Group 6 :Choclear Implant Amir Mustakim Ab Rashid Nurdania Abd Rahman Nur Nadhirah Abdul Hamid Keerthana a/p Rangasamy

Presentation Outline 1. System Description 2. Input / Output 3. System Process 4. Performance Testing

System Description Current cochlear implants use a processor that is worn behind the ear Sound is sensed by the microphone of the processor and is processd using CIS or another processing strategy Encoded data parameters are transmitted through the skin from the transmitter to receiver over radio frequency. Magnets hold the processor on the head so that it can communicate with the implant The received data are decoded into stimulation inputs for 8 or more channels, which are sent to the electrode array

Continue… The electrode array resides in the cochlea, where it stimulates remaining spiral ganglia and auditory nerve

INPUT AND OUTPUT & SYSTEM PROCESS

Speech Input Processing Electrical Pulse

Inside the external unit

SYSTEM PROCESS continue...

Basic operation of cochlear implant The sound processor captures and digitises sound The antenna will transmit the digitised sound to the implan receiver The implant receiver transforms the digital information into an electronic signal sent to the cochlea Each electrode on the array corresponds to a signal frequency The auditory nerve is stimulated once encoded signal is transmitted to the corresponding electrode The brain receives the sound transmitted via the auditory nerve 1 2 3 4 5 6 https://youtu.be/-vZXgApsPCQ

Cochlear implantation process (general process) 1. APPOINTMENT AT COCHLEAR IMPLANTATION CENTER The cochlear implantation centre team consisting of: • A surgeon experienced in otologic surgery • An ENT doctor • An audiologist or technical audiologist, responsible for the audiometric evaluations and sound processor fitting • A speech therapist, responsible for language evaluation, followup and rehabilitation • A psychologist, responsible for evaluating the patient’s psychological suitability for cochlear implantation

2. Evaluations A series of tests and assessments are carried out team to evaluate whether a cochlear implant system is indicated for the patient. These include: • Detailed audiology assessment of the auditory capacities and auditory nerve function • Various medical examinations • CT scan and/or an MRI of the inner ear • Psychological assessment of the patient’s and/or family’s motivation for implantation and expectations • Speech and language assessment

3. Surgical intervention Surgery is required to insert the internal part of the implant system. cochlear implantation need an anaesthetic and lasting around 2 hours. After general or local anaesthetic, the surgeon makes an incision behind the ear and inserts the cochlear implant under the skin. An opening is made in the cochlea to carefully insert the electrode array. The surgeon checks the proper functioning of the implant before closing the incision and completing the operation.

4. Recovery The healing period lasts around 3 to 5 weeks During this time, most patients can generally resume normal activities. However, they still will be unable to hear

5. Activation and the first sounds After the recovery period, the patient receives the sound processor. To be able to hear the first sounds, the fitting audiologist must adapt the sound processor to the physiology of the user. Using dedicated fitting software, the audiologist creates a “sound map”. This determines the individual limits for each electrode to make hearing as clear and comfortable as possible. Each experience of activation is unique but it generally takes some time for the brain to adapt to this new type of stimulation.

6. Fittings and rehabilitation Speech therapy and rehabilitation programs and attending all sound processor fitting sessions are highly recommended. Fitting sessions are scheduled frequently, but they become less frequent once settings are optimised. An annual visit is required to monitor progress and continue fine tuning.

Risk of surgery Meningitis Facial nerve Infection Device failure

Performance testing

Biocompatibility Test  property of a material being biologically compatible by not producing a toxic, injurious, or immunological response in living tissue. The materials used to fabricate implantable system components need to be compatible with the tissue and structures in the vicinity of the device and need to be appropriately selected for their specific use.

Electrode array and lead testing Purpose Criteria Physical dimensions and performance characteristic To verify the physical dimensions and electrical properties The length of the array must be verified as part of the electrode assembly verification; Tensile Test To demonstrate that the electrode withstands tensile forces that might occur during or after implantation, without fracture of any conductor or deterioration to any functional electrical insulation Two test: Sustained tensile force of min 1.05N for at least one min All insulation impedance > 100KΩ direct current resistance for each active electrode wire ≤ 100Ω

Test Pupose Criteria Multiple Insertion test To demonstrate sufficient robustness of the electrode to withstand the forces exerted during implantation The array is to withstand 4 times partial insertions into an obstructed scala tympani model and 2 times full insertions into an open scala tympani model without any open and/or short circuit Flex Test (Drop Test) To demonstrate that the electrode withstands the flexural stresses that might occur during implantation as required No open or short circuit after five times of stimulator drop must be shown, while the lead is clamped close to the most proximal electrode contact Sterilization Evaluation To perform the sterilization validation via product adoption Temporal Bone To asses the insertion trauma caused by the electrode Electrodes were inserted into scala tympani with the same procedures via the round window(RW). Various evaluations were performed to verify that the insertion properties of the electrode are acceptable for human implantation.

Test Purpose Criteria Verification of front-end hearing aid firmware To verify the front-end hearing aid firmware meets its requirement Function of the firmware perform as intended, and operate within prescribed values. Environmental requirements To verify the mechanical and electric performance under the environment stress during daily use temperature range for operation: 0⁰C to 50⁰C temperature range for storage : -20⁰C to 60⁰C Relative humidity range : 10% to 93%