JP6713638B2 - Surface characteristic measuring method, surface characteristic measuring device, and surface characteristic measuring program - Google Patents
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Description
本発明は、表面特性の測定に関し、特に、超音波を利用した物体表面・表層の物理特性の測定に関する。 The present invention relates to measurement of surface characteristics, and more particularly to measurement of physical characteristics of an object surface/surface layer using ultrasonic waves.
物体表面・表層の特性の評価は様々な分野で有用である。たとえば、生体の場合、生体の表面・表層に存在するのは皮膚であり、皮膚の特性である肌質を把握することで、肌質に応じたスキンケアを行って健康な皮膚を維持することができる。美容・化粧品の分野では、肌質は一般に美容技術者による問診などを通して評価されている。また、計測機器を使用して皮膚の力学特性(肌の柔軟性、弾力性など)や光学特性(肌のつや透明感など)を測定し、肌の状態や機能を客観的に評価することも行われている。 The evaluation of the properties of the object surface/surface layer is useful in various fields. For example, in the case of a living body, it is the skin that exists on the surface/surface layer of the living body, and by grasping the skin quality that is a characteristic of the skin, it is possible to perform skin care according to the skin quality and maintain healthy skin. it can. In the field of beauty/cosmetics, skin quality is generally evaluated through interviews with beauty engineers. It is also possible to objectively evaluate the condition and function of the skin by measuring mechanical properties of the skin (skin flexibility, elasticity, etc.) and optical properties (skin gloss and transparency, etc.) using a measuring device. Has been done.
非侵襲計測機器を用いた従来の皮膚の物理特性の測定は、皮膚を表層から一定の条件で応力を負荷したり、一定の変位を加えた上で反力や応答を測定する方法が一般的であり、その値をもって、皮膚全体の物理特性の評価値として検出してきた。しかし皮膚を構成する各層(角層、表皮、真皮、皮下組織)の寄与がすべて含まれた値として特性値が検出されている。皮膚を構成する各層には、それぞれの役割、機能があるので、各層を個別に測定、評価できることが望ましい。 Conventional measurement of physical properties of the skin using non-invasive measuring equipment is generally a method of applying stress to the skin from the surface layer under certain conditions or measuring reaction force and response after applying certain displacement. That value has been detected as an evaluation value of the physical properties of the entire skin. However, the characteristic value is detected as a value that includes all the contributions of each layer (stratum corneum, epidermis, dermis, subcutaneous tissue) constituting the skin. Since each layer constituting the skin has its own role and function, it is desirable that each layer can be individually measured and evaluated.
特に、皮膚の最外層にある角層は、生命活動の維持に必要なバリア機能や保湿機能を備えていることから、その特性値の正確な測定は、医療、製薬の分野で重要な課題である。また、スキンケアの訴求対象が薬事的には角層に限定されていることから、角層のみの特性評価は、美容・化粧品の分野でも有意義である。しかし、従来の応力・変位付加型の非侵襲皮膚計測機器では、角層のみの物理特性を測定する事はできなかった。皮膚の各層別の物理特性値を測定したい場合は、非侵襲的な手法ではなく、生検などの切除皮膚片を用いた侵襲的な手法を用いる必要があった。たとえば特許文献1の方法は、皮膚の断層標本を作製することで皮膚断面の音速分布を測定する方法であり、皮膚断層の各層別の音速、つまり体積弾性率を指標とする物理特性値で皮膚の各部位におけるかたさを計測することが可能である。 In particular, the stratum corneum, which is the outermost layer of the skin, has a barrier function and a moisturizing function necessary for maintaining vital activity, so accurate measurement of its characteristic values is an important issue in the fields of medicine and pharmaceuticals. is there. Further, since the object of appeal of skin care is limited to the stratum corneum in terms of pharmaceuticals, the evaluation of characteristics of the stratum corneum alone is also meaningful in the field of beauty and cosmetics. However, the conventional stress/displacement-type non-invasive skin measuring device cannot measure the physical properties of only the horny layer. When it is desired to measure the physical property values of each layer of skin, it is necessary to use an invasive method using excised skin pieces such as biopsy, instead of the non-invasive method. For example, the method of Patent Document 1 is a method of measuring the sound velocity distribution of the skin cross section by preparing a skin tomographic sample, and the sound velocity of each layer of the skin tomographic layer, that is, the physical characteristic value using the bulk elastic modulus as an index. It is possible to measure the hardness of each part of.
図1は、従来法で切り取った皮膚断面切片の音速分布画像である。図1の(A)は若年者の頬の皮膚切片、図1の(B)は高齢者の頬の皮膚断面切片である。図1に掲載するように、紫外線露光部皮膚(頬)においては、最表層の角層の音速は高く(かたく)なる一方で、真皮中層の音速つまり体積弾性率が低下する(やわらかくなる)といった複合的な変化が見られることが分かっている。こういった複合的な変化が見られる測定対象については、従来の応力・変位付加型の非侵襲皮膚計測機器では、表面・表層の物理特性のみを評価することは不可能である。実際に紫外線露光部皮膚(頬)を非侵襲皮膚計測機器として汎用される、吸引法による皮膚粘弾性測定装置(皮膚を一定の圧力で減圧した際に浮き上がる皮膚の高さを評価する方法)で評価すると、真皮が柔らかくなる影響が大きく反映されてしまい、表面・表層がかたくなる現象を捉えることはできていない。 FIG. 1 is a sound velocity distribution image of a skin cross section cut by a conventional method. FIG. 1(A) is a young cheek skin section, and FIG. 1(B) is an elderly cheek skin section. As shown in Fig. 1, in the skin (cheek) exposed to ultraviolet rays, the sound velocity of the outermost stratum corneum becomes higher (harder), while the sound velocity of the middle dermis, that is, volume elastic modulus, decreases (becomes softer). It is known that complex changes can be seen. With respect to the measurement target that shows such complex changes, it is impossible to evaluate only the physical properties of the surface/surface layer with the conventional stress/displacement-added non-invasive skin measurement device. With the skin viscoelasticity measuring device by the suction method (a method to evaluate the height of the skin that rises when the skin is decompressed at a certain pressure), which is actually used as a non-invasive skin measurement device for the skin exposed to the UV When evaluated, the effect of softening the dermis is largely reflected, and it is not possible to capture the phenomenon that the surface/surface layer becomes hard.
なお、従来の応力・変位付加による非侵襲の皮膚計測機器とは別に、近年、超音波を用いて、非侵襲的に皮膚の異なる深さでのかたさ情報を得る手法が提案されている(特許文献2参照)。この方法は、異なる周波数成分を含む超音波を皮膚に照射して、反射波の音響インピーダンスを計算することで、異なる深さにある複数の層の情報を測定する方法で、皮膚内部からの情報と、皮膚表面・表層の情報と切り分けることが可能で、皮膚表面・表層のみの物理特性を得ることが可能になっている。 In addition to the conventional non-invasive skin measuring device by applying stress/displacement, in recent years, a method of non-invasively obtaining hardness information at different depths of the skin has been proposed (Patent Reference 2). This method irradiates the skin with ultrasonic waves containing different frequency components and calculates the acoustic impedance of the reflected wave to measure the information of multiple layers at different depths. It is possible to separate from the information of the skin surface/surface layer, and it is possible to obtain the physical properties of only the skin surface/surface layer.
上述した特許文献2の手法は、プローブの先端を皮膚に押し当て、皮膚から異なる周波数の反射波を受信し、測定することで、皮膚を構成する各層の情報を取得している。 In the method of Patent Document 2 described above, the tip of the probe is pressed against the skin, the reflected waves of different frequencies are received from the skin, and the measurement is performed to acquire the information of each layer constituting the skin.
しかし、この手法では皮膚表面に存在する細かい凹凸(皮溝と皮丘)の影響が考慮されていない。実際にはプローブの先端を皮膚に押し当てても、皮溝の部分はプローブの先端面に接触しづらく、接触していない部分では角層の正確な音響インピーダンスを取得することができない。この問題点は、皮膚測定に限らず、歯片や爪などの生体の表面測定や、微細な凹凸が存在する有機または無機の表面・表層の測定にも当てはまる。 However, this method does not consider the effects of fine irregularities (skin grooves and crests) present on the skin surface. Actually, even if the tip of the probe is pressed against the skin, the skin groove portion is hard to contact the tip surface of the probe, and the accurate acoustic impedance of the stratum corneum cannot be acquired in the portion which is not in contact. This problem applies not only to skin measurement, but also to surface measurement of living bodies such as teeth and nails, and measurement of organic or inorganic surface/surface layer having fine irregularities.
そこで、本発明は、物質の表面特性を精度良く評価することのできる表面特性測定の手法と構成を提供することを目的とする。 Therefore, it is an object of the present invention to provide a surface property measuring method and a structure capable of accurately evaluating the surface property of a substance.
上記課題を解決するために、測定対象物からの反射波形と、参照物質(具体的には超音波伝達媒体(カプラント)として用いる純水など)からの反射波形である参照波形との間の相互相関関数の最大点で反射成分を抽出し、この反射成分と参照波形との比較結果に応じて表面特性を表わす音響インピーダンスを算出する。 In order to solve the above-mentioned problems, mutual interaction between a reflection waveform from a measurement object and a reference waveform which is a reflection waveform from a reference substance (specifically, pure water used as an ultrasonic transmission medium (couplant)) The reflection component is extracted at the maximum point of the correlation function, and the acoustic impedance representing the surface characteristic is calculated according to the comparison result of this reflection component and the reference waveform.
具体的には、表面特性測定方法は、
測定対象物に超音波を照射して前記測定対象物からの反射信号を取得し、
測定装置にて、前記測定対象物からの反射信号と、あらかじめ取得した参照物質からの参照反射信号との相互相関関数の最大値を計算し、
前記相互相関関数の最大値を用いて界面での反射成分を計算し、
前記反射成分と前記参照反射信号の比較結果に応じて、前記測定対象物の音響インピーダンスと前記参照物質の音響インピーダンスのいずれか一方を測定値として出力する。
Specifically, the surface characteristic measuring method is
Obtain a reflection signal from the measurement object by irradiating the measurement object with ultrasonic waves,
In the measurement device, the maximum value of the cross-correlation function of the reflection signal from the measurement object and the reference reflection signal from the reference material previously acquired,
Calculating the reflection component at the interface using the maximum value of the cross-correlation function,
Either the acoustic impedance of the measurement object or the acoustic impedance of the reference material is output as a measurement value according to the comparison result of the reflection component and the reference reflection signal.
上記手法により、物質の表面特性を精度良く測定することができる。 By the above method, the surface characteristics of the substance can be measured with high accuracy.
以下、図面を参照して本発明の実施の形態を説明する。 Hereinafter, embodiments of the present invention will be described with reference to the drawings.
図2は、実施形態の表面特性測定装置1の概略図である。表面特性測定装置1は、プローブ2と、情報処理装置3を有する。プローブ2は、先端に超音波が透過する音響窓5を有する。音響窓5の測定対象と接する材料は、測定対象とは異なる既知の音響インピーダンスを有し、超音波を通過しうる硬質の材料(たとえば硬質の樹脂等)で形成される。 FIG. 2 is a schematic diagram of the surface characteristic measuring device 1 of the embodiment. The surface characteristic measuring device 1 has a probe 2 and an information processing device 3. The probe 2 has an acoustic window 5 that allows ultrasonic waves to pass therethrough. The material of the acoustic window 5 that is in contact with the measurement target has a known acoustic impedance different from that of the measurement target and is formed of a hard material (for example, a hard resin or the like) that can pass ultrasonic waves.
プローブ2は、情報処理装置3と通信可能である。図2の例ではケーブル4で接続されているが、無線接続されていてもよい。プローブ2の音響窓5からは、二次元走査されて送信される超音波が測定対象物に照射され、その反射波はプローブ2で受信され、電気信号に変換されて出力される。受信された反射波には、測定対象物に関する情報が含まれている。 The probe 2 can communicate with the information processing device 3. In the example of FIG. 2, the cable 4 is used for connection, but wireless connection may be used. From the acoustic window 5 of the probe 2, an ultrasonic wave that is two-dimensionally scanned and transmitted is applied to the measurement object, and the reflected wave is received by the probe 2, converted into an electric signal, and output. The received reflected wave contains information about the measurement target.
プローブ2は手で把持可能で、たとえば皮膚を計測する場合、手で持ち、被験者の皮膚に直接当てることもできる。また、体の動きに影響を受けることなく精度の高い計測を行いたい場合には、プローブ2を固定したり、プローブ2と頬を両面テープで固定して使用することも可能である。 The probe 2 can be held by hand, and when measuring the skin, for example, it can be held by hand and directly applied to the skin of the subject. Further, in order to perform highly accurate measurement without being affected by the movement of the body, it is possible to fix the probe 2 or fix the probe 2 and the cheek with double-sided tape before use.
情報処理装置3は、プローブ2で受信された反射波を解析して、測定対象物の表面特性を検出する。情報処理装置3としては、ノート型コンピュータ、タブレット端末等、演算処理機能と表示機能を有する任意の情報処理装置を用いることができる。実施形態では、情報処理装置3は、測定対象物からの反射波形と、参照波形との相互相関の最大をとることで、測定対象物の内部成分からの反射波形への干渉、および表面形態の凹凸の影響(音響窓への接触、非接触による反射波形への影響)を除去して、正確な表面・表層の音響インピーダンスを抽出する。たとえば、測定対象物が皮膚であるときは、皮膚内部の表皮や真皮からの干渉や、表面形状(きめ、しわなど)の凹凸の影響を除外した、正確な皮膚表層(角層)のかたさや弾性などの物理特性情報を取得する。測定対象物が歯であるときは、内部のセメント質や象牙質の影響、および表面形状(粗さ)の凹凸の影響を除外した、正確な表面のエナメル質のかたさなどの情報を測定する。測定対象が多層フィルムや多層コーティング材の場合は、内部の積層の影響や、表面形状の凹凸の影響を低減して、最表層のかたさや弾性などの情報を測定する。 The information processing device 3 analyzes the reflected wave received by the probe 2 to detect the surface characteristics of the measurement target. As the information processing device 3, any information processing device having an arithmetic processing function and a display function, such as a notebook computer and a tablet terminal, can be used. In the embodiment, the information processing device 3 obtains the maximum cross-correlation between the reflection waveform from the measurement target and the reference waveform, thereby interfering with the reflection waveform from the internal component of the measurement target and the surface morphology. Accurate acoustic impedance of the surface and surface layer is extracted by removing the effect of unevenness (effect on the reflected waveform due to contact with and non-contact with the acoustic window). For example, when the object to be measured is skin, it is possible to accurately measure the hardness of the skin surface layer (corneal layer) excluding the interference from the epidermis and dermis inside the skin and the influence of unevenness of the surface shape (texture, wrinkles, etc.) Acquire physical property information such as elasticity. When the object to be measured is a tooth, information such as the exact hardness of the enamel on the surface is measured, excluding the effects of the internal cementum and dentin, and the effects of unevenness of the surface shape (roughness). When the measurement target is a multi-layer film or a multi-layer coating material, the influence of the lamination inside and the influence of the unevenness of the surface shape are reduced, and the information such as the hardness and elasticity of the outermost layer is measured.
図3は、図2の表面特性測定装置1のブロック図である。プローブ2は、超音波センサ回路21と、インタフェース(I/F)27を有する。インタフェース27は、上述のように無線インタフェースであってもよいし、物理的なインタフェースであってもよい。 FIG. 3 is a block diagram of the surface characteristic measuring device 1 of FIG. The probe 2 has an ultrasonic sensor circuit 21 and an interface (I/F) 27. The interface 27 may be a wireless interface as described above or a physical interface.
超音波センサ回路21は、送信部22と、受信部24と、送受波を分離する送受波分離回路25と、トランスデューサ28を有する。送信部22は、パルス発生回路23を有する。パルス発生回路23は、所定のタイミングで駆動パルスを生成する。送信部22は、送受波分離回路25を介して、駆動パルスをトランスデューサ28に印加する。トランスデューサ28は、パルス(電気)信号を機械的振動に変換して超音波を出力する。 The ultrasonic sensor circuit 21 includes a transmission unit 22, a reception unit 24, a transmission/reception wave separation circuit 25 for separating transmission/reception waves, and a transducer 28. The transmission unit 22 has a pulse generation circuit 23. The pulse generation circuit 23 generates a drive pulse at a predetermined timing. The transmitter 22 applies a drive pulse to the transducer 28 via the transmission/reception wave separation circuit 25. The transducer 28 converts the pulse (electrical) signal into mechanical vibration and outputs ultrasonic waves.
トランスデューサ28は、測定対象物から反射された反射波を受け取り、反射波を電気信号に変換する。受信電気信号は、送受波分離回路25により受信部24に供給される。受信部24は、アナログ電気信号を検波し、アナログ/デジタルコンバータ(ADC)でデジタル信号に変換する。デジタル信号(反射波)は、インタフェース27を介して、情報処理装置3に送信される。 The transducer 28 receives the reflected wave reflected from the measurement object and converts the reflected wave into an electric signal. The received electric signal is supplied to the reception unit 24 by the transmission/reception wave separation circuit 25. The receiving unit 24 detects an analog electric signal and converts it into a digital signal by an analog/digital converter (ADC). The digital signal (reflected wave) is transmitted to the information processing device 3 via the interface 27.
情報処理装置3は、CPU31、インタフェース(I/F)32、メモリ33、DSP(Digital Signal Processor:デジタル信号プロセッサ)34、入力装置35、表示装置36、及び記憶装置37を有する。プローブ2から送信される反射波信号は、インタフェース32を介してDSP34に入力され、DSP34で信号処理される。 The information processing device 3 includes a CPU 31, an interface (I/F) 32, a memory 33, a DSP (Digital Signal Processor) 34, an input device 35, a display device 36, and a storage device 37. The reflected wave signal transmitted from the probe 2 is input to the DSP 34 via the interface 32 and processed by the DSP 34.
入力装置35は、タッチパネル、マウス、キーボード等の入力ユーザインタフェースである。表示装置36は、液晶、プラズマ、有機EL(electroluminescence)等のモニタディスプレイである。記憶装置37は、磁気ディスク装置、光ディスク装置等のハードディスクドライブであり、各種プログラムやデータを格納する。メモリ33は、RAM(ランダムアクセスメモリ)やROM(リードオンリーメモリ)を含み、超音波測定のためにあらかじめ取得された参照物質の反射波形とその音響インピーダンスを保存する。 The input device 35 is an input user interface such as a touch panel, a mouse, a keyboard. The display device 36 is a monitor display of liquid crystal, plasma, organic EL (electroluminescence), or the like. The storage device 37 is a hard disk drive such as a magnetic disk device or an optical disk device, and stores various programs and data. The memory 33 includes a RAM (random access memory) and a ROM (read only memory), and stores the reflection waveform of the reference substance and its acoustic impedance that are acquired in advance for ultrasonic measurement.
DSP34は、測定対象物からの反射波形と参照物質からの反射波形の最大の相互相関に基づいて、測定対象物の音響インピーダンスから表面特性を決定する。実施形態では、DSP34が超音波反射波の信号処理を行うものとして説明するが、後述する表面特性測定プログラムを用いる場合は、CPU31が記憶装置37に格納された表面特性測定プログラムを読み出して信号解析を実行してもよい。 The DSP 34 determines the surface characteristics from the acoustic impedance of the measurement object based on the maximum cross-correlation between the reflection waveform from the measurement object and the reflection waveform from the reference material. In the embodiment, the DSP 34 is described as performing signal processing of ultrasonic reflected waves, but when using a surface characteristic measurement program described later, the CPU 31 reads the surface characteristic measurement program stored in the storage device 37 and performs signal analysis. May be executed.
図4は、超音波の反射状態を示す図である。たとえば、皮膚表面の角層51を測定する場合を考える。皮膚は、表皮52、真皮53、皮下組織(不図示)と多層で形成されている。表皮52の最表面が角層51である。皮膚の表面には細かい凹凸、すなわち皮溝55と皮丘56がある。皮溝55は、肌の表面を微細な皮丘56に区画する溝であるが、皮溝が深く粗くなったしわや毛穴の部分も皮溝55に含まれる。プローブ2の音響窓5を皮膚に押し当てた場合でも、実際は、皮溝55は音響窓5と接触していない。音響窓5と皮溝55の間には、水、ゲル等のカプラント(超音波結合媒体)10が存在する。超音波は空気層でほぼ100%反射されるため、超音波測定では、通常はカプラント10を介在させて、トランスデューサ28と皮膚の間の音エネルギーの伝達を確保する。 FIG. 4 is a diagram showing a reflection state of ultrasonic waves. For example, consider the case of measuring the stratum corneum 51 on the skin surface. The skin is made up of multiple layers including an epidermis 52, a dermis 53, and a subcutaneous tissue (not shown). The outermost surface of the skin 52 is the horny layer 51. The surface of the skin has fine irregularities, that is, skin grooves 55 and cuticles 56. The skin groove 55 is a groove that divides the surface of the skin into fine skin ridges 56, but the skin groove 55 also includes wrinkles and pores where the skin groove is deep and rough. Even when the acoustic window 5 of the probe 2 is pressed against the skin, the skin groove 55 is not actually in contact with the acoustic window 5. A couplant (ultrasonic coupling medium) 10 such as water or gel exists between the acoustic window 5 and the skin groove 55. Since ultrasonic waves are almost 100% reflected in the air layer, ultrasonic measurements typically involve the couplant 10 to ensure the transfer of sound energy between the transducer 28 and the skin.
皮溝55の部分では、音響窓5は角層51と直接接触できず、カプラント10に接触する。そのため、従来法では角層51の正確な音響インピーダンスを取得することができない。実際は皮溝55であっても、皮丘56として処理されるからである。微細な凹凸のある測定対象物の表面特性を測定する場合は、凸部(たとえば皮丘56)で取得される音響インピーダンスと凹部(たとえば皮溝55)での音響インピーダンスを区別して評価する必要がある。 In the portion of the skin groove 55, the acoustic window 5 cannot directly contact the stratum corneum 51 but contacts the couplant 10. Therefore, the conventional method cannot acquire the accurate acoustic impedance of the stratum corneum 51. This is because, in reality, even the skin groove 55 is processed as the skin crest 56. When measuring the surface characteristics of the measuring object having fine irregularities, it is necessary to distinguish and evaluate the acoustic impedance acquired at the convex portion (for example, the crest 56) and the acoustic impedance at the concave portion (for example, the skin groove 55). is there.
図5は、実施形態の原理を説明する図である。実施形態では、あらかじめ参照物質としてのカプラント10からの反射波形を表わす参照信号と、その音響インピーダンスを取得しておく。測定対象物(たとえば皮膚)で反射された超音波の反射波形と、参照波形との最大の相互相関をとることで、表面の角層51よりも深い層からの反射成分を除去して、音響窓5の界面での反射情報を抽出する。これを参照信号と比較することで、音響窓5が直接皮膚に接触しているのか、カプラント10が入り込んだ皮溝55の部分なのかを判断する。 FIG. 5 is a diagram illustrating the principle of the embodiment. In the embodiment, the reference signal representing the reflected waveform from the couplant 10 as the reference substance and its acoustic impedance are acquired in advance. By taking the maximum cross-correlation between the reflected waveform of the ultrasonic wave reflected by the measurement object (for example, skin) and the reference waveform, the reflected component from the layer deeper than the horny layer 51 on the surface is removed, and the acoustic The reflection information at the interface of the window 5 is extracted. By comparing this with the reference signal, it is determined whether the acoustic window 5 is in direct contact with the skin or the portion of the skin groove 55 in which the couplant 10 has entered.
音響窓5が角層51と直接接触している部分では、反射波形st1が得られる。最大ピークは、角層51と音響窓5の界面で反射された成分である。最大ピークの後ろに現れる複数の小さなピークは、角層51よりも深い部分で反射された成分である。たとえば角層51と表皮52の界面、表皮52と真皮53(図4参照)の界面、真皮53と皮下組織の界面などで反射された成分である。 In the portion where the acoustic window 5 is in direct contact with the stratum corneum 51, the reflected waveform st1 is obtained. The maximum peak is the component reflected at the interface between the stratum corneum 51 and the acoustic window 5. A plurality of small peaks appearing after the maximum peak are components reflected in a portion deeper than the stratum corneum 51. For example, it is a component reflected at the interface between the stratum corneum 51 and the epidermis 52, the interface between the epidermis 52 and the dermis 53 (see FIG. 4), the interface between the dermis 53 and the subcutaneous tissue, and the like.
他方、音響窓5が角層51と接触しない部分では、反射波形st1とは異なる反射波形st2が得られる。これは、音響窓5とカプラント10の界面で反射された成分と、カプラント10と角層51の界面で反射された成分を含む、さらに、反射波形st1と同様に、皮膚のさらに深い部分からの反射成分も含む。 On the other hand, in the portion where the acoustic window 5 does not contact the horny layer 51, a reflection waveform st2 different from the reflection waveform st1 is obtained. This includes a component reflected at the interface between the acoustic window 5 and the couplant 10 and a component reflected at the interface between the couplant 10 and the stratum corneum 51. Furthermore, similar to the reflection waveform st1, from a deeper portion of the skin. Also includes a reflection component.
カプラント10からの反射波の参照波形を取得するために、音響窓5または音響窓5と同質、同じ厚さの基板をカプラント10のみに接触させ、音響窓5とカプラント10の界面からの反射波を取得しておく。これが参照波srである。 In order to obtain the reference waveform of the reflected wave from the couplant 10, the acoustic window 5 or a substrate having the same quality and the same thickness as the acoustic window 5 is contacted only with the couplant 10, and the reflected wave from the interface between the acoustic window 5 and the couplant 10 is obtained. To get. This is the reference wave sr.
図6は、相互相関関数を説明する図である。実施形態では、測定された反射波と参照波のそれぞれのフーリエ変換の相互相関関数を計算するが、図6では説明の便宜上、フーリエ変換前の時間領域での波形で相互相関関数を説明する。 FIG. 6 is a diagram illustrating a cross-correlation function. In the embodiment, the cross-correlation function of each Fourier transform of the measured reflected wave and the reference wave is calculated, but in FIG. 6, the cross-correlation function is described with a waveform in the time domain before the Fourier transform for convenience of description.
相互相関関数は、測定対象物(ターゲット)からの反射波stと参照波srの積を積分してから、それぞれの波形の実効値(rms:二乗平均平方根)の積で除算した値であり、−1から1の値をとる。デジタルサンプリングされた波形を多次元ベクトルとすると、ターゲットからの反射波stと参照波srの相関は、ベクトルの内積を絶対値の積で除算した値となる。波形の時間差を変化させながら相関係数を計算した結果が、相互相関関数となる。 The cross-correlation function is a value obtained by integrating the product of the reflected wave st from the measurement target (target) and the reference wave sr, and then dividing by the product of the effective value (rms: root mean square) of each waveform, It takes a value from -1 to 1. When the digitally sampled waveform is a multidimensional vector, the correlation between the reflected wave st from the target and the reference wave sr is a value obtained by dividing the inner product of the vector by the product of absolute values. The cross-correlation function is the result of calculating the correlation coefficient while changing the time difference between the waveforms.
参照物質からの参照波srも、ターゲットからの反射波stも、音響窓5との界面からの反射が最も強い。音響窓5との界面よりも後ろ(奥)からの反射は、音響窓5の界面からの反射に比較して小さい。したがって、ターゲットからの反射波stと、参照波srとの相互相関関数が最大となる点が、音響窓5との界面の位置を示す。このときの相互相関関数をRmaxとする。 Both the reference wave sr from the reference material and the reflected wave st from the target are most strongly reflected from the interface with the acoustic window 5. The reflection from the back (back) of the interface with the acoustic window 5 is smaller than the reflection from the interface of the acoustic window 5. Therefore, the point where the cross-correlation function between the reflected wave st from the target and the reference wave sr becomes maximum indicates the position of the interface with the acoustic window 5. The cross-correlation function at this time is Rmax.
相互相関関数の最大値をとることで、音響窓5の界面よりも奥の部分での反射成分を除去する。なお、音響窓5または基板が凸状に湾曲している場合は、図7に於いてRmaxを与える位置にずれが生じる。すなわち、相互相関関数が最大となるときの時間軸上の位置Δtはゼロでなくなる。 By taking the maximum value of the cross-correlation function, the reflection component in the portion deeper than the interface of the acoustic window 5 is removed. When the acoustic window 5 or the substrate is curved in a convex shape, a position where Rmax is given in FIG. 7 is displaced. That is, the position Δt on the time axis when the cross-correlation function becomes maximum is not zero.
測定対象物(ターゲット)からの時間領域の反射波stをフーリエ変換して、周波数領域の反射信号Stを計算する。また、参照波srをフーリエ変換して、周波数領域の参照信号Srを計算する。これらを用いて、相互相関関数が最大となるときの界面における反射成分St(1)の大きさを求める。St(1)は式(1)から計算される。 The reflected wave st in the time domain from the measuring object (target) is Fourier transformed to calculate the reflected signal St in the frequency domain. Further, the reference wave sr is Fourier transformed to calculate the reference signal Sr in the frequency domain. Using these, the magnitude of the reflection component St (1) at the interface when the cross-correlation function becomes maximum is obtained. St (1) is calculated from equation (1).
上述のように、St(1)は、音響窓5が直接物質と接触する界面での反射強度である。St(1)とSrの大きさが等しければ、音響窓5に直接接触するのはカプラント10であり、皮溝55の部分に相当すると判別することができる。この場合は、あらかじめ取得した参照物質(カプラント10)の音響インピーダンスを出力する。なお、本明細書と特許請求の範囲で反射信号と参照信号の大きさが「等しい」というときは、カプラントや音響窓の材質のばらつき、測定条件のばらつき等に起因するわずかな誤差を含むものとする。 As described above, St (1) is the reflection intensity at the interface where the acoustic window 5 directly contacts the substance. If the sizes of St (1) and Sr are equal, it is possible to determine that the couplant 10 is in direct contact with the acoustic window 5 and corresponds to the skin groove 55. In this case, the acoustic impedance of the reference material (couplant 10) acquired in advance is output. In the present specification and claims, when the magnitudes of the reflected signal and the reference signal are “equal to each other,” it includes a slight error due to variations in the materials of the couplant and the acoustic window, variations in the measurement conditions, and the like. ..
St(1)がSrよりも小さい場合は(St(1)<Sr)、音響窓5に直接接触する物質の音響インピーダンスは、参照物質であるカプラント10の音響インピーダンスよりも大きいので、角層51に接していると判別できる。この場合は、式(2)から、角層51の音響インピーダンスを計算する。 When St (1) is smaller than Sr (St (1) <Sr), the acoustic impedance of the substance that is in direct contact with the acoustic window 5 is larger than the acoustic impedance of the couplant 10, which is the reference substance. You can tell that you are in contact with. In this case, the acoustic impedance of the stratum corneum 51 is calculated from the equation (2).
求めた音響インピーダンスを他の力学特性、たとえば体積弾性率に変換してもよい。音響インピーダンスや、変換後の力学特性を画像化することで、皮膚表面の凹凸状態や弾性を視覚的に把握することができる。 The obtained acoustic impedance may be converted into another mechanical characteristic such as bulk modulus. By imaging the acoustic impedance and the mechanical characteristics after conversion, it is possible to visually grasp the unevenness state and elasticity of the skin surface.
図7は、実施形態の表面特性測定方法のフローチャートである。まず、参照物質から反射された成分を表わす参照信号Srとその音響インピーダンスをあらかじめ取得する(S101)。参照物質から反射された参照信号Srと音響インピーダンスは、メモリ33に記憶される。参照物質としては、上述したカプラント10の他、水、ゲルなどを用いてもよい。参照物質からの反射信号(参照信号)Srは、フーリエ変換後の値とする。 FIG. 7 is a flowchart of the surface characteristic measuring method of the embodiment. First, the reference signal Sr representing the component reflected from the reference substance and its acoustic impedance are acquired in advance (S101). The reference signal Sr and the acoustic impedance reflected from the reference material are stored in the memory 33. As the reference substance, water, gel, or the like may be used in addition to Couplant 10 described above. The reflection signal (reference signal) Sr from the reference substance is a value after Fourier transform.
また、測定対象物質(ターゲット)からの反射信号Stを取得する(S102)。この反射信号Stもフーリエ変換後の値である。次に、反射信号Stと参照信号Srの相互相関関数の最大値Rmを計算する(S103)。 Further, the reflection signal St from the measurement object (target) is acquired (S102). This reflection signal St is also a value after Fourier transform. Next, the maximum value Rm of the cross-correlation function of the reflected signal St and the reference signal Sr is calculated (S103).
測定結果と、算出したRmを用いて、音響窓5の界面における反射成分St(1)を計算する(S104)。界面での反射成分St(1)が参照信号Srよりも小さいか否かを判断する(S105)。界面での反射成分St(1)が参照信号Srよりも小さい場合は(S105でYES)音響窓5が測定対象物と実際に接触していることを意味する。この場合は、測定対象物の音響インピーダンスを算出して出力する(S106)。 The reflection component St (1) at the interface of the acoustic window 5 is calculated using the measurement result and the calculated Rm (S104). It is determined whether the reflection component St (1) at the interface is smaller than the reference signal Sr (S105). When the reflection component St (1) at the interface is smaller than the reference signal Sr (YES in S105), it means that the acoustic window 5 is actually in contact with the measurement object. In this case, the acoustic impedance of the measurement object is calculated and output (S106).
界面での反射成分St(1)が参照信号Srよりも小さくない場合は(S105でNO)、音響窓5が直接接触しているのは、参照物質であることを意味する。皮膚表面の場合は、皮溝55に当たる部分を測定していることを意味する。この場合は、参照物質の音響インピーダンスを出力する(S107)。所定の範囲にわたって音響インピーダンスが得られたら、表面特性を評価して(S108)、処理を終了する。 When the reflection component St (1) at the interface is not smaller than the reference signal Sr (NO in S105), it means that the acoustic window 5 is in direct contact with the reference substance. In the case of the skin surface, it means that the portion corresponding to the skin groove 55 is being measured. In this case, the acoustic impedance of the reference material is output (S107). When the acoustic impedance is obtained over the predetermined range, the surface characteristics are evaluated (S108), and the process is ended.
上記の方式により、超音波を用いた表面特性の測定で、表面の微細な凹凸や力学特性を精度良く測定し、評価することができる。たとえば、人の皮膚表面の評価としては、きめの細かさ、なめらかさ、弾性等から何十歳代の皮膚状態に相当するかを評価することができる。 With the above method, it is possible to accurately measure and evaluate the fine irregularities and mechanical properties of the surface by measuring the surface properties using ultrasonic waves. For example, as the evaluation of the skin surface of a person, it is possible to evaluate whether it corresponds to the skin condition of several decades from the viewpoint of fineness of texture, smoothness, elasticity and the like.
図8は、ターゲットからの反射波と参照波の相互相関を用いない場合の生体ヒト皮膚の超音波画像と、X−X'ラインでの音響インピーダンスを示す。画像の横軸は長さ(μm)、縦軸は音響インピーダンス(Pa・s/m3)である。 FIG. 8 shows an ultrasonic image of living human skin in the case where the cross-correlation between the reflected wave from the target and the reference wave is not used, and the acoustic impedance at the line XX′. The horizontal axis of the image is the length (μm), and the vertical axis is the acoustic impedance (Pa·s/m 3 ).
図9は、図8と同じサンプルに対して、上述した実施形態の手法を適用したときの超音波画像と、X−X'ラインでの音響インピーダンスを示す。 FIG. 9 shows an ultrasonic image when the method of the above-described embodiment is applied to the same sample as that in FIG. 8 and acoustic impedance at the line XX′.
図8と図9はともに、健常な20代男性の前腕内側(屈側)における皮膚の2次元プロファイルの音響インピーダンス画像を示している。皮膚は、洗浄後に一定時間乾燥させた後に測定した。測定には、40〜120MHzのトランスデューサ―を用い、カプラントには超純水、皮膚を接触させる基板にはアクリル板を用いた。最も表面で反射される波長に焦点を合わせ、200×200ピクセルで画像を取得した。 8 and 9 both show acoustic impedance images of a two-dimensional profile of the skin on the inside of the forearm (flexion side) of a healthy male in his 20s. The skin was measured after being washed and dried for a certain period of time. For the measurement, a transducer of 40 to 120 MHz was used, ultrapure water was used for couplant, and an acrylic plate was used for the substrate to contact the skin. Images were acquired at 200 x 200 pixels, focusing on the wavelengths most reflected at the surface.
図8の従来法では、X−X'ライン上のA点とB点で、内部の層からの反射が干渉となって、低い値になっている。これに対し、図9の方法では、内部からの反射成分を除去して、角層51のみの値が算出されている。このように、実施形態の方法によると、表面凹凸情報を正確に取得することができる。 In the conventional method of FIG. 8, the reflection from the internal layer becomes an interference at points A and B on the line XX′, which is a low value. On the other hand, in the method of FIG. 9, the reflection component from the inside is removed and the value of only the horny layer 51 is calculated. As described above, according to the method of the embodiment, the surface unevenness information can be accurately acquired.
図10は、取得した音響インピーダンスを画像情報として表示するときの処理フローを示す。この処理も、情報処理装置3のDSP34、またはCPU31で行うことができる。図7と同じ工程には同じ符号を付けて説明する。まず、参照物質からの反射信号(フーリエ変換信号)Srとその音響インピーダンスをあらかじめ取得する(S101)。超音波を測定対象物に対して相対的に走査する際の、測定点の座標データを取得する(S201)。相対的な走査は、固定の測定対象物に対してプローブ2を走査してもよいし、超音波センサ回路21を固定とし、サンプルを保持するステージを2次元駆動してもよい。 FIG. 10 shows a processing flow when displaying the acquired acoustic impedance as image information. This processing can also be performed by the DSP 34 of the information processing device 3 or the CPU 31. The same steps as those in FIG. 7 will be described with the same reference numerals. First, the reflection signal (Fourier transform signal) Sr from the reference substance and its acoustic impedance are acquired in advance (S101). The coordinate data of the measurement point when the ultrasonic wave is relatively scanned with respect to the measurement object is acquired (S201). In the relative scanning, the probe 2 may be scanned with respect to a fixed measurement target, or the ultrasonic sensor circuit 21 may be fixed and the stage holding the sample may be two-dimensionally driven.
次に、各測定点での音響インピーダンスを取得する(S202)。音響インピーダンスの取得は、図7のS102〜S107のように、フーリエ変換した参照信号とターゲットからの反射信号の相互相関関数の最大に基づく界面反射強度と参照信号強度の比較により、ターゲットの音響インピーダンスまたは参照物質の音響インピーダンスが取得される。音響インピーダンスに応じた階調あるいは色で画像データを生成する(S203)。 Next, the acoustic impedance at each measurement point is acquired (S202). The acoustic impedance is acquired by comparing the interface reflection intensity and the reference signal intensity based on the maximum of the cross-correlation function of the Fourier-transformed reference signal and the reflection signal from the target, as in S102 to S107 of FIG. Alternatively, the acoustic impedance of the reference substance is acquired. Image data is generated with gradation or color according to the acoustic impedance (S203).
他の測定点があるか否かを判断し(S204)、他の測定点がある場合は(S204でYES)、S201〜S203を繰り返す。すべての測定点についてS201〜S203の処理を完了すると(S204でYES)、画像を表示する(S205)。 It is determined whether there is another measurement point (S204), and if there is another measurement point (YES in S204), S201 to S203 are repeated. When the processes of S201 to S203 are completed for all the measurement points (YES in S204), the image is displayed (S205).
上記のフローで、いったんすべての測定点について、反射波とそのフーリエ変換値を座標値と対応づけてメモリ33に記憶した後に、各座標点での音響インピーダンスを計算してもよい。この場合も、すべての座標点での画像データが生成されたなら、表示装置36に表示される。また、音響インピーダンスを別の力学特性に変換し、変換値に応じた階調または色で表示してもよい。 In the above flow, the acoustic impedance at each coordinate point may be calculated after temporarily storing the reflected wave and its Fourier transform value at each measurement point in association with the coordinate value in the memory 33 for all the measurement points. Also in this case, if the image data at all the coordinate points is generated, it is displayed on the display device 36. Alternatively, the acoustic impedance may be converted into another mechanical characteristic and displayed in gradation or color according to the converted value.
上記の方法により、実際に音響窓5に接触する角層51と、皮溝55に当たる部分とを区別し、かつ、内部層からの反射成分を排除して、正確な表面特性の測定が実現する。 By the above method, the horny layer 51 that actually contacts the acoustic window 5 and the portion that abuts the skin groove 55 are distinguished, and the reflection component from the inner layer is eliminated, so that the accurate surface characteristic measurement is realized. ..
図11は、実施形態の表面特性測定装置1を用いて実際に測定した皮膚表面の状態を示す画像である。20歳代から80歳代までの女性70人の頬の皮膚表面を測定している。70人の内訳は、20代(20〜29歳)が19人、40代(40〜49歳)が15人、60代(60〜69歳)が19人、70代及び80代(70〜86歳)が17人である。 FIG. 11 is an image showing the state of the skin surface actually measured using the surface characteristic measuring device 1 of the embodiment. The skin surface of the cheek of 70 women in their 20s to 80s is measured. The breakdown of the 70 persons is 19 persons in their 20s (20 to 29 years old), 15 persons in their 40s (40 to 49 years old), 19 persons in their 60s (60 to 69 years old), 70s and 80s (70 to 70 years old) There are 17 people (86 years old).
測定方法として、今回は、体の動きによる影響を排除してより正確な値を求めるため、プローブ2を垂直に固定して、音響窓5が水平になるように配置した。この音響窓5に対して被測定者の頬を水平に接するように配置し、表面特性測定装置1のプローブ2の先端を頬に押し当て、測定対象部位の皮膚に超音波を照射して測定対象部位からの反射信号を取得して音響インピーダンスを計算した。プローブ2の音響窓5は、厚さ0.5mmのアクリルで形成されている。被測定者の頬に、あらかじめカプラントとして生理食塩水を塗布した。測定は、湿度が45%、温度が25℃の一定の条件下で行った。 As a measurement method, this time, the probe 2 is fixed vertically and the acoustic window 5 is arranged horizontally so as to obtain a more accurate value by eliminating the influence of body movement. The subject's cheek is placed horizontally in contact with the acoustic window 5, the tip of the probe 2 of the surface characteristic measuring device 1 is pressed against the cheek, and ultrasonic waves are applied to the skin of the measurement target site for measurement. The reflected signal from the target site was acquired and the acoustic impedance was calculated. The acoustic window 5 of the probe 2 is made of acryl having a thickness of 0.5 mm. A physiological saline solution was previously applied as couplant to the cheek of the subject. The measurement was performed under constant conditions of humidity of 45% and temperature of 25°C.
図11は、各測定グループで、音響インピーダンスの分布の代表例を選択した結果を示す。画像中の音響インピーダンスが高い部分(白色及び色の薄い部分)が皮膚、音響インピーダンスが低い部分(黒または色の濃い部部)は気泡やカプラントである。測定部位からの反射信号は、あらかじめ取得した参照物質(生理食塩水)の参照反射信号との相互相関がとられ、相互相関関数の最大値を指標に、界面での反射成分を計算して音響インピーダンスが計算されている。算出された音響インピーダンスは、内部反射による干渉成分が除去された正確な測定結果を示している。 FIG. 11 shows the result of selecting a representative example of the acoustic impedance distribution in each measurement group. In the image, a portion with high acoustic impedance (white and light-colored portion) is skin, and a portion with low acoustic impedance (black or dark-colored portion) is air bubbles or couplant. The reflection signal from the measurement site is cross-correlated with the reference reflection signal of the reference substance (saline solution) acquired in advance, and the reflection component at the interface is calculated using the maximum value of the cross-correlation function as an index. Impedance is calculated. The calculated acoustic impedance shows an accurate measurement result in which the interference component due to internal reflection is removed.
年齢が高くなるにつれ、画像中のインピーダンスは白くなっている(高インピーダンス)ことがわかる。図11(A)の20代の皮膚は、全体的にインピーダンス分布が均一である。これは、皮丘が弾力を持って均等に盛り上がり、きめが揃っていることを示す。40代、60代、80代と年齢が進むにつれて、高インピーダンス部分が増える。これは、加齢にともなって角層が厚くなり、きめが粗くなっているためと考えられる。また、40代、60代で局所的に低インピーダンス部分存在するのは、角層の肥厚によるしわ、ひび割れにカプラントが入り込んで音響インピーダンスが低くなっているためと考えられる。このように、音響インピーダンスを用いた皮膚表面の測定結果からは、凹凸の影響や皮膚内部の影響を除く、角層の正確な音響インピーダンス値だけでなく、肌のきめの細かさや、なめらかさについても情報を得ることができる。 It can be seen that the impedance in the image becomes whiter (higher impedance) as the age increases. The impedance distribution of the skin in its twenties in FIG. 11A is uniform throughout. This indicates that the skin mounds are elastic and evenly raised, and the texture is even. High-impedance parts increase as people age, in their 40s, 60s, and 80s. It is considered that this is because the horny layer becomes thicker and the texture becomes rougher with aging. Further, it is considered that the low impedance part locally exists in the 40s and 60s because the acoustic impedance is low because couplant enters the wrinkles and cracks due to the thickening of the stratum corneum. In this way, from the measurement results of the skin surface using acoustic impedance, not only the accurate acoustic impedance value of the stratum corneum, which excludes the influence of unevenness and the influence of the inside of the skin, but also about the fineness and smoothness of the skin Can also get information.
図12は、図11の測定結果に基づく年代別の平均音響インピーダンスを示す。グループ分けした4つのグループのうち、20代(20〜29歳)の平均音響インピーダンスを年齢「20」に示す。40代(40〜49歳)の平均音響インピーダンスを年齢「40」に示す。60代(60〜69歳)の平均音響インピーダンスを年齢「60」に示す。70代及び80代(70〜86歳)の音響インピーダンスを年齢「80」に示す。年齢が高くなるにつれ、音響インピーダンスが高くなる傾向がみられ、加齢にともなう角層の硬化との関連性が推察される。 FIG. 12 shows the average acoustic impedance by age based on the measurement result of FIG. 11. Of the four groups divided into groups, the average acoustic impedance of the twenties (20 to 29 years old) is shown in age “20”. The average acoustic impedance of people in their 40s (40 to 49 years old) is shown in age “40”. The average acoustic impedance in the 60s (60 to 69 years old) is shown in age "60". The acoustic impedance in the 70s and 80s (70 to 86 years old) is shown in age "80". The acoustic impedance tends to increase as the age increases, and it is inferred that this may be related to the hardening of the stratum corneum with aging.
図11のように、あらかじめ各年代別の平均音響インピーダンス分布を取得しておくことで、被測定者の肌年齢を推定することができる。肌年齢は実際の年齢と一致することもあれば、一致しないこともある。測定された肌年齢が実際の年齢よりも高い場合は、そごの程度に応じた措置を推奨することができる。 As shown in FIG. 11, the skin age of the measurement subject can be estimated by acquiring the average acoustic impedance distribution for each age in advance. The skin age may or may not match the actual age. If the measured skin age is higher than the actual age, measures depending on the degree of the chick can be recommended.
このように、実施形態の表面特性測定の構成と手法を用いることで、より正確な表面特性の評価(図7のステップS108)が実現できる。 As described above, by using the surface characteristic measurement configuration and method of the embodiment, more accurate surface characteristic evaluation (step S108 in FIG. 7) can be realized.
上記の方法を表面特性測定プログラムで実現する場合は、メモリ33または記憶装置37にあらかじめ表面特性測定プログラムを記憶し、CPU31で表面特性測定プログラムを読み出して実行する。表面特性測定プログラムは、CPU31に、
(a)測定対象物に照射された超音波の反射信号を取得する手順と、
(b)前記測定対象物からの反射信号と、あらかじめ取得された参照物質からの参照反射信号との相互相関関数の最大値を計算する手順と、
(c)前記相互相関関数の最大値を用いて前記測定対象物の界面での反射成分を計算する手順と、
(d)前記反射成分と前記参照反射信号の比較結果に応じて、前記測定対象物の音響インピーダンスと前記参照物質の音響インピーダンスのいずれか一方を測定値として出力する手順と、
を実行させる。これにより表面特性を高精度に測定することができる。
When the above method is implemented by the surface characteristic measuring program, the surface characteristic measuring program is stored in the memory 33 or the storage device 37 in advance, and the CPU 31 reads and executes the surface characteristic measuring program. The surface characteristic measurement program is executed by the CPU 31.
(A) a procedure for acquiring a reflection signal of the ultrasonic wave applied to the measurement target;
(B) a step of calculating the maximum value of the cross-correlation function between the reflection signal from the measurement object and the reference reflection signal obtained from the reference substance, which is acquired in advance;
(C) A procedure of calculating a reflection component at the interface of the measurement object using the maximum value of the cross-correlation function,
(D) a step of outputting one of the acoustic impedance of the measurement object and the acoustic impedance of the reference substance as a measurement value in accordance with the comparison result of the reflection component and the reference reflection signal,
To run. Thereby, the surface characteristics can be measured with high accuracy.
本発明によれば、検体または試料の表面の硬さ情報を精度良く測定することができるため、皮膚、毛髪、爪、歯片など生体表面の力学特性、有機または無機の表面・表層の物理特性や欠陥の有無等の評価に利用することができる。 According to the present invention, since the hardness information of the surface of the sample or the sample can be accurately measured, the mechanical properties of the surface of the living body such as skin, hair, nails and tooth pieces, the physical properties of the organic or inorganic surface/surface layer. It can be used to evaluate the presence or absence of defects.
1 表面特性測定装置
2 プローブ
3 情報処理装置
5 音響窓
21 超音波センサ回路
31 CPU(プロセッサ)
33 メモリ
34 DSP(信号処理部)
37 記憶装置
1 Surface Characteristic Measuring Device 2 Probe 3 Information Processing Device 5 Acoustic Window 21 Ultrasonic Sensor Circuit 31 CPU (Processor)
33 memory 34 DSP (signal processing unit)
37 storage device
Claims (13)
測定装置にて、前記測定対象物からの反射信号と、あらかじめ取得した参照物質からの参照反射信号との相互相関関数の最大値を計算し、
前記相互相関関数の最大値を用いて界面での反射成分を計算し、
前記反射成分と前記参照反射信号の比較結果に応じて、前記測定対象物の音響インピーダンスと前記参照物質の音響インピーダンスのいずれか一方を測定値として出力する、
ことを特徴とする表面特性測定方法。 Obtain a reflection signal from the measurement object by irradiating the measurement object with ultrasonic waves,
In the measurement device, the maximum value of the cross-correlation function of the reflection signal from the measurement object and the reference reflection signal from the reference material previously acquired,
Calculating the reflection component at the interface using the maximum value of the cross-correlation function,
Depending on the comparison result of the reflection component and the reference reflection signal, one of the acoustic impedance of the measurement object and the acoustic impedance of the reference material is output as a measurement value,
A method for measuring surface characteristics, which comprises:
座標点ごとに前記測定値を出力する
ことを特徴とする請求項1〜4のいずれか1項に記載の表面特性測定方法。 One-dimensionally or two-dimensionally scan the ultrasonic wave relative to the measurement object,
The surface characteristic measuring method according to claim 1, wherein the measured value is output for each coordinate point.
前記測定値に基づいて、前記皮膚の弾性、きめ、毛穴、しわの少なくともひとつを評価することを特徴とする請求項1〜7のいずれか1項に記載の表面特性測定方法。 The measurement object is skin,
The surface property measuring method according to claim 1, wherein at least one of elasticity, texture, pores, and wrinkles of the skin is evaluated based on the measured value.
前記測定値に基づいて、最表層の表面粗さ、弾性、欠陥の少なくともひとつを評価することを特徴とする請求項1〜7のいずれか1項に記載の表面特性測定方法。 The measurement object is an organic or inorganic single-layer or laminated substance,
The surface property measuring method according to claim 1, wherein at least one of the surface roughness, elasticity, and defects of the outermost layer is evaluated based on the measured value.
測定対象物に照射された超音波の反射信号を取得する手順と、
前記測定対象物からの反射信号と、あらかじめ取得された参照物質からの参照反射信号との相互相関関数の最大値を計算する手順と、
前記相互相関関数の最大値を用いて、界面での反射成分を計算する手順と、
前記反射成分と前記参照反射信号の比較結果に応じて、前記測定対象物の音響インピーダンスと前記参照物質の音響インピーダンスのいずれか一方を測定値として出力する手順と、
を実行させる表面特性測定プログラム。 To the processor,
A procedure for acquiring the reflection signal of the ultrasonic wave irradiated to the measurement object,
A procedure for calculating the maximum value of the cross-correlation function of the reflection signal from the measurement object and the reference reflection signal from the previously acquired reference substance,
Calculating the reflection component at the interface using the maximum value of the cross-correlation function;
Depending on the comparison result of the reflection component and the reference reflection signal, a procedure for outputting one of the acoustic impedance of the measurement object and the acoustic impedance of the reference material as a measurement value,
A surface property measurement program that executes.
あらかじめ測定した参照物質からの参照反射信号の強度と、前記参照物質の音響インピーダンスを記憶するメモリと、
前記測定対象物からの反射信号と前記参照反射信号との相互相関関数の最大値に基づいて界面での反射成分を計算し、前記反射成分と前記参照反射信号の比較結果に応じて、前記測定対象物の音響インピーダンスと前記参照物質の音響インピーダンスのいずれか一方を測定値として出力する信号処理部と、
を有することを特徴とする表面特性測定装置。 An ultrasonic wave transmitting/receiving unit that irradiates the measurement object with ultrasonic waves and receives a reflection signal from the measurement object,
Intensity of the reference reflection signal from the reference material measured in advance, and a memory for storing the acoustic impedance of the reference material,
Calculate the reflection component at the interface based on the maximum value of the cross-correlation function of the reflection signal from the measurement object and the reference reflection signal, depending on the comparison result of the reflection component and the reference reflection signal, the measurement A signal processing unit that outputs one of the acoustic impedance of the object and the acoustic impedance of the reference material as a measurement value,
An apparatus for measuring surface characteristics, comprising:
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