Cochlear implant drug delivery device

Abstract

Devices for the delivery of a bioactive substance to a cochlea and methods of delivery thereof. The devices include means to allow the release of the bioactive substance within a cochlea.

Description

FIELD OF THE INVENTION[0001]The present invention relates to an implantable device and, in particular, to an implantable device for use in delivering pharmaceuticals to a cochlea following implantation of an electrode assembly.BACKGROUND OF THE INVENTION[0002]Hearing loss, which may be due to many different causes, is generally of two types, conductive and sensorineural. Of these types, conductive hearing loss occurs where the normal mechanical pathways for sound to reach the hair cells in the cochlea are impeded, for example, by damage to the ossicles. Conductive hearing loss may often be helped by use of conventional hearing aid systems, which amplify sound so that acoustic information does reach the cochlea and the hair cells.[0003]In many people who are profoundly deaf, however, the reason for deafness is sensorineural hearing loss. This type of hearing loss is due to the absence of, or destruction of, the hair cells in the cochlea which transduce acoustic signals into nerve imp...

AI Technical Summary

Benefits of technology

[0047]In yet another embodiment, at least some of the pores in one, some or each of the porous portions can have relatively smooth internal walls. In another embodiment, at least some of the pores in one, some or each of the porous portions can have rippled internal walls. The ripples can have a suitably small dimension to preferably at least substantially prevent wetting of the cavities thereby minimising friction between the bioactive substance and the walls.

[0049]In a further embodiment, at least some of the pores of the porous portion can be preferably adapted to be at least substantially closed when the elongate member is at least substantially straight thereby preventing migration of any bioactive substance held within said at least some pores from these pores. On adopting a curved configuration, said at least some pores can be adapted to at least partially open allowing migration of the bioactive substance therefrom.

[0094]In a preferred embodiment, the lead can be provided with a stop means that prevents the body of the substance delivery means from being moved relatively past the stop means and onto the elongate member. In another embodiment, the stop means can comprise a stop member that, once engaged with the body, prevents subsequent slidable movement of the collar relative to the lead in either direction.

[0107]The membrane can act as a valve means that allows fluid to exit the chamber but prevents, or at least substantially prevents, fluid flow from external the chamber back into the chamber within the body.

[0118]It is also envisaged that substances that assist in reducing the resting potential of the surrounding neurons can also be delivered by the present invention. It should be appreciated that during neural stimulation the neurons propagate an action potential through the response of transmembrane ion channels to local electrical fields. By delivering a substance that elicits a change in the transmembrane potential, the resting neural membrane potential can be moved towards the activation potential resulting in a lowering of the energy required to be delivered to activate the neuron. This also has the potential to reduce the power required by the stimulation device as well as increase the specificity of the electrical stimulation and restore the stochastic response of the neurons.

Problems solved by technology

Of these types, conductive hearing loss occurs where the normal mechanical pathways for sound to reach the hair cells in the cochlea are impeded, for example, by damage to the ossicles.

In many people who are profoundly deaf, however, the reason for deafness is sensorineural hearing loss.

These people are thus unable to derive suitable benefit from conventional hearing aid systems, because there is damage to or absence of the mechanism for nerve impulses to be generated from sound in the normal manner.

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