Patent ID: 12203844

DETAILED DESCRIPTION

Embodiments of the inventive concept will now be described in detail with reference to the accompanying drawings. The advantages and features of embodiments of the inventive concept, and methods for achieving the advantages and features will be apparent from the embodiments described in detail below with reference to the accompanying drawings. However, the inventive concept may be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the inventive concept to those skilled in the art, and the inventive concept is only defined by the scope of the claims. Like reference numerals refer to like elements throughout.

The terminology used herein is not for delimiting the embodiments of the inventive concept but for describing the embodiments of the inventive concept. The terms of a singular form may include plural forms unless otherwise specified. It will be further understood that the terms “includes”, “including”, “comprises”, and/or “comprising”, when used in this description, specify the presence of stated elements, steps, operations, and/or components, but do not preclude the presence or addition of one or more other elements, steps, operations, and/or components. Reference numerals, which are presented in the order of description, are provided according to the embodiments and are thus not necessarily limited to the order.

FIG.1illustrates an example of a photo-acoustic sensor device100according to the inventive concept.

Referring toFIG.1, the photo-acoustic sensor device100of an embodiment of the inventive concept may be a photo-acoustic-based sensor device. According to an example, the photo-acoustic sensor device100may include light sources10, detectors20, and a control unit40. The light sources10may generate an ultrasonic wave16by providing a source light12to a subject44. The light sources10each may include a laser, a laser diode, or a light-emitting diode. The source light12may include a first source light11and a second source light13according to a wavelength thereof. Similarly, the ultrasonic wave16may include a first ultrasonic wave15and a second ultrasonic wave17according to a wavelength thereof. The subject44may include human skin tissue. A support body42may be in contact with the subject44and transfer the ultrasonic wave16to the detectors20. The support body42may include a solid polymer. The detectors20may receive the ultrasonic wave16to generate a detection signal. The detectors20each may include a piezoelectric sensor, but an embodiment of the inventive concept is not limited thereto. The control unit40may calculate a value of glucose concentration in the subject44by comparing the detection signal with a reference signal, but an embodiment of the inventive concept is not limited to measuring the concentration of glucose. Furthermore, the control unit40may determine whether the subject44has a disease, but an embodiment of the inventive concept is not limited thereto. The control unit40may detect a temperature of the support body42and the subject44.

FIG.2shows sensitivity according to an absorption coefficient of the subject44.

Referring toFIG.2, the subject44may generate the ultrasonic wave16with an absorption coefficient that changes according to the wavelength of the source light12. A magnitude and characteristic of the generated ultrasonic wave16are determined by the absorption coefficient or the wavelength of the source light12. For example, the wavelength of the source light12having an absorption coefficient of greater than 2000/m has sensitivity of a desensitization range46in which an ultrasonic characteristic change is small, and may be used as the first source light11for generating the reference signal. The wavelength of the source light12having an absorption coefficient of less than 2000/m has sensitivity of a sensitization range48in which an ultrasonic characteristic change is significant, and may be used as the second source light13for generating the detection signal.

FIG.3shows an absorption coefficient of water according to the wavelength of the source light12ofFIG.1.

Referring toFIGS.1to3, the source light12, which generates the reference signal and the detection signal, may include near-infrared light having a wavelength of about 900 nm to about 3000 nm.

According to an embodiment, the first source light11having an absorption coefficient of the desensitization range46may have a first wavelength λ1. For example, the first wavelength Ai may be about 1400 nm to about 1500 nm. The first wavelength λ1may have a peak of about 1450 nm. Alternatively, the first wavelength λ1may be about 1800 nm to about 2500 nm. The first wavelength λ1may have a peak of about 1950 nm.

According to an embodiment, the second source light13having an absorption coefficient of the sensitization range48may have a second wavelength λ2. For example, the second wavelength λ2may be about 1500 nm to about 1800 nm. Alternatively, the second wavelength λ2may be about 1400 nm or less.

The first source light11and the second source light13may respectively generate the first ultrasonic wave15and the second ultrasonic wave17in the subject44. A magnitude and characteristic of the generated first ultrasonic wave15and second ultrasonic wave17may be affected not only by the absorption coefficient of the subject44but also by a size of the subject44, a characteristic of the support body42, and a characteristic of the detector20. Since the magnitude and characteristic of the first ultrasonic wave15are unsusceptible to a change in the absorption coefficient of the subject44, a measurement signal of the first ultrasonic wave15may be used as a reference signal for correcting a signal change due to a change in the size of the subject44, the characteristic of the support body42, and the characteristic of the detector20. That is, the reference signal of the first ultrasonic wave15may be obtained as noise or a noise value.

On the contrary, since the magnitude and characteristic of the second ultrasonic wave17generated by the second source light13having a wavelength corresponding to the sensitization range48are susceptible to a change in the absorption coefficient, a measurement signal of the second ultrasonic wave17may be used as a detection signal for measuring an absorption coefficient value of the subject44. The detection signal of the second ultrasonic wave17may be obtained as a measurement value.

A change in the characteristic of the second ultrasonic wave17due to the subject44, the support body42, and the detector20may be similar to the change in the characteristic of the first ultrasonic wave15. The control unit40may precisely extract the absorption coefficient of the subject44without being influenced by external noise by using the first ultrasonic wave15as the reference signal and the second ultrasonic wave17as the detection signal. The control unit40may obtain an absorption coefficient value using a signal magnitude change, phase difference change, or the like of the reference signal and the detection signal. That is, the control unit40may obtain the absorption coefficient value by removing a noise value of the reference signal from the measurement value of the detection signal. Furthermore, the control unit40may obtain a blood glucose value by comparing the absorption coefficient value with the reference value. The control unit40may include a program for calculating a changed absorption coefficient as a blood glucose value, but an embodiment of the inventive concept is not limited thereto.

FIG.4illustrates an example of a photo-acoustic sensor device100according to the inventive concept.

Referring toFIG.4, the photo-acoustic sensor device100may further include an optical switch50and an optical coupler. The optical switch50may be provided between the light sources10and the subject44. The optical switch50may switch the first source light11and the second source light13. The detector20may be provided on one side of the subject44and the support body42opposing the optical switch50. The light sources10, the subject44, the support body42, and the control unit40may be configured in the same manner as illustrated inFIG.1.

FIG.5illustrates an example of a photo-acoustic sensor device100according to the inventive concept.

Referring toFIG.5, the optical switch50of the photo-acoustic sensor device100may be provided at a front end of the light sources10. The optical switch50may switch the first source light11and the second source light13provided to the light sources10. In the case where the light sources10include an optical fiber laser, the optical switch50may switch pump lights. The light sources10, the subject44, the support body42, the detector20, and the control unit40may be configured in the same manner as illustrated inFIGS.1and4.

A photo-acoustic sensing method of the photo-acoustic sensor device100of the inventive concept configured as above is described below.

FIG.6illustrates a photo-acoustic sensing method of a photo-acoustic sensor device100according to the inventive concept.

Referring toFIGS.1and6, the light sources10provide the first source light11and the second source light13to the subject44(S10). The first source light11and the second source light13may be absorbed in the subject44so as to respectively generate the first ultrasonic wave15and the second ultrasonic wave17. The first source light11may have an absorption coefficient or wavelength corresponding to the desensitization range46, and the second source light13may have an absorption coefficient or wavelength corresponding to the sensitization range48. The first source light11and the second source light13may include near-infrared light having a wavelength of about 900 nm to about 3000 nm. The first source light11may have a first wavelength λ1of about 1400 nm to about 1500 nm or about 1800 nm to about 2500 nm. The second source light13may have a second wavelength λ2of about 1500 nm to about 1800 nm or about 1400 nm or less. The first ultrasonic wave15and the second ultrasonic wave17may be transferred to the detector20through the support body42.

Next, the detector20receives the first ultrasonic wave15and the second ultrasonic wave17(S20). The detector20may generate a reference signal and a detection signal by receiving the first ultrasonic wave15and the second ultrasonic wave17. The reference signal and the detection signal may be obtained as a measurement value and a noise value.

Next, the control unit40obtains an absorption coefficient value by removing the noise value extracted by the first ultrasonic wave15from the measurement value extracted by the second ultrasonic wave17(S30).

Furthermore, the control unit40obtains a blood glucose value by comparing the absorption coefficient value with a reference value (S40). The absorption coefficient value may be quantitatively determined according to the reference value.

Although not illustrated, the control unit40may use the absorption coefficient value and the reference value to determine whether the subject44has diabetes, but an embodiment of the inventive concept is not limited thereto.

As described above, a photo-acoustic sensor device and a photo-acoustic sensing method of the same according to an embodiment of the inventive concept may remove or minimize photo-acoustic noise using an ultrasonic wave generated by a source light having a first wavelength of about 1400 nm to about 1500 nm or about 1800 nm to about 2500 nm in a near-infrared band, which is unsusceptible to an external environment.

Although the embodiments of the present invention have been described, it is understood that the present invention should not be limited to these embodiments but various changes and modifications can be made by one ordinary skilled in the art within the spirit and scope of the present invention as hereinafter claimed.