Osseosurface electronics
One emerging application of implantable wireless sensors is osseosurface electronics, an implementation in which wireless sensing devices are implanted and adhered directly to bone surfaces [168]. These battery-free devices are equipped with multimodal capabilities, including sensors for real-time bone strain measurement, millikelvin resolution thermography, and optical stimulation. They operate wirelessly through energy harvesting and data transmission, eliminating the need for internal batteries. The devices are permanently bonded to the bone using calcium phosphate ceramic particles, demonstrating stable integration and functionality in deep tissue environments. The system features a hybrid integration of a flexible substrate with miniaturized components for analog and digital functions, enabling conformal attachment to the bone while maintaining stability and minimizing strain on the target sensing region. The device utilizes magnetic resonant coupling (13.56 MHz) for wireless, battery-free power harvesting through thick tissues up to 11.5 cm. The system operates using NFC-compatible hardware, featuring a compact NFC system-on-chip (4 mm × 4 mm) that integrates a microcontroller and transponder for operational control (Fig. 7A). The analog front-ends (AFE) for strain and temperature sensing are optimized for low power consumption and high sensitivity.
https://link.springer.com/article/10.1007/s44258-024-00041-3#citeas

Technologies and applications in wireless biosensors for real-time health monitoring

Published: 25 November 2024
Xu, Z., Hao, Y., Luo, A. et al. Technologies and applications in wireless biosensors for real-time health monitoring. Med-X 2, 24 (2024). https://doi.org/10.1007/s44258-024-00041-3

Implantable Sensors:
Wireless implantable, ingestible, or digestible biosensors allow for rigorous biophysical and biochemical monitoring, enabling real-time closed-loop interventions through in vivo measurements and continuous physiological detection [166]. Several biomedical applications exist for implantable sensors, ranging from neurological to gastroenterological pathways [167].

Technical and Feasibility Analysis

• Power Discrepancy: WBAN energy harvesting devices are designed to generate minute amounts of power, typically in the milliwatt range, which is just enough to power low-energy medical sensors or recharge small internal batteries. In contrast, a single modern Bitcoin mining machine (ASIC) consumes thousands of watts (kilowatts) of power, an amount equivalent to several households.

• Energy Sources: The energy sources used for WBANs are typically body movements (kinetic) or body heat (thermal), which are low-density and highly variable.

• Computational Intensity: Cryptocurrency mining, particularly for Proof-of-Work systems like Bitcoin, relies on immense computational effort and the associated massive energy consumption to solve complex mathematical problems. The limited energy from WBANs cannot power the specialized, high-performance hardware needed for this task.

Related Concepts:
While direct energy harvesting for standard crypto mining is not practical, some related concepts have been explored in research and art projects:

• Proof-of-Activity Patents: A Microsoft patent application from 2020 described a theoretical system where human body activity (like brain waves or body heat emitted when performing a task such as viewing an advertisement) could be used as "proof-of-work" to verify data and earn cryptocurrency, rather than using traditional intensive computation. This system uses the data of activity as proof, not the energy itself to power the computational process.

• Art Projects: An art project by the Dutch "Institute of Human Obsolescence" (IoHO) in 2018 used special suits to capture the body heat from 37 people to power a small computer that mined a negligible amount of cryptocurrency over several hours. This was primarily a symbolic project to highlight the link between human labor and data production.

In summary, the power available from WBANs is fundamentally insufficient for the energy demands of cryptocurrency mining.

Performance Evaluation of Magnetic Resonance Coupling Method for Intra-Body Network (IBNet)
[I do not have the full document on this one.] THEORETICAL RESEEARCH!

Spurred by the advances in ultra-low-power electronics and communications, emerging implantable medical devices have led to new insights into long-term and continuous healthcare monitoring. For effective management of such medical devices, the intrabody network (IBNet) is becoming increasingly important. However, traditional means of intra-body communication (e.g., galvanic, capacitive, RF) are often affected by significant path loss due to tissue absorption, shadowing effect, environmental variations, instability of transmission quality, grounding issues, antenna size, etc. In pursuit of more suitable technology for the IBNet, the magnetic resonance (MR) coupling arose a great interest in the community since the magnetic permeability of the biological tissue is similar to that of the air, absence of an external reference or ground, and near-field operation.

In this paper, we present magnetic resonance (MR) coupling as a promising method for the intra-body network (IBNet). With seven healthy human subjects, we systematically compared MR coupling to traditional intra-body communication methods (galvanic, capacitive, and RF). The study revealed that MR coupling could effectively send or receive signals (power/data) in biological tissue, with a maximum path loss (P­L) less than 33 dB (i.e., at 13.56 MHz). Such path loss was lower than galvanic, capacitive, or RF couplings for the same distance. The angular orientation between the transmitter and the receiver coils showed minor variation in the path loss (0.19 ≤ ∆PL ≤ 0.62 dB) but observed some dependency on the distance (0.05 dB/cm). Different postures during the MR coupling essentially did not affect performance (∆PL ≤ 0.21 dB). The multi-nodal transmission between a single transmitter and multiple receivers showed that the signal could be simultaneously delivered, demonstrating a potential for communication, sensing, and powering wearable and implantable devices. Overall, the MR coupling conserves energy for long-term implants by enabling low-power communication at lower path loss in the human body. https://www.embs.org/featured-articles/performance-evaluation-of-magnetic-resonance-coupling-method-for-intra-body-network-ibnet/

Magnetic Resonance Coupling for Intra Body Network (1BNet)
Mining your body's energy for Crypto Currency? [THEORETICAL]