JPH0523771B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] Although the present invention relates to a blood pressure measurement strap, the present invention is applicable not only to blood pressure but also to the pulse wave travel time over a certain distance of the brachial artery under the strap. The blood flow velocity can be measured simultaneously based on the detection of The present invention relates to a strap for measuring blood pressure and pulse wave transit time, which is useful for medical diagnosis and treatment associated with blood pressure fluctuations, and which can prevent measurement errors due to incorrect connection of the strap with a pump or a pressure gauge.

[Conventional technology]

The causes of blood pressure fluctuations are mainly thought to be changes in cardiac function and peripheral function, but it is not possible to determine non-invasively from the fluctuations in blood pressure values alone whether the fluctuations are due to fluctuations in electricity or both. I can't judge. However, if we compare the fluctuations in blood pressure values with fluctuations in blood flow velocity, which are also closely related to changes in cardiac function and peripheral function, we can investigate the cause of the fluctuations in blood pressure non-invasively. .

However, since the conventional blood pressure measurement cuff has the structure shown in Figure 4, it is only possible to measure blood pressure fluctuations, and it is not possible to measure the blood flow velocity as well as the blood flow rate by conversion. However, it was not possible to detect pulse wave transit time, which is possible, and it was necessary to wait for other testing methods to investigate the cause of blood pressure fluctuations. In other words, the conventional cuff A' for blood pressure measurement is
A large rubber pouch 3 and a medium rubber pouch 4 are connected to each other through a connecting tube 2 in a cloth pouch 1, and the large rubber pouch 3 is positioned and fixed on the central side of the brachial artery. A conduit 5 led out from one end of the inner rubber case 3 is connected to a pump 7 having an exhaust adjustment valve 6, while a conduit 8 led out from one end of the inner rubber case 4.
It has a structure in which it is connected to a pressure gauge 9, etc. and a shibari
A' is wrapped around the upper arm, the cuff A' is pressurized to a predetermined level via the pump 7, and the pressure is gradually reduced via the exhaust control valve 6, and the arterial sound is detected using an audioscope or arterial sound detection means. The systolic pressure (maximum blood pressure) and diastolic pressure (minimum blood pressure) were exclusively measured by reading the pressure value of the cuff A' pressure at that time using a pressure gauge 9 or the like. Therefore, in this structure, the pressure due to the pulse wave applied to the large rubber sac 3 and the middle rubber sac 4 when the pulse wave enters the band A' due to the pressure reduction of the band A' passes under the large rubber sac 3 and the middle rubber sac 4. The signal is discharged from the middle rubber sac 4 to the conduit 8 and detected as a pulse wave signal, and based on the detection of the arterial sound generated as the pulse wave is released from below the middle rubber sac 4 to the distal side. Blood pressure can only be measured and the cuff
It is not possible to detect the travel time of the pulse wave passing a certain distance below A'. In this case, a separate conduit is led out from the large rubber pouch 3 and the strap is tied.
Even if we try to detect the pulse wave travel time by extracting the pressure signal caused by the pulse wave when it enters below A', the pressure signal due to the pulse wave attenuates due to the large resistance due to the large volume of the large rubber 3. Since the rate is high, it is not possible to accurately extract the pressure signal due to the pulse wave at the time of entry under the cuff A', and as a result, it is difficult to detect the pulse wave travel time.

In addition, in the conventional cuff A' for measuring blood pressure, as in the pump, the pump connection conduit 5 and the pressure gauge etc. connection conduit 8 are connected to the large rubber pouch 3 and the medium rubber pouch 4 in the cuff A', respectively. Although they are connected separately, the leading ends of the strap A' to the outside are placed close to each other, so it is often the case that the conduit 5 and conduit 8 are incorrectly attached to the pump, pressure gauge, etc. As a result, there was a high possibility that blood pressure measurement would be accompanied by measurement errors due to insufficient detection of arterial sounds.

[Problem to be solved by the invention]

The present invention has been developed in view of the fact that the above-mentioned conventional blood pressure cuffs can only measure blood pressure values, and therefore other testing methods are required to investigate blood pressure fluctuations. To enable detection of pulse wave travel time, which can be calculated by converting blood flow velocity, at the same time as blood pressure measurement, and to enable investigation of the cause of blood pressure fluctuations in a non-invasive manner without requiring other testing methods. as the primary purpose, and
A second purpose is to reliably prevent measurement errors in blood pressure measurement due to incorrect attachment of connecting conduits to rubber bladders, pumps, pressure gauges, etc., which frequently occur in the conventional blood pressure measurement straps.

[Means to solve the problem]

In order to achieve the above first object, the present invention has the following features:
In addition to the conventional large rubber sac and medium rubber sac for blood pressure measurement, which are fixedly placed within the cuff from the central side of the brachial artery to the distal side, there is also a rubber sac located on the central side of the brachial artery from the large rubber sac. By providing a separate small rubber sac and extracting the pressure signal when the pulse wave enters the ligament through a guide tube led out from the small rubber sac, a certain distance of the brachial artery under the ligament is detected. The first feature is that it makes it possible to detect the pulse wave travel time for the pulse wave, and in order to achieve the second purpose, the connection that was conventionally led to the outside separately from the large rubber sac and the middle rubber sac. A second feature is that the service conduit is a single conduit, and the single conduit and the outlet tube of the small rubber lining are connected at a predetermined position. In other words, the overall structure of the strap of the present invention is that ``a small rubber bladder, a large rubber bladder, and a medium rubber bladder are fixedly arranged in that order within a cloth bladder from the central side to the distal side of the brachial artery. , the small rubber sac is separated from the large rubber sac, while the middle rubber sac is connected to the large rubber sac via a connecting tube, and one end of the small rubber sac is connected to the sac when the pulse wave enters the ligament. A single conduit is led out from one end of the inner rubber tube along the downstream side in the distal direction of the brachial artery, and the distal end of the signal guide tube is connected to the inner rubber tube of the single conduit. A pump and an arterial sound pump are connected at an appropriate distance downstream from the lead-out end of the single conduit, and have an exhaust adjustment valve further downstream from the point of connection with the signal lead-out pipe at the distal end of the single conduit. branch-connecting the detection means and the pulse wave signal detection means, respectively;
In addition, the volume ratio of the large rubber bladder, the medium rubber bladder, and the small rubber bladder is set to a predetermined value in order to meet the purpose of detecting blood pressure and pulse wave travel time.

[Effect]

The operation of the present invention with the above configuration will be explained. Wrap the cuff A around the upper arm B and operate the pump to send compressed air into each rubber sac, increasing the pressure inside the cuff to about 30 to 40 mmHg above the level where the blood flow in the brachial artery stops.
After pressurizing to a high pressure, the pressure inside the strap is gradually reduced at a predetermined pressure reduction rate using an exhaust adjustment valve.

However, when the pressure within the cuff is reduced to such an extent that the pulse wave of the brachial artery can pass under the cuff against the pressure within the cuff, the pulse wave of the brachial artery that has entered under the cuff will be affected by that pressure. First, the small rubber sac is pressed to cause a change in volume, and then, as it passes under the ligament towards the distal side of the brachial artery, it is connected to the large rubber sac via a connecting tube. During this process, the rubber sac undergoes a volume change. When the pulse wave of the brachial artery starts to enter under the ligament and presses on the small rubber sac, the compressed air inside the small rubber sac is discharged into the pulse wave signal derivation tube according to the pressure, which causes the pulse wave to go under the ligament. The pulse wave signal SP at the time of entry is sent to the pulse wave signal detection means via a single conduit connected to the pulse wave signal derivation tube, and the pulse wave signal is transmitted via the pressure inside the cuff at that time.
SP pressure is measured. The pressure signal of the pulse wave signal SP at the time of entry under the cuff has a small attenuation rate because the small rubber sac has a small volume and low resistance, and the time required for it to reach the pulse wave signal detection means is very short. On the other hand, the pulse wave that has entered the area under the ligament then presses on these rubber sacs as it passes from the large rubber sac to the underside of the middle rubber sac, and the compressed air inside the sac is released into the middle rubber sac according to the pressure. It is discharged from the body into a single conduit, and is sent to the pulse wave detection means as a pressure signal of the pulse wave signal SP' when the ligament passes. At this time, an arterial sound SK is generated by the blood discharged from the medial bladder to the peripheral side due to the pulse wave proceeding to the peripheral side, and this is sent to the arterial sound detection means via a single conduit. Therefore, along with the detection of this first generated arterial sound SK, the pressure of the pulse wave signal SP' at that time is measured by the pulse wave detection means via the pressure in the cuff, and this is calculated as the systolic pressure (maximum blood pressure). Then, the pulse wave signal SP derived from the small rubber sac when the pulse wave enters the ligament, and the pulse wave signal SP' derived from the middle sac when the pulse wave passes through the ligament, are sent to the respective pulse wave signal detection means. The arrival time varies depending on the amount of resistance caused by the difference between the volume of the small rubber sac and the volumes of the large and medium rubber sacs, so that SP precedes SP' and there is a third
As shown in the figure, the time of St is measured. This time St corresponds to the time when the pulse wave passes the distance L (shown in the first and second diagrams) from the small rubber sac to the middle rubber sac under the cuff, and each rubber sac within the cuff is Since they are fixedly arranged at predetermined positions, the distance L between the two points is
is constant and corresponds to the distance between two points on the brachial artery under the ligature. Therefore, the said time
St is the time it takes for the pulse wave to travel the distance L between two points in the brachial artery under the pressure of the cuff. Next, as the cuff pressure is gradually decreased, the amplitude of the arterial sound generated from the middle rubber bladder gradually decreases and eventually disappears, but the amplitude of the arterial sound when the amplitude suddenly decreases just before it disappears. The sound DK is detected, and the pressure of the pulse wave signal DP′ at that time is measured to measure the diastolic pressure (minimum blood pressure). At this time, the time Dt between the pressure signal DP of the pulse wave when the diastolic pressure is applied under the ligament and the pressure signal DP′ of the pulse wave when the ligament passes, and the time Dt when the pulse wave is entered under the ligament when the arterial sound has completely disappeared. A series of times such as the time Pt between the pulse wave signal Po and the pulse wave signal Po' when passing through the cuff, and the blood pressure value are measured. The detection time difference St of the pulse wave signal when the pulse wave enters the ligament and when it passes through the ligament in each phase of this blood pressure,
When cardiac and peripheral functions are normal (blood pressure regulation function is working normally), Dt and Pt gradually shorten regularly as the cuff pressure decreases, but when there is an abnormality in cardiac function. In some cases, variations appear in the regularity.

Therefore, based on the travel time of the pulse wave passing through a certain distance L between two points in the brachial artery under cuff compression detected as described above, it is converted into blood flow velocity (m/s), and the systolic pressure is calculated. By comparing blood pressure fluctuations in diastolic pressure with fluctuations in blood flow velocity in each period and between them,
It is possible to non-invasively determine whether blood pressure fluctuations are caused by fluctuations in cardiac function, peripheral function, or both.

〔Example〕

Next, an example of implementing the present invention will be shown with reference to the attached drawings, FIGS. 1 to 3. A is a binding belt, cloth bag 10
Inside, there are 3 large, medium, and small rubber bags 11, 12, 1
3 is fixedly placed by a seam surrounding its periphery. The large rubber sac 11 and the middle rubber sac 12 are connected through a small-diameter connecting tube 14, and the large rubber sac is located closer to the center of the brachial artery than the middle rubber sac.
The small rubber sac 13 is separated from the large rubber sac 11 and is placed further upstream of the large rubber sac, that is, on the central side of the brachial artery when the cuff A is used. From one side end of the small rubber sac 13, a pulse wave signal deriving tube 15, which is used at the time of entry under the cuff, is led out toward the distal side of the brachial artery, and its tip connects to the connecting tube of the middle rubber sac 12. A single conduit 16 is led out from the end opposite to 14 toward the distal side of the brachial artery by an appropriate distance from the inner rubber sac 12 to the distal side downstream of the brachial artery (in the example diagram, the ligature is (external to A). The external lead-out end of the single conduit 16 led out from the inner rubber bag 12 from the strap A connects to the pulse wave signal detection sensor 17 at the tip further downstream from the connection position with the pulse wave signal lead-out pipe 15. , an arterial sound detection sensor 18 , and a pump 20 having an exhaust adjustment valve 19 are connected by branch piping. Pulse wave signal detection sensor 17 and arterial sound detection sensor 1
8 are respectively connected to a pulse wave (pressure) measuring means, an arterial sound measuring means, and a control means such as a microcomputer for controlling these. A single conduit 16 connected to a pump 20 with an exhaust adjustment valve 19 connects to a medium rubber pouch 12, which in turn connects to a large rubber pouch 11 via a connecting pipe 14; Small rubber sac 1 separated from rubber sac 11
3 is connected to the single conduit 16 led out from the inner rubber bag 12 via the outlet pipe 15 at a position downstream of the inner rubber 12, so that the outlet pipe 15 and the single conduit 1
6 is also used for supplying and exhausting into each rubber sac, and with this piping connection configuration, the air pressure inside each rubber sac 11, 12, 13 is maintained at the same pressure, and when the pump 20 is operated, the air pressure is maintained at the same pressure. Also, the pressure inside each rubber chamber 11, 12, 13 undergoes the same pressure change. In addition, due to the arrangement of the rubber sac and the piping connection configuration, the small rubber sac 1 accompanying the pulse wave entering and passing under the cuff.
There is no possibility that the pressure change (vibration) of 3 and the pressure change (vibration) of the large rubber case 11 and the medium rubber case 12 will affect each other. And 1 of each of the above rubber
The volume ratios of 1, 12, and 13 are predetermined based on standards such as WHO, in order to meet the purpose of detecting blood pressure and pulse wave transit time. By the way, shibari A
The width of the cloth bag ₁₀ is 140 mm or more, which satisfies the WHO standard for blood pressure measurement straps.
The width of each rubber bag placed inside is 11 large rubber bags.
Based on the width _l2 of the small rubber pouch 13, the width l1 of the small rubber pouch ₁₃ and the width _l3 of the middle rubber pouch are 1/8 and 1/8 of the width l2 of the large rubber pouch ₁₁ , respectively.
It is set at around 6. Also, the width _l0 of the cloth pouch 10 of strap A varies slightly depending on whether it is for adults, children, or infants, but the ratio of the width of each rubber pouch is the same as above within that range. It is configured at a ratio of

However, as mentioned above, while performing predetermined pressurization and decompression operations on the cuff A wrapped around the upper arm, the pulse of the brachial artery that enters under the cuff A and progresses to the distal side of the blood vessel is measured in the manner shown in Figure 3. Detection of pulse wave signals SP, DP, and Po at the time when the wave starts to enter below the band A, and pulse wave signals SP', DP', and Po' when the pulse wave passes through the band A (passing the inner rubber wall 12) and no detection of arterial sounds SK, DK, systolic pressure (pressure in cuff A based on pulse wave signal SP' indication) and diastolic pressure (pressure in cuff A based on pulse wave signal SP') and diastolic pressure (pressure in cuff A based on pulse wave signal SP') In addition to measuring the pressure inside cuff A based on the indication of signal DP', pulse wave signals SP and SP', DP and DP', and P and P' are detected with time differences due to the compression resistance of cuff A. The travel time of the pulse wave traveling the distance L between the two points of the brachial artery under the cuff A is detected, and this pulse wave travel time is expressed as the blood flow velocity (m/
Measure the blood flow velocity at each time point in terms of S). Pulse wave signal emitted by vibration of small rubber bladder 13
SP, DP, Po and pulse wave signals SP', DP', which are emitted by the vibrations of the rubber pouch 12 inside the large rubber pouch 11;
Po is detected as a pressure signal by the pulse wave signal detection sensor 17, and is converted into an electrical signal to measure the pressure (blood pressure value). Also pulse wave signal
Arterial sound SK that occurs late when SP' and DP' are led out from the inner rubber sac 12 to the single conduit 16,
DK is detected by the arterial sound detection sensor 18 and converted into an electrical signal, and the arterial sound is measured.

〔Effect of the invention〕

Since the present invention is configured as described above, it solves the problems of the prior art described above and has the following effects.

First, unlike conventional methods, the large and medium rubber sacs are fixedly arranged in a predetermined order from the central side to the distal side of the brachial artery, which are connected to the brachial artery via a connecting tube within the cloth sac of the straitjacket. Separately, a small rubber sac, which is located closer to the center of the brachial artery than the larger rubber sac and is separate from the larger rubber sac, is also fixedly placed within the cloth sac, and a pulse wave signal derivation tube led out from the small rubber sac. A gas flow path was formed by connecting a single conduit led out from the middle rubber pouch at a position downstream from the middle rubber pouch, and the volume ratio of each large, medium, and small rubber pouch was set to a predetermined ratio. Therefore, it is possible to measure systolic pressure (systolic pressure) and diastolic pressure (diastolic pressure) based on the detection of arterial sounds as in the past, and it is also possible to measure the pulse wave when it enters below the ligament, which was difficult in the past. The pulse wave signal can be reliably detected, and the pulse wave signal is detected with a time difference when passing under the cuff. It is possible to detect the travel time of a pulse wave that has passed a certain distance between two points in the body, corresponding to each heartbeat from systolic pressure to diastolic pressure, and by converting this, it is possible to calculate the blood flow velocity. Measurement becomes possible. Therefore, in addition to measuring blood pressure values using a blood pressure cuff, we also take into account the mutual relationship between blood pressure fluctuations and blood flow velocity fluctuations based on repeated tests of subjects or comparisons with standard patterns. This makes it possible to determine non-invasively whether blood pressure fluctuations are caused by changes in cardiac function, peripheral function, or both, without waiting for cardiac catheterization or other testing methods, and to improve medical care associated with blood pressure fluctuations. useful for diagnosis and treatment.

Secondly, in the past, the conduit for connecting the pump and the conduit for connecting the pressure gauge were provided separately, and although the connection positions with respect to the rubber sac were different, there was no connection between the conduit and the pressure gauge. Because the connecting end of the external conduit is located close to the external conduit, there is a high possibility that incorrect attachment of the conduit for connecting the pump and pressure gauge will cause measurement errors in isopressure measurement, which may make it difficult to detect arterial sounds. It was hot. In contrast, in the present invention, the external conduit connected to each rubber tube is not divided into one for pump connection and one for pressure gauge connection, but is made into a single conduit, thereby solving the above-mentioned difficulty associated with incorrect attachment of external conduit. It is possible to ensure accuracy in blood pressure measurement and to simplify the overall structure, which is suitable for manufacturing and use.

[Brief explanation of the drawing]

FIGS. 1 to 3 show an example of the implementation of the present invention, and FIG. 1 is a plan view of the strap in a state where the strap is connected to the supply/exhaust means and the signal detection means, with main parts in cross section;
Fig. 2 is an explanatory diagram of the use of the cuff wrapped around the upper arm; Fig. 3 is a diagram explaining the principle of a detection method for detecting the travel time of a pulse wave under the cuff using the cuff;
FIG. 4 is a plan view showing a main part of a conventional cuff for measuring blood pressure in cross section. A...Bandage, 10...Cloth bag, 11...Large rubber bag, 12...Medium rubber bag, 13...Small rubber bag, 14...Connecting tube, 15...Pulse wave binding Pulse wave signal derivation tube when entering the subleucorrhea, 16...Single conduit, 17...
...Pulse wave signal detection sensor, 18...Arterial sound detection sensor, 19...Exhaust adjustment valve, 20...Pump.

Claims (1)

[Claims] 1. Fixedly place the small rubber sac, large rubber sac, and medium rubber sac in that order in the cloth sac from the central side to the distal side of the brachial artery, and separate the small sac from the large sac. On the other hand, the medium rubber sac is connected to the large rubber sac via a connecting tube, and from one end of the small rubber sac, a signal output tube when the pulse wave enters the ligament is connected to one side of the middle rubber sac. A single conduit is led out from the side end along the downstream side in the distal direction of the brachial artery, and the tip of the signal lead-out tube is placed an appropriate distance from the end of the single conduit from the inner rubber sac to the distal end side. A pump, an arterial sound detecting means, and a pulse wave signal detecting means each connected to a downstream position and having an exhaust adjustment valve at a distal end of the single conduit further downstream from the connecting position with the signal deriving pipe. Blood pressure and pulse wave movement, characterized in that the volume ratio of the large rubber bladder, the medium rubber bladder, and the small rubber bladder is set to a predetermined value in order to have a branch connection and to meet the purpose of detecting blood pressure and pulse wave transit time. A strap for measuring time.