New micromanipulator for precise operations involving cochlear and middle ear implants

Mar 12 2010

A team of engineers from the CEIT-IK4 technological centre and doctors from the University Hospital of Navarra have designed a new tool for operating on the inner ear with maximum precision, reducing the possibility of damage to the auditory function during the surgery. This is the first micromanipulator specifically for operations involving cochlear and middle ear implants, of which about a hundred are carried out in this hospital annually. Taking part in developing the new tool were four engineers from CEIT and five ear, nose and throat specialists from the University Hospital of Navarra.

The new technique was presented at the XI International Symposium on Cochlear Implants, organised by the Department of otorhinolaryngology (ENT) at the University Hospital of Navarra, attended by 200 specialists from all over the world.

The micromanipulator, patented by the University of Navarra, is a surgical working tool the aim of which is to aid the surgeon in those situations involving very small dimensions and which are highly sensitive - such as the inner ear, the size of which is less than the nail of a forefinger. Working with precision in such a small space and with such a delicate structure is highly complicated. The micromanipulator enables operating with precision in spaces of these small dimensions, working in tandem with auditory surgical microinstruments. In short, the micromanipulator is a tool for working with the inner ear in a precision manner, without affecting its function.

This micromanipulator has two parts. One of these is anchored to the temporal bone of the patient, its function being to act as support for a series of elements which go together with the milling tool. The surgeon makes a hole in the temporal bone with this tool, in order to gain access to the inner ear. In the centre of this second series of elements is a small metallic part the behaviour of which is flexible and this device provides the surgeon with greater control and precision on milling, making up for the vibrations of the hand itself.

New phase in inner ear surgery

The design of the micromanipulator is the beginning of a new era in inner ear surgery and a new line of research. To date, the inner ear has meant a barrier for the surgeon, as has happened in other stages of medical history - when, for example, the heart was considered an untouchable organ as it was thought that death would ensue. The same occurred with the inner ear - it could not be accesses because it was thought that its functioning would be damaged. In recent years, however, especially with cochlear implants, they have learnt how to gain access to the inner ear without these operations necessarily causing damage.

Amongst the main advantages of the micromanipulator is its enhanced precision in working, as it enables operating on the inner ear in a more exact manner, opening up a series of possibilities depending on techniques already developed for the treatment of illnesses that can affect this zone of the auditory system.

This is why the applications of the micromanipulator are currently focused on cochlear implants and auditory implants of the middle ear. But, in the future, the technique could be used for introducing stem cells in order to regenerate the inner ear and secrete certain pharmaceutical drugs that provide the possibility of curing diseases that may arise in the zone.

Joint working between University Hospital of Navarra and CEIT

The development of the micromanipulator is the first joint venture between ear, nose and throat specialists at the University Hospital and researchers at CEIT, the first in a series with which they wish to continue. The medics set out their requirements and the engineers then seek and devise solutions and tools that enable the former to resolve their problems. For the engineers the start of this venture was curious because they had to learn the anatomy and physiology of the ear in order to know the terrain in which they were moving so as to develop these instruments.

As regards extending the use of this surgical tool to other medical centres, the specialists confirmed that it is currently being validated at other European hospitals.