Complete System

Brain Interchange System

Principle of Function

As an investigational device, the fully implantable system is designed for both recording and stimulating on 32 channels.
It is intended for long-term measurement of neuronal activity and electrical stimulation of neuronal tissue in the brain.


CorTec Brain Interchange receives electric signals from the connected electrodes and amplifies, digitizes and transmits them to a computing unit via the External Unit.
The System is able to produce electrical impulses using parameters provided by the Application Software on a computer and can transmit them to electrodes of the Multi-Part Implant.


The Application Software on the computer manages the telemetry (programming of indication related parameters, accessing the system information, and data transmission) and analyses the data.
It creates the commands for the implanted electronics to generate stimulation patterns.


< Demonstration Video of Brain Interchange Technology

Complete System, Brain Interchange ONE, Brain Interchange System

Brain Interchange Platform Technology

The unique Brain Interchange Technology can be designed to fit your specific needs.

The requirements of a specific complete system can vary depending on the applications approach. We can customize Brain Interchange so that each component of the system meets your specific needs. At the end stands your own system with unique features which fit exactly to your application.

Brain Interchange ONE

Brain Interchange One is the first version of the CorTec Brain Interchange Technology which we are currently validating for the use in clinical trials.
In the following you can get more detailed information about the specific product features and design options of this first version.


Device Description

The implantable technology platform features full wireless functionality for chronic open- and closed-loop interaction with the nervous system. It consists of 3 components:

Multi-Part Implant


The Multi-Part Implant comprises Implanted Internal Electronics Unit and 1 or 2 ECoG electrodes plus one optional ground (GND) electrode contact.

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Similar to CorTec’s FDA cleared °AirRay Cortical Electrode all electrodes based on the °AirRay electrode technology are capable of recording and stimulating brain activity. Produced in a proprietary laser manufacturing process, °AirRay electrodes are very soft, thin and flexible. They adapt well to the brain‘s curvature.


According to your requirements, customized electrodes can be tailored to fit the needs of your specific system design.


In addition to the use of CorTec electrodes, the system can also be equipped with DBS electrodes. A validation of the interconnection of the Brain Interchange implant to a connection cable for market approved DBS electrodes can be executed upon request.

Implanted Internal Electronics Unit

The Implanted Internal Electronics Unit consists of a hermetically sealed ceramic encapsulation, electronics and firmware. It is powered wirelessly and communicates via a radio-frequency link.


The Implanted Internal Electronics Unit with hermetic package, inductive power receiving coil, and electrode interconnection area is placed underneath the scalp, partly embedded in the skull. The electrodes implanted on the surface of the brain are in direct contact with the central nervous system. When used as intended, the Internal Electronis Unit will be permanently implanted approximately 4 cm above the tragus of the mastoid cavity.


For long-term stability, the implant electronics are protected against body fluids by a hermetic encapsulation. Device safety is monitored by multiple sensors inside the hermetic package.


°AirRay electrodes are made from silicone and platinum-iridium (90:10). Other contact materials or coatings can be provided upon request. For some designs the use of a hybrid silicone-Parylene C substrate is the recommended solution.


The ground electrode consists of a ring made from platinum-iridium (90:10) located at the end of a medical-grade silicone tube. It is connected to the Implanted Internal Electronics Unit.


The Implanted Internal Electronics Unit is casted in medical-grade silicon rubber. It contains a hermetic ceramic encapsulation to protect the electronic circuits.


The °AirRay ECoG electrodes are made from platinum-iridium (90:10), medical-grade silicone rubber and Parylene C. Connection cables consist of individually insulated wires bundled in medical-grade silicone tubing.


Recording and Stimulation

The System is able to record and stimulate with each of the 32 channels.

Stimulation is enabled by current controlled, biphasic, rectangular, asymetric stimulus pulses (cathodic amplitude I with pulsewidth followed by an anodic counter pulse of 1/4x amplitude and 4x  pulsewidth). One current source can be directed to any of the 32 electrodes. The current return path is any of the 32 electrodes or groups of electrodes or an additional counter electrode.


More detailed specifications are available upon request. Please use our contact form to send us you request.


Implanted Device Impedance Measurement

The Brain Interchange System measures the impedance of electrodes on user demand.

Amplifier input impedance
AC Impedance: 15pF capacitance
– 0.1 Hz: 100 GOhm
– 1 Hz: 10 GOhm
– 10 Hz: 1 GOhm
– 100 Hz: 100 MOhm
– 450 Hz: 24 MOhm


Implanted Device Electrode Breakage Detection

The Brain Interchange System ensures patient safety even in case of a broken electrode contact.

Impedance testing identifies defect contacts which will be automacillay excluded from ongoing electrical stimulation treatment. The System requests the user to decide about how to go on for the blocked contacts.

Technical Specifications

Recording channels: 32
Sampling rate:
1 kHz
Sampling dynamic range:
16 bit (74 nV smallest increment)
High pass filter cut-off:
0.1 Hz
Low pass filter cut-off:
450 Hz
Amplifier band pass gain:
Band pass roll-off:
20 dB/dec


Stimulation channels: each of the 32
(concurrent stimulation at 4 channels: 3 predertermined channels, 1 switchable to any of the 32 electrode contacts)
Stimulation type: Current controlled stimulation
Current: Max. -6 mA / +1.5 mA within compliance voltage range of -11V to +5V
Shape: Biphasic, charge balanced
Pulse width: Negative phase: 10 µs – 2,500 µs, Positive phase: 4 times the duration of the negative phase, with 1/4 of the amplitude of the negative pulse


Implant max. power uptake: Typical: < 400 mW
Method of impedance test: Voltage response to current pulse
Thermal monitoring: Protection against overheating
Electrical Isolation of patient from electronics: DC-decoupled using blocking capacitors

Power supply: Wireless inductive, 120-140 kHz
Wireless data transmission: Bi-directional, radio frequency in 2400-2483.5 MHz band

Min. device lifetime: 2 years
Implant size (capsule with coil): 65 mm x 67 mm x 7 mm (max. dimensions)
Surface Area: 7600 mm2
Implant weight: 50-60 g (similar to pacemaker)

External Unit

Application Software, external unit, closed loop, brain interchange system, software


The External Unit consists of the Head Piece which supplies power inductively to the Implanted Internal Electronics Unit and to the Communication Unit. The Implanted Internal Electronics Unit communicates with the External Unit wirelessly through the skin via radio frequency transmission.

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The Implanted Internal Electronics Unit and the Head Piece of the External Unit are aligned through the skin via magnets.


The Communication Unit is typically worn on the upper arm.


The casing of the External Unit is made from biocompatible material, suitable for being in close contact with the skin with a superior level of acceptance for the skin.


The cables connected to the External Unit are lightweight, flexible and have a biocompatible surface material suitable for being in close contact to the skin.


The External Unit exchanges data with the Implanted Internal Electronics Unit and furthermore controls the power supplied to the Head Piece.


It is directly connected to the computer on which the Application Software is controlling the System. The Application Software is communicating to the Implant via the External Unit.


State of the art encrypted communication between the External Unit and Multi-Part-Implant via a RF link.

Technical Specifications

Connection of Communication Unit to Personal Computer with Software Interface: USB 2.0 or 3.0 data transmission

Method of keeping Head Piece unit in place: Suspended by magnets

Maximum power uptake:
Limited by USB 2.0 and USB 3.0 specifications (depends on distances between transmitting and receiving coil)
– USB 2.0 power uptake (~2.5W) for distaces up to 12mm
– USB 3.0 power uptake (~5W) for distances higher than 12 mm

Surface material of Head Piece: PA 2200 (Polyamide 12)

Size of Head Piece: 36,4 mm Ø , Height = 9,3 mm

Weight of Head Piece: 13 g (without cable)

Head Piece cable length: max. 50 cm

ETU Head Piece cable: PUR

Surface material of external relay unit: ABS (UL 94 HB)

Size of Communication Unit: ca. 85 x 95,9 x 48,1 mm3

Weight of Communication Unit: ≤ 300g

Trigger input of Communication Unit: Analog and digital input with adjustable threshold, suitable e.g. for averaging recorded data on a particular trigger signal and synchronization of multiple implant systems

Application Software

Application Software, closed loop, brain interchange system, software


The Application Software runs on a Microsoft Windows 10 Computer and represents the interface between the user and the complete System comprising External Unit and Multi-Part Implant.

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The Application Software provides a graphical user interface.


Additionally, it can visualize implant status data such as impedances, humidity and temperature inside the Hermetic Encapsulation. It is also able to define stimulation signals within the implant’s technical capability and safety limits as well as to execute stimulation commands.

The Software has been developed according to IEC 62304.


The functionality of the Application Software includes visualizing the measured data directly or after the application of a frequency filter (e.g. notch) or storing the data to a local hard disk.


The interface gives access to the complete range of implant functions such as recording, stimulating, impedance testing, etc.


It also enables a safety check of the input stimulation parameters.

Technical Specifications

The PC software is designed for interoperative tests.
Its main features are:

– Live measurement data visualization
– Establish connection to implants
– Error display of implants
– Status display (temperature, humidity, supply voltage)
– Stimulation function editor (graphical editor for complex stimulation patterns)
– Definition of reference electrodes for measurement
– Counter electrode can be selected of any channel incl. ground electrode
– The system is based on an easily extensible signal processing pipeline so that almost any pattern recognition algorithm or closed-loop stimulation paradigm can be implemented
– The system can easily be extended by new components
– Software development according to IEC 62304


Interfaces for implant control on Windows 10 systems

– C++ API (Attention: Compiler must be compatible)
– C API (suitable for integration in Matlab, Labview, etc.)
– Python API (planned)

Brain Interchange research

Please contact us, if you have questions regarding neuroscientific research with the Brain Interchange technology.


With the help of CorTec’s technology neurological diseases and their symptoms can be adressed.

We have compiled some of these together with relevant background information for you.

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CorTec Brain Interchange – Key Aspects of Innovation

Closed-loop system: therapy adjusted to current need
High number of channels: large database
Does not permeate the cerebral tissue: no scarring, advantageous for long-term treatment
No batteries: energy supply via induction
Choice of material and finish made to last: high operational life span

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Through our quality management system, we meet the highest requirements of the applicable standards.

CorTec is DIN EN ISO 13485 certified and has high-class clean rooms.

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