This work is focussed on the ideation, design and development of two novel prototype electrosurgical devices for use in minimally invasive and non-invasive surgery. The two devices presented here are the first devices in the world to deliver both microwave energy at a frequency of 5.8GHz and bipolar RF energy at a frequency of 400 kHz from an arrangement of miniature energy delivering scissors, where the blades are blunt to prevent tissue damage when inside organs, but become ‘sharp’ cutting tools when bipolar RF energy is applied to the blades.
The first device was developed to perform laparoscopic or key-hole surgery, where an incision is made in the abdomen, and the second device was designed to perform endoscopic surgery, where the device is inserted into one of the natural orifices and is thus scarless.
This thesis describes the design and development and pre-clinical evaluation of the two devices. It includes an investigation into a number of possible radiating blade structures, mechanical actuation of the blades and means of controllably rotating the flexible device when inserted inside the working channel of an endoscope with an internal diameter of 3.2mm. This work involved applying a range of mechanical and electrical design techniques and close interaction with a cohort of gastroenterologists and surgeons in the UK, USA Germany, Australia and Japan.
Both prototype designs were evaluated for clinical efficacy using representative ex-vivo and in-vivo tissue models at Northwick Park Institute for Medical Research (NPIMR), Harrow, UK, at a tissue testing facility linked to Florida Hospital and at a similar tissue testing facility in Boston USA, where positive feedback was obtained from a cohort of world leading gastroenterologists, including Professor Rob Hawes of Florida Hospital, Oliver Pech of Regensburg Hospital in Germany, Bronte Holt of St. Vincent's Hospital Melbourne, Australia, Amyn Haji of King’s College Hospital, UK, Kazuki Sumiyama from The Jikei University School of Medicine, Tokyo, Japan, and Zacharias Tsiamoulos from East Kent Hospital, Kent, UK.