WO2007030379A2 - Systeme de mesure automatique de la pression d'une perfusion cutanee - Google Patents

Systeme de mesure automatique de la pression d'une perfusion cutanee Download PDF

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Publication number
WO2007030379A2
WO2007030379A2 PCT/US2006/034116 US2006034116W WO2007030379A2 WO 2007030379 A2 WO2007030379 A2 WO 2007030379A2 US 2006034116 W US2006034116 W US 2006034116W WO 2007030379 A2 WO2007030379 A2 WO 2007030379A2
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WO
WIPO (PCT)
Prior art keywords
perfusion
pressure
cuff
measurement
measurements
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Application number
PCT/US2006/034116
Other languages
English (en)
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WO2007030379A8 (fr
WO2007030379A3 (fr
Inventor
Daniel J. Bartnik
Brandon W. Reynolds
Irvin T. Pierskalla
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Optical Sensors Incorporated
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from PCT/US2005/031505 external-priority patent/WO2006031479A1/fr
Application filed by Optical Sensors Incorporated filed Critical Optical Sensors Incorporated
Priority to EP06790131A priority Critical patent/EP1933697A4/fr
Priority to JP2008530108A priority patent/JP5147700B2/ja
Publication of WO2007030379A2 publication Critical patent/WO2007030379A2/fr
Publication of WO2007030379A3 publication Critical patent/WO2007030379A3/fr
Publication of WO2007030379A8 publication Critical patent/WO2007030379A8/fr

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Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/02—Detecting, measuring or recording pulse, heart rate, blood pressure or blood flow; Combined pulse/heart-rate/blood pressure determination; Evaluating a cardiovascular condition not otherwise provided for, e.g. using combinations of techniques provided for in this group with electrocardiography or electroauscultation; Heart catheters for measuring blood pressure
    • A61B5/026—Measuring blood flow
    • A61B5/0261—Measuring blood flow using optical means, e.g. infrared light
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/68—Arrangements of detecting, measuring or recording means, e.g. sensors, in relation to patient
    • A61B5/6801—Arrangements of detecting, measuring or recording means, e.g. sensors, in relation to patient specially adapted to be attached to or worn on the body surface
    • A61B5/683—Means for maintaining contact with the body
    • A61B5/6832—Means for maintaining contact with the body using adhesives
    • A61B5/6833—Adhesive patches
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/68—Arrangements of detecting, measuring or recording means, e.g. sensors, in relation to patient
    • A61B5/6801—Arrangements of detecting, measuring or recording means, e.g. sensors, in relation to patient specially adapted to be attached to or worn on the body surface
    • A61B5/684—Indicating the position of the sensor on the body
    • A61B5/6842—Indicating the position of the sensor on the body by marking the skin
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/68—Arrangements of detecting, measuring or recording means, e.g. sensors, in relation to patient
    • A61B5/6801—Arrangements of detecting, measuring or recording means, e.g. sensors, in relation to patient specially adapted to be attached to or worn on the body surface
    • A61B5/6843—Monitoring or controlling sensor contact pressure
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/72—Signal processing specially adapted for physiological signals or for diagnostic purposes
    • A61B5/7203—Signal processing specially adapted for physiological signals or for diagnostic purposes for noise prevention, reduction or removal
    • A61B5/7207—Signal processing specially adapted for physiological signals or for diagnostic purposes for noise prevention, reduction or removal of noise induced by motion artifacts
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/145—Measuring characteristics of blood in vivo, e.g. gas concentration, pH value; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid, cerebral tissue
    • A61B5/1455—Measuring characteristics of blood in vivo, e.g. gas concentration, pH value; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid, cerebral tissue using optical sensors, e.g. spectral photometrical oximeters
    • A61B5/14551—Measuring characteristics of blood in vivo, e.g. gas concentration, pH value; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid, cerebral tissue using optical sensors, e.g. spectral photometrical oximeters for measuring blood gases
    • A61B5/14552—Details of sensors specially adapted therefor

Definitions

  • the present invention relates to a system for the automated measurement of skin perfusion pressure of a local or regional body site. More particularly the invention relates to a system that includes a measuring means for measuring capillary blood flow and placement means for assuring reproducibility, pressure means for applying pressure to a tissue site having capillary blood flow and means for measuring the applied pressure, and means for determining the relationship therebetween that detects and rejects motion artifact and indicates an SPP value.
  • Skin perfusion pressure measurements are taken to determine whether local blood flow, i.e. capillary perfusion, of a local or regional body site . having an ulcer or wound is sufficient to support wound healing.
  • the accurate measurement of this parameter therefore, is critical to physicians who treat patients suffering from open surface wounds resulting from complications from diabetes, pressure ulcers, burns, accidents, and the like.
  • U.S. Pat. No. 6,178,342 to Borgos et al. discloses a surface perfusion pressure instrumentation used in conjunction with a laser Doppler probe that measures the "amount" of moving blood contained within a microvascular observation volume in percent tissue hematocrit. This measurement is taken as a function of applied pressure.
  • the laser Doppler optical probe defines an observation volume in the skin near the surface of the patient and a pressure cuff is used to manually apply pressure to the limb near the optical probe.
  • the laser Doppler sensor is placed against the skin under a pneumatic cuff that is secured to the affected limb, i.e. toe, ankle, arm, leg, etc.
  • a user using an inflation bulb manually inflates the pneumatic cuff.
  • the inflation pressure must be sufficiently high to stop local blood flow at the site of the optical probe.
  • a display instrument is coupled to the optical probe typically via a fiber optic cable, and to the inflation bulb through a tube. Deflation starts and the optical probe monitors the number of moving red blood cells moving into or out of the observation volume without regard to velocity.
  • the number of moving red blood cells detected within the control volume is expressed as a percent and displayed on the display monitor. This value is shown as both a numeric value and a bar graph on the Y-axis.
  • the instrument also measures the pressure within the cuff and displays the applied cuff pressure in millimeters of mercury on the X-axis of the display.
  • a moving bar chart along the X-axis shows the operator which cuff pressure is currently being measured. As pressure is slowly manually released, an indicator of blood flow return is provided in bar chart form. While a technician conducts the test, a physician interprets the data displayed on the display monitor.
  • FIG. 2A illustrated in FIG. 2A is a display from a prior art monitor.
  • the physician conducting the skin perfusion test will likely record the value of skin perfusion pressure as forty-five millimeters of mercury.
  • FIG. 2B again illustrates a display from a prior art monitor with the perfusion measurement rising in percent value as the cuff pressure decreases.
  • motion artifact is now displayed at forty-five millimeters of mercury.
  • a physician conducting the skin perfusion test may erroneously record the value of skin perfusion pressure as forty-five millimeters of mercury.
  • a further problem with conventional devices is that reproducibility is inhibited because when repeated measurements are needed the laser Doppler optical probe is not necessarily placed at the same site. Consequently, the surface perfusion pressure measurements may vary because the sensor is typically placed on a different site having different microcirculatory flow. For example, fiber optic probes may be placed directly on the surface of a patient's tissue underneath the pressure cuff. If repeated measurements are necessary, the fiber optic probe or sensor may not be placed on the same site in subsequent measurements.
  • Another problem that exists with conventional systems is that the laser Doppler probe or sensor is sometimes placed underneath the pressure cuff or distal to the pressure cuff for measurement. Because the laser Doppler sensor is measuring the transmission of light, it would be ideal to provide for a device that is useful in eliminating ambient light from the measurement site.
  • a new and improved skin perfusion system that includes a sensor placement device and that automatically inflates and deflates the pressure cuff, controls inflation and deflation, and detects and rejects motion artifact, and automatically determines an SPP value is needed.
  • an object of the present invention to overcome the problems and disadvantages of the surface perfusion pressure instruments of the prior art. It is, therefore, an object of the present invention to automate the measurement of skin perfusion pressure and generate an SPP value.
  • the system includes capillary blood flow measuring means in communication with a tissue site having capillary blood flow therewithin; pressure means for simultaneously applying controllable pressure to said capillary blood flow measuring means and the tissue, the pressure means responsive to an automated sequence, the automated sequence comprising (i) occluding capillary blood flow within said tissue; and (ii) controllably releasing said pressure while capillary blood flow returns; measuring means for measuring the applied controllable pressure; and display means for displaying the relationship between said applied controllable pressure and said capillary blood flow, said display means in communication with said capillary blood flow measuring means and said applied controllable pressure means.
  • a sensor placement device for securing the capillary blood flow means to the tissue site is provided.
  • a skin perfusion pressure monitoring system that automatically calculates the SPP value from perfusion measurements.
  • the monitoring system controls and measures cuff pressure and closely controls the rate of cuff deflation during the critical deflation portion of the skin perfusion pressure test cycle.
  • the monitoring system uses a perfusion sensitive tolerance that progressively adjusts sensitivity thresholds as perfusion returns. This allows for measurements of perfusion over a wide dynamic range while being less sensitive to motion transients.
  • the monitoring system actively controls the rate of cuff deflation and determines when motion is severe enough to affect this rate. The test is ended if motion is determined to be too severe.
  • the monitoring system monitors duration of perfusion change. As microcirculation returns it produces a perfusion signal that changes from baseline flow. Motion aritfact, on the other hand, produces a perfusion signal that has greater oscillatory content.
  • the monitoring system monitors the profile of perfusion change. As both macrocirculation and microcirculation normal flow resumes, it produces a change in perfusion signals that have recognizable and differentiable patterns. Motion artifact, on the other hand, produces a perfusion signal that is generally random, short-lived, and has more oscillatory content. Therefore, changes that do not follow a perfusion return signature are ignored by the monitoring system of the present invention.
  • perfusion return signatures that do not have a signature amenable to the automated qualification of an SPP value and the data can be displayed for the physician to interpret. For example, non-reactive hyperemia is a circulatory condition that results in such a known perfusion pattern.
  • FIG. 1 is a schematic representation of the perfusion pressure monitor in use with a patient
  • FIG. 2A is a schematic diagram of a prior art display monitor illustrating bars in a normal test progression
  • FIG. 2B is a schematic diagram of a prior art display monitor illustrating motion artifact as a spiked bar
  • FIG. 3 is a flowchart representing the operation of the perfusion pressure monitor with respect to inflation
  • FIG. 4 is a flowchart representing the operation of the perfusion pressure monitor with respect to deflation
  • FIG. 5A is a schematic diagram illustrating the pressure line output display of the skin perfusion pressure monitoring system in accordance with the present invention.
  • FIG. 5B is a schematic diagram illustrating the pressure line output display of the skin perfusion pressure monitoring system in accordance with the present invention with a spike indicating motion artifact;
  • FIG. 5C is a schematic diagram illustrating the pressure line output display of the skin perfusion pressure monitoring system in accordance with the present invention with a spike indicating motion artifact, bars, and a true reading of surface perfusion pressure.
  • FIG. 5D is a schematic diagram illustrating the pressure line output display in a circulatory condition known as non-reactive hyperemia.
  • FIG. 6 is a top view of a sensor placement device in accordance with the present invention.
  • FIG. 7 is a perspective view of a sensor placement device having an SPP sensor positioned therewithin in accordance with the present invention.
  • FIG. 8 is a top plan view of an alternative embodiment of a sensor placement device.
  • equate perfusion means the perfusion criteria used to continue the cuff inflation sequence. This criterion ensures that there is proper contact between the probe and the patient's skin. It is typically perfusion that is greater than 0.1%.
  • no flow means the perfusion criteria at which cuff deflation is initiated and is approximately less than 0.1 %.
  • baseline flow means the flow between the determination of "no flow” and qualified SPP value.
  • motion artifact means the absence of the characteristic patterns of perfusion return including caregiver, operator or environmental influences such as patient movement, voluntary and involuntary muscle contraction, unwanted noise, and caregiver and operator interference.
  • perfusion measurement is the calculation proportional to the AC/DC ratio of the signals acquired by a perfusion sensor measured at an applied cuff pressure.
  • perfusion percent means the quantitative measure of capillary blood flow as relative to that of maximally perfused tissue.
  • pressure cuff or "cuff” and similar references means a pneumatic cuff or any device that applies pressure to the site, e.g. from above, adjacent the site, circumferentially, etc.
  • P 0 is the perfusion measurement that is being evaluated or qualified for an SPP value.
  • return flow means the resumption of normal microcirculatory flow.
  • skin perfusion pressure value or "SPP value” represents the cuff pressure at which microcirculatory flow returns to the observation volume of tissue during the cuff deflation portion of the test.
  • the skin perfusion pressure monitoring system 10 broadly includes optical probe or sensor 12, pressure cuff 14, and skin perfusion pressure instrument 22 with display monitor 30.
  • the optical probe 12 is positioned underneath pressure cuff 14 proximate the skin of the patient's limb 18.
  • optical probe 12 may be positioned distal to cuff 14 or inside cuff bladder 14.
  • cuff 14 may include a transparent window to observe optical probe 12.
  • the skin perfusion pressure instrument inflates the pressure cuff 14 through tube 26.
  • the size of pressure cuff 14 may be varied depending on whether the limb involved is the arm, toe, leg, ankle, etc.
  • the observation volume of tissue 20 may be at the same location as the applied pressure, at a location near the applied pressure, or distal from the applied pressure, e.g. where flow is measured on the toe and pressure is applied at the ankle.
  • the skin perfusion instrument 22 is coupled to the optical probe 12 via a fiber optic cable 24, and the pressure cuff 14.
  • the optical probe 12 monitors microcirculatory flow within the observation volume of tissue 20.
  • Microcirculation detected within the observation volume of tissue 20 is expressed as a percent and displayed on the Y-axis of the perfusion pressure display instrument.
  • the percent value is shown as both a numeric value, typically from 0% to 10% and graphically is shown as a bar graph on the Y-axis of the instrument display 30.
  • the skin perfusion pressure instrument 22 also measures the pressure within the cuff 14 and displays the applied cuff pressure in millimeters of mercury on the X-axis of the display in descending uniform increments.
  • line 15 moves along the X-axis and shows the operator the cuff pressure that is currently being measured.
  • Optical probe 12 depicted in FIG. 1 includes at least a laser transmitter fiber 32 and at least one receiver photodiode 34.
  • the laser or photodiode, or both may be placed in probe 12 without a need for fiber optic- elements.
  • coherent light supplied from a solid state, or other laser device within the perfusion pressure display instrument 22 is conducted to the transmitter fiber 32 that is in contact with the patient's skin through the pressure cuff 14 bladder.
  • Photons emitted from the transmit fiber 32 are scattered by the patient's tissues.
  • a small portion (less than 5%) of the emitted photons is collected by the receiver fiber 34.
  • the spacing between the fibers and the optical apertures of the fibers establish the volume of tissue that is monitored.
  • a single transmitter fiber is used with a pair of receiver fibers.
  • the nominal fiber core diameter is on the order of 50 to 100 microns and is used to establish an observation volume of approximately one to two cubic millimeters.
  • a suitable optical probe is disclosed in U.S. Pat. No. 5,654,539 to Borgos, the entirety of which is hereby incorporated by reference.
  • microcirculatory flow returns to a given observation volume there are many ways to determine the point at which microcirculatory flow returns to a given observation volume. For example, visual observation such as the change in color of the observation site; ultra-sound; optical plethysmography, measurements of increases in temperature; sound, e.g. a microphone for pulsatile flow in the macrocirculation; metabolic indicators such as pCO 2 or lactate; and bioimpedance or pulse oximetry or both, each with a pulsatile measurement and a blood volume measurement.
  • visual observation such as the change in color of the observation site; ultra-sound; optical plethysmography, measurements of increases in temperature; sound, e.g. a microphone for pulsatile flow in the macrocirculation; metabolic indicators such as pCO 2 or lactate; and bioimpedance or pulse oximetry or both, each with a pulsatile measurement and a blood volume measurement.
  • Some back-scattered photons are frequency shifted by moving cells present in the microcirculation.
  • the collected photons are collected by the skin perfusion pressure instrument 22 via cable 24 where they impinge on a photodiode.
  • photons are impinging on the photodiode as a result of scattering off moving and stationary cells.
  • the photodiode voltage contains both frequency and power information.
  • the Doppler shifted frequency is related to cell velocity while the spectral power information is related to the volume of moving cells at that given frequency.
  • the DC signal component results from the total number of photons received by the receive fiber 34.
  • the AC signal component results from the mixing of frequency shifted photons with photons from stationary structures.
  • the perfusion measurement is proportional to the ratio of the AC signal to the DC signal, which is an indication of the volume of moving cells in the observation volume of tissue.
  • This type of measurement is commonly computed with both analog and digital signal processing. For example, it is common to convert the AC signal to an RMS equivalent through analog processing. It is these values that are presented to the A/D converter. The microprocessor then may square these digitized values prior to forming the ratio. The ratio value may be scaled by an empirically derived scaling factor that depends on the gain distribution throughout the signal processing paths.
  • the skin perfusion instrument 22 commences the cuff inflation process and the laser in optical prob ; e 12 is enabled.
  • the cuff 14 bladder is initially filled with a low pressure, such as 5 to lOmmHg, to ensure that the sensing probe is in contact with the patient's skin so that adequate perfusion can be detected and measured. If adequate perfusion cannot be measured, cuff inflation is aborted and the test does not proceed. If adequate perfusion can be measured, the pressure cuff 14 is inflated to the target pressure, near or at systolic and perfusion is measured.
  • FIG. 4 depicts the cuff deflation sequence.
  • cuff pressure starts to automatically deflate at a controlled rate.
  • a controlled rate of deflation provides reproducibility from measurement to measurement on the same patient and between patients. If the pressure is not dropping at the controlled rate, which may be caused by severe patient movement, cuff deflation is aborted and the test discontinued. If the pressure is dropping at the controlled rate, P 0 is analyzed for an SPP value. If all conditions for an SPP value are met, e.g. those discussed below, an SPP value is reported.
  • FIGS. 5A-D illustrate different stages of output data as depicted on the display monitor. Referring to FIG. 5A data being recorded during the testing procedure is displayed. Moving line 15 rises as pressure decreases. As can be seen, points representing adequate perfusion 35, no flow 36, baseline flow 37, SPP value 38, and the return of normal microcirculation 39 are depicted. FIG. 5A data being recorded during the testing procedure is displayed. Moving line 15 rises as pressure decreases. As can be seen, points representing adequate perfusion 35, no flow 36, baseline flow 37, SPP value 38, and the return of normal microcirculation 39 are depicted. FIG.
  • the skin perfusion pressure monitoring system in accordance with the present invention rejects motion artifact as not being a perfusion measurement and the test continues as seen by continuing line 15.
  • the skin perfusion pressure monitor in accordance with the present invention analyzes numerous different criteria for detecting and rejecting motion artifact in qualifying P 0 for a SPP value. If P 0 has been qualified as an SPP value, a bar graph is overlaid on line 15, as best seen in FIG. 5C, and the SPP value 38 is recorded. As those skilled in the art can appreciate, any graphical representation can be used to depict the perfusion measurement data set.
  • the skin perfusion pressure monitoring system 10 considers unique criteria in qualifying Po as an SPP value and in assessing whether motion artifact is present, Those skilled in the art can appreciate that many or few criteria may be considered. In addition, other criteria can be used other than those described below. For example, linear regression, slope intercept, differentiation, weighted average, and other known mathematical models may be used in addition to or in lieu of the criteria listed below. Whether the number of criteria considered is few or many, all criteria will be used to reject unwanted noise, environmental influences, or motion in combination with the qualification of a pressure at which microcirculatory flow returns to the observation or measurement volume.
  • P 0 must be within a valid range for the system to qualify an SPP value. If P 0 is not within a valid range, for example from approximately i mmHg to approximately 150mmHg, the system will not indicate that a particular P 0 is an SPP value.
  • step size i.e. perfusion increase large enough from the prior measurement
  • the instrument uses a perfusion sensitive tolerance that progressively adjusts sensitivity thresholds as perfusion returns. This allows the system to qualify SPP values over a wide dynamic range while being less sensitive to motion transients. For example, if perfusion is very low then the instrument allows for the detection and rejection of motion artifact due to its perfusion sensitive tolerance. Referring to Table 1 , preferred perfusion increases are noted. If the perfusion measurement is greater than 0.20% (i.e.
  • the applied cuff pressure is less than 100 mmHg a perfusion increase of from 10% to 50% and preferably 25% relative to the prior measurement, is necessary. If the perfusion measurement is greater than 0.20% (i.e. high perfusion measurement) and the applied cuff pressure is greater than or equal to 100 mmHg a perfusion increase of from 20% to about 80%, and preferably 40%, relative to prior measurement is necessary. If the perfusion measurement is between .15 to .20% (i.e. medium perfusion measurement) and the applied cuff pressure is any valid pressure a perfusion increase of from 25% to 100%, and preferably 50%, relative to the prior perfusion measurement is necessary. If the perfusion measurement is less than 0.15% (i.e. low perfusion measurement) and the applied cuff pressure is any valid pressure a perfusion increase of from 50% to 200%, and preferably 100%, relative to the prior perfusion measurement is necessary.
  • Another criterion is whether the perfusion measurement under evaluation, i.e. Po, is large enough, i.e. whether flow is above baseline.
  • the perfusion should be preferably from between .05 to .2% and more preferably at least 0.10% at point Po or no skin perfusion pressure will be recorded.
  • Another criterion determines whether the "next steps," i.e. those following point Po, are increasing or decreasing. Next steps must not be decreasing as this is not characteristic of a typical signature for returning microcirculatory flow to an observation volume with decreasing pressure.
  • This fourth criterion focuses on the duration of increasing perfusion change. As microcirculation flow returns it produces a perfusion signal that increases and holds in a signature pattern. Motion artifact produces a perfusion signal that has more oscillatory content, thereby having greater tendencies to decrease.
  • the number of next steps analyzed in determining whether next steps are increasing or decreasing is one.
  • the applied cuff pressure is in a medium range, for example from about 10 to 50mmHg and more preferably from about 15 to about 20mmHG, the number of next steps analyzed in determining whether next steps are increasing or decreasing is two.
  • applied cuff pressure is high, for example from about 40 to 120mmHg and preferably greater than 50mmHg but less than lOOmmHg, the number of next steps analyzed in determining whether next steps are increasing or decreasing is three.
  • pressure is very high, preferably from 80 to 150mmHg, and most preferably greater than lOOmmHg, the number of next steps analyzed in determining whether next steps are increasing or decreasing is five. The higher the number of next steps being analyzed, i.e. N, the more confidence that the system has qualified an SPP value.
  • Another criterion for detecting and rejecting motion artifact is the profile of perfusion change. Microcirculation produces a perfusion signal that increases step-wise while motion produces a perfusion signal that has more oscillatory content. Changes that do not follow a perfusion return signature are ignored.
  • the perfusion change profile criterion for detecting and rejecting motion artifact is whether the specified number of steps following Pi are at least at or above the perfusion value for Pi. These steps must not be decreasing. In other words, P 2 to PN must all be greater than P 1 . This criterion is especially effective in rejecting motion, as those signals are not long-lived. If all criteria are met the skin perfusion pressure system will qualify P 0 as the SPP value 38.
  • FIG. 5D depicts a model of what might be viewed if a patient has non- reactive hyperemia.
  • the skin perfusion pressure system will recognize such a pattern as not characteristic of a normal perfusion measurement and no SPP value will be generated. In such cases, the perfusion data is reported and the physician is left to determine the SPP value for that test.
  • the surface perfusion pressure system in accordance with the present invention and as previously described may include a sensor or probe placement device for providing assurance of reproducible data included as a kit or provided separately.
  • Sensor placement device 100 comprises a disposable sheath 130 sized to fit over an exemplary probe 120 used to measure microcirculatory blood flow.
  • sensor placement device 100 can be used to cover and secure various shapes and sizes of probes, electrodes and other monitoring devices.
  • Wings 140 In a first embodiment of a sensor placement device 100 two opposing wings 140 located at a proximal end 150 are provided. Wings 140 can be wrapped around a patient's appendage in order to secure probe 120 thereon. Wings 140 can be variably sized to accommodate different sized appendages.
  • Sensor placement device 100 also includes two opposing position indicators 160 located at proximal end 150. Position indicators 160 are configured to allow health care providers to mark the placement of the sensor placement device 100. If additional measurements are required, the sensor placement device 100 and probe 120 can be positioned in the same location on the surface of the tissue thereby assuring reproducible data.
  • Sensor placement device 100 includes a measuring guide 180 positioned on at least one side of sheath 130.
  • Measuring guide 180 is used to determine precise placement locations.
  • Measuring guide 180 can be sized according to and used in combination with perforations 200. For example, units of measurement can be started at proximal end 150 with units of measurement increasing toward distal end 170. In this manner, measuring guide 180 is useful for measuring position locations even after perforated sections closer to distal end 170 are removed.
  • Distal end 170 of sheath 130 includes probe securing means receiving openings 220 positioned on opposing sides of sheath 130.
  • Receiving openings 220 are sized and positioned to receive probe securing means 290.
  • Receiving openings 220 are positioned such that the distal end of sheath 130 is perfectly aligned with sheath stops 280 on opposing sides of the cable end of probe 120. In this manner, sensor placement device 100 is firmly secured to probe 120.
  • Receiving openings 220 depicted in FIGS. 6 and 7 are arcuate shaped. Those skilled in the art can appreciate that receiving openings can be sized or shaped to receive any size or shape of probe securing means 290.
  • distal end 170 of sheath 130 is adjacent cable clamp 240.
  • Cable clamp 240 is removable with an adhesive backing so that it can be separated from sensor placement device 100 and used to secure a cable 260 that extends between probe 120 and a monitoring system to a suitable surface.
  • the surface of sensor placement device 100 that contacts patient tissue may be treated with an adhesive coating.
  • the adhesive coating may include any repositionable, pressure sensitive adhesive that does not interrupt physiological parameter monitoring.
  • the adhesive coating is an inherently tacky, elastomeric, solvent-dispersible, solvent-insoluble pressure sensitive adhesive.
  • the adhesive coating is a monomer or polymer blend selected from the group consisting of alkyl acrylate, alkyl methacrylate ester, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, maleic acid, fumaric acid, sulfoethyl methacrylate, and ionic monomers such as sodium methacryate, ammonium acrylate, sodium acrylate, trimethylamine p-vinyl benzimide, 4,4,9-trimethyl-4- azonia-7-oxo-8-oxa-dec-9-ene-1-sulphonate, N,N-dimethyl-N-(.beta.- methacryloxyethyloxy-ethyl) ammonium propionate betaine, trimethylamine methacrylimide, and 1 , 1 -dimethyl- 1 -(2,3- dihydroxypropyl)amine methacrylimide.
  • the adhesive coating includes microspheres selected from the group consisting of acrylate, alkylacrylate and alkylacrylate ester monomers alone or in combination with vinyl monomers.
  • the adhesive coating can be covered with a removable paper film used to maintain the tackiness of the adhesive coating during storage, transportation and other non-use situations.
  • the size and shape of the sensor placement device 100 can be varied. Logos or other art designs can be embossed on any part of the sensor placement device 100.
  • the color of the sensor placement device 100 can also be a varied, including various patterns.
  • sensor placement devices 100 are dispensed in any convenient location such as operating rooms, intensive care units, clinic or hospital patient rooms, nursing areas, physician work stations and basically anywhere a probe 120 is used to monitor a physiological parameter.
  • a healthcare professional may remove a sensor placement device 100 from a dispenser device, box or other storage container and inserts a probe 120 into distal end 170 of sheath 130.
  • Openings 220 align with probe securing means 290.
  • Sheath 130 fits over probe 120 with distal end 170 of sheath adjacent sheath stops 280 as depicted in FIG. 7. If sensor placement device 100 is too long for the measurement site, sections of sensor placement device 100 can be removed by tearing them off at desired perforations 200. After sensor placement device 100 is positioned over probe 120, the removable paper film (not shown), if applicable, can be removed and measuring guide 180 can be used to precisely position sensor placement device 100 on a desired part of a patient's tissue. Wings 140 can be wrapped around a patient's appendage such as a toe or foot to secure sensor placement device 100 thereon.
  • Cable clamp 240 can be removed from distal end 170 of sheath 130 by tearing along perforations therebetween. Cable clamp 240 can then be used to secure cable 260 to a suitable support, such as a different part of patient's body, a hospital bed, etc.
  • cable clamp 240 can be detached and probe 120 can be removed from sensor placement device 100 without interrupting position of sensor placement device 100.
  • a different probe 120 can then be inserted into sensor placement device 100, again without interrupting position of sensor placement device 100.
  • probes 120 can be changed without requiring new sensor placement devices 100 or repositioning sensor placement device 100.
  • position indicators 160 can be marked such that a replacement sensor placement device 100 can be positioned in the same location as that of a previously placed sensor placement device 100. In this manner, interruptions to and errors in monitoring a physiological parameter can be minimized.
  • sensor placement device 100 prevents the transmission of infectious diseases while providing precise positioning, repositioning and securing of a probe to a patient's tissue.
  • sensor placement device 300 is shown.
  • the sensor placement device 300 depicted in Fig. 8 can be used for measurements taken on larger extremities without the need for adhesives and is intended to remain on the patient at the measurement site until all measurements have been taken.
  • Sensor placement device 300 may be constructed from a single sheet or multiple pieces.
  • Sensor placement device 300 comprises an elastic wrap including a laminate of non-woven material and elastic fibers placed lengthwise to provide for elasticity.
  • the fabric of sensor placement device 300 is a water-vapor permeable, non-woven polyester fabric containing longitudinal strands of polyester urethane, or elastane.
  • the fabric is coated with a self-adherent substance that gives the bandage the ability to stick to itself but not to skin or clothing.
  • the elastane strands impart a degree of elasticity to the bandage and the cohesive coating ensures that it does not become displaced once applied.
  • the fabric is marketed under the trade name CobanTM and is available from 3M Company, St. Paul, Minnesota.
  • Sensor placement device 300 is depicted as being made from multiple pieces but those skilled the art will appreciate that a single sheet of appropriate size may be used. Clear plastic window 310 having first and second edges 312, 314 is placed over and secured to one side of sheet. Window 310 remains open at edges 312, 314 so that probe (not shown) can be easily inserted and removed. Those skilled in the art will appreciate that only one edge of window 310 needs to remain open to accomplish the purpose of sensor placement. If multiple pieces are used, window 310 is bonded at various sites 316 by heat or chemical sealing over the elastic wrap.
  • the sensor placement device 300 is wrapped partially around a leg, for example, such that the window 310 is exposed.
  • the probe (not shown) is positioned in window 310 and then the sensor placement device is wrapped further around the extremity over the probe and window securing the probe in place while measurements are taken.
  • Fig. 6 can be positioned in window 310 to accomplish the measurement.

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  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Surgery (AREA)
  • General Health & Medical Sciences (AREA)
  • Biophysics (AREA)
  • Biomedical Technology (AREA)
  • Heart & Thoracic Surgery (AREA)
  • Medical Informatics (AREA)
  • Molecular Biology (AREA)
  • Physics & Mathematics (AREA)
  • Animal Behavior & Ethology (AREA)
  • Pathology (AREA)
  • Public Health (AREA)
  • Veterinary Medicine (AREA)
  • Physiology (AREA)
  • Signal Processing (AREA)
  • Hematology (AREA)
  • Cardiology (AREA)
  • Artificial Intelligence (AREA)
  • Computer Vision & Pattern Recognition (AREA)
  • Psychiatry (AREA)
  • Measuring Pulse, Heart Rate, Blood Pressure Or Blood Flow (AREA)

Abstract

Cette invention concerne un système de mesure automatique de perfusion cutanée, lequel système comprend un instrument conçu pour analyser automatiquement les mesures de perfusion afin d'identifier des artefacts dus aux mouvements et des valeurs SPP (pression de perfusion cutanée), et un dispositif de pose de capteur. L'instrument est conçu pour ignorer les artefacts dus aux mouvements. Les mesures de perfusion sont désignées en tant que valeurs SPP si plusieurs critères sont satisfaits. Les critères de valeurs SPP se rapportent à des facteurs parmi lesquels la pression au poignet, la perfusion, les pourcentages de modification de perfusion par rapport aux mesures de perfusion préalables et ultérieures. Le dispositif de pose de capteur permet de garantir l'obtention de données fiables lorsque plusieurs mesures sont souhaitées.
PCT/US2006/034116 2005-09-06 2006-08-30 Systeme de mesure automatique de la pression d'une perfusion cutanee WO2007030379A2 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
EP06790131A EP1933697A4 (fr) 2005-09-06 2006-08-30 Systeme de mesure automatique de la pression d'une perfusion cutanee
JP2008530108A JP5147700B2 (ja) 2005-09-06 2006-08-30 皮膚灌流圧の自動測定のためのシステム

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
USPCT/US2005/031505 2005-09-06
PCT/US2005/031505 WO2006031479A1 (fr) 2004-09-10 2005-09-06 Procede et instrument permettant de mesurer automatiquement la pression de perfusion de la peau
US11/468,203 2006-08-29

Publications (3)

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WO2007030379A2 true WO2007030379A2 (fr) 2007-03-15
WO2007030379A3 WO2007030379A3 (fr) 2007-05-31
WO2007030379A8 WO2007030379A8 (fr) 2008-01-24

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WO2008122973A2 (fr) * 2007-04-04 2008-10-16 Orsense Ltd. Procédé et appareil permettant de renforcer et d'améliorer la qualité de signaux de mesure d'analyte
WO2009141758A1 (fr) * 2008-05-19 2009-11-26 Koninklijke Philips Electronics N.V. Dispositif régulateur de perfusion
CN106175789A (zh) * 2015-05-06 2016-12-07 置富存储科技(深圳)有限公司 穿戴式生理状态测量装置
US9814401B2 (en) 2012-07-06 2017-11-14 Covidien Lp Angiosome-based perfusion monitoring system
WO2018162728A3 (fr) * 2017-03-09 2018-10-18 Smith & Nephew Plc Dispositif, appareil et procédé de détermination de pression de perfusion cutanée
US10288590B2 (en) 2013-10-08 2019-05-14 Smith & Nephew Plc PH indicator device and formulation
US11076997B2 (en) 2017-07-25 2021-08-03 Smith & Nephew Plc Restriction of sensor-monitored region for sensor-enabled wound dressings
US11324424B2 (en) 2017-03-09 2022-05-10 Smith & Nephew Plc Apparatus and method for imaging blood in a target region of tissue
US11395872B2 (en) 2008-01-08 2022-07-26 Smith & Nephew, Inc. Sustained variable negative pressure wound treatment and method of controlling same
US11559438B2 (en) 2017-11-15 2023-01-24 Smith & Nephew Plc Integrated sensor enabled wound monitoring and/or therapy dressings and systems
US11596553B2 (en) 2017-09-27 2023-03-07 Smith & Nephew Plc Ph sensing for sensor enabled negative pressure wound monitoring and therapy apparatuses
US11633153B2 (en) 2017-06-23 2023-04-25 Smith & Nephew Plc Positioning of sensors for sensor enabled wound monitoring or therapy
US11633147B2 (en) 2017-09-10 2023-04-25 Smith & Nephew Plc Sensor enabled wound therapy dressings and systems implementing cybersecurity
US11638664B2 (en) 2017-07-25 2023-05-02 Smith & Nephew Plc Biocompatible encapsulation and component stress relief for sensor enabled negative pressure wound therapy dressings
US11690570B2 (en) 2017-03-09 2023-07-04 Smith & Nephew Plc Wound dressing, patch member and method of sensing one or more wound parameters
US11717447B2 (en) 2016-05-13 2023-08-08 Smith & Nephew Plc Sensor enabled wound monitoring and therapy apparatus
US11744741B2 (en) 2008-03-12 2023-09-05 Smith & Nephew, Inc. Negative pressure dressing and method of using same
US11759144B2 (en) 2017-09-10 2023-09-19 Smith & Nephew Plc Systems and methods for inspection of encapsulation and components in sensor equipped wound dressings
US11791030B2 (en) 2017-05-15 2023-10-17 Smith & Nephew Plc Wound analysis device and method
US11839464B2 (en) 2017-09-28 2023-12-12 Smith & Nephew, Plc Neurostimulation and monitoring using sensor enabled wound monitoring and therapy apparatus
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US11957545B2 (en) 2017-09-26 2024-04-16 Smith & Nephew Plc Sensor positioning and optical sensing for sensor enabled wound therapy dressings and systems
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US12011942B2 (en) 2019-03-18 2024-06-18 Smith & Nephew Plc Rules for sensor integrated substrates
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Cited By (34)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2008122973A2 (fr) * 2007-04-04 2008-10-16 Orsense Ltd. Procédé et appareil permettant de renforcer et d'améliorer la qualité de signaux de mesure d'analyte
WO2008122973A3 (fr) * 2007-04-04 2009-03-12 Orsense Ltd Procédé et appareil permettant de renforcer et d'améliorer la qualité de signaux de mesure d'analyte
US11395872B2 (en) 2008-01-08 2022-07-26 Smith & Nephew, Inc. Sustained variable negative pressure wound treatment and method of controlling same
US11744741B2 (en) 2008-03-12 2023-09-05 Smith & Nephew, Inc. Negative pressure dressing and method of using same
WO2009141758A1 (fr) * 2008-05-19 2009-11-26 Koninklijke Philips Electronics N.V. Dispositif régulateur de perfusion
US9814401B2 (en) 2012-07-06 2017-11-14 Covidien Lp Angiosome-based perfusion monitoring system
US10383533B2 (en) 2012-07-06 2019-08-20 Covidien Lp Angiosome-based perfusion monitoring system
US10288590B2 (en) 2013-10-08 2019-05-14 Smith & Nephew Plc PH indicator device and formulation
CN106175789A (zh) * 2015-05-06 2016-12-07 置富存储科技(深圳)有限公司 穿戴式生理状态测量装置
US11717447B2 (en) 2016-05-13 2023-08-08 Smith & Nephew Plc Sensor enabled wound monitoring and therapy apparatus
WO2018162728A3 (fr) * 2017-03-09 2018-10-18 Smith & Nephew Plc Dispositif, appareil et procédé de détermination de pression de perfusion cutanée
US11324424B2 (en) 2017-03-09 2022-05-10 Smith & Nephew Plc Apparatus and method for imaging blood in a target region of tissue
US11690570B2 (en) 2017-03-09 2023-07-04 Smith & Nephew Plc Wound dressing, patch member and method of sensing one or more wound parameters
US11883262B2 (en) 2017-04-11 2024-01-30 Smith & Nephew Plc Component positioning and stress relief for sensor enabled wound dressings
US12033738B2 (en) 2017-05-15 2024-07-09 Smith & Nephew Plc Negative pressure wound therapy system using eulerian video magnification
US11791030B2 (en) 2017-05-15 2023-10-17 Smith & Nephew Plc Wound analysis device and method
US12102447B2 (en) 2017-06-23 2024-10-01 Smith & Nephew Plc Positioning of sensors for sensor enabled wound monitoring or therapy
US11633153B2 (en) 2017-06-23 2023-04-25 Smith & Nephew Plc Positioning of sensors for sensor enabled wound monitoring or therapy
US11076997B2 (en) 2017-07-25 2021-08-03 Smith & Nephew Plc Restriction of sensor-monitored region for sensor-enabled wound dressings
US11638664B2 (en) 2017-07-25 2023-05-02 Smith & Nephew Plc Biocompatible encapsulation and component stress relief for sensor enabled negative pressure wound therapy dressings
US11925735B2 (en) 2017-08-10 2024-03-12 Smith & Nephew Plc Positioning of sensors for sensor enabled wound monitoring or therapy
US11633147B2 (en) 2017-09-10 2023-04-25 Smith & Nephew Plc Sensor enabled wound therapy dressings and systems implementing cybersecurity
US11931165B2 (en) 2017-09-10 2024-03-19 Smith & Nephew Plc Electrostatic discharge protection for sensors in wound therapy
US11759144B2 (en) 2017-09-10 2023-09-19 Smith & Nephew Plc Systems and methods for inspection of encapsulation and components in sensor equipped wound dressings
US12114994B2 (en) 2017-09-10 2024-10-15 Smith & Nephew Plc Sensor enabled wound therapy dressings and systems implementing cybersecurity
US11957545B2 (en) 2017-09-26 2024-04-16 Smith & Nephew Plc Sensor positioning and optical sensing for sensor enabled wound therapy dressings and systems
US11596553B2 (en) 2017-09-27 2023-03-07 Smith & Nephew Plc Ph sensing for sensor enabled negative pressure wound monitoring and therapy apparatuses
US12097092B2 (en) 2017-09-27 2024-09-24 Smith & Nephew Plc pH sensing for sensor enabled negative pressure wound monitoring and therapy apparatuses
US11839464B2 (en) 2017-09-28 2023-12-12 Smith & Nephew, Plc Neurostimulation and monitoring using sensor enabled wound monitoring and therapy apparatus
US11559438B2 (en) 2017-11-15 2023-01-24 Smith & Nephew Plc Integrated sensor enabled wound monitoring and/or therapy dressings and systems
US11944418B2 (en) 2018-09-12 2024-04-02 Smith & Nephew Plc Device, apparatus and method of determining skin perfusion pressure
US11969538B2 (en) 2018-12-21 2024-04-30 T.J.Smith And Nephew, Limited Wound therapy systems and methods with multiple power sources
US12011942B2 (en) 2019-03-18 2024-06-18 Smith & Nephew Plc Rules for sensor integrated substrates
US12016994B2 (en) 2019-10-07 2024-06-25 Smith & Nephew Plc Sensor enabled negative pressure wound monitoring apparatus with different impedances inks

Also Published As

Publication number Publication date
EP1933697A4 (fr) 2011-05-25
WO2007030379A8 (fr) 2008-01-24
WO2007030379A3 (fr) 2007-05-31
EP1933697A2 (fr) 2008-06-25

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