Integrated device for long-term monitoring of in-situ electrochemical impedance spectroscopy of magnesium and alloy thereof in bone

Abstract

The utility model provides an integrated device for long-term monitoring of in-situ electrochemical impedance spectroscopy of intraosseous magnesium and alloy thereof, and relates to the technical field of in-vivo electrochemical measurement. Comprising a medical catheter, the medical catheter is completely arranged in a muscle and is filled with epoxy resin, and one ends of a magnesium column, a drainage tube and a platinum wire are inserted into the epoxy resin in parallel; one ends of the magnesium column and the platinum wire are arranged in the bone below the muscle, and one end of the drainage tube is arranged on the interface of the muscle and the bone; the other end of the magnesium column is connected with one end of the electrode lead in the muscle; the other end of the electrode lead and the other end of the platinum wire are connected with an electrochemical device outside the muscle, the other end of the drainage tube is connected with a first end of a three-way tube outside the muscle, agar is arranged at a second end of the three-way tube and is placed in a saturated KCl solution, a reference electrode is arranged on the saturated KCl solution, and the reference electrode is connected with the electrochemical device. The third end of the three-way pipe is connected with the injector. According to the utility model, the live welfare index is improved, and the long-term measurement of the impedance spectrum is ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of in vivo electrochemical measurement, and in particular provides an integrated device for long-term in-situ electrochemical impedance spectroscopy monitoring of intrabone magnesium and its alloys. Background Art

[0002] The influence of magnesium alloys in the field of orthopedics is increasing day by day, which is attributed to its unique properties: good degradation performance, strong mechanical properties, high biosafety, and degradation products that promote osteogenesis. However, due to the very high standard electrode potential of magnesium alloys and their extremely active properties, they are very easy to dissolve in bones, react physically and chemically with organic and inorganic substances in the bone marrow, and produce corrosion products on the surface of the matrix. Over time, the physical structure and chemical properties of corrosion products on the surface of magnesium alloys will also change, greatly affecting the protective properties of corrosion products, and thus affecting the corrosion resistance of magnesium alloys.

[0003] The methods currently reported for evaluating the corrosion resistance of magnesium and its alloys in bone are mainly weight loss method, CT method, and X-ray method. The weight loss method is to calculate the weight difference before and after the sample is implanted. This method requires the material to be removed from the living body regularly, which is time-consuming, costly, and very likely to cause the death of the living body. The latter two methods estimate the degradation rate by observing the size of the sample remaining in the bone. They are qualitative results and cannot observe subtle changes in the sample in a short period of time. Frequent CT scans cause great damage to animals and operators due to the radiation, and the cost is also very high. In addition, none of these three methods can characterize the time-dependent evolution of the protectiveness of corrosion products on the surface of magnesium and its alloys in bone.

[0004] Electrochemical impedance spectroscopy has been used to evaluate the corrosion resistance of magnesium and its alloys in vivo, but there are few reported cases. Patent EP2260884A1 discloses a device for in situ monitoring of the corrosion resistance of magnesium and its alloys in muscle. The document Journal of Alloys and Compounds 848 (2020) 156506 reports a device for in situ monitoring of the corrosion resistance of magnesium and its alloys in bone. Because the resistance difference between the inside and outside of the bone is large, it is difficult for electrons and ions to be transmitted between the inside and outside of the bone, so all electrodes must be placed in the bone. However, in the traditional electrode combination and the electrode combination disclosed in EP2260884A1, the counter electrode, the working electrode, and the reference electrode are far apart. If all are implanted in the bone, it will lead to a large number of holes drilled in the bone or an increase in the aperture of the hole. The consequence is that the bone trauma is large, and the living body is very likely to die prematurely, and it is difficult to achieve impedance spectrum measurement, especially long-term measurement. In the electrode combination reported in the literature (Journal of Alloys and Compounds 848(2020)156506), all three electrodes are embedded in the bone, so the required drilling hole diameter is larger, which greatly increases the risk of living death, and thus affects the long-term measurement of the impedance spectrum; and the platinum wire used in the literature is short in length in the bone, so the working surface area of ​​the platinum wire is very small relative to the surface area of ​​the magnesium alloy, which is not conducive to the accurate measurement of the impedance spectrum. Utility Model Content

[0005] The utility model aims to provide an integrated device for long-term in-situ electrochemical impedance spectroscopy monitoring of magnesium and its alloys in bone.

[0006] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0007] A device for measuring in-situ electrochemical impedance spectroscopy of magnesium and its alloys in bone, comprising a medical catheter, which is completely placed in the muscle, filled with epoxy resin, and a magnesium column, a drainage tube and one end of a platinum wire are inserted into the epoxy resin in parallel; one end of the magnesium column and the platinum wire are placed in the bone under the muscle, and one end of the drainage tube is placed at the interface between the muscle and the bone;

[0008] The other end of the magnesium column is connected to one end of the electrode lead inside the muscle; the other end of the electrode lead and the other end of the platinum wire are connected to an electrochemical device outside the muscle, the other end of the drainage tube is connected to the first end of the three-way tube outside the muscle, agar is placed on the second end of the three-way tube, the agar is placed in a saturated KCl solution, a reference electrode is placed on the saturated KCl solution, the reference electrode is connected to the electrochemical device, and the third end of the three-way tube is connected to a syringe.

[0009] Furthermore, the magnesium column is made of magnesium or a magnesium alloy and is a column.

[0010] Furthermore, the material of the medical catheter and the drainage tube is polyethylene.

[0011] Furthermore, the platinum wire is vertical in the muscle, is spiral in the bone and is wound around the outside of the magnesium column, and the drainage tube is located between the magnesium column and the platinum wire.

[0012] Furthermore, the syringe is used to inject serum and extract serum before and during impedance spectrum measurement, and is closed at other times.

[0013] The beneficial effects of the utility model are:

[0014] (1) The device of the utility model adopts an integrated electrode, which avoids electrode dispersion, greatly reduces the diameter of the hole drilled on the bone, greatly reduces bone trauma, and improves the welfare index of the living body while ensuring long-term measurement of the impedance spectrum.

[0015] (2) The device described in the utility model uses an integrated electrode to measure the electrochemical impedance spectroscopy in the bone. The measurement results of the electrochemical impedance spectroscopy at different periods can reflect the evolution of the resistance of the corrosion products on the surface of the magnesium alloy during the corrosion process, which solves the problem that the traditional weightlessness method, CT method and X-ray method cannot monitor the evolution of the resistance of the corrosion products on the surface of magnesium and its alloys in real time.

[0016] (3) The evolution of the resistance of the corrosion products measured by the device of the utility model reflects the time-dependent protective performance of the corrosion products, which is beneficial to the prediction of the degradation behavior of magnesium and its alloys in bones and the evaluation of the service life.

[0017] (4) The subsequent measurement process of the device described in the utility model is simple and does not require re-implantation surgery. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Schematic diagram of the integrated device structure for long-term in-situ electrochemical impedance spectroscopy monitoring of magnesium and its alloys in bone.

[0019] Figure numerals: 1. medical catheter, 2. epoxy resin, 3. muscle, 4. magnesium column, 5. platinum wire, 6. drainage tube, 7. electrode lead, 8. electrochemical device, 9. bone, 10. three-way pipe, 11. agar, 12. saturated KCl solution, 13. reference electrode, 14. syringe. DETAILED DESCRIPTION

[0020] The present invention will be further described below in conjunction with the embodiments and the accompanying drawings, but is not limited thereto.

[0021] Example 1

[0022] As attached Figure 1As shown, an integrated device for long-term in-situ electrochemical impedance spectroscopy monitoring of magnesium and its alloys in bone includes a medical catheter 1, which is completely placed in a muscle 3, filled with an epoxy resin 2, a magnesium column 4, a drainage tube 6 and one end of a platinum wire 5 are inserted into the epoxy resin 2 in parallel; the platinum wire 5 is vertical in the muscle 3, the platinum wire 5 is spiral in the bone 9 and is wound around the outside of the magnesium column 4, and the drainage tube 6 is located between the magnesium column 4 and the platinum wire 5. One end of the magnesium column 4 and the platinum wire 5 are placed in the bone 9 under the muscle 3, and one end of the drainage tube 6 is placed at the interface between the muscle 3 and the bone 9; the other end of the magnesium column 4 is connected to one end of the electrode lead 7 in the muscle 3; the other end of the electrode lead 7 and the other end of the platinum wire 5 are connected to the electrochemical device 8 outside the muscle 3, and the other end of the drainage tube 6 is connected to the first end of the three-way tube 10 outside the muscle 3, and the second end of the three-way tube 10 is provided with agar 11, and the agar 11 is placed in a saturated KCl solution 12, and a reference electrode 13 is placed on the saturated KCl solution 12, and the reference electrode 13 is connected to the electrochemical device 8, and the third end of the three-way tube 10 is connected to the syringe 14. The magnesium column 4 is magnesium or magnesium alloy, and is a column. The material of the medical catheter 1 and the drainage tube 6 is polyethylene. The syringe 14 is used to inject and extract serum before and during the impedance spectrum measurement, and is closed at other times.

[0023] Long-term electrochemical impedance spectroscopy monitoring of magnesium and its alloys in bone, using the above device, the specific process is as follows:

[0024] (1) Preparation of serum: Blood was collected from the ear artery of New Zealand rabbits and the supernatant was taken as serum after standing.

[0025] (2) Anesthesia and fixation: 5 ml / kg of 20% urethane was injected into the ear vein of New Zealand rabbits and the rabbits were fixed in the right lateral decubitus position.

[0026] (3) Drilling: The hair of the left hind thigh of the New Zealand rabbit was trimmed, the skin was disinfected, a 4 cm longitudinal incision was made, the biceps femoris was peeled off, the femur was exposed, and the posterior side of the biceps femoris was separated from the femur, and the femoral shaft was drilled transversely.

[0027] (4) Internal electrode: The integrated electrode is implanted into the femoral hole.

[0028] (5) Skin suture: Suture the incision and bandage the wound.

[0029] (6) Injection of serum: Before each measurement of the index, the serum is first injected from the syringe 14 into the location of the integrated device of the present application to form a salt bridge.

[0030] (7) Electrochemical impedance spectroscopy measurement: The measurement time can be determined according to needs.

[0031] (8) Postoperative treatment: After the electrochemical impedance spectroscopy measurement is completed, the serum injected into the integrated device of the present application is sucked out with a syringe 14, the drainage device is closed, and ceftriaxone is injected into the rabbit's abdomen.

[0032] Matters not covered in this utility model are known technologies.

[0033] The above embodiments are only for illustrating the technical concept and features of the utility model, and their purpose is to enable people familiar with the technology to understand the content of the utility model and implement it accordingly, and they cannot be used to limit the protection scope of the utility model. Any equivalent changes or modifications made according to the spirit of the utility model should be included in the protection scope of the utility model.

Claims

1. An integrated device for long-term in-situ electrochemical impedance spectroscopy monitoring of magnesium and its alloys in bone, characterized by: The medical catheter (1) is completely placed in the muscle (3), the medical catheter (1) is filled with epoxy resin (2), and a magnesium column (4), a drainage tube (6) and one end of a platinum wire (5) are inserted into the epoxy resin (2) in parallel; One end of the magnesium column (4) and the platinum wire (5) are placed in the bone (9) under the muscle (3), and one end of the drainage tube (6) is placed at the interface between the muscle (3) and the bone (9); The other end of the magnesium column (4) is connected to one end of the electrode lead (7) inside the muscle (3); the other end of the electrode lead (7) and the other end of the platinum wire (5) are connected to an electrochemical device (8) outside the muscle (3); the other end of the drainage tube (6) is connected to the first end of a three-way tube (10) outside the muscle (3); agar (11) is placed on the second end of the three-way tube (10); the agar (11) is placed in a saturated KCl solution (12); a reference electrode (13) is placed on the saturated KCl solution (12); the reference electrode (13) is connected to the electrochemical device (8); and the third end of the three-way tube (10) is connected to a syringe (14).

2. The integrated device for in-situ electrochemical impedance spectroscopy long-term monitoring of magnesium and its alloys in bone according to claim 1, characterized in that: The magnesium column (4) is made of magnesium or a magnesium alloy and is a column.

3. The integrated device for in-situ electrochemical impedance spectroscopy long-term monitoring of magnesium and its alloys in bone according to claim 1, characterized in that: The medical catheter (1) and the drainage tube (6) are made of polyethylene.

4. The integrated device for in-situ electrochemical impedance spectroscopy long-term monitoring of magnesium and its alloys in bone according to claim 1, characterized in that: The platinum wire (5) is vertical in the muscle (3), is spiral in the bone (9) and is wound around the outside of the magnesium column (4), and the drainage tube (6) is located between the magnesium column (4) and the platinum wire (5).

5. The integrated device for in-situ electrochemical impedance spectroscopy long-term monitoring of magnesium and its alloys in bone according to claim 1, characterized in that: The syringe (14) is used to inject serum and extract serum before and during impedance spectrum measurement, and is in a closed state at other times.

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