A battery-free and smart implant in the spine was made by an Iranian scientist

Joint collaboration between civil engineering and neurosurgery at the University of Pittsburgh It could change the way spinal fusion surgery is performed and monitored. Amir Alavi, Nitin Agarwal, and D. Cujo Hamilton have received a $352,000 grant from the National Institutes of Health. Their goal is to develop the first self-feeding spinal implant capable of transmitting real-time data from inside the body.

According to the medical technology department of Tecna news media, this interdisciplinary project can make the recovery after spinal fusion surgery safer by providing the possibility of remote tracking of the patient’s progress by doctors. This monitoring allows doctors to intervene before complications occur. About one million Americans undergo spinal fusion surgery each year, in which a metal cage and bone graft are used to connect two vertebrae in the spine.

Agarwal, one of the project’s principal investigators, explained that the implanted hardware is currently monitored through X-rays and patient-reported symptoms. This approach requires patients to visit in person and expose them to radiation. He added that because doctors and patients can’t easily monitor the spine’s healing process, there isn’t a seamless healthcare experience.

Although implantable wireless devices that monitor medical procedures are becoming more common, these devices require batteries and electronic components to transmit signals. This dependence makes them not permanent and have a limited lifespan. Amir Alavi, the main researcher of this project, turned to an unexpected field to find a better solution. He used technology he had previously developed to monitor bridge infrastructure.

During his PhD, Alavi built sensors that generate their own energy and send signals about changes in the physical properties of bridges. These sensors alert authorities to structural weaknesses before more serious damage occurs. Alavi found that this technology could also be adapted to work on a patient’s spine.

He explained that this new system has no batteries, antennas or electronics inside the body. By combining metamaterial design and nano energy harvesting, implants have been made completely without batteries and electronics. These implants supply their energy through electrical contact. They are adapted to each patient and transmit signals wirelessly like a small router inside the body.

Using new man-made composites known as metamaterials, Alavi’s team has created structures consisting of single cells of different sizes. By interweaving conductive and non-conductive materials, they optimize these structures for energy harvesting and signal transmission when pressure is applied. This unexpected collaboration began in 2023 to integrate this technology into medical implants.

Alavi stated that they are making cages for spinal fusion surgery that have natural and internal intelligence like human cells. These cages are placed between two vertebrae and while providing stability, they also monitor the healing process. If the spine is healing, the bone will start to bear more load and the signal generated by the implant will naturally decrease.

He noted that the signal is stronger immediately after surgery because the vertebral endplates exert more pressure on the cage, resulting in more energy being generated. These signals are received through an electrode on the patient’s back and transmitted to the cloud. Real-time analysis of these signals allows medical intervention before more serious damage occurs.

Alavi also used generative artificial intelligence to generate unique metamaterial designs for each patient’s spine, speeding up the process dramatically. His team can scan the patient’s spine and then design and print the cage to fit perfectly. This metamaterial system has complete control over stiffness and more importantly the ability to generate energy.

Researchers are now working on using this energy for electrical stimulation as well. Alavi and Agarwal have tested these cages in a lab setting and the technology works well. With the support of the National Institute of Health, this team will conduct in vivo experiments using animal models. Agarwal stated that if successful, the next step would be human testing.