Taran Tatla

Spatial Compounding Algorithm for Speckle Reduction of Dynamic Focus OCT Images

Optical coherence tomography is capable of imaging the microstructures within tissues. To preserve the transverse resolution at all imaging depths, we implement a dynamic focusing scheme. To improve the quality of images further, a simple speckle reduction scheme is employed which uses the vibration introduced by the translation stage used for axial scanning. A spatial compounding technique is developed based on co-registration followed by an averaging algorithm. We conclude that the degree of speckle reduction achieved is worth the expense of more complicated processing required.

Dual instrument for in vivo and ex vivo OCT imaging in an ENT department

A dual instrument is assembled to investigate the usefulness of optical coherence tomography (OCT) imaging in an ear, nose and throat (ENT) department. Instrument 1 is dedicated to in vivo laryngeal investigation, based on an endoscope probe head assembled by compounding a miniature transversal flying spot scanning probe with a commercial fiber bundle endoscope. This dual probe head is used to implement a dual channel nasolaryngeal endoscopy-OCT system. The two probe heads are used to provide simultaneously OCT cross section images and en face fiber bundle endoscopic images. Instrument 2 is dedicated to either in vivo imaging of accessible surface skin and mucosal lesions of the scalp, face, neck and oral cavity or ex vivo imaging of the same excised tissues, based on a single OCT channel. This uses a better interface optics in a hand held probe. The two instruments share sequentially, the swept source at 1300 nm, the photo-detector unit and the imaging PC. An aiming red laser is permanently connected to the two instruments. This projects visible light collinearly with the 1300 nm beam and allows pixel correspondence between the en face endoscopy image and the cross section OCT image in Instrument 1, as well as surface guidance in Instrument 2 for the operator. The dual channel instrument was initially tested on phantom models and then on patients with suspect laryngeal lesions in a busy ENT practice. This feasibility study demonstrates the OCT potential of the dual imaging instrument as a useful tool in the testing and translation of OCT technology from the lab to the clinic. Instrument 1 is under investigation as a possible endoscopic screening tool for early laryngeal cancer. Larger size and better quality cross-section OCT images produced by Instrument 2 provide a reference base for comparison and continuing research on imaging freshly excised tissue, as well as in vivo interrogation of more superficial skin and mucosal lesions in the head and neck patient.

Multidisciplinary difficult airway simulation training: two year evaluation and validation of a novel training approach at a District General Hospital based in the UK

Our objective was to devise and assess a multidisciplinary simulated course in training junior doctors for possible difficult airway scenarios. The authors have run a multi-disciplinary difficult airway simulation that was designed to simulate the stresses and complications of a live situation. The course comprised of six to eight difficult airway simulations (using a Laerdal SimMan2 mannequin remote controlled by a “driver”) with two teams moving through the simulations over half a day. The simulation lasted 20xa0min and was followed by 40xa0min of in-depth structured facilitated debrief. The course was set in the anaesthetic room of a district general hospital theatre. Seventy-eight candidates (28 anaesthetic trainees, 18 ENT trainees, 19 theatre nurses and 13 operating theatre practitioners) attended this course over 6 training days set over 2xa0years. The main outcome measures of candidate feedback scored for eight questions on a 1–6 Likert scale. From the results, Audit of Trust inpatient airway fatalities revealed three deaths in 2xa0years leading up to the introduction of the simulation course. Re-audit of the subsequent 2xa0years, during which time the course was running, has shown no airway fatalities. A 100xa0% candidate feedback response rate was obtained. Delegates gave an average score of 4.8 to the simulator replicating the stress of ‘live’ situations; 5.5 to the simulator addressing training needs; 5.6 to the course improving clinical knowledge, teamwork, leadership and non-technical skills. In our conclusions, successful management of a difficult airway situation requires rapid evaluation, effective communication, strong leadership and teamwork, as well as knowledge of local environment and equipment. The results show that candidates felt an improvement in clinical knowledge, teamwork, leadership and non-technical skills, as well as the mutual understanding and respect between related medical and non-medical team members. In addition, audit of airway mortality showed a Trust-wide reduction in inpatient airway related mortality following the course. The results emphatically demonstrate the universal success of this multi-disciplinary training method for all team members, regardless of hierarchical position or background.

Ex vivo optical coherence tomography imaging of larynx tissues using a forward-viewing resonant fiber-optic scanning endoscope

A miniature endoscope probe for forward viewing in a 50 kHz swept source optical coherence tomography (SS-OCT) configuration was developed. The work presented here is an intermediate step in our research towards in vivo endoscopic laryngeal cancer screening. The endoscope probe consists of a miniature tubular lead zirconate titanate (PZT) actuator, a single mode fiber (SMF) cantilever and a GRIN lens, with a diameter of 2.4 mm. The outer surface of the PZT actuator is divided into four quadrants that form two pairs of orthogonal electrodes (X and Y). When sinusoidal waves of opposite polarities are applied to one electrode pair, the PZT tube bends transversally with respect to the two corresponding quadrants, and the fiber optic cantilever is displaced perpendicular to the PZT tube. The cantilevers resonant frequency was found experimentally as 47.03 Hz. With the GRIN lens used, a lateral resolution of ~ 13 μm is expected. 2D en face spiral scanning pattern is achieved by adjusting the phase between the pairs of X and Y electrodes drive close to 90 degrees. Furthermore, we demonstrate the imaging capability of the probe by obtaining B-scan images of diseased larynx tissue and compare them with those obtained in a 1310 nm SS-OCT classical non-endoscopic system.

Extramedullary plasmacytoma of the tongue base.

Despite its rarity, extramedullary plasmacytoma should be considered in the differential diagnosis of a base of tongue mass.

How we do it: Changes in thyroid and salivary gland surgery since 1989: who's doing it and what are they doing?

•u2002The aim of this study was to identify changes in the provision of parotid, submandibular and thyroid gland surgery between surgical specialties since 1989, as well as changes in surgical practice.

Endoscopic CO2 Laser Excision of a Ruptured Laryngocele: A novel "blue-dye" technique to assist dissection and avoid recurrent laryngeal nerve injury.

A laryngocele is a rare benign dilatation of the laryngeal saccule and may have internal, external or combined components presenting a therapeutic dilemma to otolaryngologists. An external approach (by laryngofissure or lateral thyroidotomy) is favoured for larger and external laryngoceles. Advances in surgical technology have enabled internal laryngoceles to be resected endoscopically, utilising the CO2 laser. Magnification and precise laser dissection through a minimally invasive approach allows for safer surgery and quicker recovery. The success of this procedure depends upon early and clear delineation of the sac and its neckwithin the ventricle, identifying the correct dissection plane between the sac and surrounding tissue. The differentiation between laryngocele, normal supraglottic mucosa, surrounding muscle fascia and the intralaryngeal component of the recurrent laryngeal nerve can present a challenge to the surgeon.

Delayed presentation of an undiscovered nasopharyngeal foreign body.

Suspected paediatric aerodigestive tract foreign body (FB) ingestion or aspiration is a commonly encountered emergency. Management may require a general anaesthetic for retrieval with bronchoscopy, laryngoscopy and oesophagoscopy, each dependent on the history and investigations of the case in question. We describe the case of a foreign body, which was missed in the nasopharynx for more than 3u2005years and also discuss how pressures on National Health Service (NHS) referral and follow-up patterns may have altered the time course of the eventual discovery.

Inadvertent insertion of hearing aid impression material into the middle ear: Case report and implications for future community hearing services

INTRODUCTION The creation of ear moulds for hearing aids is generally considered a safe and routine procedure for trained professionals. In the literature there are reports of otological complications caused by hearing aid mould impression material in the middle ear cavity but such complications are considered rare. PRESENTATION OF CASE We present the case of a patient in whom impression material entered the middle ear through a perforation of the tympanic membrane during the process of making a hearing aid mould and review how this was managed. DISCUSSION We discuss how many aspects of the British Society of Audiology guidelines were not followed during this procedure and make recommendations as to how independent community practitioners need to be closely supervised with regular review to minimise the risks of such complications. CONCLUSION Our report demonstrates how a serious otological complication from the creation of a hearing aid impression in a community based private hearing clinic was managed. The reporting of such complications is rare but the incidence is likely to be much higher than the literature would suggest. We recommend and advise how these adverse incidents may be minimised and managed through competency reviews and formal referral links from community centres to hospital otolaryngology/audiology departments.

Toothache: an unlikely presentation of secondary breast malignancy.

An 81-year-old female presented to the maxillo-facial department with a 6-month history of left-sided toothache and upper lip and cheek numbness. She had previously undergone a right mastectomy for breast adenocarcinoma, followed 6 years later by left mastectomy with pneumonectomy for contralateral breast and lung metastases. Following buccal biopsies and MRI of the head and neck, the patient was referred to our head and neck team. The MRI showed a large left maxillary sinus mass and transnasal endoscopic biopsies under general anaesthesia of this confirmed distant breast carcinoma metastasis. The patient was discussed at the Head and Neck Multidisciplinary Team meeting. Further surgical resection was not thought appropriate and the patient has subsequently undergone curative dose radiotherapy to the face. She remains alive with symptom control 8 months following this presentation.