Patent Application
20190070413
The present technology is directed toward vestibular prostheses and associated systems and methods.
Vestibular disorders can be disabling conditions which result in imbalance, disorientation, and oscillopsia. There are currently no effective clinical strategies for the restoration of vestibular function following the loss of hair cells in the vestibular labyrinth. One strategy for treating vestibular loss is to replace natural vestibular sensation with electrical stimulation of the afferent vestibular nerve fibers using an implanted stimulator. The electrical stimulus can restore the afferent signal carried by the vestibular nerve, producing a restoration of movement-elicited behavior. A partial loss of vestibular function can also be treated with this strategy if the prosthesis allows natural sensation of rotation by the remaining intact hair cells.
Such a treatment requires that electrical stimulation be combined with natural stimulation to produce a summed response. However, the current designs of vestibular prostheses have many limitations. Most devices are implanted in the ampullae of individual canals, which can potentially compromise natural vestibular sensitivity of the implanted ear. The devices are also constructed to be totally implantable, which poses challenges in terms of power consumption and reliability, and limits the upgradability of the device. Accordingly, there exists a need for improved treatments for vestibular disorders.
The present technology is directed to vestibular prostheses and associated systems and methods. In several embodiments, for example, a vestibular prosthesis includes an external rotational sensor configured to receive velocity and orientation information. The vestibular prosthesis further includes an external processor configured to convert the velocity and orientation information into an audio signal. The audio signal is provided to a cochlear prosthesis, which applies stimulation to a semicircular ear canal in response to receiving the audio signal. In some embodiments, the processor and cochlear prosthesis communicate in real time via an inductive link of the cochlear prosthesis.
Certain specific details are set forth in the following description and in
The vestibular prosthesis 100 further includes a processor 104 configured to transform the signal received by the sensor 102. In several embodiments, for example, the processor 104 converts the velocity signal from the sensor 102 into an audio signal. In some embodiments, the output of the processor 104 can be a combination of multiple carriers. For example, the output could comprise the output of a right anterior canal channel, right posterior canal channel, and right lateral canal channel, each of which can be amplitude modulated by head velocity. In some embodiments, one or more of these channels can be scaled, amplified, and/or filtered. As will be described in further detail below, the transformation and combination of these carriers can provide for tailored stimulation treatments. While
The vestibular prosthesis 100 further includes a cochlear implant 106 configured to receive the transformed signal and/or commands from the processor 104 and apply stimulation to the inner ear in response to receiving the transformed signal. The cochlear implant 106 can be any cochlear implant known in the art. In a particular embodiment, the signal receiver/stimulator is a Nucleus Freedom cochlear implant made by Cochlear Limited.
As will be discussed in further detail below with reference to
The stimulation parameters can be controlled by pre-set programming or can be modified by a user or practitioner. For example, the cochlear implant 106 can be programmed to produce patterned electrical stimuli that do not require a head-related input signal. In some embodiments, a graphical user interface can control parameters such as pulse width (phase) and amplitude. Active and return electrodes can be configured for a monopolar or bipolar modes of stimulation. By manipulating a duration parameter, a single pulse or train of pulses can be chosen. In addition, a pulse train can be sinusoidally amplitude-modulated or frequency-modulated based on specified modulation limits and oscillation rate. Combined electrical and rotational stimulation can result in a summation of responses, thereby providing improved vestibular function.
The rate of stimulation by the leads 100 can vary to achieve the desired vestibular response. In some embodiments, for example, it may be physiologically desirable to be able to decrease the firing rate of a spontaneously active population of neurons. High-rate stimulation can be used to induce a partial depolarization block so that the firing rate can be reduced below what it would be at if there was no electrical stimulation. This allows the vestibular prosthesis 100 to both increase and decrease the spontaneous firing rate of its target neurons.
The sensor 102, processor 104, and/or cochlear implant 106 can communicate by wired or wireless connections, or a combination thereof. In some embodiments, for example, the processor 104 and cochlear implant 106 can be connected by an inductive link 118 (e.g., a radiofrequency link). The inductive link 118 can include an inductive power transfer unit. The inductive link 118 can provide the cochlear implant 106 with the required power from a wireless power supply system (e.g., a power supply system powering to the processor 104) to enable long-term cochlear implant operation without a large internal power source. In further embodiments, the cochlear implant itself 106 contains the inductive link 118. For example, the external portion of the cochlear implant 106 can communicate with the internally-implanted portion via the inductive link 118.
In some embodiments, the sensor 102, processor 104, and/or cochlear implant 106 can communicate in real-time. One or both of the sensor 102 and processor 104 can be integrated with the cochlear implant 106 or can comprise a separate component. In several embodiments, for example, the sensor 102 and processor 104 can be externally positioned while at least a portion of the cochlear implant 106 is internally positioned. As will be discussed in further detail below with reference to
In the illustrated embodiment, the leads 210 have a thin (approximately 140 μm diameter) distal portion 226 that is about 2.5 mm in length, which is designed to be inserted in the perilymphatic space adjacent to the ampulla of each semicircular canal. The leads 210 can have other dimensions in other embodiments. In some embodiments, the stimulation leads 210 comprise an electrode array. Each lead 210 can contain multiple (e.g., three) independent stimulation sites 216 that are 200-250 μm in length. The inserted distal portions 226 are designed to not occlude the lumen of the membranous labyrinth, and they can be implanted without impinging on the crista ampularis, thereby preserving the rotational sensitivity of the implanted canal.
The sensor 302 and processor 304 can interface with a cochlear implant (e.g., the cochlear implant 206 described above with reference to
The bone anchor attachment 434 can provide permanent or releasable attachment between the casing 320 and the skull. For example, in some embodiments, the bone anchor attachment 434 can further comprise a release mechanism (e.g., a quick-release pin) to readily detach the casing 320 from the skull. By fixedly attaching the casing 320 to the skull, the bone anchor attachment 434 can provide reliable transmission of very small accelerations and displacements over a full range of frequencies to the external sensors as required for a successful vestibular prosthesis.
The present technology offers several advantages over fully implantable systems. First, by having an external sensor and processor, these components can be serviced, replaced, or upgraded without additional surgeries, extending the usable life of the implanted prosthesis by allowing the overall device to incorporate technological advances through replacement of the external components only. Further, the implantable portion of the device, the cochlear prosthesis, can use existing, highly reliable receiver-stimulator technology. Further, by using an external processor coupled to the cochlear implant by inductive link, power consumption demands can be reduced and the reliability of the design can be increased.
From the foregoing, it will be appreciated that specific embodiments of the technology have been described herein for purposes of illustration, but that various modifications may be made without deviating from the disclosure. Certain aspects of the new technology described in the context of particular embodiments may be combined or eliminated in other embodiments. Additionally, while advantages associated with certain embodiments of the new technology have been described in the context of those embodiments, other embodiments may also exhibit such advantages, and not all embodiments need necessarily exhibit such advantages to fall within the scope of the technology. Accordingly, the disclosure and associated technology can encompass other embodiments not expressly shown or described herein. Thus, the disclosure is not limited except as by the appended claims.
This application claims the benefit of U.S. Provisional Patent Application No. 61/498,117, filed Jun. 17, 2011, which is incorporated herein by reference in its entirety.
This invention was made with government support under HHS-N-260-2006-00005-C awarded by National Institutes of Health (NIH). The government has certain rights in the invention.
| Number | Date | Country | |
|---|---|---|---|
| 61498117 | Jun 2011 | US |
