Chris Coulson

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.

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.

The effect of operating time on surgeons' muscular fatigue.

INTRODUCTION A study was completed to determine if operating has an effect on a surgeons muscular fatigue. SUBJECTS AND METHODS Six head and neck surgery consultants, two ENT registrars, 20 normal controls from two tertiary referral centres in the West Midlands participated in the study. Electromyography (EMG) measurements were taken throughout a day of operating and fatigue indices were compared to controls performing desk work. RESULTS The percentage changes in mean frequency of muscular contractions were examined; there was no significant difference in fatigue levels between consultants and registrars. Operating led to an increase in fatigue in all subjects, compared to no increase in controls performing desk work. It was also found that the brachioradialis muscle is used more than the mid-deltoid muscle and, hence, fatigues at a faster rate. CONCLUSIONS Surgeons should be aware that their muscular fatigue levels will increase as an operation progresses; therefore, if possible, more complex parts of the operation should be performed as early as possible, or, in the case of a very long operation, a change in surgeon may be necessary.

Tympanoplasty for Chronic Tympanic Membrane Perforation in Children: Systematic Review and Meta-analysis

Objective To study the effectiveness of Type 1 tympanoplasty for chronic tympanic membrane perforations in the pediatric age group and to investigate factors influencing its success. Data Sources Searches were conducted of the MEDLINE database and the Cochrane Database of Systematic Reviews using terms focused around tympanoplasty and children. Searches were performed on June 23, 2014 and limited to English language entries since January 1, 1997. Study Selection Studies reporting tympanoplasty closure rates in children 18 years and younger, with a minimum follow-up of 6 months, were included. Studies focusing on more advanced forms of tympanoplasty and revision surgery were excluded. Data Extraction Five hundred sixty-four articles were screened identifying 2,609 cases from 45 eligible studies. Data were collected by consensus of the first two authors with the third author arbitrating disparities of opinion. Success was taken as the closure rate at 12 months where possible. Data Synthesis Forest plots with Mantel-Haenszel analyses were used to compare closure rates with respect to perforation size, adenoidectomy, status of contralateral ear, Eustachian tube function, active infection, and graft position. Linear regression and Fisher’s exact were used to analyze closure rate with respect to age. Conclusion The mean weighted closure rate for pediatric tympanoplasty was 83.4%. Subgroup analysis found age not to be a significant factor affecting the closure rate. Tympanoplasties performed on larger perforations or in children with abnormal contralateral ear findings were more likely to fail. Surgery may be best delayed until contralateral otitis media with effusion has settled.

The effect of operating time on surgeon’s hand tremor

The objective of this prospective study, performed at two tertiary referral centers in the West Midlands, was to determine if operating has an effect on a surgeon’s baseline tremor. A total of 10 head and neck surgery consultants, 2 ENT registrars and 19 normal controls participated in the study. The interventions were preoperative and postoperative tremor measurements for surgeons and pre and post-days’ desk work for controls, with the main outcomes measure being the percentage change in tremor. No difference in baseline tremor was determined between consultants and registrars. Operating led to an increase in hand tremor in all subjects. Tremor increases in all subjects were directly proportional to the length of the time spent in operating. Operating compared to a normal day’s desk work increased tremor by a factor of 8.4. In conclusion, surgeons should be aware that their tremor will increase as an operation progresses. More complex parts should be performed as early in the day as possible, or, in the case of a very long operation, a change of surgeons may occasionally be necessary.

The effect of supporting a surgeon's wrist on their hand tremor

Background. Operative tremor can greatly influence the outcome of certain, precise, microsurgical operations. Reducing a surgeons tremor may not only improve the operative results but decrease the operative time. Previous studies have only measured uni or bi directional tremor and therefore have been unable to calculate both the overall tremor amplitude and the tremor reduction by resting the wrists. Materials and methods. We measured the tremor of 21 neurologically normal volunteers while performing a micromanipulation task, with and without wrist support. Measurements were acquired in three dimensions using three accelerometers attached to the hand, allowing an overall tremor amplitude to be calculated. Results. Resting the wrist on a gelled surface decreases an individuals tremor by a factor of 2.67 (P = 0). Conclusions. Supporting the wrists significantly decreases the amplitude of the tremor. Surgeons should consider using wrist supports when performing parts of operations which necessitate a high degree of accuracy.

Robustness analysis of a smart surgical drill for cochleostomy

There is a need for sensor‐guided robotic devices that discriminate working conditions and media, and control interaction of tool‐points with respect to tissues. At the micro‐surgical scale the need is to control exact penetration through flexible tissues and to control relative motion with respect to moving or deforming tissue targets and interfaces.

A cochlear implantation robot in surgical practice

Cochlear implantation has become the standard treatment for severe to profoundly deaf patients over the last 20 years and is likely to increase as instrumentation systems improve such that patients with less deficiency can benefit and if the procedure can lead to accurate and a more efficient process of implantation. The critical step in the operation appears to be creating the cochleostomy, through which the implant electrode can be passed. A cochleostomy is created by drilling away the bony outer cochlea wall and, ideally, leaving the underlying endosteal membrane intact. The membrane is opened with a knife and implant is inserted. Inadvertent protrusion of the drill through the endosteal membrane may damage the scala tympani or osseous spiral lamina, and will contaminate the endolymph and perilymph with bone dust which, combined with the pressure surge experienced, may lead to a reduction in residual hearing. If the endosteal membrane is not perforated during the drilling process, and is opened by a knife, the damage to the cochlea will be minimised and residual hearing will be preserved. It has been shown that robotics can be applied in microsurgical tasks as a tool by automatically controlling the interaction between tissue and the tool point. The research reported here has led to clinical trials of an autonomous surgical robot system able to carry out the critical process of penetrating the bone tissue of the wall of the cochlea without penetration of the endosteal membrane located immediately inside the cochlea. Use of the robotic micro-drill in theatre represents the first application of an autonomous surgical robotic device and has shown that this is the ideal way to prepare a cochleostomy. The consistent results and the smooth form of the cochleostomy will enable more consistent insertion of implant electrodes and the likelihood of consistent results in terms of electrode performance. The means to avoid penetration of the endosteal membrane is expected to lead to a reduced complication rate.

Pseudotumour of the temporal bone: a usual cause of otorrhoea and facial palsy

An inflammatory pseudotumour of the temporal bone is a rare, idiopathic, fibro-inflammatory lesion which mimics malignancy. Although such a lesion is known to occur elsewhere in the body such as the liver, abdominal viscera, pelvis, thorax and the upper respiratory tract, the involvement of the temporal bone is extremely unusual. We present such a case in a 60-year-old man, which provided a great diagnostic challenge. We review the key radiological and histological results that confirmed the diagnosis and demonstrated for the first time that oral steroids alone may completely resolve the condition.

A smart micro-drill for cochleostomy formation: a comparison of cochlear disturbances with manual drilling and a human trial

Abstract Background Cochleostomy formation is a key stage of the cochlear implantation procedure. Minimizing the trauma sustained by the cochlea during this step is thought to be a critical feature in hearing preservation cochlear implantation. The aim of this paper is firstly, to assess the cochlea disturbances during manual and robotic cochleostomy formation. Secondly, to determine whether the use of a smart micro-drill is feasible during human cochlear implantation. Materials and methods The disturbances within the cochlea during cochleostomy formation were analysed in a porcine specimen by creating a third window cochleostomy, preserving the underlying endosteal membrane, on the anterior aspect of the basal turn of the cochlea. A laser vibrometer was aimed at this third window, to assess its movement while a traditional cochleostomy was performed. Six cochleostomies were performed in total, three manually and three with a smart micro-drill. The mean and peak membrane movement was calculated for both manual and smart micro-drill arms, to represent the disturbances sustained within cochlea during cochleostomy formation. The smart micro-drill was further used to perform live human robotic cochleostomies on three adult patients who met the National Institute of Health and Clinical Excellence criteria for undergoing cochlear implantation. Results In the porcine trial, the smart micro-drill preserved the endosteal membrane in all three cases. The velocity of movement of the endosteal membrane during manual cochleostomy is approximately 20 times higher on average and 100 times greater in peak velocity, than for robotic cochleostomy. The robot was safely utilized in theatre in all three cases and successfully created a bony cochleostomy while preserving the underlying endosteal membrane. Conclusions Our experiments have revealed that controlling the force of drilling during cochleostomy formation and opening the endosteal membrane with a pick will minimize the trauma sustained by the cochlea by a factor of 20. Additionally, the smart micro-drill can safely perform a bony cochleostomy in humans under operative conditions and preserve the integrity of the underlying endosteal membrane.