An autonomous surgical robot for drilling a cochleostomy: preliminary porcine trial.

OBJECTIVE: To produce an autonomous drilling robot capable of performing a bony cochleostomy whilst minimising the damage to the underlying cochlear endosteum. DESIGN: In this laboratory based study, a robotic drill was designed to measure the changes in force and torque experienced by the tool point during the drilling process. This information is used to predict the point of breakthrough and stop the drill prior to damaging the underlying endosteal membrane. SETTING: Aston University. PARTICIPANTS: Five porcine cochleas. MAIN OUTCOMES MEASURES: An assessment was made of whether a successful bony cochleostomy was performed, the integrity of endosteal membrane was then assessed. RESULTS: The autonomous surgical robotic drill successfully performed a bony cochleostomy and stopped without damaging the endosteal membrane in all five cases. CONCLUSIONS: The autonomous surgical robotic drill can perform a cochleostomy whilst minimising the trauma to the endosteal membrane. The system allows information about the state of the drilling process to be derived using force and torque data from the tool point. This information can be used to effectively predict drill breakthrough and implement a control strategy to minimise drill penetration beyond the far surface.

A surgical robot for cochleostomy.

In this paper a robotic micro-drilling technique for surgery is described. The device has been deployed in cochleostomy, a precise micro-surgical procedure where the critical stage of controlling penetration of the outer bone tissue of the cochlea is achieved without penetration of the endosteal membrane at the medial surface. The significance of the work is that the device navigates by using transients of the reactive drilling forces to discriminate cutting conditions, state of tissue and the detection of the medial surface before drill break-out occurs. This is the first autonomous surgical robot to use this technique in real-time as a navigation function in the operating room and unlike other fully autonomous surgical robotic processes it is carried out without the use pre-operative data to control the motion of the tool. To control tool points in flexible tissues requires self-referencing to the tissue position in real time. There is also the need to discriminate deflections of the tissue, tissue interface, involuntary patients/tissue movement and indeed movement induced by the drill itself, which require different strategies to be selected for control. As a result of the design of the final system, the break-out process of the drill can either controlled to the required level of protrusion through the flexible interface or can be avoided altogether, with the drill bit at the medial surface. This enables, for the first time, the control of fine penetration with such great precision.

Tracheal stenting: a better method of dealing with airway obstruction due to thyroid malignancies than tracheostomy.

Tracheostomy remains the primary method of treatment of acute airway obstruction due to malignant invasion and compression of the trachea. However, the development of tracheal stents has provided an alternative effective treatment modality. This case report and literature review highlights the benefits of intra-luminal stenting, including resolution of distressing obstructive symptoms, and subsequent improvement in quality of life.

A flexible digit with tactile feedback for invasive clinical applications.

This paper describes research on measurement of tactile sense using a flexible digit appropriate to endoscopy and minimal access surgery. It is envisaged that the sensing method will facilitate the navigation of flexible invasive devices, such as endoscopes, and also aid diagnosis using tactile perception as well as visual observation. The proposed master-slave digit system incorporates the application of the distributive sensing method applied to tactile sensing in order to discriminate different contact conditions of the flexible digit. The paper concentrates on the description of the application of this method and places this in the context of the user and the integrated system. The approach to sensing is able to discriminate the position, magnitude, distributed profile and width of the applied contacting load by using only four sensing points. Values to describe these parameters are evaluated to an accuracy greater than 93 per cent.

The acceptance of hearing aids for children with otitis media with effusion.

Conservative treatment for otitis media with effusion (OME) led us to consider the use of hearing aids as a way of managing the associated hearing loss. This study aimed to assess the compliance of patients and acceptance of hearing aids for the management of children with OME. Thirty-nine children who had been given binaural hearing aids to manage OME were assessed at routine follow-up after six months. A clinician who did not prescribe the aid administered a questionnaire to assess compliance, change in symptoms and acceptance of the aids. Thirty-eight parents thought the aids were easy to use and 25 (66 per cent) were completely satisfied with the management. Aided hearing improved by a mean of 17 dB (Range 10-30) over three frequencies, 0.5, 1.0, 2.0 Khz and all parents reported subjective hearing improvement in their children. The stigma of an aid was reported as minimal under the age of seven. Hearing aids provide a non-invasive way of managing the problems associated with OME which is acceptable to certain parents and children. Long-term effects of using aids need to be evaluated before they can be recommended.

Lignocaine with adrenaline: is it as effective as cocaine in rhinological practice?

This double-blind study compares the effectiveness of two local anaesthetics with vasoconstrictive activity (10% cocaine and 4% lignocaine with adrenaline 1:1000) used in the nose. Anterior rhinomanometry was used to assess changes in nasal mucosal blood volume from a reduction in congestion of the nasal mucosa with a resulting reduction in nasal resistance. Nasendoscopy was then performed and the degree of subjective discomfort evaluated. Twenty patients presenting with nasal obstruction but without evidence of structural disease and nine healthy volunteers were entered into the study. Each received 10% cocaine in one nostril, and 4% lignocaine with adrenaline (1:1000) in the other in a double-blind study. In all subjects, there was a significant reduction of nasal resistance after the administration of both drugs (P < 0.005). The anaesthetic effects of both agents were comparable with subjects reporting only a mild discomfort during nasendoscopy. We conclude from this study that 4% lignocaine with adrenaline (1:1000) solution is as effective as 10% cocaine.

Aspirating middle ear effusions when inserting ventilation tubes: does it influence post-operative otorrhoea, tube obstruction or the development of tympanosclerosis?

This prospective study examined the influence of aspirating middle ear effusions, immediately prior to ventilation tube insertion, upon the subsequent development of otorrhoea and tympanosclerosis. 50 children were studied and aspiration of effusions did not influence the incidence of purulent otorrhoea or ventilation tube obstruction within 1 month of surgery. The development of tympanosclerosis did not correlate with effusion aspiration, but in those ears which had an effusion aspirated there was a relation between operative bleeding and the development of tympanosclerosis.

Sublabial rhinotomy with septal transfixion as an approach to the nasal fossa, paranasal sinuses and nasopharynx.

A sublabial incision with septal transfixion and mid-face degloving is described as an approach to the nasal cavity, paranasal sinuses and nasopharynx. A brief history of the development of the technique is given. The results of nine cases are presented. These cases have had good tumour clearance, excellent cosmetic results and the minimum of complications. The sublabial approach is most useful in children and women, particularly those with intermediate grade tumours. The advantages of the approach compared to the lateral rhinotomy incision include: superior access to the floor of the nose, inferior turbinate and anterior nasal septum; access to both sides of the nasal septum and the absence of a facial scar. The limitations of the sublabial technique are the poor access to frontal sinus and the cribriform plate.

Digital and mirror assessment of the adenoids at operation.

The size of an adenoid is generally considered to be a significant factor in the causation of Eustachian tube dysfunction and glue ear in children. We studied 120 consecutive cases of children undergoing adenoidectomy. Our aim was to assess the accuracy of the digital and mirror examinations in identifying adenoid size. Two surgeons of 1 and 2 years' experience in the speciality were found to have a statistically significant correlation between mirror examination and the amount of adenoid removed at operation. One surgeon of 4 years' experience was found to have a higher degree of correlation for both mirror and digital examinations.

Cricothyroid muscle paralysis: its recognition and diagnosis.

Cricothyroid muscle paralysis is often missed as the symptoms are not dramatic and the laryngeal observations, on conventional indirect mirror examination, are inconclusive. The anatomy and physiology of the superior laryngeal nerve (SLN) and cricothyroid muscle are described. Three case reports are presented to illustrate our diagnostic techniques. Videofibrolaryngoscopy and electromyography are found to be invaluable tools for the diagnosis of this condition. The importance in diagnosing this entity is discussed.

Chronic aspiration and laryngeal competence.

Aspiration into the lower respiratory tract can be detrimental to life. Ten patients, suffering from neurological dysphagia with aspiration, were studied. Neurological disorders can cause inadequate glottic closure resulting in aspiration. It has not been well recognized however, that even patients who have full glottic closure are still capable of aspirating in the pre- and post-deglutition stages of swallowing. The combined techniques of videofibrolaryngoscopy and videofluoroscopy are found to be the best methods for demonstrating these abnormalities. Development of new techniques, in the prevention of aspiration, should also take into account silent, pre- and post-deglutitional aspiration.

Local versus general anaesthetic in the management of the fractured nose.

Displaced fractured noses are usually manipulated under general anesthetic. The appearances of fractured noses were assessed and the airways measured by rhinomanometry before and after nasal manipulation in 29 patients. Seventeen received a local anaesthetic (LA) and 12 a general anaesthetic (GA) for the manipulation. Patients were generally pleased with the outcome and there were no significant differences between results in the 2 groups. Bony manipulation did not affect the nasal airway. Local anaesthesia was acceptable to all but one patient. The benefits, including those of cost and safety, of local anaesthetic for manipulation of almost all fractured noses are discussed.

The safety and efficacy of intra-nasal ethmoidectomy.

Each of the three types of ethmoidectomy: intra-nasal, trans-antral and external, has its supporters and detractors who argue about the efficacy and safety of the procedures. One hundred and five ethmoidectomies for nasal polyps are reviewed retrospectively. Regardless of the approach used, approximately half of these had recurrence of polyps and some patients had several revision operations. There were six complications specific to the surgery. None was serious but most occurred with external ethmoidectomy. The limitations of ethmoidectomy for nasal polyps, the reasons for the good safety record and the best means of training juniors in the procedures are discussed.