WO2009096630A1

WO2009096630A1 - A surface acoustic wave sensor for detecting a lung cancer

Info

Publication number: WO2009096630A1
Application number: PCT/KR2008/001817
Authority: WO
Inventors: Gi Beum Kim; Hyung Sub Kang; Chul Un Hong; Woo Suk Chong; Seol Hee Jeon; Jin Shang Kim; Min Ho Kim; Sung Jong Kim; In Shick Kim; Sung Zoo Kim
Original assignee: Industrial Cooperation Foundation Chonbuk National University
Priority date: 2008-01-31
Filing date: 2008-04-01
Publication date: 2009-08-06
Also published as: KR100894800B1

Abstract

A surface acoustic wave (SAW) sensor for detecting lung cancer is provided, the SAW sensor includes a base cap, a sensor cap removably connected to the base cap, the sensor cap on which an air hole is formed,a SAW signal generating unit formed inside the sensor cap, and a SAW signal transferring unit connected to the SAW signal generating unit to transfer generated SAW signal, wherein the SAW generating unit comprises at least six sensing films of different frequencies, in which each of the six sensing films comprises a substrate on which an electrode and a polyimide are coated.

Description

A SURFACE ACOUSTIC WAVE SENSOR FOR DETECTING A

LUNG CANCER

Technical Field

[1] The present invention relates to a surface acoustic wave (SAW) sensor for detecting lung cancer, and more particularly, to a SAW sensor for detecting lung cancer using patient's breath gas. Background Art

[2] Generally, a surface acoustic wave (SAW) sensor is applied to measure a variety of parameters such as temperature, pressure, or the like. For example, the SAW sensor may be used to monitor tire's pressure or temperature, or to measure contamination of soil or water by measuring an amount of volatile organic compounds (VOCs) contained therein. Related technologies regarding a SAW sensor can be referred to U.S Patent Publications Nos. 2005015648, 20060075820, and 20070164633.

[3] Unlike the breath of a healthy person, the breath of a patient having lunc cancer contains VOCs such as isoprene, benzene, or alkane, and based on this, researches have been conducted to utilize the SAW sensor as a lung cancer diagnostic sensor, since the

LiNbO ₃

(LN) or quartz SAW sensor can measure VOCs. These efforts were accelerated due to convenience they provide, since it is enabled to detect lung cancer by simply measuring the amount of VOCs contained in the patient's breath, instead of undergoing conventional diagnostic measures such as endoscope, blood test, or hitological examination which is quite time and effort consuming.

[4] However, the conventional LN or quartz SAW sensor for lung cancer diagnosis suffers drawbacks of degraded accuracy, since the patient's breath directly collides against the surface of the sensing film, causing the sensing film to be affected by pressure. The conventional LN or quartz SAW sensor for lung cancer diagnosis also has degraded measurement reliability, since a great deal of patient's breath is not captured by the sensor film but disregarded, and a small amount of VOCs is neglected and thus lung cancer is not detected if the patient is in an early stage. Disclosure of Invention Technical Problem

[5] Accordingly, it is an object of the present invention to provide a surface acoustic wave (SAW) sensor for detecting lung cancer, which provides high detection accuracy and reliability in measuring an amount of volatile organic compounds (VOC) contained in a patent's breath. Technical Solution

[6] A surface acoustic wave (SAW) sensor for detecting lung cancer according to the present invention may include a base cap, a sensor cap removably connected to the base cap, the sensor cap on which an air hole is formed, a SAW signal generating unit formed inside the sensor cap, and a SAW signal transferring unit connected to the SAW signal generating unit to transfer generated SAW signal, wherein the SAW generating unit comprises at least six sensing films of different frequencies, in which each of the six sensing films comprises a substrate on which an electrode and a polyimide are coated.

[7] The sensing films may be formed in a manner in which a direction in which upper surfaces are faced is perpendicular to a direction in which a patient's breath flows in, so that the patient's breath does not directly collide against wider surfaces of the sensing films.

[8] According to an embodiment of the present invention, the SAW signal generating unit may include a jig member having a jig base in which output channels are formed radially, and the sensing films may be arranged radially on the output channels at pre- determiend intervals.

[9] According to another embodiment of the present invention, the sening films may be parallel to each other at predetermined intervals.

[10] The sensing films may each include a substrate, an input electrode and an output electrode coated on the substrate, and a polyimide formed between the input and output electrodes.

[11] The SAW signal genenerating unit may include six sensing films, in which each of the six sensing films has a frequency of 100 MHz, 200 MHz, 300 MHz, 400 MHz, 500 MHz, and 600 MHz.

Advantageous Effects

[12] According to aspects of the present invention, a surface acoustic wave (SAW) sensor includes a polyimide disposed between an input electrode and an output electrode, and six or more sensing films of different frequencies, and accordingly, it is possible to detect even an minute amount of volatile organic compounds (VOC) contained in the patient's breath and provide VOC gas measurments with improvded accuracy and reliability.

[13] Furthermore, the SAW sensor is formed in a manner in which the patient's breath does not directly collide against the wider surface of the sensing films, thereby decreasing impacts from the flow pressure of the patient's breath. The SAW sensor is also formed in a manner in which the sensing films are at predetermined distance from each other in parallel or radial alignment, thereby decreasing the amount of VOC being disregarded and also decreasing interfrence between SAW signals generated from the respective SAW sensing films.

[ 14] [Brief description of the drawings]

[15] FIG. 1 is a perspective view of a surface acoustic wave (SAW) sensor for detecting lung cancer according to a first embodiment of the present inveniton;

[16] FIG. 2 is a plan view provided to explain the structure of a sensing filme of the SAW sensor of FIG. 1;

[17] FIG. 3 is a view provided to explain the structure of a sensing film of the SAW sensor according to a second embodiment of the present invention; and

[18] FIG. 4 is a block diagram provided to explain a process of detecting lung cancer using a signal transfered from the SAW sensor according to the first or second embodiment of the present invention. Best Mode for Carrying out the Invention

[19] The present invention will be explained below with reference to the accompanying drwaings.

[20] FIGS. 1 and 2 illustrate a surface acoustic wave (SAW) sensor according to a first embodiment of the present invention, in which the SAW sensor includes a base cap 16, a sensor cap 12, a SAW signal generating unit 30, and a SAW ignal transferring unit 84.

[21] A cable 80, which is connected to a SAW signal reader 100 at the back, is attached to the base cap 16 (see FIG. 4). The front portion of the base cap 16 is formed in a manner to enable the sensor cap 12 to be attached removably. The base cap 16 has a hollow cylindrical shape, so that a connection jack of the cable 80 is inserted in the cylindrical base cap 16 and connected to a connection jack 82 of the SAW signal transferring unit 84.

[22] Similar to the base cap 16, the sensor cap 12 has a hollow cylindrical shape. The sensor cap 12 is removably connected to the front portion of the base cap 16. A first side 13 of the base cap 16 is closed, excluding air holes 14 to pass the patient's breath, and a second side is open. The air holes 14 may include a plurality of small openings, and the areas of the air holes 14 are recessed from the first side 13 of the base cap 16.

[23] The SAW signal generating unit 30 is formed on an upper surface of a bracket 81 which is provided inside the sensor cap 12, and includes a supporting plate 45, a jig member 34, and a first to sixth sensing films 1, 2, 3, 4, 5, 6.

[24] The supporting plate 45 is formed in a rectangular shape, and fixed to an upper surface of the bracket 81 to support the jig member 34, and as shown in FIG. 1 , formed in a lengthwise direction of the sensor cap 12, that is, in the same direction as that of the bracket 81.

[25] The jig member 34 includes a jig wall 21, a jig base 32, and a cover 27. The jig base

32 is formed in a rectangular shape and in a similar size to that of the supporting plate 45. The jig wall 21 is formed to wrap around the edge of the base 32 to a predetermined height. Openings 23, 21 are formed in one side of the jig wall 21 in a direction in which the patient's breath A flows in or out, so that the patient's breath can reach the sensing films 1, 2, 3, 4, 5, 6, respectively.

[26] Referring to FIGS. 1 and 2, the first to sixth sensing films 1, 2, 3, 4, 5, 6 include first to sixth substrates 50, 52, 54, 56, 58, 60, first to sixth input electrodes 36, 38, 40, 42, 44, 46, first to sixth output electrodes 33, 35, 37, 39, 41, 43, and polyimides 31. The first to sixth sensing films 1, 2, 3, 4, 5, 6 are formed on the jig base 32, at predetermined intervals and along the same direction. The sensing films 1, 2, 3, 4, 5, 6 are formed in a manner in which a direction where the wider faces thereof, on which the electrodes and polyimide are formed on (FIGS. 2 and 3), are faced, are perpendicular to a direction in which the patient's breath flows in, so that the patient's breath is prevented from colliding against the wider faces of the sensing films 1, 2, 3, 4, 5, 6 directly. In other words, the lengthwise direction of the first to sixth sensing films 1, 2, 3, 4, 5, 6 is perpendicular, or almost perpendicular to a direction A (FIG. 2) in which the patient's breath flows in, and the first to sixth sensing films 1, 2, 3, 4, 5, 6 are arranged parallel in the identical shapes. While the first to sixth sensing films 1, 2, 3, 4, 5, 6 have the identical structures, since different level of voltages are input, each of the electrodes has different shape of electric wire or protruding wires at different intervals (see FIG. 2). Accordingly, different SAW frequencies are generated. For example, the first sensing film 1 may generate 100 MHz, the second sensing film 2 may generate 200 MHz, the third sensing film 3 may generate 300 MHz, the fourth sensing film 4 may generate 400 MHz, the fifth sensing film 5 may generate 500 MHz, and the sixth sensing film 6 may generate 600 MHz.

[27] Since the first to sixth substrates 50, 52, 54, 56, 58, 60 are at predetermined intrvals, interference between SAW signals generated from the neighboring sensing films may be reduced. For example, the first and second substrates 50, 52 may be arranged parallel on the supporting plate 45 at predetermined intervals, while the second to sixth substrates 52, 54, 56, 58 are arranged in the same direction and at a predetermined distance from each other. Each of the first to sixth subtrates 50, 52, 54, 56, 58, 60 is made from the same materials, that is,

LiNbO ₃ and quartz. [28] The first to sixth input electrodes 36, 38, 40, 42, 44, 46, and the first to sixth output electrodes 33, 35, 37, 39, 41, 43 are coated on the first to sixth substrates 50, 52, 54, 56, 58, 60. That is, the first input electrode 36 and the first output electrode 33 are coated on the first substrate 50, and the rest electrodes are coated on the corresponding substrates in the same manner, respectively. Each of the input and output electrodes is formed of a positive (+) electric line and a ground line. For example, the first input electrode 36 may include a positive line 36a and a ground line 36b, and the first output electrode 33 may include a positive line 33b and a ground line 33b.

[29] The polyimides (collectively referred to by reference numeral '31 ') of the same shape and structure are formed in the same positions between the input and output electrodes. The polyimide 31 adsorbs VOC, and the characteristic of the SAW signal transferred from the input electrodes to the output electrodes is varied depending on the amount of VOC adsorbed in the polyimides 31.

[30] Referring to FIG. 1, the SAW signal transferring unit 84 includes a transfer board 86, a connection jack 82, and an interface chip 88. The transfer board 86 is formed on the bracket 81, and the interface chip 88 and the connection jack 82 are fixed on the transfer board 86 and electrically connected to each other. The interface chip 88 is electrically connected to the first to sixth sensing films 1, 2, 3, 4, 5, 6 of the SAW signal generating unit 30. That is, the interface chip 88 receives SAW signals output from the first to sixth output electrodes 33, 35, 37, 39, 41, 43 and transfers the received signals to the SAW signal reader 100 via the connection jack 82 and the cable 80 (see FIG. 4).

[31] FIG. 3 illustrates the SAW sensor for detecting lung cancer according to the second embodiment, and in particular, illustrates a portion of the SAW signal generating unit. The rest components of the SAW sensor according to the second embodiment are same as those of the first embodiment.

[32] FIG. 3 is a plan view of the jig base 32' and the first to sixth sensing films 1, 2, 3, 4,

5, 6. As explained above, not only the components of the SAW signal generating unit such as the jig member 34 or the supporting plate 45, but also the components of the SAW sensor of the second embodiment are identical to those of the first embodiment (see FIG. 1) except the components indicated otherwise, and accordingly, the like elements of the first and second embodiments will be given the same reference numerals throughout the description.

[33] The jig base 32 includes an input channel 63, a first to sixth output channels 62, 64,

66, 68, 70, 72, and a partition 61 to define the channels. Referring to FIG. 3, the input channel 63 is formed in a direction A where the patient's breath blows in, and the first to sixth output channels 62, 64, 66, 68, 70, 72 are formed radially. Since the first to sixth output channels 62, 64, 66, 68, 70, 72 are isolated from each other by the partition 61, the patient's breath is not mixed therein. The first to sixth sensing films 1, 2, 3, 4, 5, 6 are identical to those of the first embodiment, but unlike the first embodiment, the first to sixth sensing films 1, 2, 3, 4, 5, 6 according to the second embodiment are arranged in a radial pattern on the output channels 62, 64, 66, 68, 70, 72. The first to sixth sensing films 1, 2, 3, 4, 5, 6 are formed perpendicular to a direction in which the patient's breath flows along the output channels 62, 64, 66, 68, 70, 72, and like the first embodiment, a direction where the wider surfaces of the sensing films (on which the polyimides 31 are formed) are faced, are perpendicular to a direction along which the patient's breath flows. Desirably, the polyimide may be in the center of the channel. That is, it is desirable that the first sensing film 1 is perpendicular to a lengthwise direction of the first output channel 62, and the direction where the wider surface (on which the polyimide 31 is formed) is faced, is perpendicular to a direction in which the patient's breath flows along the channel. The sensing film 2 is formed perpendicular to a lengthwise direction of the second output channel 64 (or perpendicular to a direction along which the patient's breath flows), and the third to sixth sensing films 66, 68, 70, 72 are formed in the same manner. However, it is not strictly limited that the sensing films are in perpendicular relationships. That is, the sensing films may not be formed in the abovementioned perpendicular relationships, but intead formed close to a perpendicular relationship, as long as a majority of the patient's breath can pass the polyimide 31.

[34] The operation of the SAW sensor for detecting lung cancer according to the embodiments of the present invention will be explained below.

[35] As a patient or a person suspected with lung cancer breathes out through the air holes

14 of the sensor illustrated in FIG. 1, his breath is introduced into the sensor cap 12, and blows toward the first to sixth sensing films 1, 2, 3, 4, 5, 6 through the openings 23, 21 of the SAW signal generating unit 30. When the patient's breath blows past the first to sixth sensing films 1, 2, 3, 4, 5, 6, the VOC of the breath is adsorbed in the polyimides 31 of the first to sixth sensing films 1, 2, 3, 4, 5, 6, thereby causing change of SAW signal which is sent from the first to sixth input electrodes 36, 38, 40, 42, 44, 46 to the first to sixth output electrodes 33, 35, 37, 39, 41, 43 through the first to sixth substrates 50, 52, 54, 56, 58, 60. The degree of the SAW signal's change is determined based on the type of the VOC and the amount of the absorption. Referring to FIG. 4, the signal is changed and output through the first to sixth output electrodes 33, 35, 37, 39, 41, 43, passed through the signal transferring unit 84, and sent to the SAW signal reader 100 through the cable 80. Accordingly, the SAW signal reader 100 reads in SAW signal, compares the signal with prestored data, performs necessary algorithms, and indicates on a display 200 the result of reading such as presence or absence of lung cancer or cancer development. [36] Referring to FIG. 1, since the lengthwise directions of the first to sixth sensing films

1, 2, 3, 4, 5, 6 are perpendicular to a direction in which the patient's breath blows, and the sensing films 1, 2, 3, 4, 5, 6 are parallel to each other, almost same amount of the patient's breath goes past the polyimides 31 of the sensing films 1, 2, 3, 4, 5, 6, and as a result, each of the polyimides 31 adsorbs a similar amount of VOC from the patient's breath. Furthermore, since the air does not directly hit the upper portions of the sensing films 1, 2, 3, 4, 5, 6, the sensing films 1, 2, 3, 4, 5, 6 are less affected by the pressure of the flow of breath. As a result, accurate measurement can be obtained, since the sensing films 1, 2, 3, 4, 5, 6, which are highly sensitive, are not affected by the pressure.

[37] Furthermore, referring to the second embodiment mainly illustrated in FIG. 3, since the channels for the patient's breath are isolated from each other and arranged in a radial alignment, and since the sensing films 1, 2, 3, 4, 5, 6 are formed in a manner in which the polyimides 31 are placed in the center of each of the output channels 62, 64, 66, 68, 70, 72, most of the patient's breath can pass the polyimides 31 of the first to sixth sensing films 1, 2 ,3, 4, 5, 6, almost without a loss. As a result, more accurate measurement can be obtained.

[38] Furthermore, referring to FIGS. 2 and 3, since the sensing films 1, 2, 3, 4, 5, 6 are formed on the separate substrates 50, 52, 54, 56, 58, 60 which are spaced apart from each other, SAW signals generated from the sensing films 1, 2, 3, 4, 5, 6 suffer less interferences, and as a result, highly reliable measurement can be obtained.

Claims

[1] A surface acoustic wave (SAW) sensor for detecting lung cancer, comprising: a base cap; a sensor cap removably connected to the base cap, the sensor cap on which an air hole is formed; a SAW signal generating unit formed inside the sensor cap; and a SAW signal transferring unit connected to the SAW signal generating unit to transfer generated SAW signal, wherein the SAW generating unit comprises at least six sensing films of different frequencies, in which each of the six sensing films comprises a substrate on which an electrode and a polyimide are coated.

[2] The SAW sensor of claim 1 , wherein the sensing films are formed in a manner in which a direction in which upper surfaces are faced is perpendicular to a direction in which a patient's breath flows in, so that the patient's breath does not directly collide against wider surfaces of the sensing films.

[3] The SAW sensor of claim 2, wherein the SAW signal generating unit comprises a jig member having a jig base in which output channels are formed radially, and the sensing films are arranged radially on the output channels at predetermiend intervals.

[4] The SAW sensor of claim 2, wherein the sening films are parallel to each other at predetermined intervals.

[5] The SAW sensor of claim 1, wherein the sensing films each comprises a substrate, an input electrode and an output electrode coated on the substrate, and a polyimide formed between the input and output electrodes.

[6] The SAW sensor of one of claims 1 to 5, wherein the SAW signal genenerating unit comprises six sensing films, in which each of the six sensing films has a frequency of 100 MHz, 200 MHz, 300 MHz, 400 MHz, 500 MHz, and 600 MHz.