Surface Potential Simulation and Electrode Design for in-Ear EEG Measurement.

The need for everyday-real-time EEG sensing has resulted in the development of minimalistic and discreet wearable EEG measuring devices. A front runner in this race is in-ear worn device. However, the position of the ear as well as its restricted accessibility poses certain challenges in the design of such devices - from the type of materials used to the placement of electrodes. These choices are important as they will determine the quality of the EEG signal available and in turn the accuracy of the application. We therefore create a simulation model of the human ear, allowing us to understand the impact of these choices on our design of an In-Ear EEG wearable. We first study the signal acquisition characteristics of a proposed gold-plated electrode against two other state-of-the-art electrode materials for in-ear EEG data collection. We further validate this electrode choice by fabricating a personalized silicone-based earpiece and collecting in-situ EEG data. This work explores the properties of using gold plated electrodes in capturing in-ear EEG signals enabling unobtrusive collection of the brain physiology data in real world setting.

Embryonal Rhabdomyosarcoma of External Ear - A Rare Case Report.

The Rationale: Rhabdomyosarcoma (RMS) is an uncommon tumour which presents at a wide variety of different head and neck sites. They are highly aggressive malignant mesenchymatous soft tissue sarcomas. Their occurrence in the outer ear is extremely rare. Patient Concerns: A 17-year-old female patient reported with a chief complaint of steady increase in growth over the left ear since 6 months, which is not associated with pain and ulceration. Diagnosis: Edge biopsy sections of the swelling over the left pinna and immunohistochemistry records of cells show MYODI positive confirming as Embryonal RMS. Treatment: Left auriculectomy and supra-omohyoid neck dissection with level V lymph node was performed. Outcomes: Uneventful postoperative healing in the resected site was elicited in the follow-up period of 1 year with no recurrence. Take-away Lessons: External ear RMS is extremely rare. Careful clinical, radiological and histopathological evaluation are essential for prompt definitive diagnosis and for successful management.