Concurrent spinal and brain imaging with optically pumped magnetometers.

BACKGROUND: The spinal cord and its interactions with the brain are fundamental for movement control and somatosensation. However, brain and spinal electrophysiology in humans have largely been treated as distinct enterprises, in part due to the relative inaccessibility of the spinal cord. Consequently, there is a dearth of knowledge on human spinal electrophysiology, including the multiple pathologies that affect the spinal cord as well as the brain. NEW METHOD: Here we exploit recent advances in the development of wearable optically pumped magnetometers (OPMs) which can be flexibly arranged to provide coverage of both the spinal cord and the brain in relatively unconstrained environments. This system for magnetospinoencephalography (MSEG) measures both spinal and cortical signals simultaneously by employing custom-made scanning casts. RESULTS: We evidence the utility of such a system by recording spinal and cortical evoked responses to median nerve stimulation at the wrist. MSEG revealed early (10 - 15 ms) and late (>20 ms) responses at the spinal cord, in addition to typical cortical evoked responses (i.e., N20). COMPARISON WITH EXISTING METHODS: Early spinal evoked responses detected were in line with conventional somatosensory evoked potential recordings. CONCLUSION: This MSEG system demonstrates the novel ability for concurrent non-invasive millisecond imaging of brain and spinal cord.

Wireless electrostimulation for cancer treatment: An integrated nanoparticle/coaxial fiber mesh platform.

Cancer, namely breast and prostate cancers, is the leading cause of death in many developed countries. Controlled drug delivery systems are key for the development of new cancer treatment strategies, to improve the effectiveness of chemotherapy and tackle off-target effects. In here, we developed a biomaterials-based wireless electrostimulation system with the potential for controlled and on-demand release of anti-cancer drugs. The system is composed of curcumin-loaded poly(3,4-ethylenedioxythiophene) nanoparticles (CUR/PEDOT NPs), encapsulated inside coaxial poly(glycerol sebacate)/poly(caprolactone) (PGS/PCL) electrospun fibers. First, we show that the PGS/PCL nanofibers are biodegradable, which allows the delivery of NPs closer to the tumoral region, and have good mechanical properties, allowing the prolonged storage of the PEDOT NPs before their gradual release. Next, we demonstrate PEDOT/CUR nanoparticles can release CUR on-demand (65 % of release after applying a potential of -1.5 V for 180 s). Finally, a wireless electrostimulation platform using this NP/fiber system was set up to promote in vitro human prostate cancer cell death. We found a decrease of 67 % decrease in cancer cell viability. Overall, our results show the developed NP/fiber system has the potential to effectively deliver CUR in a highly controlled way to breast and prostate cancer in vitro models. We also show the potential of using wireless electrostimulation of drug-loaded NPs for cancer treatment, while using safe voltages for the human body. We believe our work is a stepping stone for the design and development of biomaterial-based future smarter and more effective delivery systems for anti-cancer therapy.

Biomaterials and bioelectronics for self-powered neurostimulation.

Self-powered neurostimulation via biomaterials and bioelectronics innovation has emerged as a compelling approach to explore, repair, and modulate neural systems. This review examines the application of self-powered bioelectronics for electrical stimulation of both the central and peripheral nervous systems, as well as isolated neurons. Contemporary research has adeptly harnessed biomechanical and biochemical energy from the human body, through various mechanisms such as triboelectricity, piezoelectricity, magnetoelasticity, and biofuel cells, to power these advanced bioelectronics. Notably, these self-powered bioelectronics hold substantial potential for delivering neural stimulations that are customized for the treatment of neurological diseases, facilitation of neural regeneration, and the development of neuroprosthetics. Looking ahead, we expect that the ongoing advancements in biomaterials and bioelectronics will drive the field of self-powered neurostimulation toward the realization of more advanced, closed-loop therapeutic solutions, paving the way for personalized and adaptable neurostimulators in the coming decades.

Comparison of Bipolar and Monopolar Electrode Configurations for FES on Biceps Brachii.

Function electrical stimulation (FES) is recommended as one of the effective methods for rehabilitation of motor function after stroke. There are two forms to deliver electrical stimulation to induce muscle contraction: Bipolar electrode configuration with two electrodes of the same size, and monopolar electrode configuration with a bigger electrode as an indifferent electrode and a smaller one as an active electrode. The purpose of this study is to compare the two kinds of configuration on biceps brachii in terms of induced muscle contraction force and muscle fatigue. In the experiment, electrical stimulation was applied on biceps brachii muscles of the right arm. Isometric contraction was induced by fixing the elbow joint during the stimulation. The experimental results showed that the induced contraction force was bigger using monopolar electrode configuration with the indifferent electrode on the antagonist muscle, and there was no significant difference in muscle fatigue between the configurations. Monopolar electrode configuration with the indifferent electrode on the antagonist muscle was suggested as the most effective method for FES on biceps brachii.Clinical Relevance- This study establishes an effective electrode configuration for FES on biceps brachii.

Enhancing Visual-Guided Motor Imagery Performance via Sensory Threshold Somatosensory Electrical Stimulation Training.

OBJECTIVE: Motor imagery (MI) based brain- computer interface (BCI) has been widely studied as an effective way to enhance motor learning and promote motor recovery. However, the accuracy of MI-BCI heavily depends on whether subjects can perform MI tasks correctly, which largely limits the general application of MI-BCI. To overcome this limitation, a training strategy based on the combination of MI and sensory threshold somatosensory electrical stimulation (MI+st-SES) is proposed in this study. METHODS: Thirty healthy subjects were recruited and randomly divided into SES group and control group. Both groups performed left-hand and right-hand MI tasks in three consecutive blocks. The main difference between two groups lies in the second block, where subjects in SES group received the st-SES during MI tasks whereas the control group performed MI tasks only. RESULTS: The results showed that the SES group had a significant improvement in event-related desynchronization (ERD) of alpha rhythm after the training session of MI+st-SES (left-hand: F(2,27) = 9.98, p<0.01; right-hand: F(2, 27) = 10.43, p<0.01). The classification accuracy between left- and right-hand MI in the SES group was also significantly improved following MI+st-SES training (F(2,27) = 6.46, p<0.01). In contrary, there was no significant difference between the first and third blocks in the control group (F(2,27) = 0.18, p = 0.84). The functional connectivity based on weighted pairwise phase consistency (wPPC) over the sensorimotor area also showed an increase after the MI+st-SES training. CONCLUSION AND SIGNIFICANCE: Our findings indicate that training based on MI+st-SES is a promising way to foster MI performance and assist subjects in achieving efficient BCI control.

A review on magnetic and spintronic neurostimulation: challenges and prospects.

In the treatment of neurodegenerative, sensory and cardiovascular diseases, electrical probes and arrays have shown quite a promising success rate. However, despite the outstanding clinical outcomes, their operation is significantly hindered by non-selective control of electric fields. A promising alternative is micromagnetic stimulation (µMS) due to the high permeability of magnetic field through biological tissues. The induced electric field from the time-varying magnetic field generated by magnetic neurostimulators is used to remotely stimulate neighboring neurons. Due to the spatial asymmetry of the induced electric field, high spatial selectivity of neurostimulation has been realized. Herein, some popular choices of magnetic neurostimulators such as microcoils (µcoils) and spintronic nanodevices are reviewed. The neurostimulator features such as power consumption and resolution (aiming at cellular level) are discussed. In addition, the chronic stability and biocompatibility of these implantable neurostimulator are commented in favor of further translation to clinical settings. Furthermore, magnetic nanoparticles (MNPs), as another invaluable neurostimulation material, has emerged in recent years. Thus, in this review we have also included MNPs as a remote neurostimulation solution that overcomes physical limitations of invasive implants. Overall, this review provides peers with the recent development of ultra-low power, cellular-level, spatially selective magnetic neurostimulators of dimensions within micro- to nano-range for treating chronic neurological disorders. At the end of this review, some potential applications of next generation neuro-devices have also been discussed.

Implantable Electrical Stimulation at Dorsal Root Ganglions Accelerates Osteoporotic Fracture Healing via Calcitonin Gene-Related Peptide.

The neuronal engagement of the peripheral nerve system plays a crucial role in regulating fracture healing, but how to modulate the neuronal activity to enhance fracture healing remains unexploited. Here it is shown that electrical stimulation (ES) directly promotes the biosynthesis and release of calcitonin gene-related peptide (CGRP) by activating Ca2+ /CaMKII/CREB signaling pathway and action potential, respectively. To accelerate rat femoral osteoporotic fracture healing which presents with decline of CGRP, soft electrodes are engineered and they are implanted at L3 and L4 dorsal root ganglions (DRGs). ES delivered at DRGs for the first two weeks after fracture increases CGRP expression in both DRGs and fracture callus. It is also identified that CGRP is indispensable for type-H vessel formation, a biological event coupling angiogenesis and osteogenesis, contributing to ES-enhanced osteoporotic fracture healing. This proof-of-concept study shows for the first time that ES at lumbar DRGs can effectively promote femoral fracture healing, offering an innovative strategy using bioelectronic device to enhance bone regeneration.

Physiologically Self-Regulated, Fully Implantable, Battery-Free System for Peripheral Nerve Restoration.

The long-segment peripheral nerve injury (PNI) represents a global medical challenge, leading to incomplete nerve tissue recovery and unsatisfactory functional reconstruction. However, the current electrical stimulation (ES) apparatuses fail perfect nerve repair due to their inability of the variable synchronous self-regulated function with physiological states. It is urgent to develop an implantable ES platform with physiologically adaptive function to provide instantaneous and nerve-preferred ES. Here, a physiologically self-regulated electrical signal is generated by integrating a novel tribo/piezoelectric hybrid nanogenerator with a nanoporous nerve guide conduit to construct a fully implantable neural electrical stimulation (FI-NES) system. The optimal neural ES parameters completely originate from the body itself and are highly self-responsive to different physiological states. The morphological evaluation, representative protein expression level, and functional reconstruction of the regenerated nerves are conducted to assess the PNI recovery process. Evidence shows that the recovery effect of 15 mm length nerve defects under the guidance of the FI-NES system is significantly close to the autograft. The designed FI-NES system provides an effective method for long-term accelerating the recovery of PNI in vivo and is also appropriate for other tissue injury or neurodegenerative diseases.

Short-term outcomes of different modalities of pyloromyotomy versus gastric electrical stimulation in the treatment of gastroparesis: A systemic review and meta-analysis.

BACKGROUND: The aim of this meta-analysis was to compare the short-term outcomes surrounding the efficacy and complication rate between different modalities of pyloromyotomy and gastric electrical stimulation (GES) in the treatment of gastroparesis. METHODS: Comprehensive, computerized research was performed on PubMed, Embase, and the Cochrane Central Register of Controlled Trials. We additionally reviewed relevant articles, without any language limitations, published prior to April 15, 2020. Meta-analysis was conducted using RevMan 5.3 software. RESULTS: Three studies totaling 196 participants who had received 4 interventions, including single per-oral pyloromyotomy (POP), double POP, laparoscopic pyloromyotomy, and GES, were eligible for analysis. Compared to single POP, double POP achieved a better clinical response with a pooled relative risk (RR) of 1.27 (95% confidence interval [CI], 1.01-1.60, P = .04), while laparoscopic pyloromyotomy and GES showed no difference with a pooled RR of 0.89 (95% CI, 0.74-1.08, P = .23) and 0.87 (95% CI, 0.73-1.04, P = .13), respectively. As for the recurrence and complication rates, only GES showed a borderline significance of recurrence in comparison to single POP (RR 2.17, 95% CI, 1.00-4.71, P = .05), while there were no differences in the remainder of the comparisons. CONCLUSIONS: We conducted a detailed comparison of 3 modalities of pyloromyotomy and GES in the treatment of gastroparesis, with the results suggesting that double POP demonstrated better clinical success with similar recurrence and complication rates. In addition, GES may result in more recurrence amongst these interventions.

Accelerated complete human skin architecture restoration after wounding by nanogenerator-driven electrostimulation.

BACKGROUND: Electrostimulation (ES) therapy for wound healing is limited in clinical use due to barriers such as cumbersome equipment and intermittent delivery of therapy. METHODS: We adapted a human skin xenograft model that can be used to directly examine the nanogenerator-driven ES (NG-ES) effects on human skin in vivo-an essential translational step toward clinical application of the NG-ES technique for wound healing. RESULTS: We show that NG-ES leads to rapid wound closure with complete restoration of normal skin architecture within 7 days compared to more than 30 days in the literature. NG-ES accelerates the inflammatory phase of wound healing with more rapid resolution of neutrophils and macrophages and enhances wound bed perfusion with more robust neovascularization. CONCLUSION: Our results support the translational evaluation and optimization of the NG-ES technology to deliver convenient, efficient wound healing therapy for use in human wounds.

Effects of polarity of bipolar sensorimotor direct cortical stimulation on intraoperative motor evoked potentials.

OBJECTIVE: The present study investigated the effects of the stimulus polarity and location of motor evoked potential (MEP) to establish a stimulation protocol. METHODS: Nineteen patients who intraoperatively underwent MEP in bipolar direct cortical stimulation were enrolled in the present study. Somatosensory evoked potentials (SEP) of the contralateral median nerve stimulation were recorded to determine stimulation sites. MEP was performed under two settings in all patients: 1. Anodal bipolar stimulation: an anode on the precentral gyrus and a cathode on the postcentral gyrus, 2. Cathodal bipolar stimulation: a cathode on the precentral gyrus and an anode on the postcentral gyrus. MEP amplitudes and the coefficient of variation (CV) at a stimulation intensity of 25 mA and the thresholds of induced MEP were compared between the two settings. RESULTS: An electrical stimulation at 25 mA induced a significantly higher amplitude in cathodal bipolar stimulation than in anodal bipolar stimulation. Cathodal bipolar stimulation also showed significantly lower thresholds than anodal stimulation. CV did not significantly differ between the two groups. CONCLUSIONS: These results indicate that cathodal bipolar stimulation is superior to anodal bipolar stimulation for intraoperative MEP monitoring. SIGNIFICANCE: MEP in cathodal bipolar cortical stimulation may be used in a safe and useful evaluation method of motor fiber damage that combines sensitivity and specificity.

Comparison of Monopolar and Bipolar Stimulator Probes for Intraoperative Nerve Mapping During Thyroidectomy: A Prospective Study.

OBJECTIVES/HYPOTHESIS: During intraoperative neuromonitoring in thyroid surgery, two different kinds of stimulator probes, monopolar and bipolar, are commonly used to stimulate the laryngeal nerves. We explore the unique characteristics of both of these probes as they relate to intraoperative laryngeal nerve mapping. METHODS: Twenty-one patients undergoing neuromonitored thyroidectomy by a single surgeon were enrolled. Electromyography (EMG) amplitude and latency measurements were prospectively recorded concurrently from 1 mA stimulation of vagus nerve (VN) and inferior/superior recurrent laryngeal nerve before (with and without fascia) and after thyroid resection using bipolar and monopolar stimulator probes. RESULTS: Significantly higher amplitudes were obtained with monopolar stimulator probes as compared to bipolar probes, in several stimulation scenarios such as at right VN pre-resection (carotid sheath intact), right VN pre-resection (carotid sheath dissected), right VN post-resection and left VN (carotid sheath dissected). No significant differences were found between amplitudes and latency values in all other stimulation scenarios. CONCLUSIONS: According to this study, both probes are reliable and safe for neural mapping. The kind of probe used during neural monitoring is based on surgical situations and surgeon preference. LEVEL OF EVIDENCE: 3 (According to Oxford Centre for Evidence-Based Medicine 2011 Levels of Evidence) Laryngoscope, 131:E2718-E2726, 2021.

Finding New Ways To Treat Tremors.

An estimated ten million people in the United States have a condition known as essential tremor (ET). Yet although it's been recognized for over a century-it was originally known as senile tremor-there is relatively little awareness of it as a distinct medical condition. Sometimes mistaken for Parkinson's disease, ET can lead to shaking of the arms and hands, and sometimes the head or torso. When severe, it can interfere with eating or drinking, writing, dressing, and even make some tasks impossible. Now, new approaches for treating the condition are emerging, potentially offering options to many patients whose life activities have been curtailed by ET.

Transforming absolute value to categorical choice in primate superior colliculus during value-based decision making.

Value-based decision making involves choosing from multiple options with different values. Despite extensive studies on value representation in various brain regions, the neural mechanism for how multiple value options are converted to motor actions remains unclear. To study this, we developed a multi-value foraging task with varying menu of items in non-human primates using eye movements that dissociates value and choice, and conducted electrophysiological recording in the midbrain superior colliculus (SC). SC neurons encoded "absolute" value, independent of available options, during late fixation. In addition, SC neurons also represent value threshold, modulated by available options, different from conventional motor threshold. Electrical stimulation of SC neurons biased choices in a manner predicted by the difference between the value representation and the value threshold. These results reveal a neural mechanism directly transforming absolute values to categorical choices within SC, supporting highly efficient value-based decision making critical for real-world economic behaviors.

A facile and comprehensive algorithm for electrical response identification in mouse retinal ganglion cells.

Retinal prostheses can restore the basic visual function of patients with retinal degeneration, which relies on effective electrical stimulation to evoke the physiological activities of retinal ganglion cells (RGCs). Current electrical stimulation strategies have defects such as unstable effects and insufficient stimulation positions, therefore, it is crucial to determine the optimal pulse parameters for precise and safe electrical stimulation. Biphasic voltages (cathode-first) with a pulse width of 25 ms and different amplitudes were used to ex vivo stimulate RGCs of three wild-type (WT) mice using a commercial microelectrode array (MEA) recording system. An algorithm is developed to automatically realize both spike-sorting and electrical response identification for the spike signals recorded. Measured from three WT mouse retinas, the total numbers of RGC units and responsive RGC units were 1193 and 151, respectively. In addition, the optimal pulse amplitude range for electrical stimulation was determined to be 0.43 V-1.3 V. The processing results of the automatic algorithm we proposed shows high consistency with those using traditional manual processing. We anticipate the new algorithm can not only speed up the elaborate electrophysiological data processing, but also optimize pulse parameters for the electrical stimulation strategy of neural prostheses.

Effects of whole-body neuromuscular electrical stimulation device on hemodynamics, arrhythmia, and sublingual microcirculation.

Neuromuscular electrical stimulation has been used to treat cardiovascular diseases and other types of muscular dysfunction. A novel whole-body neuromuscular electrical stimulation (WB-NMES) wearable device may be beneficial when combined with voluntary exercises. This study aimed to investigate the safety and effects of the WB-NMES on hemodynamics, arrhythmia, and sublingual microcirculation. The study included 19 healthy Japanese volunteers, aged 22-33 years, who were not using any medication. Electrocardiogram (ECG), echocardiography, and blood sampling were conducted before a 20-min WB-NMES session and at 0 and 10 min after termination of WB-NMES. Their tolerable maximum intensity was recorded using numeric rating scale. Arrhythmia was not detected during neuromuscular electrical stimulation or during 10 min of recovery. Blood pressure, heart rate, left ventricular ejection fraction, and diastolic function remained unchanged; however, mild mitral regurgitation was transiently observed during WB-NMES in a single male participant. A decrease in blood glucose and an increase in blood lactate levels were observed, but no changes in blood fluidity, sublingual microcirculation, blood levels of noradrenaline, or oxidative stress were shown. WB-NMES is safe and effective for decreasing blood glucose and increasing blood lactate levels without changing the blood fluidity or microcirculation in healthy people.

Evidence for Subcortical Plasticity after Paired Stimulation from a Wearable Device.

Existing non-invasive stimulation protocols can generate plasticity in the motor cortex and its corticospinal projections; techniques for inducing plasticity in subcortical circuits and alternative descending pathways such as the reticulospinal tract (RST) are less well developed. One possible approach developed by this laboratory pairs electrical muscle stimulation with auditory clicks, using a wearable device to deliver stimuli during normal daily activities. In this study, we applied a variety of electrophysiological assessments to male and female healthy human volunteers during a morning and evening laboratory visit. In the intervening time (∼6 h), subjects wore the stimulation device, receiving three different protocols, in which clicks and stimulation of the biceps muscle were paired at either low or high rate, or delivered at random. Paired stimulation: (1) increased the extent of reaction time shortening by a loud sound (the StartReact effect); (2) decreased the suppression of responses to transcranial magnetic brain stimulation (TMS) following a loud sound; (3) enhanced muscle responses elicited by a TMS coil oriented to induce anterior-posterior (AP) current, but not posterior-anterior (PA) current, in the brain. These measurements have all been suggested to be sensitive to subcortical, possibly reticulospinal, activity. Changes were similar for either of the two paired stimulus rates tested, but absent after unpaired (control) stimulation. Taken together, these results suggest that pairing clicks and muscle stimulation for long periods does indeed induce plasticity in subcortical systems such as the RST.SIGNIFICANCE STATEMENT Subcortical systems such as the reticulospinal tract (RST) are important motor pathways, which can make a significant contribution to functional recovery after cortical damage such as stroke. Here, we measure changes produced after a novel non-invasive stimulation protocol, which uses a wearable device to stimulate for extended periods. We observed changes in electrophysiological measurements consistent with the induction of subcortical plasticity. This protocol may prove an important tool for enhancing motor rehabilitation, in situations where insufficient cortical tissue survives to be a plausible substrate for recovery of function.

Effect of pelvic floor electrical stimulation on diaphragm excursion and rib cage movement during tidal and forceful breathing and coughing in women with stress urinary incontinence: A randomized controlled trial.

BACKGROUND: The pelvic floor muscle (PFM) is associated with respiratory function. We investigated the effects of PFM training by pelvic floor electrical stimulation (PFES) on PFM strength, diaphragm excursion, and upper rib cage movement during tidal and forceful breathing and coughing in women with stress urinary incontinence (SUI). METHODS: In total, 33 participants with SUI were divided into PFES and control groups. The two groups were measured pre- and post-8 weeks of training. Diaphragm excursion and upper rib cage movement during tidal and forceful breathing and coughing and PFM strength were measured using sonography, electromagnetic sensors, and perineometry. RESULTS: There were significant difference of main effect between pre- and post-training and between groups in PFM strength (between groups: P = .001, between time: P < .001) and diaphragm excursion during forceful breathing (between groups: P = .015, between time: P = .026) and coughing (between groups: P = .035, between time: P = .006). There were significant differences in diaphragm excursion during tidal (P = .002) and forceful breathing (P = .005) and coughing (P < .001) between pre- and post-training in the PFES group. Elevation of the upper rib cage during tidal (P < .001) and forceful breathing (P = .001) was significantly decreased after 8 weeks of training in the PFES group. Widening in the horizontal plane in the upper rib cage during forceful breathing (P < .001) was significantly increased after 8 weeks of training in the PFES group. PFM strength (P < .001) was significantly increased after 8 weeks of training in the PFES group. CONCLUSIONS: Pelvic floor muscles training by electrical stimulation can improve diaphragm excursion and breathing patterns in women with SUI.

Discriminability of multiple cutaneous and proprioceptive hand percepts evoked by intraneural stimulation with Utah slanted electrode arrays in human amputees.

BACKGROUND: Electrical stimulation of residual afferent nerve fibers can evoke sensations from a missing limb after amputation, and bionic arms endowed with artificial sensory feedback have been shown to confer functional and psychological benefits. Here we explore the extent to which artificial sensations can be discriminated based on location, quality, and intensity. METHODS: We implanted Utah Slanted Electrode Arrays (USEAs) in the arm nerves of three transradial amputees and delivered electrical stimulation via different electrodes and frequencies to produce sensations on the missing hand with various locations, qualities, and intensities. Participants performed blind discrimination trials to discriminate among these artificial sensations. RESULTS: Participants successfully discriminated cutaneous and proprioceptive sensations ranging in location, quality and intensity. Performance was significantly greater than chance for all discrimination tasks, including discrimination among up to ten different cutaneous location-intensity combinations (15/30 successes, p < 0.0001) and seven different proprioceptive location-intensity combinations (21/40 successes, p < 0.0001). Variations in the site of stimulation within the nerve, via electrode selection, enabled discrimination among up to five locations and qualities (35/35 successes, p < 0.0001). Variations in the stimulation frequency enabled discrimination among four different intensities at the same location (13/20 successes, p < 0.0005). One participant also discriminated among individual stimulation of two different USEA electrodes, simultaneous stimulation on both electrodes, and interleaved stimulation on both electrodes (20/24 successes, p < 0.0001). CONCLUSION: Electrode location, stimulation frequency, and stimulation pattern can be modulated to evoke functionally discriminable sensations with a range of locations, qualities, and intensities. This rich source of artificial sensory feedback may enhance functional performance and embodiment of bionic arms endowed with a sense of touch.

Ease of Application of Various Neuromuscular Devices for Routine Monitoring.

BACKGROUND: Subjective evaluations to confirm recovery from neuromuscular blockade with a peripheral nerve stimulator (PNS) is inadequate. Quantitative monitors are the only reliable method to confirm adequate recovery of neuromuscular function. Unfortunately, many clinicians are unfamiliar with such devices and there is concern that the introduction of objective monitoring would be exceedingly laborious and could cause workflow delays. This study investigates how long it takes experienced nurse anesthetists to apply various neuromuscular devices as well as their perception regarding the ease of application. METHODS: Twenty nurse anesthetists were consented and participated in an educational session that familiarized them with 3 devices: SunStim Plus PNS (SunMed, Grand Rapids, MI), the acceleromyography-based IntelliVue NMT device (Philips, Amsterdam, the Netherlands), and electromyography-based TetraGraph device (Senzime B.V., Uppsala, Sweden). Participants were timed while placing each monitor on patients in a real-world setting. For the quantitative devices (IntelliVue NMT and TetraGraph), participants were also timed when obtaining calibrated baseline train-of-four (TOF) ratios. Friedman test and pairwise Wilcoxon signed-rank tests were used to evaluate the difference in time to connect different devices. Participants were surveyed about how easy they found it to utilize these devices. RESULTS: After adjusting for multiple comparison, time to connect was significantly less for PNS (median, 29; range, 16-58 seconds) compared to either the TetraGraph device (median, 62.8; range, 32-101 seconds; P < .001) or the IntelliVue NMT device (median, 46; range: 28-90 seconds; P < .001). The difference in time to connect between the TetraGraph device and the IntelliVue NMT device was not statistically significant (P = .053), but it took significantly less time to calibrate the TetraGraph device than the IntelliVue NMT device (median difference, -16; range, -88 to 49 seconds; P = .002). The participants found applying either the IntelliVue NMT device (P = .042) or the TetraGraph device (P = .048) more difficult than applying a PNS while finding it easier to calibrate the TetraGraph device versus the IntelliVue NMT device (P < .001). CONCLUSIONS: It takes 19 seconds longer to apply a quantitative neuromuscular monitor (the IntelliVue NMT device) than a PNS. While this difference reached significance, this relatively minimal additional time represents an inappropriate barrier to the application of quantitative monitors. Regardless of which quantitative monitor was utilized, these nurse anesthetists found the application and utilization of such devices relatively straightforward.