无缆式微机器人内窥镜系统的研制及离体实验

研制了一种用基于直流电机的直线驱动器实现机器人仿蚯蚓蠕动的无缆式微机器人内窥镜系统。该系统由无线通信控制模块、PC机、微机器人、无线能量传输控制器和无线能量发射线圈组成,用无线方式来实现人机通信和能量传输,解决了传统机器人内窥镜拖缆带来的肠壁损伤问题。研究工作包括微机器人的运动原理分析,无线能量传输简化模型的建立,无线能量传输原理的推导,以及系统离体实验的实施。实验表明:该微机器人的直线驱动器最大输出力为2.55N,机器人在能量传输范围内驱动电压稳定,满足系统运行要求。微机器人在离体猪结肠和小肠内运行均平稳、可靠。机器人摄像通信模块能够实时拍摄并传送出肠道内壁的图像。该研究为进一步实现人体全肠道无创诊疗奠定了基础。     

Imprinting on empty hard gelatin capsule shells containing titanium dioxide by application of the UV laser printing technique

The purpose of this study was to examine the application of ultraviolet (UV) laser irradiation to printing hard gelatin capsule shells containing titanium dioxide (TiO₂) and to clarify how the color strength of the printing by the laser could be controlled by the power of the irradiated laser. Hard gelatin capsule shells containing 3.5% TiO₂ were used in this study. The capsules were irradiated with pulsed UV laser at a wavelength of 355?nm. The color strength of the printed capsule was determined by a spectrophotometer as total color difference (dE). The capsules could be printed gray by the UV laser. The formation of many black particles which were agglomerates of oxygen-defected TiO₂ was associated with the printing. In the relationship between laser peak power of a pulse and dE, there were two inflection points. The lower point was the minimal laser peak power to form the black particles and was constant regardless of the dosage forms, for example film-coated tablets, soft gelatin capsules and hard gelatin capsules. The upper point was the minimal laser peak power to form micro-bubbles in the shells and was variable with the formulation. From the lower point to the upper point, the capsules were printed gray and the dE of the printing increased linearly with the laser peak power. Hard gelatin capsule shells containing TiO₂ could be printed gray using the UV laser printing technique. The color strength of the printing could be controlled by regulating the laser energy between the two inflection points.     

胶囊微机电无线能量传输系统设计与试验研究

首先介绍了胶囊微机电无线电能传输系统的原理和系统的基本构成,然后设计了以松耦合变压器为基础的无线电能供给系统,采用互相正交的二维线圈来接收能量并进行试验研究.结果表明:不管体内微机电系统处在何种位置和姿态,都可以有效接收能量,特别在初级绕组窗口宽度内,次级绕组接收能量可以高达110～240 mW.最后研制了胶囊微机电无...     

Process and formulation variables affecting the performance of a rupturable capsule-based drug delivery system with pulsatile drug release

The objective of this study was to optimize several process and formulation parameters, which influence the performance of a rupturable, pulsatile drug delivery system. The system consisted of a drug-containing hard gelatin capsule, a swelling layer of croscarmellose (Ac-Di-Sol®) and a binder, and an outer ethylcellulose coating. Polyvinyl pyrrolidone (Kollidon 90F) was superior to HPMC and HPC as a binder for the swelling layer with regard to binding (adherence to capsule) and disintegration properties of the swelling layer. The capsule-to-capsule uniformity in the amount of swelling layer and outer ethylcellulose coating, which significantly affected the lag time prior to rupture of the capsule, was optimized by decreasing the batch size, and by increasing the rotational pan speed and the distance between the spray nozzle and the product bed. The type of baffles used in the coating pan also affected the layering uniformity. Fully-filled hard gelatin capsules had a shorter lag time with a higher reproducibility compared to only half-filled capsules, because the swelling pressure was directed primarily to the outer ethylcellulose coating and not to the inner capsule core. Stability studies revealed that the lag time of the capsules was stable over a 240-day period when the moisture content was kept unchanged.     

Locomotion control of hybrid cockroach robots

Natural systems retain significant advantages over engineered systems in many aspects, including size and versatility. In this research, we develop a hybrid robotic system using American (Periplaneta americana) and discoid (Blaberus discoidalis) cockroaches that uses the natural locomotion and robustness of the insect. A tethered control system was firstly characterized using American cockroaches, wherein implanted electrodes were used to apply an electrical stimulus to the prothoracic ganglia. Using this approach, larger discoid cockroaches were engineered into a remotely controlled hybrid robotic system. Locomotion control was achieved through electrical stimulation of the prothoracic ganglia, via a remotely operated backpack system and implanted electrodes. The backpack consisted of a microcontroller with integrated transceiver protocol, and a rechargeable battery. The hybrid discoid roach was able to walk, and turn in response to an electrical stimulus to its nervous system with high repeatability of 60%.     

Optical Pliers: Micrometer-Scale,Light-Driven Tools Grown on Optical Fibers

The ability to grip and handle small objects, from sub-millimeter electronic components to single-micrometer living cells, is vital for numerous ever-shrinking technologies. Mechanical grippers, powered by electric, pneumatic, hydraulic or piezoelectric servos, are well suited for the job at larger scales, but their complexity and need for force transmission prevent their miniaturization and remote control in tight spaces. Using liquid crystal elastomer microstructures that can change shape quickly and reversibly in response to light, a light-powered gripping tool—optical pliers—is built by growing two bending jaws on the tips of optical fibers. By delivering UV light to trigger polymerization via a micrometer-size fiber core, structures of similar size can be made without resorting to any microfabrication technology, such as laser photolithography. The tool is operated using visible light energy supplied through the fibers, with no force transmission. The elastomer growth technique readily offers micrometer-scale, remotely controlled functional structures with different modes of actuation as building blocks for the microtoolbox.     

Optimized Identification with Severity Factors of Gastric Cancer for Internet of Medical Things

The Internet of Medical Things (IoMT) emerges with the vision of the Wireless Body Sensor Network (WBSN) to improve the health monitoring systems and has an enormous impact on the healthcare system for recognizing the levels of risk/severity factors (premature diagnosis, treatment, and supervision of chronic disease i.e., cancer) via wearable/electronic health sensor i.e., wireless endoscopic capsule. However, AI-assisted endoscopy plays a very significant role in the detection of gastric cancer. Convolutional Neural Network (CNN) has been widely used to diagnose gastric cancer based on various feature extraction models, consequently, limiting the identification and categorization performance in terms of cancerous stages and grades associated with each type of gastric cancer. This paper proposed an optimized AI-based approach to diagnose and assess the risk factor of gastric cancer based on its type, stage, and grade in the endoscopic images for smart healthcare applications. The proposed method is categorized into five phases such as image pre-processing, Four-Dimensional (4D) image conversion, image segmentation, K-Nearest Neighbour (K-NN) classification, and multi-grading and staging of image intensities. Moreover, the performance of the proposed method has experimented on two different datasets consisting of color and black and white endoscopic images. The simulation results verified that the proposed approach is capable of perceiving gastric cancer with 88.09% sensitivity, 95.77% specificity, and 96.55% overall accuracy respectively.     

Multifunctionalized polymer microcapsules: novel tools for biological and pharmacological applications

We describe recent developments with multifunctional nanoengineered polymer capsules. In addition to their obvious use as a delivery system, multifunctional nanocontainers find wide application in enzymatic catalysis, controlled release, and directed drug delivery in medicine. The multifunctionality is provided by the following components: 1) Luminescent semiconductor nanocrystals (quantum dots) that facilitate imaging and identification of different capsules, 2) superparamagnetic nanoparticles that allow manipulation of the capsules in a magnetic field, 3) surface coatings, which target the capsules to desired cells, 4) metallic nanoparticles in the capsule wall that act as an absorbing antenna for electromagnetic fields and provide heat for controlled release, and 5) enzymes and pharmaceutical agents that allow specific reactions. The unique advantage of multifunctional microcapsules in comparison to other systems is that they can be simultaneously loaded/functionalized with the above components, allowing for the combination of their properties in a single object.     

Redox-controlled molecular permeability of composite-wall microcapsules

Many smart materials in bioengineering, nanotechnology and medicine allow the storage and release of encapsulated drugs on demand at a specific location by an external stimulus. Owing to their versatility in material selection, polyelectrolyte multilayers are very promising systems in the development of microencapsulation technologies with permeation control governed by variations in the environmental conditions. Here, organometallic polyelectrolyte multilayer capsules, composed of polyanions and polycations of poly(ferrocenylsilane) (PFS), are introduced. Their preparation involved layer-by-layer self-assembly onto colloidal templates followed by core removal. PFS polyelectrolytes feature redox-active ferrocene units in the main chain. Incorporation of PFS into the capsule walls allowed us to explore the effects of a new stimulus, that is, changing the redox state, on capsule wall permeability. The permeability of these capsules could be sensitively tuned via chemical oxidation, resulting in a fast capsule expansion accompanied by a drastic permeability increase in response to a very small trigger. The substantial swelling could be suppressed by the application of an additional coating bearing common redox-inert species of poly(styrene sulfonate) (PSS(-)) and poly(allylamine hydrochloride) (PAH(+)) on the outer wall of the capsules. Hence, we obtained a unique capsule system with redox-controlled permeability and swellability with a high application potential in materials as well as in bioscience.     

Preparation of hydrogel capsules with thermoresponsive interpenetrating polymer network using concentric two-fluid nozzles

Hydrogel capsules in which shell was composed of thermoresponsive interpenetrating polymer network (IPN) of crosslinked poly(N-isopropylacrylamide) (PNIAPM) and calcium alginate, were prepared using concentric two-fluid nozzles. To introduce different amount of PNIPAM into the capsule shell, the concentrations of the NIPAM monomer and the polymerization initiator were changed in a wide range and the characteristics of the resulting capsules were evaluated. Spherical and uniformly sized capsules were obtained under all conditions. Elemental analyses showed that the PNIPAM/alginate weight ratio increased with the increase of initial concentrations of NIPAM monomer and polymerization initiator and was proportional to the initial rate of polymerization. In addition, the thermoresponsive properties of IPN hydrogel capsule were measured at temperatures from 10 °C to 50 °C and the thermoresponsive volume change ratio was expressed as a function of the PNIPAM/alginate weight ratio raised to a power. From these results, the relationship between the experimental conditions and the amount of PNIPAM in the capsule shell was clarified, and it indicated the magnitude of volume change of IPN hydrogel capsules can be controlled by introducing the desired amount of PNIPAM in the capsules.     

基于Faster R-CNN改进的数粒机系统

目的解决目前数粒机只能计数不能同时分拣残损药粒的问题。方法设计以Faster R-CNN深度神经网络为核心的药粒数粒机系统。在原有的数粒机基础之上,更换CCD线阵相机为面阵相机,以满足图像采集的需求,进一步使用图像分割和多线程技术加快图像处理速度。最终通过训练好的Faster R-CNN网络检测出目标并分拣。结果经过测试集的验证,正常药粒识别率达到了95.47%,残损药粒识别率达到了97.94%,单幅图像处理达到了65 ms的实时速度。结论该方法在传统的计数基础上很好地融合了先进的深度学习技术,实现了目标的自动分拣。     

Nanometer-sized molybdenum-iron oxide capsule-surface modifications: external and internal

The cluster {(Mo)Mo5}12Fe(III)30 1 a present in compound 1 (cluster diameter approximately 2.3 nm), which belongs to the family of nanoscale spherical porous {(Mo)Mo5}12{Linker}30 capsules that allow a new type of nanochemistry inside their cavities as well as unprecedented aggregation processes under gaseous, solution, and solid-state conditions, is the starting material for the present investigation. In solution it reacts with LnCl3 x nH2O (Ln = Ce, Pr) thereby replacing six Fe(III) ions with Ln(III) ions to form compounds 2 (Ce) and 3 (Pr). During metal-cation exchange, some of the pentagonal {(Mo)Mo5O21(H2O)6}6- units, which are connected to the Fe(III) centers in 1 a, decompose, thus leading to a temporary capsule opening and uptake of the formed smaller molybdate units into the capsule cavities. In 2 and 3, the pentagonal units are connected via 24 Fe(III) and six Ln(III)-type linkers/spacers representing together the capsule skeletons, which are structurally well-defined in contrast to the capsule contents. The new capsules self-associate into single-layer blackberry-type structures, thus extending the variety of these types of assemblies; the assembly process, that is, the size of the final species, can be controlled by the pH, which allows the generation of differently sized nanoparticles. Magnetic properties of the two new nanomaterials 2 and 3 are also determined.     

Nanoengineered polymer capsules: tools for detection, controlled delivery, and site-specific manipulation

We present the concept of multifunctional nanoengineered polymer capsules and outline their applications as new drug delivery systems or supramolecular toolboxes containing, for example, enzymes capable of converting nontoxic prodrugs into toxic drugs at a designated location. Such functionalized nanocontainers offer a wide range of applications including enzymatic catalysis, controlled release, and directed drug delivery in medicine due to their multifunctionality. The unique advantage of capsules in comparison to other systems is that they can be functionalized or loaded simultaneously with the above-mentioned components, thus permitting multifunctional processes in single cells.     

Hard gelatin and hypromellose (HPMC) capsules: estimation of rupture time by real-time dissolution spectroscopy

The objective of this study was to measure rupture time of gelatin and hypromellose (hydroxypropyl methylcellulose or HPMC) capsules using a novel approach based on real-time dissolution spectroscopy. Rupture time was measured in standard dissolution apparatus at a constant temperature using a dip-type fiber-optic probe. Labrasol released from the capsules was treated as the marker of the rupture process. Light scatter generated by the emulsified labrasol was detected by an ultrafast monochromator at scan rates approximating 24,000 nm/min. This technique was validated by measuring the dissolution time of gelatin capsules. Rupture times of hypromellose capsules were studied as a function of capsule size, capsule grade, and dissolution medium. Statistical correlations were analyzed by ANOVA. Rupture time of hypromellose capsules was dependent on both the medium and the grade of the capsule, and was independent of capsule size. The composition of the dissolution medium contributes to the rupture time of the capsules and should be considered when fast release and quick biological response is desired. Release delay, however, may not manifest itself in vivo and the time to maximum plasma concentration may not be significant.     

Remotely Light‐Powered Soft Fluidic Actuators Based on Plasmonic‐Driven Phase Transitions in Elastic Constraint

Materials capable of actuation through remote stimuli are crucial for untethering soft robotic systems from hardware for powering and control. Fluidic actuation is one of the most applied and versatile actuation strategies in soft robotics. Here, the first macroscale soft fluidic actuator is derived that operates remotely powered and controlled by light through a plasmonically induced phase transition in an elastomeric constraint. A multiphase assembly of a liquid layer of concentrated gold nanoparticles in a silicone or styrene–ethylene–butylene–styrene elastic pocket forms the actuator. Upon laser excitation, the nanoparticles convert light of specific wavelength into heat and initiate a liquid‐to‐gas phase transition. The related pressure increase inflates the elastomers in response to laser wavelength, intensity, direction, and on–off pulses. During laser‐off periods, heating halts and condensation of the gas phase renders the actuation reversible. The versatile multiphase materials actuate—like soft “steam engines”—a variety of soft robotic structures (soft valve, pnue‐net structure, crawling robot, pump) and are capable of operating in different environments (air, water, biological tissue) in a single configuration. Tailored toward the near‐infrared window of biological tissue, the structures actuate also through animal tissue for potential medical soft robotic applications.     

A comparison of the puncturing properties of gelatin and hypromellose capsules for use in dry powder inhalers

This study investigates capsule puncture in dry powder inhalers. Gelatin and hydroxypropylmethyl cellulose (HPMC) capsules (stored at 11 and 33% relative humidities) were punctured using a pin from a Foradil inhaler, with insertion force measurement via an Instron tester. In HPMC capsules, the force after capsule puncture reduced by half and then increased to a second maximum as the pin shaft entered the hole. In gelatin capsules, the postpuncture force reduced to zero, indicating shell flaps losing contact with the pin. At lower moisture contents, both capsules were less flexible. This provides a tool to measure the shell properties of inhalation capsules.     

A Comparison of the Puncturing Properties of Gelatin and Hypromellose Capsules for Use in Dry Powder Inhalers

This study investigates capsule puncture in dry powder inhalers. Gelatin and hydroxypropylmethyl cellulose (HPMC) capsules (stored at 11 and 33% relative humidities) were punctured using a pin from a Foradil® inhaler, with insertion force measurement via an Instron tester. In HPMC capsules, the force after capsule puncture reduced by half and then increased to a second maximum as the pin shaft entered the hole. In gelatin capsules, the postpuncture force reduced to zero, indicating shell flaps losing contact with the pin. At lower moisture contents, both capsules were less flexible. This provides a tool to measure the shell properties of inhalation capsules.     

“Smart” Surface Capsules for Delivery Devices

This review describes emerging trends, basic principles, applications, and future challenges for designing next generation responsive “smart” surface capsules. Advances and importance of “surface” capsules which are not deposited onto the surface but are built into the surface are highlighted for selective applications with specific examples of surface sponge structures formed by high intensity ultrasonic surface treatment (HIUS). Surface capsules can be adapted for biomedical applications, membrane materials, lab‐on‐chip, organ‐on‐chip, and for template synthesis. They provide attractive self‐healing anticorrosion and antifouling prospects. Nowadays delivery systems are built from inorganic, organic, hybrid, biological materials to deliver various drugs from low molecular weight substances to large protein molecules and even live cells. It is important that capsules are designed to have time prolonged release features. Available stimuli to control capsule opening are physical, chemical and biological ones. Understanding the underlying mechanisms of capsule opening by different stimuli is essential for developing new methods of encapsulation, release, and targeting. Development of “smart” surface capsules is preferable to respond to multiple stimuli. More and more often a new generation of “smart” capsules is designed by a bio‐inspired approach.     

Untethered Recyclable Tubular Actuators with Versatile Locomotion for Soft Continuum Robots

Stimuli‐responsive materials offer a distinguished platform to build tether‐free compact soft robots, which can combine sensing and actuation without a linked power supply. In the past, tubular soft robots have to be made by multiple components with various internal channels or complex cavities assembled together. Moreover, robust processing, complex locomotion, simple structure, and easy recyclability represent major challenges in this area. Here, it is shown that those challenges can be tackled by liquid crystalline elastomers with allyl sulfide functional groups. The light‐controlled exchange reaction between allyl sulfide groups allows flexible processing of tubular soft robots/actuators, which does not need any assisting materials. Complex locomotion demonstrated here includes reversible simultaneous bending and elongation; reversible diameter expansion; and omnidirectional bending via remote infrared light control. Different modes of actuation can be programmed into the same tube without the routine assembly of multiple tubes as used in the past. In addition, the exchange reaction also makes it possible to use the same single tube repeatedly to perform different functions by erasing and reprogramming.     

Hard Gelatin and Hypromellose (HPMC) Capsules: Estimation of Rupture Time by Real-time Dissolution Spectroscopy

ABSTRACT

The objective of this study was to measure rupture time of gelatin and hypromellose (hydroxypropyl methylcellulose or HPMC) capsules using a novel approach based on real-time dissolution spectroscopy. Rupture time was measured in standard dissolution apparatus at a constant temperature using a dip-type fiber-optic probe. Labrasol released from the capsules was treated as the marker of the rupture process. Light scatter generated by the emulsified labrasol was detected by an ultrafast monochromator at scan rates approximating 24,000 nm/min. This technique was validated by measuring the dissolution time of gelatin capsules. Rupture times of hypromellose capsules were studied as a function of capsule size, capsule grade, and dissolution medium. Statistical correlations were analyzed by ANOVA. Rupture time of hypromellose capsules was dependent on both the medium and the grade of the capsule, and was independent of capsule size. The composition of the dissolution medium contributes to the rupture time of the capsules and should be considered when fast release and quick biological response is desired. Release delay, however, may not manifest itself in vivo and the time to maximum plasma concentration may not be significant.