JP2012085792A - Pulse wave propagation velocity measuring device - Google Patents

Pulse wave propagation velocity measuring device Download PDF

Info

Publication number
JP2012085792A
JP2012085792A JP2010234570A JP2010234570A JP2012085792A JP 2012085792 A JP2012085792 A JP 2012085792A JP 2010234570 A JP2010234570 A JP 2010234570A JP 2010234570 A JP2010234570 A JP 2010234570A JP 2012085792 A JP2012085792 A JP 2012085792A
Authority
JP
Japan
Prior art keywords
wave
pulse wave
volume
reference time
ejection
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
JP2010234570A
Other languages
Japanese (ja)
Other versions
JP5690550B2 (en
Inventor
Atsushi Hori
淳史 堀
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Sharp Corp
Original Assignee
Sharp Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Sharp Corp filed Critical Sharp Corp
Priority to JP2010234570A priority Critical patent/JP5690550B2/en
Publication of JP2012085792A publication Critical patent/JP2012085792A/en
Application granted granted Critical
Publication of JP5690550B2 publication Critical patent/JP5690550B2/en
Expired - Fee Related legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Landscapes

  • Measuring Pulse, Heart Rate, Blood Pressure Or Blood Flow (AREA)

Abstract

PROBLEM TO BE SOLVED: To provide a pulse wave propagation velocity measuring device capable of accurately obtaining the propagation velocity of an ejection wave of pulse waves in consideration of the difference between the velocity of the ejection wave of pulse waves and the velocity of reflected waves.SOLUTION: In this pulse wave propagation velocity measuring device 100, a reference time detecting section 121 detects the reference time T1 of an ejection wave component S1 and the reference time T2 of a reflected wave component S2, and a pulse wave amplitude detecting section 122 detects the amplitude W1 of the ejection wave component S1 corresponding to the reference time T1 and the amplitude W3 of the reflected wave component S2 corresponding to the reference time T2. A pulse wave propagation velocity detecting section 130 obtains the propagation velocity PWVf of the ejection wave based on the reference times T1, T2 and the ratio of the amplitude W1 of the ejection wave component S1 corresponding to the reference time T1, to the amplitude W3 of the reflected wave component S2 corresponding to the reference time T2.

Description

この発明は、生体の脈波を測定することで、脈波の伝搬する速度を算出する脈波伝播速度測定装置に関する。   The present invention relates to a pulse wave velocity measuring apparatus that calculates a velocity at which a pulse wave propagates by measuring a pulse wave of a living body.

従来、脈波は生体の循環器系の状態を把握する上で様々な重要な情報を有していることが知られている。特に、生体の２箇所を脈波が伝播する速度および時間は動脈硬化状態などが把握できる可能性が指摘され、医療現場でも注目されている生体指標であり、それぞれ脈波伝播速度(ＰＷＶ:Ｐulse Ｗave Ｖelocity)、脈波伝播時間(ＰＴＴ:Ｐulse Ｔransit Ｔime)などと呼ばれている。   Conventionally, it is known that a pulse wave has various important information for grasping the state of a living body's circulatory system. In particular, the speed and time at which a pulse wave propagates through two locations of a living body is a biological index that has been pointed out to be able to grasp the arteriosclerosis state and the like, and is also attracting attention in the medical field, and the pulse wave propagation speed (PWV: Pulse) Wave Velocity), pulse wave propagation time (PTT: Pulse Transit Time), etc.

脈波伝播速度には、測定箇所に応じて複数の測定手法が提案されており、例えば、頚動脈と大腿動脈間の脈波伝播速度は、ｃｆＰＷＶ(carotid-ｆemoral ＰＷＶ)と呼ばれ、脈波伝播速度(ＰＷＶ)におけるゴールドスタンダードとして利用されている。   A plurality of measurement methods have been proposed for the pulse wave velocity according to the measurement location. For example, the pulse wave velocity between the carotid artery and the femoral artery is called cfPWV (carotid-femoral PWV). Used as a gold standard in speed (PWV).

一般的に、上記脈波伝播速度(ＰＷＶ)を求めるには、２箇所の脈波測定点が必要である。   In general, two pulse wave measurement points are required to obtain the pulse wave velocity (PWV).

しかしながら、生体上のいずれの部位で測定された脈波であっても、心臓からの駆出波と生体内の様々な箇所から反射された反射波との合成波であることが知られている。そして、この駆出波と反射波とを分離することで、脈波の測定部位が１箇所であっても、脈波伝播速度あるいは脈波伝播時間を求めることができる可能性がある。   However, it is known that the pulse wave measured at any part on the living body is a composite wave of the ejection wave from the heart and the reflected wave reflected from various places in the living body. . Then, by separating the ejection wave and the reflected wave, there is a possibility that the pulse wave propagation speed or the pulse wave propagation time can be obtained even if there is only one pulse wave measurement site.

そこで、非特許文献１(Ｔakazawa Ｋ et al.”Ｕnderestimation of vasodilator effects of nitroglycerin by upper limb blood pressure”， Ｈypertension １９９５; ２６:５２０−３)では、駆出波と反射波を分離するための技術が開示されている。また、特許文献１(特許３４９５３４８号公報)や特許文献２(特開２００７−００７０７５号公報)では、駆出波と反射波を分離することによって、脈波の測定部位が１箇所であっても、脈波伝播速度あるいは脈波伝播時間を求めるための技術が開示されている。   Therefore, in Non-Patent Document 1 (Takazawa K et al. “Underestimation of vasodilator effects of nitroglycerin by upper limb blood pressure”, Hypertension 1995; 26: 520-3), there is a technique for separating ejection waves and reflected waves. It is disclosed. Further, in Patent Document 1 (Japanese Patent No. 3495348) and Patent Document 2 (Japanese Patent Laid-Open No. 2007-007075), even if there is only one pulse wave measurement site by separating the ejection wave and the reflected wave, A technique for obtaining a pulse wave propagation speed or pulse wave propagation time is disclosed.

一般的に、脈波は生体内の各所において反射が発生している。この脈波の反射は、血管のインピーダンス不整合が主因であり、例えば、血管の分岐や血管の弾性力の変化などが在る箇所において反射が発生する。   In general, the pulse wave is reflected at various points in the living body. The reflection of the pulse wave is mainly due to the impedance mismatch of the blood vessel. For example, the reflection occurs at a location where there is a branch of the blood vessel or a change in the elastic force of the blood vessel.

ここで、特許文献１でも述べられているように、駆出波と反射波を分離する際には、主たる反射点が腸骨動脈あるいは腹部大動脈周辺にあると仮定すると、生体各部で測定された脈波に対して、駆出波と反射波の分離がうまく行く。   Here, as described in Patent Document 1, when separating the ejection wave and the reflected wave, it was measured at each part of the living body assuming that the main reflection point is around the iliac artery or the abdominal aorta. Separation of ejected wave and reflected wave is good for pulse wave.

また、脈波伝播速度あるいは脈波伝播時間は血圧と相関があり、特許文献２には、１箇所の測定部位から得られた脈波から脈波伝播速度あるいは脈波伝播時間を算出し、血圧を同定するための技術が開示されている。また、非特許文献２(ＭcＣombie，Ｄevin “Ｄevelopment of a wearable blood pressure monitor using adaptive calibration of peripheral pulse transit time measurements”，Ｐh.Ｄ. Ｔhesis， Ｍassachusetts Ｉnstitute of Ｔechnology，Ｄept. of Ｍechanical Ｅngineering，２００８.)には、２箇所の測定部位から得られた脈波から脈波伝播速度あるいは脈波伝播時間を算出し、血圧を同定するための技術が開示されている。   Further, the pulse wave velocity or pulse wave propagation time has a correlation with blood pressure. In Patent Document 2, the pulse wave velocity or pulse wave propagation time is calculated from the pulse wave obtained from one measurement site, and the blood pressure is calculated. Techniques for identifying are disclosed. In Non-Patent Document 2 (McCombie, Devin “Development of a wearable blood pressure monitor using adaptive calibration of peripheral pulse transit time measurements”, Ph.D. Thesis, Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2008.) Discloses a technique for calculating a pulse wave velocity or pulse wave propagation time from pulse waves obtained from two measurement sites and identifying blood pressure.

ところで、上述の特許文献１および２のいずれにおいても、１箇所の測定部位の脈波から脈波伝播速度あるいは脈波伝播時間を求めることができるとされているが、その前提として駆出波と反射波それぞれの脈波伝播速度が同じであることを前提にしている。この前提にしたがって、(1)１つの脈波を駆出波と反射波に分離して両者の基準時間差を求め、(2)脈波の駆出波と反射波のそれぞれが伝播する距離の差を求めている。この基準時間差と距離の差とから、脈波伝播速度あるいは脈波伝播時間を求めている。   In both Patent Documents 1 and 2, it is said that the pulse wave velocity or pulse wave propagation time can be obtained from the pulse wave at one measurement site. It is assumed that the pulse wave velocity of each reflected wave is the same. In accordance with this premise, (1) one pulse wave is separated into ejected wave and reflected wave to obtain the reference time difference between them, and (2) the difference in the distance that each of the ejected wave and reflected wave propagates. Seeking. From this reference time difference and distance difference, the pulse wave propagation speed or pulse wave propagation time is obtained.

しかしながら、実際には、駆出波の脈波伝播速度と反射波の脈波伝播速度は一致しない。何故ならば、駆出波の振幅と反射波の振幅は異なっているからである。前述の特許文献２に記載されている通り、脈波伝播速度は血圧と相関があるが、血圧は脈波の振幅に関係している。つまり、脈波伝播速度は脈波の振幅に関係しているのである。   However, actually, the pulse wave propagation speed of the ejection wave and the pulse wave propagation speed of the reflected wave do not match. This is because the ejection wave and the reflected wave have different amplitudes. As described in Patent Document 2 described above, the pulse wave velocity is correlated with the blood pressure, but the blood pressure is related to the amplitude of the pulse wave. In other words, the pulse wave propagation speed is related to the amplitude of the pulse wave.

上述の通り、反射波は反射点を腹部大動脈分岐周辺と想定することで脈波の波形形状をうまく説明できる。脈波の反射が起こる理由は、大動脈と腹部大動脈分岐におけるインピーダンス不整合があるためである。反射波は進行波が反射した波であるので、進行波の大きさと反射波の大きさは違う。したがって、駆出波と反射波の脈波伝播速度は異なるのである。   As described above, the waveform of the pulse wave can be well explained by assuming that the reflected wave is around the abdominal aortic branch. The reason for the reflection of the pulse wave is that there is an impedance mismatch between the aorta and the abdominal aortic branch. Since the reflected wave is a wave reflected from the traveling wave, the magnitude of the traveling wave is different from the magnitude of the reflected wave. Therefore, the pulse wave propagation speeds of the ejection wave and the reflected wave are different.

ところで、Ｂramwell-Ｈillの式によると脈波伝搬速度ＰＷＶは、次式(１０１)のように、血管の体積弾性率と血液の密度で求められることが知られている(非特許文献３(Nichols WW and O’Rourke MF , "McDonald’s blood flow in arteries. Theoretical, experimental and clinical principles." ４th edition, Arnold, London, １９９８.)参照)。
ＰＷＶ＝(ｋ/ρ)１／２＝{(Ｖ×ｄＰ)／(ρ×ｄＶ)}１／２ … (１０１) By the way, according to the Bramwell-Hill equation, it is known that the pulse wave propagation velocity PWV is obtained from the volumetric modulus of blood vessels and the density of blood as in the following equation (101) (Non-Patent Document 3 (Nichols WW and O'Rourke MF, "McDonald's blood flow in arteries. Theoretical, experimental and clinical principles." 4th edition, Arnold, London, 1998.)).
PWV = (k / ρ) 1/2 = {(V × dP) / (ρ × dV)} 1/2 (101)

上式(１０１)において、ｋは血管の容積弾性率、ρは血液の密度、Ｖは血管の容積、ｄＰは拍動により血管に加わる圧力変化、ｄＶはｄＰの圧力変化に対する血管容積の変化量を表している。   In the above equation (101), k is the volumetric elastic modulus of the blood vessel, ρ is the density of blood, V is the volume of the blood vessel, dP is the change in pressure applied to the blood vessel by pulsation, and dV is the amount of change in the blood vessel volume with respect to the pressure change of dP Represents.

よって、駆出波および反射波それぞれにおける血管容積の変化量を同定することができれば、駆出波と反射波の速度が異なることを考慮することが可能となり、より精度良く脈波伝搬速度を算出することが可能となる。   Therefore, if the amount of change in blood vessel volume in each ejection wave and reflected wave can be identified, it is possible to take into account the difference in velocity between the ejection wave and the reflected wave, and the pulse wave propagation speed can be calculated more accurately. It becomes possible to do.

特開２００３−１０１３９号公報JP 2003-10139 A 特開２００７−７０７５号公報JP 2007-7075 A

Takazawa K et al., ”Underestimation of vasodilator effects of nitroglycerin by upper limb blood pressure”, Hypertension １９９５; ２６:５２０-３Takazawa K et al., “Underestimation of vasodilator effects of nitroglycerin by upper limb blood pressure”, Hypertension 1995; 26: 520-3. McCombie, Devin, “Development of a wearable blood pressure monitor using adaptive calibration of peripheral pulse transit time measurements”,Ph.D. Thesis, Massachusetts Institute of Technology, Dept. of Mechanical Engineering,２００８.McCombie, Devin, “Development of a wearable blood pressure monitor using adaptive calibration of peripheral pulse transit time measurements”, Ph.D. Thesis, Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2008. Nichols WW and O’Rourke MF , "McDonald’s blood flow in arteries. Theoretical, experimental and clinical principles." ４th edition, Arnold, London, １９９８.Nichols WW and O’Rourke MF, “McDonald ’s blood flow in arteries. Theoretical, experimental and clinical principles.” 4th edition, Arnold, London, 1998. Segers P, Rietzschel ER, et al. , “Noninvasive (input) impedance, pulse wave velocity, and wave reflection in healthy middle−aged men and women.”, Hypertension. ２００７;４９:１２４８-５５.Segers P, Rietzschel ER, et al., “Noninvasive (input) impedance, pulse wave velocity, and wave reflection in healthy middle-aged men and women.”, Hypertension. 2007; 49: 1248-55.

そこで、この発明の課題は、脈波の駆出波の速度と反射波の速度とが異なることを考慮に入れて、脈波の駆出波の伝播速度を精度良く求めることが可能な脈波伝播速度測定装置を提供することにある。   Accordingly, an object of the present invention is to take into account that the speed of the pulse wave ejection wave is different from the speed of the reflected wave, and to determine the propagation speed of the pulse wave ejection wave with high accuracy. It is to provide a propagation velocity measuring device.

上記課題を解決するため、この発明の脈波伝播速度測定装置は、生体の或る一部位における容積脈波を検出する容積脈波検出部と、
上記容積脈波検出部で検出した上記一部位における容積脈波に含まれる駆出波成分を特定するための基準時間と上記容積脈波に含まれる反射波成分を特定するための基準時間とを検出する基準時間検出部と、
上記容積脈波検出部で検出した容積脈波に基づいて、上記基準時間検出部で検出した上記駆出波成分の基準時間に対応する上記駆出波成分による血管の容積の変化量と、上記基準時間検出部で検出した上記反射波成分の基準時間に対応する上記反射波成分による血管の容積の変化量を検出する容積変化量検出部と、
上記基準時間検出部で検出した上記駆出波成分の基準時間および上記反射波成分の基準時間と、上記容積変化量検出部で検出した上記駆出波成分による血管の容積の変化量および上記反射波成分による血管の容積の変化量とに基づいて、上記容積脈波の駆出波の伝播速度を求める伝播速度検出部とを備えることを特徴としている。 In order to solve the above problems, a pulse wave velocity measuring device of the present invention includes a volume pulse wave detection unit that detects a volume pulse wave in a certain part of a living body,
A reference time for specifying the ejection wave component included in the volume pulse wave at the partial position detected by the volume pulse wave detection unit and a reference time for specifying the reflected wave component included in the volume pulse wave A reference time detection unit to detect;
Based on the volume pulse wave detected by the volume pulse wave detection unit, the change amount of the volume of the blood vessel due to the ejection wave component corresponding to the reference time of the ejection wave component detected by the reference time detection unit, and A volume change amount detecting unit for detecting a change amount of a blood vessel volume due to the reflected wave component corresponding to a reference time of the reflected wave component detected by a reference time detecting unit;
The reference time of the ejection wave component and the reference time of the reflected wave component detected by the reference time detection unit, the change amount of the blood vessel volume by the ejection wave component detected by the volume change amount detection unit, and the reflection And a propagation speed detector that obtains the propagation speed of the ejection pulse of the volume pulse wave based on the change in the volume of the blood vessel due to the wave component.

この発明の脈波伝播速度測定装置によれば、上記容積脈波検出部で生体の或る一部位における容積脈波を検出し、上記基準時間検出部で上記検出した容積脈波の駆出波成分の基準時間と反射波成分の基準時間とを検出し、さらに、上記容積変化量検出部で上記駆出波成分による血管の容積の変化量と上記反射波成分による血管の容積の変化量とを求める。そして、上記伝播速度検出部は、上記容積脈波の駆出波成分の基準時間と反射波成分の基準時間および上記駆出波成分による血管の容積の変化量と上記反射波成分による血管の容積の変化量とに基づいて、上記容積脈波の駆出波の伝播速度を求める。これにより、容積脈波の駆出波の脈波伝播速度と反射波の脈波伝播速度との違いを考慮した上でのより精度の高い駆出波の伝播速度を求めることができる。   According to the pulse wave velocity measuring device of the present invention, the volume pulse wave detection unit detects a volume pulse wave in a certain part of the living body, and the reference time detection unit detects the volume pulse wave ejected. The reference time of the component and the reference time of the reflected wave component are detected, and further, the change amount of the blood vessel volume due to the ejection wave component and the change amount of the blood vessel volume due to the reflected wave component are detected by the volume change amount detection unit. Ask for. The propagation velocity detection unit includes a reference time of the ejection wave component of the volume pulse wave, a reference time of the reflected wave component, a change in the volume of the blood vessel due to the ejection wave component, and a volume of the blood vessel due to the reflected wave component. The propagation speed of the ejection pulse of the volume pulse wave is obtained based on the change amount of the volume pulse wave. Accordingly, it is possible to obtain a more accurate ejection wave propagation speed in consideration of the difference between the pulse wave propagation speed of the volume pulse wave and the pulse wave propagation speed of the reflected wave.

また、一実施形態の脈波伝播速度測定装置では、上記伝播速度検出部は、
上記容積変化量検出部で検出した上記駆出波成分による血管の容積の変化量と上記反射波成分による血管の容積の変化量との比率を求め、この比率と上記基準時間検出部で検出した上記駆出波成分の基準時間および上記反射波成分の基準時間に基づいて、上記容積脈波の駆出波の伝播速度を求める。 Moreover, in the pulse wave velocity measuring apparatus of one embodiment, the propagation velocity detector is
The ratio of the change amount of the blood vessel volume due to the ejection wave component detected by the volume change amount detection unit and the change amount of the blood vessel volume due to the reflected wave component is obtained, and this ratio and the reference time detection unit detect Based on the reference time of the ejection wave component and the reference time of the reflected wave component, the propagation speed of the ejection wave of the volume pulse wave is obtained.

この実施形態によれば、上記伝播速度検出部は、上記容積変化量検出部で求めた上記駆出波成分による血管の容積の変化量と上記反射波成分による血管の容積の変化量との比率と上記基準時間検出部で検出した上記駆出波成分の基準時間および上記反射波成分の基準時間に基づいて、上記容積脈波の駆出波の伝播速度を求める。これにより、容積脈波の駆出波の脈波伝播速度と反射波の脈波伝播速度との違いを考慮した上でのより精度の高い駆出波の伝播速度を求めることができる。   According to this embodiment, the propagation velocity detection unit is a ratio of a change amount of the blood vessel volume due to the ejection wave component obtained by the volume change amount detection unit and a change amount of the blood vessel volume due to the reflected wave component. The propagation speed of the ejection pulse of the volume pulse wave is obtained based on the reference time of the ejection wave component detected by the reference time detection unit and the reference time of the reflected wave component. Accordingly, it is possible to obtain a more accurate ejection wave propagation speed in consideration of the difference between the pulse wave propagation speed of the volume pulse wave and the pulse wave propagation speed of the reflected wave.

また、一実施形態の脈波伝播速度測定装置では、上記容積脈波検出部が検出する容積脈波は、生体の或る一部位における光電容積脈波である。   Moreover, in the pulse wave velocity measuring device of one embodiment, the volume pulse wave detected by the volume pulse wave detection unit is a photoelectric volume pulse wave in a certain part of the living body.

この実施形態によれば、上記容積脈波検出部が検出する光電容積脈波に基づき、駆出波の伝播速度を高い精度で求めることができる。   According to this embodiment, the propagation speed of the ejection wave can be obtained with high accuracy based on the photoelectric volume pulse wave detected by the volume pulse wave detector.

また、一実施形態の脈波伝播速度測定装置では、上記伝播速度検出部は、
上記容積変化量検出部で検出した上記駆出波成分による血管の容積の変化量と上記反射波成分による血管の容積の変化量との比率を求め、この比率と上記基準時間検出部で検出した上記駆出波成分の基準時間および上記反射波成分の基準時間に基づいて、上記容積脈波の駆出波の伝播速度を求める。 Moreover, in the pulse wave velocity measuring apparatus of one embodiment, the propagation velocity detector is
The ratio of the change amount of the blood vessel volume due to the ejection wave component detected by the volume change amount detection unit and the change amount of the blood vessel volume due to the reflected wave component is obtained, and this ratio and the reference time detection unit detect Based on the reference time of the ejection wave component and the reference time of the reflected wave component, the propagation speed of the ejection wave of the volume pulse wave is obtained.

この実施形態によれば、上記駆出波成分による血管の容積の変化量と上記反射波成分による血管の容積の変化量との比率と、上記駆出波成分の基準時間および上記反射波成分の基準時間に基づいて、上記容積脈波の駆出波の伝播速度を高精度で求めることができる。   According to this embodiment, the ratio between the change amount of the blood vessel volume due to the ejection wave component and the change amount of the blood vessel volume due to the reflection wave component, the reference time of the ejection wave component, and the reflection wave component Based on the reference time, the propagation speed of the ejection pulse of the volume pulse wave can be obtained with high accuracy.

また、一実施形態の脈波伝播速度測定装置では、上記伝播速度検出部は、
上記容積変化量検出部で検出した上記光電容積脈波の極小点で値と上記駆出波成分の基準時間での上記光電容積脈波の値と上記反射波成分の基準時間での上記光電容積脈波の値とに基づいて、上記駆出波成分による血管の容積の変化量と上記反射波成分による血管の容積の変化量との比率を求め、この比率と上記基準時間検出部で検出した上記駆出波成分の基準時間および上記反射波成分の基準時間に基づいて、上記容積脈波の駆出波の伝播速度を求める。 Moreover, in the pulse wave velocity measuring apparatus of one embodiment, the propagation velocity detector is
The value of the photoelectric volume pulse wave detected at the minimum amount of the photoelectric volume pulse wave, the value of the photoelectric volume pulse wave at the reference time of the ejection wave component, and the photoelectric volume at the reference time of the reflected wave component Based on the value of the pulse wave, a ratio between the change amount of the blood vessel volume due to the ejection wave component and the change amount of the blood vessel volume due to the reflected wave component is obtained, and this ratio and the reference time detection unit detect Based on the reference time of the ejection wave component and the reference time of the reflected wave component, the propagation speed of the ejection wave of the volume pulse wave is obtained.

この実施形態によれば、上記伝播速度検出部は、上記光電容積脈波の極小点で値と上記光電容積脈波の上記駆出波成分の基準時間での値と上記光電容積脈波の上記反射波成分の基準時間での値とに基づいて、上記駆出波成分による血管の容積の変化量と上記反射波成分による血管の容積の変化量との比率をより正確に求めることができる。よって、上記伝播速度検出部は、上記比率と上記駆出波成分の基準時間および上記反射波成分の基準時間に基づいて、上記容積脈波の駆出波の伝播速度をより正確に求めることができる。   According to this embodiment, the propagation velocity detection unit includes a value at a minimum point of the photoelectric volume pulse wave, a value at a reference time of the ejection wave component of the photoelectric volume pulse wave, and the value of the photoelectric volume pulse wave. Based on the value of the reflected wave component at the reference time, the ratio between the change amount of the blood vessel volume due to the ejection wave component and the change amount of the blood vessel volume due to the reflected wave component can be obtained more accurately. Therefore, the propagation velocity detection unit can more accurately determine the propagation velocity of the ejection pulse of the volume pulse wave based on the ratio, the reference time of the ejection wave component, and the reference time of the reflected wave component. it can.

この発明の脈波伝播速度測定装置発によれば、伝播速度検出部は、容積脈波の駆出波成分の基準時間と反射波成分の基準時間および上記駆出波成分による血管の容積の変化量と上記反射波成分による血管の容積の変化量とに基づいて、上記容積脈波の駆出波の伝播速度を求めるので、容積脈波の駆出波の脈波伝播速度と反射波の脈波伝播速度との違いを考慮した上でのより精度の高い駆出波の伝播速度を求めることができる。   According to the pulse wave velocity measuring device of the present invention, the propagation velocity detector includes a reference time of the ejection wave component of the volume pulse wave, a reference time of the reflected wave component, and a change in the volume of the blood vessel due to the ejection wave component. The propagation velocity of the ejection pulse of the volume pulse wave is obtained on the basis of the amount and the amount of change in the volume of the blood vessel due to the reflected wave component, so the pulse wave propagation velocity of the ejection pulse of the volume pulse wave and the pulse wave of the reflected wave are obtained. The propagation speed of the ejection wave with higher accuracy can be obtained in consideration of the difference from the wave propagation speed.

本発明の実施形態としての脈波伝播速度測定装置のブロック図である。It is a block diagram of a pulse wave velocity measuring device as an embodiment of the present invention. 上記実施形態の脈波検出部で検出した容積脈波の波形を(Ａ)欄に示し、上記容積脈波の加速度波形を(Ｂ)欄に示す波形図である。FIG. 6 is a waveform diagram showing the waveform of a volume pulse wave detected by the pulse wave detection unit of the embodiment in the (A) column and the acceleration waveform of the volume pulse wave in the (B) column. 上記脈波検出部で検出した脈波の３回微分波形を(Ａ)欄に示し、上記脈波の４回微分波形を(Ｂ)欄に示す波形図である。It is a wave form diagram which shows the 3rd derivative waveform of the pulse wave detected by the above-mentioned pulse wave detection part in the (A) column, and shows the 4th derivative waveform of the above-mentioned pulse wave in the (B) column. 上記脈波の波形および上記脈波の基準点Ｑ１,Ｑ２での脈波の振幅Ｗ１,Ｗ２を示す波形図である。It is a waveform diagram showing the pulse wave amplitude and pulse wave amplitudes W1 and W2 at the reference points Q1 and Q2 of the pulse wave. 上記脈波の波形および上記脈波の駆出波成分Ｓ１と反射波成分Ｓ２を示す波形図である。It is a wave form diagram which shows the waveform of the said pulse wave, and the ejection wave component S1 and the reflected wave component S2 of the said pulse wave. 上記脈波の駆出波が伝播する距離と上記脈波の反射波が伝播する距離との距離差を説明する模式図である。It is a schematic diagram explaining the distance difference of the distance which the ejection wave of the said pulse wave propagates, and the distance which the reflected wave of the said pulse wave propagates. 上記脈波の駆出波と反射波の速度差を説明する模式図である。It is a schematic diagram explaining the speed difference of the ejection wave and reflected wave of the said pulse wave. ランベルト・ベール(Ｌambert-ｂeer)の法則を説明する模式図である。It is a schematic diagram explaining the Lambert-Beer's law. 光電容積脈波形の極小点,駆出点,反射点を示す波形図である。It is a wave form diagram which shows the minimum point, ejection point, and reflection point of a photoelectric volume pulse waveform. 上記光電容積脈波形の極小点における血管径光の透過光量Ｉｍをモデル化した模式図である。It is the schematic diagram which modeled the transmitted light quantity Im of the blood vessel diameter light in the minimum point of the said photoelectric volume pulse waveform. 上記光電容積脈波形の駆出波成分の極大点における血管径と光の透過光量Ｉｆをモデル化した模式図である。It is the model which modeled the blood vessel diameter and the transmitted light amount If of the light in the maximum point of the ejection wave component of the said photoelectric volume pulse waveform. 上記光電容積脈波形の反射波成分の極大点における血管径と光の透過光量Ｉｒをモデル化した模式図である。It is the model which modeled the blood vessel diameter and the transmitted light amount Ir of the light in the maximum point of the reflected wave component of the said photoelectric volume pulse waveform.

以下、この発明を図示の実施の形態により詳細に説明する。   Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

図１は、本発明の実施形態としての脈波伝播速度測定装置１００のブロック図である。   FIG. 1 is a block diagram of a pulse wave velocity measuring apparatus 100 as an embodiment of the present invention.

この脈波伝播速度測定装置１００の主な構成要素は、容積脈波検出部１１０と、駆出波・反射波情報抽出部１２０と、脈波伝播速度検出部１３０である。   The main components of the pulse wave velocity measuring apparatus 100 are a volume pulse wave detector 110, an ejection wave / reflected wave information extractor 120, and a pulse wave velocity detector 130.

上記容積脈波検出部１１０は、生体の所定部位における容積脈波を検出する。この容積脈波検出部１１０による容積脈波の検出方法には、種々様々な方法がある。例えば、カフを生体組織に巻いて生体組織内の血液容積変化を測定するカフ容積脈波法や、発光素子から出力される赤外光が血管内の血液量に応じて反射あるいは吸収される度合いを受光素子で測定する光電容積脈波法などがある。また、上記容積脈波検出部１１０によって脈波を測定する生体部位は、特に大きな制限事項があるわけではないが、でき得るなら、非侵襲,非拘束であることが望ましく、例えば、指尖,手首,上腕,耳朶などが好ましい。   The plethysmogram detection unit 110 detects a plethysmogram at a predetermined part of the living body. There are various methods for detecting the volume pulse wave by the volume pulse wave detection unit 110. For example, the cuff volume pulse wave method in which a cuff is wrapped around a living tissue to measure a change in blood volume in the living tissue, or the degree to which infrared light output from the light emitting element is reflected or absorbed depending on the blood volume in the blood vessel There is a photoelectric volume pulse wave method or the like that measures the above with a light receiving element. In addition, the body part for measuring the pulse wave by the volume pulse wave detection unit 110 is not particularly limited, but is preferably non-invasive and non-constrained if possible. Wrist, upper arm, earlobe and the like are preferable.

上記駆出波・反射波特徴情報抽出部１２０は、基準時間検出部１２１と容積変化量検出部としての脈波振幅検出部１２２とからなる。   The ejection wave / reflected wave feature information extraction unit 120 includes a reference time detection unit 121 and a pulse wave amplitude detection unit 122 as a volume change amount detection unit.

上記基準時間検出部１２１は、容積脈波検出部１１０で検出した上記脈波に含まれる駆出波成分を特定するための基準時間と上記脈波に含まれる反射波成分を特定するための基準時間とを検出する。   The reference time detector 121 includes a reference time for specifying the ejection wave component included in the pulse wave detected by the volume pulse wave detector 110 and a reference for specifying the reflected wave component included in the pulse wave. Detect time and.

この基準時間検出部１２１が上記基準時間を求める過程の一例を以下に説明する。まず、図２の(Ａ)欄に、上記容積脈波検出部１１０で検出した脈波の波形の一例を示す。図２の(Ａ)欄における縦軸は脈波の振幅(ｍｍＨｇ)に対応する測定電圧値(Ｖ)である。   An example of a process in which the reference time detection unit 121 obtains the reference time will be described below. First, an example of the waveform of the pulse wave detected by the volume pulse wave detection unit 110 is shown in the column (A) of FIG. The vertical axis in the column (A) of FIG. 2 is the measured voltage value (V) corresponding to the amplitude (mmHg) of the pulse wave.

上記基準時間検出部１２１は、例えば、上記脈波が、Ｍｕｒｇｏらによる血圧波形分類のＴｙｐｅＣの場合は、図２Ａの(Ａ)欄に示される脈波の波形における収縮期の極大点Ｑ１の時間Ｔ１を駆出波成分の基準時間Ｔ１として検出する。図２Ａの(Ｂ)欄には、上記脈波の加速度波を示し、図２Ｂの(Ａ)欄には、上記脈波の３回微分波を示している。そして、上記基準時間検出部１２１は、例えば、上記脈波が、Ｍurgoらによる血圧波形分類のＴｙｐｅＣの場合は、図２Ｂの(Ｂ)欄に示される脈波の４次微分波の下向き第３ゼロクロスポイントＱ２を反射波成分の基準時間Ｔ２として検出する。なお、この第３ゼロクロスポイントＱ２は、図２Ａの(Ａ)欄に示す脈波が極小値になった以降に、図２Ｂの(Ｂ)欄に示す４回微分波形が３回目に下向きにゼロクロスするポイントを意味する。   For example, in the case where the pulse wave is Type C of blood pressure waveform classification by Murgo et al., The reference time detection unit 121 sets the time of the systolic maximum point Q1 in the pulse wave waveform shown in the column (A) of FIG. T1 is detected as the reference time T1 of the ejection wave component. The (B) column of FIG. 2A shows the acceleration wave of the pulse wave, and the (A) column of FIG. 2B shows the triple differential wave of the pulse wave. For example, when the pulse wave is Type C of blood pressure waveform classification by Murgo et al., The reference time detection unit 121 has a third downward wave of the fourth-order differential wave of the pulse wave shown in the (B) column of FIG. 2B. The zero cross point Q2 is detected as the reference time T2 of the reflected wave component. The third zero cross point Q2 is the zero crossing of the fourth differential waveform shown in the (B) column of FIG. 2B downward for the third time after the pulse wave shown in the (A) column of FIG. 2A reaches the minimum value. It means the point to do.

なお、上述の説明では、上記検出した脈波が上記血圧波形分類のＴｙｐｅＣである場合について説明したが、上記検出した脈波が上記血圧波形分類のＴｙｐｅＣ以外の波形形状である場合には、より好適に脈波の駆出波成分の基準時間と反射波成分の基準時間を特定できる手法があればそれを採用してもよい。例えば、脈波は、大きな血圧変動がなければ、基本的にそれほど大きな波形変化を示すわけではないので、測定した複数の脈波を重ね合わせる(加算平均)ことで、脈波検出精度の改善を図ることが可能になる。   In the above description, the case where the detected pulse wave is Type C of the blood pressure waveform classification has been described. However, when the detected pulse wave has a waveform shape other than Type C of the blood pressure waveform classification, If there is a method that can suitably specify the reference time of the ejection wave component of the pulse wave and the reference time of the reflected wave component, it may be adopted. For example, if the pulse wave does not show a large blood pressure fluctuation, it basically does not show a very large waveform change, so by superimposing a plurality of measured pulse waves (addition averaging), the pulse wave detection accuracy can be improved. It becomes possible to plan.

また、脈波は、ノイズレベル、年齢,性別,疾病の有無,体調などに応じて、様々な波形形状を示すことから、より好適に脈波の駆出波成分の基準時間と反射波成分の基準時間を特定できる手法があればそれを採用してもよい。例えば、検出した脈波を、その時点の被測定者の状態と合わせて履歴として残すことで、脈波の駆出波成分の基準時間と反射波成分の基準時間を特定する精度の改善を図れる。   In addition, since the pulse wave shows various waveform shapes depending on the noise level, age, sex, presence / absence of disease, physical condition, etc., the reference time of the ejection wave component of the pulse wave and the reflected wave component are more preferably If there is a method that can specify the reference time, it may be adopted. For example, it is possible to improve the accuracy of specifying the reference time of the ejection wave component of the pulse wave and the reference time of the reflected wave component by leaving the detected pulse wave as a history together with the state of the measurement subject at that time. .

また、上記駆出波・反射波情報抽出部１２０は、容積変化量検出部としての脈波振幅検出部１２２を有する。この脈波振幅検出部１２２は、図３の脈波波形図に例示するように、上記基準時間検出部１２１で検出した上記駆出波成分の基準時間Ｔ１に対応する上記脈波Ｓの振幅Ｗ１を検出すると共に上記基準時間検出部２で検出した上記反射波成分の基準時間Ｔ２に対応する上記脈波Ｓの振幅Ｗ２を検出する。なお、容積脈波において脈波振幅情報としての上記脈波Ｓの振幅Ｗ１,Ｗ２は、容積変化量の情報を表している。   The ejection wave / reflected wave information extraction unit 120 includes a pulse wave amplitude detection unit 122 serving as a volume change amount detection unit. As illustrated in the pulse waveform diagram of FIG. 3, the pulse wave amplitude detection unit 122 has an amplitude W1 of the pulse wave S corresponding to the reference time T1 of the ejection wave component detected by the reference time detection unit 121. And the amplitude W2 of the pulse wave S corresponding to the reference time T2 of the reflected wave component detected by the reference time detection unit 2 is detected. In the volume pulse wave, the amplitudes W1 and W2 of the pulse wave S as the pulse wave amplitude information represent information on the volume change amount.

さらに、上記駆出波・反射波情報抽出部１２０は、駆出波成分除去部１２３を有する。この駆出波成分除去部１２３は、図４に示すように、上記反射波成分Ｓ２の基準時間Ｔ２に対応する上記脈波Ｓの振幅Ｗ２から上記脈波Ｓの振幅Ｗ２に含まれている駆出波成分Ｓ１を除去して、上記反射波成分Ｓ２の基準時間Ｔ２に対応する上記反射波成分Ｓ２の振幅Ｗ３を求める。この反射波成分Ｓ２の基準時間Ｔ２に対応する上記反射波成分Ｓ２の振幅Ｗ３を求める手法としては、例えば、Ｗｉｎｄｋｅｓｓｅｌモデル等を用いて、脈波における駆出波の減少度合いをモデル化し、反射波成分Ｓ２の基準時間Ｔ２の周辺で測定された脈波振幅から駆出波Ｓ１の残存成分を減算する方法等が考えられる。当然ながら、より正確に駆出波Ｓ１の残存成分を特定できる手法があれば採用してもよい。   Further, the ejection wave / reflected wave information extraction unit 120 includes a ejection wave component removal unit 123. As shown in FIG. 4, the ejection wave component removing unit 123 includes the ejection wave included in the amplitude W2 of the pulse wave S from the amplitude W2 of the pulse wave S corresponding to the reference time T2 of the reflected wave component S2. The outgoing wave component S1 is removed, and the amplitude W3 of the reflected wave component S2 corresponding to the reference time T2 of the reflected wave component S2 is obtained. As a method for obtaining the amplitude W3 of the reflected wave component S2 corresponding to the reference time T2 of the reflected wave component S2, for example, the decrease degree of the ejection wave in the pulse wave is modeled using the Windkesel model or the like, and the reflected wave A method of subtracting the remaining component of the ejection wave S1 from the pulse wave amplitude measured around the reference time T2 of the component S2 can be considered. Of course, if there is a technique that can more accurately identify the remaining component of the ejection wave S1, it may be adopted.

ところで、駆出波の伝播速度ＰＷＶｆと反射波の伝播速度ＰＷＶｒを、Ｂramwell-Ｈillの式によって、定式化すると次式(１),(２)のようになる。
ＰＷＶｆ＝{(Ｖ×ΔＰｆ)／(ρ×ΔＶｆ)}１／２ … (１)
ＰＷＶｒ＝{(Ｖ×ΔＰｒ)／(ρ×ΔＶｒ)}１／２ … (２) By the way, when the propagation velocity PWVf of the ejection wave and the propagation velocity PWVr of the reflected wave are formulated by the Bramwell-Hill equation, the following equations (1) and (2) are obtained.
PWVf = {(V × ΔPf) / (ρ × ΔVf)} 1/2 (1)
PWVr = {(V × ΔPr) / (ρ × ΔVr)} 1/2 (2)

次式(１),(２)において、駆出波伝播速度ＰＷＶｆは駆出波のみの脈波伝搬速度、Ｖは血管容積、ρは血液密度、ΔＰｆは駆出波による圧力変化量、ΔＶｆは駆出波による容積変化量である。また、反射波伝播速度ＰＷＶｒは反射波のみの脈波伝搬速度、ΔＰｒは反射波による圧力変化量、ΔＶｒは反射波による容積変化量を表している。   In the following equations (1) and (2), the ejection wave propagation speed PWVf is the pulse wave propagation speed of the ejection wave only, V is the blood vessel volume, ρ is the blood density, ΔPf is the amount of pressure change due to the ejection wave, and ΔVf is Volume change due to ejection wave. The reflected wave propagation speed PWVr represents the pulse wave propagation speed of only the reflected wave, ΔPr represents the pressure change amount due to the reflected wave, and ΔVr represents the volume change amount due to the reflected wave.

この２つの式(１),式(２)をそれぞれ２乗して除算することにより、次式(３)が得られる。
(ＰＷＶｒ)２/(ＰＷＶｆ)２＝(ΔＰｒ×ΔＶｆ)/(ΔＰｆ×ΔＶｒ) … (３) The following equation (3) is obtained by squaring and dividing the two equations (1) and (2).
(PWVr) 2 / (PWVf) 2 = (ΔPr × ΔVf) / (ΔPf × ΔVr) (3)

この式(３)における、ΔＰｒ/ΔＰｆとは、駆出波と反射波の血圧値の比を表している。反射波は、駆出波が腹部・腸骨大動脈のインピーダンス不整合部で反射した波である。このため、上記ΔＰｒ/ΔＰｆは、腹部・腸骨大動脈のインピーダンス不整合部での反射率を表している。非特許文献４(Segers P, Rietzschel ER, et al. , ”Noninvasive (input) impedance, pulse wave velocity, and wave reflection in healthy middle-aged men and women.”, Hypertension.２００７;４９:１２４８-５５.)によると、腹部・腸骨大動脈インピーダンス不整合部での反射率の個人差,年齢差,性差はほとんど無く、反射率は０.４ぐらいということが実験によって確かめられている。   In this equation (3), ΔPr / ΔPf represents the ratio of the blood pressure values of the ejection wave and the reflected wave. The reflected wave is a wave that is reflected from the impedance mismatched part of the abdominal / iliac aorta. Therefore, ΔPr / ΔPf represents the reflectance at the impedance mismatched portion of the abdomen / iliac aorta. Non-Patent Document 4 (Segers P, Rietzschel ER, et al., “Noninvasive (input) impedance, pulse wave velocity, and wave reflection in healthy middle-aged men and women.”, Hypertension. 2007; 49: 1248-55. According to), there are almost no individual differences, age differences, and gender differences in reflectivity at the abdominal / iliac aortic impedance mismatched part, and it has been confirmed by experiments that the reflectivity is about 0.4.

したがって、上式(３)において、(ΔＰｒ/ΔＰｆ)＝ｒ≒０.４とすると、次式(３)’が得られる。
(ＰＷＶｒ)２/(ＰＷＶｆ)２＝ｒ×(ΔＶｆ/ΔＶｒ) … (３)’
≒０.４×(ΔＶｆ/ΔＶｒ) … (３)” Therefore, in the above equation (3), when (ΔPr / ΔPf) = r≈0.4, the following equation (3) ′ is obtained.
(PWVr) 2 / (PWVf) 2 = r × (ΔVf / ΔVr) (3) ′
≒ 0.4 × (ΔVf / ΔVr) (3) "

上述したように、上式(３)’において、ΔＶｆは駆出波による容積変化量であり、ΔＶｒは反射波による容積変化量である。そして、この駆出波による容積変化量ΔＶｆは、上記駆出波成分の基準時間Ｔ１に対応する上記脈波Ｓの駆出波成分Ｓ１の振幅Ｗ１に相当し、上記反射波による容積変化量ΔＶｒは上記反射波成分の基準時間Ｔ２に対応する上記脈波Ｓの反射波成分Ｓ２の振幅Ｗ３に相当している。   As described above, in the above equation (3) ′, ΔVf is the volume change amount due to the ejection wave, and ΔVr is the volume change amount due to the reflected wave. The volume change amount ΔVf due to the ejection wave corresponds to the amplitude W1 of the ejection wave component S1 of the pulse wave S corresponding to the reference time T1 of the ejection wave component, and the volume change amount ΔVr due to the reflected wave. Corresponds to the amplitude W3 of the reflected wave component S2 of the pulse wave S corresponding to the reference time T2 of the reflected wave component.

したがって、上記脈波伝播速度検出部１３０は、上記脈波振幅検出部１２２から得られる上記駆出波成分Ｓ１の時間基準Ｔ１に対応する駆出波成分Ｓ１の振幅Ｗ１を反射波成分Ｓ２の時間基準Ｔ２に対応する反射波成分Ｓ２の振幅Ｗ３を除算することで、上式(３)’の(ΔＶｆ/ΔＶｒ)を算出できる。これにより、上記脈波伝播速度検出部１３０は、上式(３)’から、駆出波伝播速度ＰＷＶｆと反射波伝搬速度ＰＷＶｒとの比率ＰＷＶｒ/ＰＷＶｆを算出できる。   Therefore, the pulse wave propagation velocity detection unit 130 uses the amplitude W1 of the ejection wave component S1 corresponding to the time reference T1 of the ejection wave component S1 obtained from the pulse wave amplitude detection unit 122 as the time of the reflected wave component S2. By dividing the amplitude W3 of the reflected wave component S2 corresponding to the reference T2, (ΔVf / ΔVr) of the above equation (3) ′ can be calculated. Thereby, the pulse wave velocity detection unit 130 can calculate the ratio PWVr / PWVf between the ejection wave propagation velocity PWVf and the reflected wave propagation velocity PWVr from the above equation (3) ′.

次に、上記脈波伝播速度検出部１３０が、上述のように算出した駆出波伝播速度ＰＷＶｆと反射波伝搬速度ＰＷＶｒとの比率(ＰＷＶｒ/ＰＷＶｆ)から、駆出波伝播速度ＰＷＶｆを算出する過程を説明する。   Next, the pulse wave propagation velocity detector 130 calculates the ejection wave propagation velocity PWVf from the ratio (PWVr / PWVf) of the ejection wave propagation velocity PWVf and the reflected wave propagation velocity PWVr calculated as described above. Explain the process.

先ず、前述の如く、容積脈波検出部１１０は、生体の一箇所における測定部位の脈波を検出する。この検出した脈波を基に脈波伝搬速度を同定するために、上記基準時間検出部１２１は、脈波Ｓの駆出波成分Ｓ１の基準時間Ｔ１と脈波Ｓの反射波成分Ｓ２の基準時間Ｔ２とを求める。また、上記脈波振幅検出部１２２は、上記時間基準Ｔ１に対応する駆出波成分Ｓ１の振幅Ｗ１と時間基準Ｔ２に対応する反射波成分Ｓ２の振幅Ｗ３を求める。   First, as described above, the volume pulse wave detection unit 110 detects a pulse wave at a measurement site in one place of the living body. In order to identify the pulse wave propagation speed based on the detected pulse wave, the reference time detection unit 121 determines the reference time T1 of the ejection wave component S1 of the pulse wave S and the reference wave component S2 of the pulse wave S. Time T2 is obtained. Further, the pulse wave amplitude detector 122 obtains the amplitude W1 of the ejection wave component S1 corresponding to the time reference T1 and the amplitude W3 of the reflected wave component S2 corresponding to the time reference T2.

次に、図５に示すように、人体の心臓５１０から腹部大動脈分岐部５２０までの距離をｈ(ｍ)とし、駆出波成分Ｓ１の基準時間Ｔ１と反射波成分Ｓ２の基準時間Ｔ２との時間差(Ｔ２−Ｔ１)をＰＴＴ(秒)とすると、脈波は、２ｈ(ｍ)の距離をＰＴＴ(秒)掛かって伝搬していることになる。よって、脈波伝搬速度ＰＷＶｐは次式(４)によって求めることができる。
ＰＷＶｐ ＝２ｈ/(Ｔ２−Ｔ１)
＝２ｈ/ＰＴＴ … (４) Next, as shown in FIG. 5, the distance from the human heart 510 to the abdominal aorta bifurcation 520 is h (m), and the reference time T1 of the ejection wave component S1 and the reference time T2 of the reflected wave component S2 If the time difference (T2−T1) is PTT (seconds), the pulse wave propagates over a distance of 2h (m) over PTT (seconds). Therefore, the pulse wave propagation speed PWVp can be obtained by the following equation (4).
PWVp = 2h / (T2-T1)
= 2h / PTT (4)

しかし、上式(４)で算出される脈波伝搬速度ＰＷＶｐは、図６に示す駆出波６１０の駆出波伝播速度ＰＷＶｆと反射波６２０の反射波伝搬速度ＰＷＶｒとの速度差が考慮されていない。そこで、脈波伝搬速度ＰＷＶｐは駆出波６１０の駆出波伝播速度ＰＷＶｆと反射波６２０の反射波伝搬速度ＰＷＶｒとを平均した速度と考えると、次式(５)が得られる。
(ＰＷＶｆ＋ＰＷＶｒ)/２＝ＰＷＶｐ … (５) However, the pulse wave propagation speed PWVp calculated by the above equation (4) takes into account the speed difference between the ejection wave propagation speed PWVf of the ejection wave 610 and the reflected wave propagation speed PWVr of the reflected wave 620 shown in FIG. Not. Therefore, when the pulse wave propagation speed PWVp is considered as a speed obtained by averaging the ejection wave propagation speed PWVf of the ejection wave 610 and the reflected wave propagation speed PWVr of the reflected wave 620, the following expression (5) is obtained.
(PWVf + PWVr) / 2 = PWVp (5)

一方、前述のようにして得た駆出波伝播速度ＰＷＶｆと反射波伝搬速度ＰＷＶｒとの比率(ＰＷＶｒ/ＰＷＶｆ)を求める式(３)’から、次式(３)'''が得られる。
ＰＷＶｒ＝(ｒ・(ΔＶｆ/ΔＶｒ))１／２・ＰＷＶｆ … (３)''' On the other hand, from the equation (3) ′ for obtaining the ratio (PWVr / PWVf) between the ejection wave propagation velocity PWVf and the reflected wave propagation velocity PWVr obtained as described above, the following equation (3) ′ ″ is obtained.
PWVr = (r · (ΔVf / ΔVr)) 1/2 · PWVf (3) '''

そして、この式(３)'''による反射波伝搬速度ＰＷＶｒを、上式(５)に代入することにより、駆出波の伝播速度ＰＷＶｆを表す次式(６)が得られる。
ＰＷＶｆ＝{１＋(ｒ・(ΔＶｆ/ΔＶｒ))１／２}−１・２ＰＷＶｐ … (６) Then, by substituting the reflected wave propagation velocity PWVr by the equation (3) ′ ″ into the above equation (5), the following equation (6) representing the ejection wave propagation velocity PWVf is obtained.
PWVf = {1+ (r · (ΔVf / ΔVr)) 1/2 } −1 · 2 PWVp (6)

この式(６)において、ｒは、個人差が殆どなく略一定(例えば、０.４)とみなすことが可能である。また、ΔＶｆは容積脈波における駆出波成分Ｓ１の基準時間Ｔ１での振幅Ｗ１に相当し、ΔＶｒは容積脈波における反射波成分Ｓ２の基準時間Ｔ２での振幅Ｗ３に相当する。また、上記伝播速度ＰＷＶｐは、上述の式(４)から、ＰＷＶｐ＝２ｈ/(Ｔ２−Ｔ１)で算出できる。   In this equation (6), r can be regarded as almost constant (for example, 0.4) with little individual difference. ΔVf corresponds to the amplitude W1 of the ejection wave component S1 in the volume pulse wave at the reference time T1, and ΔVr corresponds to the amplitude W3 of the reflected wave component S2 in the volume pulse wave at the reference time T2. The propagation speed PWVp can be calculated from the above equation (4) by PWVp = 2h / (T2−T1).

このように、上記脈波伝播速度検出部１３０は、駆出波成分Ｓ１の基準時間Ｔ１と反射波成分Ｓ２の基準時間Ｔ２と基準時間Ｔ１に対応する駆出波成分Ｓ１の振幅Ｗ１と基準時間Ｔ２に対応する反射波成分Ｓ２の振幅Ｗ３とに基づいて、駆出波の伝播速度ＰＷＶｆを求めることが可能になる。   In this way, the pulse wave velocity detector 130 determines the reference time T1 of the ejection wave component S1, the reference time T2 of the reflected wave component S2, the amplitude W1 of the ejection wave component S1 corresponding to the reference time T1, and the reference time. Based on the amplitude W3 of the reflected wave component S2 corresponding to T2, the propagation speed PWVf of the ejection wave can be obtained.

ところで、光電脈波形において、上述の如く、光電脈波の駆出波,反射波のそれぞれの基準時間Ｔ１,Ｔ２における振幅Ｗ１,Ｗ３の比率Ｗ１/Ｗ３で容積変化の比率ΔＶｆ/ΔＶｒを代表させた場合、光電脈波形においては、容積変化の比率ΔＶｆ/ΔＶｒを十分正確に同定できない場合もある。   By the way, in the photoelectric pulse waveform, as described above, the volume change ratio ΔVf / ΔVr is represented by the ratio W1 / W3 of the amplitudes W1, W3 at the reference times T1, T2 of the photoelectric pulse ejection wave and the reflected wave, respectively. In this case, the volume change ratio ΔVf / ΔVr may not be identified sufficiently accurately in the photoelectric pulse waveform.

そこで、以下では、光電脈波形において、駆出波,反射波それぞれの血管容積変化ΔＶｆ,ΔＶｒの比率ΔＶｆ/ΔＶｒをより正確に導出する方法について説明する。光電容積脈波法は、拍動による血管容積の変化を光の吸収の変化として検出するものである。   Therefore, hereinafter, a method for more accurately deriving the ratio ΔVf / ΔVr of the blood vessel volume changes ΔVf and ΔVr between the ejection wave and the reflected wave in the photoelectric pulse waveform will be described. The photoelectric volume pulse wave method detects a change in blood vessel volume due to pulsation as a change in light absorption.

一般に或る物質に対して光を入射させた時の光の透過量はランベルト・ベール(Ｌambert-ｂeer)の法則により次式(７)で表すことができる。
log(Ｉｄ/Ｉ０)＝α・ｄ … (７) In general, the amount of transmitted light when light is incident on a certain substance can be expressed by the following equation (7) according to Lambert-Beer's law.
log (Id / I0) = α · d (7)

上式(７)において、Ｉ０は入射光量、Ｉｄは透過光量、ｄは物質の厚み、αは吸光係数である(図７を参照)。   In the above equation (7), I0 is the amount of incident light, Id is the amount of transmitted light, d is the thickness of the substance, and α is the extinction coefficient (see FIG. 7).

生体組織において、７００ｎｍ〜９００ｎｍの波長の光は「生体の窓」とも呼ばれており、生体中の吸光成分は血液中の酸素化ヘモグロビン、および還元ヘモグロビンの２つだけと仮定することができる。また、酸素化ヘモグロビンと還元ヘモグロビンの比率である酸素飽和度は動脈と静脈で異なる。健常時での動脈の酸素飽和度は約９９％であり、静脈の酸素飽和度は約７５％である。   In living tissue, light having a wavelength of 700 nm to 900 nm is also called a “biological window”, and it can be assumed that there are only two light-absorbing components in the living body, oxygenated hemoglobin and reduced hemoglobin in the blood. Further, the oxygen saturation, which is the ratio of oxygenated hemoglobin and reduced hemoglobin, differs between arteries and veins. In normal conditions, arterial oxygen saturation is about 99% and venous oxygen saturation is about 75%.

したがって、生体組織におけるこの波長域での光の吸光量を定式化すると、次式(８)のようになる。
log(Ｉ/Ｉo)＝αＨｂＯ・ｄａ・Ｓａ＋αＨｂ・ｄａ・(１−Ｓａ)
＋αＨｂＯ・ｄｖ・Ｓｖ＋αＨｂ・ｄｖ・(１−Ｓｖ) … (８) Therefore, the following formula (8) is obtained by formulating the light absorption amount in this wavelength region in the living tissue.
log (I / Io) = α HbO · da · Sa + α Hb · da · (1−Sa)
+ Α HbO · dv · Sv + α Hb · dv · (1-Sv) (8)

上式(８)において、Ｉoは光の入射光量、Ｉは光の透過光量、αＨｂＯは酸素化ヘモグロビンの吸光係数、ｄａは動脈の血管径、Ｓａは動脈における酸素飽和度、αＨｂは還元ヘモグロビンの吸光係数、ｄｖは静脈の血管径、Ｓｖは静脈における酸素飽和度を表している。 In the above equation (8), Io is the amount of incident light, I is the amount of transmitted light, α HbO is the absorption coefficient of oxygenated hemoglobin, da is the diameter of the artery, Sa is the oxygen saturation in the artery, and α Hb is the reduction. The extinction coefficient of hemoglobin, dv represents the vein diameter, and Sv represents the oxygen saturation in the vein.

次に、図８Ａに、脈波形８００の極小点８１０,駆出点８２０,反射点８３０を示す。また、図８Ｂ〜図８Ｄに、駆出波,反射波による生体中の血管径の変化と各血管径での透過光量の変化を模式的に示す。図８Ａにおいて、符号８００で示される脈波形は、或る測定部位で測定された光電脈波波形を表している。図８Ａには、光電脈波形８００の極小点８１０、光電脈波形８００の駆出波成分の極大点８２０と、光電脈波形８００の反射波成分の極大点８３０を示している。   Next, FIG. 8A shows a minimum point 810, an ejection point 820, and a reflection point 830 of the pulse waveform 800. 8B to 8D schematically show changes in the blood vessel diameter in the living body due to ejection waves and reflected waves and changes in the amount of transmitted light at each blood vessel diameter. In FIG. 8A, a pulse waveform indicated by reference numeral 800 represents a photoelectric pulse waveform measured at a certain measurement site. FIG. 8A shows a minimum point 810 of the photoelectric pulse waveform 800, a maximum point 820 of the ejection wave component of the photoelectric pulse waveform 800, and a maximum point 830 of the reflected wave component of the photoelectric pulse waveform 800.

また、図８Ｂは、図８Ａの光電脈波形８００の極小点８１０の時点における動脈の血管径ｄａ,静脈の血管径ｄｖと光の透過光量Ｉｍをモデル化した模式図である。また、図８Ｃは、図８Ａの光電脈波形８００の駆出波成分の極大点８２０の時点における血管径(ｄａ＋Δｄｆ),ｄｖと光の透過光量Ｉｆをモデル化した模式図である。また、図８Ｄは、図８Ａの光電脈波形８００の反射波成分の極大点８３０の時点における血管径(ｄａ＋Δｄｒ),ｄｖと光の透過光量Ｉｒをモデル化した模式図である。なお、脈波一拍の期間では、動脈の酸素飽和度Ｓａ、静脈の容積および酸素飽和度量Ｓｖが変化しないと仮定する。   8B is a schematic diagram modeling the arterial blood vessel diameter da, the vein blood vessel diameter dv, and the light transmission amount Im at the time of the local minimum point 810 of the photoelectric pulse waveform 800 of FIG. 8A. FIG. 8C is a schematic diagram modeling the blood vessel diameter (da + Δdf), dv and the light transmission amount If at the time of the maximum point 820 of the ejection wave component of the photoelectric pulse waveform 800 of FIG. 8A. FIG. 8D is a schematic diagram modeling the blood vessel diameter (da + Δdr), dv and the amount of transmitted light Ir at the time of the maximum point 830 of the reflected wave component of the photoelectric pulse waveform 800 of FIG. 8A. It is assumed that the arterial oxygen saturation Sa, the vein volume, and the oxygen saturation amount Sv do not change during the period of one pulse wave.

次に、図８Ｂ,図８Ｃ,図８Ｄの模式図を基に、ランバート・ベールの式により、光の透過量を定式化する。   Next, based on the schematic diagrams of FIGS. 8B, 8 </ b> C, and 8 </ b> D, the light transmission amount is formulated by the Lambert Beer equation.

図８Ａに示す光電脈波８００の極小点８１０では、心臓が収縮し始めた時の血管における光の透過量を測定している(図８Ｂ参照)。その時点での光の吸光量を定式化すると、上式(８)を用いて、次式(９)となる。
log(Ｉｍ/Ｉo)＝αＨｂＯ・ｄａ・Ｓａ＋αＨｂ・ｄａ・(１−Ｓａ)
＋αＨｂＯ・ｄｖ・Ｓｖ＋αＨｂ・ｄｖ・(１−Ｓｖ) … (９) At the minimum point 810 of the photoelectric pulse wave 800 shown in FIG. 8A, the amount of light transmitted through the blood vessel when the heart begins to contract is measured (see FIG. 8B). When the light absorption amount at that time is formulated, the following equation (9) is obtained using the above equation (8).
log (Im / Io) = α HbO · da · Sa + α Hb · da · (1-Sa)
+ Α HbO · dv · Sv + α Hb · dv · (1-Sv) (9)

上式(９)において、Ｉｍは、図８Ａに示す脈波の極小点８１０の時点における透過光量である。   In the above equation (9), Im is the amount of transmitted light at the time of the minimum point 810 of the pulse wave shown in FIG. 8A.

次に、図８Ａに示す光電脈波８００の極大点８２０では駆出波のピーク時での血管における光の透過光量Ｉｆを測定している(図８Ｃ参照)。この極大点８２０において、図８Ｃに示すように、駆出波の圧力変化分だけ血管容積すなわち血管径が変化し、その変化量分Δｄｆだけ光電脈波の透過光量は変化する。すなわち、次式(１０)となる。
log(Ｉｆ/Ｉo)＝αＨｂＯ・(ｄａ＋Δｄｆ)・Ｓａ
＋αＨｂ・(ｄａ＋Δｄｆ)・(１−Ｓａ)
＋αＨｂＯ・ｄｖ・Ｓｖ
＋αＨｂ・ｄｖ・(１−Ｓｖ) … (１０) Next, at the local maximum point 820 of the photoelectric pulse wave 800 shown in FIG. 8A, the transmitted light amount If in the blood vessel at the peak of the ejection wave is measured (see FIG. 8C). At this maximum point 820, as shown in FIG. 8C, the blood vessel volume, that is, the blood vessel diameter, changes by the pressure change of the ejection wave, and the transmitted light amount of the photoelectric pulse wave changes by the change amount Δdf. That is, the following equation (10) is obtained.
log (If / Io) = α HbO · (da + Δdf) · Sa
+ Α Hb · (da + Δdf) · (1-Sa)
+ Α HbO · dv · Sv
+ Α Hb · dv · (1-Sv) (10)

上式(１０)において、Ｉｆは、図８Ａに示す脈波波形８００の駆出波成分の極大点８２０で示す時点における透過光量であり、Δｄｆは駆出波の圧力変化による血管径の変化量である。   In the above equation (10), If is the amount of transmitted light at the time point indicated by the maximum point 820 of the ejection wave component of the pulse wave waveform 800 shown in FIG. 8A, and Δdf is the change amount of the blood vessel diameter due to the pressure change of the ejection wave. It is.

そして、図８Ａに示す光電脈波形の反射波成分の極大点８３０では、反射波のピーク時での血管容積における光の透過光量Ｉｒを測定している(図８Ｄ参照)。この反射波成分の極大点８３０付近では、図８Ｄに示すように、反射波の圧力変化分だけ血管容積すなわち血管径が変化し、この血管径の変化量分Δｄｒだけ光電脈波の透過光量は変化する。
log(Ｉｒ/Ｉo)＝αＨｂＯ・(ｄａ＋Δｄｒ)・Ｓａ
＋αＨｂ・(ｄａ＋Δｄｒ)・(１−Ｓａ)
＋αＨｂＯ・ｄｖ・Ｓｖ
＋αＨｂ・ｄｖ・(１−Ｓｖ) … (１１) Then, at the maximum point 830 of the reflected wave component of the photoelectric pulse waveform shown in FIG. 8A, the amount of transmitted light Ir in the blood vessel volume at the peak of the reflected wave is measured (see FIG. 8D). In the vicinity of the maximum point 830 of the reflected wave component, as shown in FIG. 8D, the blood vessel volume, that is, the blood vessel diameter is changed by the pressure change of the reflected wave, and the transmitted light amount of the photoelectric pulse wave is the change amount Δdr of the blood vessel diameter. Change.
log (Ir / Io) = α HbO · (da + Δdr) · Sa
+ Α Hb · (da + Δdr) · (1-Sa)
+ Α HbO · dv · Sv
+ Α Hb · dv · (1-Sv) (11)

この式(１１)において、Ｉｒは、図８Ａに示す脈波波形８００の反射波成分の極大点８３０の時点における透過光量であり、Δｄｒは反射波の圧力変化による血管径の変化量を示している。   In this equation (11), Ir is the amount of transmitted light at the time of the maximum point 830 of the reflected wave component of the pulse wave waveform 800 shown in FIG. 8A, and Δdr indicates the change amount of the blood vessel diameter due to the pressure change of the reflected wave. Yes.

上述の式(９)、式(１０)、式(１１)を基に、駆出波と反射波の容積変化の比ΔＶｆ/ΔＶｒを求めると以下の式(１２)〜式(１４)のようになる。すなわち、式(９)と式(１０)から次式(１２)が得られ、式(９)と式(１１)から次式(１３)が得られる。
log(Ｉｆ/Ｉo)−log(Ｉｍ/Ｉo)＝αＨｂＯ・Δｄｆ・Ｓａ
＋αＨｂ・Δｄｆ・(１−Ｓａ) …(１２)
log(Ｉｒ/Ｉo)−log(Ｉｍ/Ｉo)＝αＨｂＯ・Δｄｒ・Ｓａ
＋αＨｂ・Δｄｒ・(１−Ｓａ) … (１３) When the ratio ΔVf / ΔVr of the volume change of the ejection wave and the reflected wave is obtained based on the above-described equations (9), (10), and (11), the following equations (12) to (14) are obtained. become. That is, the following equation (12) is obtained from the equations (9) and (10), and the following equation (13) is obtained from the equations (9) and (11).
log (If / Io) −log (Im / Io) = α HbO · Δdf · Sa
+ Α Hb · Δdf · (1-Sa) (12)
log (Ir / Io) −log (Im / Io) = α HbO · Δdr · Sa
+ Α Hb · Δdr · (1-Sa) (13)

そして、式(１２),式(１３)から次式(１４)が得られる。
ΔＶｆ/ΔＶｒ≒Δｄｆ/Δｄｒ＝log(Ｉｆ/Ｉｍ)/log(Ｉｒ/Ｉｍ) … (１４) Then, the following equation (14) is obtained from the equations (12) and (13).
ΔVf / ΔVr≈Δdf / Δdr = log (If / Im) / log (Ir / Im) (14)

したがって、上記脈波振幅検出部１２２により、収縮開始点(光電脈波８００の極小点８１０)での透過光量Ｉｍと、駆出波成分,反射波成分における基準時間Ｔ１,Ｔ２での透過光量Ｉｆ,Ｉｒを検出することによって、上記脈波伝播速度検出部１３０は、上記透過光量Ｉｍ,Ｉｆ,Ｉｒに基づいて上式(１４)から駆出波による容積変化量ΔＶｆと反射波による容積変化量ΔＶｒの比率ΔＶｆ/ΔＶｒを算出することができる。よって、上記脈波伝播速度検出部１３０は、上式(１４)により算出した比率ΔＶｆ/ΔＶｒを上式(６)に代入することにより、駆出波の速度ＰＷＶｆを算出することが可能となる。なお、上記脈波振幅検出部１２２は、上記容積脈波検出部１３０を構成する受光素子が出力する脈波検出信号により、収縮開始時点における透過光量Ｉｍ、駆出波成分,反射波成分における基準時間Ｔ１,Ｔ２における透過光量Ｉｆ,Ｉｒを検出できる。   Therefore, the pulse wave amplitude detection unit 122 causes the transmitted light amount Im at the contraction start point (minimum point 810 of the photoelectric pulse wave 800) and the transmitted light amount If at the reference times T1 and T2 in the ejection wave component and the reflected wave component. , Ir, the pulse wave velocity detector 130 detects the volume change ΔVf due to the ejection wave and the volume change due to the reflected wave from the above equation (14) based on the transmitted light amounts Im, If, Ir. The ratio ΔVf / ΔVr of ΔVr can be calculated. Therefore, the pulse wave propagation velocity detection unit 130 can calculate the ejection wave velocity PWVf by substituting the ratio ΔVf / ΔVr calculated by the above equation (14) into the above equation (6). . The pulse wave amplitude detection unit 122 uses the pulse wave detection signal output from the light receiving element constituting the volume pulse wave detection unit 130 as a reference for the transmitted light amount Im, ejection wave component, and reflected wave component at the start of contraction. The transmitted light amounts If and Ir at times T1 and T2 can be detected.

１００ 脈波伝播速度測定装置
１１０ 容積脈波検出部
１２０ 駆出波・反射波情報抽出部
１２１ 基準時間検出部
１２２ 脈波振幅検出部
１２３ 駆出波成分除去部
１３０ 脈波伝播速度検出部
５１ 心臓
５３ 腹部大動脈分岐部
ｈ 心臓から腹部大動脈分岐部までの距離
Ｑ１ 収縮期の極大点
Ｑ２ ４次微分波の第３ゼロクロスポイント
Ｓ 脈波
Ｓ１ 駆出波成分
Ｓ２ 反射波成分
Ｔ１ 駆出波成分の基準時間
Ｔ２ 反射波成分の基準時間
Ｗ１ 基準時間Ｔ１に対応する脈波Ｓ(駆出波成分Ｓ１)の振幅
Ｗ２ 基準時間Ｔ２に対応する脈波Ｓの振幅
Ｗ３ 基準時間Ｔ２に対応する反射波成分Ｓ２の振幅 100 Pulse Wave Propagation Speed Measuring Device 110 Volume Pulse Wave Detection Unit 120 Ejection Wave / Reflected Wave Information Extraction Unit 121 Reference Time Detection Unit 122 Pulse Wave Amplitude Detection Unit 123 Ejection Wave Component Removal Unit 130 Pulse Wave Propagation Speed Detection Unit 51 Heart 53 Abdominal aortic bifurcation h Distance from heart to abdominal aortic bifurcation Q1 Maximum point Q2 during systole Third zero cross point S of the 4th derivative wave Pulse wave S1 Ejection wave component S2 Reflected wave component T1 Reference of ejection wave component Time T2 Reference time W1 of reflected wave component Amplitude W2 of pulse wave S (ejection wave component S1) corresponding to reference time T1 Amplitude W3 of pulse wave S corresponding to reference time T2 Reflected wave component S2 corresponding to reference time T2 Amplitude of

Claims (5)

生体の或る一部位における容積脈波を検出する容積脈波検出部と、
上記容積脈波検出部で検出した上記一部位における容積脈波に含まれる駆出波成分を特定するための基準時間と上記容積脈波に含まれる反射波成分を特定するための基準時間とを検出する基準時間検出部と、
上記容積脈波検出部で検出した容積脈波に基づいて、上記基準時間検出部で検出した上記駆出波成分の基準時間に対応する上記駆出波成分による血管の容積の変化量と、上記基準時間検出部で検出した上記反射波成分の基準時間に対応する上記反射波成分による血管の容積の変化量を検出する容積変化量検出部と、
上記基準時間検出部で検出した上記駆出波成分の基準時間および上記反射波成分の基準時間と、上記容積変化量検出部で検出した上記駆出波成分による血管の容積の変化量および上記反射波成分による血管の容積の変化量とに基づいて、上記容積脈波の駆出波の伝播速度を求める伝播速度検出部とを備えることを特徴とする脈波伝播速度測定装置。 A volume pulse wave detector for detecting a volume pulse wave in a certain part of the living body;
A reference time for specifying the ejection wave component included in the volume pulse wave at the partial position detected by the volume pulse wave detection unit and a reference time for specifying the reflected wave component included in the volume pulse wave A reference time detection unit to detect;
Based on the volume pulse wave detected by the volume pulse wave detection unit, the change amount of the volume of the blood vessel due to the ejection wave component corresponding to the reference time of the ejection wave component detected by the reference time detection unit, and A volume change amount detecting unit for detecting a change amount of a blood vessel volume due to the reflected wave component corresponding to a reference time of the reflected wave component detected by a reference time detecting unit;
The reference time of the ejection wave component and the reference time of the reflected wave component detected by the reference time detection unit, the change amount of the blood vessel volume by the ejection wave component detected by the volume change amount detection unit, and the reflection A pulse wave velocity measuring apparatus, comprising: a propagation velocity detector that obtains the propagation velocity of the ejection pulse of the volume pulse wave based on a change amount of a blood vessel volume due to a wave component. 請求項１に記載の脈波伝播速度測定装置において、
上記伝播速度検出部は、
上記容積変化量検出部で検出した上記駆出波成分による血管の容積の変化量と上記反射波成分による血管の容積の変化量との比率を求め、この比率と上記基準時間検出部で検出した上記駆出波成分の基準時間および上記反射波成分の基準時間に基づいて、上記容積脈波の駆出波の伝播速度を求めることを特徴とする脈波伝播速度測定装置。 In the pulse wave velocity measuring device according to claim 1,
The propagation velocity detector is
The ratio of the change amount of the blood vessel volume due to the ejection wave component detected by the volume change amount detection unit and the change amount of the blood vessel volume due to the reflected wave component is obtained, and this ratio and the reference time detection unit detect A pulse wave velocity measuring apparatus, characterized in that the velocity of ejection of the volume pulse wave is determined based on the reference time of the ejected wave component and the reference time of the reflected wave component. 請求項１に記載の脈波伝播速度測定装置において、
上記容積脈波検出部が検出する容積脈波は、生体の或る一部位における光電容積脈波であることを特徴とする脈波伝播速度測定装置。 In the pulse wave velocity measuring device according to claim 1,
2. The pulse wave velocity measuring apparatus according to claim 1, wherein the volume pulse wave detected by the volume pulse wave detection unit is a photoelectric volume pulse wave in a certain part of a living body. 請求項３に記載の脈波伝播速度測定装置において、
上記伝播速度検出部は、
上記容積変化量検出部で検出した上記駆出波成分による血管の容積の変化量と上記反射波成分による血管の容積の変化量との比率を求め、この比率と上記基準時間検出部で検出した上記駆出波成分の基準時間および上記反射波成分の基準時間に基づいて、上記容積脈波の駆出波の伝播速度を求めることを特徴とする脈波伝播速度測定装置。 In the pulse wave velocity measuring device according to claim 3,
The propagation velocity detector is
The ratio of the change amount of the blood vessel volume due to the ejection wave component detected by the volume change amount detection unit and the change amount of the blood vessel volume due to the reflected wave component is obtained, and this ratio and the reference time detection unit detect A pulse wave velocity measuring apparatus, characterized in that the velocity of ejection of the volume pulse wave is determined based on the reference time of the ejected wave component and the reference time of the reflected wave component. 請求項４に記載の脈波伝播速度測定装置において、
上記伝播速度検出部は、
上記容積変化量検出部で検出した上記光電容積脈波の極小点で値と上記駆出波成分の基準時間での上記光電容積脈波の値と上記反射波成分の基準時間での上記光電容積脈波の値とに基づいて、上記駆出波成分による血管の容積の変化量と上記反射波成分による血管の容積の変化量との比率を求め、この比率と上記基準時間検出部で検出した上記駆出波成分の基準時間および上記反射波成分の基準時間に基づいて、上記容積脈波の駆出波の伝播速度を求めることを特徴とする脈波伝播速度測定装置。 In the pulse wave velocity measuring device according to claim 4,
The propagation velocity detector is
The value of the photoelectric volume pulse wave detected at the minimum amount of the photoelectric volume pulse wave, the value of the photoelectric volume pulse wave at the reference time of the ejection wave component, and the photoelectric volume at the reference time of the reflected wave component Based on the value of the pulse wave, a ratio between the change amount of the blood vessel volume due to the ejection wave component and the change amount of the blood vessel volume due to the reflected wave component is obtained, and this ratio and the reference time detection unit detect A pulse wave velocity measuring apparatus, characterized in that the velocity of ejection of the volume pulse wave is determined based on the reference time of the ejected wave component and the reference time of the reflected wave component.
JP2010234570A 2010-10-19 2010-10-19 Pulse wave velocity measuring device Expired - Fee Related JP5690550B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2010234570A JP5690550B2 (en) 2010-10-19 2010-10-19 Pulse wave velocity measuring device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2010234570A JP5690550B2 (en) 2010-10-19 2010-10-19 Pulse wave velocity measuring device

Publications (2)

Publication Number Publication Date
JP2012085792A true JP2012085792A (en) 2012-05-10
JP5690550B2 JP5690550B2 (en) 2015-03-25

Family

ID=46258103

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2010234570A Expired - Fee Related JP5690550B2 (en) 2010-10-19 2010-10-19 Pulse wave velocity measuring device

Country Status (1)

Country Link
JP (1) JP5690550B2 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2017536885A (en) * 2014-10-27 2017-12-14 グッドマン，ジェッセ System and method for monitoring aortic pulse wave velocity and blood pressure
JP2019058653A (en) * 2017-09-22 2019-04-18 学校法人都築第一学園 Pulse wave velocity measurement apparatus

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003010139A (en) * 2001-07-02 2003-01-14 Nippon Colin Co Ltd Measuring device for information on pulse wave propagation speed
JP2003250769A (en) * 2002-03-01 2003-09-09 Nippon Colin Co Ltd Arteriosclerosis examination instrument
JP2004113593A (en) * 2002-09-27 2004-04-15 Nippon Colin Co Ltd Apparatus for evaluating arteriosclerotic degree
JP2007007075A (en) * 2005-06-29 2007-01-18 Fukuda Denshi Co Ltd Blood pressure measuring apparatus
JP2008302127A (en) * 2007-06-11 2008-12-18 Denso Corp Blood pressure measuring apparatus, program, and recording medium
JP2009082175A (en) * 2007-09-27 2009-04-23 Omron Healthcare Co Ltd Respiration training instrument and computer program
JP2010194108A (en) * 2009-02-25 2010-09-09 Omron Healthcare Co Ltd Blood pressure information measuring device and calculation program for arteriosclerosis degree index
JP2012070876A (en) * 2010-09-28 2012-04-12 Omron Healthcare Co Ltd Blood pressure information measurement device and method for calculating index for degree of arteriosclerosis using the device

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003010139A (en) * 2001-07-02 2003-01-14 Nippon Colin Co Ltd Measuring device for information on pulse wave propagation speed
JP2003250769A (en) * 2002-03-01 2003-09-09 Nippon Colin Co Ltd Arteriosclerosis examination instrument
JP2004113593A (en) * 2002-09-27 2004-04-15 Nippon Colin Co Ltd Apparatus for evaluating arteriosclerotic degree
JP2007007075A (en) * 2005-06-29 2007-01-18 Fukuda Denshi Co Ltd Blood pressure measuring apparatus
JP2008302127A (en) * 2007-06-11 2008-12-18 Denso Corp Blood pressure measuring apparatus, program, and recording medium
JP2009082175A (en) * 2007-09-27 2009-04-23 Omron Healthcare Co Ltd Respiration training instrument and computer program
JP2010194108A (en) * 2009-02-25 2010-09-09 Omron Healthcare Co Ltd Blood pressure information measuring device and calculation program for arteriosclerosis degree index
JP2012070876A (en) * 2010-09-28 2012-04-12 Omron Healthcare Co Ltd Blood pressure information measurement device and method for calculating index for degree of arteriosclerosis using the device

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2017536885A (en) * 2014-10-27 2017-12-14 グッドマン，ジェッセ System and method for monitoring aortic pulse wave velocity and blood pressure
US11246495B2 (en) 2014-10-27 2022-02-15 Vital Sines International Inc. System and method for monitoring aortic pulse wave velocity and blood pressure
JP2019058653A (en) * 2017-09-22 2019-04-18 学校法人都築第一学園 Pulse wave velocity measurement apparatus
JP7212218B2 (en) 2017-09-22 2023-01-25 学校法人都築第一学園 pulse wave velocity measuring device

Also Published As

Publication number Publication date
JP5690550B2 (en) 2015-03-25

Similar Documents

Publication Publication Date Title
US11350825B2 (en) Contactless system and method for measuring and continuously monitoring arterial blood pressure
US10709424B2 (en) Method and system for cuff-less blood pressure (BP) measurement of a subject
JP5318810B2 (en) Pulse wave velocity measuring device, pulse wave velocity measuring method, and pulse wave velocity measuring program
Husmann et al. Markers of arterial stiffness in peripheral arterial disease
JP5328613B2 (en) Pulse wave velocity measuring device and pulse wave velocity measuring program
Baruch et al. Validation of the pulse decomposition analysis algorithm using central arterial blood pressure
US8273030B2 (en) Method of estimating pulse wave velocity
US11154208B2 (en) System and method of measurement of average blood pressure
Rachim et al. Wrist photo-plethysmography and bio-impedance sensor for cuff-less blood pressure monitoring
Sondej et al. Validation of a new device for photoplethysmographic measurement of multi-site arterial pulse wave velocity
JP5681434B2 (en) Pulse wave velocity measuring device and pulse wave velocity measuring program
Rasool et al. Continuous and noninvasive blood pressure estimation by two-sensor measurement of pulse transit time
JP5690550B2 (en) Pulse wave velocity measuring device
Li et al. Initial study on pulse wave velocity acquired from one hand using two synchronized wireless reflectance pulse oximeters
Almeida et al. Hemodynamic features extraction from a new arterial pressure waveform probe
Laurent How to assess vascular aging
Baruch Pulse decomposition analysis techniques
Manoj et al. Measurement of Local Pulse Wave Velocity: Agreement Among Various Methodologies
Qawqzeh et al. Photoplethysmogram reflection index and aging
Manimegalai et al. An early prediction of cardiac risk using augmentation index developed based on a comparative study
Hashuro et al. Changes of Arterial stiffness during flow-mediated dilation procedure
Markina et al. Spectral method of photoplethysmogram processing for screening of atherosclerosis
Gonzalez et al. Photoplethysmographic augmentation index using the signal fourth derivative
Kim et al. A Vascular Characteristic Index of Blood Pressure Variation using the Pulse Wave Signal
Sudarsan et al. Assessment of Endothelial Reactivity using Brachial Pulse Wave Velocity Response to Shear

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20131001

A977 Report on retrieval

Free format text: JAPANESE INTERMEDIATE CODE: A971007

Effective date: 20140528

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20140603

A521 Written amendment

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20140724

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20150106

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20150202

R150 Certificate of patent or registration of utility model

Ref document number: 5690550

Country of ref document: JP

Free format text: JAPANESE INTERMEDIATE CODE: R150

LAPS Cancellation because of no payment of annual fees