Researchers create a spinal implant to monitor spinal fusion healing
Spinal fusion can treat multiple disorders of the spinal cord. The procedure involves fusing two vertebrae together. Furthermore, surgeons also often use a cage for providing support where the disc was formerly between the vertebrae. However, what if the spine’s healing could be supported in more than one way through those cages?
The researchers at the University of Pittsburgh Swanson School of Engineering are working on creating a patient-specific 3D-printed smart metamaterial implant. The implants will double as sensors for monitoring spinal healing. A detailed paper on their work was published recently in the journal Advanced Function Materials.
Assistant professor of civil and environmental engineering Amir Alavi said real-time biofeedback can be given with the help of a simple implant.
Alavi’s iSMaRT lab led the research. Moreover, Intelligent Structural Monitoring and Response Testing had made another class of multifunctional mechanical materials. They have their own sensors, which record and relay important information. For example, information about pressure and stress on its structure. These meta tribomaterials, also called self-aware materials can generate their own power. In addition, they can be used for multiple sensing and monitoring applications.
The design of the material causes contact electrification between the conductive and dielectric microlayers under pressure. It creates an electric charge that relays information linked with the condition of the material matrix. Moreover, it inherits the outstanding mechanical tunability of regular metamaterials naturally. The power, which is generated through the built-in triboelectric nanogenerator mechanism eliminates the requirement for a separate source of power. Furthermore, a tiny chip is used in recording the data regarding the cage pressure. It is also an important indicator of healing. Additionally, a portable ultrasound can be used for reading the data without any invasive procedures.
The proposed cage senses capabilities uniquely and is also made of material, which is highly tunable. Moreover, it can be customized according to the needs of the patient.
Successful Testing of the Implant
The team tested the device successfully in human cadavers. Moreover, they are looking to move on to animal models after this. And since the material is tunable and scalable to a great extent, the design of the smart sensor can be adapted and applied to various medical devices in the future. For example, cardiovascular stents or components, are used for knee and hip replacements.
The paper was published in Advanced Functional Materials: “Patient-Specific Self-Powered Metamaterial Implants for Detecting Bone Healing Progress”
Developing new and smart medical devices are a need. Especially implants that have novel properties with advance functions. The concept of “self-aware implants” has been proposed here. It will enable the development of a new generation of multifunctional metamaterial devices that can be implanted. Moreover, the devices respond to the environment. In addition to empowering themselves and monitoring their conditions.
All these functions are obtained by integrating nano energy harvesting with mechanical metamaterial paradigms. Moreover, these functions are achieved with the help of nano energy harvests.
Multiple aspects of the concept have been highlighted by the development of proof-of-concept interbody spinal cage implants. Additionally, these implants have self-powering, self-sensing, and mechanical tuning abilities. The bench-top testing is done through synthetic biomimetic and human cadaver spine models. It helps with the evaluation of the electrical and mechanical performance of the patient-specific implants.
The results of the self-aware cage implants show that they can diagnose the process of bone healing. It can be done with the help of signals generated through built-in mechanisms of contact-electrification. The current and voltage generated by the implants under compression forces of spine models reach 9.2V and 4.9 nA. They empower low-power electronics and serve as triboelectric nanogenerators.
The aim of the proposed technology is to make a revolution in implantable devices and to get better surgical outcomes.