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1.
Sensors (Basel) ; 23(10)2023 May 21.
Article in English | MEDLINE | ID: mdl-37430855

ABSTRACT

In this study, we introduce a novel design for a three-dimensional (3D) controller, which incorporates the omni-purpose stretchable strain sensor (OPSS sensor). This sensor exhibits both remarkable sensitivity, with a gauge factor of approximately 30, and an extensive working range, accommodating strain up to 150%, thereby enabling accurate 3D motion sensing. The 3D controller is structured such that its triaxial motion can be discerned independently along the X, Y, and Z axes by quantifying the deformation of the controller through multiple OPSS sensors affixed to its surface. To ensure precise and real-time 3D motion sensing, a machine learning-based data analysis technique was implemented for the effective interpretation of the multiple sensor signals. The outcomes reveal that the resistance-based sensors successfully and accurately track the 3D controller's motion. We believe that this innovative design holds the potential to augment the performance of 3D motion sensing devices across a diverse range of applications, encompassing gaming, virtual reality, and robotics.

2.
Polymers (Basel) ; 13(24)2021 Dec 17.
Article in English | MEDLINE | ID: mdl-34960983

ABSTRACT

Precise motion control is important in robotic surgery, especially corneal surgery. This paper develops a new tension-measurement system for forceps used in corneal surgery, wherein contact force is applied only to a specific location for precise control, with precise movements detected by attaching a nano-crack sensor to the corresponding part. The nano-crack sensor used here customizes the working range and sensor sensitivity to match the strain rate of the tip of the forceps. Therefore, the tension in the suture can be sufficiently measured even at suture failure. The printed circuit board attached to the bottom of the system is designed to simultaneously collect data from several sensors, visualizing the direction and magnitude of the tension in order to inform the surgeon of how much tension is being applied. This system was verified by performing pig-corneal suturing.

3.
ACS Nano ; 15(10): 15815-15823, 2021 Oct 26.
Article in English | MEDLINE | ID: mdl-34546714

ABSTRACT

Many industries have a significant but largely unmet need for efficient and high-flux emulsion separation, particularly for nanoemulsions. Conventional separation membranes rely on size-based separation mainly utilizing a sieving mechanism plus a wetting phenomenon, resulting in a dramatic trade-off between separation efficiency and separation flux. Herein we address this challenge by adapting electrokinetics to membrane-based separation, using a charge-based mechanism capable of separating even nanoemulsions with a demonstrated separation efficiency of >99% and ultrahigh flux up to 40 000 L/H·m2. Our device arrests nano-oil droplets, allowing them to coalesce into larger droplets which are then able to be filtered by coarser membranes. This hybrid technology makes electrokinetic-assisted filtration scalable and commercially viable and allows for a better understanding of the multiphysics underlying dynamic separation.

4.
Polymers (Basel) ; 13(7)2021 Mar 26.
Article in English | MEDLINE | ID: mdl-33810563

ABSTRACT

Oblique submicron-scale structures are used in various aspects of research, such as the directional characteristics of dry adhesives and wettability. Although deposition, etching, and lithography techniques are applied to fabricate oblique submicron-scale structures, these approaches have the problem of the controllability or throughput of the structures. Here, we propose a simple X-ray-lithography method, which can control the oblique angle of submicron-scale structures with areas on the centimeter scale. An X-ray mask was fabricated by gold film deposition on slanted structures. Using this mask, oblique ZEP520A photoresist structures with slopes of 20° and 10° and widths of 510 nm and 345 nm were fabricated by oblique X-ray exposure, and the possibility of polydimethylsiloxane (PDMS) molding was also confirmed. In addition, through double exposure with submicron- and micron-scale X-ray masks, dotted-line patterns were produced as an example of multiscale patterning.

5.
Lab Chip ; 19(18): 2958-2965, 2019 09 10.
Article in English | MEDLINE | ID: mdl-31393468

ABSTRACT

Recently, nanochannels have been widely adopted in microfluidic systems, especially for biosensing and bio-concentrators. Here, we report an on-demand micro/nano-convertible channel, which consists of a simple configuration of elastic nanostructure underneath a single microchannel. By the degree of pressure applied by a pushrod, the microchannel starts to compress into a size-tunable micro- or nano-porous channel. In this approach, under an electric field, we have successfully derived the electrokinetic characteristics of three different regimes: (1) microchannel regime, (2) microporous regime, and (3) nanochannel regime. Utilizing the practical advantage of the transition between regimes with its low cost and easy integration, we demonstrate the pre-concentration and label-free sensing of DNA using a single on-demand convertible channel. Moreover, we demonstrate an ionic diode by applying asymmetric pressure on the elastic nanostructure to create an asymmetric geometry. We believe that the on-demand convertible channel holds potential for promising applications in bioanalytical and iontronic fields.


Subject(s)
Microfluidic Analytical Techniques , Nanostructures/chemistry , Nanotechnology , Elasticity , Microfluidic Analytical Techniques/instrumentation , Nanotechnology/instrumentation , Particle Size , Surface Properties
6.
Medicine (Baltimore) ; 97(27): e11369, 2018 Jul.
Article in English | MEDLINE | ID: mdl-29979423

ABSTRACT

Despite the importance of strengthening of the transversus abdominis (TrA) muscle in individuals with low back pain, the effect of real-time ultrasound imaging on maintenance in selective strengthening of abdominal hallowing exercise (AHE) performance has not been investigated. So, the aim of this study was to investigate the effects of AHE with real-time ultrasound imaging feedback on selective reinforcing the TrA muscle.Twenty healthy subjects were enrolled prospectively and randomized to train AHE for 2 weeks either by conventional feedback (group A) or by visual feedback from real-time ultrasound imaging additional to conventional feedback (group B). The changes in thickness of TrA, internal oblique abdominal muscle (IO), and external oblique abdominal muscle (EO) were measured using the ultrasonography. The changes in muscle activities of TrA-IO and EO were measured using surface electromyography.The thickness of TrA, IO, and EO muscles in resting was not significantly changed in both groups A and B. However, the ratio of root mean square (RMS) values of TrA-IO/EO muscles, which mirrors selective contraction of TRA-IO muscles against EO muscle, was significantly higher in group B than in group A.In healthy subjects, training with AHE using real-time ultrasound imaging feedback may be a useful additional method to conventional feedback for strengthening the TrA muscles selectively.


Subject(s)
Abdominal Muscles/physiology , Biofeedback, Psychology/methods , Exercise Therapy/methods , Abdominal Muscles/diagnostic imaging , Adult , Electromyography/methods , Healthy Volunteers , Humans , Muscle Contraction/physiology , Prospective Studies , Ultrasonography/methods
7.
Sensors (Basel) ; 18(4)2018 Apr 12.
Article in English | MEDLINE | ID: mdl-29649102

ABSTRACT

This paper details the design of a poly(dimethylsiloxane) (PDMS)-shielded waterproof crack-based stretchable strain sensor, in which the electrical characteristics and sensing performance are not influenced by changes in humidity. This results in a higher number of potential applications for the sensor. A previously developed omni-purpose stretchable strain (OPSS) sensor was used as the basis for this work, which utilizes a metal cracking structure and provides a wide sensing range and high sensitivity. Changes in the conductivity of the OPSS sensor, based on humidity conditions, were investigated along with the potential possibility of using the design as a humidity sensor. However, to prevent conductivity variation, which can decrease the reliability and sensing ability of the OPSS sensor, PDMS was utilized as a shielding layer over the OPSS sensor. The PDMS-shielded OPSS sensor showed approximately the same electrical characteristics as previous designs, including in a high humidity environment, while maintaining its strain sensing capabilities. The developed sensor shows promise for use under high humidity conditions and in underwater applications. Therefore, considering its unique features and reliable sensing performance, the developed PDMS-shielded waterproof OPSS sensor has potential utility in a wide range of applications, such as motion monitoring, medical robotics and wearable healthcare devices.

8.
Nanoscale ; 10(6): 3037-3045, 2018 Feb 08.
Article in English | MEDLINE | ID: mdl-29376157

ABSTRACT

Oil spills and an increasing demand for the treatment of industrial oily wastewater are driving the need for continuous large-scale oil/water separation processes. Herein, we report a nanofibrous cellulosic membrane (NFC membrane) for the continuous high-flux separation of large amounts of oil/water mixtures. The NFC membrane was fabricated using wet electrospinning, a facile yet effective method for stacking nanofibrous membranes with uniform porous structures on a substrate. Owing to its cellulosic nature, the membrane showed excellent underwater superoleophobicity along with robust chemical stability and was able to separate oil/water mixtures at efficiencies exceeding 99%. Repetitive oil/water separations could be performed using a single membrane, during which the oil content in the filtrate remained extremely low (<29 ppm). The nanofibrous membrane exhibited a fine porous structure that was interconnected throughout the membrane, resulting in a high oil intrusion pressure (>30 kPa) that allowed not only gravity-driven but also pressure-driven separation of oil/water mixtures. The separation flux reached 120 000 L m-2 h-1 during pressure-driven separations, which is a very promising feature for actual applications such as the large-scale treatment of industrial oily wastewater.

9.
ACS Appl Mater Interfaces ; 9(48): 41712-41721, 2017 Dec 06.
Article in English | MEDLINE | ID: mdl-29130301

ABSTRACT

Here, we report an omni-purpose stretchable strain sensor (OPSS sensor) based on a nanocracking structure for monitoring whole-body motions including both joint-level and skin-level motions. By controlling and optimizing the nanocracking structure, inspired by the spider sensory system, the OPSS sensor is endowed with both high sensitivity (gauge factor ≈ 30) and a wide working range (strain up to 150%) under great linearity (R2 = 0.9814) and fast response time (<30 ms). Furthermore, the fabrication process of the OPSS sensor has advantages of being extremely simple, patternable, integrated circuit-compatible, and reliable in terms of reproducibility. Using the OPSS sensor, we detected various human body motions including both moving of joints and subtle deforming of skin such as pulsation. As specific medical applications of the sensor, we also successfully developed a glove-type hand motion detector and a real-time Morse code communication system for patients with general paralysis. Therefore, considering the outstanding sensing performances, great advantages of the fabrication process, and successful results from a variety of practical applications, we believe that the OPSS sensor is a highly suitable strain sensor for whole-body motion monitoring and has potential for a wide range of applications, such as medical robotics and wearable healthcare devices.


Subject(s)
Motion , Human Body , Humans , Reproducibility of Results
10.
Am J Phys Med Rehabil ; 96(8): e155-e158, 2017 Aug.
Article in English | MEDLINE | ID: mdl-28081026

ABSTRACT

Posterior drooling, which can lead to substantial respiratory morbidity, including unexplained lung diseases and recurrent pneumonia, is an important issue in the rehabilitation unit. There are various treatment options for posterior drooling, including pharmacologic therapy, oral motor or behavioral therapy, biofeedback, local glandular injection of botulinum toxin, irradiation, and surgery. Among them, nebulized glycopyrrolate has the following advantages: It is noninvasive and is relatively free of central adverse effects because it does not cross the blood-brain barrier unlike other anticholinergics. Although there has been one case report regarding the effectiveness of nebulized glycopyrrolate for drooling in a motor neuron patient, there have not been any reports on its effectiveness for posterior drooling. Herein, we report two cases (an 82-year-old male bilateral hemiplegic stroke patient and a 1-year-old female cerebral palsy infant with bilaterally spastic hemiplegia of posterior drooling treated with nebulized glycopyrrolate) and identify salivary aspiration and the effect of nebulized glycopyrrolate using radionuclide salivagram. Considering its advantages and effectiveness, nebulized glycopyrrolate should be considered as one of the reliable methods to manage posterior drooling in patients with impaired cognition or swallowing difficulties, such as severe brain injury.


Subject(s)
Cerebral Palsy/complications , Glycopyrrolate/administration & dosage , Muscarinic Antagonists/administration & dosage , Sialorrhea/drug therapy , Stroke/complications , Administration, Inhalation , Aged, 80 and over , Female , Hemiplegia/complications , Humans , Infant , Male , Nebulizers and Vaporizers , Salivary Glands/drug effects , Sialorrhea/etiology , Treatment Outcome
11.
Sensors (Basel) ; 16(7)2016 Jul 19.
Article in English | MEDLINE | ID: mdl-27447639

ABSTRACT

Recently, much research has been focused on stretchable or flexible electronic sensors for the measurement of strain or deformation on movable and variably shaped objects. In this research, to evaluate the performance of stretchable strain sensors, we have designed an integrated evaluation system capable of simultaneously measuring the change in stress and conductance of a strain sensor. Using the designed system, we have successfully evaluated the deformation characteristics, sensing range and sensing sensitivity of a stretchable strain sensor. We believe that the developed integrated evaluation system could be a useful tool for performance evaluation of stretchable strain sensors.

12.
Ann Rehabil Med ; 40(1): 28-33, 2016 Feb.
Article in English | MEDLINE | ID: mdl-26949666

ABSTRACT

OBJECTIVE: To evaluate the clinical usefulness of sonoelastography in infants with congenital muscular torticollis (CMT). METHODS: The medical records of 215 infants clinically diagnosed with CMT were retrospectively reviewed. Fifty-three infants met the inclusion criteria as follows: 1) infants diagnosed as CMT with a palpable neck mass before 3 months of age, 2) infants who were evaluated initially by both B-mode ultrasonography and sonoelastography, and 3) infants who had received physical therapy after being diagnosed with CMT. We checked the thickness of the sternocleidomastoid (SCM) muscles in B-mode ultrasonography, strain ratio of the SCM muscles in sonoelastography, and treatment duration. We evaluated the correlation between the treatment duration and the following factors: SCM muscle thickness, ratio of SCM muscle thickness on the affected to unaffected side (A/U ratio), and strain ratio. RESULTS: Both the thickness of the affected SCM muscle and the A/U ratio did not show significant correlation with the treatment duration (p=0.66, p=0.90). The strain ratio of the affected SCM muscle was significantly greater than that of the unaffected SCM muscle (p<0.001), and the strain ratio showed significant correlation with the treatment duration (p=0.001). CONCLUSION: Sonoelastography may be a useful adjunctive tool to B-mode ultrasonography for evaluating infants with CMT, especially when predicting their rehabilitation outcomes.

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