JP2753829B2 - Blood pressure measurement device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a non-invasive sphygmomanometer, which is mounted on a part of a living body, and a pressurizing means is applied to a part of the sphygmomanometer so that the pressure and the inside of a blood vessel can be measured. Vascular diameter (volume) that changes with pressure
And an apparatus for detecting blood pressure by optical means to measure blood pressure. 2. Description of the Related Art Conventionally, indirectly measuring blood pressure with a finger or the like as in this type of sphygmomanometer is meaningful because it is simple. For example, (1), in U.S. Pat. No. 4,406,289, a servo balance technique is used. On the other hand, (2) In another example, as shown in US Pat. No. 4,597,393, a method of estimating the diastolic blood pressure by calculating the elasticity of the blood vessel and the surrounding tissue assuming that the elasticity is linear is also known. is there. (3) In another example, US Pat. No. 3,104,661
No. 3,920,004 and No. 4,437,470, there is also a method using a plurality of cuffs and sensors. (Problems to be Solved by the Invention) However, in the case of the conventional (1), the device is large-scale, and time is required for mounting and adjusting at the time of mounting, and it is not suitable for applications where blood pressure is to be measured at any time. There was a problem.
In addition, in the case of (2), in addition to the error due to linearity, when calculating the area of a minute waveform, the data amount increases, and when the data amount is reduced,
It has problems such as errors that occur. Next, in the case of (3), pressurization is not allowed because two or more objects need to be mounted and the pressurization of the peripheral detector may cause an error. In determining the diastolic blood pressure, there have been problems such as the inability to determine it or the determination logic being ambiguous. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a highly accurate blood pressure measurement device with a simple configuration by solving the problems caused by the measurement accuracy and the complexity of the device, which the prior art has. (Means for Solving the Problems) In order to achieve the above object, a first embodiment of the present invention is a blood pressure measurement device which is attached to a part of a living body and performs non-invasive blood pressure measurement. By pressurizing a part of the living body and then reducing the pressure, a pressure increasing / decreasing means for generating a diametrical shape change in a blood vessel, and disposed on a peripheral side of the living body,
A first optical detecting means, comprising a first light emitting unit and a first light receiving unit, for optically detecting a change in the diameter of the blood vessel in the diametrical direction; And a second light receiving unit, wherein the second optical detection means for optically detecting a change in the shape of the blood vessel in the diameter direction, and the first light emitting unit and the second light receiving unit in a state where extraneous light is blocked. Switching operation means for operating the first optical detection means and the second optical detection means in a time-division manner by alternately lighting the light-emitting portions of the first and second optical detection means, and a detection signal of the first optical detection means. Blood pressure measuring device, comprising: a control judging unit for measuring a diastolic blood pressure and a diastolic blood pressure by comparing a detection signal of the first optical detection unit with a detection signal of the second optical detection unit. It is characterized by the following. A second embodiment of the present invention is a blood pressure measurement device which is attached to a part of a living body and performs non-invasive blood pressure measurement. And a first light-emitting unit and a first light-receiving unit, which are arranged on the distal side of the living body and optically detect the change in the diameter of the blood vessel. A first optical detecting means for detecting the blood vessel, a second light emitting section and a second light receiving section disposed on the heart side of the living body, and optically detecting a change in the diameter of the blood vessel in the second direction. The first optical detection means and the first
By providing a period in which the light-emitting unit and the second light-emitting unit are simultaneously inactive, and alternately turning on the first light-emitting unit and the second light-emitting unit, the first optical Switching operating means for alternately operating the detecting means and the second optical detecting means in a time-sharing manner; and a second operating means obtained respectively in an operating state of the first optical detecting means and the second optical detecting means. External light that removes the influence of the external light based on a difference operation between the first detection signal and a second detection signal that is obtained when the first light emitting unit and the second light emitting unit are not operated. Removing means for calculating the systolic blood pressure from the detection signal of the first optical detection means from which the extraneous light has been removed by calculation by the extraneous light removing means; Ratio of detection signals of optical detection means and the second optical detection means And it is characterized in the blood pressure measuring apparatus characterized by having a determining means for determining diastolic blood pressure by the value. Further, according to the present invention, in the blood pressure measurement device according to the first or second embodiment, at the time of starting pressurization of the pressurizing / depressurizing means, the first pressure is not more than the average diastolic blood pressure.
The gain of the detection signal of the first optical detection means or the gain of the detection signal of the second optical detection means is adjusted so that the detection value of the optical detection means is equal to the detection value of the second optical detection means. It is preferable to provide an adjusting means for performing the adjustment. Next, the present invention will be described in detail with reference to the drawings corresponding to the embodiments. The first invention is a non-invasive sphygmomanometer as shown in FIG. 2, which is mounted on a finger F of a living body and pressurizes a part of them, and a pressure is applied to the pressurizing means. A blood pressure monitor comprising means S for supplying and reducing pressure, and optical means Ea, Eb and Da, Db for detecting a change in blood vessel diameter (volume) which changes due to the applied pressure and the internal pressure of the blood vessel A.
As shown in the figure, (1), a plurality of light emitting units Ea and Eb of optical means and conventional techniques Da and Db are provided. (2) The second optical detecting means including the light emitting element Ea and the light receiving element Da is disposed closer to the heart than the first optical detecting means including the light emitting element Eb and the light receiving element Db (FIG. 2). reference). (3) The plurality of optical means are operated in a time-division manner. (4) These optical means block external light. (5) As shown in FIG. 1, there is provided a means Cp for comparing the outputs of two or more optical means (Ea, Da) and (Eb, Db) which are located on the cardiac side and the peripheral side. The systolic blood pressure is determined by the appearance point of the output Ss of the optical means (Eb, Db) located on the peripheral side, and the diastolic blood pressure is determined when the output Sd of the comparing means Cp disappears. . The second invention has exactly the same configuration as the detection unit of the first invention, but has no shielding and receives light from the outside at the light receiving elements Da and Db. As shown in FIG. There are a plurality of light emitting units Ea and Eb and light receiving units Da and Db. (2) The second optical detecting means including the light emitting element Ea and the light receiving element Da is disposed closer to the heart than the first optical detecting means including the light emitting element Eb and the light receiving element Db. (3) The plurality of optical means are operated in a time-division manner as shown in FIG.
It has a phase in which all light emission stops. (4) Means for storing the light receiving signal at the time of rest by the capacitors Ca, Cb, etc., and subtracting the stored signal from the signal at the time of light emission (differential amplifiers A ₃₁ , A
₃₂ ) and (5) the relationship between the heart and the periphery 2
A means Cp for comparing the outputs of two or more optical means (Ea, Da) and (Eb, Db), and the systolic blood pressure is the point of appearance of the output Ss of the optical means (Eb, Eb) located on the peripheral side And the diastolic blood pressure is determined when the output Sd of the comparison means Cp disappears. The third invention is an additional invention of the first and second inventions,
Figure 7, as shown in FIG. 8, FIG. 1, the signal Sa in Fig. 6 ', Sb' variable gain amplifier A ₄ is added to either of, first, the diastolic blood pressure clearly smaller pressure value than (E.g., 30 mmHg), a closed-loop control circuit that controls the gain so that both signals Sa 'and Sb' are equal to each other is temporarily activated so that the diastolic blood pressure can be accurately measured. is there. (Operation) When the first invention and the second invention are configured as described above, the bladder B is once pressurized by the pressurizing means S to a pressure higher than the systolic blood pressure, and then gradually depressurized by the depressurizing means S.
As shown in FIG. 4, the change in the blood vessel volume is represented by the signals Sa 'and Sb'.
Changes as shown in FIG. Therefore, when the bladder pressure is higher than the systolic blood pressure, the blood vessel remains closed and there is no blood flow (see FIG. 4 (a)).
Since there is no blood flow, the peripheral vascular volume does not change and the light Lb does not change, but the cardiac vascular volume changes and the light La changes. That is, there is no signal Sb 'and a signal Sa' is generated (left side in FIG. 5). When the bladder pressure is slightly lower than the systolic blood pressure, the blood vessels are opened only during a period in which the internal pressure is higher than the external pressure, and a blood flow occurs (see FIG. 4 (b)). As a result, a change appears in the light Lb, and a signal Sb 'is generated (see the systolic blood pressure point in FIG. 5). When the bladder pressure falls below the minimum blood pressure, there is no longer a period in which the blood vessels are closed (see FIG. 4 (c)), the changes to the light La and Lb are equal, and the signals Sa 'and Sb' are equal. Then, the comparing means Cp compares the signals Sa 'and Sb' and outputs the difference Sd, so that the output becomes zero at the diastolic blood pressure (see the diastolic blood pressure point in the lower part of FIG. 5). In this way, the systolic blood pressure is obtained from the appearance point of the signal Sb ′, and
The diastolic blood pressure can be determined from the point at which the signal Ss of the difference between Sa 'and Sb' disappears. According to the third invention, waveforms are output from two positions for determining the diastolic blood pressure because there is variation in not only the cause on the living body side but also the cause on the device side, for example, the sensitivity of the light receiving element by the LED of the light emitting element or the phototransistor. In order to make the coincidence of the signals more complete, the gain is controlled in advance so that the signals Sa 'and Sb' are equal to each other, and the operation is performed at once. Therefore, the accuracy of the diastolic blood pressure can be measured with good accuracy. (Embodiment) FIG. 2 is a partially cutaway sectional view showing the structure of a detection unit according to the present invention. F is a human finger showing a left half in a sectional view, A is an artery in a finger F of a living body, and B is a finger. Is a bladder that gives air pressure to the finger F,
C is a cuff that limits the inflation of bladder B, S is bladder B
Ea and Eb indicate light emitting elements such as infra-red LEDs, for example, and Da and Db indicate light receiving elements such as phototransistors. In the figure, the light emitting element Ea and the light receiving element Da are arranged to face each other, and the light emitting element Ea
Of light reach through the fingers (including the arteries). For example, if bladder B is opaque, it is placed between finger F and bladder B. However, if bladder B is transparent, the inner surface of bladder B or the middle between bladder B and cuff C may be used. In addition, the light emitting element Eb and the light receiving element Da are similarly placed facing each other. However, the light-emitting element Ea and the light-receiving element Da are located closer to the heart than the center of the bladder B, and the light-emitting element Eb and the light-receiving element Db are located more distally than the center of the bladder B.
The light La that exits the light emitting element Ea and reaches the light receiving element Da changes the amount of light blocked by a volume change according to the internal pressure of the artery (blood vessel) A, and outputs a signal to the light receiving element Da. Similarly, a signal output of a change in arterial volume is obtained from the light receiving element Db by the light Lb emitted from the light emitting element Eb. In this case, if an external light component is received by the light emitting element and the light receiving element, an error may occur in the measurement. Therefore, as a method for avoiding the occurrence of this error, the first invention protects the optical means by blocking extraneous light. For example, gloves are worn. Next, in the second invention, even if external light is received, it is electrically removed. First, the first invention will be described. In this case, the light emitting elements Ea and Eb emit light alternately by a two-phase clock so that the light emitting times do not overlap. The light receiving elements Da and Db are switched in synchronization with the clock of light emission,
Light-receiving signals of only the light La and Lb of the light-emitting elements Ea and Eb facing each other are received. Note that the blinking frequency of these lights is 60 times or more the maximum pulse rate expected to reproduce a correct pulse waveform. Next, the operation will be described with reference to the circuit diagram of FIG. First, the light emitting element Ea emits light through the switch SW ₁₁ in the phase P _1, the light receiving element Da is because it is shielded from external light, and receives only the light La from the light emitting element Ea. This is replaced by a voltage signal, the signal Sa is amplified by an amplifier A ₁
Becomes Next, the light emitting element Eb similar to the emits light in phase P _2, the light receiving element Db receives light Lb, the voltage signal Sb.
These signal voltages Sa and Sb are detected by detectors D ₁ and D ₂ . That is, the carrier clock component is removed, and signals Sa 'and Sb' corresponding to the change in the volume of the blood vessel are obtained. Then, the signals Sa 'and Sb' are compared by the comparator Cp, and the difference Sd is output. Therefore, when the amplitudes of both waveforms match, the output becomes zero. In the above configuration, the systolic blood pressure (SY-STOLI)
C) How the diastolic blood pressure (DIASTOLIC) is determined will be described with reference to FIGS. 4 and 5. First, the bladder B is once pressurized by the pressurizing means S to a pressure higher than the systolic blood pressure. Next, the pressure is gradually reduced by the pressure reducing means S. At this time, the blood vessel volume change is as shown in FIG.
As shown in FIGS. 5B and 5C, the signals Sa 'and Sb' change as shown in FIG. That is, when the bladder pressure is higher than the systolic blood pressure, the blood vessel remains occluded and there is no blood flow (fourth blood pressure).
FIG. (A)). Therefore, since there is no blood flow, the blood vessel volume does not change on the peripheral side and there is no change for the light Lb, but the blood vessel volume on the heart side changes and the light La changes. That is, the signal
There is no Sb ', and a signal Sa' is generated (see the left side of FIG. 5). Then, when the bladder pressure is slightly lower than the systolic blood pressure, the blood vessel opens only during a period in which the internal pressure is higher than the external pressure, and a blood flow occurs (see FIG. 4 (b)). As a result, a change with respect to the light Lb appears, and a signal Sb 'is generated (FIG. 5: SYSTOL).
IC). Next, when the bladder pressure falls below the minimum blood pressure, there is no longer a period in which the blood vessels are closed (see FIG. 4 (c)), and the changes to the light La and Lb become equal. That is, the signals Sa 'and Sb' are also equal. Accordingly, since the comparator Cp compares the signals Sa 'and Sb' and outputs the difference Sd, the output becomes zero at the lowest blood pressure (see the lower DIASTOLIC in FIG. 5). In this way, the systolic blood pressure can be determined from the appearance point of the signal Sb ', and the diastolic blood pressure can be determined from the point at which the signal Sd of the difference between the signals Sa' and Sb 'disappears. Next, the second invention will be described. The detector of FIG. 2 has exactly the same configuration as that of the first invention, and its outside is not shielded. Therefore, the light receiving elements Da and Db also receive light from outside. In this case, the light emitting elements Ea and Eb emit light by the multi-phase clock so that the light emitting times do not overlap.
The light receiving elements Da and Db are switched in synchronization with the clock of light emission. The phase P ₁ in the light-emitting element Ea as shown in Figure 3 to emit light, and light emission phase P ₂ in the light-emitting element Eb is the phase P ₃
Then neither emits light. The flashing frequency of these lights is 60 times or more the maximum pulse rate expected to reproduce the correct pulse waveform. Note In the phase P ₃ of the light emitting element Ea, both Eb does not emit light receiving element Da, Db is receiving external light Lc. That is, ambient light (light illumination or sunlight) illuminates the finger F, and at both ends of the cuff C, the light is scattered by the tissue of the finger F and reaches the light receiving elements Da and Db. This is Lc
And Next, the operation will be described with reference to FIG. Signals obtained by the light receiving element Da is amplified by an amplifier A _1, it is guided to the differential amplifier A ₃₁ via the switch SW _12.
In this case, when describing the operation of the switch SW _11, SW ₁₂ and the differential amplifier A _31, the light emitting element Ea emits light via the switch SW ₁₁ is at the position P _1. The light receiving element Da receives the light La from the light emitting element Ea, but also receives the external light Lc at the same time. That receives light La + Lc in phase P _1. This is replaced by a voltage signal is amplified by an amplifier A _1, the signal Sa + Sc
Becomes Then, in the phase P _2, the same, the light emitting element Eb emits light, the light receiving element Db is a voltage signal by receiving light Lb + Lc Sb + Sc
Becomes While still in the phase P ₃ receives only the light Lc as described above, the switch SW ₃₁ signal Sc is in this case, SW ₃₂
Connected to the non-inverting input sides of the two differential amplifiers A ₃₁ and A ₃₂ respectively. However, Kiyapashita Ca to the non-inverting input terminal, since Cb is connected, the signal voltage at this time is maintained even after the completion of the phase P ₃ to the non-inverting input. Further, the inverting input of the differential amplifier A ₃₁ is the signal Sa + Sc in phase P _1, is connected by a switch SW _31, the difference between the but connexion differential amplifier A ₃₁ both inputs, i.e. Sc- (Sa + Sc) = - S
Output the signal of a. Similarly, the differential amplifier A ₃₂ also in the phase P ₂ is Sc- (Sb + Sc) = - outputs a signal Sb. As described above, only the signal component from which the signal Sc due to extraneous light has been removed is output to the outputs of the differential amplifiers A ₃₁ and A ₃₂ . Next, the signal outputs Sa and Sb are detected by detectors D ₁ and D ₂ . That is, the carrier clock component is removed, and signals Sa 'and Sb' corresponding to the change in the volume of the blood vessel are obtained. The above is the first
The signals Sa 'and Sb' are compared by the same comparator Cp as in the invention of the first embodiment, and the difference Sd is output. Therefore, when the amplitudes of both waveforms match, the output becomes zero. In the above configuration, the systolic blood pressure (SY-STOLI)
C) How the diastolic blood pressure (DIASTOLIC) is determined is exactly the same as that in the first invention, and the description is omitted. According to the above apparatus, the diastolic blood pressure can be measured with high accuracy. However, in order to more completely match the waveform outputs from the two positions for determining the diastolic blood pressure due to, for example, variations in elements, factors on the living body side, and the like. The improvement of is described below. FIG. 7 is a circuit diagram thereof, and FIG. 8 is an explanatory diagram of the operation thereof. In the figure, signals Sa 'and Sb' are signals corresponding to the change in the volume of the blood vessel shown in FIG.
One of through the variable gain amplifier A _4, and inputs to the comparator circuit Cp of FIG. 1. Then, as both signals become equal, control the gain of the variable gain amplifier A _4. That is, the comparator Cp
The output from through the amplifier A ₅ is temporarily operate the closed loop control that is connected to the variable gain amplifier A _4. This is performed when a pressure value Pc (for example, 30 mmHg), which is clearly lower than the diastolic blood pressure, is reached at the beginning of pressurization in the pressurization / decompression process as shown in FIG. At this time, pressurization is stopped for t hours to keep the pressure constant. The reason is that the signals Sa 'and Sb' must be equal below the diastolic blood pressure. That is, the output of the comparison circuit Cp must be zero. However, if the signals Sa 'and Sb' are not equal, the output of the comparison circuit Cp is not zero. If zero plus the output of the comparator circuit Cp to the variable gain amplifier A _4, the output of the controlled gain comparator circuit Cp is controlled to be zero. This control value is stored and held, for example, in the battery Cc until the measurement is completed. Then, as soon as the holding is performed, the pressure is increased again, and after the pressure is increased to be higher than the systolic blood pressure, the measurement is started as described above. The variable gain amplifier may employ a method in which, for example, a resistor for determining the gain of the amplifier is selected by a switch. Further, the switch can be controlled by a digital signal. This method absorbs not only the cause on the living body side but also the cause on the device side, for example, variations in the sensitivity of the LED and the phototransistor. The idea of seeing the output of the two sets of optical systems coincide at low pressure can also be realized by other means. An example is described below. That is, as shown in the ninth input, a part of the analog means is replaced by digital means. That is, the optical means is the same as that described in FIGS. 1 and 6,
It does not have the differential amplifiers A ₃₁ and A ₃₂ , the detection circuits D ₁ and D ₂ , and the comparison circuit Cp. These functions are performed digitally. That is, each output of the two sets of optical means is an A / D converter C
It is converted at t and stored in the memory M as a digital quantity. Of course, the output when the light-emitting element in the phase P ₃ does not emit light are also stored separately. Further, role of the differential amplifier A _31, A ₃₂ is a removal of the influence of the external light, which is the signal in the phase P _1, it is to subtract the signals in the phase P _3. Similarly the same applies to the phase P _2, since each signal is stored in digital amount, easily object can be achieved by digitally subtracting by the central processing unit CPU. Next, the role of the detection circuits D ₁ and D ₂ is to extract the frequency component of the pulse wave.
That is, the removal of the clock component (carrier). Therefore, the A / D converter can be operated in synchronization with the clock, so that the clock component is automatically removed. Furthermore, the comparison circuit Cp can also be performed digitally. Although this method can save some analog components,
Requires many memory elements. It should be noted that the present invention can be applied not only to the fingers of the human body but also to the limbs and tails of animals. (Effect of the Invention) With a single set of conventional optical systems, it is difficult to determine the diastolic blood pressure, so the average blood pressure is determined in addition to the systolic blood pressure. The optical means had to be placed near the center in order to determine the mean blood pressure more correctly. However, this results in obtaining an intermediate signal between the signals Sa 'and Sb' according to the change in the volume of the blood vessel in the present invention, and obviously the systolic blood pressure is measured higher than it actually is. Also, since the distance between the two sets of optical means is short, there is little difference in physical characteristics of blood vessels and cortex, and there is little phase difference. Further, since the same pressure is applied to both optical systems, the coincidence of the outputs at the lowest blood pressure is high in accuracy. Although more time-divisionally emitting the effect on the reduction of power consumption, and by providing a phase P ₃ which does not emit both light-emitting elements, possible to increase this time further enhance the effect. As described in detail above, the systolic blood pressure can be measured more accurately than the method in which one set of optical means is provided at the center of the pressurizing section, and the distance between the two sets of optical means is short. It is possible to measure the diastolic blood pressure with higher accuracy than the method of placing. Further, the time-division lighting has the effect of simultaneously removing extraneous light, eliminating mutual interference between two sets of optical means, and reducing power consumption.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a signal processing circuit diagram according to one embodiment of the blood pressure measuring device according to the present invention, FIG. 2 is a partially cutaway sectional view of a configuration of a detecting section of the present invention, and FIG. FIG. 4 and FIG. 5 are diagrams showing blood vessels and blood flow for determining the highest and lowest blood pressure, and FIG. 6 is a signal processing showing another embodiment of the present invention. FIG. 7 is a circuit diagram showing a partly added circuit for improving the present invention, FIG. 8 is an explanatory diagram of the operation thereof, and FIG. 9 is a signal processing circuit diagram showing another embodiment of the present invention. Ea, Eb ... light emitting element, Da, Db ... light-receiving _{element, A 1, A 2, A} 5 ... amplifiers, A _31, A ₃₂ ... differential amplifier, D _1, D ₂ ... detector, Cp ... comparator, A ... Artery, B ... Bladder, C ... Cuff, F ... Finger, S
… Pressure / decompression device, A ₄ … Variable gain amplifier, Ct… A / D converter, M… Memory, CPU… Central processing unit.

Claims (1)

(57) [Claims] A blood pressure measurement device attached to a part of a living body and performing non-invasive blood pressure measurement, wherein a pressure is applied to the part of the living body and then reduced to generate a dimensional change in a blood vessel in a diameter direction. Means, disposed on the distal side of the living body, comprising a first light-emitting unit and a first light-receiving unit, and first optical detection means for optically detecting a change in the shape of the blood vessel in the diameter direction; A second optical detecting means disposed on the heart side of the living body and comprising a second light emitting unit and a second light receiving unit, for optically detecting a change in the shape of the blood vessel in the diameter direction; A switching operation for operating the first optical detection means and the second optical detection means in a time-division manner by alternately lighting the first light-emitting section and the second light-emitting section in a state. Means for detecting a systolic blood pressure from a detection signal of the first optical detection means. Blood pressure measuring apparatus characterized by a control determining means for measuring the diastolic blood pressure respectively by comparing the detection signals of the optical detecting means and the detection signal of the second optical detection means. 2. A blood pressure measurement device attached to a part of a living body and performing non-invasive blood pressure measurement, wherein a pressure is applied to the part of the living body and then reduced to generate a dimensional change in a blood vessel in a diameter direction. Means, disposed on the distal side of the living body, comprising a first light-emitting unit and a first light-receiving unit, and first optical detection means for optically detecting a change in the shape of the blood vessel in the diameter direction; A second optical detection means disposed on the heart side of the living body and comprising a second light emitting unit and a second light receiving unit, for optically detecting a change in the shape of the blood vessel in the diameter direction; In the state, by providing a period in which the first light emitting unit and the second light emitting unit are simultaneously in a non-operation state, and by alternately lighting the first light emitting unit and the second light emitting unit, , The first optical detection means and the second optical detection means are alternately time-divisionally And switching operation means for moving, in the operating state of the first optical detector and the second optical detection means, a first detection signal obtained respectively, said first
External light removing means for removing the influence of the extraneous light based on a difference operation between the second light emitting section and the second light emitting section in a non-operating state, and the extraneous light removing means, The first optical detection means and the second optical blood pressure calculated from the detection signal of the first optical detection means from which the extraneous light has been removed and the extraneous light removed from the detection signal by the extraneous light removal means. A blood pressure measurement device comprising: a determination unit configured to determine a diastolic blood pressure based on a comparison value of a detection signal of the optical detection unit. 3. At the start of pressurization by the pressurizing / depressurizing means, the first optical detecting means and the second optical detecting means are set so that the detected value of the first optical detecting means is equal to the detected value of the second optical detecting means at a pressurizing force equal to or lower than the average diastolic blood pressure. The detection signal of the optical detection means of
3. The blood pressure measurement device according to claim 1, further comprising an adjustment unit that adjusts a gain of a detection signal of the optical detection unit.