Technical Field

The present invention relates to a data transfer system which realizes data transfer by performing radiation at visible and/or infrared wavelengths passing through the eardrum between the internal ear and the external ear (transtympanic) in cochlear implant devices.

Background of the Invention

Although there may be a number of software and hardware differences among cochlear implant (CI) systems being currently used (conventional), their forms of operation and overall designs are quite alike. Two basic subunits serve in the operating system of a CI system. These subunits are divided into two units, namely external and internal unit. The external unit essentially consists of microphone, battery, processor, transmitting antenna and magnet. Whereas the internal unit contains receiving antenna, magnet, receiving/stimulating electronic module, grounding electrode and electrode array.

An internal unit is the piece which is inserted by CI surgery. This internal unit generally consists of electronic components included in a hermetic box; receiving antenna, magnet outside the box; and electrode array entering the cochlea by exiting the box. The piece consisting of the receiving antenna, the magnet and the hermetic box are inserted onto the outer surface (implant bed) of the temporal bone squamous part, under skin and soft tissues by surgery. Upon exiting the implant bed, the electrode array enters from the mastoidectomy cavity after proceeding on the temporal bone squamous part. It reaches the middle ear by means of the facial recess after passing through the mastoid cavity, and enters the cochlea through the round window. Each conductor in the electrode array terminates with an electrode surface. Except the electrode surface, all parts of the internal unit are covered with a biocompatible and insulating material.

In conventional CI systems, data transfer to an implanted part is only possible by induction from mutual transmitting/receiving antennas. Audio signals are carried by being modulated to high frequencies. Coils in internal and external parts (modules) are in interaction for both power and data transfer. Data transfer by induction technique shortens the operating time of the external module and affects the user experience negatively by causing high energy consumption.

In conventional CI systems, presence of magnet leads to distortion of image quality in magnetic resonance imaging (MRI) and causes the device to be subjected to significant torque and force. Conventional cochlear implants have MRI compatibilities of different degrees. In some of these, surgical procedures such as removing the magnet prior to the procedure so as to have MRI and placing it again following the MRI are required. And some may have low-power MRI’ s by applying pressure on the device prior to the procedure by means of some splints and restricting the head position. Even in conventional Cl’s, that can have MRI, a magnet removal procedure is necessary in order to acquire a clear image from the head region. This procedure subjects the user to additional surgical interventions before and after MRI and it may cause the user to suffer by leading to device breakdown, transmission of infection, inability to have MRI in case of emergency as well.

In conventional Cl’s, a strong magnet is used in an implanted part in order to have an uninterrupted data and energy transfer and to keep the transmitting antenna in the external module in the right position. However, due to the fact that an uninterrupted induction connection will not be needed in a CI assembly including a battery or a similar integrated energy system in its internal part and having a transtympamc data transfer system, it is not necessary to use a magnet. Thereby, MRI compatibility and quality of an acquired image enhance a lot. Because no uninterrupted energy transfer is required and the energy transfer is not as sensitive as data transfer to the location of receiving/transmitting antennas, the charging process -that will qualify for being carried out intermittently- can be carried out by means of a cap to hold the transmitting antenna in the correct position.

When the internal part of the device breaks down in conventional Cl’s, it is necessary to replace the whole internal part by a CI surgery again. In this case, a more difficult and stressful surgery awaits the surgeon because of the changes caused by the first surgery. This is because it is seen that the previous electrode beam usually leads to fibrosis response within the scale tympani by triggering reaction of foreign substance and a much narrower gap remains. And this removalinsertion procedure becomes more difficult and risky in patients with internal ear abnormalities that are seen in one-fifth of infant CI candidates. Occurrence of cerebrospinal fluid leakage that may cause risk of meningitis during removal of the old electrode beam, the facts that the new electrode beam inserted progresses to points such as internal acoustic meatus where it should not enter, and the new localization of the electrode beam stimulates the cranial nerves other than the auditory nerves are some of undesirable conditions that may be experienced. Being aware of the disappointment that a possible failure will cause during insertion of the electrode beam into the cochlea also increase this problem.

In the event that a breakdown occurs in the internal part in conventional Cl’s, it is not possible to leave the electrode beam in the patient as implanted and to replace other parts of the device. No detachable connector assembly is available to make this possible. Importance of a connector assembly increases in a design that will comprise an integrated energy system, wireless connection assembly, active electronic components, etc. particularly beyond conventional CI systems due to the fact that the will be a lot more components which may break down, lose their characteristic in time or technology of which may outdate. Data transmission at high frequencies is provided at certain bandwidths by means of coils in the internal and external units. Measures should be taken in communication systems based on radio frequency because of the decrease in signal amplitude obtained in the receiver between electromagnetic interference and coils. Coil-based data transmission may not be provided with high efficiency. The efficiency of power and data transmission decreases significantly when the bandwidth wherein the coils operate efficiently is exceeded. The receiving and transmitting coils lead to size constraints in conventional Cl’s.

Due to these reasons, there is need for a CI which contains an energy source in its internal part; does not need a receiving and transmitting antenna or coil for data transfer; is non-magnetic; has a connector system that will enable to replace the unit in the implant bearing by leaving the electrode beam in the patient in case of a breakdown; has a data transfer system that enables to transmit audio data by means of light waves without needing a specific bandwidth at high resolution, by being compressed or coded between the external ear and the internal ear; and has a low visibility externally.

The United States patent document no. US6390971, an application in the state of the art, discloses a hearing aid for performing encrypted data transfer. The hearing aid is inserted within the middle ear of a hearing-impaired person and enables to transmit sound waves that will pass through the eardrum, via infrared or ultrasonic signals in an encrypted way by means of the receiver/transmitter it has.

Summary of the Invention

An objective of the present invention is to realize a data transfer system which realizes data transfer by performing radiation at visible and/or infrared wavelengths passing through the eardrum between the internal ear and the external ear in cochlear implant devices. Another objective of the present invention is to realize a data transfer system which enables to send the audio data transmitted from eardrum by means of sound waves by using CI devices upon being compressed, coded and synchronized.

A further objective of the present invention is to realize a configuration of data transmitting CI external module which is located inside the external auditory canal for CI devices that are integrated energy source in its internal part, and has a low visibility externally.

A yet further objective of the present invention is to realize a CI configuration which does not contain magnet in its internal part.

Detailed Description of the Invention

“A Data Transfer System Used in Cochlear Implant Devices” realized to fulfil the objectives of the present invention is shown in the figure attached, in which:

Figure l is a schematic view of the inventive data transfer system.

The components illustrated in the figure are individually numbered, where the numbers refer to the following:

1. System

2. External module

2.1. External receiver/transmitter

3. Internal module

3.1. Internal receiver/transmitter

K: Eardrum The system (1) which has an energy source in its internal part; realizes data transfer by performing radiation at visible and/or infrared wavelengths passing through the eardrum (K) between the internal ear and the external ear in CI devices with enhanced compatibility for magnetic resonance imaging (MRI) devices comprises:

- at least one external module (2) which is placed in such a way as to be close to the eardrum (K) in the external auditory meatus and comprises at least one external receiver/transmitter (2.1); and

- at least one internal module (3) which is placed in such a way as to be close to the eardrum (K) in the internal ear and comprises at least one internal receiver/transmitter (3.1) enabling to perform sound transmission upon being compressed, coded and synchronized by use of sound waves with the external receiver/transmitter (2.1).

The external module (2) included in the inventive data transfer system (1) comprises at least one microphone, control buttons, an energy source such as battery, sound processor, integrated circuits inside the external auditory meatus such that they are directed outside the ear; and an optoelectronic external receiver/transmitter (2.1) on its side facing the eardrum (K). The external receiver/transmitter (2.1) enables to receive audio signals coming from the outside to the ear, to denoise the audio signal and to amplify it before being sent to the internal receiver/transmitter (3.1) by proceeding to the internal ear side of the eardrum (K). In a preferred embodiment of the invention, the external receiver/transmitter (2.1) comprises a light transmitter that is LED or GaAlAs IR Led, and a receiver that is a photodetector. The external receiver/transmitter (2.1) can be hidden by being inserted into the external auditory meatus contrary to applications that are inserted outside the ear and lead to the fact that it is easily noticed from the outside that a hearing device is being used. There is not any physical connection between the external module (2) and the internal module (3). Due to the fact that the external module (2) has no physical connection with the internal module (3), it is not necessary anymore to be removed out of the ear in the internal module (3) for the part replacement in case of experiencing any problem and the operator’s work -who will perform the operation- can be simplified. The external receiver/transmitter (2.1) is located on both sides of the internal receiver/transmitter (3.1) and the eardrum (K), and provides the data transfer between these by means of visible or infrared (IR) light. A line of sight is located on the eardrum (K) between the external receiver/transmitter (2.1) and the internal receiver/transmitter (3.1), and the light waves proceed on this line. Transmission of the audio data performed by means of light waves between the external receiver/transmitter (2.1) and the internal receiver/transmitter (3.1) is realized by using signal modulation techniques. A direct data transfer can be performed from the external receiver/transmitter (2.1) to the internal receiver/transmitter (3.1) by switching on-off (on-off switching) the LED lights owned. Besides, intensity of the light between the external receiver/transmitter (2.1) and the internal receiver/transmitter (3.1) can be changed in order to increase the data transmission rate; i.e. light signals can be transmitted at four different levels in such a way as to be off, intensity of 1/3, intensity of 2/3 and full intensity; thus the data transmission rate can be doubled. The data transmission performed in this way is called as amplitude shift keying (ASK) or pulse amplitude modulation (PAM). To generalize, the data transmission rate can be increased for log2(M) times at the same signalling period by M level (M-ASK or M-PAM) and (0, 1/(M-1), 2/(M-l), full intensity). A current source circuit (current generator) is present in order to use the LED luminance at a desired value. The external receiver/transmitter (2.1) enables to decrease the amount of data to be transferred by compressing the raw audio signals to be transmitted to the internal receiver/transmitter (3.1), and to perform transfer by reducing the energy required for transmission. The external receiver/transmitter (2.1) ensures that audio signals, that will be transmitted to the internal receiver/transmitter (3.1), are transmitted such that their synchronization errors are reduced and communication quality is enhanced by increasing the communication bandwidth. The external receiver/transmitter (2.1) utilizes channel coding techniques in order to provide data reliability for the audio signals to be transmitted to the internal receiver/transmitter (3.1), and thus enables to transfer data with a higher accuracy and lower error. In addition, the external receiver/transmitter (2.1) utilizes channelling signal processing techniques enabling the speech signal to be transmitted upon being divided into frequency channels in order to protect the audio signals, that will be transmitted to the internal receiver/transmitter (3.1), against decrease of quality during transmission.

The internal module (3) included in the inventive data transfer system (1) comprises at least one energy source such as battery, and an optoelectronic internal receiver/transmitter (3.1) being integrated to the electrode beam -which is inserted into the cochlea- part that will correspond to the middle ear or extending to the middle ear in the form of a separate extension. In a preferred embodiment of the invention, the internal module (3) comprises a connector system that will enable to replace the components in the implant bearing by leaving the components in the middle ear and the internal ear on-site. The internal receiver/transmitter (3.1) enables to receive the audio data -that is sent from the external receiver/transmitter (2.1) by use of sound waves- after it passes through the eardrum (K) and to interpret the said data upon being brought to necessary levels by processing. In a preferred embodiment of the invention, the internal receiver/transmitter (3.1) comprises a light transmitter that is LED or GaAlAs IR Led, and a receiver that is a photodetector.

With the inventive data transfer system (1), audio data is transferred directly or in a coded way by means of radiation that is used in a CI assembly which is inserted into the body surgically for enabling patients with severe or complete sensorineural hearing loss to perceive sounds and which stimulates the cochlea electrically according to the sound information received from the outer environment, and that is performed at visible and/or infrared wavelengths passing through the ear drum between the internal ear and the external ear (transtympanic) bi-directionally. Due to the fact that audio data is transferred by means of light waves, the modules inserted into the internal ear and the external ear do not have a physical connection with each other and no intervention is required for the module (3) in the internal ear when it is needed to replace the module (2) in the external ear. And this simplifies the operator’s work and also poses less risk for the patient. Besides, the audio data -which is transmitted upon passing though the eardrum- is compressed, coded by means of the energy source comprised by the external module (2) and the internal module (3) and data transfer can be possible by lower energy without having loss in sound quality by performing synchronization. Because the external module (2) inserted into the external auditory meatus is not located outside the ear, it is not easily noticed that the person has impaired hearing and it is more long-lasting due to the fact that it will be less likely to be subjected to impact as well. In addition, because the data transfer system (1) does not contain a magnet in its internal part, it is not necessary to remove the cochlear implant when the patient enters magnetic resonance imaging (MRI) devices and the compatibility with MRI devices is enhanced.

Within these basic concepts; it is possible to develop various embodiments of the inventive data transfer system (1); the invention cannot be limited to examples disclosed herein and it is essentially according to claims.