Simple nerve block injection pressure monitoring device

Abstract

The utility model discloses a simple nerve blockage injection pressure monitoring device belongs to the field of medical devices, including three -way valve, check valve and hollow columnar piece, syringe and extension pipe butt joint in the left and right two ends of three -way valve, hollow columnar piece butt joint in the middle one end of three -way valve, the check valve is provided with in the hollow columnar piece butt joint of three -way valve, and the opening of check valve faces to the hollow columnar piece, the injection pressure of real -time monitoring device can avoid the interference of the residual gas in the device system when local anesthetic back -and -forth and injection simultaneously.

Description

Technical Field

[0001] This utility model relates to the field of medical devices, and in particular to a simple nerve block injection pressure monitoring device. Background Technology

[0002] Based on existing research, Tsui et al. were the first to propose monitoring injection pressure using compressed air and named it the Compressed Air Injection Technique (CAIT). The authors demonstrated in an in vitro model that, within a closed syringe and needle system, varying degrees of air compression within a hollow cylindrical body resulted in a corresponding linear increase in pressure (a slope of 0.98 over a wide range of compression percentages), thus reliably proving Boyle's Law. The study found that when the air within the hollow cylindrical body was compressed by 50%, the net pressure generated at resting pressure (atmospheric pressure) was 745 mmHg (14.4 psi), slightly below the recommended safe threshold for Opening Injection Pressure (OIP) (15-20 psi), regardless of the size and diameter of the various syringes and needles tested.

[0003] Recently, Patil et al. proposed an alternative solution based on Boyle's law, which they call the Improved Pressure Gauge (IPG). The method involves connecting a three-way valve between the syringe and the needle, and connecting a 1ml syringe containing 1ml of air (the piston of this auxiliary syringe is extended to the end to ensure 1ml of air is present at the start of injection) to the three-way valve. When pressure is applied to the upstream syringe, any resistance downstream of the piston will compress the air in the 1ml syringe, causing the liquid level to move towards the air. The pressure can be determined by observing the reading of the liquid level on the 1ml syringe scale.

[0004] However, its disadvantages are that the three-way valve needs to be moved when pulling back to prevent air from entering the syringe, and the syringe may retract due to the high pressure when pushing, which may cause errors. Utility Model Content

[0005] The present invention aims to provide a simple nerve block injection pressure monitoring device to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A simple nerve block injection pressure monitoring device, the monitoring device comprising a three-way valve, a one-way valve and a hollow cylindrical component;

[0008] The hollow cylindrical member is connected to one end of the middle of the three-way valve, and the one-way valve is located at the connection between the hollow cylindrical member and the three-way valve. The flow direction of the one-way valve is towards the hollow cylindrical member.

[0009] The three-way valve can be connected to a syringe and an extension tube at its left and right ends, respectively.

[0010] The hollow cylindrical component has a 5cm scale line.

[0011] Preferably, the one-way valve is either a one-way diaphragm valve or a ball valve.

[0012] Compared with the prior art, the present invention has the following beneficial effects:

[0013] This invention incorporates a one-way valve and a graduated hollow cylindrical object on a three-way valve, which allows for real-time observation and evaluation of injection pressure while avoiding the need to frequently move the three-way valve during aspiration. It also prevents errors caused by the syringe piston retracting due to excessive pressure.

[0014] This invention achieves monitoring of initial injection pressure through a simple combination of parts, has low manufacturing cost, is easy to promote, and has good prospects for commercialization. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of a simple nerve block injection pressure monitoring device.

[0016] The reference numerals in the accompanying drawings include:

[0017] 1. Syringe; 2. Three-way valve; 3. Extension tube; 4. Hollow cylindrical part; 5. One-way valve; 6. Scale marks. Detailed Implementation

[0018] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments:

[0019] like Figure 1 As shown, a simple nerve block injection pressure monitoring device includes a three-way valve 2, a one-way valve 5, and a hollow columnar component 4.

[0020] The hollow columnar member 4 is connected to one end of the middle of the three-way valve 2, and the one-way valve 5 is located at the connection between the hollow columnar member 4 and the three-way valve 2. The flow direction of the one-way valve 5 is towards the hollow columnar member 4.

[0021] The three-way valve 2 can be connected to syringe 1 and extension tube 3 at its left and right ends, respectively. (Note: Figure 1 The syringe 1 and extension tube 3 mentioned above are not simple nerve block injection pressure monitoring devices.

[0022] The functions of each component are as follows:

[0023] 1. Syringe 1: Syringe 1 containing local anesthetic is used to inject the medication;

[0024] 2. Three-way valve 2: Connects to syringe 1, extension tube of nerve block needle 3, and hollow cylindrical object with graduations;

[0025] 3. Extension tube 3: Connects to the nerve block needle

[0026] 4. Hollow cylindrical object: When syringe 1 is injected, the pressure will push open the one-way valve, causing the liquid level to rise and the air to be compressed. The degree of liquid level rise is used to assess OIP (initial injection pressure), thereby avoiding excessive injection pressure that could cause nerve damage.

[0027] 5. One-way valve 5: Because it is necessary to aspirate when injecting drugs, in order to prevent gas from being drawn back into syringe 1;

[0028] 6. Scale line 6: The pressure is assessed by measuring the liquid level at scale line 6.

[0029] Working principle of the device:

[0030] Opening injection pressure (OIP) is the pressure required to overcome the hydrostatic resistance of the syringe 1 (including syringe 1, connecting tubing, and needle) and the resistance of the tissue. When injection begins, the pressure throughout the system starts to rise as the force on the syringe 1 piston gradually increases. According to Pascal's Law, the pressure throughout the system is equal for all components (syringe 1, tubing, needle, and tissue) before fluid flow; this is the static phase. Once the pressure within the system overcomes the static resistance, OIP is reached, inducing fluid flow. Therefore, OIP represents the pressure applied to the tissue at the moment flow begins. Because the pressure within the system is the same before reaching the opening injection pressure, and because OIP is independent of the size and / or diameter of syringe 1, connecting tubing, and needle, this means that OIP can be measured at any point in the system (e.g., at the interface between syringe 1 and connecting tubing).

[0031] Dynamic injection pressure refers to the pressure existing within the system after a flow relationship has been established. Because the fluid flow at this point is affected by various factors, including the radius and length of the syringe 1, connecting tube, and needle, as well as the density and viscosity of the solution, it is difficult to accurately calculate the pressure at the needle tip. This is precisely the pressure that needs to be monitored when exploring PNB-related nerve injuries. However, it is certain that only when the pressure in syringe 1 is higher than the pressure at the needle tip can fluid flow be stimulated, propelling the local anesthetic forward. Therefore, maintaining a low dynamic injection pressure in real time throughout the injection process is in line with safety strategies.

[0032] Injection pressure monitoring device based on Boyle's law

[0033] Boyle's Law states that in a closed system containing a compressible gas, the product of pressure and volume always remains equal (i.e., P1*V1 = P2*V2, where P1 and V1 are the initial pressure and volume, respectively, and P2 and V2 are the final pressure and volume). For example, if a syringe containing 10 ml of local anesthetic and 10 ml of air is injected until the gas volume is reduced by half (5 ml), the pressure inside the syringe will double.

[0034] If P1*V1 = P2*V2, and V2 is compressed to half the size of V1, then P2 will increase to twice the size of P1. The increased pressure is the OIP (Initial Injection Pressure), which is one atmosphere. The OIP is 760 mmHg, equivalent to 14.6959 psi, which is within the recommended OIP safety threshold (15-20 psi).

[0035] Based on the research materials above, the specific working principle of this device is as follows:

[0036] Connect this device to the extension tube of the syringe and the nerve block needle. When injecting local anesthetic, the injection pressure gradually increases within the system to overcome the initial injection pressure. This injection pressure compresses the air within the hollow cylinder, causing the liquid level to rise. Observe the liquid level reading on the hollow cylinder to assess the injection pressure in real time. When it is necessary to withdraw the syringe to determine whether the needle tip has entered a blood vessel or pleural cavity, the one-way valve prevents air from entering the entire injection system from the hollow cylinder.

[0037] The above descriptions are merely embodiments of the present invention, and common knowledge such as specific technical solutions and / or characteristics are not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the technical solutions of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A simple nerve block injection pressure monitoring device, characterized in that: The monitoring device includes a three-way valve (2), a one-way valve (5), and a hollow cylindrical component (4); The hollow columnar member (4) is connected to one end of the middle of the three-way valve (2), and the one-way valve (5) is located at the connection between the hollow columnar member (4) and the three-way valve (2). The flow direction of the one-way valve (5) is towards the hollow columnar member (4). The three-way valve (2) can be connected to a syringe (1) and an extension tube (3) at its left and right ends, respectively; The hollow cylindrical component (4) has a 5cm scale line (6).

2. The simplified nerve block injection pressure monitoring device according to claim 1, characterized in that: The one-way valve (5) is either a one-way diaphragm valve or a ball valve (5).

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