The cuff electrode can be wrapped in the columnar or tubular biological tissue for physiological signal detection or stimulation regulation. The reliable and non-excessive interfaces between the electrode and complex tissue are critical. Here, we propose a self-closing stretchable cuff electrode, which is able to self-close onto the bundles of tissues after dropping water. The curliness is realized by the mechanical stress mismatch between different layers of the elastic substrate. The material of the substrate can be selected to match the modulus of the target tissue to achieve minimal constraint on the tissue. Moreover, the self-closing structure keeps the cuff electrode free from any extra mechanical locking structure. For in vivo testing, both sciatic nerve stimulation to drive muscles and electromyographic signal monitoring around a rat\'s extensor digitorum longus for 1 month prove that our proposed electrode conforms well to the curved surface of biological tissue.

UNASSIGNED: To verify the safety and effectiveness of a novel micro-implantable wireless nerve stimulation device in healthy adult beagles and evaluate the feasibility of using the device in clinical practice.
UNASSIGNED: The stimulator was experimentally implanted into the quadriceps femoris of three adult beagles. The animals were subjected to training on daily basis for 14 days, and the threshold test was administered once a week. At the end, we analyzed the images of light microscopy and electron microscopy.
UNASSIGNED: The implantation was easy to perform and the whole stimulation system worked stably and reliably. The stimulation threshold was stable. During the process, the stimulator did not move or cause damage to adjacent tissues. The whole system showed a good biocompatibility with recipient animals. The stimulator could induce muscular contraction and enhance the motor function of muscles.
UNASSIGNED: The preliminary results showed that the stimulator could be safely implanted into animal body, with good tissue compatibility, stability and reliability. In addition, it also worked well in eliciting muscle contraction. It promises to be used for the treatment of stress urinary incontinence in future.

Nerve cuff electrodes have been used for decades as peripheral nerve interfacing devices in the fields of neural science, neural disease, and brain-machine interfacing. The currently-used cuff electrode is commonly based on rigid materials whose flexibility and tensile properties are far different from those of biological nervous tissue. Herein, a fluidic cuff electrode using a gallium-based liquid metal (LM) conductor is developed as a prototype artificial peripheral nerve. The results indicate that the LM cuff electrode has high flexibility and maintains outstanding conductivity. After implanted and connected to the sciatic nerve, the LM electrodes within the freely moving rats\' bodies survive repeated body stretching and retain their long-term effectiveness in transmitting sciatic nerve signals with a high signal-to-noise ratio during two-week experiments. The LM electrodes are also proven capable of transmitting neural stimuli to the peripheral nerve on a long-term basis by triggering clear event-related potentials (ERPs) in terms of both the cortical potential and sciatic signal. These tests demonstrate that the LM electrodes meet the requirements of peripheral nerve signal recording and stimulation for long-term implantation, and have the potential to become a new generation of artificial peripheral nerve devices to interface with, supplement, or even enhance and replace the real peripheral nerve.

Spinal cord injury (SCI) is a devastating and common neurological disorder that is difficult to treat. The pain can sustain for many years, making the sufferer extremely painful. Nerve stimulation was first reported half a century ago as a treatment for neuropathic pain. Since then, the method of electrical stimulation through leads placed in the epidural space on the dorsal side of the spinal cord has become a valuable therapeutic tool for SCI. But nerve stimulation equipment is expensive, and the stimulator design and treatment plan are complicated, which hinders its development. In recent years, wearable and implantable triboelectric nanogenerators (TENGs) developed rapidly, and their low cost and safety have brought a new turning point for the development of nerve stimulation. Nanofibrous membrane has been proved that it is a flexible material with the advantages of ultrathin diameter, good connectivity, easy scale-up, tunable wettability, fine flexibility, tunable porosity, controllable composition and so on. In this paper, we discuss the technology of using nanofiber membrane on clothing to create TENGs to provide continuous electrical energy for nerve stimulation to treat SCI in patients by analyzing previous research.

Patients with lower limb fracture often have acute pain and discomfort from changes in position, and such pain affects early postoperative recovery. This study aimed to compare the applicability and effectiveness of ultrasound combined with nerve stimulator-guided lumbosacral plexus block (LSPB) in the supine versus lateral position during lower limb fracture surgery.
We included 126 patients who underwent elective internal fixation for lower limb fracture who were divided into the S group and the L group by the random number table method and underwent LSPB guided by ultrasound combined with a nerve stimulator in the supine and lateral positions, respectively. The primary outcome was the dose of sufentanil used in surgery. The secondary outcomes were the maximum VAS (visual analogue scale) pain score at position placing for LSPB, the time of position placing, the time for nerve block,the number of puncture attempts,the haemodynamic indicators, the VAS score at 1, 12, and 24 h following surgery, postoperative satisfactory degree to analgesia and adverse events related to nerve block.
There was no statistically significant difference in dose of sufentanil used between the two groups(P = 0.142). The maximum VAS pain score at position placing(P < 0.01), the time of position placement(P < 0.01), the time for lumbar plexus block and the time of puncture attempts were significantly lower in the S group than in the L group (P < 0.01). However, the time for sacral plexus block was higher in the S group than in the L group (P = 0.029). There was no significant difference in haemodynamic indicators,number of puncture attempts for the sacral plexus, postoperative VAS scores, postoperative satisfactory degree to analgesia or adverse events related to nerve block between the two groups (all P > 0.05).
Our study provides a more comfortable and better accepted anaesthetic regimen for patients undergoing lower limb fracture surgery. LSPB in the supine position is simple to apply and has definite anaesthetic effects. Additionally, it has a high level of postoperative analgesia and therefore should be widely applied.
The trial was registered prior to patient enrolment at the Chinese Clinical Trail Registry (Date:11/03/2021 Number: ChiCTR2100044117 ).

Implantable biomedical devices (IMDs) play essential roles in healthcare. Subject to the limited battery life, IMDs cannot achieve long-term in situ monitoring, diagnosis, and treatment. The proposal and rapid development of triboelectric nanogenerators free IMDs from the shackles of batteries and spawn a self-powered healthcare system. This review aims to overview the development of IMDs based on triboelectric nanogenerators, divided into self-powered biosensors, in vivo energy harvesting devices, and direct electrical stimulation therapy devices. Meanwhile, future challenges and opportunities are discussed according to the development requirements of current-level self-powered IMDs to enhance output performance, develop advanced triboelectric nanogenerators with multifunctional materials, and self-driven close-looped diagnosis and treatment systems.

OBJECTIVE: Nerve stimulation and neuromodulation have become acceptable interventions for bladder dysfunction. However, electrical stimulation indiscriminately affects all types of cells and can lead to treatment failure and off-target effects. In recent years, advancement of knowledge of optogenetics provides a powerful tool to enable precise, minimally invasive neuromodulation.
METHODS: In this review, we introduce basic knowledge about optogenetics; discuss the progression of engineered opsins, gene-targeting methods, and light-delivery approaches; we also summarize the application of optogenetics in neuromodulation of the bladder and discuss the possible clinical translation in the future.
CONCLUSIONS: Optogenetics offers a powerful tool to investigate the neural circuit of bladder storage and voiding and provides a promising approach for manipulating neurons and muscles. It is possible to achieve coordinated modulation of the bladder and its sphincter through a \"closed-loop\" system. Optogenetics neuromodulation could also be applied in urinary bladder control in the clinic in the future.

Electrical stimulation of peripheral nerves by implanted electrodes is an effective treatment for certain pelvic floor diseases. As well as intravesical electrical stimulation, this predominantly includes stimulation of the sacral nerve, tibial nerve, and pudendal nerve. The pudendal nerve is one of the main nerves that stimulate pelvic floor muscles, external urethral meatus, and the anal sphincter and pelvic organs, and it may have effects on frequent urination, urgency, dysuria, and perineal pain. It is difficult to locate because of its anatomical course, however, leading to difficulties fixing the electrode, which increases the difficulty of pudendal nerve electrical stimulation in clinical practice. In the current study 3D printed navigation was used to solve these problems. Combined with autopsy data and patient pelvic and nerve data, a personalized design was generated. Neural modulation of the pudendal nerve was achieved by implanting the lead with the guidance of 3D printed navigation. 3D printed navigation can maximize the phase II conversion rate, reduce the difficulty of surgery, shorten the operation time, reduce damage to additional organs and blood vessels, and increase the accuracy of electrode implantation, and it can be performed while the patient is awake. It is an accurate, reversible, efficient, and minimally invasive surgery.

Sepsis is a serious medical condition in which immune dysfunction plays a key role. Previous treatments focused on chemotherapy to control immune function; however, a recognized effective compound or treatment has yet to be developed. Recent advances indicate that a neuromodulation approach with nerve stimulation allows developing a therapeutic strategy to control inflammation and improve organ functions in sepsis. As a quick, non-invasive technique of peripheral nerve stimulation, acupuncture has emerged as a promising therapy to provide significant advantages for immunomodulation in acute inflammation. Acupuncture obtains its regulatory effect by activating the somatic-autonomic-immune reflexes, including the somatic-sympathetic-splenic reflex, the somatic-sympathetic-adrenal reflex, the somatic-vagal-splenic reflex and the somatic-vagal-adrenal reflex, which produces a systemic effect. The peripheral nerve stimulation also induces local reflexes such as the somatic-sympathetic-lung-reflex, which then produces local effects. These mechanisms offer scientific guidance to design acupuncture protocols for immunomodulation and inflammation control, leading to an evidence-based comprehensive therapy recommendation.

A nerve stimulation-guided lumbar plexus block is a well-established technique. It is not clear whether ultrasound guidance has additional value for this deep block technique. This study aimed to examine whether ultrasound guidance using a paramedian transverse scan through the intertransverse space (PMTS-ITS) approach in combination with nerve stimulation reduces the onset time of a complete sensory block. Forty-four patients who were scheduled to undergo arthroscopic knee surgery with an ultrasound visibility score (UVS) of ≥10 for the lumbar plexus were enrolled and randomly allocated to the ultrasound guidance with nerve stimulation group (group U-N) or nerve stimulation group (group N) in this prospective, randomized, parallel-group, active-controlled study. The primary outcome was the onset time of a complete sensory block. The results showed that the onset time of a complete sensory block to pinprick and cold was 10 (10-40) min and 10 (10-40) min in group U-N, respectively, and 30 (10-40) min and 20 (10-40) min in group N (P=0.005, P=0.004), respectively. The performance time was 658±87 s in group U-N and 528±97 s in group N (P<0.001). There was no (0%) patient who required 5 or more needle passes in group U-N and 6 (27.3%) in group N (P=0.028). The block failure rate was 9.1% in group U-N and 31.8% in group N (P>0.05). In conclusion, ultrasound guidance using the PMTS-ITS approach in combination with nerve stimulation led to a faster onset of a complete sensory block than nerve stimulation alone for a lumbar plexus block in patients with a UVS ≥10. Ultrasound guidance with nerve stimulation significantly decreased the number of patients who required 5 or more needle passes.