Bioelectronics in medicine最新文献

Proteins and peptides possess inherent properties which can benefit medical devices that interact with electro-responsive tissues. However, proteinaceous materials are typically electrically insulating and hence are not suitable to be utilized as conductive elements in electromedical and other bio-interfacing devices. The discovery of intrinsic electrical conductivity in bacterial protein nanofibers, termed e-pili, could give rise to mimetic reductionist design and thus provide an opportunity to improve the function of existing electromedical devices. In this Special Report we review key aspects concerning the properties of e-pili and present the ongoing effort toward the design of mimetic conductive nanostructures. We highlight the advantages of using self-assembling peptides as building blocks for this purpose and discuss the prospect of the envisioned mimetic nanostructures.

The network of peripheral nerves presents extraordinary potential for modulating and/or monitoring the functioning of internal organs or the brain. The degree to which these pathways can be used to influence or observe neural activity patterns will depend greatly on the quality and specificity of the bionic interface. The anatomical organization, which consists of multiple nerve fibers clustered into fascicles within a nerve bundle, presents opportunities and challenges that may necessitate insertion of electrodes into individual fascicles to achieve the specificity that may be required for many clinical applications. This manuscript reviews the current state-of-the-art in bionic intrafascicular interfaces, presents specific concerns for stimulation and recording, describes key implementation considerations and discusses challenges for future designs of bionic intrafascicular interfaces.

Introduction: Electrical nerve block uses electrical waveforms to block action potential propagation.

Materials & methods: Two key features that distinguish electrical nerve block from other nonelectrical means of nerve block: block occurs instantly, typically within 1 s; and block is fully and rapidly reversible (within seconds).

Results: Approaches for achieving electrical nerve block are reviewed, including kilohertz frequency alternating current and charge-balanced polarizing current. We conclude with a discussion of the future directions of electrical nerve block.

Conclusion: Electrical nerve block is an emerging technique that has many significant advantages over other methods of nerve block. This field is still in its infancy, but a significant expansion in the clinical application of this technique is expected in the coming years.

Vagal nerve stimulation is widely used therapeutically but the fiber groups activated are often unknown.

Aim: To establish a simple protocol to define stimulus thresholds for vagal A, B and C fibers.

Methods: The intact left or right cervical vagus was stimulated with 0.1 ms pulses in spontaneously breathing anesthetized rats. Heart and respiratory rate responses to vagal stimulation were recorded. The vagus was subsequently cut distally, and mass action potentials to the same stimuli were recorded.

Results: Stimulating at either 50 Hz for 2 s or 2 Hz for 10 s at experimentally determined strengths revealed A, B and C fiber thresholds that were related to respiratory and heart rate changes.

Conclusion: Our simple protocol discriminates vagal A, B and C fiber thresholds in vivo.