Bio-Inspired Soft Artificial Muscles for Robotic and Healthcare Applications

Soft robotics and soft artificial muscles have emerged as prolific research areas and have gained substantial traction over the last two decades. There is a large paradigm shift of research interests in soft artificial muscles for robotic and medical applications due to their soft, flexible and compliant characteristics compared to rigid actuators. Soft artificial muscles provide safe human-machine interaction, thus promoting their implementation in medical fields such as wearable assistive devices, haptic devices, soft surgical instruments and cardiac compression devices. Depending on the structure and material composition, soft artificial muscles can be controlled with various excitation sources, including electricity, magnetic fields, temperature and pressure. Pressure-driven artificial muscles are among the most popular soft actuators due to their fast response, high exertion force and energy efficiency. Although significant progress has been made, challenges remain for a new type of artificial muscle that is easy to manufacture, flexible, multifunctional and has a high length-to-diameter ratio. Inspired by human muscles, this thesis proposes a soft, scalable, flexible, multifunctional, responsive, and high aspect ratio hydraulic filament artificial muscle (HFAM) for robotic and medical applications. The HFAM consists of a silicone tube inserted inside a coil spring, which expands longitudinally when receiving positive hydraulic pressure. This simple fabrication method enables low-cost and mass production of a wide range of product sizes and materials. This thesis investigates the characteristics of the proposed HFAM and two implementations, as a wearable soft robotic glove to aid in grasping objects, and as a smart surgical suture for perforation closure. Multiple HFAMs are also combined by twisting and braiding techniques to enhance their performance. In addition, smart textiles are created from HFAMs using traditional knitting and weaving techniques for shape-programmable structures, shape-morphing soft robots and smart compression devices for massage therapy. Finally, a proof-of-concept robotic cardiac compression device is developed by arranging HFAMs in a special configuration to assist in heart failure treatment. Overall this fundamental work contributes to the development of soft artificial muscle technologies and paves the way for future comprehensive studies to develop HFAMs for specific medical and robotic requirements

Evaluation of Administrative Service Quality Towards JKN Patient Satisfaction

Based on BPJS Kesehatan data, there was a decrease in Participant Satisfaction Index by 0.3% in 2016. The number of outpatient visits in RSUD KRT. Setjonegoro Wonosobo has decreased in 2016. Based on preliminary study, there were problems mainly related to health services provided by RSUD KRT. Setjonegoro Wonosobo. The purpose of this study was to determine how the quality of administrative services affect the satisfaction of JKN patients. This research used qualitative research methods. Data collection was conducted using observation and interview techniques. The results showed that the quality of administrative services in RSUD KRT. Setjonegoro seen from the dimensions of tangibles, reliability, responsiveness, assurance, and empathy is good. All the main informants were satisfied enough with the health services provided by the hospital. The advice given was to improve the performance in by conducting regular evaluation of the services provided

A temperature-dependent, variable-stiffness endoscopic robotic manipulator with active heating and cooling

In flexible endoscopy, the endoscope needs to be sufficiently flexible to go through the tortuous paths inside the human body and meanwhile be stiff enough to withstand external payloads without unwanted tip bending during operation. Thus, an endoscope whose stiffness can be adjusted on command is needed. This paper presents a novel variable-stiffness manipulator. The manipulator (Ø15 mm) has embedded thermoplastic tubes whose stiffness is tunable through temperature. Temperature is adjusted through joule heat generated by the electrical current supplied to the stainless steel coils and an active air-cooling mechanism. Tests and modeling were conducted to characterize the performance of the design. The manipulator has a high stiffness-changing ratio (22) between rigid and flexible states while that of its commercial Olympus counterpart is only 1.59. The active cooling time is 11.9 s while that of passive ambient cooling is 100.3 s. The thermal insulation layer (Aerogel) keeps the temperature of the outer surface within the safe range (below 41 °C). The models can describe the heating and cooling processes with root mean square errors ranging from 0.6 to 1.3 °C. The results confirm the feasibility of a variable-stiffness endoscopic manipulator with high stiffness-changing ratio, fast mode-switching, and safe thermal insulation.NRF (Natl Research Foundation, S’pore)Accepted versio

Distal-end force prediction of tendon-sheath mechanisms for flexible endoscopic surgical robots using deep learning

Accurate haptic feedback is highly challenging for flexible endoscopic surgical robots due to space limitation for sensors on small end-effectors and critical force hysteresis of their tendon-sheath mechanisms (TSMs). This paper proposes a deep learning approach to predicting the distal force of TSMs when manipulating a biological tissue based on only proximal-end measurements. Both Multilayer Perceptron (MLP) and Recurrent Neural Network (RNN) were investigated to study their capabilities of making sequential distal force predictions. The results were compared with those of the conventional modelling approach. It was observed that, when sufficient data was provided for training, RNN achieved the most accurate prediction (RMSE = 0.0219 N) in experiments with constant system velocity. The effects of insufficient training data, varying system velocity and irregular motion trajectories on the performance of RNN were further studied. Notably, RNN could precisely identify the current system phase in the force hysteresis profile and can be applied to TSMs with realistic non-periodic movement such as manual manipulation trajectory (RSME = 0.2287 N). The proposed approach can be applied to any TSM-driven robotic systems for accurate haptic feedback without requiring sensors at the distal ends of the robots.Accepted versio

Distal end force sensing with optical fiber Bragg gratings for tendon-sheath mechanisms in flexible endoscopic robots

Accurate haptic feedback is a critical challenge for surgical robots, especially for flexible endoscopic surgical robots whose transmission systems are Tendon-Sheath Mechanisms (TSMs) with highly nonlinear friction profiles and force hysteresis. For distal end haptic sensing of TSMs, this paper, for the first time, proposes to measure the compression force on the sheath at the distal end so that the tension force on the tendon, which equals the compression force on the sheath, can be obtained. A new force sensor, i.e., a nitinol tube attached with an optical Fiber Bragg Grating (FBG) fiber, is proposed to measure the compression force on the sheath. This sensor, with similar diameter and configuration (hollow) as the sheath, can be compactly integrated with TSMs and surgical end-effectors. In this paper, mechanics analysis and verification tests are presented to reveal the relationship between the tension force on the tendon and the compression force on the sheath. The proposed force sensor was calibrated in tests with a sensitivity of 24.28 pm/N and integrated with a tendon-sheath driven grasper to demonstrate the effectiveness of the proposed approach and sensor. The proposed approach and sensor can also be applied for a variety of TSMs-driven systems, such as robotic fingers/hands, wearable devices, and rehabilitation devices.NRF (Natl Research Foundation, S’pore)Accepted versio

A subject-specific four-degree-of-freedom foot interface to control a surgical robot

This paper introduces a passive four-degree-of-freedom foot interface to control a robotic surgical instrument. This interface is based on a parallel-serial hybrid mechanism with springs and force sensors. In contrast to existing switch-based interfaces that can command a slave robot arm at constant speeds in only discrete directions, the novel interface provides an operator with intuitive control in continuous directions and speeds with force and position feedback. The output command of the interface was initially derived based on the kinematics and statics of the interface. Since distinct movement patterns among different subjects were observed in a pilot test, a data-driven approach using Independent Component Analysis (ICA) was developed to convert the foot inputs to the control command of the user. The capability of this interface in controlling a robotic arm in multiple degrees of freedom was further verified with a teleoperation test.NRF (Natl Research Foundation, S’pore)Accepted versio

Joint rotation angle sensing of flexible endoscopic surgical robots

Accurate motion control of surgical robots is critical for the efficiency and safety of both state-of-the-art teleoperated robotic surgery and the ultimate autonomous robotic surgery. However, fine motion control for a flexible endoscopic surgical robot is highly challenging because of the shape-dependent and speed-dependent motion hysteresis of tendon-sheath mechanisms (TSMs) in the long, tortuous, and dynamically shape-changing robot body. Aiming to achieve precise closed-loop motion control, we propose a small and flexible sensor to directly sense the large and sharp rotations of the articulated joints of a flexible endoscopic surgical robot. The sensor - a Fiber Bragg Grating (FBG) eccentrically embedded in a thin and flexible epoxy substrate - can be significantly bent with a large bending angle range of [-62.9°, 75.5°] and small bending radius of 6.9 mm. Mounted in-between the two pivot-connected links of a joint, the sensor will bend once the joint is actuated, resulting in the wavelength shift of the FBG. In this study, the relationship between the wavelength shift and the rotation angle of the joint was theoretically modeled and then experimentally verified before and after the installation of the sensor in a robotic endoscopic grasper. The sensor, with the calibrated model, can track the rotation of the robotic joint with an RMSE of 3.34°. This small and flexible sensor has good repeatability, high sensitivity (around 147.5 pm/degree), and low hysteresis (7.72%). It is suitable for surgical robots and manipulators whose articulated joints have a large rotation angle and small bending radius.National Research Foundation (NRF)Accepted versionThis work was supported by National Research Foundation (NRF) Singapore (NRFI2016-07)