Pulsed Electron Avalanche Knife: Intraocular Microsurg.

描述：这项应用提出了一种高精度、低成本的基于液体介质中脉冲等离子体放电的电切割仪器的进一步发展。应用包括无牵引力去除玻璃体视网膜膜，以避免机械器械施加的力对潜在视网膜造成机械损伤的风险。该装置还将用于囊膜切开术，在撕囊过程中不会有破裂的风险，也不会对索状纤维施加机械应力。此外，囊膜切开术仅适用于囊膜视觉性差或瞳孔偏小的患者。将探索在非穿透性小梁切除术和其他眼科和非眼科显微外科手术中的应用。该设备还具有凝聚、电粘合和注射操作能力。 在过去的两年里，他们开发了一种名为脉冲电子雪崩刀(PEAK)的设备，用于切割软组织，通过尖端电极施加100 ns长的高压脉冲。该仪器能够对液体介质中的软组织进行精确的解剖，但由于以下因素，该仪器存在一定的局限性：(1)单个脉冲产生一系列穿孔，这些穿孔并不总是合并成连续的切割。(2)由于空化气泡的球状几何形状，切割深度和宽度是相关联的。(3)仪器没有解剖巩膜、角膜等更多的纤维组织。(4)尖端微电极不能凝固组织。 本提案中提出了该仪器的一个更先进的版本，它克服了以前的限制：(1)使用细长电极用其刃口而不是用尖端切割组织；(2)施加一个脉冲串，而不是单个亚微秒脉冲，从而避免强烈的气蚀；(3)将相互作用机制从机械破碎改变为快速汽化和电离，从而扩大了对纤维组织的适用范围；(4)由于细长电极暴露的面积足够大，因此可以实现凝固能力。 上述建议的实施将导致最精确和最广泛适用的无牵引力手术装置的产生，这不仅将极大地提高当前外科手术的精确度和安全性，而且可能导致新的显微外科技术的发展。这种设备，允许“冷”解剖、凝固、组织的电胶操作和微注射，还将包括照明、冲洗和抽吸。它可以小型化到25英寸大小，并可以集成到内窥镜中。该系统成本低、体积小，再加上高精度、可靠性和通用性，应能在操作实践中得到广泛接受。

DESCRIPTION: This application proposes the further advancement of a highly precise low cost electrical cutting instrument based on pulsed plasma-mediated discharges in a liquid medium. Applications include traction-free removal of vitreoretinal membranes to avoid the risk of mechanical damage to the underlying retina associated with forces exerted by mechanical instruments. This device will also be applied for capsulotomy with no risk of rupture and mechanical stress to zonular fibers exerted during capsulorhexis. Additionally, capsulotomies will be created simply in eyes with poor visualization of the capsule, or with a miotic pupil. Applications to non-penetrating trabeculectomy and other ophthalmic and non-ophthalmic microsurgical procedures will be explored. This device also has coagulation, electro-adhesion and injection operating capabilities. During the last two years they have developed a device called Pulsed Electron Avalanche Knife (PEAK) for cutting soft tissue with 100 ns-long pulses of high voltage applied via a pointed electrode. This instrument was capable of precise dissection of soft tissue in liquid media, but certain limitations were found due to the following factors: (1) Individual pulses produce a series of perforations, which did not always merge into a continuous cut. (2) Depth and width of the cut were linked due to spherical geometry of cavitation bubbles. (3) The instrument did not dissect more fibrotic tissue such as sclera and cornea. (4) Pointed microelectrodes were not able to coagulate tissue. A much more advanced version of the instrument is presented in this proposal, which overcomes those previous limitations by (1) Application of an elongated electrode dissecting tissue with its cutting edges rather than with its apex; (2) Applying a burst of pulses instead of a single sub-microsecond pulse thus avoiding strong cavitation (3) Changing the mechanism of interaction from mechanical fragmentation to rapid vaporization and ionization will extend applicability to fibrous tissues; (4) A coagulation capability that can be achieved due to sufficiently large exposed area of elongated electrode. Implementation of the described proposal should result in creation of the most precise and broadly-applicable tractionless surgical device that will not only strongly improve precision and safety of the current surgical procedures but may lead to development of new microsurgical techniques. This device, allowing for "cold" dissection, coagulation, electro-adhesive manipulation of tissue and microinjection will also include illumination, irrigation and suction. It is miniaturizable to a 25 gauge size and can be incorporated into an endoscope. The low cost and small size of this system combined with high precision, reliability and versatility should allow for a widespread acceptance into operating practice.