measurement point (at Figure 11D 1140) is outside the affected area of ​​the wound, and none of the other measurements is greater than the value of measurement 1140, indicating that no measurements were taken in the hyperemic area. Figure 11C Line 1150 represents the maximum summed value of the measurements taken at the two frequencies in this example, which is summed value 1140 in this example. If the line of measurement points extends beyond the visible area of ​​the wound lesion, the outermost measurement point may overlap unaffected healthy tissue. Measurements taken at a point above the healthy tissue form a baseline value against which measurements in the affected area can be compared. Similarly, the summed value of the measurements taken at the two frequencies at a point above the healthy tissue forms the baseline summed value. Because damaged tissue inherently has perfusion that differs from normal perfusion, comparing the summed value at a point in the affected area around the wound with the summed value of healthy tissue improves the accuracy of the assessment, whether it is increased perfusion in areas of hyperemia or decreased perfusion in areas of stasis or necrosis. By comparing the two summed values ​​by the same person using the same equipment at approximately the same time, "common mode" factors that can affect all measurements are eliminated, such as whether the patient is active, inactive, dehydrated, or experiencing general blood loss. Comparing the affected area with the healthy area provides a better understanding of the extent of the damage.

[0153] There is a delta value 1152 between this maximum sum value and the sum value 1142. There are other delta values ​​1154, 1156, and 1158 between the maximum sum value 1150 and the respective sum values ​​1144, 1146, and 1148.

[0154] Figure 11E An example curve 1107 of perfusion summation values ​​obtained from another wound (not shown) according to the present disclosure is depicted. A summation value 1172 has been obtained from known healthy tissue. A summation value 1174 is obtained closer to the wound, and its increased value compared to 1174 indicates that this location is within a hyperemic zone. A value close to zero for summation value 1176 indicates that it may be within a necrotic zone. Values ​​1178 and 1180, which are lower than 1172 but higher than 1176, indicate that these may be within a stasis zone. The shape of curve 1182 provides guidance to the clinician regarding the nature of the underlying tissue at and between the measurement points.

[0155] If the measurement location is within a hyperemic area, the sum value may be higher than that of healthy tissue. Figure 11C The "baseline" value of line 1150 in is chosen to be the outermost point, such as Figure 11D 1140, or from a point specifically selected as a location above unaffected healthy tissue. In one aspect, the baseline value to which the other sum values ​​are compared is a value associated with known healthy tissue, which may not be the maximum sum value.

[0156] In one aspect, a user can take repeated measurements to map areas of hyperemia, as indicated by a summed value (e.g., perfusion) that is higher than a baseline value for known healthy tissue. The location can be captured manually (e.g., by marking on a picture or photograph of the wound) or via a position sensing system (e.g., using a 3D accelerometer-based position determination system). Alternatively, the perfusion measurement device can incorporate a marking capability so that the user can trigger a marker to be applied to the skin. The user can do this manually. In one aspect, the perfusion measurement device can automatically apply the marker when the summed value exceeds a threshold. A threshold can be set when taking perfusion measurements of known healthy tissue. In one aspect, the threshold can be directly input by the user.

[0157] exist Figure 11E In the example of FIG. 1 , the baseline value will be selected as value 1172, and delta values ​​will be calculated for the sum values ​​1174, 1176, 1178, and 1180. In one aspect, the delta values ​​will be reported as positive values ​​for point 1174 and negative values ​​for points 1176, 1178, and 1180. In one aspect, the polarity of the delta values ​​will be reversed. In one aspect, only the absolute value of delta is reported.

[0158] In one aspect, multiple measurements are taken at the selected position at each selected wavelength. In one aspect, according to the present disclosure, the multiple measurements taken at the selected position at each selected wavelength are averaged prior to summing. In one aspect, each set of measurements consisting of measurements taken at the selected position at all selected wavelengths is first summed, and then the average sum value is determined by averaging the sums obtained in each set of measurements.

[0159] On the one hand, the Δ value is determined by subtracting the sum value from the baseline value. On the one hand, the baseline value is selected according to the method of paragraph

[0153] . On the one hand, the baseline value is calculated by the average of the sum values ​​obtained at the location outside the wound. On the one hand, the baseline value is calculated by the average of all sum values ​​obtained inside and outside the wound. On the one hand, the Δ value is determined by subtracting the average sum value at a certain position from the baseline value. On the one hand, the Δ value is determined by subtracting the minimum sum value at a certain position from the baseline value. On the one hand, the Δ value is determined by subtracting the minimum sum value at a certain position from the maximum sum value. On the one hand, the percentage value of each sum value relative to the maximum sum value in a series of sum values ​​is further determined.

[0160] Figure 11D Depicts an example wound 1105 and Figure 11C Points 1140, 1142, 1144, 1146, and 148 correspond to Figure 11A and 11B The positions of 1120, 1122, 1124, 1126, and 1128 are shown. The necrotic region 1164 and the hyperemic region 1160 reflect the information provided by line 1141. Region 1162 schematically illustrates a necrotic comparison region associated with the oxygenation line 1131, which is larger and wider than the perfusion guide region 1164.

[0161] Figure 12A 、 12B , 12C and 12D depict examples of the disclosed device according to the present disclosure.

[0162] Figure 12A 1 is an example handheld device 1200 having a single transmitter 1202 and (in this example) two receivers 1204 disposed on opposite sides of the transmitter 1202. The transmitter 1202 and receivers 1204 are mounted on a rigid substrate.

[0163] Figure 12B An example bandage 1210 is depicted in which a transmitter 1202 and a receiver 1204 are provided on a flexible absorbent pad 1206 having an adhesive backing 1208 intended to secure the bandage in a fixed position on the patient's skin. Repeated measurements of reflected light by the receiver 1204 over time enable tracking of the condition of the wound.

[0164] Figure 12C A substrate 1210 is depicted with an array of emitters 1202 and receivers 1204 arranged in a grid. In one aspect, a single emitter 1202 is activated, and one or more of the surrounding receivers 1204 sense the reflected light. In one aspect, different emitters 1202 emit light of different wavelengths.

[0165] Figure 12D A system 1230 is depicted that includes one or more emitters 1236 that emit a light beam 1238 and one or more receivers 1232 having a field of view 1234. In one aspect, the receiver 1232 is an imaging camera that optically detects the intensity of light reaching the skin surface surrounding a wound 1250. In one aspect, the emitters 1236 emit light of different wavelengths. In one aspect, the emitters 1236 are activated at different and non-overlapping times, and the receivers 1232 can detect reflected light of either wavelength.

[0166] Figure 13 1300 is a flow chart of an exemplary method for perfusion measurement according to the present disclosure. The process proceeds from start step 1302 to step 1304, where the amount of oxygenated and deoxygenated hemoglobin is measured at one or more depths below the skin. In one aspect, these measurements are derived by comparing signals from multiple receivers arranged around a single transmitter. In step 1306, which may be performed before or in parallel with step 1304, the location is determined. Step 1308 sums the measurements associated with oxygenated and deoxygenated hemoglobin. Step 1310 optionally adjusts the sum by comparing it with information about light reaching the receivers via alternate paths through the tissue. The original and adjusted values ​​are recorded in step 1312. If more readings are to be taken around the injury site, the process takes a "no" path 1316 at step 1314 and then returns to step 1304. If all measurements are complete, the process branches to "yes" path 1318 at step 1314 to step 1320, where a delta value is calculated as the difference between the highest perfusion value associated with healthy tissue and various other measurements around the common location. These delta values ​​are plotted at step 1322 and represent the perfusion degradation compared to a baseline of healthy tissue acquired at the same time and location by the same user using the same instrument for the same patient. The process terminates at step 1324, "End."

[0167] Choosing a strategy for tissue injury intervention using perfusion or oxygenation measurements

[0168] Figure 14Depicted is an overall process 1400 from admission to discharge from a nursing facility in accordance with the present disclosure for selecting a wound treatment strategy based on measured perfusion or oxygenation values ​​of blood in the tissue beneath the patient's skin. In one aspect, the wound is a pressure sore. In one aspect, a pressure sore is a pressure sore caused by prolonged use of a medical device, such as a mask, tube, or strap. In one aspect, the wound is a diabetic foot ulcer. In one aspect, the wound is a vascular ulcer. In one aspect, the wound is a burn wound. In one aspect, the nursing facility is selected from the group consisting of: a hospital, a rehabilitation facility, an assisted living facility, a residential care facility, a nursing home, a long-term care facility, a continuing care community, and an independent living community. In one aspect, the nursing facility can be the patient's home or other residence, and thus, the "admission" step 1402 will be the first assessment of the patient by a nurse or other caregiver in their home. In one aspect, the schedule of interventions and assessment intervals used in the home setting can be different from the corresponding interventions and intervals used in the hospital.

[0169] In one aspect, in process 1400, a newly admitted patient undergoes an intake assessment in step 1404 that includes: a visual inspection of a portion of the patient's skin; completion of at least a portion of a risk assessment protocol that assesses one or more of nutrition, mobility, physical activity, strength, and communication ability; and taking blood perfusion measurements at one or more locations on the patient's skin. In one aspect, the perfusion measurements can include taking multiple perfusion measurements at a single "location" on the patient's skin. In one aspect, the SpO2 value is determined by converting the intensity ratio of the oxygenated and deoxygenated wavelengths measured during the perfusion measurement. In one aspect, the SpO2 value is considered a location rather than a single point, such that perfusion measurements can be taken at spatially separated points within the location. For example, a "heel" location includes the medial, lateral, and posterior surfaces around the heel and the posterior portion of the sole of the foot.

[0170] In one aspect, once the assessment step is complete, a determination is made in step 106 as to whether the patient's readings are abnormal, i.e., whether the combination of the results of the various elements of the assessment indicates that the patient has or is at risk of developing further wound tissue damage. Each element of the assessment can have a separate risk level criterion, such as a scoring system with a threshold indicating unacceptable risk. In one aspect, there are protocols for combining criteria to generate a composite parameter that can be used to select a level of intervention.

[0171] In one aspect, if the patient is determined to be at an acceptable risk level, the process proceeds to step 1408, which implements the lowest level of intervention, referred to herein as "Level Zero" or "Level 0." Proceeding to steps 1410 and 1412, the patient is re-evaluated in step 1414 using at least the perfusion or oxygenation measurement protocol at a frequency associated with Level 0, or at intervals otherwise. The process 1400 then loops back to step 1406 to evaluate the results of the perfusion or oxygenation measurement performed in step 1414.

[0172] In one aspect, if it is determined in step 1406 that the patient has an abnormal reading, the process moves to step 1422, which implements a higher level of intervention. In one aspect, there is a hierarchy of defined levels of intervention, with each level implementing a more intensive intervention than the next lower level. In one aspect, each level also has a defined monitoring interval or frequency, indicating how often a set of perfusion or oxygenation measurements should be taken, with higher levels generally having shorter intervals. In this example, the process has been defined by the hospital or other governing organization so that one level is set to Level 1 intervention at this point. In another aspect, step 1422 may implement Level 2 or higher levels of intervention. The process now enters a new loop starting at step 1430, in which the patient will be monitored at a frequency of N levels, where N ranges from 1 to n, n being the highest defined level of intervention and monitoring.

[0173] In one aspect, at step 1434, the patient's medical history is evaluated to determine if their condition is improving. If the patient's condition is improving (e.g., as evidenced by a decrease in the delta value of the perfusion measurement), the process proceeds to step 1442. In this example, step 1442 continues to implement the current intervention level, and the process loops through steps 1440 through steps 1430-1432-1434-1442-1440 until the delta value drops below a threshold. In one aspect, in step 1442, as the delta value trends downward, the intervention level can be decreased based on the magnitude of the delta value. In one aspect, if the oxygenation measurement consistently maintains an oxygenation level of 95% or above, the patient's condition is improving.

[0174] On the one hand, if the patient does not show improvement in step 1434, the process proceeds to step 1438 where the level of intervention is increased, provided that the skin has not broken down, i.e., an open wound has not developed, in step 1436. If an open wound has developed, perfusion measurements will now be taken around the open wound in step 1444 to map inflammation or other precursors to wound expansion. The open wound itself is treated in step 1448, and this second cycle 1444-1446-1448-1450 continues until the wound closes, at which point the process returns to step 1430.

[0175] In one aspect, at any time during process 100, when a patient is discharged, the process proceeds to step 1418, where the patient's condition at the time of discharge or transfer is recorded. In one aspect, step 1418 includes taking a final set of perfusion measurements at one or more locations on the patient's body. In one aspect, a final set of oxygenation measurements is taken at one or more locations on the patient's body. In one aspect, these locations include sites that have not received intervention and have not been previously identified as at risk. In one aspect, this information is provided to the receiving caregiver. The patient is then discharged or transferred in step 120.

[0176] In one aspect, the present disclosure provides and includes a method for identifying and treating a patient requiring a wound intervention, the method comprising the steps of: assessing the patient's risk of tissue damage upon admission to a nursing facility, wherein the assessing step comprises: performing a first plurality of perfusion measurements in the patient; calculating a first Δ value based on a portion of the first plurality of perfusion measurements; determining whether the first Δ value exceeds a first threshold; if the first Δ value does not exceed the first threshold, applying a level 0 first intervention; if the first Δ value exceeds the first threshold, applying a level N first intervention, wherein N is an integer and the value of N is 1 or greater.

[0177] In one aspect, the present disclosure provides and encompasses a method for identifying and treating a patient requiring a wound intervention, the method comprising the steps of: assessing a patient's risk of tissue damage upon admission to a nursing facility, wherein the assessing step comprises: performing a first plurality of SpO2 measurements on the patient; determining whether any of the first plurality of SpO2 measurements is below a first threshold; administering a level 0 first intervention if the first plurality of SpO2 measurements is at or above the first threshold; administering a level N first intervention if any of the first plurality of SpO2 measurements is below the first threshold, wherein N is an integer and the value of N is 1 or greater. In one aspect, the first threshold SpO2 measurement is approximately 95%. In one aspect, the first threshold SpO2 measurement is approximately 95.5%, approximately 96%, approximately 96.5%, 97%, approximately 97.5%, or approximately 98%.

[0178] In one aspect, a first plurality of perfusion measurements is performed at and around one or more anatomical sites selected from the group consisting of: the patient's sternum, sacrum, heel, scapula, elbow, ear, and flesh over other bony prominences. In one aspect, a first plurality of perfusion measurements is performed at and around one or more anatomical sites at risk for tissue damage. In one aspect, a first plurality of perfusion measurements is performed at and around all anatomical sites at risk for tissue damage. Figure 29A 、 29B, 29C and 29D illustrate the location of tissue damage risk at various locations on a patient, shown as circles. In one aspect, a first plurality of perfusion measurements are taken at and around one or more anatomical sites in chronic contact with the medical device, the anatomical sites selected from the group consisting of: cheek, nose, chest, stomach, and lower abdomen. In one aspect, the first plurality of perfusion measurements are divided into subgroups for analysis based on the approximate location at which the measurements were taken. In one aspect, the first plurality of perfusion measurements are taken at locations located on one or more concentric circles centered about the anatomical site. In one aspect, the first plurality of perfusion measurements are taken at locations located on a straight line approximately equidistant from the anatomical site.

[0179] In one aspect, a first delta value is determined by a difference between a maximum perfusion value and a minimum perfusion value from a first plurality of collected perfusion measurements. In one aspect, the first delta value is determined by a difference between a maximum perfusion average of measurements taken at one location and a minimum perfusion average of measurements taken at a second location. In one aspect, the first delta value is determined for a portion of a first plurality of perfusion measurements, the first plurality of perfusion measurements consisting of a subset defined by the locations at which the measurements were taken. In one aspect, an average perfusion value at a location is obtained from two, three, four, five, six, seven, eight, nine, ten, or more perfusion values ​​measured at the location. In one aspect, the first delta value is determined by a difference between perfusion values ​​derived from measurements taken at two bilaterally symmetrical locations relative to a centerline.

[0180] In one aspect, a delta value can be calculated based on multiple perfusion measurements at a location or in close proximity to a particular location in a variety of ways. In one aspect, multiple perfusion measurements are taken on the skin in a predetermined pattern, and the delta value is calculated by subtracting the perfusion value associated with the predetermined location in the pattern from the maximum perfusion value taken at other locations in the pattern. In one aspect, multiple perfusion measurements are taken on the skin in a predetermined pattern, and the delta value is calculated by identifying the perfusion value associated with the predetermined location in the pattern and subtracting the maximum perfusion value taken at other locations in the pattern. In one aspect, an average perfusion value can be calculated from a portion of a set of perfusion values ​​generated from multiple perfusion measurements at a single location, and the delta value can be calculated as the maximum difference between the average and a single perfusion value for the same set. In one aspect, the delta value can be calculated as the ratio of the maximum perfusion value to the minimum perfusion value within a set of perfusion values.

[0181] In one aspect, the first threshold value can be about 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3. 3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.0, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, 5.0, 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8, 5.9, 6.0, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9, 7.0, 7.1, 7.2, 7.3, 7.4, or 7.5. In one aspect, the first threshold value can be in the range of 0.1 to 8.0, such as 0.1 to 1.0, 1.1 to 2.0, 2.1 to 3.0, 3.1 to 4.0, 4.1 to 5.0, 5.1 to 6.0, 6.1 to 7.0, 7.1 to 8.0, 0.1 to 7.5, 0.5 to 8.0, 1.0 to 7.0, 1.5 to 6.5, 2.0 to 6.0, 3.0 to 5.5, 3.5 to 5.0, or 4.0 to 4.5. In one aspect, the first threshold value can be scaled by a factor or multiple based on the values ​​provided herein. It should be understood that the threshold value is not limited by design, but rather, one of ordinary skill in the art will be able to select a predetermined value based on a given perfusion unit. In one aspect, the threshold values ​​of the present disclosure vary depending on the specific part of the patient's body on which the measurement is made or one or more characteristics of the patient, such as age, height, weight, family history, race, and other physical characteristics or medical conditions.

[0182] In one aspect, N ranges from 1 to 50, such as 1 to 2, 1 to 3, 1 to 4, 1 to 5, 1 to 6, 1 to 7, 1 to 8, 1 to 9, 1 to 10, 1 to 15, 1 to 20, 1 to 25, 1 to 30, 1 to 35, 1 to 40, or 1 to 45.

[0183] In one aspect, N is determined by the amount by which the first delta value exceeds a first threshold. In one aspect, the amount by which the delta value exceeds the threshold established for (N+1) is greater than the amount by which the delta value exceeds the threshold established for N. In one aspect, the amount by which the delta value exceeds the threshold established for (N-1) is less than the amount by which the delta value exceeds the threshold established for N.

[0184] In one aspect, a Level 1 (N=1) intervention is applied to a patient having a Δ value that exceeds a threshold by no more than 100% of the threshold, such as no more than 95% of the threshold, no more than 90% of the threshold, no more than 85% of the threshold, no more than 80% of the threshold, no more than 75% of the threshold, no more than 70% of the threshold, no more than 65% of the threshold, no more than 60% of the threshold, no more than 55% of the threshold, no more than 50% of the threshold, no more than 45% of the threshold, no more than 40% of the threshold, no more than 35% of the threshold, no more than 30% of the threshold, no more than 25% of the threshold, no more than 20% of the threshold, no more than 15% of the threshold, no more than 10% of the threshold, or no more than 5% of the threshold. In one aspect, a Level 1 intervention is applied to the location where the measurement is taken.

[0185] In one aspect, a Level 2 intervention (N=2) is applied to patients who have a Δ value that exceeds the threshold by no more than 150% of the threshold, such as no more than 145% of the threshold, no more than 140% of the threshold, no more than 135% of the threshold, no more than 130% of the threshold, no more than 125% of the threshold, no more than 120% of the threshold, no more than 115% of the threshold, no more than 110% of the threshold, no more than 100% of the threshold, no more than 95% of the threshold, no more than 90% of the threshold , no more than 85% of the threshold, no more than 80% of the threshold, no more than 75% of the threshold, no more than 70% of the threshold, no more than 65% of the threshold, no more than 60% of the threshold, no more than 55% of the threshold, no more than 50% of the threshold, no more than 45% of the threshold, no more than 40% of the threshold, no more than 35% of the threshold, no more than 30% of the threshold, no more than 25% of the threshold, no more than 20% of the threshold, no more than 15% of the threshold, no more than 10% of the threshold, or no more than 5% of the threshold. In one aspect, level 2 intervention is applied to the location where the measurement is taken.

[0186] In one aspect, a Level 3 intervention (N=3) is applied to patients who have a Delta value that exceeds the threshold by no more than 200% of the threshold, such as no more than 195% of the threshold, no more than 190% of the threshold, no more than 185% of the threshold, no more than 180% of the threshold, no more than 175% of the threshold, no more than 170% of the threshold, no more than 165% of the threshold, no more than 160% of the threshold, no more than 155% of the threshold, no more than 150% of the threshold, no more than 145% of the threshold, no more than 140% of the threshold, no more than 135% of the threshold, no more than 130% of the threshold, no more than 125% of the threshold, no more than 125% of the threshold, no more than 120 ... In one aspect, 3 levels of intervention are applied to the location where the measurement is taken.

[0187] In one aspect, a Level 4 intervention (N=4) is applied to patients who have a Delta value that exceeds the threshold by no more than 250% of the threshold, such as no more than 245% of the threshold, no more than 240% of the threshold, no more than 235% of the threshold, no more than 230% of the threshold, no more than 225% of the threshold, no more than 220% of the threshold, no more than 215% of the threshold, no more than 210% of the threshold, no more than 205% of the threshold, no more than 200% of the threshold, no more than 195% of the threshold, no more than 190% of the threshold, no more than 185% of the threshold, no more than 180% of the threshold, no more than 175% of the threshold, no more than 170% of the threshold, no more than 165% of the threshold, no more than 160% of the threshold, no more than 155% of the threshold, no more than 150% of the threshold, no more than 140% of the threshold, no more than 150% of the threshold, no more than 145% of the threshold, no more than 150 ... In one aspect, 4 levels of intervention are applied to the location where the measurement is taken.

[0188] In one aspect, 5 levels of intervention (N=5) are applied to patients who have a Δ value that exceeds the threshold by no more than 300% of the threshold, such as no more than 295% of the threshold, no more than 290% of the threshold, no more than 285% of the threshold, no more than 280% of the threshold, no more than 275% of the threshold, no more than 270% of the threshold, no more than 265% of the threshold, no more than 260% of the threshold, no more than 255% of the threshold, no more than 250 ... 245%, not more than 240% of the threshold, not more than 235% of the threshold, not more than 230% of the threshold, not more than 225% of the threshold, not more than 220% of the threshold, not more than 215% of the threshold, not more than 210% of the threshold, not more than 205% of the threshold, not more than 200% of the threshold, not more than 195% of the threshold, not more than 190% of the threshold, not more than 185% of the threshold, not more than 180% of the threshold, not more than 175% of the threshold, not more than 170% of the threshold 0%, not more than 165% of the threshold, not more than 160% of the threshold, not more than 155% of the threshold, not more than 150% of the threshold, not more than 145% of the threshold, not more than 140% of the threshold, not more than 135% of the threshold, not more than 130% of the threshold, not more than 125% of the threshold, not more than 120% of the threshold, not more than 115% of the threshold, not more than 110% of the threshold, not more than 100% of the threshold, not more than 95% of the threshold, not more than 90% of the threshold, not more than 100% of the threshold 85% or more of the threshold, 80% or less of the threshold, 75% or less of the threshold, 70% or less of the threshold, 65% or less of the threshold, 60% or less of the threshold, 55% or less of the threshold, 50% or less of the threshold, 45% or less of the threshold, 40% or less of the threshold, 35% or less of the threshold, 30% or less of the threshold, 25% or less of the threshold, 20% or less of the threshold, 15% or less of the threshold, 10% or less of the threshold, or 5% or less of the threshold. In one aspect, 5 levels of intervention are applied to the location where the measurement is taken.

[0189] In one aspect, 6 levels of intervention (N=6) are applied to patients who have a delta value that exceeds the threshold by no more than 350% of the threshold, such as no more than 345% of the threshold, no more than 340% of the threshold, no more than 335% of the threshold, no more than 330% of the threshold, no more than 325% of the threshold, no more than 320% of the threshold, no more than 315% of the threshold, no more than 310% of the threshold, no more than 305% of the threshold, no more than 300% of the threshold, no more than 295% of the threshold, no more than 290% of the threshold, no more than 285% of the threshold, no more than 300% of the threshold, no more than 315% of the threshold, no more than 310% of the threshold, no more than 305% of the threshold, no more than 300% of the threshold, no more than 295% of the threshold, no more than 290% of the threshold, no more than 285% of the threshold, no more than 290 ... 280% or less of the threshold, 275% or less of the threshold, 270% or less of the threshold, 265% or less of the threshold, 260% or less of the threshold, 255% or less of the threshold, 250% or less of the threshold, 245% or less of the threshold, 240% or less of the threshold, 235% or less of the threshold, 230% or less of the threshold, 225% or less of the threshold, 220% or less of the threshold, 215% or less of the threshold, 210% or less of the threshold, 205% or less of the threshold, 200% or less of the threshold, 19% or less of the threshold 5%, not more than 190% of the threshold, not more than 185% of the threshold, not more than 180% of the threshold, not more than 175% of the threshold, not more than 170% of the threshold, not more than 165% of the threshold, not more than 160% of the threshold, not more than 155% of the threshold, not more than 150% of the threshold, not more than 145% of the threshold, not more than 140% of the threshold, not more than 135% of the threshold, not more than 130% of the threshold, not more than 125% of the threshold, not more than 120% of the threshold, not more than 115% of the threshold, not more than 110% of the threshold, not more than the threshold In one aspect, 6 levels of intervention are applied to the location where the measurement is taken.

[0190] In one aspect, 7 levels of intervention (N=7) are applied to patients who have a Δ value that exceeds the threshold by no more than 400% of the threshold, such as no more than 395% of the threshold, no more than 390% of the threshold, no more than 385% of the threshold, no more than 380% of the threshold, no more than 375% of the threshold, no more than 370% of the threshold, no more than 365% of the threshold, no more than 360% of the threshold, no more than 355% of the threshold, no more than 350% of the threshold, no more than 345% of the threshold, no more than 340% of the threshold, no more than 335% of the threshold, no more than 330% of the threshold, no more than 325% of the threshold, no more than 340% of the threshold, no more than 350% of the threshold, no more than 365% of the threshold, no more than 370% of the threshold, no more than 380% of the threshold, no more than 39 ... 320%, not more than 315% of the threshold, not more than 310% of the threshold, not more than 305% of the threshold, not more than 300% of the threshold, not more than 295% of the threshold, not more than 290% of the threshold, not more than 285% of the threshold, not more than 280% of the threshold, not more than 275% of the threshold, not more than 270% of the threshold, not more than 265% of the threshold, not more than 260% of the threshold, not more than 255% of the threshold, not more than 250% of the threshold, not more than 245% of the threshold, not more than 240% of the threshold, not more than 235% of the threshold, not more than 230% of the threshold, not more than 225% of the threshold, not more than 225% of the threshold 0%, not more than 215% of the threshold, not more than 210% of the threshold, not more than 205% of the threshold, not more than 200% of the threshold, not more than 195% of the threshold, not more than 190% of the threshold, not more than 185% of the threshold, not more than 180% of the threshold, not more than 175% of the threshold, not more than 170% of the threshold, not more than 165% of the threshold, not more than 160% of the threshold, not more than 155% of the threshold, not more than 150% of the threshold, not more than 145% of the threshold, not more than 140% of the threshold, not more than 135% of the threshold, not more than 130% of the threshold, not more than 125% of the threshold, not more than 120% of the threshold , no more than 115% of the threshold, no more than 110% of the threshold, no more than 100% of the threshold, no more than 95% of the threshold, no more than 90% of the threshold, no more than 85% of the threshold, no more than 80% of the threshold, no more than 75% of the threshold, no more than 70% of the threshold, no more than 65% of the threshold, no more than 60% of the threshold, no more than 55% of the threshold, no more than 50% of the threshold, no more than 45% of the threshold, no more than 40% of the threshold, no more than 35% of the threshold, no more than 30% of the threshold, no more than 25% of the threshold, no more than 20% of the threshold, no more than 15% of the threshold, no more than 10% of the threshold, or no more than 5% of the threshold. In one aspect, 7 levels of intervention are applied to the location where the measurement is taken.

[0191] In one aspect, an 8-level intervention (N=8) is applied to patients having a delta value that exceeds the threshold by no more than 450% of the threshold, such as no more than 445% of the threshold, no more than 440% of the threshold, no more than 435% of the threshold, no more than 430% of the threshold, no more than 425% of the threshold, no more than 420% of the threshold, no more than 415% of the threshold, no more than 410% of the threshold, no more than 405% of the threshold, no more than 400% of the threshold, no more than 395% of the threshold, no more than 390% of the threshold, no more than 385% of the threshold, no more than 380% of the threshold, no more than 375% of the threshold, no more than 370% of the threshold, no more than 365% of the threshold, no more than 360% of the threshold, no more than 385% of the threshold, no more than 390% of the threshold, no more than 39 ... 355% or less of the threshold, 350% or less of the threshold, 345% or less of the threshold, 340% or less of the threshold, 335% or less of the threshold, 330% or less of the threshold, 325% or less of the threshold, 320% or less of the threshold, 315% or less of the threshold, 310% or less of the threshold, 305% or less of the threshold, 300% or less of the threshold, 295% or less of the threshold, 290% or less of the threshold, 285% or less of the threshold, 280% or less of the threshold, 275% or less of the threshold, 270% or less of the threshold, 265% or less of the threshold, 260% or less of the threshold, 255% or less of the threshold, 250% or less of the threshold, 240% or less of the threshold 5%, not more than 240% of the threshold, not more than 235% of the threshold, not more than 230% of the threshold, not more than 225% of the threshold, not more than 220% of the threshold, not more than 215% of the threshold, not more than 210% of the threshold, not more than 205% of the threshold, not more than 200% of the threshold, not more than 195% of the threshold, not more than 190% of the threshold, not more than 185% of the threshold, not more than 180% of the threshold, not more than 175% of the threshold, not more than 170% of the threshold, not more than 165% of the threshold, not more than 160% of the threshold, not more than 155% of the threshold, not more than 150% of the threshold, not more than 145% of the threshold, not more than 140% of the threshold, not more than 135% of the threshold, not more than 150% of the threshold the threshold, 130% or less, 125% or less, 120% or less, 115% or less, 110% or less, 100% or less, 95% or less, 90% or less, 85% or less, 80% or less, 75% or less, 70% or less, 65% or less, 60% or less, 55% or less, 50% or less, 45% or less, 40% or less, 35% or less, 30% or less, 25% or less, 20% or less, 15% or less, 10% or less, or 5% or less of the threshold.In one aspect, 8 levels of intervention are applied to the location where the measurement is taken.

[0192] In one aspect, 9 levels of intervention (N=9) are applied to patients who have a Δ value that exceeds the threshold by no more than 500% of the threshold, such as 495% of the threshold, 490% of the threshold, 485% of the threshold, 480% of the threshold, 475% of the threshold, 470% of the threshold, 465% of the threshold, 460% of the threshold, 455% of the threshold, 450% of the threshold, 445% of the threshold, 440% of the threshold, 435% of the threshold, 430% of the threshold, 425% of the threshold, 420% of the threshold, 415% of the threshold, 410% of the threshold, 421% of the threshold, 422% of the threshold, 423% of the threshold, 424% of the threshold, 425% of the threshold, 426% of the threshold, 427% of the threshold, 428% of the threshold, 429% of the threshold, 430% of the threshold, 441% of the threshold, 442% of the threshold, 443% of the threshold, 444% of the threshold, 445% of the threshold, 446% of the threshold, 405% of the threshold, 400% or less, 395% or less, 390% or less, 385% or less, 380% or less, 375% or less, 370% or less, 365% or less, 360% or less, 355% or less, 350% or less, 345% or less, 340% or less, 335% or less, 330% or less, 325% or less, 320% or less, 315% or less, 310% or less, 305% or less, 300% or less, 295% or less %, not more than 290% of the threshold, not more than 285% of the threshold, not more than 280% of the threshold, not more than 275% of the threshold, not more than 270% of the threshold, not more than 265% of the threshold, not more than 260% of the threshold, not more than 255% of the threshold, not more than 250% of the threshold, not more than 245% of the threshold, not more than 240% of the threshold, not more than 235% of the threshold, not more than 230% of the threshold, not more than 225% of the threshold, not more than 220% of the threshold, not more than 215% of the threshold, not more than 210% of the threshold, not more than 205% of the threshold, not more than 200% of the threshold, not more than 195% of the threshold, not more than 190% of the threshold, not more than 185% of the threshold, not more than 180%, not more than 175% of the threshold, not more than 170% of the threshold, not more than 165% of the threshold, not more than 160% of the threshold, not more than 155% of the threshold, not more than 150% of the threshold, not more than 145% of the threshold, not more than 140% of the threshold, not more than 135% of the threshold, not more than 130% of the threshold, not more than 125% of the threshold, not more than 120% of the threshold, not more than 115% of the threshold, not more than 110% of the threshold, not more than 100% of the threshold, not more than 95% of the threshold, not more than 90% of the threshold, not more than 85% of the threshold, not more than 80% of the threshold, not more than 75% of the threshold, not more than 70% of the threshold, not more than 65% of the threshold, not more than 60% of the threshold,No more than 55% of the threshold, no more than 50% of the threshold, no more than 45% of the threshold, no more than 40% of the threshold, no more than 35% of the threshold, no more than 30% of the threshold, no more than 25% of the threshold, no more than 20% of the threshold, no more than 15% of the threshold, no more than 10% of the threshold, or no more than 5% of the threshold. In one aspect, a level 9 intervention is applied to the location where the measurement is taken.

[0193] In one aspect, 10 levels of intervention (N=10) are applied to patients having a delta value that exceeds the threshold by no more than 550% of the threshold, such as no more than 545% of the threshold, no more than 540% of the threshold, no more than 535% of the threshold, no more than 530% of the threshold, no more than 525% of the threshold, no more than 520% ​​of the threshold, no more than 515% of the threshold, no more than 510% of the threshold, no more than 505% of the threshold, no more than 500% of the threshold, no more than 495% of the threshold, no more than 490% of the threshold, no more than 485% of the threshold, no more than 480% of the threshold, no more than 475% of the threshold, no more than 470% of the threshold, no more than 465% of the threshold, no more than 460% of the threshold, no more than 475% of the threshold, no more than 480% of the threshold, no more than 490% of the threshold, no more than 495% of the threshold, no more than 490 ... %, not more than 455% of the threshold, not more than 450% of the threshold, not more than 445% of the threshold, not more than 440% of the threshold, not more than 435% of the threshold, not more than 430% of the threshold, not more than 425% of the threshold, not more than 420% of the threshold, not more than 415% of the threshold, not more than 410% of the threshold, not more than 405% of the threshold, not more than 400% of the threshold, not more than 395% of the threshold, not more than 390% of the threshold, not more than 385% of the threshold, not more than 380% of the threshold, not more than 375% of the threshold, not more than 370% of the threshold, not more than 365% of the threshold, not more than 360% of the threshold, not more than 355% of the threshold, not more than 350% of the threshold, not more than 345%, not more than 340% of the threshold, not more than 335% of the threshold, not more than 330% of the threshold, not more than 325% of the threshold, not more than 320% of the threshold, not more than 315% of the threshold, not more than 310% of the threshold, not more than 305% of the threshold, not more than 300% of the threshold, not more than 295% of the threshold, not more than 290% of the threshold, not more than 285% of the threshold, not more than 280% of the threshold, not more than 275% of the threshold, not more than 270% of the threshold, not more than 265% of the threshold, not more than 260% of the threshold, not more than 255% of the threshold, not more than 250% of the threshold, not more than 245% of the threshold, not more than 240% of the threshold, not more than 235% of the threshold, not more than 230% of the threshold, not more than 225% of the threshold, not more than 220% of the threshold, not more than 215% of the threshold, not more than 210% of the threshold, not more than 205% of the threshold, not more than 200% of the threshold, not more than 195% of the threshold, not more than 190% of the threshold, not more than 185% of the threshold, not more than 180% of the threshold, not more than 175% of the threshold, not more than 170% of the threshold, not more than 165% of the threshold, not more than 160% of the threshold, not more than 155% of the threshold, not more than 150% of the threshold, not more than 145% of the threshold, not more than 140% of the threshold, not more than 135% of the threshold, not more than 130% of the threshold, not more than 125% of the threshold, not more than 120% of the threshold,115% or less of the threshold, 110% or less of the threshold, 100% or less of the threshold, 95% or less of the threshold, 90% or less of the threshold, 85% or less of the threshold, 80% or less of the threshold, 75% or less of the threshold, 70% or less of the threshold, 65% or less of the threshold, 60% or less of the threshold, 55% or less of the threshold, 50% or less of the threshold, 45% or less of the threshold, 40% or less of the threshold, 35% or less of the threshold, 30% or less of the threshold, 25% or less of the threshold, 20% or less of the threshold, 15% or less of the threshold, 10% or less of the threshold, or 5% or less of the threshold. In one aspect, a level 10 intervention is applied to the location where the measurement is taken.

[0194] In one aspect, a Level N intervention is more intensive than a Level 0 intervention. In one aspect, a Level (N+1) intervention is more intensive than a Level N intervention. In one aspect, a Level (N-1) intervention is less intensive than a Level N intervention.

[0195] In one aspect, the evaluating step of the present disclosure further comprises performing a visual assessment. In one aspect, the visual assessment is performed according to the guidelines of the National Pressure Ulcer Advisory Panel (NPUAP).

[0196] In one aspect, the assessing step of the present disclosure further comprises performing a risk assessment. In one aspect, the risk assessment is performed based on a test selected from the group consisting of: Braden scale, Gosnell scale, Norton scale, and Waterlow scale. In one aspect, the assessing step of the present disclosure further comprises performing the assessment using one or more objective measurements selected from the group consisting of: subcutaneous water content, bioimpedance, ultrasound, pressure measurement; capillary pressure, thermal imaging, spectral imaging, transepidermal water loss, and detection of the presence of interleukin-1 alpha at one or more anatomical sites of interest.

[0197] In one aspect, the present disclosure further provides and includes: performing a second plurality of perfusion measurements in the patient at a first predetermined frequency corresponding to a level of intervention applied; calculating a second Δ value based on a portion of the second plurality of perfusion measurements; determining whether the second Δ value exceeds a second threshold, and continuing to implement the first intervention if the second Δ value does not exceed the second threshold; continuing to perform a plurality of perfusion measurements at the first predetermined frequency if the second Δ value does not exceed the second threshold; applying a second intervention of level M if the second Δ value exceeds the second threshold, where M is an integer and M is greater than N; and performing a plurality of perfusion measurements at a second predetermined frequency corresponding to level M if the second Δ value exceeds the second threshold.

[0198] In one aspect, the present disclosure further provides and includes: performing a second plurality of SpO2 measurements in the patient at a first predetermined frequency corresponding to a level of intervention applied; calculating a time delta value based on a difference between the first plurality and the second plurality of SpO2 measurements; determining whether the time delta value is a decrease that exceeds a second threshold; continuing to administer the first intervention if the time delta value does not exceed the second threshold; continuing to perform a plurality of perfusion measurements at the first predetermined frequency if the time delta value does not exceed the second threshold; administering a second intervention of level M if the time delta value is a decrease that exceeds the second threshold, where M is an integer and M is greater than N; and performing a plurality of SpO2 measurements at a second predetermined frequency corresponding to the level M if the time delta value is a decrease that exceeds the second threshold.

[0199] In one aspect, the predetermined frequency is selected from the group consisting of: at least once every 72 hours, at least once every 48 hours, at least once every 24 hours, at least once every 12 hours, at least once every 8 hours, at least once every 6 hours, at least once every 4 hours, at least once every 3 hours, at least once every 2 hours, at least once every hour, at least once every half hour.

[0200] In one aspect, a second plurality of perfusion measurements are made according to

[0175] . In one aspect, the second plurality of perfusion measurements are made at the same locations where the first plurality of perfusion measurements were made. In one aspect, the second plurality of perfusion measurements are made at some of the same locations where the first plurality of perfusion measurements were made. In one aspect, the second plurality of perfusion measurements are made near the locations where the first plurality of perfusion measurements were made. In one aspect, the second plurality of perfusion measurements are made at locations different from the locations where the first plurality of perfusion measurements were made.

[0201] In one aspect, the second delta value is determined by a difference between a maximum perfusion value and a minimum perfusion value from a second plurality of collected perfusion measurements. In one aspect, the second delta value is determined by a difference between a maximum perfusion average of measurements taken at one location and a minimum perfusion average of measurements taken at a second location. In one aspect, the second delta value is determined for a portion of a second plurality of perfusion measurements comprised of a subset defined by the locations at which the measurements were taken.

[0202] In one aspect, the second threshold value can be about 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3. 3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.0, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, 5.0, 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8, 5.9, 6.0, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9, 7.0, 7.1, 7.2, 7.3, 7.4, or 7.5. In one aspect, the second threshold value can be in the range of 0.1 to 8.0, such as 0.1 to 1.0, 1.1 to 2.0, 2.1 to 3.0, 3.1 to 4.0, 4.1 to 5.0, 5.1 to 6.0, 6.1 to 7.0, 7.1 to 8.0, 0.1 to 7.5, 0.5 to 8.0, 1.0 to 7.0, 1.5 to 6.5, 2.0 to 6.0, 3.0 to 5.5, 3.5 to 5.0, or 4.0 to 4.5. In one aspect, the second threshold value for SpO2 measurement can be approximately 3%, 3.5%, 4%, 5%, 5.5%, 6%, 6.6%, or 7%. In one aspect, the second threshold value can be scaled by a factor or multiple based on the values ​​provided herein. In one aspect, the second threshold value can be the same as the first threshold value. In one aspect, the second threshold value can be greater than the first threshold value. In one aspect, the second threshold value can be less than the first threshold value.

[0203] In one aspect, M ranges from 2 to 50, such as 2 to 3, 2 to 4, 2 to 5, 2 to 6, 2 to 7, 2 to 8, 2 to 9, 2 to 10, 2 to 15, 2 to 20, 2 to 25, 2 to 30, 2 to 35, 2 to 40, or 2 to 45.

[0204] In one aspect, M is determined by the amount by which the second delta value exceeds the second threshold. In one aspect, the amount by which the delta value exceeds the threshold established for (M+1) is greater than the amount by which the delta value exceeds the threshold established for M. In one aspect, the amount by which the delta value exceeds the threshold established for (M-1) is less than the amount by which the delta value exceeds the threshold established for M.

[0205] In one aspect, an M-level intervention is selected according to

[0143] to

[0153] , replacing N with M.

[0206] In one aspect, the present disclosure further provides and includes: determining whether the second Δ value is less than a third threshold, applying a (N-1) level intervention if the second Δ value is less than the third threshold and if the first intervention is not level 0; and performing multiple perfusion measurements at a predetermined frequency corresponding to the (N-1) level if the second Δ value is less than the third threshold.

[0207] In one aspect, the present disclosure further provides and includes: determining whether the time Δ value is an increase exceeding a third threshold; if the time Δ value is an increase exceeding the third threshold and if the first intervention is not level 0, applying the (N-1) level intervention; and if the time Δ value is an increase exceeding the third threshold, performing multiple SpO2 measurements at a predetermined frequency corresponding to the (N-1) level.

[0208] In one aspect, the third threshold value can be about 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3. 3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.0, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, 5.0, 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8, 5.9, 6.0, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9, 7.0, 7.1, 7.2, 7.3, 7.4, or 7.5. In one aspect, the third threshold value can be in the range of 0.1 to 8.0, such as 0.1 to 1.0, 1.1 to 2.0, 2.1 to 3.0, 3.1 to 4.0, 4.1 to 5.0, 5.1 to 6.0, 6.1 to 7.0, 7.1 to 8.0, 0.1 to 7.5, 0.5 to 8.0, 1.0 to 7.0, 1.5 to 6.5, 2.0 to 6.0, 3.0 to 5.5, 3.5 to 5.0, or 4.0 to 4.5. In one aspect, the second threshold value for SpO2 measurement can be approximately 3%, 3.5%, 4%, 5%, 5.5%, 6%, 6.6%, or 7%. In one aspect, the third threshold value can be scaled by a factor or multiple based on the values ​​provided herein. In one aspect, the third threshold value can be the same as the second threshold value. In one aspect, the third threshold value can be greater than the second threshold value. In one aspect, the third threshold value can be less than the second threshold value. In one aspect, the third threshold value can be the same as the first threshold value. In one aspect, the third threshold value may be greater than the first threshold value. In one aspect, the third threshold value may be less than the first threshold value.

[0209] In one aspect, the second delta value may be 0.1-99.5% of the third threshold, such as 0.1-1%, 0.1-5%, 1-5%, 5-15%, 10-20%, 15-25%, 20-30%, 25-35%, 30-40%, 35-45%, 40-50%, 0.1-25%, 15-35%, 25-50%, 25-75%, 45-55%, 50-60%, 55-65%, 60-70%, 65-75%, 40-55%, 50-75%, 50-99.5%, 70-80%, 75-85%, 80-90%, 85-95%, 90-99.5%, 65-85%, or 75-99.5% of the third threshold.

[0210] In one aspect, the present disclosure provides and encompasses a method for slowing the progression of skin and tissue damage in a patient in need thereof, the method comprising the steps of: identifying a current intervention level K being received by the patient; taking a plurality of perfusion measurements in the patient; calculating a delta value based on a portion of the plurality of perfusion measurements; determining whether the delta value exceeds a first threshold; if the delta value does not exceed the first threshold, continuing to administer the current intervention; if the delta value does not exceed the first threshold, continuing to administer the plurality of perfusion measurements at a predetermined frequency corresponding to the level K; if the delta value exceeds the first threshold, administering a new intervention level N, where N is greater than K; and if the delta value exceeds the first threshold, administering a plurality of perfusion measurements at a predetermined frequency corresponding to the level N. In one aspect, the patient in need thereof is a patient undergoing a change in care, mobility, nutrition, sensory perception, or a combination thereof. In one aspect, the patient in need thereof is a patient who has developed an open wound. In one aspect, the patient in need thereof is a patient recovering from an open wound. In one aspect, the patient in need thereof is a patient undergoing surgery. In one aspect, the patient in need thereof is a patient recovering from surgery. In one aspect, the patient in need thereof is a patient receiving spinal analgesia or sacral analgesia during surgery. In one aspect, a patient in need thereof is a patient undergoing surgery that lasts four or more hours, such as five or more hours, six or more hours, seven or more hours, eight or more hours, nine or more hours, ten or more hours, eleven or more hours, or twelve or more hours. In one aspect, the surgery lasts one or more hours, such as two or more hours, or three or more hours.

[0211] In one aspect, a plurality of perfusion measurements are performed according to

[0175] . In one aspect, a delta value is determined according to

[0176] . In one aspect, a first threshold is determined according to

[0178] .

[0212] In one aspect, K ranges from 2 to 50, such as 2 to 3, 2 to 4, 2 to 5, 2 to 6, 2 to 7, 2 to 8, 2 to 9, 2 to 10, 2 to 15, 2 to 20, 2 to 25, 2 to 30, 2 to 35, 2 to 40, or 2 to 45.

[0213] In one aspect, K is determined by the amount by which the delta value exceeds a threshold value. In one aspect, the amount by which the delta value exceeds the threshold value established for (K+1) is greater than the amount by which the delta value exceeds the threshold value established for K. In one aspect, the amount by which the delta value exceeds the threshold value established for (K-1) is less than the amount by which the delta value exceeds the threshold value established for K.

[0214] In one aspect, a K-level intervention is selected according to

[0181] to

[0190] , replacing N with K.

[0215] In one aspect, the present disclosure further provides and includes: determining whether the Δ value is less than a second threshold; if the Δ value is less than the second threshold, applying a level L intervention, where L has a non-negative value less than K; and if the Δ value is less than the second threshold, performing multiple perfusion measurements at a predetermined frequency corresponding to the level L.

[0216] In one aspect, the second threshold is determined according to

[0199] .

[0217] In one aspect, the present disclosure provides and includes: determining whether any one of a plurality of SpO2 measurements is above a threshold range corresponding to level K; administering a level L intervention if any one of the plurality of SpO2 measurements is above the threshold range corresponding to level K, where L is a non-negative value less than K; and taking a plurality of perfusion measurements at a predetermined frequency corresponding to level L if any one of the plurality of SpO2 measurements is above the threshold range corresponding to level K. In one aspect, the threshold range is selected from the group consisting of: less than about 85%, about 85% to about 95%, and greater than or equal to 95%.

[0218] In one aspect, L can be K-1, K-2, K-3, K-4, K-5, K-6, K-7, K-8, K-9, or K-10. In one aspect, if the Δ value is 90-99.5% of the second threshold, such as 90-95%, 91-96%, 92-97%, 93-98%, 94-99%, or 95-99.5% of the second threshold, then L is K-1, unless K-1 is less than 0, in which case L will be 0. In one aspect, if the Δ value is 80-89.9% of the second threshold, such as 80-85%, 81-86%, 82-87%, 83-88%, 84-89%, or 85-89.9% of the second threshold, then L is K-2, unless K-2 is less than 0, in which case L will be 0. In one aspect, if the Δ value is 70-79.9% of the second threshold, such as 70-75%, 71-76%, 72-77%, 73-78%, 74-79%, or 75-79.9% of the second threshold, then L is K-3, unless K-3 is less than 0, in which case L will be 0. In one aspect, if the Δ value is 60-69.9% of the second threshold, such as 60-65%, 61-66%, 62-67%, 63-68%, 64-69%, or 65-69.9% of the second threshold, then L is K-4, unless K-4 is less than 0, in which case L will be 0. In one aspect, if the Δ value is 50-59.9% of the second threshold, such as 50-55%, 51-56%, 52-57%, 53-58%, 54-59%, or 55-59.9% of the second threshold, then L is K-5, unless K-5 is less than 0, in which case L will be 0. In one aspect, if the Δ value is 40-49.9% of the second threshold, such as 40-45%, 41-46%, 42-47%, 43-48%, 44-49%, or 45-49.9% of the second threshold, then L is K-6, unless K-6 is less than 0, in which case L will be 0. In one aspect, if the Δ value is 30-39.9% of the second threshold, such as 30-35%, 31-36%, 32-37%, 33-38%, 34-39%, or 35-39.9% of the second threshold, then L is K-7, unless K-7 is less than 0, in which case L will be 0. In one aspect, if the Δ value is 20-29.9% of the second threshold, such as 20-25%, 21-26%, 22-27%, 23-28%, 24-29%, or 25-29.9% of the second threshold, then L is K-8, unless K-8 is less than 0, in which case L will be 0. On the one hand, if the Δ value is 10-19.9% ​​of the second threshold, such as 10-15%, 11-16%, 12-17%, 13-18%, 14-19%, or 15-19.9% ​​of the second threshold, then L is K-9, unless K-9 is less than 0, in which case L will be 0.In one aspect, if the Δ value is 0.1-9.9% of the second threshold, such as 0.1-5%, 1-6%, 2-7%, 3-8%, 4-9%, or 5-9.9% of the second threshold, then L is K-10, unless K-10 is less than 0, in which case L will be 0.

[0219] In one aspect, the present disclosure provides and includes a method for stratifying patient groups in a care facility based on risk of tissue damage, the method comprising the steps of: performing multiple perfusion measurements in each patient; calculating a Δ value based on a portion of the multiple perfusion measurements for each patient; determining whether each Δ value exceeds any value in a set of thresholds corresponding to N levels of care and assigning a level of care to each patient; and rearranging the patient groups based on the level of care assigned to each patient.

[0220] In one aspect, the present disclosure provides and includes a method for stratifying patient groups in a care facility based on risk of wound development, the method comprising the steps of: taking multiple SpO2 measurements in each patient; determining whether each of the multiple SpO2 measurements is below any value in a set of thresholds corresponding to N levels of care and assigning a level of care to each patient; and re-arranging patient groups based on the level of care assigned to each patient.

[0221] In one aspect, the present disclosure provides and includes a method for reducing the incidence of tissue damage in a patient admitted to a nursing facility, the method comprising the steps of: assessing the risk of tissue damage in the patient upon admission to the nursing facility, wherein the assessing step comprises: performing a first plurality of perfusion measurements in the patient; calculating a first Δ value based on a portion of the first plurality of perfusion measurements; determining whether the first Δ value exceeds a first threshold; if the first Δ value does not exceed the first threshold, applying a level 0 first intervention; and if the first Δ value exceeds the first threshold, applying a level N first intervention, wherein N is an integer and the value of N is 1 or greater. In one aspect, the present disclosure provides and encompasses a method for reducing the incidence of wound development in a patient admitted to a nursing facility, the method comprising the steps of: assessing the patient's risk of tissue damage upon admission to the nursing facility, wherein the assessing step comprises: performing a first plurality of SpO2 measurements on the patient; calculating a first delta value based on a portion of the first plurality of SpO2 measurements; determining whether any of the first plurality of SpO2 measurements is below a first threshold; administering a level 0 first intervention if the first plurality of SpO2 measurements is above or equal to the first threshold; and administering a level N intervention if the first plurality of SpO2 measurements is below the first threshold, wherein N is an integer and the value of N is 1 or greater. In one aspect, the incidence of ulcers in the patient admitted to the nursing facility is reduced to less than 1 / 100, less than 1 / 200, less than 1 / 300, less than 1 / 400, less than 1 / 500, less than 1 / 600, less than 1 / 700, less than 1 / 800, less than 1 / 900, or less than 1 / 1000.

[0222] In one aspect, the present disclosure provides and encompasses a method for identifying and treating a patient who needs to have a skin cream applied to their heel, the method comprising the steps of: taking a plurality of perfusion measurements at the patient's heel; calculating a delta value based on a portion of the plurality of perfusion measurements; determining whether the delta value exceeds a threshold corresponding to level N, where N is greater than or equal to 2; applying a skin cream to the patient's heel if the delta value exceeds the threshold; and taking a plurality of perfusion measurements every two hours if the delta value exceeds the threshold. In one aspect, taking a plurality of perfusion measurements at least once an hour or at least once every half hour if the delta value exceeds the threshold.

[0223] In one aspect, the present disclosure provides and includes a method for identifying and treating a patient who needs to have a lotion applied to their heels, the method comprising the steps of: taking a plurality of SpO2 measurements at the patient's heel; determining whether any of the plurality of SpO2 measurements is below a threshold corresponding to level N, where N is greater than or equal to 2; applying a lotion to the patient's heel if any of the plurality of SpO2 values ​​is below the threshold; and taking a plurality of SpO2 measurements every two hours if any of the plurality of SpO2 measurements is below the threshold.

[0224] In one aspect, the present disclosure provides and encompasses a method for identifying and treating a patient requiring neuromuscular stimulation of their heel, the method comprising the steps of: taking a plurality of perfusion measurements at the patient's heel; calculating a delta value based on a portion of the plurality of perfusion measurements; determining whether the delta value exceeds a threshold corresponding to a level N, where N is greater than or equal to 2; administering neuromuscular stimulation to the patient's heel if the delta value exceeds the threshold; and taking a plurality of perfusion measurements every hour if the delta value exceeds the threshold. In one aspect, the plurality of perfusion measurements is taken at least once every half hour if the delta value exceeds the threshold.

[0225] In one aspect, the present disclosure provides and includes a method of identifying and treating a patient in need of neuromuscular stimulation applied to their heel, the method comprising the steps of: taking a plurality of SpO2 measurements at the patient's heel; determining whether any of the plurality of SpO2 measurements is below a threshold corresponding to level N, where N is greater than or equal to 2; applying neuromuscular stimulation to the patient's heel if any of the plurality of SpO2 measurements is below the threshold; and taking a plurality of SpO2 measurements every hour if any of the plurality of SpO2 measurements is below the threshold.

[0226] In one aspect, the present disclosure provides and includes a method of identifying and treating a patient who needs application of a topical cream to their heel, the method comprising the steps of: taking a plurality of perfusion measurements at the patient's heel; calculating a delta value based on a portion of the plurality of perfusion measurements; determining whether the delta value exceeds a threshold corresponding to a level N, where N is greater than or equal to 2; applying a topical cream to the patient's heel if the delta value exceeds the threshold; and taking a plurality of perfusion measurements every half hour if the delta value exceeds the threshold.

[0227] In one aspect, the present disclosure provides and includes a method of identifying and treating a patient who needs application of a topical cream to their heel, the method comprising the steps of: taking a plurality of SpO2 measurements at the patient's heel; determining whether any of the plurality of SpO2 measurements is below a threshold corresponding to level N, where N is greater than or equal to 2; applying a topical cream to the patient's heel if any of the plurality of SpO2 measurements is below the threshold; and taking a plurality of SpO2 measurements every half hour if any of the plurality of SpO2 measurements is below the threshold.

[0228] In one aspect, the present disclosure provides and includes a method for identifying and treating a patient who requires a heel boot to be applied to their heel, the method comprising the steps of: taking a plurality of perfusion measurements at the patient's heel; calculating a delta value based on a portion of the plurality of perfusion measurements; determining whether the delta value exceeds a threshold corresponding to level N, where N is greater than or equal to 2; applying a heel boot to the patient's heel if the delta value exceeds the threshold; and taking a plurality of perfusion measurements every half hour if the delta value exceeds the threshold.

[0229] In one aspect, the present disclosure provides and includes a method of identifying and treating a patient requiring application of a heel boot to their heel, the method comprising the steps of: taking a plurality of SpO2 measurements at the patient's heel; determining whether any of the plurality of SpO2 measurements is below a threshold corresponding to level N, where N is greater than or equal to 2; applying the heel boot to the patient's heel if any of the plurality of SpO2 measurements is below the threshold; and taking a plurality of SpO2 measurements every half hour if any of the plurality of SpO2 measurements is below the threshold.

[0230] In one aspect, the present disclosure provides and encompasses a method for identifying and treating a patient who needs to have a skin cream applied to their sacrum, the method comprising the steps of: taking a plurality of perfusion measurements at the patient's sacrum; calculating a delta value based on a portion of the plurality of perfusion measurements; determining whether the delta value exceeds a threshold corresponding to level N, where N is greater than or equal to 2; applying a skin cream to the patient's sacrum if the delta value exceeds the threshold; and taking a plurality of perfusion measurements every six hours if the delta value exceeds the threshold. In one aspect, if the delta value exceeds the threshold, taking a plurality of perfusion measurements at least once every four hours, at least once every three hours, at least once every two hours, at least once every hour, or at least once every half hour.

[0231] In one aspect, the present disclosure provides and includes a method for identifying and treating a patient who needs to have a lotion applied to their sacrum, the method comprising the steps of: taking a plurality of SpO2 measurements at the patient's sacrum; determining whether any of the plurality of SpO2 measurements is below a threshold corresponding to level N, where N is greater than or equal to 2; applying a lotion to the patient's sacrum if any of the plurality of SpO2 measurements is below the threshold; and taking a plurality of SpO2 measurements every six hours if any of the plurality of SpO2 measurements is below the threshold.

[0232] In one aspect, the present disclosure provides and encompasses a method for identifying and treating a patient in need of neuromuscular stimulation of their sacrum, the method comprising the steps of: taking a plurality of perfusion measurements at the patient's sacrum; calculating a delta value based on a portion of the plurality of perfusion measurements; determining whether the delta value exceeds a threshold corresponding to a level N, where N is greater than or equal to 2; administering neuromuscular stimulation to the patient's sacrum if the delta value exceeds the threshold; and taking the plurality of perfusion measurements every four hours if the delta value exceeds the threshold. In one aspect, if the delta value exceeds the threshold, taking the plurality of perfusion measurements at least once every three hours, at least once every two hours, at least once every hour, or at least once every half hour.

[0233] In one aspect, the present disclosure provides and includes a method of identifying and treating a patient in need of neuromuscular stimulation applied to their sacrum, the method comprising the steps of: taking a plurality of SpO2 measurements at the patient's sacrum; determining whether any of the plurality of SpO2 measurements is below a threshold corresponding to level N, where N is greater than or equal to 2; administering neuromuscular stimulation to the patient's sacrum if any of the plurality of SpO2 measurements is below the threshold; and taking a plurality of SpO2 measurements every four hours if any of the plurality of SpO2 measurements is below the threshold.

[0234] In one aspect, the present disclosure provides and encompasses a method for identifying and treating a patient who requires application of a topical cream to their sacrum, the method comprising the steps of: taking a plurality of perfusion measurements at the patient's sacrum; calculating a delta value based on a portion of the plurality of perfusion measurements; determining whether the delta value exceeds a threshold corresponding to a level N, where N is greater than or equal to 2; applying a topical cream to the patient's sacrum if the delta value exceeds the threshold; and taking a plurality of perfusion measurements every two hours if the delta value exceeds the threshold. In one aspect, taking a plurality of perfusion measurements at least once an hour or at least once every half hour if the delta value exceeds the threshold.

[0235] In one aspect, the present disclosure provides and encompasses a method of identifying and treating a patient in need of application of a topical cream to their sacrum, the method comprising the steps of: taking a plurality of SpO2 measurements at the patient's sacrum; determining whether any of the plurality of SpO2 measurements is below a threshold corresponding to level N, where N is greater than or equal to 2; applying a topical cream to the patient's sacrum if any of the plurality of SpO2 measurements is below the threshold; and taking a plurality of SpO2 measurements every two hours if any of the plurality of SpO2 measurements is below the threshold.

[0236] In one aspect, the present disclosure provides and encompasses a method for identifying and treating a patient in need of therapeutic ultrasound, the method comprising the steps of: taking a plurality of perfusion measurements at an anatomical site of the patient; calculating a delta value based on a portion of the plurality of perfusion measurements; determining whether the delta value exceeds a threshold corresponding to level N, where N is greater than or equal to 2; administering therapeutic ultrasound to the anatomical site if the delta value exceeds the threshold; and taking a plurality of perfusion measurements every two hours if the delta value exceeds the threshold. In one aspect, the anatomical site is selected from the group consisting of: the patient's sternum, sacrum, heel, scapula, elbow, ear, and other bony prominences of the patient.

[0237] In one aspect, the present disclosure provides and encompasses a method for identifying and treating a patient in need of therapeutic ultrasound, the method comprising the steps of: taking a plurality of SpO2 measurements at an anatomical site of the patient; determining whether any of the plurality of SpO2 measurements is below a threshold corresponding to level N, where N is greater than or equal to 2; and administering therapeutic ultrasound to the anatomical site if any of the plurality of SpO2 measurements is below the threshold. In one aspect, the anatomical site is selected from the group consisting of: the patient's sternum, sacrum, heel, scapula, elbow, ear, and other bony prominences of the patient.

[0238] In one aspect, the present disclosure provides and encompasses a method of identifying and treating a patient in need of shock wave therapy, the method comprising the steps of: taking a plurality of perfusion measurements at an anatomical site of the patient; calculating a delta value based on a portion of the plurality of perfusion measurements; determining whether the delta value exceeds a threshold corresponding to level N, where N is greater than or equal to 2; administering shock wave therapy to the anatomical site if the delta value exceeds the threshold; and taking a plurality of perfusion measurements every two hours if the delta value exceeds the threshold. In one aspect, the anatomical site is selected from the group consisting of: the patient's sternum, sacrum, heel, scapula, elbow, ear, and other bony prominences of the patient's flesh. In one aspect, the shock wave therapy is provided by electromagnetic pulses or pressurized air.

[0239] In one aspect, the present disclosure provides and encompasses a method for identifying and treating a patient in need of shock wave therapy, the method comprising the steps of: taking a plurality of SpO2 measurements at an anatomical site of the patient; determining whether any of the plurality of SpO2 measurements is below a threshold corresponding to level N, where N is greater than or equal to 2; and administering shock wave therapy to the anatomical site if any of the plurality of SpO2 measurements is below the threshold. In one aspect, the anatomical site is selected from the group consisting of: the patient's sternum, sacrum, heel, scapula, elbow, ear, and other bony prominences of the flesh. In one aspect, the shock wave therapy is provided via electromagnetic pulses or pressurized air.

[0240] In one aspect, the present disclosure provides and encompasses a method for identifying and treating a patient requiring application of a 30-degree wedge, the method comprising the steps of: taking a plurality of perfusion measurements at an anatomical site of the patient; calculating a delta value based on a portion of the plurality of perfusion measurements; determining whether the delta value exceeds a threshold corresponding to level N, where N is greater than or equal to 2; applying a 30-degree wedge to the anatomical site if the delta value exceeds the threshold; and taking a plurality of perfusion measurements every two hours if the delta value exceeds the threshold. In one aspect, the anatomical site is selected from the group consisting of: flesh tissue over the patient's sternum, sacrum, heel, scapula, elbow, ear, and other bony prominences.

[0241] In one aspect, the present disclosure provides and encompasses a method of identifying and treating a patient requiring application of a 30-degree wedge, the method comprising the steps of: taking a plurality of SpO2 measurements at an anatomical site of the patient; determining whether any of the plurality of SpO2 measurements is below a threshold corresponding to level N, where N is greater than or equal to 2; and applying a 30-degree wedge to the anatomical site if any of the plurality of SpO2 measurements is below the threshold. In one aspect, the anatomical site is selected from the group consisting of: flesh tissue over the patient's sternum, sacrum, heel, scapula, elbow, ear, and other bony prominences.

[0242] In one aspect, the present disclosure provides and encompasses a method for identifying and treating a patient requiring a composite dressing, the method comprising the steps of: taking a plurality of perfusion measurements at an anatomical site of the patient; calculating a delta value based on a portion of the plurality of perfusion measurements; determining whether the delta value exceeds a threshold corresponding to level N, where N is greater than or equal to 2; applying a composite dressing to the anatomical site if the delta value exceeds the threshold; and taking a plurality of perfusion measurements every two hours if the delta value exceeds the threshold. In one aspect, the anatomical site is selected from the group consisting of: the patient's sternum, sacrum, heel, scapula, elbow, ear, and other bony prominences of the patient.

[0243] In one aspect, the present disclosure provides and encompasses a method of identifying and treating a patient requiring application of a composite dressing, the method comprising the steps of: taking a plurality of SpO2 measurements at an anatomical site of the patient; determining whether any of the plurality of SpO2 measurements is below a threshold corresponding to level N, where N is greater than or equal to 2; and applying a composite dressing to the anatomical site if any of the plurality of SpO2 measurements is below the threshold. In one aspect, the anatomical site is selected from the group consisting of: flesh tissue over the patient's sternum, sacrum, heel, scapula, elbow, ear, and other bony prominences.

[0244] In one aspect, the present disclosure provides and encompasses a method for identifying and treating a patient in need of a hybrid mattress, the method comprising the steps of: taking a plurality of perfusion measurements at an anatomical site of the patient; calculating a delta value based on a portion of the plurality of perfusion measurements; determining whether the delta value exceeds a threshold corresponding to a level N, where N is greater than or equal to 2; providing a hybrid mattress to support the patient if the delta value exceeds the threshold; and taking a plurality of perfusion measurements every two hours if the delta value exceeds the threshold. In one aspect, the anatomical site is selected from the group consisting of: the patient's sternum, sacrum, heel, scapula, elbow, ear, and other bony prominences of the patient.

[0245] In one aspect, the present disclosure provides and encompasses a method for identifying and treating a patient requiring application of a hybrid mattress, the method comprising the steps of: taking a plurality of SpO2 measurements at an anatomical site of the patient; determining whether any of the plurality of SpO2 measurements is below a threshold corresponding to level N, where N is greater than or equal to 2; and providing a hybrid mattress to support the patient if any of the plurality of SpO2 measurements is below the threshold. In one aspect, the anatomical site is selected from the group consisting of: the patient's sternum, sacrum, heel, scapula, elbow, ear, and other bony prominences of the patient.

[0246] In one aspect, the present disclosure provides and encompasses a method for identifying and treating a patient in need of a powered mattress, the method comprising the steps of: taking a plurality of perfusion measurements at an anatomical site of the patient; calculating a delta value based on a portion of the plurality of perfusion measurements; determining whether the delta value exceeds a threshold corresponding to a level N, where N is greater than or equal to 2; providing a powered mattress to support the patient if the delta value exceeds the threshold; and taking a plurality of perfusion measurements every two hours if the delta value exceeds the threshold. In one aspect, the anatomical site is selected from the group consisting of: the patient's sternum, sacrum, heel, scapula, elbow, ear, and other bony prominences of the patient.

[0247] In one aspect, the present disclosure provides and encompasses a method for identifying and treating a patient requiring application of a powered mattress, the method comprising the steps of: taking a plurality of SpO2 measurements at an anatomical site of the patient; determining whether any of the plurality of SpO2 measurements is below a threshold corresponding to level N, where N is greater than or equal to 2; and providing a powered mattress to support the patient if any of the plurality of SpO2 measurements is below the threshold. In one aspect, the anatomical site is selected from the group consisting of: flesh over the patient's sternum, sacrum, heel, scapula, elbow, ear, and other bony prominences.

[0248] In one aspect, the present disclosure provides and includes a method for identifying and moving a long-term bedridden patient in need, the method comprising the steps of: providing a motion sensor including an accelerometer and a gyroscope sensor; monitoring the frequency and range of the patient's activity; issuing an alarm when the motion sensor does not sense more than a quarter turn of movement within a specified time period; and moving the patient upon the alarm.

[0249] In one aspect, the present disclosure further provides and includes providing targeted therapy to an anatomical location of a patient identified as compromised by a combination of visual assessment and perfusion measurements. In one aspect, targeted therapy is provided to a general site of wound development selected from the group consisting of: toes, heels, sacrum, spine, elbows, scapulas, occipital bone, and ischial tuberosity. In one aspect, targeted therapy is simultaneously provided to a second general site of wound development selected from the group consisting of: toes, heels, sacrum, spine, elbows, scapulas, occipital bone, and ischial tuberosity. In one aspect, a first site receiving targeted therapy is known to cause wound development at the second site.

[0250] Compare bilaterally symmetrical perfusion measurements to identify damaged tissue

[0251] Figure 22A The sacral region of the back of patient 1910 is depicted. A line of symmetry 1912 can be drawn down the center of the back, dividing the back into left and right mirror images. Position 1914 is approximately the same distance from line of symmetry 1912 and at approximately the same height, and is therefore considered a bilaterally symmetrical position on the back of patient 1910.

[0252] Figure 22B The left foot 20L and the right foot 20R of the patient 10 are depicted as if the patient 10 were lying on a bed (not shown) with an observer standing at the foot of the bed. Positions 24L and 24R are located at approximately equal positions relative to the soles 22L and 22R of the feet 20L and 20R, e.g., at the same distance from the back (i.e., the heel) and the same distance from the medial side of the respective foot 20L or 20R, and are considered to be bilaterally symmetrical positions.

[0253] Figure 22CAdditional exemplary bilaterally symmetrical locations 26L and 26R are shown located on the sides of feet 20L and 20R, and bilaterally symmetrical locations 28L and 28R are located on the soles 22L and 22R of feet 20L and 20R, respectively. In one aspect, locations 26R and 30R are considered bilaterally symmetrical relative to foot 20R when considered alone without reference to foot 20L.

[0254] Without being bound by a particular theory, comparing perfusion measurements taken at bilaterally symmetrical locations can compensate for deviations in readings from a specific patient and from the patient population. For example, a patient may be dehydrated on a particular day when the measurement is taken. Comparing perfusion values ​​from healthy tissue from the same patient while dehydrated may deviate from perfusion values ​​for the same tissue at the same location when the patient is well hydrated. If tissue at one location is healthy and tissue at a bilaterally symmetrical location is damaged, comparing readings taken at the bilaterally symmetrical locations will eliminate the "common mode" effects of dehydration variations at both locations and provide a more reliable indication of damaged tissue at one location.

[0255] like Figure 4 The perfusion measurement device 400 provided in the present disclosure can be used to take measurements at multiple locations, such as a first measurement at a first location and a second measurement at a second location that is bilaterally symmetrical with respect to the first location. In one aspect, the device 400 includes a processor that can be configured by instructions stored on a non-transitory computer-readable medium to determine characteristics of the measurements taken at the multiple locations or parameters associated with or derived from the measurements, such as one or more of the following: a difference between perfusion values ​​derived from the multiple measurements, an average, or a common average. In one aspect, the device 400 includes a display configured to display one or more parameters associated with the measurements, such as a delta between perfusion values ​​derived from measurements taken at two bilaterally symmetrical locations.

[0256] In one aspect, device 400 performs measurements using two receivers 430A and 430B substantially simultaneously. In one aspect, device 400 performs measurements sequentially, with the time interval between measurements ranging from zero to one second or longer. In one aspect, measurements by device 400 are triggered by actuating a button or actuator. In one aspect, measurements by device 400 are automatically triggered based on input from a switch element as part of device 400, such as, in one aspect, a contact sensor, pressure sensor, optical sensor, or other type of proximity detection device positioned proximate to one or more of receivers 430A and 430B. In one aspect, multiple switch elements must be activated simultaneously to provide input to perform a measurement. In one aspect, device 400 includes a processor coupled to circuitry and receiving information from the circuitry regarding the measured reflected light. In one aspect, the information is in the form of an analog signal, such as a voltage or a digital signal. In one aspect, the processor is directly coupled to the multiple receivers and configured to directly measure the reflected light. In one aspect, the processor is configured to convert the multiple received reflected light measurements into a plurality of perfusion values. In one aspect, the processor is configured by machine-readable instructions stored on a non-transitory computer-readable medium electronically coupled to the processor. In one aspect, the instructions are loaded from the medium to the processor when the device 400 is powered on.

[0257] In one aspect, the measured parameter of reflected light is related to the perfusion of blood in the epidermis at a depth determined by the spatial geometry of receivers 430A and 430B, the wavelength or wavelengths of light emitted by emitter 420, and other operating characteristics of device 400. In one aspect, the magnitude of reflected light detected by receiver 430 is equal to the perfusion at a predetermined scale value. In one aspect, the predetermined scale can be in the range of 0 to 20, such as 0 to 1, 0 to 2, 0 to 3, 0 to 4, 0 to 5, 0 to 6, 0 to 7, 0 to 8, 0 to 9, 0 to 10, 0 to 11, 0 to 12, 0 to 13, 0 to 14, 0 to 15, 0 to 16, 0 to 17, 0 to 18, 0 to 19. In one aspect, the predetermined scale can be scaled by a factor or multiple based on the values ​​provided herein. In one aspect, multiple measurements are taken while varying one or more operating characteristics between readings, thereby providing information related to perfusion at various depths of the skin.

[0258] In one aspect, a difference between the perfusion values ​​is determined, wherein a difference exceeding a predetermined threshold indicates tissue damage at one of the locations where the corresponding perfusion measurement was taken. In one aspect, a mean of the perfusion values ​​obtained at each bilaterally symmetrical location is determined and compared. In one aspect, a median or mode of the perfusion values ​​obtained at each bilaterally symmetrical location is determined and compared. In one aspect, the location associated with the larger of the perfusion values ​​is indicated. In one aspect, the location associated with the smaller of the perfusion values ​​is indicated. In one aspect, determining whether tissue damage is present comprises one or more of: comparing each of the perfusion values ​​to one or more predetermined ranges or thresholds, and comparing the difference to one or more predetermined ranges or thresholds. In one aspect, the predetermined range can be 0.1 to 8.0, such as 0.1 to 1.0, 1.1 to 2.0, 2.1 to 3.0, 3.1 to 4.0, 4.1 to 5.0, 5.1 to 6.0, 6.1 to 7.0, 7.1 to 8.0, 0.1 to 7.5, 0.5 to 8.0, 1.0 to 7.0, 1.5 to 6.5, 2.0 to 6.0, 3.0 to 5.5, 3.5 to 5.0, or 4.0 to 4.5. In one aspect, the predetermined range can be 0.1 to 4.0, such as 0.5 to 4.0, 0.1 to 3.5, 1.0 to 3.5, 1.5 to 4.0, 1.5 to 3.5, 2.0 to 4.0, 2.5 to 3.5, 2.0 to 3.0, 2.0 to 2.5, or 2.5 to 3.0. In one aspect, the predetermined range can be 4.1 to 8.0, such as 4.5 to 8.0, 4.1 to 7.5, 5.0 to 7.5, 5.5 to 7.0, 5.5 to 7.5, 6.0 to 8.0, 6.5 to 7.5, 6.0 to 7.0, 6.0 to 6.5, or 6.5 to 7.0. In one aspect, the predetermined threshold value can be about 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3. 3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.0, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, 5.0, 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8, 5.9, 6.0, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9, 7.0, 7.1, 7.2, 7.3, 7.4, or 7.5.In one aspect, the predetermined threshold value can be in the range of 0.1 to 8.0, such as 0.1 to 1.0, 1.1 to 2.0, 2.1 to 3.0, 3.1 to 4.0, 4.1 to 5.0, 5.1 to 6.0, 6.1 to 7.0, 7.1 to 8.0, 0.1 to 7.5, 0.5 to 8.0, 1.0 to 7.0, 1.5 to 6.5, 2.0 to 6.0, 3.0 to 5.5, 3.5 to 5.0, or 4.0 to 4.5. In one aspect, the predetermined range or threshold value can be scaled by a factor or multiple based on the values ​​provided herein. It should be understood that the predetermined value is not limited by design, but rather, one of ordinary skill in the art will be able to select a predetermined value based on a given perfusion unit. In one aspect, the ranges and threshold values ​​disclosed herein vary depending on the specific bilaterally symmetrical location, the part of the patient's body at which the measurement is made, or one or more characteristics of the patient (such as age, height, weight, family history, race, and other physical characteristics or medical conditions).

[0259] One or more regions can be defined on the body. In one aspect, measurements taken within a region are considered equivalent to one another. A region can be defined as a site on the skin of the body where measurements can be taken at any point within the site. In one aspect, a region corresponds to an anatomical region (e.g., a heel, ankle, lower back). In one aspect, a region can be defined as a set of two or more specific points relative to an anatomical feature where measurements are taken only at the specific points. In one aspect, a region can include multiple discrete sites on the body. In one aspect, a set of specific locations can include points in multiple discrete sites.

[0260] In one aspect, the region is defined by surface area. In one aspect, the region can be, for example, between 5 and 200 cm 2 Between 5 and 100 cm 2 Between 5 and 50 cm 2 Between 10 and 50 cm 2 Between 10 and 25 cm 2 Between or 5 to 25cm 2 between.

[0261] In one aspect, measurements can be taken in a specific pattern or a portion thereof. In one aspect, a pattern with a target region of interest centered is used as a reading pattern. In one aspect, measurements can be taken in one or more circular patterns of increasing or decreasing size, a T-shaped pattern, a set of specific locations, or randomly across a tissue or region. In one aspect, a pattern can be positioned on a body by defining a first measurement location of the pattern relative to an anatomical feature, wherein the remaining measurement locations of the pattern are defined as offsets from the first measurement location.

[0262] In one aspect, multiple measurements are taken on a tissue or region, and the difference between the lowest and highest measurements of the multiple measurements is recorded as the delta value of the multiple measurements. In one aspect, 3 or more, 4 or more, 5 or more, 6 or more, 7 or more, 8 or more, 9 or more, or 10 or more measurements are taken on a tissue or region.

[0263] In one aspect, a threshold value can be established for at least one region. In one aspect, a threshold value of 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, or another value can be established for at least one region. In one aspect, a delta value is identified as significant when delta values ​​for a plurality of measurements taken within a region meet or exceed a threshold value associated with that region. In one aspect, each of the plurality of regions has a different threshold value. In one aspect, two or more regions can have a common threshold value.

[0264] In one aspect, the threshold has both a delta value component and a temporal component, wherein the delta value is identified as significant when it is greater than a predetermined value within a predetermined portion of the time interval. In one aspect, the predetermined portion of the time interval is defined as a minimum of X days where multiple measurements taken on that day produce a delta value greater than or equal to the predetermined value for a total of Y consecutive measurement days. In one aspect, the predetermined portion of the time interval can be defined as 1, 2, 3, 4, or 5 consecutive days where multiple measurements taken on that day produce a delta value greater than or equal to the predetermined value. In one aspect, the predetermined portion of the time interval can be defined as a portion of different specific time periods (weeks, months, hours, etc.).

[0265] In one aspect, the threshold has a trending aspect, wherein changes in delta values ​​across a plurality of consecutive measurements are compared to one another. In one aspect, a trending threshold is defined as a predetermined change in delta values ​​over a predetermined time period, whereby a determination that the threshold has been reached or exceeded is significant. In one aspect, a determination of significance results in the issuance of an alarm. In one aspect, a trend line can be calculated based on a portion of each of the plurality of consecutive measurements. In one aspect, a trend line can be calculated based on a portion of the delta values ​​across the plurality of consecutive measurements.

[0266] In one aspect, the number of measurements taken within a single region can be less than the number of measurement locations defined in the pattern. In one aspect, a delta value is calculated after a predetermined initial number of readings has been taken in the region, which is less than the number of measurement locations defined in the pattern, and after each additional reading in the same region, wherein no additional readings are taken once the delta value reaches or exceeds a threshold associated with the region.

[0267] In one aspect, the number of measurements taken in a single region may exceed the number of measurement locations defined in the pattern.In one aspect, a delta value will be calculated after each additional reading.

[0268] In one aspect, a quality metric can be generated for each of the multiple measurements. In one aspect, this quality metric is selected to evaluate the repeatability of the measurements. In one aspect, this quality metric is selected to evaluate the skill of the clinician performing the measurements. In one aspect, the quality metric can include one or more statistical parameters, such as an average, mean, or standard deviation. In one aspect, the quality metric can include one or more of comparing each measurement to a predetermined range. In one aspect, the quality metric can include comparing each measurement to a pattern of values, such as comparing a measurement at a predetermined location to a range associated with each predetermined location. In one aspect, the quality metric can include determining which measurements were made on healthy tissue, and one or more assessments of consistency within this subset of "healthy" measurements, such as range, standard deviation, or other parameters.

[0269] In one aspect, the device 400 is capable of storing a plurality of measurements and calculations. In one aspect, a device according to the present disclosure may also include other components, such as a barcode scanner, and may store the output of such components. In one aspect, the device 400 includes components for transmitting the stored data to another device, such as a personal computer, server, tablet, or smartphone, such as a Bluetooth, WiFi, or Ethernet connection. Figure 13 shown.

[0270] In one aspect, device 400 includes two receivers 430A and 430B located at separate locations on the device body. An example usage is to place device 400 against a patient's body to position first receiver 430A at a first body location and simultaneously position second receiver 430B at a second body location, where both body locations are on the surface of the patient's skin. In one aspect, the device body is rigid and holds receivers 430A and 430B at a fixed separation distance and in a fixed orientation from one another. In one aspect, receivers 430A and 430B are aligned on a common plane.

[0271] In one aspect, the device body of device 400 is flexible, such that receivers 430A and 430B can be oriented at an angle relative to each other. In one aspect, one or more of receivers 430 are movable, such that the angle between a movable receiver and another receiver can be changed, for example, to match the orientation of the skin. In one aspect, both receivers are movable. In one aspect, all receivers are movable. In one aspect, device 400 includes a hinge, such that the separation distance between receivers 430A and 430B can be changed. In one aspect, the device body of device 400 is rigid, such that the angle and separation distance between the receivers are unchangeable.

[0272] In one aspect, device 400 includes a plurality of transmitters 420 and a plurality of receivers 430 forming a planar array. In one aspect, the planar array can take the form of a mat on which the transmitters 420 and receivers 430 are disposed. In one aspect, the transmitters 420 and receivers 430 are embedded within the mat. In one aspect, the transmitters 420 and receivers 430 are located on the top surface of the mat. In one aspect, the transmitters 420 and receivers 430 have a covering layer thereon. In one aspect, the transmitters 420 are of a single type and configuration within the array. In one aspect, the receivers 430 are of a single type and configuration within the array. In one aspect, the transmitters 420 and receivers 430 vary in size and type within the array. In one aspect, the receivers 430 vary in size and type within the array. In one aspect, the transmitters 420 and receivers 430 of the array are arranged in a regular geometric pattern, such as a grid-like pattern. In one aspect, the transmitters 420 and receivers 430 of the array are arranged in an irregular pattern. In one aspect, the mat is coupled to electronic components directly or via a cable. In one aspect, the electronic assembly includes circuitry coupled to a receiver 430 and a processor coupled to the circuitry. In one aspect, the mat includes one or more of a pressure sensor, a temperature sensor, an optical sensor, and a contact sensor disposed at one or more corresponding locations on the mat. In one aspect, one or more measurements using receiver 430 are triggered by input from one or more of the pressure, temperature, optical, and contact sensors. In one aspect, the mat is configured as a floor mat, and actuation of one or more of the pressure, temperature, optical, and contact sensors (e.g., due to detection of a person standing on the mat by a pressure sensor due to the person's weight) initiates a measurement by one or more receivers 430. In one aspect, receiver 430 operates in a "detection mode" capable of detecting when a person steps on the mat, and transitions to a "measurement mode" upon determining that a person is standing on the mat. In one aspect, the mat is configured as a portable device that can be placed against a surface of a patient's skin while the patient is lying in bed, such as against the patient's back or against the soles of one or both of the patient's feet. In one aspect, the mat includes one or more of a support tray, a reinforcement element, and a conformal pad to assist in positioning receiver 430 against the patient's skin surface.

[0273] In one aspect, the two emitters may overlap by 0-50%, such as 0-10%, 5-15%, 10-20%, 15-25%, 20-30%, 25-35%, 30-40%, 35%-45%, 40-50%, 0-25%, 15-35%, or 25-50%. In one aspect, the two emitters may overlap by 25-75%, such as 25-35%, 30-40%, 35%-45%, 40-50%, 45-55%, 50-60%, 55-65%, 60-70%, 65-75%, 25-50%, 40-55%, or 50-75%. In one aspect, two emitters may overlap by 50-100%, such as 50-60%, 55-65%, 60-70%, 65-75%, 70-80%, 75%-85%, 80-90%, 85-95%, 90-100%, 50-75%, 65-85%, or 75-100%.

[0274] In one aspect, the two receivers can overlap by 0-50%, such as 0-10%, 5-15%, 10-20%, 15-25%, 20-30%, 25-35%, 30-40%, 35%-45%, 40-50%, 0-25%, 15-35%, or 25-50%. In one aspect, the two receivers can overlap by 25-75%, such as 25-35%, 30-40%, 35%-45%, 40-50%, 45-55%, 50-60%, 55-65%, 60-70%, 65-75%, 25-50%, 40-55%, or 50-75%. In one aspect, the two receivers may overlap by 50-100%, such as 50-60%, 55-65%, 60-70%, 65-75%, 70-80%, 75%-85%, 80-90%, 85-95%, 90-100%, 50-75%, 65-85%, or 75-100%.

[0275] In one aspect, the planar array can further include a plurality of contact sensors on the same planar surface as and surrounding each receiver to ensure that each transmitter and receiver is in full contact with the skin surface. The plurality of contact sensors can be a plurality of pressure sensors, a plurality of light sensors, a plurality of temperature sensors, a plurality of pH sensors, a plurality of sweat sensors, a plurality of ultrasound sensors, a plurality of bone growth stimulator sensors, or a combination thereof. In one aspect, the plurality of contact sensors can include four, five, six, seven, eight, nine, or ten or more contact sensors surrounding each transmitter or receiver.

[0276] Figure 23A and 23BDepicted is an example of how comparison of perfusion values ​​associated with receivers of known relative positions can identify bilaterally symmetrical locations in accordance with the present disclosure. In this example, at contact site 2050R of right foot 20R, Figure 23A The receivers 430 are presented at non-overlapping locations labeled "A" through "H" in FIG. The perfusion values ​​measured at each location are Figure 23B 20R . In this example, the perfusion values ​​for locations "A" and "H" are low or zero, reflecting that the receiver 430 does not overlap with the contact site 2050R at those locations. The perfusion values ​​associated with locations "B" and "G" are higher because the receiver 430 overlaps a portion of the contact site 2050R at those locations. The perfusion values ​​for locations CDEF are higher and, in this example, approximately the same, indicating that the receiver 430 is completely within the contact site 2050R at those locations. In one aspect, a perfusion measurement device such as device 400 can determine that certain locations, such as locations "C" and "F," are bilaterally symmetric relative to the centerline 2052R of the right foot 20R. In one aspect, a similar set of measurements taken at locations A'-H' on the left foot 20L can determine that locations on each of feet 20L and 20R, such as locations E and E', are approximately bilaterally symmetric.

[0277] Figure 24 A schematic diagram of an integrated system 2100 for measuring, evaluating, storing, and transmitting perfusion values ​​according to the present disclosure is depicted. In this example, the system 2100 includes Figure 4 The perfusion measurement device 400 discussed herein has the capability to wirelessly communicate with a WiFi access point 2110. The device 400 communicates with one or more of a perfusion application running on a server 2140, an application running on a laptop 2120, a smartphone 2130, or other digital device. In one aspect, the laptop 2120 and smartphone 2130 are carried by a user of the device 400 (e.g., a nurse), and the application provides feedback and information to the user. In one aspect, information about the patient received from the device 400 is stored in a database 2150. In one aspect, the information received from the device 400 is transmitted via a network 2145 to another server 2160, which stores a portion of the information in the patient's electronic medical record (EMR) 2170. In one aspect, the information from the device 400 or information retrieved from the database 2150 or the EMR 2170 is transmitted to an external server 2180 and then to a computer 2185, such as a computer in the office of a physician providing care for the patient.

[0278] Trend analysis of perfusion measurements to detect tissue damage

[0279] Figure 25Perfusion values ​​over time are depicted for a patient at risk for developing a pressure sore according to the present disclosure. In one aspect, the perfusion value is a single perfusion measurement. In one aspect, the perfusion value is an average perfusion measurement generated from perfusion measurements taken at approximately the same location on the patient's skin over a 24-hour period (such as within 18 hours, 12 hours, 8 hours, 6 hours, 4 hours, 3 hours, 2 hours, 1 hour, 45 minutes, 30 minutes, 15 minutes, 10 minutes, 5 minutes, 1 minute, or 30 seconds).

[0280] Curve 2210 represents the average perfusion values ​​for a group of patients at high risk of developing a pressure ulcer during the days leading up to the development of a pressure ulcer on day 0. The overlaid straight lines are linear approximations. Curve 2220 represents the average perfusion values ​​for a group of patients at low risk of developing a pressure ulcer during the days prior to day 0, where no pressure ulcer developed on day 0. In both cases, there was no sign of damage or indication of future development of a pressure ulcer on the skin. The perfusion values ​​indicate subsurface damage (e.g., changes in elasticity or temperature) that is not visible to visual and tactile inspection. The overlaid straight lines are linear approximations.

[0281] Figure 26 Depicted are perfusion delta values ​​over time for patients who developed pressure ulcers according to the present disclosure. Curves 2302 and 2304 illustrate the acceleration of the rate of increase (i.e., slope) of the curves as time approaches the point at which visual inspection leads to a clinical diagnosis. Curve 2310 is the average of the other curves and illustrates an upward curve, i.e., an acceleration of the rate of increase.

[0282] Figure 27 24 is an example graph of measured and calculated perfusion values ​​according to the present disclosure. Curve 2410 is a set of perfusion values ​​for a skin site susceptible to developing a pressure ulcer. Curve 2420 is a matched set of perfusion values ​​for a second skin site that is adjacent to the first site but not at risk for developing a pressure ulcer. Curve 2420 serves as a reference. Curve 2430 is a "delta" perfusion value calculated by subtracting the reference value of curve 2420 from the matched perfusion value of curve 2410.

[0283] Tissue damage can be detected in several ways. In one aspect, the slope of perfusion curve 2410, such as the slope between points 2414 and 2416, is compared to a threshold slope indicated by line 2412. If the slope of curve 2410 exceeds the slope of line 2412, a certain degree of damage is indicated. Multiple slopes may be used to assess various degrees of tissue damage. In one aspect, a slope is determined relative to any two points on perfusion curve 2410 and compared to the slope of line 2412 to indicate a certain degree of damage. In one aspect, the slope is determined by taking the derivative of perfusion curve 2410. In one aspect, the slope of line 2412 is determined based on the subject's health history. In one aspect, the curvature of the perfusion curve is compared to a threshold curvature, where a curvature that is too high indicates a certain degree of damage.

[0284] In one aspect, tissue damage can be detected before it is visible on the patient's skin by: measuring multiple SpO2 values ​​at a single location at incremental times; calculating the slope between the most recent SpO2 value and the immediately previous SpO2 value; comparing this slope to a threshold; and if the slope exceeds the threshold, determining that tissue damage is present.

[0285] In one aspect, tissue damage can be detected before it is visible on the patient's skin by: measuring multiple SpO2 values ​​at a single location at incremental times; calculating a derivative between the most recent SpO2 value and the immediately previous SpO2 value; comparing this derivative to a threshold; and determining that tissue damage is present if the derivative exceeds the threshold.

[0286] In one aspect, the value of delta curve 2430 is compared to a threshold level 2438. When curve 2430 exceeds threshold 2438, such as at point 2436, a certain degree of damage is indicated. There may be multiple thresholds for assessing various levels of tissue damage.

[0287] In one aspect, tissue damage can be detected before it is visible on the patient's skin by: measuring multiple SpO2 values ​​at a single location at each of multiple incremental times; calculating an average for each incremental time; fitting a curve to a predetermined number of the most recent SpO2 averages; calculating the curvature of the fitted curve; comparing this curvature to a threshold; and determining that tissue damage is present if the curvature exceeds the threshold.

[0288] In one aspect, the threshold value can be about 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3 , 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.0, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, 5.0, 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8, 5.9, 6.0, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9, 7.0, 7.1, 7.2, 7.3, 7.4 or 7.5. In one aspect, the threshold value can be in the range of 0.1 to 8.0, such as 0.1 to 1.0, 1.1 to 2.0, 2.1 to 3.0, 3.1 to 4.0, 4.1 to 5.0, 5.1 to 6.0, 6.1 to 7.0, 7.1 to 8.0, 0.1 to 7.5, 0.5 to 8.0, 1.0 to 7.0, 1.5 to 6.5, 2.0 to 6.0, 3.0 to 5.5, 3.5 to 5.0, or 4.0 to 4.5. In one aspect, the threshold value can be scaled by a factor or multiple based on the values ​​provided herein. It should be understood that the threshold value is not limited by design, but rather, one of ordinary skill in the art will be able to select a predetermined value based on a given perfusion unit. In one aspect, the threshold value of the present disclosure varies depending on the specific part of the patient's body on which the measurement is made or one or more characteristics of the patient (such as age, height, weight, family history, race, and other physical characteristics or medical conditions).

[0289] In one aspect, the slope of delta curve 2430, such as the slope between points 2434 and 2436, is compared to a threshold slope indicated by line 2432. If the slope of curve 2430 exceeds the slope of line 2432, a certain degree of damage is indicated. Multiple slopes may be used to assess various degrees of tissue damage. In one aspect, a slope is determined relative to any two points on delta curve 2430 and compared to the slope of line 2432 to indicate a certain degree of damage. In one aspect, the slope of line 2432 is determined based on the subject's health history. In one aspect, the curvature of the delta curve is compared to a threshold curvature, where a curvature that is too high indicates a certain degree of damage.

[0290] In one aspect, a perfusion delta value above a predetermined threshold indicates subepidermal damage that may lead to a pressure sore. When the perfusion delta value increases linearly, the time interval between when the perfusion delta value first equals or exceeds the threshold and when visible symptoms of the pressure sore develop can be a first duration. The first duration can be 5 or more days, such as 6 or more days, 7 or more days, 8 or more days, 9 or more days, or 10 or more days.

[0291] On the other hand, when the perfusion delta curve exhibits an upward bend or other deviation from a linear progression, visible symptoms may develop within a shorter timeframe, such as 2-3 days, 1-4 days, 1-3 days, 1-2 days, or 2-4 days. In one aspect, a perfusion measurement device 400 is configured to generate perfusion delta values ​​for a specific location on a patient's skin (e.g., the heel). The device includes a receiver 430 and electronics to measure reflected light, convert this reflected light measurement into a perfusion value, and store a plurality of these perfusion values. A perfusion delta value is then calculated and displayed based on the plurality of perfusion values, and a portion of the measurement and delta value is transmitted to a remote computer. These perfusion delta values ​​are tracked and analyzed for trends, i.e., the slope and curvature of a curve connecting these perfusion delta values. In one aspect, the amount by which an incremental perfusion delta value exceeds a linear prediction based on previous perfusion delta values ​​is compared to a predetermined threshold. In one aspect, the amount by which an incremental perfusion delta value exceeds a most recent previous perfusion delta value is compared to a predetermined threshold. In one aspect, the curvature of a best-fit curve fitted to a predetermined number of most recent perfusion delta values ​​is compared to a predetermined threshold. In one aspect, the number of sequential perfusion delta values ​​exceeding a predetermined value threshold is compared to a reading number threshold. In each of these aspects, the perfusion scanner issues a notification when the compared parameter exceeds the respective threshold.

[0292] In one aspect, the trend analysis may disregard a single perfusion delta value that is below the threshold if both the previous and subsequent perfusion delta values ​​are above the threshold.

[0293] In one aspect, the trend curve of the perfusion delta values ​​is a point-to-point linear connection. In one aspect, the trend curve is a best fit curve fitted to the perfusion delta values. In one aspect, the fitted curve needs to intersect the most recent perfusion delta value.

[0294] Having now generally described this invention, the same will be understood more readily by reference to the following examples which are provided by way of illustration and are not intended to limit the disclosure unless otherwise specified.

[0295] Examples

[0296] Example 1: Levels of intervention for treating heel pressure ulcers

[0297] Subjects identified as at risk for heel pressure ulcers were treated according to the following protocol:

[0298] Table 1: Example intervention protocols for treating heel pressure ulcers

[0299]

[0300]

[0301] Example 2: Levels of intervention for treating sacral pressure ulcers

[0302] Subjects identified as at risk for sacral pressure ulcers were treated according to the following protocol:

[0303] Table 2: Example intervention protocols for treating sacral pressure ulcers

[0304]

[0305] Example 3: Example process for selecting intervention and monitoring levels

[0306] Figure 15 15 is an illustration of a process 1500 for selecting an intervention and monitoring level based on the amount by which a delta value derived from a perfusion measurement exceeds a threshold. Here, in step 1502, a caregiver takes multiple perfusion measurements at a location on a patient's skin, each of which produces a perfusion value. Using a portion of these perfusion values, a delta value "delta" is calculated in step 1504. The delta value is calculated by subtracting the minimum perfusion value from the maximum perfusion value generated by the multiple perfusion measurements.

[0307] In step 1506, the calculated delta value is compared to a threshold value "T". If the delta value is less than or equal to the threshold, step 1508 is executed and the caregiver waits until the monitoring interval associated with the current level of care occurs and then repeats the perfusion measurement in step 1502. If the delta value is greater than the threshold, the amount by which the delta value exceeds the threshold is compared to a series of cascaded difference values.

[0308] In some cases, the Δ value is positive, and a comparison is performed by subtracting a threshold from the Δ value to produce a positive difference, and then determining whether the difference exceeds a first difference D1 in step 1510. If the difference is less than D1, the process proceeds to step 1512 and then to step 1514 to implement the intervention and measurement interval associated with level N+1, respectively. In this example, the value of N is zero or greater.

[0309] In some cases, the delta value is negative. In this case, the differences D1, D2 to Dn are selected to have negative values, which may have different absolute values ​​than the corresponding differences D1, D2 to Dn for positive delta values. Alternatively, the comparisons in steps 1510, 1520, and 1530 are changed to "≤" to replace Figure 15 The “≥” shown in .

[0310] Example 4: Workflow Guidance Matrix

[0311] Figure 16 Figure 16 is an example of a workflow guidance matrix 1600, where the current intervention level 1602 and the new delta value 1604 are used to select a new intervention level 1606. Here, a caregiver monitors a patient's condition by periodically taking multiple perfusion measurements at one or more locations on the patient's skin. While taking these measurements, the patient receives care associated with an intervention and monitoring level. In this example, level 0 (zero) is associated with patients deemed not at risk for developing tissue damage. Higher intervention and monitoring levels can be determined by ranking the intervention levels, for example, based on cost, implementation difficulty, or other parameters determined by the care provider. When a caregiver takes a new set of perfusion measurements, they query this matrix by identifying the row for the current intervention level 1602, the delta value determined from the most recent set of perfusion measurements 1604, and identifying the intervention level 1606 in the cell at the intersection of row 1602 and column 1604. When selecting the intervention level for the next time period, the caregiver can consider the determined intervention level, as well as the current intervention level and delta value.

[0312] In some cases, the values ​​of the new intervention levels in cells 1606 are similar row by row. In some cases, the values ​​of the new intervention levels in adjacent cells 1606 differ by a single level or by more than one level. In some cases, the values ​​of the new intervention levels in adjacent cells 1606 are the same in the adjacent cells.

[0313] Example 5: Progression of tissue conditions leading to wound development

[0314] Figure 17 Schematic diagram 1700 shows delta values ​​for a single patient at a single location of wound development. Perfusion values ​​are measured by a device for evaluating blood perfusion in tissue beneath the patient's skin. Delta values ​​are generated based on a set of perfusion measurements taken at incremental times. Point 1772 is a measurement at time t=0, where all perfusion values ​​have baseline values ​​associated with healthy tissue and the delta value is zero. At time t1, another set of perfusion measurements is taken, and the associated delta value is indicated at point 1774. This delta value is below threshold 1762, thus indicating no significant subsurface injury.

[0315] At time t2, the damage has progressed and the delta value 1776 is greater than the threshold 1762, indicating the presence of significant damage. This damage is still not visible on the skin. Nevertheless, the delta value greater than the threshold 1762 indicates the presence of cellular damage at a depth less than the sensitive depth of the perfusion measurement device.

[0316] At time t3, the injury continues, but the amount of fluid in the interstitial space decreases due to mechanical drainage. Since the perfusion value of healthy tissue remains approximately the same as during the previous measurement, this reduces the perfusion value obtained above the injured site, thereby reducing the calculated delta value 1778.

[0317] At time t4, the lesion has progressed to the point where it is visible on the skin surface. In some cases, time t4 may occur before one or both of t2 and t3. In some cases, time t4 may occur after the delta value reaches zero again along curve 1770 after time t3 and before t5. Arrow 1765 indicates that after time t4, the lesion is still visible.

[0318] At time t5, the injury has progressed to the point where enough fluid has been drained from the local tissue so that the perfusion value measured above the injury site is lower than that of healthy tissue. This results in a negative delta value 1780. In some cases, a negative delta would indicate that the tissue is severely damaged. In some cases, a negative delta would indicate that the portion of tissue at the location of the lowest perfusion value is necrotic.

[0319] Example 6: Method I for Mapping Potential Injury Sites

[0320] Figure 18A 18 is an example of a method for mapping areas of potential injury. Injured area 1800 is surrounded by healthy tissue 1808. A central area 1830 is severely damaged. A first peripheral area 1820 has less damage, and a second peripheral area 1810 has less damage, but is still non-healthy tissue. The skin over all of these areas has the same appearance and texture, with no indication of subsurface injury. A series of dashed circles 1840, 1842, 1844, 1846, 1848, and 1850 indicate a set of example locations where perfusion measurements are taken. Perfusion measurements taken at locations 1840, 1842, and 1850 typically produce perfusion values ​​associated with healthy tissue, designated "H" in this example. Perfusion measurements taken at locations 1844 and 1848 typically produce perfusion values ​​"J" slightly higher than H. Perfusion measurements taken at location 1846 typically produce perfusion values ​​"P" greater than J. These measurements can be taken at a single "location" on the patient's body (e.g., the sacrum), even if the locations are spatially dispersed above this location. For this set of perfusion values, Δ is the difference between the highest perfusion value in the set (which may occur at location 1846) and the lowest perfusion value (which may occur at one of locations 1840, 1842, and 1850). If Δ is greater than a threshold value "T," then this indicates the presence of a significant lesion at that location. The exact location of the largest lesion may be close to the measurement location 1846 that produced the maximum perfusion value.

[0321] Example 7: Method II for Mapping Potential Injury Sites

[0322] Figure 18B A second example of mapping a possible lesion is depicted. In this example, based on the previous application Figure 18A The method shown determines the approximate location of the largest lesion. The purpose of this method is to map the boundary between site 1810 and site 1820 to determine the extent of the lesion. For simplicity, the perfusion values ​​generated by the measurements at each site are the same, and the perfusion values ​​increase from site 1810 to site 1820 and then to site 1830. The first perfusion measurement is made at location 1860, which is known to be the approximate location of the largest lesion. Subsequent measurements are made at locations 1862, 1864, 1866, and 1868 in the order indicated by path 1880. The perfusion value generated at location 1864 is slightly higher than the perfusion values ​​generated at locations 1862 and 1866, indicating that location 1864 is partially within site 1820, while locations 1862 and 1866 are completely within site 1810, where the lesion is smaller. The boundary can be approximated by interpolating between the various measurement locations. For example, the perfusion value generated at location 1870 is high enough to indicate that it is completely within site 1820 and therefore does not help identify the boundary between sites 1810 and 1820. Therefore, subsequent location 1872 is directly away from starting location 1860. Since location 1860 is now completely within site 1810 in this example, the boundary between sites 1810 and 1820 can be interpolated between locations 1870 and 1872. The measurement at location 1874 generates a perfusion value similar to that of location 1870 and is sufficient to identify the boundary as being outside of location 1874 without requiring another measurement at the location corresponding to location 1872.

[0323] This set of measurements enables creation of a map of a certain level of injury, such as site 1820. Repeating this mapping process at regular intervals will provide an indication of whether site 1820 is growing (which may indicate that an increased level of intervention is appropriate) or shrinking (which may indicate that the current level of intervention is healing the injury).

[0324] Example 8: Treatment decision pathway for stratifying patients and providing appropriate treatment

[0325] Figure 19AThis article summarizes the currently recommended treatment decision pathway for preventing pressure ulcers in hospitalized patients, as outlined by the National Institute for Health and Care Excellence (NICE) in its clinical guideline, Pressure ulcers: prevention and management (published April 23, 2014). The guideline recommends a risk analysis for every patient admitted to a nursing facility who exhibits one or more risk factors, such as significant limitation of mobility, significant loss of sensation, a previous or current pressure ulcer, poor nutrition, inability to reposition oneself, or significant cognitive impairment. Risk assessment is typically performed using a scoring checklist, such as the Braden scale, which rates the severity of specific risk factors.

[0326] After completing the risk assessment, patients are identified as (i) at low risk for developing a pressure ulcer, (ii) at risk for developing a pressure ulcer, or (iii) at high risk for developing a pressure ulcer. Depending on the patient's risk level, they will receive different treatment and visual assessment sequences.

[0327] All people are at risk of developing pressure sores. They are more likely to develop in people who are seriously ill or who have neurological disorders, mobility impairments, poor nutrition, poor posture, or deformities.

[0328] Pressure ulcers are classified as Stage 1 to Stage 4, with Stage 1 being the mildest. The National Pressure Ulcer Advisory Panel (NPUAP) has defined a "Stage 1" ulcer as intact skin with a localized area of ​​nonblanchable erythema, where "blanchable" means the tissue loses all red color when pressure is applied, while "nonblanchable" tissue remains red when pressure is applied due to the presence of red blood cells outside of blood vessels (extravasation). In some patients, the appearance of a nonblanchable erythema, or a change in sensation, temperature, or firmness, may precede a visual change.

[0329] Visual skin assessment (VSA) is the current method for identifying pressure ulcers. Trained healthcare professionals visually and tactilely assess the appearance of the skin, looking for redness, or changes in tissue firmness, temperature, or moisture.

[0330] If a patient is identified as being at low risk for developing a pressure ulcer, they will only need to be monitored for changes in their clinical status, such as surgery, worsening of underlying medical conditions, or changes in mobility. Patients who use a wheelchair or sit for extended periods of time may be provided with a high-profile foam cushion or equivalent pressure-distributing cushion. If there is no change in clinical status, the low-risk patient will not be re-evaluated according to these guidelines and will remain on the same treatment and assessment pathway until they are discharged from the healthcare facility.

[0331] If a patient is identified as being at risk of developing a pressure ulcer, the plan is to turn or 'roll' the patient every 6 hours. As with low-risk patients, high-spec foam padding can be provided if the patient uses a wheelchair or sits for extended periods. NICE guidelines do not recommend other monitoring or interventions.

[0332] High-risk patients receive a high-specification foam mattress as a precautionary measure. If they use a wheelchair or sit for extended periods, they are provided with a high-specification cushion and are turned every four hours. Patients undergo daily VSA of all body areas. If a site is found to have nonblanchable erythema, appropriate intervention is implemented, and the site is re-examined by VSA every two hours. Sites without nonblanchable erythema are re-examined daily by VSA. A personalized care plan is developed for each high-risk patient.

[0333] As can be seen from this flowchart, caregivers will spend the majority of their time with high-risk patients. While this may be appropriate, it results in at-risk patients going unmonitored, and they may develop a Stage 1 ulcer before caregivers recognize the condition. Furthermore, the consequence of relying on VSA to detect problems inevitably means that patients will develop a Stage 1 ulcer before intervention is selected or administered. By the time the lesion progresses to Stage 1, even with intervention, the skin may still break down and become a Stage 2 ulcer. Clearly, early identification of tissue damage is necessary so that intervention can prevent subepidermal lesions from progressing to Stage 1 and worse.

[0334] Figure 19B This is an example of a current enhanced treatment decision pathway for pressure ulcer prevention currently being implemented in some healthcare settings. The enhanced pathway adds monitoring steps to both at-risk and low-risk pathways. Low-risk patients undergo weekly risk assessments, such as completing the Braden Scale. Patients identified as at-risk during the initial assessment receive a high-specification foam mattress as a preventative measure and are assessed daily via the VSA. A care plan is developed to monitor and treat at-risk patients. For high-risk patients, no changes are made to their care.

[0335] The benefit of an enhanced program is that all patients can be monitored for pressure ulcers on a basic basis. However, the additional steps will in any case require additional time, additional staff, or further burden existing staff. Although better than Figure 19A The recommended care pathway, but Figure 19B The current care pathway requires more resources and remains limited by the fact that patients must develop a stage 1 ulcer before the injury is recognized by VSA.

[0336] Hospitals and nursing facilities use a different number of risk categories, ranging from two categories, low risk and high risk, to four or more categories. Figure 19BPatients are assigned to categories based on the results of the initial risk assessment.

[0337] Figure 20 is an example flow chart according to the present disclosure that shows how a device for evaluating blood perfusion in tissue beneath a patient's skin can be used in a standalone process to prevent pressure ulcers. Each patient admitted to the hospital receives a complete perfusion evaluation of all body locations selected for monitoring. These selected locations can include sites recommended in the instructions for use (IFU) for the perfusion measurement device, such as the sacrum and heel. The hospital can identify other locations and integrate them into its internal practice. Multiple perfusion measurements are taken at separate locations at and around each body location, although this is generally referred to as taking multiple measurements at the body location. The perfusion measurement device calculates a "Δ" value for each location based on a set of measurements taken at and around that location. The Δ value is then compared to one or more thresholds to classify the patient. In this example, the patient is assigned one of two risk categories: low risk and at risk.

[0338] In one aspect, the clinician will perform perfusion measurements at a first time interval on body locations identified as potentially having lesions in an initial set of perfusion measurements. The clinician will also perform perfusion measurements at a second time interval that is longer than the first time interval on all other body locations selected for monitoring. In one aspect, the values ​​of the first and second time intervals vary depending on the risk category assigned to the patient. For example, a high-risk patient will have a first time interval of 4 hours and a second time interval of 1 day, while an at-risk patient will have a first time interval of 1 day and a second time interval of 1 week. In one aspect, the time intervals can be event-based, such as based on a change in attendance or a shift change, rather than strictly time-based. Typically, body locations with elevated Δ values ​​will be scanned more frequently than other body locations that were monitored in previous perfusion measurements but had normal Δ values.

[0339] In one aspect, the interval at which perfusion measurements are performed is determined by a delta value from a previous perfusion measurement. For example, perfusion measurements are performed at a first time interval for a body location having a delta value greater than or equal to a first threshold value in a previous perfusion scan, and perfusion measurements are performed at a second time interval shorter than the first time interval when the delta value of the previous perfusion measurement for the body location is greater than or equal to a second threshold value (the second threshold value is greater than the first threshold value).

[0340] In this example, low-risk patients receive weekly perfusion scans of all body locations selected for monitoring. Because weekly perfusion scans are likely to detect tissue damage before VSA is visible, basic protection can be provided to even the healthiest patients without much effort.

[0341] Patients at risk (will be included in Figure 19A and 19B Patients identified as high risk in the current care pathway will receive specialized care based on the body position exhibiting a delta value above a threshold. For example, if the delta value for the sacrum body position is above a threshold, the patient will be repositioned every 6 hours and receive perfusion measurements at the sacrum daily, and at other body positions weekly.

[0342] Figure 21 is an example flow chart according to the present disclosure showing how a device for evaluating blood perfusion in tissue beneath a patient's skin can be used as an aid to further improve Figure 19B An enhanced treatment decision pathway is presented. Patients admitted to a hospital undergo risk assessments and perfusion scans of all body locations determined by the hospital for monitoring, and the patient's risk category is assigned based in part on the risk assessment and in part on the perfusion scan results. An initial delta value greater than a threshold indicates the potential presence of an injury at that body location. In one aspect, the assignment is based solely on the maximum initial delta value found during the initial perfusion scan.

[0343] The decision whether to perform an intervention, such as turning the patient at a first time interval, is currently based on the VSA and risk assessment, despite uncertainty about whether an early-stage injury exists beneath the skin. In one aspect, the decision to perform an intervention targeted at a specific body location or a general intervention, such as a high-specification mattress, is based on the Δ value found for that location in the perfusion scan. If the Δ value is less than a predetermined threshold, no intervention is required. If the Δ value is greater than a predetermined threshold, an intervention is selected and performed based in part on the body location and in part on the Δ value for that body location. The predetermined threshold for determining whether to select and perform an intervention can be higher or lower than the threshold for determining the possible presence of an injury at a body location.

[0344] Compare Figure 19A 、 19B , 20, and 21, demonstrating one of the benefits of using perfusion measurement devices to monitor patients. It is important to note that the costs quoted here are for patients who do not have or do not develop pressure ulcers, in which case the estimated cost of treating a stage 1 ulcer jumps to

[0345] The baseline for this comparison is Figure 19B Current Enhanced Practices, which represents current “best practices” for hospitals striving to reduce pressure ulcer rates. For care provided in the low-risk care pathway, the average length of stay was expected to be 5.6 days, with an average cost per patient of The cost of care for patients at risk is estimated to be an average Costs for high-risk patients are estimated to be All care pathways relied on the VSA to detect pressure ulcers and implemented interventions based on the progression of a ‘typical’ patient rather than the specific patient's condition.

[0346] like Figure 21 As shown, integrating perfusion measurement devices into current "best practice" workflows does not reduce the cost of any care pathway because no work elements are eliminated. The benefit is the ability to detect tissue damage at an early stage with minimal incremental cost. The incremental cost of adding perfusion scanning to a no-risk care pathway is This reduces the cost from approximately Increase to The expected cost of care for at-risk patients without any elevated perfusion delta values ​​(i.e., without subepidermal tissue damage) also increases by only However, if an at-risk patient is found to have an elevated perfusion delta value, the patient is upgraded to a high-risk category where the expected cost of care decreases from Increase to While it may seem like a small additional cost, it provides an added level of protection for at-risk patients.

[0347] Figure 20 represents an example workflow that relies solely on perfusion measurement devices to monitor patients and forgoes routine VSA. The expected cost of preventive care for low-risk patients is and Figure 21 The cost of a comprehensive low-risk care pathway is For patients at risk (who are Figure 20 The only other category in the perfusion measurement device care pathway) with an expected cost of and Figure 21 The cost of integrated care pathways for at-risk and high-risk patients is

[0348] Example 9: Perfusion A trend in a patient's heel indicates a pressure ulcer onset

[0349] Before any visual diagnosis of a pressure ulcer on the heel is performed, perfusion measurements are taken at the patient's heel time using a device according to the present disclosure. At each time point, each patient is guided with the toes turned away from the body and outward toward the side of the body. The receiver of the perfusion detection device is placed on the inside of the heel. The receiver is adjusted to make full contact with the heel and multiple measurements are taken in a curved line around the back of the heel. Each reflected light measurement is converted to a perfusion delta value by subtracting from the measurement a reference perfusion value obtained from another body part of the same patient that is not subjected to external pressure or mechanical forces. The perfusion delta values ​​obtained over the course of the day are averaged and plotted for each patient.

[0350] Figure 28The perfusion delta values ​​for seven (7) patients are shown before they were diagnosed with one or both heels developing a pressure ulcer. Following the pressure ulcer diagnosis event, the trends for the different patients were time-shifted to coincide with day 0. A reference perfusion delta curve ("mean-H") was generated by averaging the perfusion delta value trends for all patients (n=20) who were ultimately visually diagnosed with a heel pressure ulcer. Figure 28 As shown, these seven patients exhibited peak perfusion delta values ​​two (2) to four (4) days before visual diagnosis compared to the reference curve. For these patients, the slope of the perfusion delta value trend was steeper compared to the reference curve, indicating that the pressure ulcer developed earlier, prior to any visual detection.

[0351] Example 10: Intervention Levels Based on Oxygenation Measurements

[0352] Subjects identified as at risk for pressure ulcers were treated according to the following protocol:

[0353] Table 3: Example intervention options for treating patients at risk for pressure ulcers

[0354]

[0355] From the foregoing, it will be appreciated that the present invention can be implemented in a variety of ways, including but not limited to the following:

[0356] Example 1. A device for evaluating blood perfusion in tissue beneath the skin of a patient, comprising: a transmitter configured to emit light of a first wavelength and a second wavelength when activated; a first receiver configured to measure a first intensity of the received light of the first wavelength and a second intensity of the received light of the second wavelength, and to provide a first signal including information about the first and second intensities of the received light; a substrate coupled to the transmitter and the first receiver and configured so that the transmitter and the first receiver can be placed in contact with the patient's skin simultaneously; and a processor coupled to the first receiver and configured to: receive the first signal, determine a first sum value of the first and second intensities of the received light, and determine the perfusion level of the tissue based on the first sum value.

[0357] Example 2. The apparatus of Example 1, wherein the first receiver is spaced apart from the transmitter by a first distance, the first distance being selected such that light emitted by the transmitter and received by the first receiver is reflected from a first depth below the patient's skin.

[0358] Example 3. The device according to Example 1 or 2 further includes a second receiver, wherein: the second receiver is separated from the transmitter by a second distance, the second distance is selected so that the light emitted by the transmitter and received by the second receiver is reflected from a second depth below the patient's skin, the second receiver is configured to: measure a third intensity of the received light of the first wavelength, measure a fourth intensity of the received light of the second wavelength, and provide a second signal including information about the third and fourth intensities of the received light; and the processor is coupled to the second receiver and is configured to: receive the second signal, determine a fifth intensity of the received light by subtracting the third intensity from the first intensity, determine a sixth intensity of the received light by subtracting the fourth intensity from the second intensity, determine a second sum value of the fifth and sixth intensities, and determine the perfusion level of the tissue between the first depth and the second depth based on the second sum value.

[0359] Embodiment 4. The apparatus of any one of embodiments 1 to 3, wherein the first wavelength is associated with a peak absorption wavelength of oxygenated hemoglobin and the second wavelength is associated with a peak absorption wavelength of deoxygenated hemoglobin.

[0360] Embodiment 5. The apparatus of any one of Embodiments 1 to 4, wherein the emitter comprises a first source emitting light at the first wavelength and a second source emitting light at the second wavelength.

[0361] Embodiment 6. The device of Embodiment 5, wherein the first source and the second source can be activated independently.

[0362] Embodiment 7. The apparatus of any one of Embodiments 1 to 6, wherein the receiver comprises a first detector that senses light at the first wavelength and a second detector that senses light at the second wavelength.

[0363] Embodiment 8. The apparatus of embodiment 7, wherein: the processor is individually coupled to each of the first and second detectors, and the first signal comprises individual signals from the first and second detectors.

[0364] Embodiment 9. The apparatus of any one of embodiments 1 to 8, wherein: the processor is coupled to the transmitter, the transmitter is configured to emit light upon receiving a strobe pulse, the processor is configured to provide the strobe pulse to the transmitter and the first receiver, the first receiver is further configured to measure a first time period between receiving the strobe pulse and receiving light from the transmitter, and the first signal includes information about the first time period.

[0365] Embodiment 10. The apparatus of any one of embodiments 1 to 9, further comprising a memory coupled to the processor, wherein the processor is configured to store a series of sum values ​​associated with sequential activations of the transmitters in the memory.

[0366] Embodiment 11. The apparatus of embodiment 10, wherein the processor is further configured to determine a range between a minimum sum value and a maximum sum value in the series of sum values.

[0367] Embodiment 12. The apparatus of embodiment 10, wherein the processor is further configured to determine a percentage value for each sum value relative to a maximum sum value in the series of sum values.

[0368] Embodiment 13. The device of any one of embodiments 1 to 12, further comprising an accelerometer configured to provide a third signal comprising information about the acceleration of the device in three spatial dimensions, wherein: the processor is coupled to the accelerometer and configured to receive the third signal, and the processor is further configured to determine the spatial position of the transmitter when the transmitter is activated.

[0369] Example 14. A method for evaluating blood perfusion in tissue beneath the skin of a patient, the method comprising the following steps: emitting light to the patient's skin at a first location on the patient's skin, the light comprising a first wavelength and a second wavelength; receiving a portion of the emitted light that has been reflected from the tissue; measuring a first intensity of the received light of the first wavelength and a second intensity of the received light of the second wavelength; and determining a first sum value of the first and second intensities of the received light.

[0370] Example 15. The method according to Example 14 further includes the following steps: repeating the step of emitting light, receiving a portion of the emitted light and measuring the first and second intensities of the received light at a second position on the patient's skin; determining a second sum value of the first and second intensities of the received light associated with the second position; and determining a Δ value between the first sum value and the second sum value.

[0371] Example 16. The method according to Example 14 further includes the following steps: repeating the step of emitting light, receiving a portion of the emitted light and measuring the first and second intensities of the received light at multiple locations on the patient's skin; determining multiple sum values ​​of the first and second intensities of the received light associated with the corresponding multiple locations; identifying a maximum sum value from the multiple sum values; and determining a Δ value between the maximum sum value and at least one of the multiple sum values.

[0372] Example 17. A device for evaluating blood perfusion in tissue beneath the skin of a patient, comprising: an emitter configured to selectively emit light of a first wavelength or emit light of a second wavelength; a camera configured to form a first image of reflected light of the first wavelength and a second image of reflected light of the second wavelength; a substrate coupled to the emitter and the camera and configured such that the substrate can be positioned so that the light emitted by the emitter illuminates a portion of the patient's skin within the field of view of the camera; a display; and a processor coupled to the camera and the display and configured to: receive the first and second images, form a third image that is the sum of the first and second images, and provide the third image to the display.

[0373] Embodiment 18. The apparatus of embodiment 17, wherein: the processor is coupled to the emitter, the processor being further configured to cause the emitter to emit only light of the first wavelength at a first time and only light of the second wavelength at a second time; and the camera forms the first image at the first time and forms the second image at the second time.

[0374] Example 19. A method for identifying and treating a patient requiring wound treatment, the method comprising the following steps: assessing the patient's risk of tissue damage when the patient is admitted to a nursing facility, wherein the assessment comprises: performing a first plurality of perfusion measurements in the patient; calculating a first Δ value based on a portion of the first plurality of perfusion measurements; determining whether the first Δ value exceeds a first threshold; if the first Δ value does not exceed the first threshold, applying a level 0 first intervention; and if the first Δ value exceeds the first threshold, applying a level N first intervention, wherein N is an integer and the value of N is 1 or greater.

[0375] Example 20. A method according to Example 19, wherein the step of performing a first plurality of perfusion measurements comprises performing each perfusion measurement using a perfusion measurement device and generating a corresponding perfusion value, and the step of calculating a first Δ value comprises comparing perfusion values ​​generated by a portion of the first plurality of perfusion measurements.

[0376] Example 21. A method according to Example 19, wherein the step of performing a first plurality of perfusion measurements comprises: performing a first subset of perfusion measurements at the first location and performing at least one additional subset of perfusion measurements at the second location; the step of calculating a first Δ value comprises: calculating the first Δ value for the first location based on a portion of the measurements of the first subset, and calculating the first Δ value for the second location based on a portion of the measurements of the second subset; the step of determining whether the first Δ value exceeds a first threshold comprises: determining whether the first Δ value for the first location exceeds a first threshold for the first location, and determining whether the first Δ value for the second location exceeds a first threshold for the second location; the step of applying a level 0 first intervention comprises: applying a first location-specific level 0 intervention if the first Δ for the first location does not exceed the first threshold for the first location, and applying a second location-specific level 0 intervention if the first Δ for the second location does not exceed the first threshold for the second location; and the step of applying a level N first intervention comprises: applying a first location-specific level N intervention if the first Δ for the first location exceeds the first threshold for the first location, and applying a second location-specific level N intervention if the first Δ for the second location exceeds the first threshold for the second location.

[0377] Embodiment 22. The method of embodiment 19, wherein the evaluating step further comprises performing a visual assessment.

[0378] Embodiment 23. The method of embodiment 22, wherein the patient has no visible symptoms of the wound.

[0379] Embodiment 24. The method of embodiment 19, wherein the evaluating step further comprises performing a risk assessment.

[0380] Embodiment 25. The method of embodiment 19, wherein the value of N is equal to 1.

[0381] Embodiment 26. The method of embodiment 19, wherein the value of N is 2 or greater based on the amount by which the first delta value exceeds the first threshold.

[0382] Embodiment 27. The method of embodiment 19, wherein the value of N does not exceed 10.

[0383] Embodiment 28. The method of Embodiment 19, wherein the Level N first intervention is a more intensive intervention than the Level 0 first intervention.

[0384] Example 29. The method according to Example 19 further includes the following steps: performing a second plurality of perfusion measurements in the patient at a first predetermined frequency corresponding to the level of intervention applied; calculating a second Δ value based on a portion of the second plurality of perfusion measurements, and determining whether the second Δ value exceeds a second threshold; continuing to apply the first intervention if the second Δ value does not exceed the second threshold; continuing to perform multiple perfusion measurements at the first predetermined frequency if the second Δ value does not exceed the second threshold; applying a second intervention of level M if the second Δ value exceeds the second threshold, where M is an integer and M is greater than N; and performing multiple perfusion measurements at a second predetermined frequency corresponding to level M if the second Δ value exceeds the second threshold.

[0385] Embodiment 30. The method of embodiment 29, wherein the second threshold is the same as the first threshold.

[0386] Embodiment 31. The method of embodiment 29, wherein the second threshold is greater than the first threshold.

[0387] Embodiment 32. The method of embodiment 29, wherein the value of M is equal to N+1 but not more than 10.

[0388] Embodiment 33. The method of Embodiment 29, wherein the value of M is proportional to the amount by which the second delta value exceeds the second threshold.

[0389] Example 34. The method according to Example 29 further includes the following steps: determining whether the second Δ value is less than a third threshold value, if the second Δ value is less than the third threshold value and if the first intervention is not level 0, performing an (N-1) level intervention; and if the second Δ value is less than the third threshold value, performing multiple perfusion measurements at a predetermined frequency corresponding to the (N-1) level.

[0390] Embodiment 35. The method of embodiment 19, wherein the level 0 intervention is selected from the group consisting of providing good nutrition, a standard mattress, turning every 24 hours, and combinations thereof.

[0391] Embodiment 36. The method of Embodiment 19, wherein the first delta value exceeding the first threshold is calculated based on a portion of a first plurality of perfusion measurements taken at the patient's heel.

[0392] Example 37. The method of Example 36, wherein Level 1 intervention is providing the patient with a heel boot.

[0393] Example 38. The method of Example 36, wherein the Level 2 intervention is changing the patient's support surface.

[0394] Example 39. The method of Example 36, wherein the Level 3 intervention is application of a dressing to the back or side of the patient's heel.

[0395] Example 40. The method of Example 36, wherein the Level 4 intervention is changing the patient's bed linen to a low-friction bed linen.

[0396] Example 41. The method of Example 36, wherein the Level 5 intervention is providing a low-friction mattress surface for the patient's lower leg.

[0397] Example 42. The method of Example 36, wherein the Level 6 intervention is turning the patient at shorter intervals than currently provided.

[0398] Example 43. The method of Example 36, wherein the Level 7 intervention is applying skin cream to the patient's heel.

[0399] Example 44. The method of Example 36, wherein the Level 8 intervention is applying neuromuscular stimulation to the patient's heel.

[0400] Example 45. The method of Example 36, wherein the Level 9 intervention is applying a topical cream to the patient's heel to enhance perfusion.

[0401] Example 46. The method of Example 36, wherein the level 10 intervention is providing a silicone pad to the patient's calf.

[0402] Example 47. The method of Example 19, wherein the first delta value exceeding the first threshold is calculated based on a portion of the first plurality of perfusion measurements taken at the patient's sacrum.

[0403] Embodiment 48. The method of embodiment 47, wherein the Level 1 intervention is selected from the group consisting of: repositioning the patient with a wedge, keeping the patient's sacrum dry, and combinations thereof.

[0404] Embodiment 49. The method of embodiment 47, wherein the Level 2 intervention is changing the patient's mattress to a pressure-relieving mattress.

[0405] Embodiment 50. The method of embodiment 47, wherein the level 3 intervention is application of a dressing to the patient's sacrum.

[0406] Example 51. The method of Example 47, wherein the Level 4 intervention is changing the patient's mattress to a powered mattress.

[0407] Example 52. The method of Example 47, wherein the Level 5 intervention is applying skin cream to the patient's sacrum.

[0408] Example 53. The method of Example 47, wherein the Level 6 intervention is application of neuromuscular stimulation to the patient's sacrum.

[0409] Example 54. The method of Example 47, wherein the Level 7 intervention is applying a topical cream to the patient's sacrum to enhance perfusion.

[0410] Example 55. The method of Example 47, wherein the Level 8 intervention is providing a silicone pad under the patient's body.

[0411] Embodiment 56. The method of embodiment 19, wherein the level 0 predetermined frequency is once every 24 hours.

[0412] Embodiment 57. The method of Embodiment 19, wherein the Level 1 predetermined frequency is once every 10 hours.

[0413] Embodiment 58. The method of embodiment 19, wherein the Level 2 scheduled frequency is the beginning of each nursing shift.

[0414] Embodiment 59. The method of Embodiment 19, wherein the Level 3 predetermined frequency is once every 12 hours.

[0415] Embodiment 60. The method of Embodiment 19, wherein the Level 4 predetermined frequency is once every 8 hours.

[0416] Embodiment 61. The method of embodiment 19, wherein the level 5 predetermined frequency is once every 6 hours.

[0417] Embodiment 62. The method of embodiment 19, wherein the level 6 predetermined frequency is once every 4 hours.

[0418] Embodiment 63. The method of embodiment 19, wherein the level 7 predetermined frequency is once every 2 hours.

[0419] Embodiment 64. The method of embodiment 19, wherein the predetermined frequency of level 8 is once every hour.

[0420] Embodiment 65. The method of embodiment 19, wherein the level 9 predetermined frequency is once every 0.5 hours.

[0421] Example 66. A method for slowing the progression of skin and tissue damage in a patient in need thereof, the method comprising the following steps: identifying a level K intervention currently being received by the patient; performing multiple perfusion measurements in the patient; calculating a Δ value based on a portion of the multiple perfusion measurements; determining whether the Δ value exceeds a first threshold; if the Δ value does not exceed the first threshold, continuing to administer the current intervention; if the Δ value does not exceed the first threshold, continuing to administer multiple perfusion measurements at a predetermined frequency corresponding to the level K; if the Δ value exceeds the first threshold, administering a new level N intervention, where the value of N is greater than K; and if the Δ value exceeds the first threshold, performing multiple perfusion measurements at a predetermined frequency corresponding to the level N.

[0422] Embodiment 67. The method of embodiment 66, wherein the value of N is equal to K+1 but not more than 10.

[0423] Embodiment 68. The method of embodiment 66, wherein the value of N is proportional to the amount by which the Δ value exceeds the first threshold.

[0424] Example 69. The method according to Example 66 further includes the following steps: determining whether the Δ value is less than a second threshold; if the Δ value is less than the second threshold, applying an L-level intervention, where L has a non-negative value less than K; and if the Δ value is less than the second threshold, performing multiple perfusion measurements at a predetermined frequency corresponding to the L level.

[0425] Embodiment 70. The method of embodiment 69, wherein the value of L is equal to L-1.

[0426] Embodiment 71. The method of Embodiment 69, wherein the value of L is selected based on the amount by which the Δ value is less than the second threshold.

[0427] Embodiment 72. The method of embodiment 66, wherein the patient in need is a patient undergoing a change in care.

[0428] Embodiment 73. The method of embodiment 66, wherein the patient in need thereof is a patient experiencing changes in mobility.

[0429] Embodiment 74. The method of embodiment 66, wherein the patient in need thereof is a patient undergoing nutritional changes.

[0430] Embodiment 75. The method of embodiment 66, wherein the patient in need thereof is a patient experiencing changes in sensory perception.

[0431] Embodiment 76. The method of embodiment 66, wherein the patient in need thereof is a patient who develops an open ulcer.

[0432] Embodiment 77. The method of embodiment 66, wherein the patient in need thereof is a patient recovering from an open ulcer.

[0433] Example 78. The method of Example 66, wherein the patient in need thereof is a patient undergoing surgery.

[0434] Example 79. The method of Example 66, wherein the patient receives spinal analgesics during the surgery.

[0435] Embodiment 80. The method of embodiment 78, wherein the patient receives sacral analgesia during the surgery.

[0436] Example 81. The method of Example 78, wherein the surgery lasts for more than 4 hours.

[0437] Example 82. A method for selecting a wound treatment for a patient, the method comprising the steps of: assessing the patient's risk of tissue damage when the patient is admitted to a nursing facility, wherein the assessing step comprises: performing a first plurality of perfusion measurements in the patient; calculating a first Δ value based on a portion of the first plurality of perfusion measurements; determining whether the first Δ value exceeds a first threshold; if the first Δ value does not exceed the first threshold, applying a level 0 first intervention; and if the first Δ value exceeds the first threshold, applying a level N first intervention, wherein N is an integer and the value of N is 1 or greater.

[0438] Example 83. A method for stratifying patient groups in a nursing facility based on risk of wound development, the method comprising the following steps: performing multiple perfusion measurements in each of the patients; calculating a Δ value based on a portion of the multiple perfusion measurements for each of the patients; determining whether each Δ value exceeds any value in a set of thresholds corresponding to N levels of care and assigning a level of care to each patient; and then rearranging the patient groups based on the level of care assigned to each patient.

[0439] Example 84. A method for reducing the incidence of wound development in patients admitted to a nursing facility, the method comprising the following steps: assessing the patient's risk of tissue damage upon admission to the nursing facility, wherein the assessing step comprises: performing a first plurality of perfusion measurements in the patient; calculating a first Δ value based on a portion of the first plurality of perfusion measurements; determining whether the first Δ value exceeds a first threshold; if the first Δ value does not exceed the first threshold, applying a level 0 first intervention; and if the first Δ value exceeds the first threshold, applying a level N first intervention, wherein N is an integer and the value of N is 1 or greater.

[0440] Embodiment 85. The method of embodiment 84, wherein the incidence of wound development in patients in the care facility is reduced to 1 / 100.

[0441] Example 86. A method for identifying and treating a patient who needs to have skin cream applied to their heel, the method comprising the following steps: performing multiple perfusion measurements at the patient's heel; calculating a Δ value based on a portion of the multiple perfusion measurements; determining whether the Δ value exceeds a threshold corresponding to level N, where N is greater than or equal to 2; applying skin cream to the patient's heel if the Δ value exceeds the threshold; and performing multiple perfusion measurements every two hours if the Δ value exceeds the threshold.

[0442] Example 87. A method for identifying and treating a patient requiring neuromuscular stimulation to their heel, the method comprising the steps of: performing multiple perfusion measurements at the patient's heel; calculating a Δ value based on a portion of the multiple perfusion measurements; determining whether the Δ value exceeds a threshold corresponding to level N, where N is greater than or equal to 2; applying neuromuscular stimulation to the patient's heel if the Δ value exceeds the threshold; and performing multiple perfusion measurements every hour if the Δ value exceeds the threshold.

[0443] Example 88. A method for identifying and treating a patient who requires application of a topical cream to their heel, the method comprising the steps of: taking a plurality of perfusion measurements at the patient's heel; calculating a Δ value based on a portion of the plurality of perfusion measurements; determining whether the Δ value exceeds a threshold corresponding to level N, where N is greater than or equal to 2; applying a topical cream to the patient's heel if the Δ value exceeds the threshold; and taking a plurality of perfusion measurements every half hour if the Δ value exceeds the threshold.

[0444] Example 89. A method for identifying and treating a patient who needs to have skin cream applied to their sacrum, the method comprising the following steps: performing multiple perfusion measurements at the patient's sacrum; calculating a Δ value based on a portion of the multiple perfusion measurements; determining whether the Δ value exceeds a threshold corresponding to level N, where N is greater than or equal to 2; applying skin cream to the patient's sacrum if the Δ value exceeds the threshold; and performing multiple perfusion measurements every six hours if the Δ value exceeds the threshold.

[0445] Example 90. A method for identifying and treating a patient requiring neuromuscular stimulation to their sacrum, the method comprising the steps of: performing multiple perfusion measurements at the patient's sacrum; calculating a Δ value based on a portion of the multiple perfusion measurements; determining whether the Δ value exceeds a threshold corresponding to level N, where N is greater than or equal to 2; applying neuromuscular stimulation to the patient's sacrum if the Δ value exceeds the threshold; and performing multiple perfusion measurements every four hours if the Δ value exceeds the threshold.

[0446] Example 91. A method for identifying and treating a patient who requires application of a topical cream to their sacrum, the method comprising the steps of: taking a plurality of perfusion measurements at the patient's sacrum; calculating a delta value based on a portion of the plurality of perfusion measurements; determining whether the delta value exceeds a threshold corresponding to a level N, where N is greater than or equal to 2; applying a topical cream to the patient's sacrum if the delta value exceeds the threshold; and taking a plurality of perfusion measurements every two hours if the delta value exceeds the threshold.

[0447] Embodiment 92. A device for identifying damaged tissue, the device comprising: a transmitter and two receivers, wherein each of the transmitter and the two receivers is configured to be placed against a patient's skin; a processor electronically coupled to the receivers and configured to receive information from the receivers and convert the information into a perfusion value; and a non-transitory computer-readable medium electronically coupled to the processor and comprising instructions stored thereon, which, when executed on the processor, perform the following steps: determining a difference between a first perfusion value corresponding to reflected light measured by the first receiver at a first location on the patient's skin and a second perfusion value corresponding to reflected light measured by the second receiver at a second location on the patient's skin, wherein the second location is bilaterally symmetrical relative to the first location.

[0448] Example 93. The apparatus of Example 92, wherein the difference being greater than a predetermined threshold indicates damaged tissue at one of the first and second locations.

[0449] Example 94. The device according to Example 93 further includes: a substrate configured to be placed at a known position on the patient's skin, and the first and second receivers are arranged on the substrate so that when the substrate is placed on the known position on the patient's skin, the first and second receivers are positioned at bilaterally symmetrical positions on the patient's skin.

[0450] Embodiment 95. The apparatus of Embodiment 92, further comprising a gap between the first and second receivers.

[0451] Embodiment 96. A device for identifying damaged tissue, the device comprising: a substrate configured to be placed against a surface of a patient's skin; a plurality of emitters disposed at a corresponding plurality of locations on the substrate; a plurality of receivers disposed at a corresponding plurality of locations on the substrate, wherein each receiver is configured to measure reflected light and provide information about blood perfusion; a processor electronically coupled to the receivers and configured to receive information about the reflected light and convert the plurality of reflected light measurements into a corresponding plurality of perfusion values; and a non-transitory computer-readable medium electronically coupled to the processor and comprising instructions stored thereon that, when executed on the processor, perform the following steps: identifying a first receiver and a second receiver located at first and second positions that are bilaterally symmetrical relative to the patient's skin from the plurality of values; and comparing a first perfusion value associated with the first receiver with a second perfusion value associated with the second receiver.

[0452] Example 97. The apparatus of Example 96, wherein the instructions further comprise the steps of: determining a difference between the first and second perfusion values; and providing an indication of tissue damage at one of the first and second locations if the difference is greater than a predetermined threshold.

[0453] Example 98. An apparatus according to Example 96, wherein the instructions further include the steps of: determining a difference between the first and second perfusion values; determining which of the first and second perfusion values ​​is greater than the other; and if the difference is greater than a predetermined threshold, providing an indication of tissue damage at a location associated with the larger perfusion value.

[0454] Embodiment 99. A device for identifying damaged tissue, the device comprising: a device body; a transmitter; a first receiver and a second receiver, wherein the two receivers are arranged on the device body to allow the first receiver to be positioned at a first position on the patient's skin and the second receiver to be simultaneously positioned at a second position that is bilaterally symmetrical relative to the first position; a circuit, electronically coupled to each of the two receivers and configured to measure reflected light detected by each of the two receivers; a processor, electronically coupled to the circuit and configured to receive a first reflected light measurement from the first position and a second reflected light measurement from the second position, and convert the first reflected light measurement into a first perfusion value and convert the second reflected light measurement into a second perfusion value; and a non-temporary computer-readable medium, electronically coupled to the processor and containing instructions that, when executed on the processor, perform the step of determining the difference between the first perfusion value and the second perfusion value.

[0455] Embodiment 100. The apparatus of embodiment 99, wherein each of the two receivers is disposed at opposite ends of the apparatus body while being aligned on a common plane.

[0456] Embodiment 101. The apparatus of Embodiment 99, wherein the apparatus body is rigid and holds the two receivers at a fixed separation distance and in a fixed orientation from one another.

[0457] Embodiment 102. The device of Embodiment 99, wherein the device body is flexible and allows the two receivers to be oriented at an angle to each other.

[0458] Embodiment 103. The device of embodiment 102, wherein the device body comprises a hinge.

[0459] Embodiment 104. The apparatus of Embodiment 99, wherein the first reflected light measurement and the second reflected light measurement are measured simultaneously.

[0460] Embodiment 105 The apparatus of Embodiment 104, wherein the apparatus further comprises a contact sensor located near one of the two receivers, and wherein the simultaneous measurement is triggered by actuation of the contact sensor.

[0461] Embodiment 106 The device of Embodiment 105, wherein the contact sensor is a pressure sensor or an optical sensor.

[0462] Embodiment 107. The apparatus of Embodiment 99, wherein the instructions further comprise the step of providing an indication of tissue damage at one of the first and second locations if the difference is greater than a predetermined threshold.

[0463] Example 108. An apparatus according to Example 99, wherein the instructions further comprise the steps of: determining the larger of the first and second perfusion values; and if the difference exceeds a predetermined threshold, providing an indication of tissue damage at the location associated with the larger perfusion value.

[0464] Embodiment 109. A method for identifying damaged tissue, the method comprising: obtaining a first perfusion value from a first location on a patient's skin; obtaining a second perfusion value from a second location that is bilaterally symmetric relative to the first location; and determining a difference between the first perfusion value and the second perfusion value.

[0465] Embodiment 110 The method of Embodiment 109, further comprising providing an indication of tissue damage at one of the first and second locations if the difference is greater than a predetermined threshold.

[0466] Example 111. The apparatus of Example 109, further comprising: determining the greater of the first and second perfusion values; and providing an indication of tissue damage at the location associated with the greater perfusion value if the difference exceeds a predetermined threshold.

[0467] Example 112. A method for detecting tissue damage before it is visible on a patient's skin, comprising: measuring multiple perfusion values ​​at a single location at incremental times; calculating a slope between the most recent perfusion value and the immediately previous perfusion value; comparing this slope to a threshold; and determining that tissue damage is present if the slope exceeds the threshold.

[0468] Example 113. A method for detecting tissue damage before it is visible on a patient's skin, comprising: measuring multiple perfusion values ​​at multiple locations at incremental times; calculating a Δ value for each of the multiple perfusion values; calculating a slope between the most recent Δ value and the immediately previous Δ value; comparing this slope to a threshold; and determining that tissue damage is present if the slope exceeds the threshold.

[0469] Example 114. A method for detecting tissue damage before the damage is visible on a patient's skin, the method comprising: measuring multiple perfusion values ​​at a single location at each of multiple incremental times; calculating a perfusion Δ value for each incremental time; fitting a curve to a predetermined number of nearest perfusion Δ values; calculating the curvature of the fitted curve; comparing this curvature to a threshold; and determining that tissue damage is present if the curvature exceeds the threshold.

[0470] Although the present invention has been described with reference to specific aspects, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the present invention. In addition, various modifications may be made to the specific circumstances or materials taught by the present invention without departing from the scope of the present invention. Therefore, it is not intended that the present invention be limited to the specific aspects disclosed, but rather that the present invention encompasses all aspects coming within the scope and spirit of the appended claims.

Claims

1. An apparatus for evaluating blood perfusion in tissue beneath the skin of a patient, comprising: an emitter configured to emit light of a first wavelength and a second wavelength when activated, a first receiver configured to measure a first intensity of the received light at the first wavelength and a second intensity of the received light at the second wavelength and to provide a first signal including information about the first and second intensities of the received light, wherein the first receiver is spaced apart from the transmitter by a first distance, the first distance being selected such that light emitted by the transmitter and received by the first receiver is reflected from a first depth beneath the patient's skin, a second receiver configured to measure a third intensity of the received light of the first wavelength, measure a fourth intensity of the received light of the second wavelength, and provide a second signal including information about the third and fourth intensities of the received light, wherein the second receiver is spaced apart from the transmitter by a second distance, the second distance being selected such that light emitted by the transmitter and received by the second receiver is reflected from a second depth beneath the patient's skin, a substrate coupled to the transmitter and the first and second receivers and configured such that the transmitter and the first receiver can be placed in contact with the patient's skin simultaneously, and a processor coupled to the first receiver and the second receiver and configured to: receiving the first signal, determining a first sum value of said first and second intensities of the received light, determining a perfusion level of the tissue based on the first sum value, receiving the second signal, determining a fifth intensity of the received light by subtracting the third intensity from the first intensity, determining a sixth intensity of the received light by subtracting the fourth intensity from the second intensity, determining a second sum value of the fifth and sixth intensities, and Based on the second summation value, a perfusion level of the tissue between the first depth and the second depth is determined.

2. The apparatus of claim 1, wherein the first wavelength is associated with a peak absorption wavelength of oxygenated hemoglobin and the second wavelength is associated with a peak absorption wavelength of deoxygenated hemoglobin.

3. The apparatus of claim 1, wherein the emitter comprises a first source that emits light at the first wavelength and a second source that emits light at the second wavelength. The device of claim 3 , wherein the first source and the second source can be activated independently. 5 . The apparatus of claim 1 , wherein the receiver comprises a first detector that senses light at the first wavelength and a second detector that senses light at the second wavelength.

6. The apparatus according to claim 5, wherein: The processor is individually coupled to each of the first detector and the second detector, and The first signal comprises separate signals from the first and second detectors.

7. The apparatus of claim 1 , wherein: the processor being coupled to the transmitter, The emitter is configured to emit light upon receiving a strobe pulse, The processor is configured to provide the strobe pulse to the transmitter and the first receiver, The first receiver is further configured to measure a first time period between receiving the strobe pulse and receiving light from the transmitter, and The first signal includes information about the first time period.

8. The device of claim 1, further comprising a memory coupled to the processor, wherein the processor is configured to store a series of sum values ​​associated with sequential activations of the transmitters in the memory. 9 . The apparatus of claim 8 , wherein the processor is further configured to determine a range between a minimum sum value and a maximum sum value in the series of sum values.

10. The apparatus of claim 8, wherein the processor is further configured to determine a percentage value for each sum value relative to a maximum sum value in the series of sum values.

11. The device of claim 1 , further comprising an accelerometer configured to provide a third signal comprising information about acceleration of the device in three spatial dimensions, wherein: The processor is coupled to the accelerometer and is configured to receive the third signal, and The processor is further configured to determine a spatial location of the transmitter when the transmitter is activated.

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