blood pressure monitor

Abstract

To provide a non-invasive blood pressure monitor capable of measuring blood pressure when a cuff is pressurized and extending the life of a pressure pump. [Solution] A non-invasive blood pressure monitor 1 for measuring blood pressure includes a cuff 3 wrapped around a measurement site 2, a pressure pump 7 for supplying air to the cuff 3, and an air tank 8 and air filters 10, 11 arranged in the air supply path from the pressure pump 7 to the cuff 3. An air chamber 23 is formed inside the air tank 8 and is arranged closer to the pressure pump 7 than all of the air filters 10, 11 in the air supply path from the pressure pump 7 to the cuff 3, and air flowing from the pressure pump 7 into the air tank 8 flows into the air chamber 23.

Description

[Technical Field]

[0001] The present invention relates to a non-invasive blood pressure monitor. [Background technology]

[0002] Conventionally, a non-invasive electronic blood pressure monitor including a cuff and a pressure pump for supplying air to the cuff has been known (see, for example, Patent Document 1). The electronic blood pressure monitor disclosed in Patent Document 1 includes an air flow control means disposed between the cuff and the pressure pump. The air flow control means includes an air tank and fine tubes disposed on both sides of the air tank. The air inlet of the air tank is connected to the pressure pump via the fine tube and an air tube, and the air outlet of the air tank is connected to the cuff via the fine tube and an air tube. In the electronic blood pressure monitor disclosed in Patent Document 1, due to the action of the air flow control means, fluctuations in the flow rate of the pressure pump do not appear as fluctuations in the cuff pressure, and air pressure vibrations due to pressure pump pulsation are not transmitted to the air pressure in the cuff. Therefore, this electronic blood pressure monitor is capable of measuring blood pressure when the cuff is inflated. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Unexamined Patent Publication No. 62-192139 Summary of the Invention [Problem to be solved by the invention]

[0004] As described above, the electronic blood pressure monitor described in Patent Document 1 is capable of measuring blood pressure while inflating the cuff. However, in this electronic blood pressure monitor, the fine tubes arranged between the air inlet of the air tank and the pressure pump tend to place a large load on the pressure pump when inflating the cuff. As a result, this electronic blood pressure monitor may have a short lifespan for the pressure pump. Furthermore, the electronic blood pressure monitor described in Patent Document 1 is unable to control the cuff inflation speed.

[0005] Therefore, a first object of the present invention is to provide a non-invasive blood pressure monitor that can measure blood pressure while inflating the cuff and can extend the life of the pressure pump.A second object of the present invention is to provide a non-invasive blood pressure monitor that can control the cuff inflation speed. [Means for solving the problem]

[0006] In order to achieve the first object, the blood pressure monitor of the present invention is a non-invasive blood pressure monitor for measuring blood pressure, comprising: a cuff to be wrapped around a measurement site; a pressure pump for supplying air to the cuff; and an air tank and an air filter disposed in an air supply path from the pressure pump to the cuff, wherein at least one air filter is disposed inside the air tank, and an air chamber is formed which is disposed closer to the pressure pump than all the air filters in the air supply path from the pressure pump to the cuff, and the air filter disposed inside the air tank is composed of two silencers and a silencer fixing plate to which the two silencers are fixed, The silencer is fixed to the silencer fixing plate from both sides of the silencer fixing plate, The air flowing from the pressure pump into the air tank flows into the air chamber.

[0007] In the blood pressure monitor of the present invention, an air tank and an air filter are disposed in the air supply path from the pressure pump to the cuff. Therefore, in the present invention, fluctuations in the flow rate of air supplied from the pressure pump to the cuff are unlikely to manifest as fluctuations in the pressure inside the cuff. Therefore, in the present invention, blood pressure can be measured while the cuff is inflated. Furthermore, in the present invention, air flowing from the pressure pump into the air tank flows into an air chamber located closer to the pressure pump than any other air filters in the air supply path from the pressure pump to the cuff, without passing through an air filter. Therefore, in the present invention, a large load is unlikely to be placed on the pressure pump when inflating the cuff via the air tank. Therefore, in the present invention, blood pressure can be measured while the cuff is inflated, while the life of the pressure pump can be extended.

[0008] In order to achieve the second object, the present invention provides a non-invasive blood pressure monitor for measuring blood pressure, comprising: a cuff to be wrapped around a measurement site; a pressure pump for supplying air to the cuff; an air tank and an air filter disposed in an air supply path from the pressure pump to the cuff; a first air pressure sensor for detecting the air pressure inside the air tank; a second air pressure sensor for detecting the air pressure inside the cuff; and a blood pressure monitor control unit having a pump control circuit for controlling the pressure pump, wherein the air tank is provided with: At least one air filter is disposed; An air chamber is formed in the air supply path from the pressure pump to the cuff, which is located closer to the pressure pump than at least one air filter, a first air pressure sensor detects the air pressure in the air chamber, and a blood pressure monitor control unit controls the pressure pump based on the detection result of the first air pressure sensor.

[0009] The blood pressure monitor of the present invention includes a first air pressure sensor for detecting the air pressure inside an air tank disposed in the air supply path from the pressure pump to the cuff, and the pressure monitor control unit controls the pressure pump based on the detection result of the first air pressure sensor. Therefore, the present invention makes it possible to control the inflation speed of the cuff. Furthermore, the first air pressure sensor detects the air pressure in an air chamber disposed closer to the pressure pump than at least one air filter in the air supply path from the pressure pump to the cuff. Due to the action of the air filter, the detection result of the first air pressure sensor is less susceptible to the influence of the pulse wave at the measurement site. Therefore, the present invention makes it possible to accurately control the inflation speed of the cuff based on the detection result of the first air pressure sensor. [Effects of the Invention]

[0010] As described above, the blood pressure monitor of the present invention can measure blood pressure while inflating the cuff, and can extend the life of the pressure pump. Furthermore, the blood pressure monitor of the present invention can control the inflation speed of the cuff. [Brief explanation of the drawings]

[0011] [Figure 1]1 is a schematic diagram for explaining a configuration of a sphygmomanometer according to an embodiment of the present invention. [Figure 2] FIG. 2 is a block diagram for explaining the configuration of the sphygmomanometer shown in FIG. [Figure 3] FIG. 10 is a schematic diagram for explaining the configuration of a sphygmomanometer according to another embodiment of the present invention. [Figure 4] FIG. 4 is a block diagram for explaining the configuration of the sphygmomanometer shown in FIG. 3. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0013] (Blood pressure monitor configuration) Fig. 1 is a schematic diagram for explaining the configuration of a sphygmomanometer 1 according to an embodiment of the present invention, and Fig. 2 is a block diagram for explaining the configuration of the sphygmomanometer 1 shown in Fig. 1.

[0014] The sphygmomanometer 1 of this embodiment is a non-invasive sphygmomanometer for measuring the blood pressure of humans or laboratory animals, etc. The sphygmomanometer 1 includes a cuff 3 that is wrapped around a measurement target 2, such as the subject's arm, to compress an artery, a Korotkoff sound microphone 4 (hereinafter referred to as "microphone 4") attached to the cuff 3, and a sphygmomanometer main body 5 to which the cuff 3 is connected. The sphygmomanometer main body 5 includes a pressure pump 7 for supplying air to the cuff 3, and an air tank 8 and air filters 10 and 11 arranged in the air supply path from the pressure pump 7 to the cuff 3. The sphygmomanometer main body 5 of this embodiment includes two air filters 10 and 11.

[0015] Furthermore, sphygmomanometer main body 5 includes air pressure sensor 12 for detecting the air pressure inside air tank 8, air pressure sensor 13 for detecting the air pressure (internal pressure) inside cuff 3, intermediate exhaust valve 14 and constant speed exhaust valve 15 for discharging air inside air tank 8, total exhaust valve 16 for discharging air inside cuff 3, and sphygmomanometer control unit 17 for controlling sphygmomanometer 1. In this embodiment, air pressure sensor 12 is a first air pressure sensor, and air pressure sensor 13 is a second air pressure sensor.

[0016] The air tank 8 is formed, for example, in a cylindrical (pipe) shape with both ends closed. The air tank 8 is formed, for example, from polyvinyl chloride. For example, the total length of the air tank 8 is about 150 mm, the outer diameter of the air tank 8 is about 38 mm, and the wall thickness of the air tank 8 is about 3.5 mm.

[0017] The air filter 10 is composed of two silencers 21 and a silencer fixing plate 22 to which the two silencers 21 are fixed. Like the air filter 10, the air filter 11 is composed of two silencers 21 and a silencer fixing plate 22. The air filters 10 and 11 function as air resistors. The air filters 10 and 11 are disposed inside the air tank 8. The silencer fixing plate 22 is formed in a circular plate shape and is fixed to the inner circumferential surface of the air tank 8. The silencers 21 are fixed to the silencer fixing plate 22 from both sides of the silencer fixing plate 22.

[0018] The interior of air tank 8 is partitioned by air filters 10 and 11, and air chamber 23, air chamber 24, and connecting chamber 25 are formed inside air tank 8. In this embodiment, the interior of air tank 8 is composed of air chamber 23, air chamber 24, and connecting chamber 25. Air chamber 23 is formed between one end of air tank 8 and air filter 10. Air chamber 24 is formed between air filter 10 and air filter 11. Connecting chamber 25 is formed between the other end of air tank 8 and air filter 11. Connecting chamber 25 is narrower than air chambers 23 and 24.

[0019] The air chamber 23 is connected to the pressure pump 7 via an air tube 26, one end of which is attached to the air inlet of the air tank 8, and air flowing from the pressure pump 7 into the air tank 8 flows into the air chamber 23. The cuff 3 is connected to the connection chamber 25 via an air tube 27, one end of which is connected to the air outlet of the air tank 8, and air flowing out of the air tank 8 flows out from the connection chamber 25. The air inlet and outlet are, for example, pipes made of an aluminum alloy. Thus, within the air tank 8, there are formed, in the air supply path from the pressure pump 7 to the cuff 3, an air chamber 23 that is located closer to the pressure pump 7 than all of the air filters 10, 11, and an air chamber 24 that is located closer to the pressure pump 7 than one air filter 11.

[0020] Air pressure sensor 12 is connected to air chamber 24 via air tube 28, one end of which is attached to the air inlet / outlet port of air tank 8. The air inlet / outlet port is, for example, a pipe made of an aluminum alloy. Air pressure sensor 12 serves to detect the air pressure in air chamber 24. That is, air pressure sensor 12 serves to detect the pressure of the air in air tank 8 that has passed through air filter 10. Air pressure sensor 13 is connected to cuff 3 and connection chamber 25 via air tube 27 and the like. As described above, air pressure sensor 13 serves to detect the internal pressure of cuff 3. In this embodiment, the detection result of air pressure sensor 13 is used to measure blood pressure, and the detection result of air pressure sensor 12 is not used to measure blood pressure.

[0021] The intermediate exhaust valve 14 and the constant speed exhaust valve 15 are connected to the air chamber 24 via an air tube 28. The full exhaust valve 16 is connected to the cuff 3 and the connection chamber 25 via an air tube 27 and the like. The intermediate exhaust valve 14 and the full exhaust valve 16 are on-off valves. As will be described later, the sphygmomanometer 1 is capable of measuring blood pressure when the cuff 3 is depressurized. The intermediate exhaust valve 14 and the constant speed exhaust valve 15 are used when measuring blood pressure when the cuff 3 is depressurized. The full exhaust valve 16 is used to remove air from inside the cuff 3 after blood pressure measurement has been completed.

[0022] The sphygmomanometer control unit 17 includes a pump control circuit 31 that controls the pressure pump 7, an amplifier circuit 32 to which the output signal of the air pressure sensor 12 is input, a pressure wave discrimination circuit 33 to which the output signal of the air pressure sensor 13 is input, an amplifier circuit 34 connected to the total exhaust valve 16, an amplifier circuit 35 to which the output signal of the microphone 4 is input, a setting display unit 36 ​​for performing various settings and displays, and a CPU 37 to which these components are electrically connected.

[0023] The sphygmomanometer control unit 17 controls the pressure pump 7 based on the detection result of the air pressure sensor 12. Specifically, the sphygmomanometer control unit 17 controls the pressure pump 7 based on the detection result of the air pressure sensor 12 when inflating the cuff. For example, the sphygmomanometer control unit 17 controls the pressure pump 7 so that the pressure in the cuff 3 increases at a constant rate regardless of the size of the cuff 3. Furthermore, for example, after starting blood pressure measurement, the sphygmomanometer control unit 17 rapidly inflates the pressure in the cuff 3 until the cuff 3 lightly contacts the measurement target 2 (for example, until the pressure in the cuff 3 reaches about 20 to 30 mmHg), and thereafter controls the pressure pump 7 so that the pressure in the cuff 3 increases at a constant rate that is slower than that during rapid inflation.

[0024] Standard inflation gradient data for increasing the pressure in the cuff 3 at a constant rate is stored in advance in the sphygmomanometer control unit 17. Based on the detection result of the air pressure sensor 12 and the standard inflation gradient data, the sphygmomanometer control unit 17 controls the inflation pump 7 so that the pressure in the cuff 3 increases at a constant rate. The inflation rate of the cuff 3 is usually set to about 2 to 5 mmHg / sec, although it depends on the heart rate of the subject and the experimental animal.

[0025] Sphygmomanometer 1 is capable of measuring blood pressure when cuff 3 is inflated. Sphygmomanometer 1 is also capable of measuring blood pressure when cuff 3 is deflated. When measuring blood pressure when cuff 3 is inflated, air is supplied into cuff 3 so that the pressure in cuff 3 increases at a constant rate. When measuring blood pressure when cuff 3 is deflated, after the pressure in cuff 3 has been increased to a predetermined pressure, intermediate exhaust valve 14 is opened and air is discharged from air tank 8 at a constant rate.

[0026] When measuring blood pressure, a pressure fluctuation signal based on the pressure in the cuff 3 and the pulse wave superimposed thereon is output from the air pressure sensor 13 as a blood pressure detection signal. The pressure wave discrimination circuit 33 amplifies the blood pressure detection signal output from the air pressure sensor 13 and discriminates the amplified blood pressure detection signal into a pressure signal and a pulse wave signal. The CPU 37 determines the blood pressure based on the pulse wave signal input from the pressure wave discrimination circuit 33 and displays the determined blood pressure on a predetermined display unit. The pressure signal output from the pressure wave discrimination circuit 33 is a pressure signal corresponding to a pressure in which the influence of the pulse wave of the measurement target 2 has been reduced (i.e., a pressure close to the actual pressure of the cuff 3).

[0027] Furthermore, when measuring blood pressure, Korotkoff sounds (blood flow sounds, hereinafter referred to as "K sounds") output from microphone 4 are used. Specifically, when measuring blood pressure while inflating cuff 3, the blood pressure when the K sounds start to appear after inflation begins is taken as the diastolic blood pressure, and the blood pressure when the K sounds stop thereafter is taken as the systolic blood pressure. When measuring blood pressure while deflating cuff 3, the blood pressure when the K sounds start to appear after deflating begins is taken as the diastolic blood pressure, and the blood pressure when the K sounds stop thereafter is taken as the diastolic blood pressure.

[0028] (Main effect of this form) As described above, in this embodiment, air tank 8 and air filters 10, 11 are disposed in the air supply path from pressurization pump 7 to cuff 3. Therefore, in this embodiment, fluctuations in the flow rate of air (or fluctuations in air pressure) supplied from pressurization pump 7 to cuff 3 are attenuated by air tank 8 and air filters 10, 11. Therefore, in this embodiment, fluctuations in the flow rate of air supplied from pressurization pump 7 to cuff 3 are less likely to appear as fluctuations in the pressure inside cuff 3, and as a result, it becomes possible to measure blood pressure when cuff 3 is inflated.

[0029] In this embodiment, the air flowing from the pressure pump 7 into the air tank 8 flows into the air chamber 23, which is located closer to the pressure pump 7 than all the air filters 10, 11 in the air supply path from the pressure pump 7 to the cuff 3, without passing through the air filters 10, 11. Therefore, in this embodiment, a large load is less likely to be placed on the pressure pump 7 when the cuff 3 is pressurized via the air tank 8. Therefore, in this embodiment, even though it is possible to measure blood pressure when the cuff 3 is inflated, it is possible to extend the life of the pressure pump 7.

[0030] In this embodiment, sphygmomanometer 1 includes air pressure sensor 12 for detecting the air pressure inside air tank 8 arranged in the air supply path from pressure pump 7 to cuff 3, and sphygmomanometer control unit 17 controls pressure pump 7 based on the detection result of air pressure sensor 12. Therefore, in this embodiment, it is possible to control the inflation speed of cuff 3.

[0031] In this embodiment, air pressure sensor 12 detects the air pressure in air chamber 24, which is located closer to pressure pump 7 than air filter 11 in the air supply path from pressure pump 7 to cuff 3. Therefore, due to the action of air filter 11, the detection result of air pressure sensor 12 is less affected by the pulse wave of measurement subject 2. Also, in this embodiment, air pressure sensor 12 detects the air pressure in air chamber 24 formed between air filters 10 and 11. Therefore, due to the action of air chamber 23 and air filter 10, the detection result of air pressure sensor 12 is less affected by fluctuations in the flow rate of air supplied from pressure pump 7. Therefore, in this embodiment, it is possible to accurately control the inflation speed of cuff 3 based on the detection result of air pressure sensor 12.

[0032] (Example of changing a blood pressure monitor) Fig. 3 is a schematic diagram for illustrating the configuration of a sphygmomanometer 1 according to another embodiment of the present invention, and Fig. 4 is a block diagram for illustrating the configuration of the sphygmomanometer 1 shown in Fig. 3.

[0033] In the above-described embodiment, as shown in Figures 3 and 4, sphygmomanometer main body 5 does not need to include air pressure sensor 12. In a modified example shown in Figures 3 and 4, sphygmomanometer main body 5 does not include air filter 10, and the interior of air tank 8 is configured from one air chamber 40 and connecting chamber 25. In this modified example, intermediate exhaust valve 14 and constant speed exhaust valve 15 are connected to air chamber 40 via air tube 27.

[0034] In this modified example, the pressure signal output from the pressure wave discrimination circuit 33 is input to the pump control circuit 31. The sphygmomanometer control unit 17 controls the pressure pump 7 when inflating the cuff 3 based on the pressure signal output from the pressure wave discrimination circuit 33. In this modified example, the pressure pump 7 is controlled based on the pressure signal in which the influence of the pulse wave of the measurement target 2 has been reduced, so that the inflation speed of the cuff 3 can be controlled with high accuracy.

[0035] (Other embodiments) In the above-described embodiment, the sphygmomanometer 1 may not include the microphone 4. In this case, when measuring blood pressure while inflating the cuff 3, it is difficult to detect the diastolic blood pressure from the pulse wave signal while the cuff 3 is inflated. However, as the cuff 3 is further inflated, the pulse wave signal increases, and its maximum point represents the mean blood pressure. The systolic blood pressure is then detected. The diastolic blood pressure is calculated from the systolic blood pressure and the mean blood pressure.

[0036] In the above-described embodiment, air filter 11 may be disposed outside air tank 8, and connecting chamber 25 may not be formed inside air tank 8. In these cases, for example, one end of air tube 27 is connected to air filter 11. Also, in the above-described embodiment, three or more air filters may be disposed inside air tank 8, and three or more air chambers may be formed inside air tank 8.

[0037] In the above-described embodiment, sphygmomanometer main body 5 may not include air filter 10. In this case, as shown in FIG. 3, the interior of air tank 8 is configured with one air chamber 40 and connection chamber 25. In this case, air pressure sensor 12 serves to detect the air pressure in air chamber 40. In the modified example shown in FIGS. 3 and 4, sphygmomanometer main body 5 may include air filter 10.

[0038] In the above-described embodiment, the air chamber 23 does not have to be formed inside the air tank 8. In this case, for example, one end of the air tube 26 is connected to the air filter 10. Also, in the above-described embodiment, an air filter may be arranged in the air supply path from the pressure pump 7 to the air tank 8. In this case, for example, the air filter 10 does not have to be arranged inside the air tank 8.

[0039] In the above-described embodiment, blood pressure may be measured by the sphygmomanometer 1 only when the cuff 3 is inflated. When measuring blood pressure while the cuff 3 is deflated, it is usually necessary to first rapidly inflate the pressure in the cuff 3 to a constant pressure of about 150 mmHg, which requires a large inflation pump 7. However, when blood pressure is measured only when the cuff 3 is inflated, rapid inflation is not necessary, which makes it possible to downsize the inflation pump 7. However, if the cuff 3 is large, the inflation speed of the cuff 3 may drop dramatically when inflated to nearly 300 mmHg, so it is necessary to select an inflation pump 7 that is suitable for the cuff 3. [Explanation of symbols]

[0040] 1 blood pressure monitor 2 Part to be measured 3 Cuff 7 Pressure Pump 8 Air Tank 10, 11 Air filter 12 Air pressure sensor (first air pressure sensor) 13 Air pressure sensor (second air pressure sensor) 17 Sphygmomanometer control unit 23 Air Chamber 24 air chambers 31 Pump control circuit 40 air chambers

Claims

1. In a non-invasive sphygmomanometer for measuring blood pressure, a cuff to be wrapped around a measurement site; a pressure pump for supplying air to the cuff; and an air tank and an air filter disposed in a supply path of air from the pressure pump to the cuff; At least one air filter is disposed inside the air tank, and an air chamber is formed that is disposed closer to the pressure pump than all of the air filters in a path of air supply from the pressure pump to the cuff, the air filter disposed inside the air tank is composed of two silencers and a silencer fixing plate to which the two silencers are fixed, The muffler is fixed to the muffler fixing plate from both sides of the muffler fixing plate, The blood pressure monitor according to claim 1, wherein the air flowing from the pressure pump into the air tank flows into the air chamber.

2. In a non-invasive sphygmomanometer for measuring blood pressure, a cuff to be wrapped around a measurement site; a pressure pump for supplying air to the cuff; an air tank and an air filter disposed in a supply path of air from the pressure pump to the cuff; a first air pressure sensor for detecting the air pressure inside the air tank; a second air pressure sensor for detecting the air pressure inside the cuff; and a blood pressure monitor control unit having a pump control circuit for controlling the pressure pump; At least one air filter is disposed inside the air tank, and an air chamber is formed that is disposed closer to the pressure pump than the at least one air filter in a supply path of air from the pressure pump to the cuff, the first air pressure sensor detects the air pressure in the air chamber; The blood pressure monitor control unit controls the pressure pump based on a detection result of the first air pressure sensor.

Images