SBIR-STTR Award

In the field of Neural Prostheses, there is a need for multi-channel recording systems that are implantable under the scalp and that can record from multiple electrodes implanted in human cortex. These systems must have longevity, reliability and high bandwith for recording sharp transient neural activity. Our aim in this proposal is to build on our experience with a 2 channel system, a recently developed eight channel system, and take this to the next level of a 128 channel system, all on the same small footprint. Our specific aims are to (a) design high-density integrated circuit amplifiers for recording biological signals, (b) design a multiplexing system, and (c) fabricate the integrated circuit in the MOSIS foundry and bench test. Longer-term aims are to (i) Incorporate the IC and MUX into our recently completed Hybrid Implantable Electronic Device retaining use of the power induction module, calibration signal and FM transmitters. We would also develop a demultiplexer. (ii) Improve the power induction coil so that it can be used at a distance from the subjects' head or body part containing the power induction receiver coil. This will also involve development of a power amplifier such as an E type amplifier. (iii) Incorporate this IC into LCP based packaging or other substrate and inter-connect technology. (iv) Implant these devices into monkeys after extensive bench testing in preparation for human as well as animal implantation. We expect this effort to eventually result in a recording system that will be the standard for human neural prostheses implantations, thus contributing significantly to the alleviation of human suffering and disability

In the field of cortical control signal acquisition, the recording system is a critical bottleneck for the passage of internal signals to external applications. It is agreed in this field that there are cortical control signals that can be used to control prosthetic devices and restore movement to paralyzed limbs, but these signals must be recorded and transmitted rapidly and intact. It is our goal to complete the development of a wireless, scalable 128-channel recording system, suitable for long-term human use. Applications range from communication for locked-in patients, to environmental control for the disabled, to motion restoration for the spinal cord injury population. Using two recently completed Phase I grants, Neural Signals has the necessary experience to meet this goal. The first Phase I effort (1 R43 NS-42478-01) designed and built an 8-channel, flexible, surface mount assembly, including a wireless inductive power supply, internal calibration, eight recording amplifiers, and eight FM transmitters. The hybrid circuit developed during this grant resulted in a four-fold reduction in the recording system's volume, compared to our previous implantable recording system. The second Phase I grant (1 R43 NS048706-01) has just been completed. During this grant, a 16-channel integrated circuit (1C) was fabricated to amplify signals from cortical electrodes and multiplex the signals using an analog scanner. Specific aims in Phase II are: A: Continue development of the integrated circuit device, (1) by incorporating voltage regulation and bias circuitry into the integrated circuit to minimize external semiconductor components; (2) by improving the floating gate recording amplifier and scanner based on knowledge gained during the Phase I development; (3) by continuing to develop (a) the power induction system and (b) a unique synchronous scanner transmission system that will replace the present FM system. B: Miniaturize the Neurotrophic Electrode connections for reliable connection with the 1C device. C: Choose and implement new coatings and perform soak testing and stress testing of the implantable recording device consisting of the recording amplifiers, power supply, wireless signal transmission and attached electrodes