Reusable Bipolar Vessel Sealing Device with a Uniform Pressure Profile

Abstract

Bipolar electrosurgical vessel sealing is commonly used in human and veterinary medicine. This method of vessel sealing is often preferred over traditional suturing or clipping of blood vessels because it comes with the advantages of reducing intraoperative blood loss and operation time. Most bipolar vessel sealers are disposable. The high costs of the devices often lead to unrightful reuse in LMICs, increasing the risk of postoperative infection. Next to that, many existing vessel sealing devices operate using a scissor-like clamp that exerts a larger clamping pressure at the proximal end than at the distal end of the clamp. Studies have shown that an unevenly distributed clamping pressure negatively affects the burst pressure of the seal [1][2][3]. The aim of this thesis is to redesign the conventional bipolar vessel sealer to a reusable version that exerts a uniformly distributed pressure across the clamping surface.
A design goal and a set of design requirements were constructed to clarify the objectives. This was followed by a creative design process which was executed to generate solutions for the problems of disposability and uneven pressure distribution. The concept for reusability was verified by mechanical analysis of forces and by rapid prototyping. For the pressure distribution, three concepts were made and tested for performance during an experiment. A redesign of the conventional bipolar vessel sealer was made in CAD containing the innovations for reusability and the pressure distribution mechanism that performed best.
A mechanism has been designed that allows the closing of the upper jaw to be actuated by forward motion of the blade. This eliminates the need for a separate jaw actuator hence promotes cleanability and reusability. The pressure distribution experiment demonstrated which mechanism performed the best. These innovations together with other design considerations have been incorporated into a CAD model of the redesigned bipolar vessel sealer.
The design goal has been met successfully. All design requirements have been met except for one. The removability of the blade lacks in the redesign because it was hindered by other innovations. A list of recommendations has been made to highlight potential future opportunities and shortcomings.