Ultrasound Feedback Research Articles

Effects of Production Training With Ultrasound Biofeedback on Production and Perception of Second-Language English Tense-Lax Vowel Contrasts.

This study investigated the efficacy of ultrasound biofeedback compared to a traditional acoustic input-only method in the second-language (L2) production training of English tense-lax vowel contrasts (/i-ɪ/ and /e-ɛ/). The relationship between the degrees of production and perception learning was also examined to explore a potential L2 production-perception link. Using a pretest/training/posttest paradigm, two groups of native Mandarin speakers received three sessions of training, one with ultrasound and one with audio only. Perception performance was measured by accuracy in AX discrimination. Production performance was measured in terms of accuracy in repetition production and Euclidean distance between contrasting vowels. Both groups showed significant improvements in posttest production and perception tasks. Additionally, the training benefits were retained 6 weeks after training. The two groups, however, did not differ significantly in training gains; nor was there a significant correlation between training-induced changes in perception and production performance. The results indicate that ultrasound feedback is similarly effective as the audio-only training in improving the L2 production of English tense-lax contrasts and the benefits transferred to perception. The lack of correlation between production and perception gains suggests that the two modalities need to be separately trained to achieve desired L2 learning outcomes.

Closed‐Loop Control Characterization of Untethered Small‐Scale Helical Device in Physiological Fluid with Dynamic Flow Rates

Untethered small‐scale helical devices (USHDs) have the potential to navigate blood vessels and treat vascular occlusive diseases. However, there are still many challenges in translating this method into clinical practice, both in terms of localization and wireless motion control. Herein, closed‐loop control characterization of the USHD against and along physiological fluid inside a blood vessel phantom at different penetration depths is shown. First the dynamic flow and ultrasound images noise affecting the measurement are modeled, and control system of the USHD based on bifurcation analysis of a 1D hydrodynamic model is designed. Then a region of attraction of a USHD driven by a permanent magnet robotic (PMR) system inside a blood vessel phantom around an equilibrium point is constructed. Further, the point‐to‐point closed‐loop control strategy is implemented based on the magnetic point‐dipole approximation and kinematic control of the PMR system and ultrasound feedback inside physiological fluid, blood vessel, and soft tissue. The frequency response of the USHD is characterized against and along the flowing streams of fetal bovine serum within different flow rates in the 6–20 mm s−1range. The experimental results demonstrate the ability to navigate the USHD inside blood vessel phantoms with maximum position error of mm.

Steering Rotating Magnetic Swimmers in 2.5 Dimensions Using Only 2D Ultrasonography for Position Sensing

Micro/millimeter-scale magnetic robots have many potential biomedical applications. However, there are major challenges in using these devices for <i>in vivo</i> tasks due to limitations of imaging technology for real-time detection and navigation inside the human body. Ultrasound is a popular sensor for localizing such robots because it is easy to use and less expensive than other imaging methods. This letter studies methods to track and control a millimeter-scale rotating magnetic swimmer to perform path following. Detection using ultrasound B-mode and Doppler mode to track the robot during navigation are compared. In addition, an algorithm to perform 2.5D closed-loop control (controlling 3 degrees of freedom for a swimmer to follow a planar path) of the swimmer using only 2D ultrasound feedback was studied and tested experimentally.

Phase Optimization for Multipoint Haptic Feedback Based on Ultrasound Array.

Ultrasound-based haptic feedback is a potential technology for human–computer interaction (HCI) with the advantages of a low cost, low power consumption and a controlled force. In this paper, phase optimization for multipoint haptic feedback based on an ultrasound array was investigated, and the corresponding experimental verification is provided. A mathematical model of acoustic pressure was established for the ultrasound array, and then a phase-optimization model for an ultrasound transducer was constructed. We propose a pseudo-inverse (PINV) algorithm to accurately determine the phase contribution of each transducer in the ultrasound array. By controlling the phase difference of the ultrasound array, the multipoint focusing forces were formed, leading to various shapes such as geometries and letters, which can be visualized. Because the unconstrained PINV solution results in unequal amplitudes for each transducer, a weighted amplitude iterative optimization was deployed to further optimize the phase solution, by which the uniform amplitude distributions of each transducer were obtained. For the purpose of experimental verification, a platform of ultrasound haptic feedback consisting of a Field Programmable Gate Array (FPGA), an electrical circuit and an ultrasound transducer array was prototyped. The haptic performances of a single point, multiple points and dynamic trajectory were verified by controlling the ultrasound force exerted on the liquid surface. The experimental results demonstrate that the proposed phase-optimization model and theoretical results are effective and feasible, and the acoustic pressure distribution is consistent with the simulation results.

Real-Time Magnetic Navigation of a Rotating Colloidal Microswarm Under Ultrasound Guidance.

Untethered microrobots hold great promise for applications in biomedical field including targeted delivery, biosensing, and microsurgery. A major challenge of using microrobots to perform in vivo tasks is the real-time localization and motion control using medical imaging technologies. Here we report real-time magnetic navigation of a paramagnetic nanoparticle-based microswarm under ultrasound guidance. A three-axis Helmholtz electromagnetic coil system integrated with an ultrasound imaging system is developed for generation, actuation, and closed-loop control of the microswarm. The magnetite nanoparticle-based microswarm is generated and navigated using rotating magnetic fields. In order to localize the microswarm in real time, the dynamic imaging contrast has been analyzed and exploited in image process to increase the signal-to-noise ratio. Moreover, imaging of the microswarm at different depths are experimentally studied and analyzed, and the minimal dose of nanoparticles for localizing a microswarm at different depths is ex vivo investigated. For real-time navigating the microswarm in a confined environment, a PI control scheme is designed. Image differencing-based processing increases the signal-to-noise ratio, and the microswarm can be ex vivo localized at depth of 2.2-7.8cm. Experimental results show that the microswarm is able to be real-time navigated along a planned path in a channel, and the average steady-state error is 0.27mm ( ∼33.7% of the body length). The colloidal microswarm is real-time localized and navigated using ultrasound feedback, which shows great potential for biomedical applications that require real-time noninvasive tracking.

IRONSperm: Sperm-templated soft magnetic microrobots.

We develop biohybrid magnetic microrobots by electrostatic self-assembly of nonmotile sperm cells and magnetic nanoparticles. Incorporating a biological entity into microrobots entails many functional advantages beyond shape templating, such as the facile uptake of chemotherapeutic agents to achieve targeted drug delivery. We present a single-step electrostatic self-assembly technique to fabricate IRONSperms, soft magnetic microswimmers that emulate the motion of motile sperm cells. Our experiments and theoretical predictions show that the swimming speed of IRONSperms exceeds 0.2 body length/s (6.8 ± 4.1 µm/s) at an actuation frequency of 8 Hz and precision angle of 45°. We demonstrate that the nanoparticle coating increases the acoustic impedance of the sperm cells and enables localization of clusters of IRONSperm using ultrasound feedback. We also confirm the biocompatibility and drug loading ability of these microrobots, and their promise as biocompatible, controllable, and detectable biohybrid tools for in vivo targeted therapy.

Rehabilitation of speech disorders following glossectomy, based on ultrasound visual illustration and feedback

ABSTRACT Intraoral surgery for tongue cancer usually induces speech disorders that have a negative impact on communication and quality of life. Studies have documented the benefit of tongue ultrasound imaging as a visual articulatory feedback for speech rehabilitation. This study aims to assess specifically the complementary contribution of visual feedback to visual illustration (i.e. the display of ultrasound video of target language movements) for the speech rehabilitation of glossectomised patients. Two therapy conditions were used alternately for ten glossectomised French patients randomly divided into two cohorts. The IF cohort benefitted from 10 sessions using illustration alone (IL condition) followed by 10 sessions using illustration supplemented by visual feedback (IL+F condition). The FI cohort followed the opposite protocol, i.e. the first 10 sessions with the IL+F condition, followed by 10 sessions with the IL condition. Phonetic accuracy (Percent Consonants Correct) was monitored at baseline (T0, before the first series) and after each series (T1 and T2) using clinical speech-language assessments. None of the contrasts computed between the two conditions, using logistic regression with random effects models, were found to be statistically significant for the group analysis of assessment scores. Results were significant for a few individuals, with balanced advantages in both conditions. In conclusion, the use of articulatory visual feedback does not seem to bring a decisive advantage over the use of visual illustration, though speech therapists and patients reported that ultrasound feedback was useful at the beginning. This result should be confirmed by similar studies involving other types of speech disorders.

Adaptation to a physical alteration of the vocal apparatus: The effect of visual self-perception on speech motor plasticity

Adapting speech movements to novel or perturbed conditions relies critically on the processing of self-produced sensory information. In the context of a physical alteration of the vocal apparatus (e.g., palatal prosthesis), talkers have been shown to adapt following 10–15 min of practice to produce improved acoustic output. It is possible that additional information, such as ultrasound imaging of the tongue, may help talkers adapt even more effectively to such perturbations. Providing visual feedback of the tongue surface in real-time has shown promise in the treatment of speech-sound disorders. However, it remains unclear whether the addition of such visual information will influence speech plasticity on the timescale examined in experimental studies of speech adaptation. Here, we examine how neurotypical talkers adapt to a palatal prosthesis, relying on auditory and somatosensory feedback alone (n = 15), or with the addition of ultrasound feedback of the tongue, either in the mid-sagittal (n = 15) or coronal plane (n = 15). Differences in adaptation performance between the three feedback conditions were observed, both in the patterns of speech adaptation and the learning after-effects. The results indicate that talkers will rapidly integrate visual articulatory information into their control of oral speech movements in order to guide productions towards improved acoustic outcomes.Adapting speech movements to novel or perturbed conditions relies critically on the processing of self-produced sensory information. In the context of a physical alteration of the vocal apparatus (e.g., palatal prosthesis), talkers have been shown to adapt following 10–15 min of practice to produce improved acoustic output. It is possible that additional information, such as ultrasound imaging of the tongue, may help talkers adapt even more effectively to such perturbations. Providing visual feedback of the tongue surface in real-time has shown promise in the treatment of speech-sound disorders. However, it remains unclear whether the addition of such visual information will influence speech plasticity on the timescale examined in experimental studies of speech adaptation. Here, we examine how neurotypical talkers adapt to a palatal prosthesis, relying on auditory and somatosensory feedback alone (n = 15), or with the addition of ultrasound feedback of the tongue, either in the mid-sagittal (n = 15) or co...

Tunability of Acoustic and Mechanical Behaviors in Breast Tissue Mimicking Materials.

In radiology practices, the ultrasound-guided breast biopsy is among the most commonly performed minimally invasive procedures. However, many radiology residents in their graduate residencies are found with little or no hands-on experience with ultrasound-guided breast procedures. To enhance safety, the problem can be solved by the use of anthropomorphic training phantoms which can provide the resident with realistic ultrasound imaging and needle insertion haptic feedback. Stiffness and acoustic properties of breast tissues vary between different people. The training breast phantom should be able to possess different acoustic and mechanical properties which conform the inconsistencies found in real tissues among people. Therefore, this paper investigates the tunability of acoustic and mechanical behaviors in breast tissue mimicking materials (TMMs). Experiments of central composite design (CCD) with a center point, four corner points, and an additional four axis points were used to fit the non-linear regression model of the speed of sound. The same design of experiment approach was then used to fit the second-order response surface of the attenuation coefficient. Suitable series of tissue mimicking materials for the glandular tissue and malignant lesion were suggested. Latin hypercube design method was conducted to evaluate the main factors that affected the mechanical property (Young's modulus) of tissue mimicking materials. The results showed that the recipe of tissue mimicking materials could be customized to possess different acoustic and mechanical properties which conform the inconsistencies found in real breast tissues.

Magnetic localization and control of helical robots for clearing superficial blood clots.

This work presents an approach for the localization and control of helical robots during removal of superficial blood clots inside in vitro and ex vivo models. The position of the helical robot is estimated using an array of Hall-effect sensors and precalculated magnetic field map of two synchronized rotating dipole fields. The estimated position is used to implement closed-loop motion control of the helical robot using the rotating dipole fields. We validate the localization accuracy by visual feedback and feature tracking inside the in vitro model. The experimental results show that the magnetic localization of a helical robot with diameter of 1 mm can achieve a mean absolute position error of 2.35 ± 0.4 mm (n = 20). The simultaneous localization and motion control of the helical robot enables propulsion toward a blood clot and clearing at an average removal rate of 0.67 ± 0.47 mm3/min. This method is used to localize the helical robot inside a rabbit aorta (ex vivo model), and the localization accuracy is validated using ultrasound feedback with a mean absolute position error of 2.6 mm.

The effectiveness of real-time ultrasound visual feedback on tongue movements in L2 pronunciation training

AbstractThe purpose of this study was to test the usability of ultrasound as a visual feedback tool in L2 pronunciation training. Six Japanese-speaking learners, aged 28–33 years, participating in a course in French phonetics for L2 learners, took part in the study. Four of them received three individual 45-minute lessons of ultrasound pronunciation training. The other two participants did not. Articulatory and acoustic data of French isolated /y/ and /u/ and Japanese [ɯ] were recorded before and after the ultrasound training, as well as two months later for the learners receiving the training. The analysis of the articulatory data revealed that three speakers with ultrasound feedback improved in the production of the French vowels, the contrast between them, as well as the contrast between the two French vowels and the Japanese [ɯ], suggesting that ultrasound may be a useful tool in second language pronunciation learning.

Mechanism of contrast-enhancement in ultrasound-modulated laser feedback imaging with ultrasonicmicrobubble contrast agent

Ultrasound-modulated optical imaging technology is a new type of biological tissue optical detection technology, and sensitive to the change of scattering coefficient and absorption coefficient of biological tissue. This technology is a non-ionizing and non-invasive pathological detection method, which has great potential application in early detection of cancer. However, ultrasound-modulated optical imaging technology is insufficient in signal-to-noise ratio (SNR) and imaging contrast. Frequency-shifted laser feedback technology with microchip laser is a new type of highly sensitive interference technology, whose gain coefficient for weak optical signal can reach 10&lt;sup&gt;6&lt;/sup&gt;. This technology can greatly improve the SNR of imaging. Combined with the high sensitive laser feedback technology, the ultrasound-modulated laser feedback technology is proposed. The SNR of this technology is better than that of the traditional ultrasound-modulated optical imaging technology. The increase in SNR can achieve greater depth of detection in biological tissue imaging, but there is no significant improvement in imaging contrast. In order to improve the contrast of biological tissue imaging and achieve high resolution imaging of thick biological tissue, we use ultrasound microbubble contrast agent in ultrasound-modulated laser feedback imaging technology. We establish a Monte Carlo photon transport model with microbubbles in order to study the mechanism of contrast enhancement in ultrasound-modulated laser feedback imaging with microbubbles. Finally, we establish an experimental system to verify the correctness of the simulation results. Experimental and simulation results show that in the transparent solution, the ultrasonic microbubble contrast agent can enhance the ultrasound-modulated laser feedback signal and generate harmonic modulation, which can improve the imaging contrast by detecting the enhancement of the fundamental and harmonic signals of the feedback. In the scattering medium, the ultrasonic microbubble contrast agent can significantly attenuate the ultrasound modulated laser feedback signal, and the imaging contrast can be improved by detecting the attenuation of the fundamental and harmonic signal.

Automatic Robotic Steering of Flexible Needles from 3D Ultrasound Images in Phantoms and Ex Vivo Biological Tissue.

Robotic control of needle bending aims at increasing the precision of percutaneous procedures. Ultrasound feedback is preferable for its clinical ease of use, cost and compactness but raises needle detection issues. In this paper, we propose a complete system dedicated to robotized guidance of a flexible needle under 3D ultrasound imaging. This system includes a medical robot dedicated to transperineal needle positioning and insertion, a rapid path planning for needle steering using bevel-tip needle natural curvature in tissue, and an ultrasound-based automatic needle detection algorithm. Since ultrasound-based automatic needle steering is often made difficult by the needle localization in biological tissue, we quantify the benefit of using flexible echogenic needles for robotized guidance under 3D ultrasound. The "echogenic" term refers to the etching of microstructures on the needle shaft. We prove that these structures improve needle visibility and detection robustness in ultrasound images. We finally present promising results when reaching targets using needle steering. The experiments were conducted with various needles in different media (synthetic phantoms and ex vivo biological tissue). For instance, with nitinol needles the mean accuracy is 1.2mm (respectively 3.8mm) in phantoms (resp. biological tissue).

Mechanical Rubbing of Blood Clots Using Helical Robots Under Ultrasound Guidance

A simple way to mitigate the potential negative side-effects associated with chemical lysis of a blood clot is to tear its fibrin network via mechanical rubbing using a helical robot. Here, we achieve mechanical rubbing of blood clots under ultrasound guidance and using external magnetic actuation. Position of the helical robot is determined using ultrasound feedback and used to control its motion toward the clot, whereas the volume of the clots is estimated simultaneously using visual feedback. We characterize the shear modulus and ultimate shear strength of the blood clots to predict their removal rate during rubbing. Our in vitro experiments show the ability to move the helical robot controllably toward clots using ultrasound feedback with average and maximum errors of ${\text{0.84}\pm \text{0.41}}$ and 2.15 mm, respectively, and achieve removal rate of $-\text{0.614} \pm \text{0.303}$ mm $^{3}$ /min at room temperature ( ${\text{25}}^{\circ }$ C) and $-\text{0.482} \pm \text{0.23}$ mm $^{3}$ /min at body temperature (37 $^{\circ}$ C), under the influence of two rotating dipole fields at frequency of 35 Hz. We also validate the effectiveness of mechanical rubbing by measuring the number of red blood cells and platelets past the clot. Our measurements show that rubbing achieves cell count of $(\text{46} \pm \text{10.9}) \times \text{10}^{4}$ cell/ml, whereas the count in the absence of rubbing is $(\text{2} \pm \text{1.41}) \times \text{10}^{4}$ cell/ml, after 40 min.

Magnetic Motion Control and Planning of Untethered Soft Grippers using Ultrasound Image Feedback.

Soft miniaturized untethered grippers can be used to manipulate and transport biological material in unstructured and tortuous environments. Previous studies on control of soft miniaturized grippers employed cameras and optical images as a feedback modality. However, the use of cameras might be unsuitable for localizing miniaturized agents that navigate within the human body. In this paper, we demonstrate the wireless magnetic motion control and planning of soft untethered grippers using feedback extracted from B-mode ultrasound images. Results show that our system employing ultrasound images can be used to control the miniaturized grippers with an average tracking error of 0.4±0.13 mm without payload and 0.36±0.05 mm when the agent performs a transportation task with a payload. The proposed ultrasound feedback magnetic control system demonstrates the ability to control miniaturized grippers in situations where visual feedback cannot be provided via cameras.

Ultrasound Images of the Tongue: A Tutorial for Assessment and Remediation of Speech Sound Errors.

Diagnostic ultrasound imaging has been a common tool in medical practice for several decades. It provides a safe and effective method for imaging structures internal to the body. There has been a recent increase in the use of ultrasound technology to visualize the shape and movements of the tongue during speech, both in typical speakers and in clinical populations. Ultrasound imaging of speech has greatly expanded our understanding of how sounds articulated with the tongue (lingual sounds) are produced. Such information can be particularly valuable for speech-language pathologists. Among other advantages, ultrasound images can be used during speech therapy to provide (1) illustrative models of typical (i.e."correct") tongue configurations for speech sounds, and (2) a source of insight into the articulatory nature of deviant productions. The images can also be used as an additional source of feedback for clinical populations learning to distinguish their better productions from their incorrect productions, en route to establishing more effective articulatory habits. Ultrasound feedback is increasingly used by scientists and clinicians as both the expertise of the users increases and as the expense of the equipment declines. In this tutorial, procedures are presented for collecting ultrasound images of the tongue in a clinical context. We illustrate these procedures in an extended example featuring one common error sound, American English /r/. Images of correct and distorted /r/ are used to demonstrate (1) how to interpret ultrasound images, (2) how to assess tongue shape during production of speech sounds, (3), how to categorize tongue shape errors, and (4), how to provide visual feedback to elicit a more appropriate and functional tongue shape. We present a sample protocol for using real-time ultrasound images of the tongue for visual feedback to remediate speech sound errors. Additionally, example data are shown to illustrate outcomes with the procedure.

Proactive Selective Inhibition Targeted at the Neck Muscles: This Proximal Constraint Facilitates Learning and Regulates Global Control.

While individual muscle function is known, the sensory and motor value of muscles within the whole-body sensorimotor network is complicated. Specifically, the relationship between neck muscle action and distal muscle synergies is unknown. This work demonstrates a causal relationship between regulation of the neck muscles and global motor control. Studying violinists performing unskilled and skilled manual tasks, we provided ultrasound feedback of the neck muscles with instruction to minimize neck muscle change during task performance and observed the indirect effect on whole-body movement. Analysis of ultrasound, kinematic, electromyographic and electrodermal recordings showed that proactive inhibition targeted at neck muscles had an indirect global effect reducing the cost of movement, reducing complex involuntary, task-irrelevant movement patterns and improving balance. This effect was distinct from the effect of gaze alignment which increased physiological cost and reduced laboratory-referenced movement. Neck muscle inhibition imposes a proximal constraint on the global motor plan, forcing a change in highly automated sensorimotor control. The proximal location ensures global influence. The criterion, inhibition of unnecessary action, ensures reduced cost while facilitating task-relevant variation. This mechanism regulates global motor function and facilitates reinforcement learning to change engrained, maladapted sensorimotor control associated with chronic pain, injury and performance limitation.

Limited acquisition and generalisation of rhotics with ultrasound visual feedback in childhood apraxia

ABSTRACTUltrasound visual feedback of the tongue is one treatment option for individuals with persisting speech sound errors. This study evaluated children’s performance during acquisition and generalisation of American English rhotics using ultrasound feedback. Three children aged 10–13 with persisting speech sound errors associated with childhood apraxia of speech (CAS) were treated for 14 one-hour sessions. Two of the participants increased the accuracy of their rhotic production during practise trials within treatment sessions, but none demonstrated generalisation to untreated words. Lack of generalisation may be due to a failure to acquire the target with sufficient accuracy during treatment, or to co-existing linguistic weaknesses that are not addressed in a motor-based treatment. Results suggest a need to refine the intervention procedures for CAS and/or a need to identify appropriate candidates for intervention to optimise learning.

TU-AB-201-12: Effects of Tissue Interference On Electromagnetic Sensor and Ultrasound Imaging Sensing for Robot-Guided Needle Interventions

Purpose: To quantify the effects of tissue interference on electromagnetic (EM) sensing and ultrasound (US) imaging feedback modalities for controlling a robot-guided medical needle interventions. Methods: First, the experimental set up to control the robot-guided needle insertion with and without tissue interference involving 6-DOF EM (Aurora, NDI, Waterloo, Canada) sensory feedback is constructed. Next, the experimental set up has been modified to replace EM sensory feedback with the bi-planer US imaging (Flex Focus 800, BK Medical, Peabody, MA) feedback. In both these experimental feedback cases the control task is to guide the needle intervention (vertically downwards to avoid the gravitational pull on the needle) as per the desired trajectory. For EM sensory feedback the thickness of the tissue used for interference is 90mm whereas for the US imaging feedback, the thickness is reduced to 25 mm as the needle was not visible from 90mm to 26 mm. Performance repeatability is assessed in five observations for each experiment. Results: The mean and standard deviation (SD) of the root mean square error (RMSE) value for the tracking performance using EM sensory feedback with no tissue interference are 0.10mm and 0.01mm, respectively. With tissue interference, these values are 0.14mm and 0.01mm. Corresponding mean RSME and SD with and without tissue interference using the US imaging modality are 0.15 mm (SD=0.02mm) and 0.41mm (SD=0.04mm), respectively. Conclusion: Experimental results reveal that there exists significant difference (p=0.0001) between the tracking performances with and without tissue interference using US imaging feedback. Whereas for the EM sensory feedback, there exists no significant difference (p=0.0576) between with and without tissue interference RMSE values. However, both the sensing modalities may be suitable for needle-based clinical applications. More rigorous study involving both EM and US feedback modalities in various soft tissue phantoms are in progress. Acknowledgement: Research supported by DoD (Grant#W81XWH-11-1-0397/98/99)

Rewarding Research

Rewarding Research