Emerging Medical Technologies and Their Use in Bionic Repair and Human Augmentation

Abstract

As both the proportion of older people and the length of life increases globally, a rise in age-related degenerative diseases, disability, and prolonged dependency is projected. However, more sophisticated biomedical materials, as well as an improved understanding of human disease, is forecast to revolutionize the diagnosis and treatment of conditions ranging from osteoarthritis to Alzheimer's disease as well as impact disease prevention. Another, albeit quieter, revolution is also taking place within society: human augmentation. In this context, humans seek to improve themselves, metamorphosing through self-discipline or more recently, through use of emerging medical technologies, with the goal of transcending aging and mortality. In this review, and in the pursuit of improved medical care following aging, disease, disability, or injury, we first highlight cutting-edge and emerging materials-based neuroprosthetic technologies designed to restore limb or organ function. We highlight the potential for these technologies to be utilized to augment human performance beyond the range of natural performance. We discuss and explore the growing social movement of human augmentation and the idea that it is possible and desirable to use emerging technologies to push the boundaries of what it means to be a healthy human into the realm of superhuman performance and intelligence. This potential future capability is contrasted with limitations in the right-to-repair legislation, which may create challenges for patients. Now is the time for continued discussion of the ethical strategies for research, implementation, and long-term device sustainability or repair.

Keywords: biohacking; brain–machine interface; ethics; exoskeletons; human augmentation; neuroprosthetics.

Figure 1

Brain–machine interface (BMI) design and operation. Electrical or other signals reflecting brain activity are recorded from the scalp, the cortical surface, or within the brain. Magnetoencephalography (MEG) detects magnetic fields created as individual neurons “fire” within the brain, pinpointing the active region within a millimeter and can follow the movement of brain activity as it travels from region to region. Functional magnetic resonance imaging (fMRI) exploits the changes in the magnetic properties of hemoglobin as it carries oxygen. Activation of a part of the brain can increase the ratio of oxyhemoglobin to deoxyhemoglobin. In a similar way to non-invasive EEG, electrocorticography (ECoG) detects and measures the electrical activity of the brain; however, ECoG measurements are taken following direct electrode contact with the cortical surface of the skull. Thus, ECoG has become a tool for detecting brain activity with higher-quality signals to EEG [11]. These signals are analyzed to measure signal features (e.g., single neuron firing rates, amplitudes of EEG rhythms) before their translation into commands that operate applications to replace, restore, enhance, supplement, or improve natural central nervous system outputs [12]. Many commercial ECoG electrode arrays are used clinically and differ in their shape, number of electrodes, spacing, thickness, and materials used. In recent clinical fields, ECoG electrodes are generally implemented for invasive extra-operative monitoring in, for example, patients with drug-resistant epilepsy, and in identifying precise seizure onset zones for resective surgery [13,14]. ECoG’s feasibility is also increasingly being used for rehabilitation purposes in patients with locked-in syndrome, and spinal cord injury [11].

Figure 2

Classification of exoskeletons. Recent research has focused on load augmentation for soldiers/workers, assisting trauma patients, paraplegics, spinal cord injured (SCI) persons and for rehabilitation purposes. For medical exoskeletons, the motion trajectories for individual joints cannot be provided by the wearer as the patient cannot make the required movements. Thus, user interfaces, control strategies, mechanical interfaces, etc., need to be designed specifically to cater for the individualistic needs of the patient. For non-medical exoskeleton applications, the methods for measuring “user intention” are most important; therefore, facilitating actuated mechanisms that support the user’s actions and thus ensuring the desired motions are as natural as possible, is the key objective. HAL: Hybrid Assistive Leg, CHRIS: Cybernetic Human–Robot Interface System, BLEEX: Berkeley Lower Extremity Exoskeleton, MIT: Massachusetts Institute of Technology, SCI: spinal cord injury [108,128,129,130,132,133,141,142,143,144,145,146,147,148,149,150,151,152,153,154,155,156,157].

Figure 3

(A) The first retinal implant (ARGUS I) was developed in 2002, and later, ARGUS II^® received FDA approval in 2013. Presently, Retina Implant Alpha IMS^® has undergone clinical trials; the PRIMA bionic vision system, the IRIS V2 and Suprachoroidal Retinal Prosthesis have also been tested in human studies. The EPI-RET3, Subretinal Retinal Prosthesis and the fully organic P3HT prosthesis are more recent devices that have been studied using pre-clinical models only. (B) The P3HT retinal polymer prosthetic is biocompatible and can cause strong neural responses in the same way as when naturally responding to impulses from rods or cones. This light-sensitive implant material is able to extend the wavelength over which an animal is able to detect light as well as improve visual acuity in rodents. Although proven to be efficient, the working mechanism is not fully understood [198].

Figure 4

Biohacking can be as simple as changing your diet, listening to music, and taking supplements, to trying to change your gut microbiome, gene therapy, or methods to modify genetic or brain function to improve one’s self (faster, stronger, mitigating a predisposition for a disease, better focus, memory, energy, etc.) It also refers to devices that may extend or improve human capabilities to enhance the human condition such as exoskeletons and implantable biosensors.

Figure 5

The promise of implantable, wearable, and genetic technology for improving human health, wellbeing, and performance has never been greater. However, novel smart technologies that are able to biointerface with the body and/or society, raises social, ethical, and environmental issues. As this field continues to progress and their use becomes increasingly inseparable from the human world, the implementation of strategies that address these issues are needed.