Abstract Recent advances in minimally invasive surgery (MIS) have utilized a variety of equipment... more Abstract Recent advances in minimally invasive surgery (MIS) have utilized a variety of equipment, usually in the form of robotics, to aid surgeons during surgical procedures. This involves the manipulation and navigation of long tools and devices inside the body in such a manner that causes minimal damage to surrounding tissue structures. A significant limitation of these tools is that they deprive surgeons of their traditional sense of touch, perception, and dexterity. Current systems provide visual feedback but lack the force feedback capabilities necessary to enable surgeons to reduce potential tissue damage. Force sensing capabilities were proposed for a concentric tube robot, utilizing mounted fiber Bragg grating (FBG) sensors. The system and software designs were developed along with a kinematic model for control. The FBGs were fixed onto the robot and calibrated. Experiments were then carried out to determine if the sensors were sufficiently functional. From the results obtained, the FBGs proved to be highly sensitive and sufficiently accurate in delivering force readings of the robot–tissue interactions.
Soft robotics are robotic systems made of materials that are similar in softness to human soft ti... more Soft robotics are robotic systems made of materials that are similar in softness to human soft tissues. Recent medical soft robot designs, including rehabilitation, surgical, and diagnostic soft robots, are categorized by application and reviewed for functionality. Each design is analyzed for engineering characteristics and clinical significance. Current technical challenges in soft robotics fabrication, sensor integration, and control are discussed. Future directions including portable and robust actuation power sources, clinical adoptability, and clinical regulatory issues are summarized.
The field of soft robotics has a wide array of applications, particularly in human-robotic intera... more The field of soft robotics has a wide array of applications, particularly in human-robotic interaction, from medical devices to assembly technology. In this paper, we introduce a novel design for a soft bi-directional pneumatic actuator inspired by the principles of origami. The actuator integrates a variable stiffness application using a layer jamming mechanism (LJM). LJM utilizes the effects of negative pressure on thin layers of material, providing rigidity. Incorporated into an origami bellows structure, the negative pressure causes both contractile action and stiffness, while extensive action is caused by an internal pneumatic chamber, allowing for contractile and extensive force application. Furthermore, the variable stiffness integration improved tensile force application threefold, resistance to outside linear force tenfold, and doubled sheer force resistance. The proposed origami-inspired bi-directional soft pneumatic soft actuator has immense potential to be implemented in complex biomedical applications in the near future.
Abstract Of the numerous diagnostic methods available, direct nasopharyngoscopy is perhaps the mo... more Abstract Of the numerous diagnostic methods available, direct nasopharyngoscopy is perhaps the most frequently utilized method in examining the nasopharynx for signs and symptoms associated with nasopharyngeal carcinoma (NPC). However, this method requires a trained medical practitioner and can be cumbersome. This, coupled with the fact that NPC is prevalent in individuals of Asian or Southern Chinese ancestry, is the motivation for the development of a flexible bending end-effector (BEE), aiming for an easily accessible, user-operated flexible nasopharyngoscope for transnasal explorations. The main conduits, coupled with the connector module, make up the flexible vase-spine modular design, which differentiates BEE from other preexisting flexible manipulator designs. The design rationale and verifications eventually evolve of the BEE modules. The BEE is partially automated with the joystick control interface for remote operations.
COVID-19 can induce severe respiratory problems that need prolonged mechanical ventilation in the... more COVID-19 can induce severe respiratory problems that need prolonged mechanical ventilation in the intensive care unit. While Open Tracheostomy (OT) is the preferred technique due to the excellent visualization of the surgical field and structures, Percutaneous Tracheostomy (PT) has proven to be a feasible minimally invasive alternative. However, PT's limitation relates to the inability to precisely enter the cervical trachea at the exact spot since the puncture is often performed based on crude estimation from anatomical laryngeal surface landmarks. Besides, there is no absolute control of the trajectory and force required to make the percutaneous puncture into the trachea, resulting in inadvertent injury to the cricoid ring, cervical esophagus, and vessels in the neck. Therefore, we hypothesize that a flexible mini-robotic system, incorporating the robotic needling technology, can overcome these challenges by allowing the trans-oral robotic instrument of the cervical trachea. T...
Abstract The purpose of this design project is to create transoral steerable devices with multibe... more Abstract The purpose of this design project is to create transoral steerable devices with multibending using origami-inspired techniques for tracheostomy. The modular origami joint operator (MOJO) developed in this project is a bending mechanism that uses an origami universal joint as a hinge between modules of similar shapes and different lengths. It can achieve bending angles at specific locations through mechanical actuation forces from tendons or pneumatic pressure such that it can be navigated through the oral cavity and into the trachea without the need to extend the neck or use introducers. Moreover, modules of different lengths allow for customization so that more subjects are eligible to receive tracheostomy procedures. The first part of this report will analyze the current endotracheal tubes to review their benefits and shortcomings. Next, key performance targets and step-by-step procedures for operation devices will be listed. Following this, the proposed device, MOJO, will be compared with endotracheal tubes. The last section will present a brief discussion of safety and future developments.
Surgical scene understanding is a key barrier for situation-aware robotic surgeries and the assoc... more Surgical scene understanding is a key barrier for situation-aware robotic surgeries and the associated surgical training. With the presence of domain shifts and the inclusion of new instruments and tissues, learning domain generalization (DG) plays a pivotal role in expanding instrument–tissue interaction detection to new domains in robotic surgery. Mimicking the ability of humans to incrementally learn new skills without forgetting their old skills in a similar domain, we employ incremental DG on scene graphs to predict instrument–tissue interaction during robot-assisted surgery. To achieve incremental DG, incorporate incremental learning (IL) to accommodate new instruments and knowledge-distillation-based student–teacher learning to tackle domain shifts in the new domain. Additionally, we designed an enhanced curriculum by smoothing (E-CBS) based on Laplacian of Gaussian (LoG) and Gaussian kernels, and integrated it with the feature extraction network (FEN) and graph network to im...
This paper presents a novel dynamic tactile sensor with a symmetrical longitudinal piezoelectric ... more This paper presents a novel dynamic tactile sensor with a symmetrical longitudinal piezoelectric cantilever structure, which is different from the conventional transverse cantilever structure. It has a radical size of 1.1 centimeters. A flexible hinge chain and mass probe are introduced into the structure to reduce the sensor’s natural frequency to improve the estimation accuracy of tissue hardness. Double piezoelectric patches, symmetrically distributed in the sensor, are used as the actuator to generate vibration and as the sensor for resonance detection. The sensor’s basic working principle is derived mathematically, followed by simulation verification of statics analysis for safety consideration, anisotropic vibration mode analysis, harmonic response analysis, and a calibration experiment to establish fitting curves. The threshold point is set as 192 Hz/0.6 MPa in the calibration curve, and the hardness range is divided into a soft range (0–0.6 MPa) with the sensitivity of 9.75 Hz/MPa, which could realize hardness measurement of soft tissue and normal tissue, and a hard range (which exceeds 0.6 MPa) with higher frequency to realize the identification of the lesion tissue. Finally, the sensor prototype is tested on biological tissue (fresh pig liver) to verify that the calibration curve with the selected threshold is effective for identifying lesion areas and that the sensor prototype has a function of hardness measurement with a relatively stable sensitivity and lesion identification in its operating frequency range.
2017 13th IEEE Conference on Automation Science and Engineering (CASE), 2017
The ability to sense and measure object properties based on touch is known as tactile sensing. Th... more The ability to sense and measure object properties based on touch is known as tactile sensing. The flexibility and dexterity of soft robots can be fully explored, only with efficient tactile feedback from the environment or the objects the robot interact with. This paper discusses about the development of a soft fabric based piezoresistive tactile sensor, the related calibration experiments and procedures. Fabric based sensors are flexible, stretchable and can confer to both hard and soft surfaces easily. The ability of the tactile sensor to enhance the efficiency of robotic activities is demonstrated in a simple cutting task. The robotic end effector used is a pneumatically controlled soft gripper. Experimental results show that the feedback from the tactile sensor developed is successfully used to detect the completion of the cutting task.
There are high risks of infection for surgeons during the face-to-face COVID-19 swab sampling due... more There are high risks of infection for surgeons during the face-to-face COVID-19 swab sampling due to the novel coronavirus’s infectivity. To address this issue, we propose a flexible transoral robot with a teleoperated configuration for swab sampling. The robot comprises a flexible manipulator, an endoscope with a monitor, and a master device. A 3-prismatic-universal (3-PU) flexible parallel mechanism with 3 degrees of freedom (DOF) is used to realize the manipulator’s movements. The flexibility of the manipulator improves the safety of testees. Besides, the master device is similar to the manipulator in structure. It is easy to use for operators. Under the guidance of the vision from the endoscope, the surgeon can operate the master device to control the swab’s motion attached to the manipulator for sampling. In this paper, the robotic system, the workspace, and the operation procedure are described in detail. The tongue depressor, which is used to prevent the tongue’s interference...
Disaster Medicine and Public Health Preparedness, 2021
Many countries have enacted a quick response to the unexpected coronavirus disease 2019 (COVID-19... more Many countries have enacted a quick response to the unexpected coronavirus disease 2019 (COVID-19) pandemic by using existing technologies. For example, robotics, artificial intelligence, and digital technology have been deployed in hospitals and public areas for maintaining social distancing, reducing person-to-person contact, enabling rapid diagnosis, tracking virus spread, and providing sanitation. In this study, 163 news articles and scientific reports on COVID-19-related technology adoption were screened, shortlisted, categorized by application scenario, and reviewed for functionality. Technologies related to robots, artificial intelligence, and digital technology were selected from the pool of candidates, yielding a total of 50 applications for review. Each case was analyzed for its engineering characteristics and potential impact on the COVID-19 pandemic. Finally, challenges and future directions regarding the response to this pandemic and future pandemics were summarized and...
Swabbing tests have proved to be an effective method of diagnosis for a wide range of diseases. P... more Swabbing tests have proved to be an effective method of diagnosis for a wide range of diseases. Potential occupational health hazards and reliance on healthcare workers during traditional swabbing procedures can be mitigated by self-administered swabs. Hence, we report possible methods to apply closed kinematic chain theory to develop a self-administered viral swab to collect respiratory specimens. The proposed sensorized swab models utilizing hollow polypropylene tubes possess mechanical compliance, simple construction, and inexpensive components. In detail, the adaptation of the slider-crank mechanism combined with concepts of a deployable telescopic tubular mechanical system is explored through four different oral swab designs. A closed kinematic chain on suitable material to create a developable surface allows the translation of simple two-dimensional motion into more complex multi-dimensional motion. These foldable telescopic straws with multiple kirigami cuts minimize componen...
Surgical navigation of small lumens during surgery is a challenging task, requiring expert knowle... more Surgical navigation of small lumens during surgery is a challenging task, requiring expert knowledge and dexterity. The challenge pertains to the manipulation of the distal tip (inside the patient) from the proximal end (outside the patient). Limitations in down-scaling tendon-based manipulation have led our group to investigate shape-memory-alloy, curvature-based actuation for small lumen navigation. We demonstrate two prototype designs with different approaches and characterize the deflection angles for use in surgical navigation. Nitinol wire was shape trained to memorize a particular curvature and assembled without using micro-fabrication techniques. By varying actuation voltage and control signal pulse width, we show controlled deflections ranging between 5 deg and 22 deg, which applies to surgical navigation. This concept improves distal control and makes the actuation of surgical actuators easier and safer. By varying voltage between 5.7 V to 6.3 V, we show the temperature ge...
We encapsulate Nitinol shape-memory-alloy wire in a hydrogel-matrix to fabricate a lightweight (≈... more We encapsulate Nitinol shape-memory-alloy wire in a hydrogel-matrix to fabricate a lightweight (≈1 g), self-cooling actuator (HENA) for soft robots.
Abstract Recent advances in minimally invasive surgery (MIS) have utilized a variety of equipment... more Abstract Recent advances in minimally invasive surgery (MIS) have utilized a variety of equipment, usually in the form of robotics, to aid surgeons during surgical procedures. This involves the manipulation and navigation of long tools and devices inside the body in such a manner that causes minimal damage to surrounding tissue structures. A significant limitation of these tools is that they deprive surgeons of their traditional sense of touch, perception, and dexterity. Current systems provide visual feedback but lack the force feedback capabilities necessary to enable surgeons to reduce potential tissue damage. Force sensing capabilities were proposed for a concentric tube robot, utilizing mounted fiber Bragg grating (FBG) sensors. The system and software designs were developed along with a kinematic model for control. The FBGs were fixed onto the robot and calibrated. Experiments were then carried out to determine if the sensors were sufficiently functional. From the results obtained, the FBGs proved to be highly sensitive and sufficiently accurate in delivering force readings of the robot–tissue interactions.
Soft robotics are robotic systems made of materials that are similar in softness to human soft ti... more Soft robotics are robotic systems made of materials that are similar in softness to human soft tissues. Recent medical soft robot designs, including rehabilitation, surgical, and diagnostic soft robots, are categorized by application and reviewed for functionality. Each design is analyzed for engineering characteristics and clinical significance. Current technical challenges in soft robotics fabrication, sensor integration, and control are discussed. Future directions including portable and robust actuation power sources, clinical adoptability, and clinical regulatory issues are summarized.
The field of soft robotics has a wide array of applications, particularly in human-robotic intera... more The field of soft robotics has a wide array of applications, particularly in human-robotic interaction, from medical devices to assembly technology. In this paper, we introduce a novel design for a soft bi-directional pneumatic actuator inspired by the principles of origami. The actuator integrates a variable stiffness application using a layer jamming mechanism (LJM). LJM utilizes the effects of negative pressure on thin layers of material, providing rigidity. Incorporated into an origami bellows structure, the negative pressure causes both contractile action and stiffness, while extensive action is caused by an internal pneumatic chamber, allowing for contractile and extensive force application. Furthermore, the variable stiffness integration improved tensile force application threefold, resistance to outside linear force tenfold, and doubled sheer force resistance. The proposed origami-inspired bi-directional soft pneumatic soft actuator has immense potential to be implemented in complex biomedical applications in the near future.
Abstract Of the numerous diagnostic methods available, direct nasopharyngoscopy is perhaps the mo... more Abstract Of the numerous diagnostic methods available, direct nasopharyngoscopy is perhaps the most frequently utilized method in examining the nasopharynx for signs and symptoms associated with nasopharyngeal carcinoma (NPC). However, this method requires a trained medical practitioner and can be cumbersome. This, coupled with the fact that NPC is prevalent in individuals of Asian or Southern Chinese ancestry, is the motivation for the development of a flexible bending end-effector (BEE), aiming for an easily accessible, user-operated flexible nasopharyngoscope for transnasal explorations. The main conduits, coupled with the connector module, make up the flexible vase-spine modular design, which differentiates BEE from other preexisting flexible manipulator designs. The design rationale and verifications eventually evolve of the BEE modules. The BEE is partially automated with the joystick control interface for remote operations.
COVID-19 can induce severe respiratory problems that need prolonged mechanical ventilation in the... more COVID-19 can induce severe respiratory problems that need prolonged mechanical ventilation in the intensive care unit. While Open Tracheostomy (OT) is the preferred technique due to the excellent visualization of the surgical field and structures, Percutaneous Tracheostomy (PT) has proven to be a feasible minimally invasive alternative. However, PT's limitation relates to the inability to precisely enter the cervical trachea at the exact spot since the puncture is often performed based on crude estimation from anatomical laryngeal surface landmarks. Besides, there is no absolute control of the trajectory and force required to make the percutaneous puncture into the trachea, resulting in inadvertent injury to the cricoid ring, cervical esophagus, and vessels in the neck. Therefore, we hypothesize that a flexible mini-robotic system, incorporating the robotic needling technology, can overcome these challenges by allowing the trans-oral robotic instrument of the cervical trachea. T...
Abstract The purpose of this design project is to create transoral steerable devices with multibe... more Abstract The purpose of this design project is to create transoral steerable devices with multibending using origami-inspired techniques for tracheostomy. The modular origami joint operator (MOJO) developed in this project is a bending mechanism that uses an origami universal joint as a hinge between modules of similar shapes and different lengths. It can achieve bending angles at specific locations through mechanical actuation forces from tendons or pneumatic pressure such that it can be navigated through the oral cavity and into the trachea without the need to extend the neck or use introducers. Moreover, modules of different lengths allow for customization so that more subjects are eligible to receive tracheostomy procedures. The first part of this report will analyze the current endotracheal tubes to review their benefits and shortcomings. Next, key performance targets and step-by-step procedures for operation devices will be listed. Following this, the proposed device, MOJO, will be compared with endotracheal tubes. The last section will present a brief discussion of safety and future developments.
Surgical scene understanding is a key barrier for situation-aware robotic surgeries and the assoc... more Surgical scene understanding is a key barrier for situation-aware robotic surgeries and the associated surgical training. With the presence of domain shifts and the inclusion of new instruments and tissues, learning domain generalization (DG) plays a pivotal role in expanding instrument–tissue interaction detection to new domains in robotic surgery. Mimicking the ability of humans to incrementally learn new skills without forgetting their old skills in a similar domain, we employ incremental DG on scene graphs to predict instrument–tissue interaction during robot-assisted surgery. To achieve incremental DG, incorporate incremental learning (IL) to accommodate new instruments and knowledge-distillation-based student–teacher learning to tackle domain shifts in the new domain. Additionally, we designed an enhanced curriculum by smoothing (E-CBS) based on Laplacian of Gaussian (LoG) and Gaussian kernels, and integrated it with the feature extraction network (FEN) and graph network to im...
This paper presents a novel dynamic tactile sensor with a symmetrical longitudinal piezoelectric ... more This paper presents a novel dynamic tactile sensor with a symmetrical longitudinal piezoelectric cantilever structure, which is different from the conventional transverse cantilever structure. It has a radical size of 1.1 centimeters. A flexible hinge chain and mass probe are introduced into the structure to reduce the sensor’s natural frequency to improve the estimation accuracy of tissue hardness. Double piezoelectric patches, symmetrically distributed in the sensor, are used as the actuator to generate vibration and as the sensor for resonance detection. The sensor’s basic working principle is derived mathematically, followed by simulation verification of statics analysis for safety consideration, anisotropic vibration mode analysis, harmonic response analysis, and a calibration experiment to establish fitting curves. The threshold point is set as 192 Hz/0.6 MPa in the calibration curve, and the hardness range is divided into a soft range (0–0.6 MPa) with the sensitivity of 9.75 Hz/MPa, which could realize hardness measurement of soft tissue and normal tissue, and a hard range (which exceeds 0.6 MPa) with higher frequency to realize the identification of the lesion tissue. Finally, the sensor prototype is tested on biological tissue (fresh pig liver) to verify that the calibration curve with the selected threshold is effective for identifying lesion areas and that the sensor prototype has a function of hardness measurement with a relatively stable sensitivity and lesion identification in its operating frequency range.
2017 13th IEEE Conference on Automation Science and Engineering (CASE), 2017
The ability to sense and measure object properties based on touch is known as tactile sensing. Th... more The ability to sense and measure object properties based on touch is known as tactile sensing. The flexibility and dexterity of soft robots can be fully explored, only with efficient tactile feedback from the environment or the objects the robot interact with. This paper discusses about the development of a soft fabric based piezoresistive tactile sensor, the related calibration experiments and procedures. Fabric based sensors are flexible, stretchable and can confer to both hard and soft surfaces easily. The ability of the tactile sensor to enhance the efficiency of robotic activities is demonstrated in a simple cutting task. The robotic end effector used is a pneumatically controlled soft gripper. Experimental results show that the feedback from the tactile sensor developed is successfully used to detect the completion of the cutting task.
There are high risks of infection for surgeons during the face-to-face COVID-19 swab sampling due... more There are high risks of infection for surgeons during the face-to-face COVID-19 swab sampling due to the novel coronavirus’s infectivity. To address this issue, we propose a flexible transoral robot with a teleoperated configuration for swab sampling. The robot comprises a flexible manipulator, an endoscope with a monitor, and a master device. A 3-prismatic-universal (3-PU) flexible parallel mechanism with 3 degrees of freedom (DOF) is used to realize the manipulator’s movements. The flexibility of the manipulator improves the safety of testees. Besides, the master device is similar to the manipulator in structure. It is easy to use for operators. Under the guidance of the vision from the endoscope, the surgeon can operate the master device to control the swab’s motion attached to the manipulator for sampling. In this paper, the robotic system, the workspace, and the operation procedure are described in detail. The tongue depressor, which is used to prevent the tongue’s interference...
Disaster Medicine and Public Health Preparedness, 2021
Many countries have enacted a quick response to the unexpected coronavirus disease 2019 (COVID-19... more Many countries have enacted a quick response to the unexpected coronavirus disease 2019 (COVID-19) pandemic by using existing technologies. For example, robotics, artificial intelligence, and digital technology have been deployed in hospitals and public areas for maintaining social distancing, reducing person-to-person contact, enabling rapid diagnosis, tracking virus spread, and providing sanitation. In this study, 163 news articles and scientific reports on COVID-19-related technology adoption were screened, shortlisted, categorized by application scenario, and reviewed for functionality. Technologies related to robots, artificial intelligence, and digital technology were selected from the pool of candidates, yielding a total of 50 applications for review. Each case was analyzed for its engineering characteristics and potential impact on the COVID-19 pandemic. Finally, challenges and future directions regarding the response to this pandemic and future pandemics were summarized and...
Swabbing tests have proved to be an effective method of diagnosis for a wide range of diseases. P... more Swabbing tests have proved to be an effective method of diagnosis for a wide range of diseases. Potential occupational health hazards and reliance on healthcare workers during traditional swabbing procedures can be mitigated by self-administered swabs. Hence, we report possible methods to apply closed kinematic chain theory to develop a self-administered viral swab to collect respiratory specimens. The proposed sensorized swab models utilizing hollow polypropylene tubes possess mechanical compliance, simple construction, and inexpensive components. In detail, the adaptation of the slider-crank mechanism combined with concepts of a deployable telescopic tubular mechanical system is explored through four different oral swab designs. A closed kinematic chain on suitable material to create a developable surface allows the translation of simple two-dimensional motion into more complex multi-dimensional motion. These foldable telescopic straws with multiple kirigami cuts minimize componen...
Surgical navigation of small lumens during surgery is a challenging task, requiring expert knowle... more Surgical navigation of small lumens during surgery is a challenging task, requiring expert knowledge and dexterity. The challenge pertains to the manipulation of the distal tip (inside the patient) from the proximal end (outside the patient). Limitations in down-scaling tendon-based manipulation have led our group to investigate shape-memory-alloy, curvature-based actuation for small lumen navigation. We demonstrate two prototype designs with different approaches and characterize the deflection angles for use in surgical navigation. Nitinol wire was shape trained to memorize a particular curvature and assembled without using micro-fabrication techniques. By varying actuation voltage and control signal pulse width, we show controlled deflections ranging between 5 deg and 22 deg, which applies to surgical navigation. This concept improves distal control and makes the actuation of surgical actuators easier and safer. By varying voltage between 5.7 V to 6.3 V, we show the temperature ge...
We encapsulate Nitinol shape-memory-alloy wire in a hydrogel-matrix to fabricate a lightweight (≈... more We encapsulate Nitinol shape-memory-alloy wire in a hydrogel-matrix to fabricate a lightweight (≈1 g), self-cooling actuator (HENA) for soft robots.
Uploads
Papers by Hongliang Ren