A non-invasive blood pressure measurement system based on rat tail

Abstract

This invention discloses a non-invasive blood pressure measurement system for rat tails, including a measuring host and a detection component. The detection component includes a first restraint and a second restraint, arranged sequentially along a first direction. The first restraint is used to restrain the rat's body, and the second restraint is used to restrain the rat's tail. A photoelectric sensor is also disposed next to the second restraint, and the photoelectric sensor is electrically connected to the measuring host and transmits data. Thus, the subject can be fixed by the first and second restraints using infrared detection, thereby achieving non-invasive blood pressure measurement of the rat tail. Compared to invasive detection methods, this results in more stable emotions in the mice, reducing stress response and ensuring relatively stable blood pressure and heart rate, leading to more accurate measurement results.

Description

Technical Field

[0001] This utility model relates to the field of experimental measurement technology, and in particular to a non-invasive blood pressure measurement system for rat tails. Background Technology

[0002] In existing technologies, tail blood pressure measurement in rats requires an invasive procedure. The rats must be restrained before the measurement is performed through an incision in their tails, which induces stress in the animals. This intense stress response activates the sympathetic nervous system, leading to a series of problems such as increased heart rate, elevated blood pressure, and abnormal hormone secretion.

[0003] The physiological responses caused by the aforementioned stress can severely affect the blood pressure measurement results in the rat tail, leading to inaccurate test results. Utility Model Content

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a non-invasive blood pressure measurement system for rat tails, which can reduce the stress level of laboratory rats and thus improve the accuracy of rat tail blood pressure measurement.

[0005] The objective of this utility model is achieved through the following technical solution: A non-invasive blood pressure measurement system for rat tail includes a measurement host and a detection component. The detection component includes a first fixator and a second fixator, which are arranged sequentially along a first direction. The first fixator is used to fix the rat's body, and the second fixator is used to fix the rat's tail. A photoelectric sensor is also disposed next to the second fixator, and the photoelectric sensor is electrically connected to the measurement host and transmits data.

[0006] The beneficial effects of this invention are as follows: The subject can be fixed using infrared detection via a first and second restraint device, thus achieving non-invasive tail blood pressure measurement in mice. Compared to invasive methods, this results in more stable emotions in the mice, reducing stress response and ensuring relatively stable blood pressure and heart rate, leading to more accurate measurement results.

[0007] Preferably, the detection assembly further includes a heating chamber, which is placed over the first fixture, and the second fixture and the photoelectric sensor are located outside the covered area of ​​the heating chamber.

[0008] Preferably, the heating chamber has an open side in the first direction, and a connection socket is provided on the open side for connecting a photoelectric sensor; a cable is provided on the other side of the heating chamber in the first direction for connecting to the measuring host, and the photoelectric sensor uses the heating chamber as an intermediary to transmit data and draw power from the measuring host.

[0009] Preferably, the first fixture includes a cage body and a head cover, and the first fixture is a mechanical component.

[0010] Preferably, the cage body is a hollow cylindrical shape, and at least a portion of the periphery of the cage body has through holes.

[0011] Preferably, the detection component further includes a tray, the width of which is less than or equal to the width inside the heating chamber, and the tray defines a first placement area and a second placement area arranged along a first direction, the first placement area being used to set the first fixture, and the second placement area being used to set the second fixture.

[0012] Preferably, the tray is a metal plate.

[0013] Preferably, the photoelectric sensor includes a built-in air pump, an air bladder, an infrared pair, and a heating tube. The air pump is used to inflate the air bladder, the air bladder is used to compress the rat's tail, the infrared pair is used to test the rat's tail blood pressure, and the heating tube is used to be fitted onto the rat's tail and heat the tail.

[0014] Preferably, it also includes a PC, on which software is installed, and the PC and the measuring host communicate via a USB cable for data exchange, and the software processes the acquired data. Attached Figure Description

[0015] Figure 1 This is a simplified schematic diagram of a rat tail non-invasive blood pressure measurement system according to an embodiment of this application; Figure 2 This is a simplified schematic diagram of a measurement host according to an embodiment of this application; Figure 3 This is a simplified schematic diagram of a rat tail non-invasive blood pressure measurement system according to an embodiment of this application; Figure 4 This is a simplified schematic diagram of the heating chamber according to an embodiment of this application; Figure 5 This is a simplified schematic diagram of the heating chamber from another angle according to an embodiment of this application; Figure 6 A simplified schematic diagram of the first and second fixators according to embodiments of this application; Figure 7 This is a schematic diagram of the detection component structure according to an embodiment of this application; Figure 8 This is a simplified schematic diagram of a photoelectric sensor according to an embodiment of this application;

[0016] In the diagram: 100-Measuring host, 110-Signal channel, 120-USB socket, 130-Power socket; 200-Detection component; 210-First fixture, 211-Cage body, 212-Head cover; 220-Second fixture, 230-Photoelectric sensor, 211-Infrared photocell, 212-Air pump, 213-Airbag, 214-Heating tube; 240-Heating chamber, 241-PTC semiconductor device, 242-Connecting socket, 243-Cable, 245-Male snap fastener, 246-Female snap fastener; 250-Tray; 300-PC. Detailed Implementation

[0017] The technical solution of this utility model will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0018] See Figures 1-8 This utility model provides a technical solution: A non-invasive blood pressure measurement system based on rat tail includes a measurement host 100 and a detection component 200.

[0019] Measurement host 100, please refer to Figures 1-3 As shown in the diagram, the dashed lines represent transmitted data, the thin solid lines represent transmitted DC power and data, and the thick solid lines represent transmitted AC power. The measurement host 100 has a built-in signal acquisition circuit and is equipped with a channel socket 110. In different examples, the channel socket 110 can include three structures: single-channel, three-channel, and eight-channel.

[0020] In some examples, such as Figure 1 and Figure 2 As shown, single-channel and triple-channel versions can share a single housing and are powered by an external power adapter. They are compact and portable. The front panel features a power switch and channel socket 110, which can be configured to accommodate one or three sockets. The rear panel has a USB socket 120 and a DC power socket 130.

[0021] In one example, such as Figure 1 and Figure 3 As shown, the measurement host 100 includes eight channels, which can be used for comparative experiments with multiple mice. Due to the large number of channels, the heating power is high, therefore AC power can be used, and the chassis has a built-in switching power supply. The front panel has a power switch and eight-channel sockets 110, while the rear panel has a USB socket 120 and a three-in-one power socket 130. Correspondingly, as... Figure 3 As shown, one measurement host 100 can connect to multiple detection components 200.

[0022] The detection component 200 includes a first fixture 210 and a second fixture 220, which are arranged sequentially along a first direction. The first fixture 210 is used to fix the mouse body, and the second fixture 220 is used to fix the mouse tail. A photoelectric sensor 230 is also provided next to the second fixture 220. The photoelectric sensor 230 is electrically connected to the measuring host 100 and transmits data.

[0023] In this embodiment, the first direction is used to clearly define the positional relationship between the first restraint 210 and the second restraint 220, and does not refer to a specific direction. The first restraint 210 fixes the mouse body at the front, while the second restraint 220 fixes the mouse tail at the rear. In order to obtain the mouse tail blood pressure measurement result, the photoelectric sensor 230 set around the second restraint 220 is an infrared sensor, including at least an infrared pair 211, which can realize the photovolume method to measure the mouse tail blood pressure.

[0024] In detail, because hemoglobin in the blood has specific light absorption characteristics, the amount of light absorbed and reflected changes accordingly when the blood volume in the rat's tail vessels changes. An infrared pair 211 emits light onto the rat's tail and receives the transmitted or reflected light, converting it into an electrical signal. When the heart contracts, blood flow increases, and vasodilation leads to enhanced light absorption and a weakened signal reception; the opposite occurs when the heart relaxes. This periodic change forms a pulse wave signal, reflecting the dynamics of vascular volume.

[0025] For example, the infrared pair 211 includes an infrared emitting tube and an infrared receiving tube. The infrared emitting tube emits infrared light of a specific wavelength, which is absorbed by substances such as hemoglobin in the blood when it passes through the skin, tissues, and blood vessels. Because the blood volume in arteries changes periodically with the contraction and relaxation of the heart, during systole, arterial blood pressure increases, blood volume increases, and the absorption of infrared light increases; during diastole, blood pressure decreases, blood volume decreases, and the absorption of infrared light decreases. Thus, the intensity of the infrared light received by the infrared receiving tube changes periodically with the pulse, forming a photoplethysmography (PPG) wave signal synchronized with the pulse. The propagation speed and waveform characteristics of the pulse wave are correlated with blood pressure. Generally, when blood pressure rises, the propagation speed of the pulse wave increases, and the rising and falling limbs of the waveform also change accordingly. By analyzing the acquired pulse wave signals, characteristic parameters such as pulse wave amplitude, period, rise time, and fall time are extracted. Then, using the established mathematical model or empirical formula of pulse wave characteristics and blood pressure, the blood pressure value can be calculated. Finally, the measured data is transmitted to the measurement host 100, which calculates and displays the results.

[0026] It is understood that, in this embodiment of the application, the subject to be tested can be fixed by infrared detection using the first restraint 210 and the second restraint 220, thereby achieving non-invasive measurement of rat tail blood pressure. Compared to invasive detection methods, the experimental mice are more emotionally stable, reducing stress response and ensuring that the blood pressure and heart rate of the experimental mice are basically stable, resulting in more accurate measurement results. In some embodiments, to ensure measurement effectiveness, the detection component 200 further includes a heating chamber 240, which is placed over the first restraint 210, while the second restraint 220 and the photoelectric sensor 230 are located outside the covered area of ​​the heating chamber 240. (Reference) Figure 4 and Figure 5 As shown, the inner wall of the heating chamber 240 is a U-shaped metal inner plate 241, which is wrapped with a heating pad or a PTC semiconductor device for heating. The outer layer is a plastic shell 248. The interlayer between the inner and outer walls provides installation space for the heating device 249, while also using air barrier to insulate and reduce heat loss, thereby improving heating efficiency. A removable cover 247 is also provided on top of the heating chamber 240 for easy access to the first restraint device 210 for restraining the mouse. The device is made of semi-transparent brown PMMA, allowing observation of the mouse's physical condition while preventing external interference.

[0027] In this way, heating the mouse's body on the first restraint 210 via the heating chamber 240 soothes the mouse and avoids heating the tail and photoelectric sensor 230, thus preventing the infrared radiation from the heater from affecting the detection area. Furthermore, placing both the mouse's body and tail in the heating chamber is problematic because the caudal artery is located in the gap between the two tail bones directly below the tail. Measurements require adjusting the tail position using blood pressure waveforms, necessitating opening the heating chamber for each adjustment, resulting in heat loss. This temperature fluctuation can trigger a stress response in the animal, making blood pressure and pulse unstable, cumbersome, and inefficient. The large size of the heating chamber further reduces heating efficiency. In this embodiment, the mouse tail is restrained separately, thus avoiding these problems.

[0028] In some examples, such as Figure 5 As shown, the heating chamber 240 has a connection socket 242 on its open side along its length for connecting the sensor; a cable 243 is provided on the back for connecting to the measuring host 100. Male buckles 245 and female buckles 246 are provided on both sides respectively. The male buckles 245 and female buckles 246 are spliced ​​together for combining multiple heating chambers 240. In some examples, the magnetic attraction principle can also be used to combine multiple heating chambers 240 together to achieve simultaneous measurement of multiple experimental mice.

[0029] In the above example, continue to refer to Figure 1 and Figure 3As shown, the system also includes a PC300 (personal computer), on which system software is installed. The measurement host 100 has a built-in signal acquisition circuit. The PC300 and the measurement host 100 exchange data via a USB cable, and the software processes the acquired data. Of course, this embodiment only uses a PC300 as an example; other types of computing devices can be used in different examples.

[0030] The heating chamber 240 of the detection component 200 transmits data to the measurement host 100 via an attached cable 243 and draws power from the measurement host 100. The multi-channel measurement host 100 can connect to multiple heating chambers 240, which can be mechanically assembled into a single unit. The photoelectric sensor 230 connects to the heating chamber 240 via the attached cable 243, using the heating chamber 240 as an intermediary for data transmission and power draw from the measurement host 100. This avoids excessive cable connections and prevents messy cable arrangement. Furthermore, directly connecting the photoelectric sensor to the host would result in a larger host unit.

[0031] Next, we will illustrate this with a specific example.

[0032] refer to Figure 6 and Figure 7 As shown, Figure 6 The simplified diagram shows that the first fixture 210 includes a cage body 211 and a head cover 212. The whole unit does not contain electrical components and can be washed with water, so there is no need to worry about contamination by rat excrement.

[0033] Further reference Figure 7 As shown, the cage body 211 is a hollow cylindrical shape with through holes in at least a portion of its circumference to ensure ventilation and heat exchange between the cylinder and the heating chamber 240. The second restraint 220 consists of a head cover 212 for clamping the mouse's head and a tail clip for clamping the tail, both hollow cylindrical in shape. The outer diameter matches the inner diameter of the cylinder, and the inner diameters are adapted to the size of the mouse's head and tail, respectively. To facilitate observation of the mouse's physical activity and to prevent the metal from causing the mouse to overheat and die, the cage body 211 is made of transparent PMMA material. Since mice prefer darkness, the head cover 212 is made of black PMMA material to help keep the mouse quiet.

[0034] In some examples, the detection component 200 also includes a tray 250, such as Figure 7The first fixture 210, photoelectric sensor 230, and second fixture 220 are integrated into a single unit via a tray 250 to facilitate fixing the relative positions of the first fixture 210 and the second fixture 220. Specifically, the width of the tray 250 is less than or equal to the internal width of the heating chamber 240. The tray 250 defines a first placement area and a second placement area arranged along a first direction. The first placement area is used to house the first fixture 210, and the second placement area is used to house the second fixture 220. The tray 250 is a purely mechanical component, exemplarily constructed as a metal plate, and also collects mouse excrement during the measurement process for easy cleaning with water after the experiment. It also integrates a function to fix the mouse tail, keeping it stable and immobile during the measurement process.

[0035] According to any of the above embodiments, refer to Figure 8 The photoelectric sensor 230 includes a built-in air pump 212, an air bladder 213, an infrared pair 211, and a heating element 214. The air bladder 213 is supplied with air by the air pump 212 and functions to block / restore blood flow during measurement. Simultaneously, the air pump 212 also supplies air to the infrared pair 211, providing a balancing pressure to resist vascular pressure during measurement. The heating element 214 is located behind the air bladder 213, providing a warm environment for the rat's tail to promote blood circulation. The air bladder 213, infrared pair 211, and heating element 214 are all hollow cylinders, and corresponding through holes are provided on both sides of the photoelectric sensor 230 housing. The center lines of the cylinders of each component coincide, and during measurement, the rat's tail passes sequentially through the air bladder 213, infrared pair 211, and heating element 214.

[0036] It is worth noting that in existing technologies, heating only the mouse's body results in a low tail temperature, small blood pressure and pulse amplitude, and significant interference. Furthermore, the mouse's body needs to be heated to a relatively high temperature, which can easily lead to suffocation. In contrast, the sensor in this embodiment has a heating function, and the tail is heated independently via a heating tube, allowing for separate temperature control from the body. This provides precise temperature comfort without hindering experimental operations. The overall volume requiring heating, including the heating chamber and the sensor, is smaller, resulting in lower heat loss and higher heating efficiency.

[0037] Furthermore, compared to existing technologies where the pulse-blocking air pump is placed in the main unit and connected to each measurement channel via air tubing, the presence of multiple channels and connecting tubing requires a relatively large air volume from the air pump. This necessitates either selecting a larger air pump or adding an air tank, resulting in a larger main unit size, cluttered tubing, and unstable inflation / deflation times. In contrast, this application's embodiment integrates a compact ultrasonic air pump and sensor into a single unit, resulting in shorter tubing, higher efficiency, and a more compact main unit without cumbersome tubing connections.

[0038] During testing, the user connects cable 243; power on, and the heating chamber 240 begins preheating. The experimental mouse is then placed inside the heating chamber 240 and secured using the first restraint 210. The head cover 212 and tail clip are adjusted to the appropriate positions to restrain the mouse. The first restraint 210 is placed on the tray 250, and the mouse tail is then passed through the second restraint 220 and the photoelectric sensor 230, securing the photoelectric sensor 230 and the tail. The tray 250 is placed on the preheated heating chamber 240, and its position is adjusted to ensure that the first restraint 210 is completely covered by the heating chamber 240, while the photoelectric sensor 230 is exposed outside the heating chamber 240. Finally, pulse data is measured using PC software.

[0039] The above description is merely a preferred embodiment of this utility model. It should be understood that this utility model is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the concept described herein through the above teachings or related technologies or knowledge. Modifications and variations made by those skilled in the art that do not depart from the spirit and scope of this utility model should be protected within the scope of the appended claims.

Claims

1. A non-invasive blood pressure measurement system based on rat tail, characterized in that, include: Measurement host; The detection component includes: a first fixture and a second fixture, the first fixture and the second fixture being arranged sequentially along a first direction, the first fixture being used to fix the mouse body and the second fixture being used to fix the mouse tail; wherein, a photoelectric sensor is also provided next to the second fixture, the photoelectric sensor being electrically connected to the measuring host and transmitting data; The detection assembly also includes a heating chamber, which is covered by the first fixture, and the second fixture and the photoelectric sensor are located outside the covered area of ​​the heating chamber; The heating chamber has an open side in the first direction, and a connection socket is provided on the open side for connecting a photoelectric sensor. A cable is provided on the other side of the heating chamber in the first direction for connecting to the measuring host. The photoelectric sensor uses the heating chamber as an intermediary to transmit data and draw power from the measuring host. The photoelectric sensor includes a built-in air pump, an air bladder, an infrared pair, and a heating tube. The air pump is used to inflate the air bladder, the air bladder is used to compress the rat's tail, the infrared pair is used to test the rat's tail blood pressure, and the heating tube is used to be fitted onto the rat's tail and heat the tail.

2. The rat tail non-invasive blood pressure measurement system according to claim 1, characterized in that: The first fixture includes a cage body and a head cover, and the first fixture is a mechanical component.

3. The rat tail non-invasive blood pressure measurement system according to claim 2, characterized in that: The cage body is a hollow cylindrical shape, and through holes are formed in at least a portion of the periphery of the cage body.

4. The rat tail non-invasive blood pressure measurement system according to claim 1, characterized in that: The detection component also includes a tray, the width of which is less than or equal to the width inside the heating chamber. The tray defines a first placement area and a second placement area arranged along a first direction. The first placement area is used to set the first fixture, and the second placement area is used to set the second fixture.

5. The rat tail non-invasive blood pressure measurement system according to claim 4, characterized in that: The tray is a metal plate.

6. The rat tail non-invasive blood pressure measurement system according to claim 1, characterized in that: It also includes a PC with software installed on it. The PC and the measurement host communicate via a USB cable, and the software processes the acquired data.

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