Perfusion and oxygenation measurement

Abstract

The present disclosure provides methods and devices for assessing blood flow in damaged or healed tissue. The disclosure also provides methods of identifying a patient at risk of developing a pressure sore or at risk of developing a pressure sore and treating the patient with an anatomical specific clinical intervention selected based on perfusion or blood oxygenation values, or a combination thereof. The present disclosure also provides methods of stratifying groups of patients based on the risk of wound development, and methods of reducing the incidence of tissue damage in a care institution. The present disclosure also provides methods for analyzing the tendency of perfusion or oxygenation measurements to detect tissue damage before it is visible, and methods for comparing bilateral symmetric perfusion values to identify damaged tissue.

Description

[0001] This application is a divisional application of patent application 201980047387.7, which has entered the Chinese national phase of PCT application with international application number PCT / US2019 / 041861 and international application date July 15, 2019.

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] 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

[0004] 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 sore 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 it is visible on the patient's skin. Background Art

[0005] The skin is the largest organ of the human body. It is easily exposed to a wide range of different injuries and injuries. When the skin and its surrounding tissues are unable to redistribute external pressure and mechanical forces, skin damage and injury may occur and ulcers may form. Pressure ulcers may result from prolonged continuous exposure to even moderate pressure, such as the pressure produced by the weight of a supine patient on the skin surface of their buttocks. In the presence of other insults, such as neuropathy and weakening of surrounding tissues that can be caused by diabetes, even regular exposure to moderate levels of pressure and stress may result in ulcers, such as foot ulcers.

[0006] In the United States, approximately 2.5 million people develop pressure ulcers each year, and a similar number 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 caused by pressure ulcers.

[0007] Most pressure ulcers develop over bony prominences where there is less compressed tissue and where there is a change in pressure gradient within the vascular network. Pressure ulcers are classified into one of six stages, ranging from: skin remains intact but redness may appear over the bony prominence – the earliest stage currently recognised (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 (undefined stage). In major economies, the goal of policymakers and care providers is to detect pressure ulcers before the skin breaks down and treat them to avoid progression to later stages. Most pressure ulcers are preventable, and if pressure ulcers are identified before stage 1, deterioration of the underlying tissue can be stopped.

[0008] It is desirable for patients and society to detect tissue damage before the skin breaks down and to intervene with appropriate treatment to avoid further deterioration of the underlying tissue. The average cost of treating pressure-induced injuries at the earliest visible signs (stage 1 ulcers) is only $2,000, but this average cost rises to $129,000 when the ulcer is deep enough to expose muscle or bone (stage 4 ulcers). See, for example, Brem, H. et al. (2010). High Cost of Stave IV Pressure Ulcers. Am. J. Surg. Oct; 200(4): 473-477. Currently, patients typically receive comprehensive prevention of pressure ulcers, meaning that prevention is not targeted to any specific anatomical site. Only after the pressure ulcer has developed to a degree that can be determined by visual evaluation do patients receive targeted local ulcer treatments. 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.

[0009] Certain types of surgery may also result in skin damage and injury, for example, reconstructive surgery involving skin flaps will sever blood vessels in or around the surgical site. The healing of damaged or separated tissue depends on the reestablishment of adequate blood flow throughout the damaged area. It is difficult to determine by visual inspection whether an area of ​​tissue is healing, i.e., 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.

[0010] Fluorescein has been used clinically for more than 40 years to evaluate flap vascularity. Fluorescein fluoresces yellow-green (510-600nm) when excited by ultraviolet (UV). Tissue with good blood flow will appear bright yellow, while areas without blood flow will appear dark blue. Fluorescein is usually given as a bolus injection of 500-1000mg. After waiting 20-30 minutes, the tissue can be evaluated with a UV lamp. This method takes 30 minutes to administer and can only be applied once every 8 hours.

[0011] Near infrared spectroscopy (NIRS) is used to determine the ratio of oxygenated to deoxygenated hemoglobin by illuminating specific wavelengths of light (760nm and 830nm) and measuring the amount of reflected or transmitted light. Currently, there are devices available that provide images showing local oxygenation at the surface of the skin. Although this is important clinical information, it does not show the actual perfusion level of the tissue, nor can it distinguish the condition of the surface tissue from that of deeper tissue layers.

[0012] Currently, there are two types of Doppler instruments in clinical use. The first is ultrasonic Doppler, which senses the phase shift of reflected sound to measure the velocity of moving elements, which are assumed to be red blood cells in the blood vessels. The second is laser Doppler, which senses the phase shift of reflected light to detect the velocity of red blood cells. These methods are limited to evaluating blood flow in larger blood vessels and cannot evaluate perfusion in smaller arteries and capillaries. Summary of the invention

[0013] A systematic approach is provided for identifying the risk of developing a pressure ulcer prior to visible skin damage using non-invasive objective measurements and then administering personalized interventions at specific anatomical structures. A systematic approach is also provided for identifying the risk of developing a pressure ulcer prior to visible skin damage using non-invasive objective measurements and then administering personalized interventions at specific anatomical structures. Methods for monitoring wound healing progress and consistency of intervention compliance are further provided.

[0014] 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: 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 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 at the same time; and a processor coupled to the first receiver. The processor is 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.

[0015] In one aspect, the present disclosure provides and includes a method for evaluating blood perfusion in tissue beneath the skin of a patient. The method includes the steps of emitting light toward the patient's skin at a first location on the patient's skin. The light has a first wavelength and a second wavelength. The method also includes the steps of 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.

[0016] 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.

[0017] In one aspect, the present disclosure provides and includes a method of reducing the incidence of wound development in a patient admitted to a care facility, the method comprising the steps of: assessing a patient's risk of tissue damage upon admission to the care facility, wherein the assessing step comprises: performing a first plurality of perfusion measurements at one or more body locations of the patient at risk of 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; applying a level 0 first intervention if the first delta value does not exceed the first threshold; and applying 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 of wound development are selected from the group consisting of: the patient's sternum, sacrum, heel, scapula, elbow, ear, and other bony prominences. In one aspect, the one or more body locations at risk of wound development include one or more anatomical sites that are in long-term contact with a medical device and are selected from the group consisting of: cheeks, nose, chest, stomach, and lower abdominal sites.

[0018] In one aspect, the present disclosure provides and includes a method for reducing the incidence of wound development in a patient admitted to a care facility, the method comprising the steps of: assessing the patient's risk of tissue damage upon admission to the care facility, wherein the assessing step comprises: taking a first plurality of SpO2 measurements at one or more body locations of the patient at risk of 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; 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 of wound development are selected from the group consisting of: the patient's sternum, sacrum, heel, scapula, elbow, ear, and other bony prominences of the skin and flesh. In one aspect, the one or more body locations at risk of wound development include one or more anatomical sites that are in long-term contact with a medical device and are selected from the group consisting of: cheeks, nose, chest, stomach, and lower abdominal areas.

[0019] 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 a plurality of perfusion measurements at one or more selected body locations for monitoring of 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 skin and flesh. In one aspect, the one or more body locations for monitoring include one or more anatomical sites that are in long-term contact with a medical device and are selected from the group consisting of: cheeks, nose, chest, stomach, and lower abdominal sites.

[0020] 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 at one or more selected body locations for monitoring of each of the patients; determining whether each of the multiple SpO2 measurements is below any value in a set of thresholds corresponding to N care levels and assigning a care level to each of the patients; and rearranging the patient groups according to the care level 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 skin and flesh. In one aspect, the one or more body locations for monitoring include one or more anatomical sites that are in long-term contact with a medical device and are selected from the group consisting of: cheeks, nose, chest, stomach, and lower abdominal areas.

[0021] In one aspect, the present disclosure provides and includes a method of 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 anatomical structure specific intervention is provided to the patient. In one aspect, an increasingly intensive therapeutic intervention is provided to the patient based on changes in the perfusion measurements. In one aspect, a less intensive therapeutic intervention is given to the patient based on changes in the perfusion measurements.

[0022] In one aspect, the present disclosure provides and includes 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 given to the patient based on changes in the SpO2 measurements.

[0023] 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 including a plurality of risk categories, wherein the assignment is based in part on the initial perfusion measurement at the body location.

[0024] 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 including a plurality of risk categories, wherein the assignment is based in part on the initial SpO2 measurement at the body location.

[0025] In one aspect, the present disclosure provides and includes a method for managing patient care, the method comprising the steps of: upon admission to a nursing facility, performing an initial assessment of the patient and taking an initial set of perfusion measurements for all body locations selected for monitoring; calculating an initial Δ value for each body location selected for monitoring; determining that the patient's measurements are abnormal if any initial Δ value is greater than or equal to a first threshold, and setting an intervention level to N=1; performing N levels of intervention for each body location with a Δ 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 Δ 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 skin and flesh. In one aspect, the one or more body locations for monitoring include one or more anatomical sites that are in long-term contact with a medical device and are selected from the group consisting of: cheeks, nose, chest, stomach, and lower abdominal areas.

[0026] In one aspect, the present disclosure provides and includes a method for managing patient care, the method comprising the following steps: upon admission to a nursing facility, performing an initial assessment of the patient and taking a set of initial 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 to 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.

[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 following steps: 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 applied; 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; continuing to apply 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 does not exceed the second threshold; applying a second intervention of level M if the second delta 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 delta value exceeds the second threshold. In an even further aspect, the present disclosure provides and includes: determining whether the second delta value is less than a third threshold; applying a level (N-1) intervention if the second delta value is less than the third threshold and if the first intervention is not level 0; and performing a plurality of perfusion measurements at a predetermined frequency corresponding to level (N-1) if the second delta value is less than the third threshold.

[0028] 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 following steps: assessing the patient's risk of tissue damage upon admission to a nursing facility, wherein the assessing step comprises: performing 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 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 apply 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 does not exceed the second threshold; applying a second intervention of level M if the time delta value is a decrease that exceeds the second threshold, wherein M is an integer and M is greater than N; and taking a plurality of SpO2 measurements at a second predetermined frequency corresponding to level M if the time delta value is a decrease that exceeds the second threshold. In a further aspect, the present disclosure provides and includes: determining whether the time delta value is an increase that exceeds a third threshold; applying a level (N-1) of intervention if the time delta value is an increase that exceeds the third threshold and if the first intervention is not level 0; and taking a plurality of SpO2 measurements at a predetermined frequency corresponding to level (N-1) if the time delta value is an increase that exceeds the third threshold.

[0029] In one aspect, the present disclosure provides and includes a method of slowing progression of skin and tissue damage in a patient in need thereof, the method comprising the steps of: identifying a level K current intervention that the patient is receiving; 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 apply the current intervention threshold; if the delta value does not exceed the first threshold, continuing to take a plurality of perfusion measurements at a predetermined frequency corresponding to the level K; if the delta value exceeds the first threshold, applying a level N new intervention, where the value of N is greater than K; and if the delta value exceeds the first threshold, taking 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, applying 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, taking a plurality of perfusion measurements at a predetermined frequency corresponding to the level L.

[0030] 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; performing a plurality of SpO2 measurements in the patient; determining whether any of the plurality of SpO2 measurements exceeds a first threshold; continuing to apply the current intervention if the plurality of SpO2 measurements are within a threshold range corresponding to the level K; performing a plurality of perfusion measurements at a predetermined frequency corresponding to the level K if the Δ value is within a threshold range corresponding to the level K; applying a level N new intervention, where the value of N is greater than K, if any of the plurality of SpO2 measurements is below the first threshold range; and performing a plurality of perfusion measurements at a predetermined frequency corresponding to the level N 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, applying 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, performing multiple SpO2 measurements at a predetermined frequency corresponding to level L.

[0031] In one aspect, the present disclosure provides and includes a method for identifying and treating a patient who needs to apply a skin cream to his or her 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; if the Δ value exceeds the threshold, applying a skin cream to the patient's heel; and if the Δ value exceeds the threshold, performing multiple perfusion measurements every two hours.

[0032] In one aspect, the present disclosure provides and includes a method for identifying and treating a patient who needs to apply a skin cream to his or her heels, 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 skin cream 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.

[0033] In one aspect, the present disclosure provides and includes a method for identifying and treating a patient who requires neuromuscular stimulation to be applied to his or her 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; if the Δ value exceeds the threshold, applying neuromuscular stimulation to the patient's heel; and if the Δ value exceeds the threshold, performing multiple perfusion measurements every hour.

[0034] In one aspect, the present disclosure provides and includes a method for identifying and treating a patient who needs neuromuscular stimulation applied to his 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; if any of the multiple SpO2 measurements is below the threshold, applying neuromuscular stimulation to the patient's heel; and if any of the multiple SpO2 measurements is below the threshold, taking multiple SpO2 measurements every hour.

[0035] In one aspect, the present disclosure provides and includes a method of identifying and treating a patient who needs to have a topical cream applied to his or her 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 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.

[0036] In one aspect, the present disclosure provides and includes a method of identifying and treating a patient who needs to have a topical cream applied to his or her 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.

[0037] In one aspect, the present disclosure provides and includes a method for identifying and treating a patient who needs a heel boot applied to his 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; if the Δ value exceeds the threshold, applying a heel boot to the patient's heel; and if the Δ value exceeds the threshold, taking multiple perfusion measurements every half hour.

[0038] In one aspect, the present disclosure provides and includes a method for identifying and treating a patient who needs a heel boot applied to his 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 heel boot to the patient's heel if any of the multiple SpO2 measurements is below the threshold; and taking multiple SpO2 measurements every half hour if any of the multiple SpO2 measurements is below 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 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; if the Δ value exceeds the threshold, applying skin cream to the patient's sacrum; and if the Δ value exceeds the threshold, performing multiple perfusion measurements every six hours.

[0040] 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.

[0041] In one aspect, the present disclosure provides and includes a method for identifying and treating a patient who requires neuromuscular stimulation to be applied to his or her 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; if the Δ value exceeds the threshold, applying neuromuscular stimulation to the patient's sacrum; and if the Δ value exceeds the threshold, performing multiple perfusion measurements every four hours.

[0042] In one aspect, the present disclosure provides and includes a method for identifying and treating a patient in need of neuromuscular stimulation applied to his or her 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 neuromuscular stimulation to the patient's sacrum if any of the multiple SpO2 measurements is below the threshold; and taking multiple SpO2 measurements every four hours if any of the multiple SpO2 measurements is below the threshold.

[0043] 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 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.

[0044] 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 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.

[0045] In one aspect, the present disclosure provides and includes a method of identifying and treating a patient in need of therapeutic ultrasound being applied thereto, 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 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: flesh tissue over the patient's sternum, sacrum, heel, scapula, elbow, ear, and other bony prominences.

[0046] In one aspect, the present disclosure provides and includes a method of identifying and treating a patient in need of applying therapeutic ultrasound thereto, 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 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: flesh tissue over the patient's sternum, sacrum, heel, scapula, elbow, ear, and other bony prominences.

[0047] In one aspect, the present disclosure provides and includes a method of identifying and treating a patient in need of shock wave therapy being applied thereto, 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 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: flesh tissue over the patient's sternum, sacrum, heel, scapula, elbow, ear, and other bony prominences. In one aspect, the shock wave therapy is provided by electromagnetic pulses or pressurized air.

[0048] In one aspect, the present disclosure provides and includes a method of identifying and treating a patient in need of shock wave therapy being applied thereto, 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 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: flesh tissue over the patient's sternum, sacrum, heel, scapula, elbow, ear, and other bony prominences. In one aspect, the shock wave therapy is provided by electromagnetic pulses or pressurized air.

[0049] In one aspect, the present disclosure provides and includes a method of identifying and treating a patient who needs a 30 degree wedge applied thereto, 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.

[0050] In one aspect, the present disclosure provides and includes a method of identifying and treating a patient who needs to have a 30 degree wedge applied thereto, 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.

[0051] In one aspect, the present disclosure provides and includes a method of identifying and treating a patient who needs to have a composite dressing applied thereto, 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.

[0052] In one aspect, the present disclosure provides and includes a method of identifying and treating a patient who needs to have a composite dressing applied thereto, 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.

[0053] In one aspect, the present disclosure provides and includes a method of 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: flesh tissue over the patient's sternum, sacrum, heel, scapula, elbow, ear, and other bony prominences.

[0054] In one aspect, the present disclosure provides and includes a method of identifying and treating a patient who needs to have a hybrid mattress applied thereto, 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: flesh tissue over the patient's sternum, sacrum, heel, scapula, elbow, ear, and other bony prominences.

[0055] In one aspect, the present disclosure provides and includes a method of 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: flesh tissue over the patient's sternum, sacrum, heel, scapula, elbow, ear, and other bony prominences.

[0056] In one aspect, the present disclosure provides and includes a method of identifying and treating a patient who needs to be provided with 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 tissue over the patient's sternum, sacrum, heel, scapula, elbow, ear, and other bony prominences.

[0057] 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, which, 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.

[0058] In one aspect, the present disclosure provides an apparatus for identifying damaged tissue, the apparatus comprising: a substrate configured to be placed against a patient's skin surface; 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.

[0059] 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, which, when executed on the processor, perform the step of determining the difference between the first perfusion value and the second perfusion value.

[0060] In one aspect, the present disclosure provides a method for identifying damaged tissue, the method comprising: obtaining a first perfusion value from a first position on a patient's skin; obtaining a second perfusion value from a second position that is bilaterally symmetric relative to the first position; and determining a difference between the first perfusion value and the second perfusion value.

[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 a single location at incremental times; calculating the 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.

[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 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.

[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, 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.

[0064] 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 multiple 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.

[0065] 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 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 determining that tissue damage is present if the slope exceeds the threshold.

[0066] 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 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 this derivative to a threshold; and determining that tissue damage is present if the derivative exceeds the threshold.

[0067] 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 SpO2 values ​​at a single location at each of multiple 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 that tissue damage is present if the curvature exceeds the threshold. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] 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 are used for illustrative discussion of aspects of the present disclosure. In this regard, considering the specification and drawings individually and together, it will be readily apparent to those skilled in the art how aspects of the present disclosure may be practiced.

[0069] Figure 1 The tissue surrounding the burn is depicted.

[0070] Figure 2A and 2B Depicted is a flap created as part of breast reconstruction surgery.

[0071] Figure 3 is a representative plot of the absorption spectra of oxygenated and deoxygenated hemoglobin.

[0072] Figure 4 Depicted is a block diagram of an example perfusion measurement device according to the present disclosure.

[0073] Figure 5 Depicted are exemplary configurations of perfusion measurement devices according to the present disclosure.

[0074] Figure 6 A cross section of tissue is depicted showing how emitted light is reflected by the tissue in accordance with the present disclosure.

[0075] Figure 7 Transmitted and detected signals are depicted according to an example system of the present disclosure.

[0076] Figure 8 Depicted is the path of reflected light with a wide angle source in accordance with the present disclosure.

[0077] Fig. 9 Depicts a device similar to Figure 8 The transmitted signal and detected signal of the system.

[0078] Fig. 10A and 10B Depicted are detected signals of light reflected from oxygenated and deoxygenated hemoglobin in accordance with the present disclosure.

[0079] Fig.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.

[0080] Fig. 11C According to the present disclosure Fig.11A and 11B A graph of the comparison points of the curve.

[0081] Fig.11D Depicts an example wound and Fig. 11C An exemplary diagram of the measurement lines of a diagram.

[0082] Fig.11E Depicted is an example graph of perfusion sum values ​​taken across another wound in accordance with the present disclosure.

[0083] Fig. 12A , 12B , 12C and 12D depict examples of the disclosed device according to the present disclosure.

[0084] Fig.13 is a flow chart of an exemplary method of perfusion measurement according to the present disclosure.

[0085] Fig.14 An example of an overall process for selecting a 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 discharge of the patient.

[0086] Fig.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.

[0087] Fig.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.

[0088] Fig.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.

[0089] Fig.18A and 18Bis an example of a method of mapping a tissue injury site according to the present disclosure.

[0090] Fig.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.

[0091] Fig.19B is an example of a current enhanced treatment decision pathway currently being implemented in some healthcare settings for the prevention of pressure ulcers.

[0092] Fig. 20 is an example flow chart according to the present disclosure that illustrates how a device for evaluating blood perfusion in tissue beneath a patient's skin may be used in a standalone procedure to prevent pressure sores.

[0093] Fig.21 is an example flow chart according to the present disclosure, which shows how an apparatus for evaluating blood perfusion in tissue beneath the skin of a patient can be used as an aid to further improve Fig.19B Enhanced treatment decision-making pathways.

[0094] Fig.22A An example of a pair of bilaterally symmetrical locations on the sacral region according to the present disclosure is provided.

[0095] Fig. 22B An example of a pair of bilaterally symmetrical locations on the soles of both feet according to the present disclosure is provided.

[0096] Fig. 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.

[0097] Fig.23A Shown are locations on the left and right feet for perfusion measurements in accordance with the present disclosure.

[0098] Fig. 23B is a graph of perfusion values ​​associated with known relative positions for identifying bilaterally symmetric locations in accordance with the present disclosure.

[0099] Fig.24 An integrated system for measuring, evaluating, storing and transferring perfusion values ​​according to the present disclosure is depicted.

[0100] Fig.25 Depicted are perfusion values ​​over time for patients at risk for developing pressure ulcers in accordance with the present disclosure.

[0101] Fig.26 Depicted are perfusion delta values ​​over time for patients who developed pressure ulcers in accordance with the present disclosure.

[0102] Fig. 27Depicted are illustrative perfusion and delta values ​​over time for a patient who developed a pressure ulcer in accordance with the present disclosure.

[0103] Fig.28 Depicted are example perfusion delta values ​​over time for a patient who developed a pressure ulcer on the heel in accordance with the present disclosure.

[0104] Fig.29A , 29B , 29C and 29D show various pressure points at different locations on the patient's body. DETAILED DESCRIPTION

[0105] 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, according to 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, known structures, interfaces, and processes are not shown in detail to avoid unnecessarily obscuring 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 exhaustively indicating all permutations, combinations, and variations thereof.

[0106] 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 the present 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.

[0107] All publications, patent applications, patents and other references cited herein are incorporated herein by reference in their entirety for teachings relevant to the sentences and / or paragraphs in which the references appear. References to the techniques employed herein are intended to refer to techniques commonly understood in the art, including variations of those techniques or substitutions of equivalent techniques that are obvious to those skilled in the art.

[0108] 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.

[0109] 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, the 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 sequences, otherwise without departing from the scope of the present disclosure, the order and / or purposes of specific steps and / or actions can be modified.

[0110] 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.

[0111] 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").

[0112] 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.

[0113] 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."

[0114] As used herein, the term "exemplary" is used to mean used 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 meant to exclude equivalent structures and techniques known to those of ordinary skill in the art. On the contrary, the use of the word exemplary is intended to present concepts in a concrete way, and the disclosed subject matter is not limited by such examples.

[0115] As used herein, the term "patient" includes both human and animal subjects.

[0116] As used herein, the term "skin" refers to the surface of a patient's body.

[0117] 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 a patient's body.

[0118] 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 be caused by a surgical procedure. A wound may be a burn wound. In one aspect, the wound is a pressure sore. In a further aspect, a 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.

[0119] As used herein, the term "increment" refers to the calculated difference between two values, which are derived from measurements obtained from a subject at about the same time. On the one hand, each value is the summed value calculated from measurements obtained at about the same time. On the one hand, 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.

[0120] As used herein, the term "time increment" refers to the calculated difference between two values, which are derived from measurements obtained from a subject at different times. On the one hand, each value is the average value calculated based on measurements obtained at about the same time. On the one hand, each value is the sum value calculated based on measurements obtained at about the same time. On the one hand, when the measurements are spaced apart for 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 about the same time.

[0121] As used herein, the variables "K," "L," "M," and "N" are non-negative integers.

[0122] 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 made.

[0123] As used herein, a "system" may be a collection of devices that communicate with each other by wire or wireless communication.

[0124] As used herein, "bilaterally symmetrical" refers to a pair of locations that are approximately equidistant from a line of symmetry.

[0125] 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.

[0126] As used herein, the term "light" refers to electromagnetic energy having a wavelength in the range of 1 picometer to 1 meter. On the one hand, this range is 1 nanometer to 1 millimeter, covering "ultraviolet", "visible" and "infrared" light. On the one hand, this range is 10-390 nanometers, which is generally considered to be "ultraviolet" light. On the one hand, this range is 390-700 nanometers, which is generally considered to be "visible" light. On the one hand, this range is 700 nanometers to 1 millimeter, which is generally considered to be "infrared" radiation. On the one hand, this range is 700-900 nanometers, which is generally considered to be "near infrared" radiation. On the one hand, this light can be a narrow wavelength band around a specific wavelength. On the one hand, the specific wavelength is 760 and / or 830 nanometers.

[0127] In this document, identifying light with a specific wavelength is synonymous with identifying light with a specific frequency because wavelength and frequency of light are uniquely related. Reference to the frequency of light is considered equivalent to and interchangeable with reference to the wavelength of the same light.

[0128] 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 activities can be interchanged. "Method" is considered equivalent to "process" and can be interchanged therewith. In some embodiments, one or more disclosed steps are omitted.

[0129] Perfusion and oxygenation measurements

[0130] Figure 1 Tissue surrounding a burn 102 of patient tissue 100 is depicted. Tissue 100 has a surface epidermis layer 110, a dermis layer 120, and a subcutaneous layer 130. Blood vessels 180 in layer 130 are connected to arterioles 182 that penetrate layers 120 and 110.

[0131] Burn 102 has a central region 150 which is a "necrotic zone" which is primarily dead tissue with a low water content. Surrounding region 150 is a region 160 called a "stasis zone" which is tissue characterized by decreased tissue perfusion. The tissue in region 160 is potentially salvageable and is of particular interest to clinicians because this is the area of ​​focus in treating burns. The next region 170 is a hyperemic zone where tissue perfusion is increased due to vasodilation caused by the local production of inflammatory mediators in region 170.

[0132] Figure 2A and 2B Depicted is a skin flap 240 created as part of a breast reconstruction procedure. In this example, a portion of skin 210 is removed from the back above the latissimus dorsi muscle 220, as shown in FIG. Figure 2A Skin 210 is placed at position 240 to provide an additional surface to cover implant 230, such as Figure 2B shown. Figure 2B Position 222 in the diagram indicates the location from which flap 210 was removed.

[0133] Figure 3 3 is a representative graph 300 of the absorption spectra of oxygenated hemoglobin 310 and deoxygenated hemoglobin 312. Oxygenation curve 310 has a local peak 320 at 760 nanometers, at which wavelength a difference is created between the local maxima of curve 310 and curve 312. 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 at wavelengths in the range of 760-830 nanometers can generally be used.

[0134] 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.

[0135] 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.

[0136] In one aspect, the transmitter 420 is configured to transmit light and the receiver 430 is configured to detect light. In one aspect, the receiver 430 provides a signal to the processor 440, the signal comprising information about the received light. In one aspect, this information comprises 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.

[0137] In one aspect, the transmitter 420 and / or the receiver 430 includes 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 different frequencies. For example, a first emitter 420 transmits 760 nanometers of light, while a second emitter 420 transmits 830 nanometers of light. In one aspect, a single emitter 420 transmits both 760 nanometers of light and 830 nanometers of light. For example, a first receiver 430 detects 760 nanometers of light, while a second receiver 430 detects 830 nanometers of light. In one aspect, a single receiver detects both 760 nanometers of light and 830 nanometers of light.

[0138] 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.

[0139] Figure 6 A schematic cross-section of tissue 601 is depicted, showing 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 as light 614A at a first depth, while the remainder continues as light 612B. Similarly, a portion of light 612B is reflected as light 614B at a second depth, 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 deep tissue 601.

[0140] Still reference Figure 6 , receivers 620, 622, and 624 are placed 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 the particular receiver. In one aspect, by comparing the information about the light detected by receiver 622 with one or both of light 614A and 614C received by receivers 620 and 624, information about the portion of the path of light 612B that is below light 612A and above light 612C is extracted. 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.

[0141] Figure 7 7 and 8. Depicted are 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 transmitter 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 transmitter to the respective receiver.

[0142] 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 to a single signal to capture information about light that has traveled on different paths.

[0143] Figure 8 Depicted are example paths 812A, 812B, and 812C of reflected light with a wide angle source in an emitter 810 in accordance with the present disclosure. The wide angle source emits light in a solid angle, such as a 30 degree cone angle. 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.

[0144] Light beams 812A, 812B, and 812C are each emitted at different angles. At 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 corresponding light beams 812A, 912B, and 812C toward a common receiver 820. Similarly, at 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 time and intensity information about the light that has traveled along multiple paths from emitter 810.

[0145] Fig. 9 Depicts a device similar to Figure 8 FIG. 9 is an example of a system of transmitting a signal 910 and detecting signals 914A and 916C. In this example, the transmitter transmits a light pulse 940 comprising two frequencies of light. Light of a first wavelength 914A is detected as pulse 944A, and light of a 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.

[0146] 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.

[0147] Fig. 10A and10B Depicted are detected signals of light reflected from oxygenated hemoglobin 1020 and deoxygenated hemoglobin 1010 at various points in a wound in accordance with the present disclosure. Fig. 10A is a representation of a real continuous signal, and Fig. 10B It is a representation of a calculation performed by measuring at discrete points on the same line.

[0148] exist Fig. 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 information provided by sum 1060 indicates fair-to-poor perfusion at location 1030, giving a different perspective than ratio 1050, which indicates a higher oxygenation level. In practice with existing ratio methods, it is generally believed that a high level of oxygenation is 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 of the high level of oxygenation site is actually not good, while the perfusion of the low level of oxygenation site is actually better.

[0149] Still reference Fig. 10B , at location 1040, the oxygenation ratio 1052 indicates that the oxygenation level is below optimal, while the perfusion sum 1062, which is the sum of the intensities of the two wavelengths, indicates that the 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.

[0150] Fig.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 may be drawn along the wound in any direction. On the one hand, any number of positions can be identified along the measurement line, for example, up to 100 positions, for example 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. On the one hand, the positions identified along the line can be spaced approximately equidistantly. On the one hand, the positions identified along the line can be spaced unevenly. On the one hand, the subgroups of the positions identified along the line can be spaced approximately equidistantly. On the one hand, the subgroups of the positions identified along the line can be spaced unevenly. On the one hand, multiple lines can be drawn along the wound for measurement. On the one hand, 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. On the one hand, the lines drawn along the wound can have about the same angle between them. On the one hand, the lines drawn along the wound can have different angles between them. On the one hand, the subgroups of the lines drawn along the wound can have about the same angle between them. In one aspect, subsets of lines drawn along the lesion may have different angles between them.

[0151] Fig. 11C According to the present disclosure Fig.11A and 11B1100 of 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 a given position point) 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 values ​​of curves 1101 and 1102 and are plotted with reference to the right vertical axis "perfusion".

[0152] In one aspect, when evaluating the state of the 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 continues to attempt to remove the necrotic tissue in area 150, then reference is made to 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 the healing and final state of the wound.

[0153] In this example, the outermost measurement point (at Fig.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. Fig. 11C , line 1150 represents the value of the maximum sum of the measurements made at the two frequencies in this example, which is sum 1140 in this example. If the line of measurement points extends beyond the visible part of the wound injury, the outermost measurement point may cover unaffected healthy tissue. The measurement made at a point above the healthy tissue forms a baseline value, and the measurement in the affected part can be compared with the baseline value. Similarly, the sum of the measurements made at two frequencies at a point above the healthy tissue forms the baseline sum. Since damaged tissue inherently has a perfusion different from normal perfusion, whether it is an increased perfusion in a hyperemic area or a decreased perfusion in a stagnant or necrotic area, comparing the sum of a point in the affected part around the wound with the sum of healthy tissue will improve the accuracy of the assessment. By comparing the two sums 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 suffering from general blood loss. Comparing the affected part with the healthy part can better understand the extent of the damage.

[0154] 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.

[0155] Fig.11E An example curve 1107 of perfusion sum values ​​obtained from another wound (not shown) in accordance with the present disclosure is depicted. Sum value 1172 has been obtained from known healthy tissue. Sum value 1174 is obtained closer to the wound, and the increase in value compared to the value of 1174 indicates that this location is within a hyperemic zone. The near zero value of sum value 1176 indicates that it may be within a necrotic zone. Values ​​of 1178 and 1180 that 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 as to the nature of the underlying tissue at and between the measurement points.

[0156] If the measurement location is within a hyperemic area, the summed value may be higher than that of healthy tissue. Fig. 11C The "baseline" value of line 1150 in is chosen to be the outermost point, such as Fig.11D 1140, or from a point specifically selected as a location above unaffected healthy tissue. In one aspect, the baseline value compared to the other sum values ​​is a value associated with known healthy tissue, which may not be the maximum sum value.

[0157] In one aspect, a user can take repeated measurements to map areas of hyperemia, as indicated by a sum value (e.g., perfusion) that is above a baseline value for known healthy tissue. The location can be captured by manual methods (e.g., 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 a user can trigger a mark to be applied to the skin. The user can do this manually. In one aspect, the perfusion measurement device can automatically apply a mark when the sum 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 entered by the user.

[0158] exist Fig.11E In the example of , the baseline value will be selected as value 1172, and the delta value will be calculated for the sum values ​​1174, 1176, 1178, and 1180. In one aspect, the delta value will be reported as a positive value for point 1174 and a negative value for points 1176, 1178, and 1180. In one aspect, the polarity of the delta value is reversed. In one aspect, only the absolute value of the delta is reported.

[0159] In one aspect, multiple measurements are taken at selected positions at each selected wavelength. In one aspect, according to the present disclosure, multiple measurements taken at selected positions at each selected wavelength are averaged prior to summing. In one aspect, each set of measurements consisting of measurements taken at selected positions 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.

[0160] 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 part from the baseline value. On the one hand, the Δ value is determined by subtracting the minimum sum value at a certain part from the baseline value. On the one hand, the Δ value is determined by subtracting the minimum sum value at a certain part 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.

[0161] Fig.11D Depicts an example wound 1105 and Fig. 11C Points 1140, 1142, 1144, 1146, and 148 correspond to Fig.11A and 11B The positions of 1120, 1122, 1124, 1126 and 1128. The necrosis area 1164 and the hyperemia area 1160 reflect the information provided by the line 1141. The area 1162 schematically shows the necrosis comparison area associated with the oxygenation line 1131, which is larger and wider than the perfusion guide area 1164.

[0162] Fig. 12A , 12B , 12C and 12D depict examples of the disclosed device according to the present disclosure.

[0163] Fig. 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.

[0164] Fig. 12B An example bandage 1210 is depicted in which a transmitter 1202 and a receiver 1204 are disposed 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.

[0165] Fig. 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.

[0166] Fig.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.

[0167] Fig.13 1300 is a flow chart of an exemplary method of perfusion measurement according to the present disclosure. The process proceeds from a start step 1302 to a 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 from comparing signals from multiple receivers arranged around a single transmitter. In a step 1306, which may be performed before or in parallel with step 1304, a location is determined. Step 1308 sums the measurements associated with oxygenated and deoxygenated hemoglobin. Step 1310 optionally adjusts the summed value by comparing with information about light reaching the receiver via alternate paths through the tissue. The original value and the adjusted value are recorded in step 1312. If more readings are to be taken around the injury site, the process goes to 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 that would be associated with healthy tissue and various other measurements around the common location. These delta values ​​are plotted at step 1322 and represent the degradation of perfusion compared to the baseline of healthy tissue of the same patient acquired at the same time and location using the same instrument by the same user. The process terminates at step 1324 "end".

[0168] Choosing a strategy for intervention in tissue injury using perfusion or oxygenation measurements

[0169] Fig.14Depicted is an overall process 1400 from admission to discharge from a nursing facility according to the present disclosure, the process being used to select a wound treatment strategy based on measured perfusion or oxygenation values ​​of blood in 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, 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. 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 house or other residence, and therefore, the "admission" step 1402 will be the first assessment of the patient by a nurse or other caregiver in his or her home. In one aspect, the schedule of interventions and assessment intervals used in a home environment can be different from the corresponding interventions and intervals used in a hospital.

[0170] In one aspect, in process 1400, a newly admitted patient receives an entry assessment in step 1404, the assessment comprising: 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 to deoxygenated wavelengths measured during the perfusion measurement. In one aspect, the SpO2 value is considered to be a location rather than a single point, so that perfusion measurements can be taken at spatially separated points in 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.

[0171] In one aspect, once the evaluation step is completed, a determination is made in step 106 whether the patient's readings are abnormal, i.e., whether the combination of the results of the various elements of the evaluation indicates that the patient has or is at risk of developing further wound tissue damage. Each element of the evaluation can have a separate risk level criterion, such as a scoring system with a threshold indicating an unacceptable risk. In one aspect, there is a protocol for combining criteria to generate a composite parameter that can be used to select a level of intervention.

[0172] In one aspect, if it is determined that the patient is 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 will be re-evaluated at least using the perfusion or oxygenation measurement protocol at a frequency associated with level 0 or otherwise at a time interval in step 1414. The process 1400 then loops back to step 1406 to evaluate the results of the perfusion or oxygenation measurement performed in step 1414.

[0173] In one aspect, if it is determined in step 1406 that the patient has an abnormal reading, the process proceeds 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 typically having shorter intervals. In this example, the process has been defined by a hospital or other governing organization so that one level is set to a Level 1 intervention at this point. In another aspect, step 1422 may implement a Level 2 or higher level 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 is in the range of 1 to n, n being the highest defined level of intervention and monitoring.

[0174] 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 moves to step 1442. In this example, step 1442 continues to implement the current intervention level, and the process loops through steps 1440 to 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 reduced based on the magnitude of the delta value. In one aspect, if the oxygenation measurement consistently remains at an oxygenation level of 95% or above, the patient's condition is improving.

[0175] On the one hand, if the patient does not show improvement in step 1434, the process moves 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 precursory indicators of wound enlargement. The open wound itself is treated in step 1448, and this second cycle 1444-1446-1448-1450 continues until the wound is closed, at which point the process returns to step 1430.

[0176] In one aspect, at any time in process 100, the patient is discharged to step 1418, where the patient's condition at the time of discharge or transfer is recorded. In one aspect, step 1418 includes a last set of perfusion measurements taken at one or more locations on the patient's body. In one aspect, a last set of oxygenation measurements are 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.

[0177] In one aspect, the present disclosure provides and includes a method for identifying and treating a patient requiring wound intervention, the method comprising the following steps: upon admission to a care facility, assessing the patient's risk of tissue damage, 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.

[0178] In one aspect, the present disclosure provides and includes a method for identifying and treating a patient in need of a wound intervention, the method comprising the steps of: assessing the patient's risk of tissue damage upon admission to a care facility, wherein the assessing step comprises: performing a first plurality of SpO2 measurements in the patient; determining whether any of the first plurality of SpO2 measurements is below a first threshold; if the first plurality of SpO2 measurements is at or above the first threshold, applying a level 0 first intervention; if any of the first plurality of SpO2 measurements is below 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 first threshold for the SpO2 measurement is about 95%. In one aspect, the first threshold SpO2 measurement is about 95.5%, about 96%, about 96.5%, 97%, about 97.5%, or about 98%.

[0179] In one aspect, a first plurality of perfusion measurements are taken at and around one or more anatomical sites selected from the group consisting of: flesh tissue over the patient's sternum, sacrum, heels, scapulae, elbows, ears, and other bony prominences. In one aspect, a first plurality of perfusion measurements are taken at and around one or more anatomical sites at risk for tissue damage. In one aspect, a first plurality of perfusion measurements are taken at and around all anatomical sites at risk for tissue damage. Fig.29A , 29B, 29C and 29D show the location of tissue damage risk at different locations of the patient, shown as circles. In one aspect, a first plurality of perfusion measurements are made at and around one or more anatomical sites in chronic contact with the medical device, the anatomical sites selected from the group consisting of: cheeks, 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 are made. In one aspect, the first plurality of perfusion measurements are made at locations located on one or more concentric circles centered about the anatomical site. In one aspect, the first plurality of perfusion measurements are made at locations located on a straight line approximately equidistant from the anatomical site.

[0180] In one aspect, the first delta value is determined by a difference between a maximum perfusion value and a minimum perfusion value from a first plurality of perfusion measurements collected. 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 according to the location 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 than ten 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.

[0181] In one aspect, the delta value may be calculated from 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 made 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 made 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 may be calculated from a portion of a set of perfusion values ​​generated from multiple perfusion measurements at a single location, and the delta value may be calculated as the maximum difference between the average and a single perfusion value for the same set. In one aspect, the delta value may be calculated as the ratio of the maximum perfusion value to the minimum perfusion value within a set of perfusion values.

[0182] 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 according to 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.

[0183] 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.

[0184] 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.

[0185] In one aspect, a Level 1 (N=1) intervention is applied to a patient who has 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.

[0186] In one aspect, a Level 2 (N=2) intervention 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.

[0187] In one aspect, a Level 3 (N=3) intervention is applied to patients who have a Δ value that exceeds a threshold by no more than 200% of a threshold, such as no more than 195% of a threshold, no more than 190% of a threshold, no more than 185% of a threshold, no more than 180% of a threshold, no more than 175% of a threshold, no more than 170% of a threshold, no more than 165% of a threshold, no more than 160% of a threshold, no more than 155% of a threshold, no more than 150% of a threshold, no more than 145% of a threshold, no more than 140% of a threshold, no more than 135% of a threshold, no more than 130% of a threshold, no more than 125% of a threshold, no more than 125% of a threshold, no more than 130% of a threshold, no more than 13 ... 0%, no greater than 115% of the threshold, no greater than 110% of the threshold, no greater than 100% of the threshold, no greater than 95% of the threshold, no greater than 90% of the threshold, no greater than 85% of the threshold, no greater than 80% of the threshold, no greater than 75% of the threshold, no greater than 70% of the threshold, no greater than 65% of the threshold, no greater than 60% of the threshold, no greater than 55% of the threshold, no greater than 50% of the threshold, no greater than 45% of the threshold, no greater than 40% of the threshold, no greater than 35% of the threshold, no greater than 30% of the threshold, no greater than 25% of the threshold, no greater than 20% of the threshold, no greater than 15% of the threshold, no greater than 10% of the threshold, or no less than 5% of the threshold. In one aspect, 3 levels of intervention are applied to the location where the measurement is taken.

[0188] In one aspect, a Level 4 intervention (N=4) is applied to patients who have a Delta value that exceeds a threshold by no more than 250% of a threshold, such as no more than 245% of a threshold, no more than 240% of a threshold, no more than 235% of a threshold, no more than 230% of a threshold, no more than 225% of a threshold, no more than 220% of a threshold, no more than 215% of a threshold, no more than 210% of a threshold, no more than 205% of a threshold, no more than 200% of a threshold, no more than 195% of a threshold, no more than 190% of a threshold, no more than 185% of a threshold, no more than 180% of a threshold, no more than 175% of a threshold, no more than 170% of a threshold, no more than 165% of a threshold, no more than 160% of a threshold, no more than 155% of a threshold, no more than 150% of a threshold, no more than 140% of a threshold, no more than 150% of a threshold, no more than 145% of a threshold, no more than 150 ... 5%, 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, 4 levels of intervention are applied to the location where the measurement is taken.

[0189] In one aspect, a Level 5 (N=5) intervention is 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% of the threshold, no more than 265% of the threshold, no more than 260% of the threshold, no more than 270% of the threshold, no more than 275% of the threshold, no more than 270 ... 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.

[0190] In one aspect, 6 levels of intervention (N=6) are applied to patients having 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 295% of the threshold, no more than 290% of the threshold, no more than 285% of the threshold, no more than 295% of the threshold, no more than 290% of the threshold, no more than 29 ... 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% of the threshold, 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 190% 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 100% of the threshold, 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, 6 levels of intervention are applied to the location where the measurement is taken.

[0191] In one aspect, a 7-level intervention (N=7) is applied to patients having a Δ value that exceeds a threshold by no more than 400% of a threshold, such as no more than 395% of a threshold, no more than 390% of a threshold, no more than 385% of a threshold, no more than 380% of a threshold, no more than 375% of a threshold, no more than 370% of a threshold, no more than 365% of a threshold, no more than 360% of a threshold, no more than 355% of a threshold, no more than 350% of a threshold, no more than 345% of a threshold, no more than 340% of a threshold, no more than 335% of a threshold, no more than 330% of a threshold, no more than 325% of a threshold, no more than 330% of a threshold, no more than 325% of a threshold, no more than 345% of a threshold, no more than 340% of a threshold, no more than 350% of a threshold, no more than 350% of a threshold, no more than 365% of a threshold, no more than 370% of a threshold, no more than 380% of a threshold, no more than 385% of a threshold, no more than 390% of a threshold 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.

[0192] In one aspect, an 8-level (N=8) intervention is applied to patients having a Delta value that exceeds a threshold by no more than 450% of a threshold, such as no more than 445% of a threshold, no more than 440% of a threshold, no more than 435% of a threshold, no more than 430% of a threshold, no more than 425% of a threshold, no more than 420% of a threshold, no more than 415% of a threshold, no more than 410% of a threshold, no more than 405% of a threshold, no more than 400% of a threshold, no more than 395% of a threshold, no more than 390% of a threshold, no more than 385% of a threshold, no more than 380% of a threshold, no more than 375% of a threshold, no more than 370% of a threshold, no more than 365% of a threshold, no more than 360% of a 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 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 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% of the threshold, no more than 240% 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 130% of the threshold, 125% of the threshold or less, 120% of the threshold or less, 115% of the threshold or less, 110% of the threshold or less, 100% of the threshold or less, 95% of the threshold or less, 90% of the threshold or less, 85% of the threshold or less, 80% of the threshold or less, 75% of the threshold or less, 70% of the threshold or less, 65% of the threshold or less, 60% of the threshold or less, 55% of the threshold or less, 50% of the threshold or less, 45% of the threshold or less, 40% of the threshold or less, 35% of the threshold or less, 30% of the threshold or less, 25% of the threshold or less, 20% of the threshold or less, 15% of the threshold or less, 10% of the threshold or less, or 5% of the threshold or less.In one aspect, 8 levels of intervention are applied to the location where the measurement is taken.

[0193] 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 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 455% of the threshold, no more than 450% of the threshold, 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 425% of the threshold, no more than 430% of the threshold, no more than 445% of the threshold, no more than 450% of the threshold 405% of the threshold, not greater than 400% of the threshold, not greater than 395% of the threshold, not greater than 390% of the threshold, not greater than 385% of the threshold, not greater than 380% of the threshold, not greater than 375% of the threshold, not greater than 370% of the threshold, not greater than 365% of the threshold, not greater than 360% of the threshold, not greater than 355% of the threshold, not greater than 350% of the threshold, not greater than 345% of the threshold, not greater than 340% of the threshold, not greater than 335% of the threshold, not greater than 330% of the threshold, not greater than 325% of the threshold, not greater than 320% of the threshold, not greater than 315% of the threshold, not greater than 310% of the threshold, not greater than 305% of the threshold, not greater than 300% of the threshold, not greater than 295% of the threshold %, not greater than 290% of the threshold, not greater than 285% of the threshold, not greater than 280% of the threshold, not greater than 275% of the threshold, not greater than 270% of the threshold, not greater than 265% of the threshold, not greater than 260% of the threshold, not greater than 255% of the threshold, not greater than 250% of the threshold, not greater than 245% of the threshold, not greater than 240% of the threshold, not greater than 235% of the threshold, not greater than 230% of the threshold, not greater than 225% of the threshold, not greater than 220% of the threshold, not greater than 215% of the threshold, not greater than 210% of the threshold, not greater than 205% of the threshold, not greater than 200% of the threshold, not greater than 195% of the threshold, not greater than 190% of the threshold, not greater than 185% of the threshold, not greater 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.

[0194] 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, %, not greater than 455% of the threshold, not greater than 450% of the threshold, not greater than 445% of the threshold, not greater than 440% of the threshold, not greater than 435% of the threshold, not greater than 430% of the threshold, not greater than 425% of the threshold, not greater than 420% of the threshold, not greater than 415% of the threshold, not greater than 410% of the threshold, not greater than 405% of the threshold, not greater than 400% of the threshold, not greater than 395% of the threshold, not greater than 390% of the threshold, not greater than 385% of the threshold, not greater than 380% of the threshold, not greater than 375% of the threshold, not greater than 370% of the threshold, not greater than 365% of the threshold, not greater than 360% of the threshold, not greater than 355% of the threshold, not greater than 350% of the threshold, not greater 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 made.

[0195] 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.

[0196] 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).

[0197] In one aspect, the evaluation step of the present disclosure further comprises performing a risk assessment. In one aspect, the risk assessment is performed according to a test selected from the group consisting of: Braden scale, Gosnell scale, Norton scale, and Waterlow scale. In one aspect, the evaluation step of the present disclosure further comprises performing an evaluation 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, transcutaneous water loss, and detecting the presence of interleukin-1 alpha at one or more anatomical sites of interest.

[0198] 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.

[0199] 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 reduction exceeding a second threshold; if the time delta value does not exceed the second threshold, continuing to apply 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 is a reduction exceeding the second threshold, applying 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 reduction exceeding the second threshold, performing a plurality of SpO2 measurements at a second predetermined frequency corresponding to the level M.

[0200] 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.

[0201] 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.

[0202] In one aspect, the second delta value is determined by a difference between a maximum perfusion value and a minimum perfusion value from a collected second plurality of 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, the second plurality of perfusion measurements consisting of a subset defined according to the location at which the measurements were taken.

[0203] 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, 3.4, 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, 5.1 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 of the SpO2 measurement can be about 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.

[0204] 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.

[0205] 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.

[0206] On the one hand, an M-level intervention is selected according to

[0143] to

[0153] , with N replaced by M.

[0207] In one aspect, the present disclosure further provides and includes: determining whether the second Δ value is less than a third threshold, applying an (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.

[0208] 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 an (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.

[0209] 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, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4. 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 about 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 may be greater than the first threshold. In one aspect, the third threshold may be less than the first threshold.

[0210] In one aspect, the second Δ 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.

[0211] In one aspect, the present disclosure provides and includes a method of 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 that the patient is receiving; 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 perform 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, wherein the value of N is greater than K; and if the delta value exceeds the first threshold, performing 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 who is experiencing a change in care, a change in mobility, a change in nutrition, a change in 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 analgesics or sacral analgesics during surgery. In one aspect, a patient in need thereof is a patient who undergoes an operation 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 operation lasts one or more hours, such as two or more hours, or three or more hours.

[0212] 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] .

[0213] 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.

[0214] 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 a threshold value established for (K+1) is greater than the amount by which the delta value exceeds a threshold value established for K. In one aspect, the amount by which the delta value exceeds a threshold value established for (K-1) is less than the amount by which the delta value exceeds a threshold value established for K.

[0215] In one aspect, a K-level intervention is selected according to

[0181] to

[0190] , with N replaced by K.

[0216] 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 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.

[0217] On the one hand, the second threshold is determined according to

[0199] .

[0218] In one aspect, the present disclosure provides and includes: determining whether any of a plurality of SpO2 measurements are above a threshold range corresponding to level K; if any of the plurality of SpO2 measurements are above the threshold range corresponding to level K, applying a level L intervention, where L is a non-negative value less than K; and if any of the plurality of SpO2 measurements are above the threshold range corresponding to level K, taking a plurality of perfusion measurements at a predetermined frequency corresponding to level L. 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%.

[0219] 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, 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, 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, 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, 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, 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, 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.On the one hand, 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.

[0220] 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 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 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 rearranging patient groups based on the level of care assigned to each patient.

[0222] In one aspect, the present disclosure provides and includes a method for reducing the incidence of tissue damage in patients admitted to a nursing facility, the method comprising the following steps: upon admission to the nursing facility, assessing the risk of tissue damage in the patient, 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 includes a method of reducing the incidence of wound development in a patient admitted to a care facility, the method comprising the steps of: assessing the patient's risk of tissue damage upon admission to the care facility, wherein the assessing step comprises: taking a first plurality of SpO2 measurements in 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; applying a level 0 first intervention if the first plurality of SpO2 measurements is above or equal to the first threshold; and applying 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 patients in the care 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.

[0223] In one aspect, the present disclosure provides and includes a method of identifying and treating a patient who needs to apply a skin 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 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 an hour if the delta value exceeds the threshold.

[0224] In one aspect, the present disclosure provides and includes a method for identifying and treating a patient who needs to apply a skin cream to their heels, 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 skin cream to the patient's heel if any of the multiple SpO2 values ​​is below the threshold; and taking multiple SpO2 measurements every two hours if any of the multiple SpO2 measurements is below the threshold.

[0225] In one aspect, the present disclosure provides and includes a method of identifying and treating a patient who needs neuromuscular stimulation applied to his 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 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, if the delta value exceeds the threshold, taking a plurality of perfusion measurements at least once every half hour.

[0226] In one aspect, the present disclosure provides and includes a method for identifying and treating a patient in need of neuromuscular stimulation applied to his or her 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 neuromuscular stimulation to the patient's heel if any of the multiple SpO2 measurements is below the threshold; and taking multiple SpO2 measurements every hour if any of the multiple SpO2 measurements is below the threshold.

[0227] In one aspect, the present disclosure provides and includes a method of identifying and treating a patient who needs to have a topical cream applied to his or her 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.

[0228] In one aspect, the present disclosure provides and includes a method of identifying and treating a patient who needs to have a topical cream applied to his or her 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.

[0229] In one aspect, the present disclosure provides and includes a method for identifying and treating a patient who needs a heel boot applied to his 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; if the Δ value exceeds the threshold, applying a heel boot to the patient's heel; and if the Δ value exceeds the threshold, taking multiple perfusion measurements every half hour.

[0230] In one aspect, the present disclosure provides and includes a method for identifying and treating a patient who needs a heel boot applied to his 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 the heel boot to the patient's heel if any of the multiple SpO2 measurements is below the threshold; and taking multiple SpO2 measurements every half hour if any of the multiple SpO2 measurements is below the threshold.

[0231] In one aspect, the present disclosure provides and includes a method of identifying and treating a patient who needs to apply a skin 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 level N, where N is greater than or equal to 2; if the delta value exceeds the threshold, applying a skin cream to the patient's sacrum; and if the delta value exceeds the threshold, taking a plurality of perfusion measurements every six hours. 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.

[0232] 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.

[0233] In one aspect, the present disclosure provides and includes a method of identifying and treating a patient who needs neuromuscular stimulation 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; if the delta value exceeds the threshold, administering neuromuscular stimulation to the patient's sacrum; and if the delta value exceeds the threshold, taking a plurality of perfusion measurements every four hours. In one aspect, if the delta value exceeds the threshold, taking a 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.

[0234] 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.

[0235] In one aspect, the present disclosure provides and includes a method of identifying and treating a patient who needs to have a topical 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 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, if the delta value exceeds the threshold, taking a plurality of perfusion measurements at least once an hour or at least once every half an hour.

[0236] In one aspect, the present disclosure provides and includes 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.

[0237] In one aspect, the present disclosure provides and includes a method of identifying and treating a patient in need of therapeutic ultrasound being applied thereto, 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 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: flesh tissue over the patient's sternum, sacrum, heel, scapula, elbow, ear, and other bony prominences.

[0238] In one aspect, the present disclosure provides and includes a method of identifying and treating a patient in need of applying therapeutic ultrasound thereto, 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 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: flesh tissue over the patient's sternum, sacrum, heel, scapula, elbow, ear, and other bony prominences.

[0239] In one aspect, the present disclosure provides and includes a method of identifying and treating a patient to whom shock wave therapy is to be applied, 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 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: flesh tissue over the patient's sternum, sacrum, heel, scapula, elbow, ear, and other bony prominences. In one aspect, the shock wave therapy is provided by electromagnetic pulses or pressurized air.

[0240] In one aspect, the present disclosure provides and includes a method of identifying and treating a patient in need of applying shock wave therapy thereto, 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 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: flesh tissue over the patient's sternum, sacrum, heel, scapula, elbow, ear, and other bony prominences. In one aspect, the shock wave therapy is provided by electromagnetic pulses or pressurized air.

[0241] In one aspect, the present disclosure provides and includes a method of identifying and treating a patient who needs a 30 degree wedge applied thereto, 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.

[0242] In one aspect, the present disclosure provides and includes a method of identifying and treating a patient who needs to have a 30 degree wedge applied thereto, 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.

[0243] In one aspect, the present disclosure provides and includes a method of identifying and treating a patient in need 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.

[0244] In one aspect, the present disclosure provides and includes a method of identifying and treating a patient who needs to be applied 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.

[0245] In one aspect, the present disclosure provides and includes a method of 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 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: flesh tissue over the patient's sternum, sacrum, heel, scapula, elbow, ear, and other bony prominences.

[0246] In one aspect, the present disclosure provides and includes a method of identifying and treating a patient to whom a hybrid mattress is to be applied, 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: flesh tissue over the patient's sternum, sacrum, heel, scapula, elbow, ear, and other bony prominences.

[0247] In one aspect, the present disclosure provides and includes a method of 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: flesh tissue 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 of identifying and treating a patient who needs to be applied 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 tissue over the patient's sternum, sacrum, heel, scapula, elbow, ear, and other bony prominences.

[0249] 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 following steps: providing a motion sensor including an accelerometer and a gyroscope sensor; monitoring the patient's activity frequency and range; 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.

[0250] 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 measurement. In one aspect, targeted therapy is provided to a general site of wound development, the site selected from the group consisting of: toes, heels, sacrum, spine, elbows, scapula, occipital bone, and ischial tuberosity. In one aspect, targeted therapy is simultaneously provided to a second general site of wound development, the site selected from the group consisting of: toes, heels, sacrum, spine, elbows, scapula, occipital bone, and ischial tuberosity. In one aspect, a first site that receives targeted therapy is known to cause wound development at a second site.

[0251] Compare bilaterally symmetrical perfusion measurements to identify damaged tissue

[0252] Fig.22A The sacral region of the back of patient 1910 is depicted. A symmetry line 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 symmetry line 1912 and is approximately the same height, and is therefore considered a bilaterally symmetrical position on the back of patient 1910.

[0253] Fig. 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) and the observer was standing at the foot of the bed. With respect to the soles 22L and 22R of the feet 20L and 20R, the positions 24L and 24R are located at approximately equal positions, such as the same distance from the back (i.e., the heel) and the same distance from the inner side of the corresponding foot 20L or 20R, and are considered to be bilaterally symmetrical positions.

[0254] Fig. 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 located on the respective soles 22L and 22R of feet 20L and 20R. In one aspect, locations 26R and 30R are considered to be bilaterally symmetrical relative to foot 20R when considered alone without reference to foot 20L.

[0255] Without being limited to a particular theory, comparison of perfusion measurements taken at bilaterally symmetrical locations may compensate for deviations in readings for a particular patient from a population of patients. For example, a patient may be dehydrated on a particular day when the measurements are taken. Comparison of perfusion values ​​from healthy tissue from the same patient when in a dehydrated state 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, comparison of readings taken at bilaterally symmetrical locations will exclude "common mode" effects of dehydration variations at both locations and provide a more reliable indication of damaged tissue at one location.

[0256] like Figure 4 The perfusion measurement device 400 provided in can be used to make 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 relative 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 measurements made at multiple locations or parameters associated with or derived from the measurements, such as one or more of the following: a difference between each of the differences, averages, or common averages of perfusion values ​​derived from the multiple measurements, respectively. In one aspect, the device 400 includes a display that is configured to display one or more parameters associated with the measurements, such as a delta between perfusion values ​​derived from measurements made at two bilaterally symmetrical locations.

[0257] In one aspect, the device 400 utilizes two receivers 430A and 430B to measure substantially simultaneously. In one aspect, the device 400 measures sequentially, wherein the time interval between measurements is zero to one second or longer. In one aspect, the measurement of the device 400 is triggered by actuating a button or an actuator. In one aspect, the measurement of the device 400 is automatically triggered based on an input from a switch element as a part of the device 400, the switch element being, for example, a contact sensor, a pressure sensor, an optical sensor or other type of proximity detection device positioned adjacent to one or more of the receivers 430A and 430B in one aspect. In one aspect, multiple switch elements must be activated simultaneously to provide input to measure. In one aspect, the device 400 includes a processor, the processor is coupled to the circuit and receives information about the measured reflected light from the circuit. 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 multiple receivers and is configured to directly measure the reflected light. In one aspect, the processor is configured to convert multiple received reflected light measurements into multiple 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.

[0258] In one aspect, the measured reflected light parameter is related to the perfusion of blood in the epidermis at a depth of the patient, the depth being determined by the spatial geometry of the receivers 430A and 430B, the wavelength or wavelengths of light emitted by the transmitter 420, and other operating characteristics of the device 400. In one aspect, the magnitude of the reflected light detected by the receiver 430 is equal to the perfusion having 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 changing one or more operating characteristics between readings, thereby providing information related to perfusion at various depths of the skin.

[0259] 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 made. 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, an indication of damage is located at a location associated with a larger one of the perfusion values. In one aspect, an indication of damage is located at a location associated with a smaller one of the perfusion values. In one aspect, determining whether tissue damage is present includes one or more of: comparing each perfusion value 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 may 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, 3.4, 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, 5.1 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 the predetermined value based on a given perfusion unit. In one aspect, the ranges and threshold values ​​disclosed herein vary according to: a specific bilaterally symmetrical location, the 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).

[0260] One or more regions may be defined on the body. On the one hand, measurements taken within a region are considered equivalent to one another. A region may be defined as a site on the skin of the body where measurements may be taken at any point within the site. On the one hand, a region corresponds to an anatomical region (e.g., heel, ankle, lower back). On the one hand, a region may 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. On the one hand, a region may include multiple discontinuous sites on the body. On the one hand, a set of specific locations may include points in multiple discontinuous sites.

[0261] In one aspect, the region is defined by the 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 50cm 2 Between 10 and 50 cm 2 Between 10 and 25 cm 2 Between or 5 to 25cm 2 between.

[0262] In one aspect, measurements can be taken in a specific pattern or a portion thereof. In one aspect, a pattern with a target area of ​​interest centered is used as a reading pattern. In one aspect, measurements are 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 the body by defining a first measurement position of the pattern relative to an anatomical feature, wherein the remaining measurement positions of the pattern are defined as offsets from the first measurement position.

[0263] 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.

[0264] In one aspect, a threshold value may 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 other values ​​may be established for at least one region. In one aspect, a delta value is identified as significant when a plurality of measured delta values ​​taken within a region meet or exceed a threshold value associated with the region. In one aspect, each of a plurality of regions has a different threshold value. In one aspect, two or more regions may have a common threshold value.

[0265] In one aspect, the threshold has both a delta value component and a temporal order component, wherein the delta value is identified as significant when the delta value 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 produced a delta value greater than or equal to the predetermined value out of 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 produced 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.).

[0266] In one aspect, the threshold has a trending aspect, wherein changes in the delta values ​​of a plurality of consecutive measurements are compared to one another. In one aspect, the trending threshold is defined as a predetermined change in the delta values ​​over a predetermined length of time, wherein a determination that the threshold has been reached or exceeded is significant. In one aspect, the determination of significance will result in an alarm being issued. In one aspect, a trend line may be calculated based on a portion of individual measurements in a plurality of consecutive measurements. In one aspect, a trend line may be calculated based on a portion of the delta values ​​of a plurality of consecutive measurements.

[0267] In one aspect, the number of measurements taken in a single zone can be less than the number of measurement locations defined in the pattern. In one aspect, the delta value will be calculated after a predetermined initial number of readings have been taken in the zone, which is less than the number of measurement locations defined in the pattern, and after each additional reading in the same zone, wherein no additional readings will be taken once the delta value reaches or exceeds a threshold associated with the zone.

[0268] 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.

[0269] In one aspect, a quality metric may be generated for each of the multiple measurements. In one aspect, this quality metric is selected to evaluate the repeatability of the measurement. In one aspect, this quality metric is selected to evaluate the skill of the clinician performing the measurement. In one aspect, the quality metric may include one or more statistical parameters, such as an average, mean, or standard deviation. In one aspect, the quality metric may include one or more of comparing each measurement to a predetermined range. In one aspect, the quality metric may include comparing each measurement to a pattern of values, for example, comparing a measurement at a predetermined location to a range associated with each predetermined location. In one aspect, the quality metric may include determining which measurements were made on healthy tissue, and one or more assessments of consistency in a subset of this "healthy" measurement, such as a range, standard deviation, or other parameter.

[0270] 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 computer, or smartphone, such as via a Bluetooth, WiFi, or Ethernet connection. Fig.13 shown.

[0271] In one aspect, the device 400 includes two receivers 430A and 430B located at separate locations on the device body. An example usage is to place the device 400 against the patient's body to position the first receiver 430A at a first body location and simultaneously position the 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 the receivers 430A and 430B at a fixed separation distance from each other and in a fixed orientation. In one aspect, the receivers 430A and 430B are aligned on a common plane.

[0272] In one aspect, the device body of device 400 is flexible so that receivers 430A and 430B can be oriented at an angle to each other. In one aspect, one or more of receivers 430 are movable so 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 so that the separation distance between receivers 430A and 430B can be changed. In one aspect, the device body of device 400 is rigid so that the angle and separation distance between the receivers are not changeable.

[0273] In one aspect, the device 400 includes a plurality of transmitters 420 and a plurality of receivers 430 to form 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 arranged. In one aspect, the transmitters 420 and receivers 430 are embedded in 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 cover 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 sizes and types of the transmitters 420 within the array are different. In one aspect, the sizes and types of the receivers 430 within the array are different. 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 the electronic components directly or through a cable. In one aspect, the electronic assembly includes a circuit coupled to the receiver 430 and a processor coupled to the circuit. 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 the 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., detection of a person standing on the mat due to detection of the person's weight by the pressure sensor) initiates measurement by one or more receivers 430. In one aspect, the receiver 430 operates in a "detection mode" capable of detecting when a person steps on the mat, and transitions to a "measurement mode" when it is determined 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 the patient's skin when the patient is lying in bed, such as against the patient's back or against the sole of one or both of the patient's feet. In one aspect, the mat includes one or more of a support tray, a reinforcing element, and a conformal pad to help place the receiver 430 against the surface of the patient's skin.

[0274] In one aspect, the two emitters 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 emitters 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, 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%.

[0275] On the one hand, two receivers can overlap 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%. On the one hand, two receivers can overlap 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%.

[0276] In one aspect, the planar array can further include a plurality of contact sensors on the same planar surface as each receiver 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 plurality of combinations of these sensors. 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.

[0277] Fig.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, Fig.23A Receivers 430 are presented at non-overlapping locations labeled "A" through "H" in FIG. The perfusion values ​​measured at each location are Fig. 23B 20R. In this example, the perfusion values ​​for positions "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 positions "B" and "G" are higher because the receiver 430 overlaps a portion of the contact site 2050R at those locations. The perfusion values ​​for positions 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 symmetrical relative to the centerline 2052R of the right foot 20R. In one aspect, a similar set of measurements made at locations A'-H' on the left foot 20L can determine that locations on each of the feet 20L and 20R, such as locations E and E', are approximately bilaterally symmetrical.

[0278] Fig.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 has the ability to communicate wirelessly 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 the 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 the 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 doctor who is providing care to the patient.

[0279] Trending of perfusion measurements to detect tissue damage

[0280] Fig.25Perfusion values ​​over time for a patient at risk for developing a pressure sore in accordance with the present disclosure are depicted. 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 within a 24 hour period, such as within 18 hours, within 12 hours, within 8 hours, within 6 hours, within 4 hours, within 3 hours, within 2 hours, within 1 hour, within 45 minutes, within 30 minutes, within 15 minutes, within 10 minutes, within 5 minutes, within 1 minute, or within 30 seconds.

[0281] Curve 2210 represents the average perfusion values ​​for a group of patients at high risk of developing a pressure sore during the days leading up to developing a pressure sore 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 sore during the days prior to day 0, where no pressure sores developed on day 0. In both cases, there was no sign of damage or indication of future development of a pressure sore 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.

[0282] Fig.26 Depicted are perfusion delta values ​​over time for patients who develop pressure sores in accordance with the present disclosure. Curves 2302 and 2304 show the acceleration of the rate of increase (i.e., slope) of the curves as time gets closer to the point at which visual inspection leads to a clinical diagnosis. Curve 2310 is the average of the other curves and shows an upward curve, i.e., an acceleration of the rate of increase.

[0283] Fig. 27 is an example graph of measured and calculated perfusion values ​​in accordance with the present disclosure. Curve 2410 is a set of perfusion values ​​for a skin site that is susceptible to developing a pressure sore. Curve 2420 is a matched set of perfusion values ​​for a second skin site that is proximal to the first site but is not at risk for developing a pressure sore. Curve 2420 is used 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.

[0284] Tissue damage can be detected in several ways. In one aspect, the slope of the 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 degree of damage is indicated. There may be multiple slopes for assessing multiple degrees of tissue damage. In one aspect, the slope is determined relative to any two points on the perfusion curve 2410 and compared to the slope of line 2412 to indicate a degree of damage. In one aspect, the slope is determined by taking the derivative of the perfusion curve 2410. In one aspect, the slope of line 2412 is determined by 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 degree of damage.

[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 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.

[0286] 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 derivative between the most recent SpO2 value and the immediately previous SpO2 value; comparing this derivative to a threshold; and if the derivative exceeds the threshold, determining that tissue damage is present.

[0287] 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 multiple levels of tissue damage.

[0288] 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 most recent SpO2 averages; calculating the curvature of the fitted curve; comparing this curvature to a threshold; and if the curvature exceeds the threshold, determining that tissue damage is present.

[0289] 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 values ​​of the present disclosure vary depending on the particular 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.

[0290] In one aspect, the slope of the 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 degree of damage is indicated. There may be multiple slopes for assessing multiple degrees of tissue damage. In one aspect, the slope is determined relative to any two points on the delta curve 2430 and compared to the slope of line 2432 to indicate a degree of damage. In one aspect, the slope of line 2432 is determined by 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 degree of damage.

[0291] 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 the time when the perfusion delta value first equals or exceeds this threshold and the development of visible symptoms of a pressure sore can be a first duration. The first duration can be 5 days or more, such as 6 days or more, 7 days or more, 8 days or more, 9 days or more, or 10 days or more.

[0292] On the other hand, when the perfusion delta curve shows an upward bend or other deviation from a linear progression, visible symptoms may occur in a shorter period of time, 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 used to generate a perfusion delta value for a specific location on the patient's skin (e.g., a heel), the device including a receiver 430 and electronics to measure reflected light and convert this reflected light measurement into a perfusion value and store a plurality of these perfusion values, then calculate and display a perfusion delta value based on the plurality of perfusion values, and transmit a portion of the measurement and the delta value to a remote computer. These perfusion delta values ​​are tracked and analyzed for trends in the perfusion delta values, i.e., the slope and curvature of a curve connecting these perfusion delta values. In one aspect, the amount by which the incremental perfusion delta value is above a linear prediction based on previous perfusion delta values ​​is compared to a predetermined threshold. In one aspect, the amount by which the incremental perfusion delta value is above the 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.

[0293] In one aspect, the trend analysis may disregard a single perfusion delta value that is below a threshold if both the previous and subsequent perfusion delta values ​​are above the threshold.

[0294] 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 fit curve needs to intersect the most recent perfusion delta value.

[0295] Having now generally described the invention, the same will be more readily understood by reference to the following examples which are provided by way of illustration and are not intended to limit the disclosure unless otherwise specified.

[0296] Examples

[0297] Example 1: Levels of intervention for treating a heel pressure ulcer

[0298] Subjects identified as at risk for heel pressure ulcers were treated according to the following regimen:

[0299] Table 1: Example intervention protocol for treating heel pressure ulcers

[0300]

[0301]

[0302] Example 2: Levels of intervention for treating sacral pressure ulcers

[0303] Subjects identified as at risk for sacral pressure ulcers were treated according to the following regimen:

[0304] Table 2: Example intervention protocol for treating sacral pressure ulcers

[0305]

[0306] Example 3: Example process for selecting intervention and monitoring levels

[0307] Fig.15 1 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 a plurality of perfusion measurements at a location on a patient's skin, where each measurement 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 plurality of perfusion measurements.

[0308] 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 performed 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.

[0309] 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 moves to step 1512 and then to step 1514 to implement intervention and measurement intervals associated with level N+1, respectively. In this example, the value of N is zero or greater.

[0310] 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 Fig.15 The “≥” shown in .

[0311] Example 4: Workflow Guidance Matrix

[0312] Fig.16 is an example of a workflow guidance matrix 1600 in which a current intervention level 1602 and a 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, a level of 0 (zero) is associated with patients who are considered to be at no risk for developing tissue damage. For example, higher intervention and monitoring levels can be determined by ranking the intervention levels based on cost, difficulty of implementation, or other parameters determined by the care organization. When a caregiver takes a new set of perfusion measurements, they query this matrix by identifying the row of 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 the row 1602 and the column 1604. When selecting the intervention level for the next time period, the caregiver can consider the intervention level that has been determined, as well as the current intervention level and delta value.

[0313] 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 adjacent cells.

[0314] Example 5: Progression of tissue conditions leading to wound development

[0315] Fig.17 Schematic diagram 1700 of delta values ​​for a single patient at a single location of wound development is shown. Perfusion values ​​are measured by a device for evaluating blood perfusion in tissue beneath the patient's skin. The delta values ​​are generated from a set of perfusion measurements taken at incremental times. Point 1772 is a measurement at time = 0, where all perfusion values ​​have a baseline value 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, and therefore, there is no indication of significant sub-surface damage.

[0316] At time t2, the damage progresses and the delta value 1776 is greater than the threshold 1762, indicating that significant damage is present. This damage is still not visible on the skin. Nevertheless, the delta value greater than the threshold 1762 indicates that cellular damage is present at a depth less than the sensitive depth of the perfusion measurement device.

[0317] 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 the healthy tissue remains approximately the same as during the previous measurement, this reduces the perfusion value obtained over the damaged site, thereby reducing the calculated delta value 1778.

[0318] 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.

[0319] 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 the perfusion value of healthy tissue. This results in a negative delta value 1780. In some cases, a negative delta will indicate that the tissue is severely damaged. In some cases, a negative delta will indicate that a portion of the tissue at the location of the lowest perfusion value is necrotic.

[0320] Example 6: Method I for mapping potential injury sites

[0321] Fig.18A is an example of a method of mapping a site of possible injury. The site of injury 1800 is surrounded by healthy tissue 1808. The central site 1830 is severely damaged. The first peripheral site 1820 has less damage, and the second peripheral site 1810 has less damage, but is still non-healthy tissue. The skin over all of these sites has the same appearance and texture, with no indication of subsurface damage. A series of dashed circles 1840, 1842, 1844, 1846, 1848, and 1850 indicate a set of example locations where perfusion measurements are made. Perfusion measurements made at locations 1840, 1842, and 1850 typically produce perfusion values ​​associated with healthy tissue, identified as "H" in this example. Perfusion measurements made at locations 1844 and 1848 typically produce perfusion values ​​"J" that are slightly higher than H. Perfusion measurements made at location 1846 typically produce perfusion values ​​"P" that are greater than J. These measurements can be made 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 that a significant lesion is present at this location. The exact location of the largest lesion may be close to the measurement location 1846 that produced the maximum perfusion value.

[0322] Example 7: Method for mapping potential injury sites II

[0323] Fig.18B A second example of mapping a possible injury site is depicted. In this example, based on, for example, the previous application Fig.18A The method shown learns 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 ​​produced by the measurements in 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 produced at location 1864 is slightly higher than the perfusion values ​​produced 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 produced 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 produces a perfusion value similar to the perfusion value for location 1870 and is sufficient to identify the boundary as being outside of location 1874 without requiring another measurement at a location corresponding to location 1872.

[0324] 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.

[0325] Example 8: Treatment decision pathway for stratifying patients and providing appropriate treatment

[0326] Fig.19AThe currently recommended treatment decision pathway for preventing pressure ulcers in hospitalized patients as set out by the National Institutes for Health and Care Excellence (NICE) in its clinical guideline Pressure ulcers: prevention and management (published 23 April 2014) is outlined. The guideline recommends a risk analysis for each patient admitted to a nursing facility who exhibits one or more risk factors such as significant limitation of mobility, significant loss of sensation, previous or current pressure ulcers, poor nutrition, inability to reposition oneself, or significant cognitive impairment. Risk assessment is typically performed using a scoring checklist (such as the Braden scale) that rates the severity of specific risk factors.

[0327] After completing the risk assessment, the patient is 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 classification, the patient will receive a different sequence of treatments and visual assessments.

[0328] All people are at risk of developing pressure sores. They are more likely to occur in people who are seriously ill or who have neurological problems, mobility impairments, poor nutrition, poor posture, or deformities.

[0329] Pressure ulcers are classified as Stage 1 to Stage 4, with Stage 1 being the mildest condition. The National Pressure Ulcer Advisory Panel (NPUAP) has defined a "Stage 1" ulcer as intact skin with localized areas of nonblanchable erythema, where "blanchable" means that 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, blanching erythema, or changes in feel, temperature, or firmness may precede visual changes.

[0330] Visual Skin Assessment (VSA) is the current method for identifying pressure ulcers. Trained health care professionals evaluate the appearance of the skin visually and tactilely, looking for redness, or changes in tissue firmness, tissue temperature, or moisture.

[0331] If a patient is identified as being at low risk for developing a pressure ulcer, the patient will only need to be monitored for changes in 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 distribution cushion. If there is no change in clinical status, the low-risk patient will not be re-evaluated according to this set of guidelines, but will remain on the same treatment and assessment pathway until he or she is discharged from the healthcare facility.

[0332] If a patient is identified as being at risk of developing a pressure ulcer, a plan is to turn or 'turn' the patient every 6 hours. As with low-risk patients, a high-specification foam pad may be provided if the patient uses a wheelchair or sits for long periods of time. No other monitoring or intervention is recommended by the NICE guidelines.

[0333] High risk patients receive a high specification foam mattress as a precaution, and if they use a wheelchair or sit for long periods of time, a high specification cushion is provided, and they will be turned every 4 hours. Patients will receive daily VSA for all body areas. If a site is found to have non-blanchable erythema, appropriate intervention will be implemented and the site will be re-examined by VSA every 2 hours. Sites that do not have non-blanchable erythema will be examined daily by VSA. A personalised care plan will be developed for each high risk patient.

[0334] From this flow chart it can be seen that the caregiver will spend the majority of his / her time with the high risk patients. While this may be appropriate, it results in at-risk patients not being monitored and they may progress to a stage 1 ulcer before the caregiver detects the condition. Furthermore, the consequence of relying on the VSA to detect the problem necessarily means that the patient will progress to a stage 1 ulcer before an intervention is chosen or administered. By the time the lesion has progressed to stage 1, even with intervention, the skin may still break down and become a stage 2 ulcer. Clearly, tissue damage needs to be identified early so that intervention can prevent sub-epidermal lesions from progressing to stage 1 and worse.

[0335] Fig.19B is an example of a current enhanced treatment decision pathway currently being implemented in some healthcare settings for the prevention of pressure ulcers. The enhanced pathway adds monitoring steps to both the at-risk and low-risk pathways. Low-risk patients receive weekly risk assessments, such as completing a Braden scale assessment. Patients identified as at-risk during the initial assessment will receive a high-specification foam mattress as a preventative measure and will be assessed daily via VSA. A care plan will be developed for monitoring and treating patients at risk. If the patient is at high risk, no changes are made to care.

[0336] The benefit of an enhanced program is that all patients will be screened for pressure ulcers. However, the additional steps will require additional time, additional staff, or further burden existing staff. Fig.19A The recommended care pathway, however Fig.19B The care pathway requires more resources and remains limited by the fact that patients are bound to develop a stage 1 ulcer before the injury is recognized by VSA.

[0337] Hospitals and nursing facilities use different numbers of risk categories, ranging from two categories, low risk and high risk, to four or more categories. Fig.19BThe patient is assigned to each category based on the results of the initial risk assessment.

[0338] Fig. 20 is an example flow chart according to the present disclosure, which shows how a device for evaluating blood perfusion in tissue beneath a patient's skin can be used in a stand-alone 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) of 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 made at separate locations at and around each body location, although this is generally referred to as making multiple measurements at the body location. The perfusion measurement device calculates a "Δ" value for each location based on a set of measurements made 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.

[0339] In one aspect, the clinician will perform perfusion measurements at a first time interval for body locations that were identified as potentially having damage 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 for 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 changes in attendance or shift changes, 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.

[0340] In one aspect, the intervals at which perfusion measurements are performed are 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 in a previous perfusion scan, and 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 (the second threshold is greater than the first threshold).

[0341] 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 it is visible on VSA, it is a no-brainer to provide basic protection to even the healthiest patients.

[0342] Patients at risk (will be included in Fig.19A and 19B Patients identified as high risk in the current care pathway of the patient will receive specialized care based on the body position that exhibits a delta value above a threshold. For example, if the delta value for the sacral body position is above a threshold, the patient will be repositioned every 6 hours and receive perfusion measurements at the sacrum daily, and perfusion measurements at other body positions weekly.

[0343] Fig.21 is an example flow chart according to the present disclosure, which shows how an apparatus for evaluating blood perfusion in tissue beneath the skin of a patient can be used as an aid to further improve Fig.19B An enhanced treatment decision pathway for a patient receiving a hospital admission receives a risk assessment and perfusion scan of all body locations determined by the hospital for monitoring, and the process of assigning the patient to a risk category is based in part on the risk assessment and in part on the perfusion scan results. An initial delta value greater than a threshold indicates that an injury may be present at that body location. In one aspect, the assignment is based only on the maximum initial delta value found during the initial perfusion scan.

[0344] The decision whether to implement an intervention, such as turning the patient over at a first time interval, is currently based on the VSA and risk assessment despite uncertainty as to whether an early injury is present beneath the skin. In one aspect, the decision to implement an intervention for 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 implemented 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 implement an intervention may be higher or lower than the threshold for determining that an injury may exist at a body location.

[0345] Compare Fig.19A , 19B , 20, and 21, demonstrate one of the benefits of monitoring patients with perfusion measurement devices. 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 $2000.

[0346] The baseline for this comparison is Fig.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 estimated to be 5.6 days, with an average cost per patient of $26, the cost of care for at-risk patients was estimated to be an average of $121, and the cost for high-risk patients was estimated to be $165. All care pathways rely on VSA to detect pressure ulcers and implement interventions based on the progression of a “typical” patient rather than the specific patient’s condition.

[0347] like Fig.21 As shown, incorporating a perfusion measurement device into the current “best practice” workflow 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 a perfusion scan to the no-risk care pathway is $2, increasing the cost from approximately $26 to $28. The expected cost of care for an at-risk patient who does not have any elevated perfusion delta values ​​(i.e., no subepidermal tissue damage) also increases by only $2. 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 increases from $165 to $169. Although it may seem like a small additional cost, it provides a higher level of protection for at-risk patients.

[0348] Fig. 20 Figure 2 shows 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 $4, while Fig.21 The cost of the comprehensive low-risk care pathway is $28. Fig. 20 The only other category in the perfusion measurement device care pathway is $97, while Fig.21 The cost of the comprehensive care pathway for at-risk and high-risk patients was $123-$169.

[0349] Example 9: Perfusion delta trend at a patient's heel indicates pressure ulcer onset

[0350] Prior to any visual diagnosis of a pressure ulcer on the heel, 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 outward away from the body and toward the side of the body. A receiver of the perfusion detection device is placed on the inside of the heel. The receiver is adjusted to be in 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.

[0351] Fig.28 The perfusion delta values ​​for seven (7) patients before they were diagnosed with one or both heels developing a pressure ulcer are shown. The trends for the different patients were time-shifted to coincide with Day 0 following the pressure ulcer diagnosis event. 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. Fig.28As shown, these seven patients exhibited a peak in perfusion delta values ​​two (2) to four (4) days prior to 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.

[0352] Example 10: Intervention Levels Based on Oxygenation Measurements

[0353] Subjects identified as being at risk for pressure ulcers were treated according to the following regimen:

[0354] Table 3: Example intervention options for treating patients at risk for pressure ulcers

[0355]

[0356] 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:

[0357] Embodiment 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 at the same time; 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.

[0358] Embodiment 2. A device according to embodiment 1, wherein the first receiver is spaced apart from the transmitter by a first distance, the first distance being selected so that light emitted by the transmitter and received by the first receiver is reflected from a first depth below the patient's skin.

[0359] Embodiment 3. The device according to embodiment 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.

[0360] 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.

[0361] 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.

[0362] Embodiment 6. The device of Embodiment 5, wherein the first source and the second source can be activated independently.

[0363] 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.

[0364] Embodiment 8. The apparatus of Embodiment 7, wherein: the processor is individually coupled to each of the first detector and the second detector, and the first signal comprises individual signals from the first and second detectors.

[0365] Embodiment 9. A device according to any one of embodiments 1 to 8, wherein: the processor is coupled to the transmitter, the transmitter is configured to emit light when receiving a gating pulse, the processor is configured to provide the gating pulse to the transmitter and the first receiver, the first receiver is further configured to measure a first time period from receiving the gating pulse to receiving light from the transmitter, and the first signal includes information about the first time period.

[0366] 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.

[0367] 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.

[0368] Embodiment 12. The apparatus of embodiment 10, wherein the processor is further configured to determine a percentage value of each sum value relative to a maximum sum value in the series of sum values.

[0369] Embodiment 13. A device according to any one of embodiments 1 to 12, further comprising an accelerometer, the accelerometer being 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 is 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.

[0370] Embodiment 14. A method for evaluating blood perfusion in tissue beneath the skin of a patient, the method comprising the following steps: emitting light toward 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.

[0371] Embodiment 15. The method according to embodiment 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.

[0372] Embodiment 16. The method according to embodiment 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.

[0373] Embodiment 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 to 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 so that the substrate can be positioned so that the light emitted by the emitter illuminates a portion of the skin of the patient 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.

[0374] Embodiment 18. A device according to embodiment 17, wherein: the processor is coupled to the transmitter, and the processor is further configured to cause the transmitter 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.

[0375] Example 19. A method for identifying and treating a patient in need of 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.

[0376] Embodiment 20. A method according to embodiment 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.

[0377] Embodiment 21. A method according to embodiment 19, wherein the step of performing a first plurality of perfusion measurements comprises: performing perfusion measurements of a first subset at the first position and performing perfusion measurements of at least one additional subset at the second position; the step of calculating a first Δ value comprises: calculating the first Δ value for the first position based on a portion of the measurements of the first subset, and calculating the first Δ value for the second position 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 position exceeds a first threshold for the first position, and determining whether the first Δ value for the second position exceeds a first threshold for the second position; the step of applying a level 0 first intervention comprises: applying a level 0 intervention specific to the first position if the first Δ for the first position does not exceed the first threshold for the first position, and applying a level 0 intervention specific to the second position if the first Δ for the second position does not exceed the first threshold for the second position; and the step of applying a level N first intervention comprises: applying a level N intervention specific to the first position if the first Δ for the first position exceeds the first threshold for the first position, and applying a level N intervention specific to the second position if the first Δ for the second position exceeds the first threshold for the second position.

[0378] Embodiment 22. The method of embodiment 19, wherein the evaluating step further comprises performing a visual assessment.

[0379] Embodiment 23. The method of embodiment 22, wherein the patient has no visible symptoms of the wound.

[0380] Embodiment 24. The method of embodiment 19, wherein the evaluating step further comprises performing a risk assessment.

[0381] Embodiment 25. The method according to embodiment 19, wherein the value of N is equal to 1.

[0382] 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.

[0383] Embodiment 27. The method according to embodiment 19, wherein the value of N does not exceed 10.

[0384] Embodiment 28. The method of Embodiment 19, wherein the Level N first intervention is a more intensive intervention than the Level 0 first intervention.

[0385] 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; if the second Δ value exceeds the second threshold, applying a second intervention of level M, where M is an integer and M is greater than N; and if the second Δ value exceeds the second threshold, performing multiple perfusion measurements at a second predetermined frequency corresponding to level M.

[0386] Embodiment 30. The method of embodiment 29, wherein the second threshold is the same as the first threshold.

[0387] Embodiment 31. A method according to Embodiment 29, wherein the second threshold is greater than the first threshold.

[0388] Embodiment 32. A method according to embodiment 29, wherein the value of M is equal to N+1 but not more than 10.

[0389] Embodiment 33. The method of Embodiment 29, wherein the value of M is proportional to the amount by which the second Δ value exceeds the second threshold.

[0390] 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, performing an (N-1) level intervention if the second Δ value is less than the third threshold value 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 value.

[0391] 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.

[0392] 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.

[0393] Embodiment 37. The method of embodiment 36, wherein the level 1 intervention is providing the patient with a heel boot.

[0394] Embodiment 38. The method of Embodiment 36, wherein the Level 2 intervention is changing the patient's support surface.

[0395] Embodiment 39. The method of embodiment 36, wherein the level 3 intervention is application of a dressing to the back or side of the patient's heel.

[0396] Embodiment 40. The method of embodiment 36, wherein the level 4 intervention is changing the patient's bed sheets to low friction sheets.

[0397] Embodiment 41. The method of embodiment 36, wherein the level 5 intervention is providing a low friction mattress surface to the patient's lower leg.

[0398] Embodiment 42. The method of Embodiment 36, wherein the Level 6 intervention is turning the patient at shorter intervals than currently provided.

[0399] Embodiment 43. The method of embodiment 36, wherein the level 7 intervention is applying skin cream to the patient's heel.

[0400] Embodiment 44. The method of embodiment 36, wherein the level 8 intervention is applying neuromuscular stimulation to the patient's heel.

[0401] Embodiment 45. The method of embodiment 36, wherein the level 9 intervention is applying a topical cream to the patient's heel to enhance perfusion.

[0402] Embodiment 46. The method of embodiment 36, wherein the level 10 intervention is providing a silicone pad to the patient's calf.

[0403] Embodiment 47. The method of Embodiment 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.

[0404] Embodiment 48. The method of Embodiment 47, wherein 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.

[0405] Embodiment 49. The method of Embodiment 47, wherein the Level 2 intervention is changing the patient's mattress to a pressure-reducing mattress.

[0406] Embodiment 50. The method of Embodiment 47, wherein the Level 3 intervention is application of a dressing to the patient's sacrum.

[0407] Embodiment 51. The method of embodiment 47, wherein the level 4 intervention is changing the patient's mattress to a powered mattress.

[0408] Embodiment 52. The method of embodiment 47, wherein the level 5 intervention is applying skin cream to the patient's sacrum.

[0409] Embodiment 53. The method of embodiment 47, wherein the level 6 intervention is application of neuromuscular stimulation to the patient's sacrum.

[0410] Embodiment 54. The method of embodiment 47, wherein the level 7 intervention is application of a topical cream to the patient's sacrum to enhance perfusion.

[0411] Embodiment 55. The method of embodiment 47, wherein the level 8 intervention is providing a silicone pad under the patient's body.

[0412] Embodiment 56. The method of Embodiment 19, wherein the level 0 predetermined frequency is once every 24 hours.

[0413] Embodiment 57. The method of Embodiment 19, wherein the level 1 predetermined frequency is once every 10 hours.

[0414] Embodiment 58. The method of Embodiment 19, wherein the Level 2 scheduled frequency is the beginning of each nursing shift.

[0415] Embodiment 59. The method of Embodiment 19, wherein the Level 3 predetermined frequency is once every 12 hours.

[0416] Embodiment 60. The method of Embodiment 19, wherein the Level 4 predetermined frequency is once every 8 hours.

[0417] Embodiment 61. The method of Embodiment 19, wherein the level 5 predetermined frequency is once every 6 hours.

[0418] Embodiment 62. The method of embodiment 19, wherein the predetermined frequency of level 6 is once every 4 hours.

[0419] Embodiment 63. The method of embodiment 19, wherein the predetermined frequency of level 7 is once every 2 hours.

[0420] Embodiment 64. The method according to embodiment 19, wherein the predetermined frequency of level 8 is once every 1 hour.

[0421] Embodiment 65. The method of embodiment 19, wherein the level 9 predetermined frequency is once every 0.5 hours.

[0422] 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 apply the current intervention; if the Δ value does not exceed the first threshold, continuing to perform multiple perfusion measurements at a predetermined frequency corresponding to the level K; if the Δ value exceeds the first threshold, applying 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.

[0423] Embodiment 67. A method according to embodiment 66, wherein the value of N is equal to K+1 but not more than 10.

[0424] Embodiment 68. A method according to Embodiment 66, wherein the value of N is proportional to the amount by which the Δ value exceeds the first threshold.

[0425] 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.

[0426] Embodiment 70. A method according to Embodiment 69, wherein the value of L is equal to L-1.

[0427] Embodiment 71. A method according to Embodiment 69, wherein the value of L is selected based on the amount that the Δ value is less than the second threshold.

[0428] Embodiment 72. The method of Embodiment 66, wherein the patient in need is a patient undergoing a change in care.

[0429] Embodiment 73. The method of Embodiment 66, wherein the patient in need thereof is a patient experiencing changes in mobility.

[0430] Embodiment 74. The method of embodiment 66, wherein the patient in need thereof is a patient undergoing nutritional changes.

[0431] Embodiment 75. The method of Embodiment 66, wherein the patient in need thereof is a patient experiencing changes in sensory perception.

[0432] Embodiment 76. The method of embodiment 66, wherein the patient in need thereof is a patient who develops an open ulcer.

[0433] Embodiment 77. The method of embodiment 66, wherein the patient in need thereof is a patient recovering from an open ulcer.

[0434] Embodiment 78. The method of Embodiment 66, wherein the patient in need is a patient undergoing surgery.

[0435] Embodiment 79. The method of Embodiment 66, wherein said patient receives spinal analgesics during said surgery.

[0436] Embodiment 80. The method of Embodiment 78, wherein said patient receives sacral analgesics during said surgery.

[0437] Embodiment 81. The method of Embodiment 78, wherein the surgery lasts for more than 4 hours.

[0438] Example 82. A method for selecting a wound treatment for a patient, 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 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.

[0439] Example 83. A method for stratifying patient groups in a care 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.

[0440] Example 84. A method for reducing the incidence of wound development in patients admitted to a nursing facility, the method comprising the following steps: upon admission to the nursing facility, assessing the patient's risk of tissue damage, 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.

[0441] Embodiment 85. The method of Embodiment 84, wherein the incidence of wound development in patients in the care facility is reduced by 1 / 100.

[0442] Example 86. A method for identifying and treating a patient who needs to have skin cream applied to his or her heels, 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; if the Δ value exceeds the threshold, applying skin cream to the patient's heel; and if the Δ value exceeds the threshold, performing multiple perfusion measurements every two hours.

[0443] Example 87. A method for identifying and treating a patient who requires neuromuscular stimulation to his or her 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; if the Δ value exceeds the threshold, applying neuromuscular stimulation to the patient's heel; and if the Δ value exceeds the threshold, performing multiple perfusion measurements every hour.

[0444] Embodiment 88. A method for identifying and treating a patient who requires application of a topical cream to his or her 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; if the Δ value exceeds the threshold, applying a topical cream to the patient's heel; and if the Δ value exceeds the threshold, taking multiple perfusion measurements every half hour.

[0445] Example 89. A method for identifying and treating a patient who needs to have skin cream applied to his or her 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; if the Δ value exceeds the threshold, applying skin cream to the patient's sacrum; and if the Δ value exceeds the threshold, performing multiple perfusion measurements every six hours.

[0446] Example 90. A method for identifying and treating a patient who requires neuromuscular stimulation to be applied to his or her 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; if the Δ value exceeds the threshold, applying neuromuscular stimulation to the patient's sacrum; and if the Δ value exceeds the threshold, performing multiple perfusion measurements every four hours.

[0447] Example 91. A method for identifying and treating a patient who requires application of a topical cream to his or her sacrum, the method comprising the steps of: taking 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; if the Δ value exceeds the threshold, applying a topical cream to the patient's sacrum; and if the Δ value exceeds the threshold, taking multiple perfusion measurements every two hours.

[0448] 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 position on the patient's skin and a second perfusion value corresponding to reflected light measured by the second receiver at a second position on the patient's skin, wherein the second position is bilaterally symmetrical relative to the first position.

[0449] 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.

[0450] 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.

[0451] Embodiment 95. The apparatus of Embodiment 92, further comprising a gap between the first and second receivers.

[0452] 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 transmitters 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, which, 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.

[0453] Example 97. An apparatus as described in Example 96, wherein the instructions further include the steps of: determining a difference between the first and second perfusion values; and if the difference is greater than a predetermined threshold, providing an indication of tissue damage at one of the first and second locations.

[0454] Example 98. An apparatus as described in 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.

[0455] 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, which, when executed on the processor, perform the step of determining the difference between the first perfusion value and the second perfusion value.

[0456] Embodiment 100. The device of Embodiment 99, wherein each of the two receivers is disposed at opposite ends of the device body while being aligned on a common plane.

[0457] Embodiment 101. The device of Embodiment 99, wherein the device body is rigid and holds the two receivers at a fixed separation distance from each other and in a fixed orientation.

[0458] 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.

[0459] Embodiment 103. A device according to Embodiment 102, wherein the device body includes a hinge.

[0460] Embodiment 104. The apparatus of Embodiment 99, wherein the first reflected light measurement and the second reflected light measurement are measured simultaneously.

[0461] Embodiment 105. The device of Embodiment 104, wherein the device 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.

[0462] Embodiment 106. The device of Embodiment 105, wherein the contact sensor is a pressure sensor or an optical sensor.

[0463] 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.

[0464] Embodiment 108. An apparatus according to Embodiment 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.

[0465] 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.

[0466] 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.

[0467] Embodiment 111. The apparatus of Embodiment 109, further comprising: determining the larger of the first and second perfusion values; and providing an indication of tissue damage at the location associated with the larger perfusion value if the difference exceeds a predetermined threshold.

[0468] 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 the slope between the most recent perfusion value and the immediately previous perfusion value; comparing this slope to a threshold; and determining that tissue damage exists if the slope exceeds the threshold.

[0469] 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 exists if the slope exceeds the threshold.

[0470] Embodiment 114. A method for detecting tissue damage before tissue 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 the 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 if the curvature exceeds the threshold, determining that tissue damage exists.

[0471] Although the present invention has been described with reference to specific aspects, it will be appreciated by those skilled in the art that various changes may be made and equivalents may be substituted for its elements without departing from the scope of the present invention. In addition, various modifications may be made to the specific circumstances or materials of the teachings of 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 the present invention will include all aspects falling 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 selectively emit light of a first wavelength or emit light of a second wavelength, a camera configured to form a first image of the reflected light of the first wavelength and a second image of the 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 light emitted by the emitter illuminates a portion of the patient's skin within the field of view of the camera, Display, and a processor coupled to the camera and the display and configured to: receiving the first and second images, forming a third image as the sum of the first and second images, and The third image is provided on the display.

2. The apparatus according to claim 1, wherein: The processor is coupled to the transmitter, The processor is 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.

3. An apparatus 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 the reflected light of the first wavelength and a second image of the 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 light emitted by the emitter illuminates a portion of the patient's skin within the field of view of the camera, Display, and a processor coupled to the camera and the display and configured to: receiving the first and second images, and The first and second images are provided on the display.

4. The apparatus according to claim 3, wherein: The processor is coupled to the transmitter, The processor is 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.

Images