WO2009053920A1 - Contrôle du degré d'hydratation du corps humain - Google Patents

Contrôle du degré d'hydratation du corps humain Download PDF

Info

Publication number
WO2009053920A1
WO2009053920A1 PCT/IB2008/054371 IB2008054371W WO2009053920A1 WO 2009053920 A1 WO2009053920 A1 WO 2009053920A1 IB 2008054371 W IB2008054371 W IB 2008054371W WO 2009053920 A1 WO2009053920 A1 WO 2009053920A1
Authority
WO
WIPO (PCT)
Prior art keywords
blood
light
blood vessel
occlusion
measuring
Prior art date
Application number
PCT/IB2008/054371
Other languages
English (en)
Inventor
Natallia E. Uzunbajakava
Aleksey Kharin
Markus Laubscher
Runze Wu
Golo Von Basum
Thomas Vollmer
Cristian N. Presura
Original Assignee
Koninklijke Philips Electronics N.V.
Philips International Property And Standards Gmbh
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
Application filed by Koninklijke Philips Electronics N.V., Philips International Property And Standards Gmbh filed Critical Koninklijke Philips Electronics N.V.
Publication of WO2009053920A1 publication Critical patent/WO2009053920A1/fr

Links

Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/0059—Measuring for diagnostic purposes; Identification of persons using light, e.g. diagnosis by transillumination, diascopy, fluorescence
    • 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
    • A61B5/48—Other medical applications
    • A61B5/4869—Determining body composition
    • A61B5/4875—Hydration status, fluid retention of the body
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/0002—Remote monitoring of patients using telemetry, e.g. transmission of vital signals via a communication network
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/44—Detecting, measuring or recording for evaluating the integumentary system, e.g. skin, hair or nails
    • A61B5/441—Skin evaluation, e.g. for skin disorder diagnosis

Definitions

  • the invention relates to the field of monitoring the degree of hydration of the human body based on measuring the time for refilling an occluded blood vessel with blood, especially by measuring vein refilling time (VRT) and/or capillary refilling time (CRT).
  • VRT vein refilling time
  • CRT capillary refilling time
  • Water accounts for up to 70 % of the mass of the human body and is essential for maintaining normal physiological functions. It is well known that dehydration, i.e. water loss, impares normal physiology. Physiological responses caused by dehydration depend on the amount of water loss. For example, water loss corresponding to 2 % decrease in body weight leads to reduced exercise performance and alertness. Further dehydration can lead to serious consequences, such as tissue damage, heart attack, stroke and even death.
  • Dehydration is encountered in a wide range of population from newborns to the elderly. Further, dehydration is particularly common under certain environmental and clinical conditions such as hot weather, vomiting, and diarrhea. There has been a steady increase in the number of hospitalizations due to dehydration in the past decade with substantial mortality occurred especially for elderly persons and children, respectively. Early detection of dehydration followed by proper care can reduce these numbers significantly because of the preventable and reversable nature of dehydration.
  • dehydration detection relies on laboratory tests or appearance of certain symptoms, e.g. thirst or a dry mouth.
  • symptomatic dehydration detection is inaccurate, subjective and unspecific and, thus, does not allow for dehydration quantification, i.e. determination of the degree of hydration/dehydration of the human body.
  • symptomatic dehydration detection usually detects a relatively late stage of dehydration.
  • laboratory tests performed by medical professionals are invasive and cost- and time-consuming.
  • vein refilling is typically performed for the elderly as well as for infants. In the case of the elderly, generally, small veins of the foot are used, while in the case of children, often, small capillaries below the fingernails are used. Visual observation of vein refilling, however, does not allow for accurate and in-time dehydration detection.
  • dehydration can be classified in four categories: (i) blood returns instantly, i.e. vein is filled, (ii) direction of blood flow is easily observed, i.e. vein is still filled, (iii) blood returns slowly, i.e. vein requires about 3 s to refill, and (iv) vein remains collapsed after release of occlusion.
  • a diagnostic medical instrument is described that is used in a capillary refilling time test procedure in which a skin area which overlies blood- filled capillaries, which normally display a pink color, is depressed to expel blood from the capillaries. When the pressure is released, blood is permitted to flow back into the capillaries, and, thus, the skin looses its white colour and regains its pink colour again.
  • the instrument includes a colour sensor trained on the skin area and responsive to light reflected therefrom. By measuring the time necessary for the skin to regain its pink colour, capillary refilling time is measured in order to determine the degree of hydration of the patient.
  • measurements with this instrument are not reliable and secure, especially when used for people with a darker skin type.
  • this is object is addressed by a method for monitoring the degree of hydration of the human body based on measuring the time for refilling an occluded blood vessel with blood, the method comprising the following steps: irradiating tissue comprising the blood vessel with linearly polarized light of at least one predefined wavelength; collecting the part of the reflected light which is orthogonally polarized with respect to the irradiated light as an image; occluding the blood vessel, in order to remove the blood from the blood vessel; release of occlusion of the blood vessel in order to allow the blood to refill the blood vessel; analyzing the image with respect to the flow of blood cells; measuring the time necessary for regaining a predefined flow of blood cells after release of occlusion.
  • orthogonal polarization spectral imaging is used in order to monitor blood flow back in the blood vessel after release of occlusion.
  • OPSI orthogonal polarization spectral imaging
  • the OPSI principle is based on the idea of irradiating linearly polarized light on tissue, while only that component of the light propagating back from the tissue is detected which is orthogonally polarized with respect to the incident light.
  • the light reflected from the surface of the tissue shows the same polarization direction as the incident light, while the light coming back from the deeper tissue layers which contain blood vessels has a different polarization.
  • OPSI allows to detect blood flow in blood vessels below the surface of the tissue.
  • the method according to the first aspect of the invention allows for an image, i.e. a two- dimensional representation, of blood vessels located below the surface, i.e. inside the tissue, and, thus, for blood flow detection in deeper lying blood vessels.
  • the blood vessels examined by this method can generally be of any type, especially the blood vessels can be veins or capillaries.
  • the time measured can especially be vein refilling time or capillary refilling time, respectively. Further, it should be noted that the order of the steps as explained above does not mean that these steps are carried out consecutively.
  • the tissue is irradiated with light and reflected light is collected for analyzing the blood cell flow and, thus, for determining the refilling time, at least during refilling of the blood vessel, i.e. starting with release of occlusion and ending with total refill.
  • irradiation and collection of light is performed continuously, it is also possible to irradiate and/or collect the light only at discrete times. Concerning the analysis of the image with respect to the flowing blood cells, in general, this can be done continuously, too. However, it is preferred to perform this analysis at a predefined rate, like at an image rate of a video camera used for capturing images of the blood vessels and the blood cells flowing therein.
  • the irradiated linearly polarized light comprises at least two different predefined wavelengths, from the collected part of the reflected light which is orthogonally polarized with respect to the irradiated light two different images for the two different wavelengths are generated, respectively, the images are subtracted from each other in order to generate a differential image; and the differential image is analyzed with respect to the flow of blood cells.
  • two different wavelengths provides for the possibility to use such wavelengths, respectively, which are differently absorbed by blood vessels. Accordingly, an increase of contrast can be achieved and background signals coming from surrounding tissue can eliminated to a large extent.
  • a device for monitoring the degree of hydration of the human body based on measuring the time for refilling an occluded blood vessel with blood comprising: a light source for irradiating tissue comprising the blood vessel with linearly polarized light of at least one predefined wavelength; a light detector for collecting the part of the reflected light which is orthogonally polarized with respect to the irradiated light as an image; an occlusion means for occluding the blood vessel, in order to remove the blood from the blood vessel; an analyzer for analyzing the image with respect to the flow of blood cells; and a measuring unit for measuring the time necessary for regaining a predefined flow of blood cells after release of occlusion.
  • This device is preferably used with a method according to the first aspect of the invention described above. Since the light detector collects reflected light as an image, a two-dimensional light detector like a camera is used.
  • a method for monitoring the degree of hydration of the human body based on measuring the time for refilling an occluded blood vessel with blood comprising the following steps: irradiating tissue comprising the blood vessel with light of at least one predefined wavelength; collecting a reflected part of the light in order to generate a magnified image of the blood cells flowing through the blood vessel; occluding the blood vessel, in order to remove the blood from the blood vessel; release of occlusion of the blood vessel in order to allow the blood to refill the blood vessel; analyzing the image with respect to the flow of blood cells; measuring the time necessary for regaining a predefined flow of blood cells after release of occlusion.
  • the method according to the second aspect of the invention uses a microscopy based method with a magnified image of a blood vessel in order to monitor the blood flow through the blood vessel.
  • the method according to the second aspect of the invention uses a magnifying imaging system in order to generate a magnified image of the blood cells flowing through the blood vessel. Using this magnified image, the flow rate of the blood cells and, thus, refilling time can be determined.
  • analyzing the image with respect to the flow of blood cells comprises the detection of the number of blood cells flowing through the blood vessel per time unit and/or the detection of the temporal change of the number of blood cells flowing through the blood vessel per time unit.
  • a device for monitoring the degree of hydration of the human body based on measuring the time for refilling an occluded blood vessel with blood comprising: a light source for irradiating the tissue comprising the blood vessel with light of at least one predefined wavelength; a microscope imaging system for collecting a reflected part of the light in order to generate a magnified image of the blood cells flowing through the blood vessel; a light detector for collecting the magnified image of the blood cells flowing through the blood vessel; an occlusion means for occluding the blood vessel, in order to remove the blood from the blood vessel; an analyzer for analyzing the image with respect to the flow of blood cells; a measuring unit for measuring the time necessary for regaining a predefined flow of blood cells after release of occlusion.
  • This device is preferably used with a method according to the second aspect of the invention described above.
  • a method for monitoring the degree of hydration of the human body based on measuring the time for refilling an occluded blood vessel with blood comprising the following steps: irradiating tissue comprising the blood vessel with light of at least one predefined wavelength, the wavelength relating to an absorption band of a main component ofblood; collecting the reflected light or the light which is transmitted through the tissue, respectively; occluding the blood vessel, in order to remove the blood from the blood vessel; release of occlusion of the blood vessel in order to allow the blood to refill the blood vessel; determining the intensity of the reflected light or the transmitted light, respectively; measuring the time necessary for regaining a predefined intensity of the reflected light or the transmitted light, respectively, after release of occlusion.
  • diffuse reflectance or diffuse transmittance is used in order to monitor the regaining flow ofblood cells in the blood vessel under observation by the intensity of the reflected part or the transmitted part of the light, respectively. This means that a one-dimensional signal is acquired.
  • the wavelength of the incident light relates to an absorption band of a main component ofblood.
  • concentration of the main component of blood used is sufficient to provide for a good S/N-ratio.
  • different main components ofblood can be used.
  • haemoglobin is used as main component of blood and, thus, the irradiated wavelength relates to an absorption band of haemoglobin.
  • a device for monitoring the degree of hydration of the human body based on measuring the time for refilling an occluded blood vessel with blood comprising: a light source for irradiating tissue comprising the blood vessel with light of at least one predefined wavelength, the wavelength relating to an absorption band of a main component of blood; a light detector for collecting the reflected light or the light transmitted through the tissue, respectively; an occlusion means for occluding the blood vessel, in order to remove the blood from the blood vessel; an analyzer for determining the intensity of the reflected light or the transmitted light, respectively; and a measuring unit for measuring the time necessary for regaining a predefined intensity of the reflected light or the transmitted light, respectively, after release of occlusion.
  • This device is preferably used with a method according to the third aspect of the invention described above.
  • different wavelengths can be used for the incident light.
  • green light preferably at or around 450 nm
  • red light preferably at or around 660 nm
  • the contrast of a differential image is increased since these different wavelengths are differently absorbed by blood and tissue material, respectively. Accordingly, disturbing background signals can be eliminated efficiently.
  • NIR light near- infrared light
  • NIR light can provide for a greater penetration depth, thus, leading to a better S/N-ratio for deeper lying blood vessels.
  • light with different wavelengths can be used, too.
  • green light especially at or around 450 nm
  • NIR light especially in the range from 760 - 900 nm
  • NIR light is especially preferred because of its great penetration depth in human tissue.
  • the methods and devices according to the invention allow for different methods for determining the degree of hydration of the human body.
  • the time necessary for regaining a predefined flow of blood cells after release of occlusion is compared with predefined times in order to determine the degree of hydration of the human body.
  • the measured times for regaining a predefined flow of blood cells in the blood vessel under observation is compared to expected values which relate to different degrees of hydration, e.g. such degrees of hydration as described with respect to the background of the invention above.
  • a predefined absolute value of blood flow can be used.
  • the predefined flow of blood cells is a constant flow of blood cells. This embodiment makes it easy to reliably detect a total refill of the blood vessel under consideration since absolute values of blood cell flow can vary from person to person and even for one person, e.g. depending on posture and mental stress.
  • the predefined flow of blood cells has been defined by analyzing the flow of blood cells before occlusion of the blood vessel as an absolute value. According to this preferred embodiment of the invention it is possible to determine the time for refilling the blood vessel after release of occlusion by simply determining that the original flow of blood cells has been regained.
  • different types of occlusion means can be used. In general, an occlusion means for use with a device according to the first, second or third aspect of the invention, respectively, can be opaque.
  • the occlusion means is transparent for the irradiated and/or reflected light, respectively. This provides for the possibility to radiate incident or reflected light through the occlusion means, e.g. in order to provide for a simple beam structure and, thus, for an easy design of the device.
  • the occlusion means can also comprise a beam splitter. This eliminates the need for a separate beam splitter in the case that irradiated light and reflected light is guided through the occlusion means in different directions, respectively.
  • the occlusion means can be provided as an active or a passive unit, respectively.
  • the occlusion means comprises an actuator that actively applies a force on the tissue that comprises the blood vessel.
  • a simple actuator according to such a preferred embodiment of the invention can be made of a bloc of solid material which, when pressed into the tissue, removes the blood from the blood vessel.
  • the actuator is provided in a cuff, which can be fixed around a limb of the human body, e.g. a foot.
  • a cuff which can be fixed around a limb of the human body, e.g. a foot.
  • designs of according devices are possible which are suited for self-monitoring consumer devices intended for home use, thus eliminating the need for specially educated medical staff.
  • the actuator comprises at least one roller wheel that can be rolled over the tissue comprising the blood vessel.
  • this type of actuator comprises two roller wheels which are placed on the skin in the proximity of the blood vessel under consideration. While one wheel stays fixed at the initial position, the other wheel moves along the vein towards the heart, pushes the blood away from the blood vessel, and then stays fixed at another position. At the moment the two wheels are released, the signal of refilling of the blood vessel is taken and the refilling time required is estimated.
  • occlusion means is the combination of two actuators shifted for some distance from each other.
  • One of the actuators is further away from the heart than the other.
  • the actuator further away occludes first, then, the second actor occludes at a near heart side with some time delay. During this time delay blood can leave the blood vessel. Then, after release of both actuators the measurement is taken in the middle of the actuators.
  • the occlusion means is provided as a passive unit which provides a counterpart for pressing with a part of the human body.
  • the occlusion means comprises a pressing plate which can be pressed with the tip of a finger of the patient. This way, occlusion of a blood vessel under consideration can be achieved without actively providing a pressing force.
  • the occlusion means comprises a force sensor for sensing the force applied.
  • the occlusion means as a passive unit, this way it can be estimated if a sufficient force by pressing with the part of the human body is applied in order to achieve the required occlusion of the blood vessel.
  • Fig. 1 is a diagrammatic view of vein refilling time monitoring using the OPSI method on a foot vein according to a first embodiment of the invention
  • Fig. 2 is a diagrammatic view of capillary refilling time monitoring using the OPSI method on a finger nail according to a second embodiment of the invention
  • Fig. 3 is a diagrammatic view of vein/capillary refilling time monitoring using diffuse transmittance on a fingernail according to a third embodiment of the invention
  • Fig. 4 is a diagrammatic view of vein/capillary refilling time monitoring using diffuse reflectance on a fingernail according to a forth embodiment of the invention
  • Fig. 5 is a diagrammatic view of a microscopy imaging based capillary refilling time meter according to a fifth embodiment of the invention
  • Fig. 6 is a diagrammatic view of a microscopy imaging based capillary refilling time meter according to a sixth embodiment of the invention.
  • Fig. 7 is a diagrammatic view of an imaging device for use with the microscopy imaging devices according to the fifth and sixth embodiment of the invention, respectively.
  • FIG. 1 a diagrammatic view of a device according to a first embodiment of the invention can be seen.
  • a device for monitoring the degree of hydration of the human body based on measuring the time for refilling an occluded vein 1 of a foot 2 with blood is shown.
  • This device for vein refilling time monitoring uses the OPSI method which means that tissue of the foot 2 comprising the vein 1 is irradiated with linearly polarized light of one predefined wavelength, and the part of the reflected light which is orthogonally polarized with respect to the irradiated light is collected as an image.
  • the device comprises a cuff 3 which can be fixed around the foot 2 and which comprises a light source 4 for irradiating the tissue with linearly polarized green light of 450 nm.
  • the light emitted from the light source 4 is sent through a beam splitter 5 to an occlusion means 6 which is formed by a transparent actuator.
  • the occlusion means 6 the light emitted from the light source 4 is directed onto the tissue comprising the vein 1 of the foot 2.
  • a light detector 7 is provided that collects that part of the reflected light which is orthogonally polarized with respect to the irradiated light as an image. For that, the reflected light is lead through the occlusion means 6 to the beam splitter 5 where the beam of the reflected light is directed onto the light detector 7. For selectively detecting only that part of the reflected light which is orthogonally polarized with respect to the incident light, the beam splitter 5 is a polarizing beam splitter so that only linearly polarized light is directed onto the light detector 7.
  • the light detector 7 is provided as a video camera for receiving an image of the vein 1 under consideration.
  • the device for monitoring vein refilling time is operated using a rechargeable accumulator 8 as a power supply which is provided within the cuff 3.
  • Image data is sent wirelessly from light detector 7 to an analyzer 9.
  • the image signal from light detector 7 is processed with respect to the flow of blood cells. It is determined how the flow of blood cells per time unit changes in order to determine the necessary time for refilling the vein 1 after release of occlusion by the occlusion means 6.
  • the analyzer 9 is combined with a measuring unit 10 in a desktop housing 11 which also comprises a display 17 for indicating the determined degree of hydration.
  • the analyzer 9 serves for analyzing the image with respect to the flow of blood cells, wherein the measuring unit 10 serves for measuring the time necessary for regaining a predefined flow of blood cells after release of occlusion.
  • the regain in blood flow can be estimated e.g. as difference in contrast in the images obtained before and after occlusion, respectively.
  • Vein refilling time monitoring using the OPSI method with the device according to the first embodiment of the invention shown in Fig. 1 is performed as follows: By pressing the actuator 6 onto the vein 1 , vein 1 is occluded.
  • the tissue containing vein 1 is irradiated with linearly polarized light, and the reflected part of the light which is orthogonally polarized with respect to the incident light is detected in order to generate an image of the vein 1 and the the blood cell flow therethrough.
  • the vein refilling time and, thus, the degree of hydration is measured and displayed.
  • Fig. 2 a diagrammatic view of a device according to a second embodiment of the invention can be seen.
  • This device according to the second embodiment of the invention serves for capillary refilling time monitoring using the OPSI method on a fingernail.
  • the device comprises a two-part actuator 12 that serves as a "clamp" for a fingertip 13.
  • the two-part actuator 12 comprises a lower actuator part 14 and an upper actuator part 15.
  • the lower actuator part 14 is movable relative to the upper actuator part 15. Accordingly, the fingertip 13 can be "clamped” in the two-part actuator in order to receive occlusion of the capillaries.
  • the upper actuator part 15 is transparent which allows light coming from a light source 4 to irradiate the tissue with its capillaries under the fingernail 16. According to the second preferred embodiment of the invention, green light with a wavelength of 450 nm together with red light at a wavelength of 660 nm is irradiated.
  • a polarizing beam splitter 5 With the help of a polarizing beam splitter 5 only that part of the green light and the red light, respectively, is detected by a light detector 7 which has a polarization direction which is orthogonal to the polarization direction of the incident light. In case more than one wavelength is used for illumination, multiple light detectors are used, i.e. one for each wavelength, in order to generate a respective signal for each wavelength.
  • the image signals are sent from light detector 7 wirelessly to a desktop housing 11 comprising an analyzer 9 and a measuring unit 10.
  • the "red” and “green” pictures are subtracted from each other leading to a differential image which shows an enhanced contrast of the image of the capillaries in which flow of the blood cells is to be determined.
  • Operation of the device according to the second embodiment of the invention is similar to operation of the device according to the first embodiment of the invention: After release of occlusion the time for regaining original blood cell flow is measured in order to determine capillary refilling time and thus the degree of hydration.
  • FIG. 1 and 2 can include at least one focusing element, such as a lens to form an image of the selected tissue area containing blood vessels on the detector.
  • An additional lens or a combination of lenses can be used to illuminate a sufficiently large skin area, where blood vessels are located.
  • FIG. 3 a diagrammatic view of vein/capillary refilling time monitoring using diffuse transmittance on a fingernail according to a third embodiment of the invention can be seen.
  • This device comprises a light source for emitting NIR light with a predefined wavelength in the range between 760 and 900 nm.
  • This incident light is transmitted through a transparent actuator which can "clamp" a fingertip together with a light detector 7 in order to achieve occlusion of veins and/or capillaries.
  • the diffuse transmittance signal received by light detector 7 is determined and, thus, vein/capillary refilling time is measured via the temporal change of the intensity of the transmitted light.
  • a diagrammatic view of vein/capillary refilling time monitoring using diffuse reflectance on a fingernail can be seen.
  • a two-part actuator 12 is provided which is formed by an upper actuator part 15 which is transparent and a lower actuator part 14 which can be moved relative to the upper actuator part 15 in order to "clamp" the fingertip 13 in the two-part actuator 12 for achieving occlusion.
  • diffuse reflectance is measured. This means that that light reflected back from the irradiated tissue material is collected by a light detector 7.
  • the diffuse reflectance signal received by light detector 7 is determined and, thus, vein/capillary refilling time is measured via the temporal change of the intensity of the reflected light.
  • Fig. 5 a fifth embodiment of the invention is shown which comprises an imaging device 18 which is described in greater detail with reference to Fig. 7, and a passive occlusion means 19.
  • the occlusion means 19 comprises a transparent pressing plate 20 and a force sensor 21 for sensing the force applied on the pressing plate 20. Occlusion of capillaries in the fingertip 13 is achieved according to the fifth preferred embodiment of the invention by pressing the fingertip 13 onto the pressing plate 20 until the force sensor 21 senses a sufficient force for occluding the capillaries in the fingertip 13. After release of occlusion refilling of the capillaries is imaged by imaging device 18.
  • Imaging device 18 is shown in greater detail in Fig. 7. There, it can be seen that imaging device 18 comprises a microscope imaging system 22 for generating a magnified image of the capillaries in the fingertip 13.
  • the fingertip 13 which is pressed on the transparent pressing plate 20 is irradiated with incident light of 450 nm by a light source 4 formed by a LED.
  • the pressing plate 20 is provided within an oil container 23 filled with such an amount of oil 24 that provides for an essentially undisturbed optical path between the pressing plate 20 and the fingertip 13.
  • a magnified image of the capillaries of the fingertip 13 is achieved with the aid of the microscope imaging system 22 and a light detector 7 which is formed by a video camera.
  • the image signal received by the light detector 7 is transmitted to an analyzer 9 and a measuring unit 10 for further processing, especially for analyzing the image with respect to blood cell flow within the capillaries in order to determine refilling time after release of occlusion by pressing against the transparent pressing plate 20.
  • FIG. 6 a diagrammatic view of a microscopy imaging based capillary refilling time meter according to a sixth embodiment of the invention can be seen.
  • General functions of this device are similar to the ones described with respect to the device according to the fifth embodiment of the invention.
  • an active occlusion means 19 is provided which acts as a "clamp" actuator similar to the one described with respect to the third and forth embodiment of the invention.
  • the preferred wavelengths for use with the methods and devices described herein are:: 576 nm, 556 nm, 540 nm, 415 nm which relate to oxyhemoglobin; 928 nm, 756 nm, 556 nm, 432 nm which relate to deoxyhemoglobin; and 796 nm, 500 nm, 674 nm as reference wavelengths.
  • These wavelengths correspond to the maxima of the absorption bands of hemoglobin, and in particular, oxy- and deoxyhemoglobin as well as to iso-points as well as minima of absorption. The latter can be used as reference to acquire tissue signal nonspecific with respect to blood vessels, which is later subtracted from the specific signal.
  • All the embodiments can include additional optical components, such as focusing elements, e.g., lenses, filters for selecting a particular wavelength, polarizing elements for selecting a preferential polarization, matching fluid to match the refractive index of the illumination optics with the one of the skin. Additionally, in case multiple wavelengths are used at least one dichroic beamsplitter can be used to selectively reflect/transmit the wavelength of interest.
  • Light sources may include broadband halogen lamps, LEDs, or lasers. While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive; the invention is not limited to the disclosed embodiments.

Landscapes

  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Medical Informatics (AREA)
  • Biophysics (AREA)
  • Pathology (AREA)
  • Engineering & Computer Science (AREA)
  • Biomedical Technology (AREA)
  • Heart & Thoracic Surgery (AREA)
  • Physics & Mathematics (AREA)
  • Molecular Biology (AREA)
  • Surgery (AREA)
  • Animal Behavior & Ethology (AREA)
  • General Health & Medical Sciences (AREA)
  • Public Health (AREA)
  • Veterinary Medicine (AREA)
  • Hematology (AREA)
  • Cardiology (AREA)
  • Physiology (AREA)
  • Investigating Or Analysing Materials By Optical Means (AREA)

Abstract

L'invention concerne le domaine du contrôle du degré d'hydratation du corps humain basé sur la mesure du temps nécessaire au sang pour remplir à nouveau un vaisseau sanguin occlus, notamment en mesurant le temps de remplissage veineux (TRV) et/ou le temps de remplissage capillaire (TRC). L'invention propose un procédé I dans lequel le tissu comprenant le vaisseau sanguin est exposé à un rayonnement lumineux à polarisation linéaire à au moins une longueur d'onde prédéfinie ; la partie de la lumière réfléchie qui est polarisée perpendiculairement au rayonnement lumineux appliqué est recueillie sous la forme d'une image ; le vaisseau sanguin est occlus afin d'empêcher le sang d'y circuler ; l'occlusion du vaisseau sanguin est supprimée afin de permettre au sang de remplir à nouveau le vaisseau sanguin ; l'image est analysée afin de déterminer l'écoulement des cellules sanguines ; et le temps nécessaire pour revenir à un débit prédéfini des cellules sanguines après la suppression de l'occlusion est mesuré. Ce procédé permet de contrôler aisément, de manière spécifique et précise, le degré d'hydratation du corps humain.
PCT/IB2008/054371 2007-10-25 2008-10-23 Contrôle du degré d'hydratation du corps humain WO2009053920A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN200710167897.7 2007-10-25
CN200710167897 2007-10-25

Publications (1)

Publication Number Publication Date
WO2009053920A1 true WO2009053920A1 (fr) 2009-04-30

Family

ID=40332870

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/IB2008/054371 WO2009053920A1 (fr) 2007-10-25 2008-10-23 Contrôle du degré d'hydratation du corps humain

Country Status (1)

Country Link
WO (1) WO2009053920A1 (fr)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2011078882A1 (fr) * 2009-12-24 2011-06-30 Children's Medical Center Corporation Appareil et procédé de diagnostic à base de temps de remplissage capillaire
CN104346604A (zh) * 2013-07-26 2015-02-11 株式会社日立制作所 血管图像获取装置以及终端
WO2015155526A1 (fr) * 2014-04-08 2015-10-15 The University Of Nottingham Mesure de remplissage de capillaire
EP3000388A1 (fr) * 2014-09-29 2016-03-30 Nihon Kohden Corporation Capteur et système de mesure de signal biologique
WO2016087556A1 (fr) 2014-12-02 2016-06-09 Jacquet-Lagreze Matthias Dispositif, système et procédé d'évaluation de la microcirculation sanguine d'un tissu
US20170209091A1 (en) * 2016-01-22 2017-07-27 Welch Allyn, Inc. Estimating Hydration Using Capillary Refill Time
JP2018108278A (ja) * 2017-01-04 2018-07-12 京セラ株式会社 推定装置、推定システム、推定方法及び推定プログラム
US10231667B2 (en) 2014-10-31 2019-03-19 Koninklijke Philips N.V. Non-invasive dehydration monitoring
RU2712047C2 (ru) * 2014-12-15 2020-01-24 Конинклейке Филипс Н.В. Способ измерения времени наполнения капилляров

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0714628A1 (fr) * 1994-11-30 1996-06-05 TOA MEDICAL ELECTRONICS CO., Ltd. Analyseur destiné à l'examen non-invasif du sang
US5983120A (en) * 1995-10-23 1999-11-09 Cytometrics, Inc. Method and apparatus for reflected imaging analysis
US20040249290A1 (en) * 1999-07-26 2004-12-09 Cardiosense Non-invasive method and apparatus to detect and monitor early medical shock, and related conditions
WO2005063116A1 (fr) * 2003-12-22 2005-07-14 Koninklijke Philips Electronics N. V. Appareil et procede permettant de realiser l'imagerie spectrale polarisee orthogonale (opsi)
US20050187478A1 (en) * 2001-07-16 2005-08-25 Art, Advanced Research Technologies Inc. Multi-wavelength imaging of highly turbid media
WO2007086071A2 (fr) * 2006-01-30 2007-08-02 Cardiosense Ltd. Appareil, systeme et procede de determination d’etat cardio-respiratoire

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0714628A1 (fr) * 1994-11-30 1996-06-05 TOA MEDICAL ELECTRONICS CO., Ltd. Analyseur destiné à l'examen non-invasif du sang
US5983120A (en) * 1995-10-23 1999-11-09 Cytometrics, Inc. Method and apparatus for reflected imaging analysis
US20040249290A1 (en) * 1999-07-26 2004-12-09 Cardiosense Non-invasive method and apparatus to detect and monitor early medical shock, and related conditions
US20050187478A1 (en) * 2001-07-16 2005-08-25 Art, Advanced Research Technologies Inc. Multi-wavelength imaging of highly turbid media
WO2005063116A1 (fr) * 2003-12-22 2005-07-14 Koninklijke Philips Electronics N. V. Appareil et procede permettant de realiser l'imagerie spectrale polarisee orthogonale (opsi)
WO2007086071A2 (fr) * 2006-01-30 2007-08-02 Cardiosense Ltd. Appareil, systeme et procede de determination d’etat cardio-respiratoire

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
SHAVIT ITAI ET AL.: "A Novel Imaging Technique to Measure Capillary-Refill Time: Improving Diagnostic Accuracy for Dehydration in Young Children with Gastroenteritis", PEDIATRICS, no. 118, 2006, pages 2402 - 2408, XP002514733 *

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20130211216A9 (en) * 2009-12-24 2013-08-15 Childeren's Medical Center Corporation Capillary refill time diagnostic apparatus and methods
WO2011078882A1 (fr) * 2009-12-24 2011-06-30 Children's Medical Center Corporation Appareil et procédé de diagnostic à base de temps de remplissage capillaire
US9603559B2 (en) 2009-12-24 2017-03-28 Children's Medical Center Corporation Capillary refill time diagnostic apparatus and methods
CN104346604A (zh) * 2013-07-26 2015-02-11 株式会社日立制作所 血管图像获取装置以及终端
EP2848196A1 (fr) * 2013-07-26 2015-03-18 Hitachi Ltd. Appareil pour la photographie des vaisseau sanguins
WO2015155526A1 (fr) * 2014-04-08 2015-10-15 The University Of Nottingham Mesure de remplissage de capillaire
EP3000388A1 (fr) * 2014-09-29 2016-03-30 Nihon Kohden Corporation Capteur et système de mesure de signal biologique
US10231667B2 (en) 2014-10-31 2019-03-19 Koninklijke Philips N.V. Non-invasive dehydration monitoring
WO2016087556A1 (fr) 2014-12-02 2016-06-09 Jacquet-Lagreze Matthias Dispositif, système et procédé d'évaluation de la microcirculation sanguine d'un tissu
RU2712047C2 (ru) * 2014-12-15 2020-01-24 Конинклейке Филипс Н.В. Способ измерения времени наполнения капилляров
US11622690B2 (en) 2014-12-15 2023-04-11 Koninklijke Philips N.V. Approach for measuring capillary refill time
US20170209091A1 (en) * 2016-01-22 2017-07-27 Welch Allyn, Inc. Estimating Hydration Using Capillary Refill Time
US11344254B2 (en) * 2016-01-22 2022-05-31 Welch Allyn, Inc. Estimating hydration using capillary refill time
JP2018108278A (ja) * 2017-01-04 2018-07-12 京セラ株式会社 推定装置、推定システム、推定方法及び推定プログラム

Similar Documents

Publication Publication Date Title
WO2009053920A1 (fr) Contrôle du degré d'hydratation du corps humain
CN107106051B (zh) 无创脱水监测
US8788003B2 (en) Monitoring blood constituent levels in biological tissue
US20120277559A1 (en) Apparatus for Measuring Blood Parameters
EP1292216B1 (fr) Dispositif de mesure de concentration de glucose ou d'autres substances dans le sang
JP5394501B2 (ja) 血管状態モニタリング方法
CN106659392A (zh) 非侵扰式皮肤组织水合确定设备及相关的方法
EP2734113B1 (fr) Dispositif non invasif et procédé de mesure de taux de bilirubine
US20210298652A1 (en) Hemoglobin measurement from a single vessel
CN115399759A (zh) 无创性血液分析
WO2017189376A1 (fr) Suivi du traitement de la maladie artérielle périphérique (pad) au moyen de l'imagerie optique diffuse
JP6444857B2 (ja) ファイバー無し透過反射型プローブを使用した分析物濃度の非侵襲測定
JPH07136151A (ja) 血液成分の濃度を検出する方法及び装置並びにこの装置を較正するための装置
Kumar et al. NIR-based Sensing System for Non-invasive Detection of Hemoglobin for Point-of-care Applications
JP2011179994A (ja) 濃度に依存しない吸光度スペクトル測定法
JP2019025292A (ja) 肌状態の評価方法
Golberg et al. Analysis of peripheral arterial disease (PAD) patients by laser speckle measurement techniques
Chiba et al. Advanced multispectral image-processing endoscopy system for visualizing two-dimensional hemoglobin saturation and relative hemoglobin concentration
Cysewska-Sobusiak Examples of acquisition and application of biooptical signals
Dinçer Kılıç THE REFLECTANCE OF HUMAN SKIN IN THE EXTENDED INFRARED REGION USING A FABRY-PEROT BASED SPECTRAL MEASUREMENT TECHNIQUE
US20130267798A1 (en) Noninvasive measurement of analyte concentration using a fiberless transflectance probe
Yable et al. Optical Characterization of Buruli Ulcer by Diffuse Reflectance using LEDs illumination
Humphreys et al. A CMOS camera-based system for non-contact pulse oximetry imaging
WO2014052040A2 (fr) Oxymétrie absolue non invasive du tissu cérébral

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 08843114

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 08843114

Country of ref document: EP

Kind code of ref document: A1