A Novel Tele-Operated Flexible Robot Targeted for Minimally Invasive Robotic Surgery

In this paper, a novel flexible robot system with a constrained tendon-driven serpentine manipulator(CTSM) is presented. The CTSM gives the robot a larger workspace, more dexterous manipulation, and controllable stiffness compared with the da Vinci surgical robot and traditional flexible robots. The robot is tele-operated using the Novint Falcon haptic device. Two control modes are implemented, direct mapping and incremental mode. In each mode, the robot can be manipulated using either the highest stiffness scheme or the minimal movement scheme. The advantages of the CTSM are shown by simulation and experimental results.

Simultaneously improving the EMI shielding performances and mechanical properties of CF/PEKK composites via MXene interfacial modification

In this study, two-dimensional MXene (Ti3 C2 Tx ) was employed to modify the interface of carbon fiber-reinforced polyetherketoneketone (CF/PEKK) composites, in order to simultaneously improve the electromagnetic interference (EMI) shielding performances and mechanical properties. The obtained CF/PEKK composites possessed outstanding EMI and mechanical performances, as anticipated. Specifically, the CF/PEKK composites modified with MXene at 1 mg mL–1 exhibited an excellent EMI shielding effectiveness of 65.2 dB in the X-band, a 103.1% enhancement compared with the unmodified CF/PEKK composites. The attractive EMI shielding performances of CF/PEKK composites originated from enhanced ohmic losses and multiple reflections of electromagnetic waves with the help of the MXene and CF layers. In addition, CF/PEKK composites achieved the best mechanical properties by optimizing the dispersion concentration of MXene to 0.1 mg mL–1 . The flexural strength, flexural modulus, and interlaminar shear strength of CF/PEKK composites reached 1127 MPa, 81 GPa, and 89 MPa, which were 28.5%, 9.5%, and 29.7% higher than that of the unmodified CF/PEKK composites, respectively. Such improvement in mechanical properties could be ascribed to the comprehensive effect of mechanical interlocking, hydrogen bonds, and Van der Waals forces between the introduced MXene and CF, PEKK, respectively.

Design and evaluation of a novel biopsy needle with hemostatic function

Biopsy is a method commonly used for early cancer diagnosis.However,bleeding complications of widely available biopsy are risky for patients.Safer biopsy will result in a more accurate cancer diagnosis and a decrease in the risk of complications.In this article,we propose a novel biopsy needle that can reduce bleeding during biopsy procedures and achieve stable hemostasis.The proposed biopsy needle features a compact structure and can be operated easily by left and right hands.A predictive model for puncture force and tip deflection based on coupled Eulerian–Lagrangian(CEL)method is developed.Experimental results show that the biopsy needle can smoothly deliver the gelatin sponge hemostatic plug into the tissue.Although the hemostatic plug bends,the overall delivery process is stable,and the hemostatic plug retains in the tissue without being affected by the withdrawal of the needle.Further experiments indicate that the specimens are well obtained and evenly distributed in the groove of the outer needle without scattering.Our proposed design of biopsy needle possesses strong ability of hemostasis,tissue cutting,and tissue retention.The CEL model accurately predicts the peak of puncture force and produces close estimation of the insertion force at the postpuncture stage and tip position.

Three-Dimensional Collision Avoidance Method for Robot-Assisted Minimally Invasive Surgery

In the robot-assisted minimally invasive surgery,if a collision occurs,the robot system program could be damaged,and normal tissues could be injured.To avoid collisions during surgery,a 3-dimensional collision avoidance method is proposed in this paper.The proposed method is predicated on the design of 3 strategic vectors:the collision-with-instrument-avoidance(CI)vector,the collision-with-tissues-avoidance(CT)vector,and the constrained-control(CC)vector.The CI vector demarcates 3 specific directions to forestall collision among the surgical instruments.The CT vector,on the other hand,comprises 2 components tailored to prevent inadvertent contact between the robot-controlled instrument and nontarget tissues.Meanwhile,the CC vector is introduced to guide the endpoint of the robot-controlled instrument toward the desired position,ensuring precision in its movements,in alignment with the surgical goals.Simulation results verify the proposed collision avoidance method for robot-assisted minimally invasive surgery.The code and data are available at https://github.com/cynerelee/collision-avoidance.

A Survey of Transoral Robotic Mechanisms:Distal Dexterity,Variable Stiffness,and Triangulation

Robot-assisted technologies are being investigated to overcome the limitations of the current solutions for transoral surgeries,which suffer from constrained insertion ports,lengthy and indirect passageways,and narrow anatomical structures.This paper reviews distal dexterity mechanisms,variable stiffness mechanisms,and triangulation mechanisms,which are closely related to the specific technical challenges of transoral robotic surgery(TORS).According to the structure features in moving and orienting end effectors,the distal dexterity designs can be classified into 4 categories:serial mechanism,continuum mechanism,parallel mechanism,and hybrid mechanism.To ensure adequate adaptability,conformability,and safety,surgical robots must have high flexibility,which can be achieved by varying the stiffness.Variable stiffness(VS)mechanisms based on their working principles in TORS include phase-transitionbased VS mechanism,jamming-based VS mechanism,and structure-based VS mechanism.Triangulations aim to obtain enough workspace and create adequate traction and counter traction for various operations,including visualization,retraction,dissection,and suturing,with independently controllable manipulators.The merits and demerits of these designs are discussed to provide a reference for developing new surgical robotic systems(SRSs)capable of overcoming the limitations of existing systems and addressing challenges imposed by TORS procedures.

A Review of Printable Flexible and Stretchable Tactile Sensors

Flexible and stretchable tactile sensors that are printable,nonplanar,and dynamically morphing are emerging to enable proprioceptive interactions with the unstructured surrounding environment.Owing to its varied range of applications in the field of wearable electronics,soft robotics,human-machine interaction,and biomedical devices,it is required of these sensors to be flexible and stretchable conforming to the arbitrary surfaces of their stiff counterparts.The challenges in maintaining the fundamental features of these sensors,such as flexibility,sensitivity,repeatability,linearity,and durability,are tackled by the progress in the fabrication techniques and customization of the material properties.This review is aimed at summarizing the recent progress of rapid prototyping of sensors,printable material preparation,required printing properties,flexible and stretchable mechanisms,and promising applications and highlights challenges and opportunities in this research paradigm.

Auto-generating of 2D tessellated crease patterns of 3D biomimetic spring origami structure

Computational simulations can accelerate the design and modelling of origami robots and mechanisms.This paper presents a computational method using algorithms developed in Python to generate different tessellated origami crease patterns simultaneously.This paper aims to automate this process by introducing a system that automatically generates origami crease patterns in Scalable Vector Graphics format.By introducing different parameters,variations of the same underlying tessellated crease pattern can be obtained.The user interface consists of an input file where the user can input the desired parameters,which are then processed by an algorithm written in Python to generate the respective origami 2D crease patterns.These origami crease patterns can serve as inputs to current origami design software and algorithms to generate origami design models for faster and easier visual comparison.This paper utilizes a basic biomimetic inspiration origami pattern to demonstrate the functionality by varying underlying crease pattern parameters that give rise to symmetric and asymmetric spring origami 3D structures.Furthermore,this paper conducts a qualitative analysis of the origami design outputs of an origami simulator from the input crease patterns and the respective manual folding of the origami structure.

A review of bio-inspired needle for percutaneous interventions

Bio-inspired design translates the knowledge of natural or biological structures or behaviors into novel theories and technologies,providing new directions for research and developments.Although the medical needles for percutaneous intervention technology appear to be mature,biomimetic solutions become popular to further facilitate the performance of the medical needles.In this paper,we review the current state of bio-inspired medical needle designs for percutaneous interventions,including a variety of biomimetic mechanisms and insertion strategies.Existing and experimental designs of biomimetic medical needles are classified into five groups with respect to the applications,while their characteristics are identified and discussed.Such classification and discussion will not only provide technical insights into previous studies but also identify undiscovered directions for future research.

Printable Kirigami-inspired Flexible and Soft Anthropomorphic Robotic Hand

We present a kirigami-inspired design scheme for a robotic hand by 3D printable folds and cuts.The unique contribution is the printable flexible hand,which provides flexibility and maneuverability that is unavailable in rigid robotic systems.The integration of sensors in the robotic system enables force adjustment for robotic systems applicable in the future.The experimental results have shown that this design can perform everyday tasks through grasping and pinching different items.The fingers can bend from 40 to 100 degrees.Furthermore,the direct printable kirigami cuts and folds from soft elastic printable materials have significant potential for prosthetic devices.The printable kirigami design framework opens the possibility for future developments and modifications in numerous robotic applications.

Real time in-vivo miniature endoscopic surveillance system for imaging of nasopharynx

Objective:To test the feasibility of a real time miniature endoscope system for imaging the nasopharynx.Study design:Preclinical assessment on skull model and cadaver.Methods:A 3.5 mm miniature endoscope was fabricated and the image capture of the nasopharynx was investigated by positioning the miniature camera system at the posterior free edge of the vomer bone.Wireless real time transmission of the images and quality was tested in a skull model.Next,three nasopharyngeal surveillance miniature camera system were developed for possible clinical translation.Two prototypes were anchored on the nasal septum and the last prototype was designed using a patient self-administered surveillance process.These prototypes were tested for feasibility on both the phantom skull and cadaveric model.Risk assessments were also performed to assess risk,safety and validate the reliability of the material utilized for clinical translation.Results:Insertion and anchorage of the miniature surveillance endoscope prototypes at the vomer bone were feasible on all 3 prototypes.The quality of captured images was reasonable and miniaturized camera was responsive to pan at different angles so that the entire nasopharynx may be surveyed.Risk assessments on the material such as pull out test,breaking force analysis,finite element test and tensile strength test were reliable for possible clinical translation.Conclusions:Real time miniature endoscope system for surveillance of nasopharyngeal cancer is feasible.Clinical translation of this technology was possible but requires further refinement in enhancing image quality and wireless transmission of the captured images.