Noninvasive measuring device for substance in blood via nail and a nail evaporation device

• US 8,145,286 B2
• Filed: 11/30/2006
• Issued: 03/27/2012
• Est. Priority Date: 11/30/2005
• Status: Expired due to Fees

• Current Assignee: KEIO University, Tanita Corporation (Tanita)
• Original Assignee: KEIO University, Tanita Corporation (Tanita)
• Inventors: Arai, Tsunenori, Kawase, Yuki, Oka, Yasunobu, Ito, Narushi
• Primary Examiner(s): Winakur, Eric
• Assistant Examiner(s): Liu, Chu Chuan (JJ)
• Application Number:
  US11/606,155
• Publication Number:
  US 20070161877A1
• Time in Patent Office: 1,944 Days
• Field of Search: 600/310, 600/315, 600/316, 600/322, 600/331, 600/340, 600/365, 604/20, 606/9
• US Class Current: 600/322
• CPC Class Codes: A61B 18/203 applying laser energy to the outside of the body
• CPC Class Codes: A61B 2017/00061 spectrum
• CPC Class Codes: A61B 2017/00765 Decreasing the barrier function of skin tissue by radiated energy, e.g. using ultrasound, using laser for skin perforation
• CPC Class Codes: A61B 2018/00452 Skin
• CPC Class Codes: A61B 2018/00625 Vaporization
• CPC Class Codes: A61B 2018/00779 Power or energy
• CPC Class Codes: A61B 2018/00785 Reflected power
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/1455 using optical sensors, e.g. spectral photometrical oximeters
• CPC Class Codes: A61N 5/062 Photodynamic therapy, i.e. excitation of an agent

Abstract

A device and method for optically measuring a substance in blood using the nail as an optical window are provided. A device for optically measuring a test substance in blood by using the nail as an optical window and correcting or eliminating fluctuation of a measurement value based on optical characteristics of the nail plate, comprising irradiation means applying light within a wavelength range for measuring absorption by the test substance to the nail of a subject, detection means detecting light diffused/reflected from or transmitted through the body of the subject, and processing means processing a signal obtained by the detection means to convert the signal into a concentration of the test substance.

Claims

1. A device for optically measuring a test substance in blood by using a nail as an optical window which comprises:

(i) a nail plate evaporation device, which partly removes a nail plate by evaporating the nail plate for creating an optical window in the nail, which comprises (a) a light generator generating a coherent light, (b) an evaporation depth monitor having a light detector detecting fluorescence emitted from the nail plate and the dermis for monitoring evaporation depth of the nail plate, and a controller which processes the detected fluorescence to determine evaporation depth information of the nail plate for controlling the light generator;

(ii) an irradiator configured to apply light within a wavelength range for measuring absorption by the test substance through the optical window;

(iii) a detector configured to detect light diffused/reflected from or transmitted through the body of a subject;

(iv) a processor configured to process a signal obtained by the detector to convert the signal into a concentration of the test substance;

(v) a monitor configured to monitor a water content and a keratin content of the nail by using light within a wavelength range for measuring absorption by water in the nail and light within a wavelength range for measuring absorption by keratin in the nail to correct or eliminate optical characteristics of the nail plate in the detected light.

2. The device according to claim 1, wherein the irradiator and the detector are contained in a probe, and light is applied by the irradiator through the nail into the body of the subject and light diffused/reflected from the body of the subject is detected by the detector through the nail.

3. The device according to claim 1, wherein the irradiator applying light within a wavelength range for measuring absorption by the test substance to the nail applies light to capillary vessel of the nail bed portion.

4. The device according to claim 1, wherein the irradiator applying light within a wavelength range for measuring absorption by the test substance to the nail applies near infrared light.

5. The device according to claim 4, wherein the wavelength range of the light to be applied is 1 to 2.5 μ

m.

6. The device according to claim 1, wherein the device is a blood glucose level measuring device.

7. The device according to claim 1, wherein the device is used for measuring blood urea, creatinine, BUN, or CP (creatinine phosphokinase).

8. The device according to claim 1, wherein the monitor uses light having a wavelength of 1 to 3 μ

m as the light within a wavelength range for measuring absorption by water in the nail and light having a wavelength of 1 to 2.5 μ

m as the light within a wavelength range for measuring absorption by keratin in the nail.

9. The device according to claim 1, wherein the coherent light source is ultraviolet laser light or OPO.

10. The device according to claim 9, wherein the ultraviolet laser light is ArF laser light.

11. The device according to claim 1, wherein a pulse energy density of the coherent light from the light generator is not less than 10 mJ/cm²·

pulse.

12. The device according to claim 1, wherein, in monitoring the evaporation depth of the nail plate, irradiation is performed with a fluence such that intensity of plume emission, which is simultaneously generated in a wavelength range of fluorescence generating during light irradiation for evaporation, is equal to or less than intensity of fluorescence emitted from the nail plate and/or the dermis.

13. The device according to claim 1, further comprising a holder of a finger tip portion, which has the laser light irradiator and the light detector.