The Exciting Future of Electrified Medicine

Within the medical community, the treatment of Parkinson’s Disease (PD) has remained a challenging and unresolved endeavour. The history of PD is extensive; despite being discovered by Dr. James Parkinson over 200 years ago, researchers are yet to find a cure (Goetz, 2011; Rizek, Kumar and Jog, 2016). However, due to advancements in modern-day technologies and strategies, bioelectronic implants have been identified as a viable treatment option for various stages of PD (Rizek, Kumar and Jog, 2016). 

The exact cause of PD is unknown, although many cases are likely consequences of a combination of genetics and exposure to multiple environmental factors (National Institute of Neurological Disorders and Stroke, 2021). Contrarily, some cases are hereditary and can be traced to distinct genetic mutations (National Institute of Neurological Disorders and Stroke, 2021). PD symptoms, such as postural instability and resting tremors are indicative of existing substantial neurological damage; once observed, the harm of these symptoms is irrevocable (Ball, et al., 2019). 

Despite treatment discoveries progressing over the past 200 years, there is no known cure for PD (Lee and Yankee, 2021). Currently, pharmaceutical treatment slows the progression of PD, however, due to the individualized nature of the disorder, the responsiveness of each patient can vary resulting in ineffective treatment of motor problems (Lee and Yankee, 2021). Recently, engineers at Rice University have developed a state-of-the-art, wirelessly charged neural implant to relieve the chronic pain of patients suffering from PD (Williams, 2020). 

The device, a magnetoelectric neural implant (MagNI), operates by first generating an alternating current (AC) magnetic field from its magnetic driver (Yu, et al., 2020). This field is strengthened by an adjacent coil and then converted into AC electric voltage within a magnetoelectric transducer (Yu, et al., 2020). This voltage is then delivered to the spinal implant, replacing the patient’s burning sensation with a more pleasant, buzzing sensation (Yu, et al., 2020). A conceptual diagram of this system is shown in Figure 1. 

Figure 1: Conceptual diagram illustrating the wearable spinal cord microsystem. This device is completely wireless and produces power through the magnetic driver creating an AC magnetic field. The field is raised by passing through a coil and then administered to the implant where it is converted into electric voltage. The resulting voltage allows the patient to mute the aching pain and instead feel a satisfying buzzing feeling to help relieve their pain (Yu, et al., 2020).   

Once the magnetic field is heightened by passage through the coil, it is transferred to the spinal implant, which houses the magnetoelectric transducers (Zaeimbashi, et al., 2021). The magnetic transducer is composed of a millimetre-scale magnetoelectric laminate made up of one nickel-coated lead zirconate titanate layer (PZT) and one Metglas layer coupled with an adhesive non-conductive epoxy (Yu, et al., 2020). These layers exploit ferroic phenomena; the process of converting applied stress into electrical energy (Zaeimbashi, et al., 2021). Due to the mechanical strain created through this thin-film coupling, the two layers are able to transmit and receive electromagnetic waves (Zaeimbashi, et al., 2021). 

This process occurs as the incoming magnetic field alters the physical composition of Metglas, a metal comprised of magnetic grains (Yu, et al., 2020). Once the magnetic field is applied, the grains are shifted and the Metglas changes shape, inducing vibrations that pass to the PZT (Yu, et al., 2020). A voltage is then created in response to mechanical strain (Yu, et al., 2020). This process and a pictorial representation of the magnetoelectric transducer are shown in Figure 2.

Figure 2: Model of a magnetoelectric transducer and the processes that take place within the component. a) depicts the piezoelectric (black) and magnetostrictive Metglas (blue) joined through an Epoxy adhesive. The entire transducer is 0.12mm in height. b) depicts the means by which voltage is created in the transducer. As mechanical stress is applied, the magnetic field is converted into electric voltage in the Metglas and then transferred to PZT which relays this voltage to the implant (Yu, et al., 2020).

This voltage is then transported to the implant where it is converted to a low-frequency current (Mayfield Brain and Spine, 2021). As the current reaches the affected area, it stimulates the nerves, enabling the electrical pulses to modify any pain-induced action potentials from reaching the brain (Mayfield Brain and Spine, 2021). This treatment, unlike pharmacotherapies, does not induce side complications, re-dosing, or therapeutic limitations (Yang and Tolleson, 2017). 

Bioelectronic implants represent a stunning new approach to pain-free life for patients across the world. Although still in early in vivo demonstrations, MagNI can prove to be a very effective treatment option. Electroceuticals, such as MagNI, can usher a new generation of patient care, effectively ending the suffering of individuals diagnosed with chronic conditions.

Works Cited:

Ball, N., Teo, W.P., Chandra, S. and Chapman, J., 2019. Parkinson’s Disease and the Environment. Front Neurol, 10, pp.1–8. 10.3389/fneur.2019.00218.

Goetz, C.G., 2011. The History of Parkinson’s Disease: Early Clinical Descriptions and Neurological Therapies. Cold Spring Harb Perspect Med, 1(1), pp.1–15. 10.1101/cshperspect.a008862.

Lee, T.K. and Yankee, E.L., 2021. A review on Parkinson’s disease treatment. Neuroimmunology and Neuroinflammation, 8, pp.1–23. 10.20517/2347-8659.2020.58.

Mayfield Brain and Spine, 2021. Spinal cord stimulation. [online] Available at: <https://mayfieldclinic.com/pe-stim.htm> [Accessed 20 Sep. 2021].

National Institute of Neurological Disorders and Stroke, 2021. Parkinson’s Disease: Hope Through Research. [online] Available at: <https://www.ninds.nih.gov/Disorders/Patient-Caregiver-Education/Hope-Through-Research/Parkinsons-Disease-Hope-Through-Research> [Accessed 12 Sep. 2021].

Rizek, P., Kumar, N. and Jog, M.S., 2016. An update on the diagnosis and treatment of Parkinson disease. CMAJ, 188(16), pp.1157–1165. 10.1503/cmaj.151179.

Williams, M., 2020. Magnet-controlled bioelectronic implant could relieve pain. [online] Available at: <https://news.rice.edu/2020/02/19/magnet-controlled-bioelectronic-implant-could-relieve-pain/> [Accessed 12 Sep. 2021].

Yang, J.F. and Tolleson, C., 2017. The role of deep brain stimulation in Parkinson’s disease: an overview and update on new developments. Neuropsychiatr Dis Treat., 13, pp.723–732. 10.2147/NDT.S113998.

Yu, Z., Chen, J.C., Alrashdan, F.T., Avants, B.W., He, Y., Singer, A., Robinson, J.T. and Yang, K., 2020. MagNI: A Magnetoelectrically Powered and Controlled Wireless Neurostimulating Implant. IEEE Transactions on Biomedical Circuits and Systems, 14(6), pp.1241–1252. 10.1109/TBCAS.2020.3037862. 

Zaeimbashi, M., Nasrollahpour, M., Khalifa, A., Romano, A., Liang, X., Chen, H., Sun, N., Matyushov, A., Lin, H., Dong, C., Xu, Z., Mittal, A., Martos-Repath, I., Jha, G., Mirchandani, N., Das, D., Onabajo, M., Shrivastava, A., Cash, S. and Sun, N.X., 2021. Ultra-compact dual-band smart NEMS magnetoelectric antennas for simultaneous wireless energy harvesting and magnetic field sensing. Nature Communications, 12(3141), pp.1–11. 10.1038/s41467-021-23256-z.