Center for Implantable Devices at the Weldon School for Biomedical Engineering

Professor Pedro Irazoqui of the Weldon School of Biomedical Engineering is leading the launch of a new Research Center for Implantable Devices (CID) at Purdue University.

The Mission

The new Center's mission is to lead the research, development, and translation of implantable medical devices; to formalize collaborations between faculty, clinicians and commercial partners; and to maximize clinical impact. The Center takes a modular approach to the design of biological implants in general, and neural prosthetic devices in particular. Module types include those for:

  • Sensing biological activity
  • Actuating a cellular or system response
  • Transmitting and receiving data
  • Powering the system of modules

Systems comprised of sensing, actuating, transmitting and powering modules, combined into distinct, application-specific devices, enable researchers and clinicians the maximum flexibility in conducting meaningful and hereto impracticable experiments. These systems also develop novel avenues for the treatment of neural disorders through miniature, wireless, electronic prostheses. The important parameters and trade-offs in the design of the individual modules, their integration into functioning systems, and the manner in which they interface both with the biology and the external world are examined both in theory and in practice, with a variety of real-world devices as examples. Specific research and clinical applications being explored include: epilepsy, Parkinson’s disease, and both retinal and motor prosthetics.

The People

Founding faculty members include Pedro Irazoqui (Weldon School of Biomedical Engineering), William Chappell (School of Electrical & Computer Engineering and Weldon School of Biomedical Engineering), Kaushik Roy (School of Electrical & Computer Engineering) and Jenna Rickus (Weldon School of Biomedical Engineering and Agricultural & Biological Engineering). Clinicians involved in the new Center include Robert Worth (Indiana University School of Medicine), Todd Kuiken (Rehabilitation Institute of Chicago), Art Coffey (Methodist Hospital, Indianapolis), Robert Berger (Beth Israel Deaconess Medical Center, Boston) and Gabriel Simon (Instituto Gabriel Simón, Barcelona).

The Center for Implantable Devices is partnering with several companies on their projects, including Cyberonics, Inc. for an epilepsy prosthesis, EpiMon, Inc. on chronic pre-surgical monitoring, Blackrock Microsystems, Inc. on brain-computer interfaces, SenSor, Inc. for congestive heart failure and pulmonary arterial hypertension, and SOLX, Inc. for glaucoma.

Major Ongoing Projects


Every five minutes, a child is diagnosed with epilepsy. 1% of all people, throughout history, have suffered from epilepsy. There is a ~25% chance of developing epilepsy post-traumatic brain injury.Epilepsy affects more than 50 million people worldwide, of which 30-40% do not respond to current drug treatment. The gross features of epilepsy are broadly known, but the nuances of its workings, its development, and its natural triggers remain largely obscure. Causes of epilepsy could include genetics, head trauma, and disease.

The Center for Implantable Devices is developing anapplication-specific integrated circuit (ASIC) for a cell-based therapy with closed-loop control to provide seizure-induced GABA release from a renewable source.This therapy will be engineered as a hybrid cellular-silicon neural implant device.


5.7 million U.S. patients, and 15 million worldwide suffer incidences of congestive heart failure (CHF) or pulmonary arterial hypertension (PAH), accounting for 5% of all hospital admissions. The mortality rate after diagnosis is 30-40% in one year, and 60-70% in five years.

Researchers in the Center for Implantable Devices have designed and built the first active pressure monitor that is wireless and implantable for closed-loop treatment. This system will monitor available drugs, devices or surgical intervention 24/7. Its components include a micro-sensor (MEMS), capacitive power storage array, integrated circuit, monopole antenna, remote data receiver (POD) assembled in a biocompatible liquid crystal polymer-based package. This device allows continuous, remote monitoring of pressure automatically, remote updates can be sent to physician regarding condition, and the take-home receiver can be placed on bed stand for automatic recharging, data transmission, and uploading to secure database


Glaucoma is a detrimental disease that causes blindness. Current estimates anticipate that the number of glaucoma patients worldwide will rise from 45 million to 100 million by 2020. There are numerous treatments to slow the condition but none are totally effective and all have significant side effects. Currently, a continuous monitoring device is not available, but its development may open up new avenues for treatment.

Efforts by CID researchers focus on the design and fabrication of an active glaucoma intraocular pressure (IOP) monitor that is fully wireless and implantable. Major benefits of an active IOP monitoring device include the potential to operate independently from an external device for extended periods of time and the possibility of developing a closed-loop monitoring and treatment system. The fully wireless operation is based off using gigahertz- frequency electromagnetic wave propagation, which allows for an orientation independent transfer of power and data over reasonable distances. Our system is comprised of a microelectromechanical system (MEMS) capacitive sensor, a capacitive power storage array, an application specific integrated circuit (ASIC) designed on the Texas Instruments (TI) 130 nm process, and a monopole antenna all assembled into a biocompatible liquid crystal polymer (LCP) based tadpole-shaped package.

Neural Interfaces

Networked, magnetically inserted, stimulating and recording electrodes: Chronic recording and stimulating electrodes are a vital tool for brain research and neural prostheses. Despite decades of advances in recording technology, probe structures and implantation methods have changed little over time. Then as now, compressive insertion methods require probes to be constructed from hard, stiff materials, such as silicon, and contain a large diameter shank to penetrate the brain, particularly for deeper structures. The chronic presence of these probes results in an electrically isolating glial scar, degrading signal quality over time. This research project demonstrates a new magnetic tension-based insertion mechanism that allows for the use of soft, flexible, and thinner probe materials, overcoming the materials limitations of modern electrodes.

Injectable EMG sensing from reinnervated muscle for prosthesis control: Working in collaboration with Dr. Todd Kuiken, Director of the Neural Engineering Center, Rehabilitation Institute of Chicago, CID researchers are working on the development of an FDA-approved, clinically usable, chronically implantable wireless EMG recording system for demonstration and use in people with amputations. The implantable EMG system will be based on the latest low power radio frequency (RF) technology. This will facilitate reliable, long-term, stable recording of EMG signals and further improvements in prosthesis control.

Implantable LED optrodres for stimulating rhodopsin expressing neurons: A new wireless implant, combined with a magnetically inserted 25 µm fiber optic can be used to stimulate neurons optically with tremendous precision. In collaboration with Prof. Jenna Rickus, CID researchers are beginning to use two new technologies developed in her lab to better understand the effect of various forms of electrical stimulation on the central nervous system in general and epilepsy in particular. This will allow an unprecedented level of examination and understanding of the workings of neural stimulation in deep-brain and cranial nerve applications.

For more information, visit the CID website