A series-parallel shape memory alloy vertebral stent

Abstract

The present invention provides a series-parallel shape memory alloy vertebral stent, belonging to the field of medical device technology, comprising a plurality of parallel monomers connected in series, wherein the parallel monomers include a plurality of stent monomers, wherein the stent monomers are cross-connected in parallel to form a parallel monomer, and the parallel monomers are made of a shape memory alloy material that meets biocompatibility requirements, so that the parallel monomers can be in a contracted state or an expanded state at different temperatures. The present invention has a simple structure and is easy to operate and use. It can be used in conjunction with existing general-purpose outer sleeve vertebral shaping instruments, significantly reducing economic costs. The present invention only uses the stent to achieve the function of supporting the vertebral body, and does not require filling with bone cement, thereby avoiding the problem of bone cement leakage, effectively preventing bone cement from burning and damaging nerves and other tissues, and can effectively alleviate the patient's surgical pain and reduce postoperative complications.

Description

Technical Field

[0001] The present invention belongs to the technical field of medical devices, and in particular relates to a series-parallel shape memory alloy vertebral stent. Background Art

[0002] With the advent of an aging society, the incidence of osteoporotic fractures is increasing annually. The vertebrae are the most vulnerable site for osteoporosis-related fractures. According to reports in the United States, approximately 1.5 million patients suffer osteoporosis-related fractures each year, including 700,000 vertebral compression fractures, and this number is expected to continue to rise. One-third of these patients experience chronic pain, and the majority are elderly women. In my country, approximately 4 million people suffer osteoporotic compression fractures annually, of which over 1.7 million experience pain, and 700,000 require hospitalization. Traditional treatment for elderly patients with vertebral compression fractures due to osteoporosis has long relied on bed rest, oral analgesics, and external bracing. However, these treatments only temporarily alleviate pain symptoms in some patients. Furthermore, prolonged bed rest can worsen osteoporosis, further compressing the vertebrae, exacerbating pain and kyphosis, leading to a decrease in chest volume, impaired ventilation, hypoxia, and cardiopulmonary dysfunction. This can significantly reduce patients' quality of life and, in severe cases, increase mortality. Osteoporosis complicates surgical procedures and can lead to dangerous secondary lesions. Surgical intervention is now rarely used unless combined with neurological compression symptoms warrants decompression. In 1987, Galibert et al. first reported percutaneous vertebroplasty (PVP) with bone cement injected into the vertebral body. This technique was applied to the treatment of osteoporotic vertebral compression fractures (OVCF) in 1990. In 1998, Reiley et al. in the United States designed percutaneous kyphoplasty (PKP). Vertebroplasty has been used in my country since 1999, and for over 20 years, it has become an effective treatment for osteoporotic vertebral compression fractures in the elderly. Its minimally invasive and reliable analgesic effects have earned it widespread acceptance among orthopedic surgeons and patients. However, the most commonly used filler, polymethyl methacrylate (PMMA), has inherent disadvantages, including monomer toxicity, heat generation, and leakage, making it unsuitable for use in young patients. Finding or optimizing the design of a less damaging and better tissue-compatible alternative material has been a research hotspot in interdisciplinary fields such as mechanics, materials science, and medicine in recent years. Summary of the Invention

[0003] In view of this, the present invention aims to propose a series-parallel shape memory alloy vertebral stent with a simple structure and easy operation. The stent alone can support the vertebral body without the need for filling with bone cement, thereby avoiding the problem of bone cement leakage and effectively preventing bone cement from burning and damaging nerves and other tissues. It can effectively alleviate the patient's surgical pain and reduce postoperative complications.

[0004] To achieve the above-mentioned purpose, the technical solution of the present invention is implemented as follows: a series-parallel shape memory alloy vertebral stent, comprising a plurality of parallel monomers connected in series, the parallel monomers comprising a plurality of stent monomers, the stent monomers being cross-connected in parallel to form a parallel monomer, the parallel monomers being made of a shape memory alloy material that meets the requirements of biocompatibility, so that the parallel monomers can be in a contracted state or an expanded state at different temperatures.

[0005] Furthermore, a plurality of the parallel monomers are connected in series via connecting ribs.

[0006] Furthermore, the stent monomer is a symmetrical closed circular ring structure having a convex portion and a concave portion, and the circular ring structure is an M-shaped structure after being unfolded.

[0007] Furthermore, the shape memory alloy material is a nickel-titanium shape memory alloy that meets biocompatibility requirements.

[0008] Furthermore, the parallel monomers stretch and shrink along the axis direction of the parallel monomers in the contracted state, and the final contracted state is a thin tubular structure; when the parallel monomers are in the expanded state, the upper and lower ports are both open, and the circumferential side surfaces are a mesh structure.

[0009] Furthermore, the parallel monomers are bilaterally symmetrical along their central axes.

[0010] Furthermore, the cross section of the parallel monomer is circular, and the circumferential side surface of the parallel monomer is a mesh hole structure.

[0011] Furthermore, the diameters of different cross sections of the parallel monomers are all equal when they are expanded into a mesh shape; and the diameters of different cross sections of the parallel monomers are all equal when they are contracted into a tubular shape.

[0012] Furthermore, the surfaces of the parallel monomers are treated to reduce surface roughness.

[0013] Compared with the prior art, the series-parallel shape memory alloy vertebral stent described in the present invention has the following advantages:

[0014] (1) The present invention can support the vertebral body by using only a stent, without the need for filling bone cement, thereby avoiding the problem of bone cement leakage and effectively preventing bone cement from burning and damaging nerves and other tissues;

[0015] (2) After being implanted in the human body, the present invention can expand and obtain a larger supporting force with a smaller expansion radius, thereby playing the role of supporting the fractured vertebral body. It has a simple structure and is easy to operate.

[0016] (3) The mesh-like hole structure around the vertebral stent creates good conditions for the subsequent regrowth of bone tissue, and can ensure the connection between the vertebral stent and the surrounding bone tissue, thus well fixing the vertebral stent to the vertebral body;

[0017] (4) Nickel-titanium shape memory alloy has the advantages of good biocompatibility, high strength, fatigue resistance, non-magneticity, and no toxic side effects, and is suitable for long-term vertebral stent implantation;

[0018] (5) The vertebral stents arranged in series and parallel can provide a large supporting force, which is close to the strength of vertebral segment compression failure;

[0019] (6) The surface of the vertebral stent is smooth, which effectively avoids the damage to the surrounding bone tissue caused by the implantation of the vertebral stent;

[0020] (7) Implantation into the compressed vertebral body through a minimally invasive channel effectively alleviates the patient's surgical pain, reduces postoperative complications, and significantly improves the patient's quality of life, making minimally invasive surgery simple, convenient, and highly controllable;

[0021] (8) The present invention can be used in conjunction with existing universal outer sleeve vertebral body shaping instruments, which can significantly reduce economic costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings, which constitute part of the present invention, are provided to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are provided to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0023] Figure 1 This is a schematic structural diagram of a series-parallel shape memory alloy vertebral stent according to an embodiment of the present invention;

[0024] Figure 2 This is a front view of the series-parallel shape memory alloy vertebral stent according to an embodiment of the present invention;

[0025] Figure 3 This is a left side view of the series-parallel shape memory alloy vertebral stent according to an embodiment of the present invention;

[0026] Figure 4 for Figure 3 Schematic diagram after rotating 45° counterclockwise or clockwise around the central axis of the vertebral body support;

[0027] Figure 5 for Figure 4 Schematic diagram in the contracted state;

[0028] Figure 6 This is a schematic structural diagram of the parallel monomers according to an embodiment of the present invention;

[0029] Figure 7 This is a front view of the parallel monomers according to an embodiment of the present invention;

[0030] Figure 8 A top view of the parallel monomers according to an embodiment of the present invention;

[0031] Figure 9 This is a schematic structural diagram of a stent monomer according to an embodiment of the present invention;

[0032] Figure 10 This is a schematic diagram of the expansion of the stent monomer according to an embodiment of the present invention.

[0033] Description of reference numerals:

[0034] 1. Parallel unit; 2. Connecting rib; 3. Bracket unit. DETAILED DESCRIPTION

[0035] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0036] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0037] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0038] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0039] like Figures 1-10 As shown, the present invention is a series-parallel shape memory alloy vertebral stent, including a plurality of parallel monomers 1 connected in series. Different numbers of the parallel monomers 1 are selected for series connection according to the actual needs of different patients, thereby improving practicality. The parallel monomers 1 include a plurality of stent monomers 3, which are cross-connected in parallel to form one parallel monomer 1. The parallel monomers 1 are made of a shape memory alloy material that meets biocompatibility requirements, so that the parallel monomers 1 can present a contracted state or an expanded state at different temperatures. Specifically, they are in a contracted state at low temperatures (0-5°C) and return to the memorized expanded state at human body temperature (30-37°C). Based on the material properties of the memory alloy, the vertebral stent is in a shrinkable tubular shape at low temperatures (0-5°C) and can be placed in an outer sleeve used with a general vertebral shaping instrument. At human body temperature (30-37°C), it returns to a memory expansion network. The vertebral stents arranged in series and parallel can provide a large supporting force. When the vertebral body compression displacement is 5mm, the supporting force provided by the vertebral stent is about 1000N, which is close to the strength of vertebral segment compression failure. Therefore, after being implanted into the human body, it can be expanded with a small expansion radius to obtain a large supporting force, playing the role of supporting the fractured vertebra. The structure is simple, the operation is easy, and it meets clinical requirements. The present invention can achieve the function of supporting the vertebral body by using only the vertebral stent, without the need to fill bone cement, thereby avoiding the problem of bone cement leakage and effectively preventing bone cement from burning and damaging nerves and other tissues. Under controllable temperature conditions, it is implanted into the compressed vertebral body through a minimally invasive channel, making the minimally invasive surgery simple and convenient, and highly controllable.

[0040] The plurality of parallel cells 1 are connected in series via connecting ribs 2 .

[0041] The stent monomer 3 is a symmetrical closed circular ring structure having a convex portion and a concave portion. The circular ring structure is an M-shaped structure when unfolded.

[0042] The shape memory alloy material is a nickel-titanium shape memory alloy that meets biocompatibility requirements. Nickel-titanium shape memory alloy has the advantages of good biocompatibility, high strength, fatigue resistance, non-magneticity, and no toxic side effects, and is suitable for long-term vertebral stent implantation.

[0043] The parallel monomer 1 stretches and contracts along the axis direction of the parallel monomer 1 when in the contracted state, and the final contracted state is a thin tubular structure; the upper and lower ports of the parallel monomer 1 are both open when in the expanded state, and its circumferential side surface is a mesh structure.

[0044] The parallel monomer 1 is bilaterally symmetrical along its central axis.

[0045] The cross section of the parallel monomer 1 is circular, and the circumferential side of the parallel monomer 1 is a mesh hole structure. The existence of the mesh hole structure creates good conditions for the subsequent regrowth of bone tissue, and can ensure that the vertebral stent is connected to the surrounding bone tissue, thereby fixing the vertebral stent and the vertebral body well.

[0046] The diameters of different cross sections of the parallel monomers 1 are all equal when they are expanded into a mesh shape; the diameters of different cross sections of the parallel monomers 1 are all equal when they are contracted into a tubular shape, thereby ensuring that the supporting force of the vertebral support in the vertebral cavity can be evenly distributed, ensuring the support requirements after compression fracture reduction, and thus achieving normal vertebral height.

[0047] The surface of the parallel monomer 1 is treated to reduce the surface roughness, which effectively avoids the implantation of the vertebral stent to damage the surrounding bone tissue.

[0048] During vertebroplasty, a vertebral stent is used in conjunction with a common existing vertebral shaping instrument. The vertebral stent in a contracted state is placed at one end of the outer sleeve, and the inner sleeve is placed at the other end of the outer sleeve away from the vertebral stent. Through a minimally invasive incision, the inner sleeve is pushed to deliver the vertebral stent to the diseased vertebra that needs to be expanded. Then the inner sleeve and the outer sleeve of the vertebral stent are withdrawn in turn. As the temperature rises, when the vertebral stent reaches the human body temperature (30-37°C), the vertebral stent slowly expands into a mesh shape, providing support force to expand the fractured vertebra, thereby achieving the purpose of treating vertebral compression fractures. The outer sleeve and the inner sleeve are the existing basis.

[0049] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A series-parallel shape memory alloy vertebral stent, characterized by: The invention comprises a plurality of parallel monomers (1) connected in series, and different numbers of parallel monomers (1) can be connected in series according to actual needs. The parallel monomers (1) comprise a plurality of support monomers (3), and the support monomers (3) are cross-connected in parallel to form one parallel monomer (1). The parallel monomers (1) are made of a shape memory alloy material that meets the requirements of biocompatibility, so that the parallel monomers (1) can present a contracted state or an expanded state at different temperatures. The support monomers (3) are symmetrical closed circular ring structures, and the circular ring structure has a convex part and a concave part. At the same time, the circular ring structure is an M-shaped structure after being unfolded. The parallel monomers (1) are bilaterally symmetrical along their central axis. The parallel monomer (1) stretches and contracts along the axis direction of the parallel monomer (1) when in the contracted state, and the final contracted state is a thin tube structure; the upper and lower ports of the parallel monomer (1) are both open when in the expanded state, and the circumferential side surface thereof is a mesh structure; The diameters of different cross sections of the parallel monomers (1) are all equal when the parallel monomers (1) are expanded into a mesh shape; and the diameters of different cross sections of the parallel monomers (1) are all equal when the parallel monomers (1) are contracted into a tubular shape.

2. The series-parallel shape memory alloy vertebral stent according to claim 1, characterized in that: The plurality of parallel monomers (1) are connected in series via connecting ribs (2).

3. The series-parallel shape memory alloy vertebral stent according to claim 1, characterized in that: The shape memory alloy material is a nickel-titanium shape memory alloy that meets biocompatibility requirements.

4. The series-parallel shape memory alloy vertebral stent according to claim 1, characterized in that: The cross section of the parallel monomer (1) is circular, and the circumferential side surface of the parallel monomer (1) is a mesh hole structure.

5. The series-parallel shape memory alloy vertebral stent according to claim 1, characterized in that: The surface of the parallel monomer (1) is treated to reduce surface roughness.

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