A nerve block analgesic system and control method

Abstract

The application discloses a nerve block analgesia system and a control method, wherein the system comprises: a current excitation and monitoring device, which comprises a positive electrode interface and at least four negative electrode interfaces; a catheter tip connected with the positive electrode interface of the current excitation and monitoring device; at least four body surface electrodes connected with the at least four negative electrode interfaces of the current excitation and monitoring device; and the current excitation and monitoring device outputs a current signal with a set size through the positive electrode interface in a monitoring mode, monitors the resistance values of each loop between the positive electrode interface and the at least four negative electrode interfaces, and determines whether the catheter tip is displaced and the displacement direction according to the comparison result of the real-time resistance value of each loop and the corresponding initial resistance value. The application can be used in the whole process of analgesia, including initial positioning, catheter tip displacement monitoring in the indwelling stage and drug position offset correction during displacement.

Description

A nerve block analgesia system and its control method Technical Field

[0001] This invention relates to the field of analgesic equipment technology, and in particular to a nerve block analgesia system and control method. Background Technology

[0002] Intra-neural block analgesia catheters placed near nerves for local anesthetic administration are a common analgesic technique. However, with conventional catheters, the catheter tip often shifts away from the block site due to limb movement, affecting the analgesic effect and leading to analgesia failure and patient suffering. Since the catheter is implanted in the body, it is impossible to directly observe whether the catheter tip has shifted or in what direction, making timely detection even more difficult. Furthermore, when catheter shift occurs, the position can only be manually adjusted before medication can continue; automated correction of medication misalignment is not possible.

[0003] Chinese patent application CN106963458A discloses a positioning indwelling needle for continuous peripheral nerve block and its anesthesia method. It uses a nerve stimulator to release a set amount of stimulation current and observes muscle contraction to determine whether the initial indwelling needle puncture positioning is accurate. However, it cannot monitor subsequent displacement and displacement direction, nor can it achieve automatic correction of drug delivery displacement. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a nerve block analgesia system and control method that enables automated monitoring of catheter displacement.

[0005] Firstly, a nerve block analgesia system is provided, comprising:

[0006] A current excitation and monitoring device, comprising a positive terminal interface and at least four negative terminal interfaces;

[0007] The tip of the conduit is connected to the positive terminal interface of the current excitation and monitoring device;

[0008] At least four body surface electrodes are respectively connected to at least four negative terminals of the current excitation and monitoring device;

[0009] In monitoring mode, the current excitation and monitoring device outputs a current signal of a set magnitude through the positive interface and monitors the resistance value of each loop between the positive interface and at least four negative interfaces. Based on the comparison between the real-time resistance value of each loop and the corresponding initial resistance value, it determines whether the tip of the conduit has shifted and the direction of the shift.

[0010] Furthermore, the tip of the catheter is connected to the positive interface of the current excitation and monitoring device via a conductive wire embedded in the catheter wall.

[0011] Furthermore, the current excitation and monitoring device is also used to detect the change in resistance value in all circuits. If the maximum absolute value of all resistance value changes is greater than the first change threshold, it is considered that the catheter tip is deviating from the nerve. At this time, the current excitation and monitoring device operates in correction mode: it identifies the circuit with the largest increase in resistance value and keeps only that circuit conducting while disconnecting other circuits. Then, the current excitation and monitoring device continuously outputs a preset current signal through the positive interface.

[0012] Furthermore, the preset current signal has a value range of 0.1mA to 5mA.

[0013] Furthermore, determining whether the catheter tip has shifted and the direction of shift based on the comparison between the real-time resistance value of each circuit and the corresponding initial resistance value specifically includes: if the maximum absolute value of the resistance value change in all circuits does not exceed the first change threshold, then it is considered that no shift has occurred; otherwise, it is considered that a shift has occurred, and the circuit with the largest decrease in resistance value is identified, and the orientation of the body surface electrode of that circuit is used as the direction of catheter tip shift.

[0014] Furthermore, in monitoring mode, the current excitation and monitoring device outputs a current signal of a set magnitude through the positive interface at a first preset frequency, and monitors the resistance value of each circuit.

[0015] Furthermore, in monitoring mode, the current excitation and monitoring device first outputs a current signal of a set magnitude through the positive interface at a second preset frequency, and monitors the resistance value of each circuit; if the maximum absolute value of the resistance value change in all circuits is detected to be greater than the second change threshold, the current excitation and monitoring device outputs a current signal of a set magnitude through the positive interface at a third preset frequency, and monitors the resistance value of each circuit; wherein the third preset frequency is greater than the second preset frequency.

[0016] Furthermore, the current excitation and monitoring device includes a power supply module, an excitation current output module, a multiplexer, an operational amplifier, an analog-to-digital converter, a processing module, a display module, a positive interface, and at least four negative interfaces;

[0017] The power supply module supplies power to the current excitation and monitoring device; the excitation current output module is connected to the positive terminal interface; the at least four negative terminals, multiplexer, operational amplifier, analog-to-digital converter, processing module, and display module are connected in sequence; the processing module is also connected to the multiplexer to control the multiplexer to achieve loop switching, so that different negative terminals are connected to the loop; the display module is used to display the monitoring results of the current excitation and monitoring device.

[0018] Secondly, a method for controlling the nerve block analgesia system as described above is provided, including:

[0019] After the catheter tip and body surface electrodes are installed, the current excitation and monitoring device operates in monitoring mode, outputs a current signal of a set magnitude through the positive interface, and monitors the resistance value of each circuit between the positive interface and at least four negative interfaces, and records it as the initial resistance value of each circuit.

[0020] In the operation monitoring mode, the current excitation and monitoring device outputs a current signal of a set magnitude through the positive interface at a preset frequency, and monitors the resistance value of each loop between the positive interface and at least four negative interfaces. Based on the comparison between the real-time resistance value of each loop and the corresponding initial resistance value, it determines whether the tip of the conduit has shifted and the direction of the shift.

[0021] Furthermore, the control methods of the nerve block analgesia system also include:

[0022] The current excitation and monitoring device detects the change in resistance value in all circuits. If the maximum absolute value of all resistance value changes is greater than the first change threshold, it is considered that the catheter tip has deviated from the nerve. At this time, the current excitation and monitoring device operates in correction mode: it identifies the circuit with the largest increase in resistance value and keeps only that circuit conducting while disconnecting the other circuits. Then, the current excitation and monitoring device continuously outputs a preset current signal through the positive interface.

[0023] This invention proposes a nerve block analgesia system and control method, which has the following advantages compared with the prior art: This invention can be applied to the entire analgesia process, including initial positioning, displacement monitoring, and deviation correction. Specifically, during the initial catheter puncture, a stimulating current can be released through a current excitation and monitoring device to observe muscle activity and determine whether the puncture position is accurate, thus achieving puncture-assisted positioning; during the indwelling stage, a current signal is output through the current excitation and monitoring device to monitor the resistance value of each branch, and the value is compared with the initial resistance value of each branch to determine whether the catheter tip has shifted and the direction of shift, thus achieving monitoring of catheter tip shift and shift direction; when excessive catheter tip shift is detected, a current signal is continuously output to a specific branch to guide the local anesthetic to move towards the target nerve, thus achieving deviation correction of the drug administration position. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 is a schematic diagram of a nerve block analgesia system provided in an embodiment of the present invention;

[0026] Figure 2 is a schematic diagram of the current excitation and monitoring device provided in an embodiment of the present invention. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0028] As shown in Figure 1, an embodiment of the present invention provides a nerve block analgesia system, comprising:

[0029] A current excitation and monitoring device 01 includes a positive terminal interface 2 and at least four negative terminal interfaces 3;

[0030] The tip 02 of the conduit is connected to the positive interface 2 of the current excitation and monitoring device 01;

[0031] At least four body surface electrodes 03 are respectively connected to at least four negative terminals 3 of the current excitation and monitoring device 01;

[0032] In monitoring mode, the current excitation and monitoring device 01 outputs a current signal of a set magnitude through the positive interface 2 and monitors the resistance value of each loop between the positive interface 2 and at least four negative interfaces 3. Based on the comparison result of the real-time resistance value of each loop with the corresponding initial resistance value, it determines whether the tip of the conduit 02 has shifted and the direction of shift.

[0033] This analgesia system can be applied to initial positioning: During the initial catheter puncture stage, after the catheter tip 02 is punctured at a certain position, a stimulation current (generally a current signal of 0.5mA~2mA) can be released through the current excitation and monitoring device 01 to observe muscle activity. If the muscles innervated by the target nerve contract rhythmically, the puncture position is considered accurate; otherwise, the puncture position is inaccurate, thus achieving puncture-assisted positioning. This analgesia system can also be applied to displacement monitoring: During the indwelling stage, the current excitation and monitoring device 01 outputs a current signal (generally a current signal of 0.5mA~1mA) at a preset frequency and monitors the resistance value of each circuit, comparing it with the initial resistance value of each circuit. If the maximum absolute value of the resistance change in all circuits does not exceed the first change threshold (set according to the actual situation), it is considered that no displacement has occurred; otherwise, it is considered that displacement has occurred, and the circuit with the largest decrease in resistance value is identified. The orientation of the surface electrode 03 of this circuit is used as the displacement direction of the catheter tip 02, realizing the monitoring of the displacement and displacement direction of the catheter tip 02. Of course, after detecting displacement of the catheter tip 02, the current excitation and monitoring device 01 can be manually controlled to release the stimulating current to observe the muscle activity. If the muscle innervated by the target nerve contracts rhythmically, it is considered that the distance between the catheter tip and the nerve is still within an acceptable range, and continued administration can achieve the expected analgesic effect.

[0034] In some embodiments, in monitoring mode, the current excitation and monitoring device 01 outputs a current signal of a set magnitude through the positive interface 2 at a first preset frequency, and monitors the resistance value of each circuit. The first preset frequency can be every 1 to 8 minutes.

[0035] In some other preferred embodiments, in monitoring mode, the current excitation and monitoring device 01 first outputs a current signal of a set magnitude through the positive interface 2 at a second preset frequency, and monitors the resistance value of each circuit; if the maximum absolute value of the resistance value change in all circuits is detected to be greater than the second change threshold, then the current excitation and monitoring device 01 outputs a current signal of a set magnitude through the positive interface at a third preset frequency, and monitors the resistance value of each circuit; wherein the third preset frequency is greater than the second preset frequency. Considering that the current signal output by the current excitation and monitoring device 01 will stimulate the target nerve and cause some discomfort to the patient, if the monitoring frequency is too high, it will increase the patient's discomfort. Therefore, in this embodiment, a lower monitoring frequency is considered in the early stage. That is, a current signal of a set magnitude is output through the positive interface at a second preset frequency, which can be selected as 5 to 10 minutes each time. When the maximum absolute value of the resistance change in all circuits is detected to be greater than the second change threshold, it indicates that the catheter tip 02 has moved to a certain extent, but it is still within an acceptable range. However, it is necessary to increase the monitoring frequency to detect whether displacement has occurred in time. That is, a current signal of a set magnitude is output through the positive interface at a third preset frequency, which can be selected as 1 to 3 minutes each time. The first change threshold is greater than the second change threshold.

[0036] In some embodiments, the catheter tip 02 is connected to the positive interface 2 of the current excitation and monitoring device 01 via a conductive wire embedded in the catheter wall.

[0037] In some embodiments, as shown in FIG2, the current excitation and monitoring device 01 includes a power supply module (not shown), an excitation current output module 1, a multiplexer 4, an operational amplifier 5, an analog-to-digital converter 6, a processing module 7, a display module 8, a positive interface 2, and at least four negative interfaces 3.

[0038] The power supply module supplies power to the current excitation and monitoring device 01; the excitation current output module 1 is connected to the positive interface 2; the at least four negative interfaces 3, the multiplexer 4, the operational amplifier 5, the analog-to-digital converter 6, the processing module 7, and the display module 8 are connected in sequence; the processing module 7 is also connected to the multiplexer 4 and is used to control the multiplexer 4 to switch the circuit so that different negative interfaces 3 are connected to the circuit; the display module 8 is used to display the monitoring results of the current excitation and monitoring device 01.

[0039] The excitation current output module 1 outputs a current signal of a set magnitude, which is transmitted to the catheter tip 02 via the positive interface 2, then to the body surface electrode 03, and finally back to at least four negative interfaces 3, forming multiple loops. To avoid electromagnetic interference from other loops when detecting the resistance values ​​of each loop, this embodiment uses a multiplexer 4 to achieve sequential switching of multiple loop connections. The multiplexer 4 can be an MC14052B or ADGS5414, etc. The switching of the multiplexer 4 is controlled by the processing module 7, and the switching time can be set, such as switching one loop every 10ms-20ms. The operational amplifier 5 amplifies the voltage, and then the voltage is acquired by the analog-to-digital converter 6 and transmitted to the processing module 7 for resistance value calculation. The display module 8 displays the monitoring results including the resistance value of each loop, the amount of resistance value change, whether there is a shift, and one or more of the following operating modes:

[0040] It should be noted that the number of surface electrodes 03 is selected according to actual needs, generally four to eight. When the number is four, their placement can be evenly distributed on the outer periphery of the part to be monitored, which can satisfy the determination of the most basic displacement direction. As the number of surface electrodes 03 increases, the accuracy of determining the displacement direction can be improved.

[0041] In some preferred embodiments, the current excitation and monitoring device 01 is further used to detect the change in resistance value in all circuits. If the maximum absolute value of all resistance value changes is greater than a first change threshold, it is considered that the catheter tip 02 has deviated from the nerve. At this time, the current excitation and monitoring device 01 operates in correction mode: it identifies the circuit with the largest increase in resistance value and keeps only that circuit conducting while disconnecting the other circuits. Then, the current excitation and monitoring device 01 continuously outputs a preset current signal through the positive interface 2. The preset current signal has a value range of 0.1mA to 5mA.

[0042] The correction mode is used for drug delivery position correction. When excessive displacement of the catheter tip O2 is detected, a current signal is continuously output to a specific branch, which can cause the positively charged local anesthetic (local anesthetics generally have positively charged groups) to move towards the target nerve, thereby correcting the offset of the drug delivery position and thus correcting the effect of tip displacement, thereby avoiding the need for manual readjustment of the catheter tip position.

[0043] This invention also provides a method for controlling a nerve block analgesia system, comprising:

[0044] After the catheter tip 02 and the body surface electrode 03 are installed, the current excitation and monitoring device 01 operates in monitoring mode, outputs a current signal of a set magnitude through the positive interface 2, and monitors the resistance value of each circuit between the positive interface 2 and at least four negative interfaces 3, and records it as the initial resistance value of each circuit.

[0045] In the operation monitoring mode, the current excitation and monitoring device 01 outputs a current signal of a set magnitude through the positive interface 2 at a preset frequency, and monitors the resistance value of each loop between the positive interface 2 and at least four negative interfaces 3. Based on the comparison result of the real-time resistance value of each loop with the corresponding initial resistance value, it determines whether the tip of the conduit 02 has shifted and the direction of the shift.

[0046] Preferably, the control method of the nerve block analgesia system further includes:

[0047] The current excitation and monitoring device 01 detects the change in resistance value in all circuits. If the maximum absolute value of all resistance value changes is greater than the first change threshold, it is considered that the catheter tip 02 is deviating from the nerve. At this time, the current excitation and monitoring device 01 operates in correction mode: it identifies the circuit with the largest increase in resistance value and keeps only that circuit conducting while disconnecting other circuits. Then, the current excitation and monitoring device 01 continuously outputs a preset current signal through the positive interface.

[0048] It is understood that the same or similar parts in the above embodiments can be referred to each other, and the contents not described in detail in some embodiments can be referred to the same or similar contents in other embodiments.

[0049] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A nerve block analgesia system, characterized in that, include: A current excitation and monitoring device, comprising a positive terminal interface and at least four negative terminal interfaces; a conduit tip connected to the positive terminal interface of the current excitation and monitoring device; At least four surface electrodes are connected to at least four negative interfaces of the current excitation and monitoring device. In monitoring mode, the current excitation and monitoring device outputs a current signal of a set magnitude through the positive interface and monitors the resistance value of each loop between the positive interface and the at least four negative interfaces. Based on the comparison between the real-time resistance value of each loop and its corresponding initial resistance value, it determines whether the catheter tip has shifted and the direction of shift. Specifically, determining whether the catheter tip has shifted and the direction of shift based on the comparison between the real-time resistance value of each loop and its corresponding initial resistance value includes: if the maximum absolute value of the resistance change in all loops is not greater than the maximum value of the change in resistance... If the change exceeds the first threshold, it is considered that no displacement has occurred; otherwise, it is considered that displacement has occurred, and the circuit with the largest decrease in resistance value is identified, and the orientation of the surface electrode of the circuit is used as the direction of catheter tip displacement. The current excitation and monitoring device is also used to detect the change in resistance value in all circuits. If the maximum absolute value of all resistance value changes is greater than the first threshold, it is considered that the catheter tip has deviated from the nerve. At this time, the current excitation and monitoring device operates in correction mode: it identifies the circuit with the largest increase in resistance value, and only keeps the circuit conducting while disconnecting the other circuits. Then, the current excitation and monitoring device continuously outputs a preset current signal through the positive interface.

2. The nerve block analgesia system according to claim 1, characterized in that, The tip of the catheter is connected to the positive interface of the current excitation and monitoring device via a conductive wire embedded in the catheter wall.

3. The nerve block analgesia system according to claim 1, characterized in that, The preset current signal has a value range of 0.1mA to 5mA.

4. The nerve block analgesia system according to claim 1, characterized in that, In monitoring mode, the current excitation and monitoring device outputs a current signal of a set magnitude through the positive interface at a first preset frequency, and monitors the resistance value of each circuit.

5. The nerve block analgesia system according to claim 1, characterized in that, In monitoring mode, the current excitation and monitoring device first outputs a current signal of a set magnitude through the positive interface at a second preset frequency, and monitors the resistance value of each circuit; if the maximum absolute value of the resistance value change in all circuits is detected to be greater than the second change threshold, the current excitation and monitoring device outputs a current signal of a set magnitude through the positive interface at a third preset frequency, and monitors the resistance value of each circuit; wherein the third preset frequency is greater than the second preset frequency.

6. The nerve block analgesia system according to any one of claims 1 to 5, characterized in that, The current excitation and monitoring device includes a power supply module, an excitation current output module, a multiplexer, an operational amplifier, an analog-to-digital converter, a processing module, a display module, a positive interface, and at least four negative interfaces. The power supply module supplies power to the current excitation and monitoring device. The excitation current output module is connected to the positive interface. The at least four negative interfaces, the multiplexer, the operational amplifier, the analog-to-digital converter, the processing module, and the display module are connected in sequence. The processing module is also connected to the multiplexer and is used to control the multiplexer to switch loops, allowing different negative interfaces to be connected to the loop. The display module is used to display the monitoring results of the current excitation and monitoring device.

Images