可攜式肌肉注射裝置之可行性分析與設計

Abstract

針劑注射為臨床常用的給藥手段之一。其中，肌肉注射是某些特定藥品，如緊急狀況下常用的阿托品(atropine)。而無針注射器改善了針劑注射的諸多缺點，並利於緊急救助人員訓練及使用。 本文重點旨在設計可攜式無針肌肉注射裝置。由藥理學與護理學，訂立出注射深度在皮下25 mm的位置。同時，以流體力學與市售產品Medi-jector VISIONR為基礎，建立了一個噴流速度與活塞壓力的模型，並以量測該產品的噴口速度與動力大小驗證其準確性。確立該模型可以適用於調整裝置動力源設計。礙於人體組織得難以取得，以豬隻的生物體組織作為測試體，並選用MTS Tytron 250試驗機量測生物體的抗穿刺特性。由於人類的皮膚和脂肪層厚度皆比豬隻小。並在假設豬隻的脂肪層與肌肉層各項性質與人類接近下，將人類皮膚、豬隻脂肪與肌肉層參數：包括人類皮膚與豬隻脂肪提供的摩擦力，及豬隻肌肉層所需的穿透應力，並代入人體的幾何參數，藉此得以估算欲達成人體肌肉注射所需要的穿透應力為71 MPa，換算噴流速度規格為376.83 m/s。 在獲得上述兩項規格後，訂立出三個模組的概念設計，分別是：動力源模組、活塞與藥筴模組、噴口模組。比較目前多項市售產品與文獻，由四種動力源中選擇氣壓式作為動力種類，並選定以12 G氣瓶(可提供12.41 MPa的壓力)作為動力源。並且以市售產品VISIONR的噴口改裝作為肌肉注射裝置用(口徑176 □m)。同時，以增加活塞與氣壓源間面積至少8.28倍的方式，使12 G氣瓶可以適用於提供噴流速度至所需的規格。最後，配合藥物常見包裝訂定藥筴容量為3 ml。並完成整體注射裝置的細部尺寸訂定。

Syringe injection is one of the conventional administration methods. In which, intramuscular injection is particular to some emergency medicines, for example, atropine. The needle-free injection improved many drawbacks and benefit to the EMT members in training and their usage. The focus of this thesis is the design of a portable needle-free intramuscular injection device. According to pharmacology and nursing, the specification of the injection depth is set as 25 mm underneath the skin surface. Meanwhile, according to the fluid mechanics theory and the commercial product Medi-jector VISIONR, a model of the relation between piston pressure and outlet injection velocity is constructed and its accuracy is verified by measuring the outlet velocity and the output power of VISIONR. In respect of the difficulty of obtaining the human tissue, the test body of the anti-puncture property experiment is resorted to the porcine tissue. In order for investigating the anti-puncture property of the porcine tissue, the MTS Tytron 250 test machine is chosen to execute the experiment. Since the thickness of human skin and subcutaneous fat are lower than porcine tissue; and under the assumption that all the subcutaneous fat and muscle property of porcine are similar to human, including the penetration stress and the friction force during penetration. The human skin property, the porcine subcutaneous fat and muscle property are subjected to a human tissue geometry model for estimating the penetration stress of human body. Under the estimation, the penetration stress of human body is 71 MPa, which can be transformed into velocity form, 376.83 m/s, and the specification of the injection velocity is developed as 376.83 m/s. Three modules of the portable needle-free intramuscular injection device are proposed after the specifications are developed: power unit module, cartridge and piston module and nozzle module. The pneumatic power source is chosen as the power unit module after the comparison of four types of the power. In which, the 12 gauge CO2 gas cylinder is chosen in the device. The nozzle from the commercial product VISIONR, which is 176 mm in nozzle diameter, is chosen as the nozzle of the device. For reaching the injection velocity of specification, 376.83 m/s, the area between the piston and the gas cylinder is set as 8.28 times of the piston. As the result, the 12 G gas cylinder can afford to push the stream in the specification velocity. The volume of cartridge is set as 3 ml in compliance with the ampoule of the conventional package of medicines. Eventually, the detail of the device is proposed and the design of the needle-free intramuscular injection device is finished.