Non-Invasive System and Method for Measuring Skin Hydration of a Subject

• US 20080275319A1
• Filed: 12/26/2006
• Published: 11/06/2008
• Est. Priority Date: 12/28/2005
• Status: Active Grant

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Van Herpen, Maarten Marinus Johannes Wilhelmus, Van Gogh, Antonius Theodorus Martinus
• Granted Patent: US 8,043,227 B2
• Time in Patent Office: Days
• US Class Current: 600/316
• CPC Class Codes: A61B 5/0095 by applying light and detecting acoustic waves, i.e. photoacoustic measurements
• CPC Class Codes: A61B 5/01 Measuring temperature of body parts ; Diagnostic temperature sensing, e.g. for malignant or inflamed tissue clinical contact thermometers G01K13/20
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/14546 for measuring analytes not otherwise provided for, e.g. ions, cytochromes
• CPC Class Codes: A61B 5/441 Skin evaluation, e.g. for skin disorder diagnosis
• CPC Class Codes: A61B 5/4869 Determining body composition

Abstract

A non-invasive system and method for measuring skin hydration of a subject comprising a thermistor (7) used in transient mode to obtain a measurement of the thermal conductivity of the skin of the subject and a processor (8) for determining a skin hydration value from the thermal conductivity measurement. The system for measuring skin hydration may be comprised in a non-invasive system for detecting blood analyte concentration, preferably glucose, including a spectroscopic device having e.g. an infrared source (2) which generates infrared beam (3) and detector (6) for detecting transmitted radiation through portion 1 (e.g. finger) of a subject. The system may also include skin hydrator (9) which moisturises the skin connected in a control loop to the system for measuring skin hydration. The system for detecting blood analyte concentration may include a photoacoustic device or a metabolic heat conformation device.

Claims

1. A non-invasive system for measuring skin hydration of a subject comprising;

a thermal conductivity measuring apparatus for obtaining a measurement of the thermal conductivity of the skin of the subject and

a processor for determining a skin hydration value from the thermal conductivity measurement.

2. A non-invasive system according to claim 1, wherein the thermal conductivity measuring apparatus comprises;

a thermistor in thermal connection with the skin of the subject in use and

a current supply for supplying current to the thermistor sufficient to maintain the resistance or temperature of the thermistor at a predetermined level,

wherein the thermal conductivity measuring apparatus obtains a measurement of the thermal conductivity in dependence upon the current supplied to the thermistor.

3. A non-invasive system according to claim 1 comprised in a non-invasive system for detecting blood analyte concentration.

4. A non-invasive system according to claim 3, wherein the system for detecting analyte blood concentration comprises one or more of:

a spectroscopic device;

a photoacoustic device,

a device for determining blood glucose concentration based on the metabolic heat conformation method.

5. A non-invasive system according to claim 1, comprising a skin hydrating means.

6. An non-invasive system according to claim 5, wherein the non-invasive system for measuring skin hydration is connected in a control loop to the skin hydrating means so the skin hydration is maintainable at a predetermined level.

7. A non-invasive system according to claim 3, wherein the analyte concentration measured is glucose concentration.

8. A method for measuring skin hydration comprising the steps of:

non-invasively measuring the thermal conductivity of the skin;

determining the hydration level of the skin from the thermal conductivity.