Friction coefficient test and surface lubricity treatment of catheter

Abstract: clinically, the catheter needs to be contacted with the body tissue for a long or short time Each time the catheter is inserted or pulled out, the patient will have different degrees of burning pain, which is easy to cause corresponding mucosal damage, even tissue inflammation This is mainly due to the large friction coefficient between the surface material of the catheter and the body tissue This paper will introduce the measurement of the surface friction coefficient of the catheter with Labthink blue light friction coefficient instrument, and further elaborate the importance of the measurement of the surface friction coefficient of the catheter and the treatment method of the surface lubrication Key words: catheter, medical catheter, friction coefficient and smoothness Author: Jinan Languang Electromechanical Technology Co., Ltd medical catheter is a general term for connecting internal and external lumen products of human body It is widely used in clinical fields such as drug administration, perfusion, drainage, etc through the forms of venous catheter, intubation, catheter, etc Among them, the catheter is an indispensable medical device in clinical application Its emergence makes some traditional diagnosis and treatment methods with high risk and complicated operation find an ideal alternative method, and then improves the medical level and the rehabilitation of the patients' physical and physiological functions The catheter is made of natural rubber, silicone rubber or polyvinyl chloride (PVC) It can be inserted into the bladder through the urethra to drain urine After the catheter is inserted into the bladder, there is an air bag near the head of the catheter to fix the catheter and leave it in the bladder, which is not easy to get out, and the catheter is connected with the urine bag to collect urine Clinically, the catheter needs long-term or short-term contact with the body tissue Each time when inserting or pulling out the tissue, the patient will have different degrees of burning pain, which is easy to cause corresponding mucosal damage, even tissue inflammation This is mainly due to the larger friction coefficient of catheter The friction coefficient is mainly used to guide the friction coefficient between the surface material of the catheter and the patient's matrix tissue At present, there is no clear standard about how to test its indicators Labthink Languang laboratory with many years of testing experience and strong technical strength, through its own product mxd-02 friction coefficient instrument for special restructuring, can be professional for medical catheter surface friction coefficient instrument testing Test methods are described in detail below (I) test location: test instrument of Languang packaging safety test center: mxd-02 friction coefficient instrument test preparation: 36 catheters made of latex, PVC and pur respectively Take the latex catheter as an example, each 12 catheters were divided into three groups, the * group was the test control group, the second group was treated with PVP lubrication, the third group was coated with paraffin oil, six catheters in each group were immersed in water for 30s, the other six catheters were immersed in water for 24h PVC and pur catheters were used in the same way Test method: take two samples of the test control group immersed in water for 30s, fix them on the V-groove plate through the ① sample clamping device, and inject water into the ③ water storage tank until the samples are completely immersed Put 200g ④ standard sliding block lightly on the top of ⑤ sample, drag the sliding block by ⑥ sensor connecting rod to move at the speed of 100mm / min in the direction indicated by the arrow, then the dynamic friction coefficient can be measured, Zui finally takes the average friction coefficient value of 6 samples In the same way, the friction coefficients of the other two materials under different soaking time were measured Equipment introduction: mxd-02 friction coefficient instrument is a professional intelligent friction coefficient instrument independently developed and produced by Labthink Languang The equipment conforms to GB, ASTM and ISO standards, and can be used to measure the static and dynamic friction coefficients of plastic film and sheet, rubber, paper, cardboard, woven bag, fabric style, conveyor belt, wood, coating, brake pad and other materials when sliding Mxd-02 integrated PVC operation panel, micro printer and LCD screen which can display test data, results and curves enable users to conduct non computerized test The professional test software has an intuitive operation interface, real-time data display and composition functions, supports the export of test results in Excel format, and can carry out scientific statistical analysis and processing of single or group test results, historical data comparison and group test curve superposition analysis The powerful data analysis function can also help the user to carry out quantitative discrete analysis of test results and judge the slip and stick state by preset shock coefficient Test results: (2) in clinical treatment, the catheter needs long-term or short-term contact with the body tissue Each time the catheter is inserted or pulled out, the patient will have different degrees of burning pain, which is easy to cause corresponding mucosal damage, even tissue inflammation This is mainly due to the large friction coefficient between the surface material of the catheter and the body tissue For this reason, researchers and medical staff have used a variety of means to lubricate the surface of the catheter, in order to reduce the medical pain of patients 1、 Paraffin oil or complex iodine external paraffin oil is a kind of mineral oil A certain amount of it is dipped in cotton ball and applied on the surface of catheter, so that it has a good lubricating effect However, in clinical application, there are several risks in this method: 1 Cotton ball application increases the probability of bacterial infection; 2 Paraffin oil is not absorbed by the mucosa, such as inadvertently entering the trachea or infiltrating into the tissue, which is easy to cause other diseases Therefore, this lubrication method is gradually eliminated by the industry Complex iodine coating is a new attempt and research in recent years The complex iodine is iodophor, which is composed of iodine and non-ionic surfactant It is a non-toxic and tasteless traditional bactericide At the same time, it is also a kind of water-soluble reagent, with strong permeability of mucous membrane, which can be used as a catheter lubricant with bactericidal effect, prevent bacteria from being carried into the bladder through the catheter, and reduce the probability of urinary tract infection This external coating method is simple and easy to use with low cost, but there are two common disadvantages: 1 It is unable to fully lubricate every part of the catheter; 2 In the process of intubation, the friction between the lubricant and the urethra is continuous, and the friction damage between the catheter and the urethra is increased Two Silicone gel coated silicone catheter is mainly adhered to the surface of the catheter with a curable silicone elastomer through impregnation, spray or brush, forming a silicone elastomer lubricant film The results show that the effect of repeated impregnation is good, which can effectively control the total thickness of the coating and the uniformity of each part When the coating reaches the specified thickness, the tube is cured at room temperature of 25 ℃ and 10-50% RH for 16 hours, and the lubricating film achieves the desired characteristics within seven days This kind of catheter with silica gel coating can reduce the friction and damage between the catheter and the body tissue during insertion, and reduce the risk of infection 3、 In this method, the stable polymer solution is first coated on the surface of the catheter After drying, the hydrophilic polymer which does not react with it is bonded on the stable polymer coating as the surface layer After drying again, the solid water-soluble lubricant coating can be formed Cellulose esters with strong adhesion should be selected as the base material of polymer solution to increase the firmness of coating and conduit surface The choice of hydrophilic polymer is related to the lubrication effect of the coating As a kind of water-soluble polymer, polyvinylpyrrolidone (PVP) has been proved to have good physiological compatibility and solubility by clinical application for many years, and it is suitable for the lubrication layer of catheter In dry condition, the catheter with water-soluble lubricating coating is no different from the ordinary catheter When the coating contacts with the aqueous liquid, the PVP molecule absorbs water rapidly to form hydrophilic gel layer and will not fall off, and it will play a full lubrication role when intubation It is proved by experiments that the friction coefficient of the catheter surface decreases with the increase of PVP coating content This is due to the increase of PVP content, the more PVP molecules are entangled with the surface of the catheter, the thicker the hydrogel layer formed after water absorption, the smaller the friction area between the pipe substrate and the external tissue, and the friction coefficient decreases correspondingly With this method, not only the friction between catheter and urethra is reduced to a large extent, but also the patients' pain and infection are reduced, and the safety is greatly improved In the process of PVP coating, the water content of PVP will have a certain impact on the lubrication effect Due to its own characteristics and moisture absorption, the water content of PVP raw materials is 3% - 5% It is verified by industry experts that when the water content is more than 1%, the coating is prone to uneven phenomenon, resulting in poor lubrication Therefore, it is suggested that PVP raw materials should be dried before coating to control the water content in a reasonable range Languang packaging safety testing center also tested the friction coefficient of three kinds of catheter after lubrication The test results show that PVP is suitable for both lubrication effect and durability The effect of lubricating treatment on the surface of the catheter is better than that of paraffin oil The catheter used in this method only needs to be immersed in sterile water The hydrophilic gel layer quickly forms abnormal lubrication, which greatly reduces the friction coefficient between the catheter and the body tissue and the pain of the intubation of the patient, and has no adverse reactions Therefore, the method can be regarded as the ideal side for the lubrication treatment of the catheter surface Law Copyright notice: the copyright of this article is Jinan Languang Electromechanical Technology Co., Ltd It is forbidden 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