Preparation method of polyester cotton for cranial nerve microvascular decompression, polyester cotton and use thereof

Abstract

The purpose of the present invention is to disclose a preparation method of polyester cotton for cranial nerve microvascular decompression, polyester cotton and use, and develop a preparation method of polyester cotton with an unspecific three-dimensional form, comprising the following steps: curling polyester filaments at a fixed period, and heating and setting between 160°C and 190°C, with a setting time of 30s-60s; unwinding the curled and heat-set polyester filaments; performing a filament separation treatment; cutting the curled and heat-set polyester filaments, with the length of the cut polyester filaments being 1cm to 10cm; agglomerating the separated and cut polyester filaments to form polyester cotton. Through the process of the present invention, that is, by curling and setting the polyester and then unwinding it, after the agglomeration treatment, a polyester cotton with a cotton-like structure can be prepared, which has the characteristics of high fluffiness, high flexibility and high elasticity, can be arbitrarily shaped during clinical procedures, and the shaped polyester cotton is placed between the cranial nerves and microvasculars to achieve isolation of the cranial nerves and microvasculars.

Description

Technical Field

[0001] The invention relates to the technical field of cranial nerve microvascular decompression, and in particular to a preparation method of polyester cotton for cranial nerve microvascular decompression, the polyester cotton and application thereof. Background Art

[0002] Cranial nerves are also called "brain nerves". The human body has 12 pairs of cranial nerves, that is, 24 in total. They are peripheral nerves, and are paired nerves that emanate from the brain. Cranial nerves include the olfactory nerve, optic nerve, oculomotor nerve, trochlear nerve, trigeminal nerve, abducens nerve, facial nerve, auditory nerve, glossopharyngeal nerve, vagus nerve, accessory nerve, and hypoglossal nerve.

[0003] When cranial nerves are compressed by blood vessels, people will experience trigeminal neuralgia, hemifacial spasm, glossopharyngeal neuralgia, masseter spasm, blepharospasm, positional vertigo, Meniere's syndrome, etc. For example, trigeminal neuralgia is a recurring, paroxysmal, severe neuralgia that usually requires conservative or surgical treatment.

[0004] Conservative treatment is to block nerve transmission through mechanical, drug or radiation methods to suppress pain, but it also suppresses the transmission of normal tactile sensation. It cannot cure the disease and will relapse.

[0005] Surgical treatment is to solve nerve pain through clinical craniotomy. Studies have found that symptoms such as cranial neuralgia or spasm are mainly caused by microvascular compression of nerves. Such diseases require the cranial nerves to be separated from the microvascular to avoid direct contact between the microvascular and the cranial nerves. This type of surgery is also called cranial nerve decompression.

[0006] In cranial nerve decompression surgery, the cranial nerves are usually isolated from the microvascular by Teflon (polytetrafluoroethylene) gaskets, Teflon (polytetrafluoroethylene) cotton, polyester gaskets, etc. The defect of Teflon (polytetrafluoroethylene) gaskets is that the Teflon (polytetrafluoroethylene) gaskets are placed between the microvascular and cranial nerves. Because the contact surface area between the gaskets and the cranial nerves and microvascular is small, on the one hand, they become loose and shift due to vibration and other reasons; on the other hand, the Teflon (polytetrafluoroethylene) gaskets are relatively hard. After a long time, the Teflon (polytetrafluoroethylene) gaskets themselves will stimulate the cranial nerves, thereby causing new pain. Teflon (polytetrafluoroethylene) cotton is composed of Teflon (polytetrafluoroethylene) fibers. Teflon (polytetrafluoroethylene) fibers themselves are very elastic and not easy to bend. They are not easy to shape during clinical use, which is not conducive to making them into any shape to fill the unspecified shape space between cranial nerves and microscopic blood vessels. After a long time, the fibers in Teflon (polytetrafluoroethylene) cotton themselves will stimulate cranial nerves and cause new pain. The similarity between polyester gaskets and Teflon (polytetrafluoroethylene) gaskets is that because the contact surface area between the gaskets and cranial nerves and microscopic blood vessels is small, they will be displaced and fall off due to vibration or other factors, resulting in recurrence.

[0007] In view of this, there is an urgent need to develop an insulator between cranial nerves and microvasculars and a preparation method thereof to solve the above problems. Summary of the invention

[0008] The purpose of the present invention is to disclose a preparation method of polyester cotton for cranial nerve microvascular decompression, polyester cotton and its use, and to develop a preparation method of polyester cotton with an unspecified three-dimensional form.

[0009] The first object of the present invention is to develop a method for preparing polyester cotton for cranial nerve microvascular decompression.

[0010] The second object of the present invention is to develop a polyester cotton for cranial nerve microvascular decompression

[0011] The third object of the present invention is to develop a use of polyester cotton.

[0012] In order to achieve the first object of the above invention, the present invention provides a method for preparing polyester cotton for cranial nerve microvascular decompression, comprising the following steps:

[0013] The polyester filaments are curled at a fixed cycle and heated at 160°C to 190°C for 30s to 60s.

[0014] The curled and heat-set polyester filaments are unwound;

[0015] The curled and heat-set polyester filaments are subjected to a filament separation process;

[0016] The curled and heat-set polyester filaments are cut to a length of 1 cm to 10 cm;

[0017] The polyester long fibers after being divided and cut are grouped to form polyester cotton.

[0018] Preferably, the fineness of the polyester filament is d, d=100D~200D, and the number of filaments of the polyester filament is f=(0.2~2)*d.

[0019] Preferably, the period wavelength is 0.5 mm to 3 mm, and the period height is 0.1 mm to 1.5 mm.

[0020] Preferably, the curling is a polyester long fiber weaving process or a slit interlaced curling process.

[0021] Preferably, the loosening is to unweave the woven polyester filaments, or to unweave the slit-interlaced curled polyester filaments.

[0022] Preferably, the filament separation process is to separate the monofilaments constituting the polyester filaments by kneading.

[0023] Preferably, the agglomeration process is to draw, split and entangle polyester filaments of a single length or polyester filaments of different lengths.

[0024] Preferably, the maximum diameter of the polyester cotton is 2 mm to 10 mm.

[0025] Based on the same inventive principle, in order to achieve the above-mentioned second invention purpose, it is prepared by the process described in the first invention.

[0026] Based on the same inventive principle, in order to achieve the above-mentioned third invention purpose, the polyester cotton as described in the second invention creation is used as an insulator in cranial nerve microvascular decompression surgery.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] (1) Through the process of the present invention, that is, by curling and shaping the polyester and then unwinding it, the polyester long fiber has a fixed period of bending. After being subjected to agglomeration, a polyester cotton with a cotton-like structure can be prepared. A polyester cotton with high fluffiness, high flexibility and high elasticity can be prepared. The polyester cotton can be arbitrarily shaped in the clinical process, and polyester cottons of different sizes can be used in combination. The polyester cotton of appropriate size and shape can be quickly selected according to the spatial structure between the cranial nerves and the brain microvascular, and the shaped polyester cotton can be placed between the cranial nerves and the brain microvascular, so as to achieve isolation of the cranial nerves and the brain microvascular, so as to treat the patient's cranial nerve lesions;

[0029] (2) After the polyester filaments are separated, the filaments of the polyester cotton and polyester filaments are in a separated state, that is, the filaments of each bundle of the polyester filaments are separated, making the polyester filaments softer and more cotton-like. It also increases the specific surface area of ​​contact between the polyester cotton and the cranial nerves and microscopic blood vessels, making the contact more secure and less likely to loosen or shift.

[0030] (3) The polyester cotton acts as an insulator between the cranial nerves and the microvascular vessels. The areas pressed by the cranial nerves and the microvascular vessels are in a compressed state, while the uncompressed areas are still fluffy, making the polyester cotton more firmly embedded between the cranial nerves and the microvascular vessels and less likely to loosen or shift. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a schematic diagram of the wavy polyester filament of the present invention;

[0032] Figure 2 This is a schematic diagram of the polyester cotton forming process of the present invention;

[0033] Figure 3 This is a schematic diagram of the polyester cotton morphology of the present invention;

[0034] Figure 4 It is a schematic diagram of the polyester slit staggered curling device of the present invention;

[0035] Figure 5 This is a schematic diagram of the polyester cotton used as an insulator in the present invention.

[0036] Among them, 1. Polyester long fiber; 2. Polyester cotton; 3. Cranial nerves; 4. Microvascular; 5. Top plate; 6. Bottom plate; 7. Top plate vertical knife; 8. Bottom plate vertical knife. DETAILED DESCRIPTION

[0037] The present invention is described in detail below in conjunction with the various embodiments shown in the accompanying drawings, but it should be noted that these embodiments are not limitations of the present invention, and any equivalent transformations or substitutions in functions, methods, or structures made by ordinary technicians in the field based on these embodiments are all within the scope of protection of the present invention.

[0038] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" 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, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0039] Definition of terms:

[0040] Denier: Indicated by the letter d, also known as denier, which is mostly used in chemical fiber filaments. It refers to the weight of 9000m long fiber at the standard moisture regain. For example, when the weight of 9000m long fiber is one gram, it is called 1D. The larger the denier of polyester filament, the thicker the polyester filament; conversely, the smaller the denier of polyester filament, the thinner the polyester filament.

[0041] Number of filaments: Indicated by the letter f, it refers to the number of polyester filaments in a bundle. For example, f=36 means that the number of polyester filaments in a bundle is 36, that is, 36 filaments make up a bundle of polyester filaments.

[0042] Curling at a fixed cycle is to make the polyester filaments wavy in a natural state, so as to improve the fluffiness and elasticity of the polyester cotton. The wavy shape here means that the polyester filaments are bent in the form of waves with a certain wavelength in a natural state.

[0043] Fiber types: According to the different content of titanium dioxide added as matting agent in polyester fiber, polyester fiber can be divided into highly glossy polyester fiber, semi-matt polyester fiber, and fully matt polyester fiber. When the amount of titanium dioxide added in polyester fiber is 0, it is called highly glossy polyester fiber. When the amount of titanium dioxide added in polyester fiber is about 0.3%, it is called semi-matt polyester fiber. When the amount of titanium dioxide added in polyester fiber is about 2.5%, it is called fully matt polyester fiber.

[0044] Fluffiness: refers to the volume cubic inch value occupied by one ounce (30 grams) of polyester cotton under certain conditions. For example, if the space occupied by one ounce of polyester cotton is 800 cubic inches, the fluffiness of the polyester cotton is called 800.

[0045] The specific implementation process of the present invention is described below through multiple embodiments.

[0046] Example 1

[0047] Example 1 discloses a method for preparing polyester cotton for cranial nerve microvascular decompression, comprising the following steps:

[0048] (a) curling the polyester filaments at a fixed cycle, and heating and setting the filaments at 160° C. to 190° C. for 30 s to 60 s; specifically, the fineness of the polyester filaments is d=100D to 200D, and the number of filaments of the polyester filaments is f=(0.2 to 2)*d, such as the polyester filaments can be selected from 100D / 36f, 100D / 72f, 100D / 144f, 150D / 36f, 150D / 72f, 150D / 144f, 150D / 280f, 200D / 36f, 200D / 72f, 200D / 144f, 200D / 280f, 200D / D / 350f, etc., the polyester filament can be selected from one of bright polyester fiber, semi-dull polyester fiber, and full-dull polyester fiber. The "fixed period curling" is to make the polyester filament present a wavy shape in a natural state, so as to improve the fluffiness and elasticity of the polyester cotton. In Example 1, the polyester filament weaving process is adopted for curling. The glass transition temperature of the polyester filament is about 81°C, and it is heated and set at 160°C to 190°C. The preferred setting temperature can be 170°C and 180°C, so that the polyester filament can be set at this temperature after curling. The setting time is controlled between 30s and 60s, and 40s can be selected preferably.

[0049] (b) unwinding the curled and heat-set polyester filaments; specifically, the unwinding in Example 1 refers to unwinding the woven polyester filaments, and the unwinding polyester filaments are wavy in a natural state, and the periodic wavelength L of the wavy shape is 0.5 mm to 3 mm, and the periodic height H is 0.1 mm to 1.5 mm, see Figure 1 .

[0050] (c) subjecting the curled and heat-set polyester filaments to a filament separation treatment; specifically, the filament separation treatment refers to separating the monofilaments constituting the polyester filaments by kneading, that is, separating the monofilaments of the polyester filaments by kneading, thereby making the polyester cotton softer.

[0051] (d) Cutting the curled and heat-set polyester filaments, wherein the length of the cut polyester filaments is 1 cm to 10 cm; specifically, the polyester filaments are cut to prepare for forming polyester cotton balls of different sizes, and the polyester cotton balls may include a single 10 cm polyester filament or may be composed of polyester filaments of different lengths, and a single 10 cm polyester filament may form a polyester cotton ball.

[0052] (e) agglomerating the polyester filaments after splitting and cutting to form polyester cotton; specifically, the agglomeration process in this step is to draw, split, and entangle the polyester filaments of a single length or different lengths, see Figure 2 Drawing refers to drawing the wavy polyester filaments into straight lines, splitting refers to separating the monofilaments of the polyester filaments by rubbing, and winding refers to entangle the monofilaments of the polyester filaments together. The maximum diameter of the polyester cotton finally formed is 2mm to 10mm. Figure 3 .

[0053] It should be noted here that since the shape of polyester cotton is not specific, the diameter value of polyester cotton in different measuring directions is different. The maximum diameter refers to the maximum length of polyester cotton in a certain direction.

[0054] Compared with the prior art, the present invention has the following beneficial effects:

[0055] (1) Through the process of the present invention, that is, by curling and shaping the polyester and then unwinding it, the polyester long fiber has a fixed period of bending. After being subjected to agglomeration, a polyester cotton with a cotton-like structure can be prepared. A polyester cotton with high fluffiness, high flexibility and high elasticity can be prepared. The polyester cotton can be arbitrarily shaped in the clinical process, and polyester cottons of different sizes can be used in combination. The polyester cotton of appropriate shape can be quickly prepared according to the shape space between the cranial nerves and the microvascular. The shaped polyester cotton is placed between the cranial nerves and the microvascular to achieve isolation of the cranial nerves and the microvascular, so as to treat the cranial nerve lesions of the patient;

[0056] (2) After the polyester filaments are separated, the filaments of the polyester cotton and polyester filaments are in a separated state, that is, the filaments of each bundle of the polyester filaments are separated, making the polyester filaments softer and more cotton-like. It also increases the specific surface area of ​​contact between the polyester cotton and the cranial nerves and microscopic blood vessels, making the contact more secure and less likely to loosen or shift.

[0057] (3) The polyester cotton acts as an insulator between the cranial nerves and the microvascular vessels. The areas pressed by the cranial nerves and the microvascular vessels are in a compressed state, while the uncompressed areas are still fluffy, making the polyester cotton more firmly embedded between the cranial nerves and the microvascular vessels and less likely to loosen or shift.

[0058] Example 2

[0059] The difference from Example 1 is that Example 2 adopts a polyester slit interlaced curling process, which Figure 4 The device shown causes the polyester filament to be "curled at a fixed period". The device comprises a top plate 5 and a plurality of top plate vertical knives 7, a bottom plate 6 and a plurality of bottom plate vertical knives 8. A plurality of slits are formed between the top plate vertical knives 7, and a plurality of slits are also formed between the bottom plate vertical knives 8. The polyester filament 1 is arranged between the top plate vertical knives 7 and the bottom plate vertical knives 8. The polyester filament 1 is pressed by the staggered slits formed by the plurality of top plate vertical knives 7 and the plurality of bottom plate vertical knives 8. That is, the plurality of top plate vertical knives 7 are respectively inserted into the slits formed by the bottom plate vertical knives 8, so that the polyester filament 1 is "curled at a fixed period". After the curled polyester filament is heated and set, the loosening is to unweave the polyester filament after the slit staggered curling, that is, after the top plate vertical knives 7 and the bottom plate vertical knives 8 are separated, a wavy polyester filament is formed. The periodic wavelength L of the wavy shape is 0.5mm-3mm, and the periodic height H is 0.1mm-1.5mm. For details, see Figure 1 .

[0060] Example 3

[0061] A method for preparing polyester cotton for cranial nerve microvascular decompression surgery comprises the following steps:

[0062] (a) The polyester filaments are curled at a fixed cycle and heated at 170°C for setting for 40 seconds; specifically, the fineness of the polyester filaments is d=150D, the number of filaments of the polyester filaments is f=144, i.e., 150D / 144f, and the "fixed cycle curling" is to enable the polyester filaments to be wavy in a natural state to improve the fluffiness and elasticity of the polyester cotton. In Example 3, the polyester filaments are curled using a weaving process, the glass transition temperature of the polyester filaments is about 81°C, and the polyester filaments are heated at 170°C for setting, so that the polyester filaments are set at this temperature after curling.

[0063] (b) unwinding the curled and heat-set polyester filaments; specifically, the unwinding in Example 3 refers to unwinding the woven polyester filaments, and the unwinding polyester filaments are wavy in a natural state, and the periodic wavelength of the wavy shape is 1 mm, and the periodic height is 1 mm, see Figure 1 .

[0064] (c) subjecting the curled and heat-set polyester filaments to a filament separation treatment; specifically, the filament separation treatment refers to separating the monofilaments constituting the polyester filaments by kneading, that is, separating the monofilaments of the polyester filaments by kneading, thereby making the polyester cotton softer.

[0065] (d) cutting the curled and heat-set polyester filaments, wherein the length of the cut polyester filaments is 1 cm to 10 cm; specifically, the polyester filaments are cut to prepare for the formation of polyester cotton balls, and the polyester cotton balls may include a single 10 cm polyester filament or may be composed of polyester filaments of different lengths.

[0066] (e) agglomerating the polyester filaments after splitting and cutting to form polyester cotton; specifically, the agglomeration process in this step is to draw, split, and entangle the polyester filaments of a single length or different lengths, see Figure 2 Wire drawing refers to drawing the wavy polyester filaments into straight lines, and wire separation refers to separating the single filaments that make up the polyester filaments by rubbing. The maximum diameter of the polyester cotton finally formed is 10mm. Figure 3 , the same weight of polyester cotton can be made into cotton-like polyester cotton of different sizes during the agglomeration process, and the bulk thickness range can be 600-1500.

[0067] Compared with the prior art, the present invention has the following beneficial effects:

[0068] (1) Through the process of the present invention, that is, by curling and shaping the polyester and then unwinding it, the polyester long fiber has a fixed period of bending. After being subjected to agglomeration, a polyester cotton with a cotton-like structure can be prepared. A polyester cotton with high fluffiness, high flexibility and high elasticity can be prepared. The polyester cotton can be arbitrarily shaped in the clinical process, and polyester cottons of different sizes can be used in combination. The polyester cotton of appropriate shape can be quickly prepared according to the shape space between the cranial nerves and the microvascular. The shaped polyester cotton is placed between the cranial nerves and the microvascular to achieve isolation of the cranial nerves and the microvascular, so as to treat the cranial nerve lesions of the patient;

[0069] (2) After the polyester filaments are separated, the filaments of the polyester cotton and polyester filaments are in a separated state, that is, the filaments of each bundle of the polyester filaments are separated, making the polyester filaments softer and more cotton-like. It also increases the specific surface area of ​​contact between the polyester cotton and the cranial nerves and microscopic blood vessels, making the contact more secure and less likely to loosen or shift.

[0070] (3) The polyester cotton acts as an insulator between the cranial nerves and the microvascular vessels. The areas pressed by the cranial nerves and the microvascular vessels are in a compressed state, while the uncompressed areas are still fluffy, making the polyester cotton more firmly embedded between the cranial nerves and the microvascular vessels and less likely to loosen or shift.

[0071] Example 4

[0072] Based on a large number of experiments, according to the different performance parameters of polyester filaments, Example 4 lists several clinical manifestations of using polyester cotton in cranial nerve microvascular decompression. In the specific clinical process, the polyester cotton must first be soaked in physiological saline, and then the doctor selects polyester cotton of different sizes for shaping according to the spatial shape between the cranial nerves and the microvascular surgery. It can be a single polyester cotton or a combination of polyester cottons of different sizes. The specific examples are shown in Table 1.

[0073] Table 1 Polyester cotton with different performance parameters

[0074]

[0075]

[0076] It should be further explained that no matter how fluffi the polyester cotton is, in specific clinical use, it needs to be soaked in physiological saline first. After soaking, the volume of the polyester cotton will be reduced to a certain extent. At this time, the doctor can shape the polyester cotton arbitrarily. One polyester cotton can be used, such as directly using polyester cotton with a maximum diameter of 20mm, or several polyester cottons of different volumes can be combined for shaping, such as combining polyester cotton with a maximum diameter of 5mm and a maximum diameter of 12mm. After the shaping is completed, the polyester cotton is placed between the cranial nerves and the microscopic blood vessels to act as an insulator.

[0077] Example 5

[0078] Example 5 discloses the polyester cotton prepared by the process of Example 1, Example 2, and Example 3. The specific size and shape thereof refer to Figure 3 .

[0079] The polyester cotton disclosed in this embodiment has the same technical solutions as those in Embodiment 1, Embodiment 2, Embodiment 3, and Embodiment 4. Please refer to Embodiment 1, Embodiment 2, Embodiment 3, and Embodiment 4, and will not be repeated here.

[0080] Example 6

[0081] Example 6 discloses the use of polyester cotton as a spacer in cranial nerve microvascular decompression. Figure 5The polyester cotton 2 is placed as an insulator between the cranial nerve 3 and the microscopic blood vessel 4. The polyester cotton used as an insulator disclosed in this embodiment has the same technical solution as that in Example 5. Please refer to Example 5 and will not be repeated here.

Claims

1. A method for preparing polyester cotton for cranial nerve microvascular decompression, characterized in that: The following steps are involved: The polyester filaments are curled at a fixed cycle and heated at 160°C to 190°C for 30s to 60s. The curled and heat-set polyester filaments are unwound; The curled and heat-set polyester filaments are subjected to a filament separation process, so that the individual filaments of the polyester filaments are separated by kneading; The curled and heat-set polyester filaments are cut to a length of 1 cm to 10 cm; The polyester filaments after splitting and cutting are subjected to agglomeration to form polyester cotton. The agglomeration process is to draw, split and entangle the polyester filaments of a single length or different lengths. Drawing refers to drawing the wavy polyester filaments into straight lines, splitting refers to separating the monofilaments of the polyester filaments from each other by rubbing, and entanglement refers to entangle the monofilament-separated polyester filaments together. The maximum diameter of the polyester cotton finally formed by the agglomeration is 2mm~10mm; The fineness of the polyester filament is d, d=100D~200D, and the number of filaments of the polyester filament is f=(0.2~2)*d; The crimping is a polyester long fiber weaving process; The loosening is to unweave the woven polyester filaments; The period wavelength is 0.5 mm to 3 mm, and the period height is 0.1 mm to 1.5 mm; The bulkiness of the polyester cotton is 600-1500.

2. A method for preparing polyester cotton for cranial nerve microvascular decompression, characterized in that: The following steps are involved: The polyester filaments are curled at a fixed cycle and heated at 160°C to 190°C for 30s to 60s. The curled and heat-set polyester filaments are unwound; The curled and heat-set polyester filaments are subjected to a filament separation process, so that the individual filaments of the polyester filaments are separated by kneading; The curled and heat-set polyester filaments are cut to a length of 1 cm to 10 cm; The polyester filaments after splitting and cutting are subjected to agglomeration to form polyester cotton. The agglomeration process is to draw, split and entangle the polyester filaments of a single length or different lengths. Drawing refers to drawing the wavy polyester filaments into straight lines, splitting refers to separating the monofilaments of the polyester filaments from each other by rubbing, and entanglement refers to entangle the monofilament-separated polyester filaments together. The maximum diameter of the polyester cotton finally formed by the agglomeration is 2mm~10mm; The fineness of the polyester filament is d, d=100D~200D, and the number of filaments of the polyester filament is f=(0.2~2)*d; The curling is a slit staggered curling process; The loosening is to unweave the polyester filaments after the slit staggered curling; The period wavelength is 0.5 mm to 3 mm, and the period height is 0.1 mm to 1.5 mm; The bulkiness of the polyester cotton is 600-1500.

3. Polyester cotton for cranial nerve microvascular decompression, characterized in that: It is prepared by the process described in claim 1 or 2.

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