Vibratory Stimuli Research Articles

Effects of wearing personal protective equipments during work on health problems and injuries of workers exposed to vibration stimuli: the fifth Korean working condition survey

Objective: The purpose of this study was to identify the effects of wearing personal protective equipment (PPE) during work on the health problems and injuries of workers exposed to vibration stimuli. Method: We used data from the fifth Korean Working Condition Survey (2017). After applying the inclusion and exclusion criteria, 3,062 workers were included. The occurrence of health problems and injuries was investigated using a self-reported questionnaire. Chi-squared tests were used to compare the differences in baseline characteristics between the groups wearing and not wearing PPE. The odds ratios and 95 % confidence intervals were estimated using a multivariate logistic regression model adjusted for several covariates. Results: As a result of multivariate logistic regression analysis, the probability of back pain was 1.379 times higher in the group not wearing PPE than in the group wearing PPE (OR =1.379, 95 % CI: 1.031 - 1.845). Additionally, the likelihood of headaches and eye fatigue was 1.651 times higher (OR = 1.651, 95 % CI: 1.228 - 2.220). Conclusion: We found that wearing PPE could reduce the risk of back pain, headaches, and eye fatigue due to exposure to vibration stimuli between tasks. These results can contribute to improvements in the working environment and the health promotion of workers as a basis for practical educational data to improve the PPE-wearing rate.

Vascularizing action of the compressive microvibration endospheres

The aging processes of the face and body are mainly linked to the cellular characteristics referred to the lower use of oxygen and reduced mitochondrial activity with tissue purification deficiency and activation of inflammatory or degenerative processes that lead to fibrosis and to female evolutive fibroadenoma, so-called cellulite. All medical and aesthetic methods are today aimed, first of all, at improving tissue vascularization with an increase in temperature and consequent activation of metabolic activities, reducing inflammatory and regenerative processes. Compressive Microvibration Endosphères uses 55 rotating microspheres to create particular vibratory stimuli on the energy points and on the tissues in order to obtain optimal functional responses to vascularize, drain and regenerate, finally to reduce the pain of the tissues with fibroadenoma and lymphatic stasis. In 2007, the preliminary studies of this method were presented; since then and up to now, there have been interesting studies and clinical experiences that show a constant and typical vascularizing action and thermal tissue increase that opens interesting reflections about the relationship between microvibration and vascularization. In light of current scientific knowledge, the retrospective study is the aim of this work.

Effects of vibrotactile-enhanced music-based intervention on sensorimotor control capacity in the hand of an aging brain: a pilot feasibility randomized crossover trial

BackgroundMusic-based interventions (MBI), using music as a therapeutic medium, has been utilized as a promising strategy for motor relearning and shaping. However, currently, MBI with active performance training is restricted to being extensively applied for patients with various levels of defects in fine motor skills and cognitive functions. Therefore, the integration of vibrotactile stimulation with MBI has been adopted as a motor training strategy intended to enhance motor learning through use of vibration stimuli. The current study was designed to investigate differences in the sensorimotor performance of older adults’ hands under baseline, a single session of active MBI, and vibrotactile-enriched MBI conditions.MethodsThirty healthy older adults were recruited and randomized to receive either the single session of 30-min of vibrotactile-enriched MBI or 30-min of active MBI at the beginning of the experiment. After a one-week washout period, they switched their treatment programs and then were assessed to study the training effects of both approaches through measuring precision pinch performance, hand function, and sensory status.ResultsThe results of the Pinch-Holding-Up Activity test revealed a statistically significant difference in the FRpeak parameter (F = 14.37, p < 0.001, η2p = 0.507) under the vibrotactile-enriched MBI condition compared to the baseline and active MBI conditions. In addition, significant beneficial effects were found on the results of the barognosis (F = 19.126, p < 0.001, η2p = 0. 577) and roughness differentiation subtests (F = 15.036, p < 0.001, η2p = 0.518) in the Manual Tactile Test for the participants in the vibrotactile-enriched MBI group. In addition, the participants under both the active MBI and vibrotactile-enriched MBI conditions exhibited better performance in the three subtests of the Purdue Pegboard Test as compared to under the baseline condition (p < 0.016).ConclusionsThe findings indicated that vibrotactile-enriched MBI potentially improves the precision pinch performance of hands in healthy older adults. In addition, the add-on effect of vibrotactile stimulation to the MBI condition provides beneficial effects on the sensory functions of the upper extremities.Trial registrationNCT04802564.Date of registration: 15/03/2021.The first posted date: 17/03/2021.

Are Mechanical Vibrations an Effective Alternative to Accelerate Orthodontic Tooth Movement in Humans? A Systematic Review

The objective of this article was to conduct a systematic review of the literature to contrast the existing evidence on the effect of mechanical vibrations, either high or low frequency, as an alternative to accelerate orthodontic tooth movement in humans. A literature search from 2010 to June 2021 was conducted in the electronic databases: PubMed, NCBI, Google Scholar, EBSCO, Cochrane, and Ovid, using the eligibility criteria to identify the studies. Only randomized clinical trials (RCT) were included. The certainty of the evidence was assessed using the GRADE tool and the risk of bias (RoB) in individual studies was evaluated according to the Cochrane bias risk tool. Fifteen RTCs were included for final review. Overall, the RoB was classified as low (3), moderate (5), and high (7). Three articles with low RoB, four with moderate RoB, and four with high RoB found no significant effect in the use of vibrations on orthodontic movement. Only four articles, three of them with high RoB and one with moderate RoB, found that mechanical vibrations are effective at accelerating orthodontic tooth movement. The results seemed to indicate that there is no evidence that vibratory stimuli can increase the rate of dental movement or reduce neither the time of dental alignment nor canine retraction during orthodontic treatment. It is important to note that a greater number of high-quality randomized controlled trials are urgently needed.

A novel Android app to evaluate and enhance auditory and tactile temporal thresholds.

With this work, we introduce a novel Android app designed to monitor and enhance auditory and tactile temporal sensitivity. To assess the app's reliability, we tested its technical performance evaluating stimuli production's accuracy (i.e., onset, offset, and duration of stimulation). To validate the app with participants we generated temporal intervals, using either sounds or vibratory stimuli, by implementing two versions of a Two-Alternative Forced-Choice (2AFC) task. Auditory and tactile temporal sensitivity of 12 participants was evaluated using this procedure. To investigate whether temporal abilities could be enhanced using the app, participants were then divided into two groups: one group was trained for four days on the auditory temporal task, while the other was trained for four days on the tactile temporal task. Results suggest that the app can i) effectively measure auditory and tactile temporal thresholds and ii) be used to enhance temporal abilities through perceptual learning. The accessibility of the experimental protocols, combined with our findings, fosters the app's involvement in rehabilitation programs, for example, with a specific focus on sensory disabilities that are associated with temporal deficits (e.g., deafness and Parkinson).Clinical Relevance- The current work introduces a novel app that can be used to monitor and improve temporal abilities, in both the auditory and the tactile modalities.

Intermittent vibratory stimulation to accelerate tooth movement: A clinical study

Vibratory stimulus is non-invasive and non-pharmacologic method for acceleration of Orthodontic tooth movement in adult patients. As powered toothbrush can provide cheaper alternative to Acceledent (a patent and expensive device) it was decided to evaluate the effectiveness of vibratory stimulation from powered toothbrush as a method of accelerating individual canine retraction.Sample consisted of 24 patients undergoing fixed Orthodontic treatment, in whom separate canine retraction was planned after extraction of all first premolars using NiTi closed coil spring. Force was standardized as 150 grams and checked at each appointment using Dontrix gauge. Following split mouth study design, right side was the experimental side where patients were asked to apply the vibratory stimulus through powered tooth brush (133Hz frequency) for 6 minutes (3 minutes labially and 3 minutes palatally) three times daily at regular intervals for a period of 3 months. Study models were taken at T0 (start of canine retraction), T1 (after 1st month), T2 (after 2nd month) and T3 (after 3rd month). Mean amount of canine movement and molar movement with respect to 3rd palatine rugae was measured on Digimizer software on both the sides for different time intervals.Statistically significant increase in canine movement was seen for total canine movement (T0-T3), movement from T0-T1 and from T2-T3. There was statistically insignificant difference in mesial movement of molars for different time intervals.There was an increased rate of canine movement on the side of vibratory stimulation (right side) in comparison to the control side (left side) for all time intervals and can be used to decrease treatment time in adults.

The Drosophila orthologue of the primary ciliary dyskinesia-associated gene, DNAAF3, is required for axonemal dynein assembly.

ABSTRACTCiliary motility is powered by a suite of highly conserved axoneme-specific dynein motor complexes. In humans, the impairment of these motors through mutation results in the disease primary ciliary dyskinesia (PCD). Studies in Drosophila have helped to validate several PCD genes whose products are required for cytoplasmic pre-assembly of axonemal dynein motors. Here we report the characterisation of the Drosophila orthologue of the less-known assembly factor DNAAF3. This gene, CG17669 (Dnaaf3), is expressed exclusively in developing mechanosensory chordotonal (Ch) neurons and the cells that generate spermatozoa, The only two Drosophila cell types bearing cilia/flagella containing dynein motors. Mutation of Dnaaf3 results in larvae that are deaf and adults that are uncoordinated, indicating defective Ch neuron function. The mutant Ch neuron cilia of the antenna specifically lack dynein arms, while Ca imaging in larvae reveals a complete loss of Ch neuron response to vibration stimulus, confirming that mechanotransduction relies on ciliary dynein motors. Mutant males are infertile with immotile sperm whose flagella lack dynein arms and show axoneme disruption. Analysis of proteomic changes suggest a reduction in heavy chains of all axonemal dynein forms, consistent with an impairment of dynein pre-assembly.

Vibration Sensitivity Is Associated With Functional Balance After Unilateral Transtibial Amputation

ObjectivesTo evaluate differences in vibration perception thresholds between adults with transtibial amputation and age-matched adults without amputation and to examine associations between vibration perception thresholds and balance performance. We hypothesized that adults with transtibial amputation would demonstrate lower thresholds compared with adults without amputation and that lower thresholds would be associated with better functional balance. DesignProspective cross-sectional study. SettingNational conference, clinical practice, and university laboratory. ParticipantsAdults (N=34) with a nondysvascular, unilateral, transtibial amputation and 43 age-matched controls without amputation. InterventionsParticipants’ vibration perception thresholds were evaluated bilaterally by applying a vibration stimulus to the midpatella and recording their verbal response to conscious perception of stimulus. Functional balance was assessed with the Berg Balance Scale and the Four Square Step Test. Main Outcome MeasuresResidual and sound limb (right and left for controls) vibration perception thresholds, Berg Balance Scale, and Four Square Step Test. ResultsFor participants with transtibial amputation and controls, there were no significant between-group (P=.921) or interlimb (P=.540) differences in vibration perception thresholds. Overall, robust regression models explained 35.1% and 19.3% variance in Berg Balance Scale scores and Four Square Step Test times, respectively. Among adults with transtibial amputation, vibration perception thresholds were negatively associated with Berg Balance Scale scores (P=.009) and positively associated with Four Square Step Test times (P=.048). Among controls, average vibration perception thresholds were not significantly associated with functional balance (P>.050). ConclusionsAdults with nondysvascular, transtibial-level amputation demonstrated similar vibration detection compared with adults with intact limbs, indicating that vibration detection is preserved in the amputated region postamputation. These findings suggest a unique relationship between vibration perception and functional balance post-transtibial amputation.

Efectos posturales inmediatos de la amplificación mecanoceptiva en niños con disfunciones neuromotrices, valorados mediante una plataforma de presiones Wii Balance Board. Estudio consecutivo no controlado

IntroductionNeurological disorders are a common cause of child disability. Neuromotor dysfunctions are currently being clinically faced through orthopedic, pharmacological and physiotherapeutic treatments. Therapeutic vibrations are studied to know their trophic and neuromodulator effects. ObjectiveTo observe the changes related to postural control in cases of infantile neuromotor dysfunction after the application of ecological vibratory stimuli, measured with a force platform. Patients and methodsConsecutive uncontrolled study. 15 subjects with motor disabilities and a mean age of 9±3.4 years were assessed in static standing using the Wii Balance Board platform before and after a single dose of mechanoceptive amplification (AM). Variables of the center of pressures were analyzed: mean position, mean excursion, amplitude and path length. ResultsThe pre-MA center of pressures mean position of the ensemble was further from the anatomical center on the frontal axis than on the sagittal axis in a statistically significant way (p=.041) and subjects showed significantly longer mediolateral path lengths of the center of pressures (p=.001) than the anteroposterior path lengths. Post-AM there were significant increases for the total mean excursion variable (p=.015), for the amplitude on the frontal axis (p=.010), and for the path length both in the total (p=.005) as in the partials of axes frontal (p=.006) and sagittal (p=.004). At the observational level, the mean sagittal position of the ensemble was posteriorized while the mean frontal position of the ensemble approached toward the center, with a high correlation between relocation/excursion and amplitude/path length. ConclusionThe subjects obtained a postural rebalancing tending toward posteriorization and toward the stimulated lower limb after MA.

A modality-specific somatosensory evoked potential test protocol for clinical evaluation: A feasibility study

ObjectiveWe aimed to establish an objective neurophysiological test protocol that can be used to assess the somatosensory nervous system. MethodsIn order to assess most fiber subtypes of the somatosensory nervous system, repetitive stimuli of seven different modalities (touch, vibration, pinprick, cold, contact heat, laser, and warmth) were synchronized with the electroencephalogram (EEG) and applied on the cheek and dorsum of the hand and dorsum of the foot in 21 healthy subjects and three polyneuropathy (PNP) patients. Latencies and amplitudes of the modalities were assessed and compared. Patients received quantitative sensory testing (QST) as reference. ResultsWe found reproducible evoked potentials recordings for touch, vibration, pinprick, contact-heat, and laser stimuli. The recording of warm-evoked potentials was challenging in young healthy subjects and not applicable in patients. Latencies were shortest within Aβ-fiber-mediated signals and longest within C-fibers. The test protocol detected function loss within the Aβ-fiber and Aδ-fiber-range in PNP patients. This function loss corresponded with QST findings. ConclusionIn this pilot study, we developed a neurophysiological test protocol that can specifically assess most of the somatosensory modalities. Despite technical challenges, initial patient data appear promising regarding a possible future clinical application. SignificanceEstablished and custom-made stimulators were combined to assess different fiber subtypes of the somatosensory nervous system using modality-specific evoked potentials.

Immediate effects of vibration biofeedback on ankle kinematics in people with chronic ankle instability

BackgroundPeople with chronic ankle instability are more inverted during initial contact and loading response which may increase the risk of subsequent ankle injuries. Vibration feedback gait retraining causes medial center of pressure shifts but its impact on ankle kinematics remains unknown. The purpose of this study was to understand kinematic ankle changes in people with chronic ankle instability following vibration feedback gait retraining. MethodsNineteen participants with chronic ankle instability walked with vibration feedback for 10 min on a treadmill and for one mile in the real-world. A vibration stimulus occurred at the lower leg when pressure under the 5th metatarsal exceeded a threshold. Three-dimensional kinematics of the ankle were recorded in the lab before and after training. Paired t-tests compared baseline and posttest ankle, hindfoot, and forefoot positions during initial contact and loading response for the lab and real-world conditions. FindingsAfter lab training the ankle (mean difference:-1.68 ± 1.62°, effect size:0.95) and forefoot (mean difference:-1.68 ± 1.67°, effect size:0.92) were more abducted. After real-world training, the ankle (mean difference:-1.19 ± 2.12°, effect size:0.54) and forefoot (mean difference:-1.87 ± 3.00°, effect size:0.63) were more everted. Similarly the ankle (mean difference:-2.37 ± 4.79°, effect size:0.46) and forefoot (mean difference:-2.78 ± 4.91°, effect size:0.51) were more abducted after real-world training. InterpretationVibration feedback decreases inversion and adduction during loading response. However, RW compared to lab training may have more beneficial frontal plane changes for people with chronic ankle instability.

Assessment of helicopter passengers’ vibration discomfort: proposal for improvement of the ISO 2631-1 standard

ABSTRACT High levels of vibration exist in helicopters and manufacturers are seeking to quantify vibration discomfort. They use the ISO 2631-1 standard, proposed for all types of transport. This study aimed to verify the validity of this index in the specific case of helicopters. Perception tests were carried out in the laboratory. Volunteers assessed the discomfort of vibratory stimuli on test benches generating vertical and triaxial vibrations. Foot, seat and backrest accelerations were measured for each participant according to each stimulus. The ISO 2631-1 comfort indices were then compared with the evaluations given by the participants. The results showed that the standard provided a good estimate of discomfort. However, it lacks precision in estimating the discomfort of stimuli which include amplitude modulations, as can happen in helicopters. A new discomfort index is proposed based on ISO 2631-1 and allows better prediction of subjective assessments. Practitioner summary: An improved index based on ISO 2631-1 standard is proposed to estimate helicopter vibratory discomfort for seated passengers. It takes into account the amplitude modulations that can appear at low frequencies in helicopters. This modification allowed a significant improvement of the accuracy of ISO 2631-1 for such stimuli.

A common computational principle for vibrotactile pitch perception in mouse and human

We live surrounded by vibrations generated by moving objects. These oscillatory stimuli propagate through solid substrates, are sensed by mechanoreceptors in our body and give rise to perceptual attributes such as vibrotactile pitch (i.e. the perception of how high or low a vibration’s frequency is). Here, we establish a mechanistic relationship between vibrotactile pitch perception and the physical properties of vibrations using behavioral tasks, in which vibratory stimuli were delivered to the human fingertip or the mouse forelimb. The resulting perceptual reports were analyzed with a model demonstrating that physically different combinations of vibration frequencies and amplitudes can produce equal pitch perception. We found that the perceptually indistinguishable but physically different stimuli follow a common computational principle in mouse and human. It dictates that vibrotactile pitch perception is shifted with increases in amplitude toward the frequency of highest vibrotactile sensitivity. These findings suggest the existence of a fundamental relationship between the seemingly unrelated concepts of spectral sensitivity and pitch perception.

Degree of muscle-and-tendon tonus effects on kinesthetic illusion in wrist joints toward advanced rehabilitation robotics

AbstractDue to increasing demand for rehabilitation and therapy for cerebrovascular diseases, patients require advanced development of medical rehabilitation robots. In our laboratory, we focus on the formation capability of the substitute neural path caused by brain plasticity using the kinesthetic illusion (KI), which is effective for therapies using robots. In KI, people perceive an illusionary limb movement without an actual movement when a vibration stimulus is applied to a limb’s tendons. In previous research, the optimal frequency that induces the maximum KI has a correlation factor of about 0.5 with the tendon’s natural frequency when a human subject is in a state of laxity. However, we do not know whether the above finding can be applied to actual rehabilitation because muscles and tendons are sometimes in tonus during rehabilitation, a state that varies the natural frequency. In this study, we investigate the correlation between the optimal and natural frequencies of tendon by systematically changing their tension to clarify the effects on the illusion induced by the muscle and the tendon when they are in tonus. We identified a negative correlation between the optimal and natural frequencies when they are in tonus, although a positive correlation appeared when they are in laxity. This result suggests that KI’s optimal frequency should be changed based on the degree of the tendon and muscle tonus. Therefore, our present findings provide a suitable vibration frequency that induces KI due to the degree of the tendon and muscle tonus during robot therapies.

Effects of vibratory feedback stimuli through an oral appliance on sleep bruxism: a 6-week intervention trial

Various biofeedback stimulation techniques of managing sleep bruxism (SB) have recently emerged; however, the effect of successive application of vibratory feedback stimulation has not been clarified. This study elucidated the effect of vibration feedback stimulation via an oral appliance (OA) on SB when vibration feedback was applied for 4weeks. This was a prospective, single-arm, open-label, intervention study. Ten participants diagnosed with "definite" SB wore a specially designed OA for 45 nights in a home-setting. A force-based SB detection system, including a pressure-sensitive piezoelectric film placed internally in the OA, triggered a vibrator attached to the OA. Vibratory stimulation was withheld during the first 2-week adaptation period (1st-15th nights), applied during the 4-week stimulation period (16th-43rd nights), and again withheld during the post-stimulation period (44th and 45th nights). The number and duration of SB episodes/hour of sleep were calculated based on masseter electromyographic activity recorded with in-home portable polysomnography and compared between the 15th and 45th nights (without stimulation) and the 17th and 43rd nights (with stimulation). The number and duration of SB episodes significantly decreased after vibratory stimulation (15th vs. 17th nights: p = 0.012 and p = 0.012, respectively), then significantly increased upon cessation of vibratory stimulation after the stimulation period (43rd vs. 45th nights: p = 0.023 and p = 0.023, respectively). Contingent vibratory stimulation through an OA may suppress SB-related masticatory muscle activity continuously for 4weeks and may be an effective alternative for the management of SB. https://jrct.niph.go.jp/ ; trial registration number: jRCTs032190225.

Embryo-to-embryo communication facilitates synchronous hatching in grasshoppers

Synchronous hatching within single egg clutches is moderately common in locusts and other insects and can be mediated by vibrational stimuli generated by adjacent embryos. However, in non-locust grasshoppers, there has been little research on the patterns of egg hatching and the mechanisms controlling the time of hatching. In this study, the hatching patterns of six grasshoppers (Atractomorpha lata, Oxya yezoensis, Acrida cinerea, Chorthippus biguttulus, Gastrimargus marmoratus, and Oedaleus infernalis) were observed under various laboratory treatments. Under continuous illumination and a 25/30°C thermocycle, the eggs of these grasshoppers tended to hatch during the first half of the daily warm period. Eggs removed from egg pods and cultured at 30°C tended to hatch significantly earlier and more synchronously when kept in groups vs. singly. In general, eggs hatched earlier when egg group size was increased. Egg hatching was stimulated by hatched nymphs in some species, but not in others. In all species, two eggs separated by several millimeters on sand hatched less synchronously than those kept in contact with one another, but the hatching synchrony of similarly separated eggs was restored if they were connected by a piece of wire, suggesting that a physical signal transmitted through the wire facilitated synchronized hatching. In contrast, hatching times in the Emma field cricket, Teleogryllus emma, which lays single, isolated eggs, were not influenced by artificial clumping in laboratory experiments. These results are discussed and compared with the characteristics of other insects.

A self-powered and high-frequency vibration sensor with layer-powder-layer structure for structural health monitoring

Vibration sensors greatly benefit medical and healthcare monitoring, environmental monitoring, and structural health monitoring. However, most of them are shadowed by relatively low-frequency vibration response, the narrow operating frequency range, and operational complexity, which hinders their use in wide practical applications. Here, we report a self-powered broadband vibration sensor with a layer-powder-layer structure based on a triboelectric nanogenerator. The internal polytetrafluoroethylene (PTFE) and silver (Ag) micro powder can vibrate under the external vibration stimuli, offering distinct advantages for high-frequency vibration sensing. The high-frequency triboelectric vibration sensor exhibits a significantly broad frequency response range of 3–133 kHz. The highest response frequency is approximately 1–3 orders of magnitude higher than most previously reported triboelectric vibration sensors. Additionally, the HVS shows directional independence, a good frequency resolution of 0.01 kHz, and small hysteresis. With these capabilities, the HVS was demonstrated in burst vibration detection, rail track fracture detection, automobile engine monitoring, and geological exploration applications. The facile and effective vibration monitoring system based on the HVS can provide a platform for various vibration monitoring applications. The self-powered high-frequency vibration sensor is a promising candidate for next-generation vibration sensors.

Torsional and translational vibrations of a eukaryotic nucleus, and the prospect of vibrational mechanotransduction and therapy

Certain eukaryotic cells are believed to sense and respond to vibrational stimuli that are too small even to be transduced by mechanosensitive ion channels. One possible mechanism of signal amplification and transduction is torsional and translational resonance of the nucleus, the stiffest and densest organelle in a eukaryotic cell. To explore this possibility, we developed a theoretical model that analyzes the natural frequencies of torsional and translational vibrations of the nucleus. The model predicts that the natural frequency for torsional vibration is dependent upon cytoskeletal contractility, while that for translational vibration is dependent upon cytoskeletal stiffness. Further analysis across many species and cell types suggests that, for most eukaryotic cells, torsional vibration is the dominant form of nuclear response to higher frequency stimuli, providing a new potential mechanism for frequency-based mechanotransduction.

Static and dynamic proprioceptive recognition through vibrotactile stimulation

Objective. Proprioceptive information provides individuals with a sense of our limb’s static position and dynamic movement. Impaired or a lack of such feedback can diminish our ability to perform dexterous motions with our biological limbs or assistive devices. Here we seek to determine whether both static and dynamic components of proprioception can be recognized using variation of the spatial and temporal components of vibrotactile feedback. Approach. An array of five vibrotactors was placed on the forearm of each subject. Each tactor was encoded to represent one of the five forearm postures. Vibratory stimulus was elicited to convey the static position and movement of the forearm. Four experimental blocks were performed to test each subject’s recognition of a forearm’s simulated static position, rotational amplitude, rotational amplitude and direction, and rotational speed. Main results. Our results showed that the subjects were able to perform proprioceptive recognition based on the delivered vibrotactile information. Specifically, rotational amplitude recognition resulted in the highest level of accuracy (99.0%), while the recognition accuracy of the static position and the rotational amplitude-direction was the lowest (91.7% and 90.8%, respectively). Nevertheless, all proprioceptive properties were perceived with >90% accuracy, indicating that the implemented vibrotactile encoding scheme could effectively provide proprioceptive information to the users. Significance. The outcomes suggest that information pertaining to static and dynamic aspects of proprioception can be accurately delivered using an array of vibrotactors. This feedback approach could be used to potentially evaluate the sensorimotor integration processes during human–machine interactions, and to improve sensory feedback in clinical populations with somatosensory impairments.

Perspectives of using vibrational communication data to develop safe methods for insect population size control

The transition to organic farming requires the development of new methods of population pest control without using insecticides. Accumulating evidence of insect vibrational communication indicate that the use of natural and modified signals pests may impede their successful communication on the plant, thereby reducing their population. Therefore, this study was conducted during 20 August to 16 October 2020 at Kharkevich Institute and discusses the effectiveness of using impetuses on the example widespread species Pentatoma rufipes which can damage large range of plants. Artificial models of stimuli, which were based on calling songs and rival signals of P. rufipes changed the behavior of female insects authentically in compared with control variant. The differences between duration of latent periods and number of successful approaches to the source of stimuli were discovered. There were shown, that artificial stimuli were attractive for females, wherein the difference of preferences between calling song and rival signals were more likely qualitative, i.e., stimuli were attractive equally. This fact explains by the way that agonistic behavior of males was directed only on the representatives of the same gender, not on females. We suppose that these signals can be used to increase efficiency of traditional methods of pest control, for example for attract insects to glue or pheromone traps. Both calling song (N = 16) and rival (N = 15) signals were used as stimuli. Two main behavioral responses of females to the stimulus were assessed - the latency period from the beginning of the stimulus application to the start of active movement of the female, % of successful approaches to the stimulus source. Control - no stimulus (N=15). The latency periods with and without stimulation differed significantly. The percentage of positive responses to stimuli was significantly higher than in the control (U-Mann-Whitney test; * p <0.05). On the contrary, the latency period before the onset of activity in the absence of a stimulus was significantly longer (Mann-Whitney U-test; p <0.05). No significant differences were found in the number of approaches to the stimulus between calling songs and rival signals. However, there is a noticeable tendency to an increase in the number of approaches when playing the calling song (62 and 48%, respectively). Differences in the latent periods of the activity of females in control and during stimulation show that the vibrational signals of males have a communication value. In future, the authors plan to show that when used together, vibration stimuli will increase the effectiveness of traditional glue and pheromone traps for P. rufipes.