Ultra-soft and highly stretchable tissue-adhesive hydrogel based multifunctional implantable sensor for monitoring of overactive bladder

A highly stretchable and tissue-adhesive multifunctional sensor based on structurally engineered islets embedded in ultra-soft hydrogel is reported for monitoring of bladder activity in overactive bladder (OAB) induced rat and anesthetized pig. The use of hydrogel yielded a much lower sensor modulus (1 kPa) compared to that of the bladder (300 kPa), while the strong adhesiveness of the hydrogel (adhesive strength: 260.86 N/m) allowed firm attachment onto the bladder. The change in resistance of printed liquid metal particle thin-film lines under strain were used to detect bladder inflation and deflation; due to the high stretchability and reliability of the lines, surface strains of 200% could be measured repeatedly. Au electrodes coated with Platinum black were used to detect electromyography (EMG). These electrodes were placed on structurally engineered rigid islets so that no interfacial fracture occurs under high strains associated with bladder expansion. On the OAB induced rat, stronger signals (change in resistance and EMG root-mean-square) were detected near intra-bladder pressure maxima, thus showing correlation to bladder activity. Moreover, using robot-assisted laparoscopic surgery, the sensor was placed onto the bladder of an anesthetized pig. Under voiding and filling, bladder strain and EMG were once again monitored. These results confirm that our proposed sensor is a highly feasible, clinically relevant implantable device for continuous monitoring OAB for diagnosis and treatment.

Endoscopic surgery robot that facilitates insertion of the curved colon and ensures positional stability against external forces: K-COLON

BACKGROUND

Although various endoscopic surgery robots developed in previous studies are versatile and have high lesion accessibility, they have limitations in terms of reaching the target lesion through the curved path in the large intestine and providing a stable tasking environment for the operator.

METHODS

An endoscopic surgery robot was developed for performing surgery in the large intestine. The robot was easily inserted into the target lesion in the curved colon through the mounted soft actuator and demonstrated high structural stiffness through the insertion of the sigmoidal auxiliary tendons.

RESULTS

The robot was able to access the target lesion in the curved colon through teleoperation alone. Further, it was confirmed that the high structural stiffness overtube improved the overall task performance in the user test.

CONCLUSIONS

The proposed robotic system demonstrated the possibility and potential of performing advanced endoscopic surgery in the large intestine.

In Vivo Feasibility Test of a New Flexible Ureteroscopic Robotic System, easyUretero, for Renal Stone Retrieval in a Porcine Model

PURPOSE

Using a new robotic endoscopic platform system developed for retrograde intrarenal surgery (RIRS) called easyUretero (ROEN Surgical Inc.), we evaluated the feasibility and safety of renal stone retrieval in a porcine model.

MATERIALS AND METHODS

Six female pigs were used for our in vivo study. First, 0.3-cm-sized phantom stones were inserted into the kidneys of each pig via the ureteral access sheath. Next, renal stone retrieval was attempted using manual RIRS in three pigs and robotic RIRS in three pigs. Three surgeons performed extraction of 10 stones in each session.

RESULTS

The mean stone retrieval time by manual RIRS was significantly shorter than that by robotic RIRS (399.9±185.4 sec vs. 1127.6±374.5 sec, p=0.001). In contrast, the questionnaire regarding usability showed high satisfaction in the surgeons' fatigue category for surgeons using robotic RIRS. The radiation exposure dose was also lower in robotic RIRS than in manual RIRS (0.14 µSv vs. 45.5 µSv). Postoperative ureteral injury assessment revealed Grade 0 in manual RIRS cases and Grades 0, 1, and 2 in robotic RIRS cases.

CONCLUSION

The easyUretero system is a new robotic RIRS system that was developed in Korea. The results of the present study suggest that using easyUretero for stone retrieval during RIRS is safe and ergonomic.

Feasibility of Laser Lithotripsy for Midsize Stones Using Robotic Retrograde Intrarenal Surgery System easyUretero in a Porcine Model

Purpose: To test the safety and feasibility of laser lithotripsy for midsize renal stones using a newly developed robotic retrograde intrarenal surgery (RIRS) system (easyUretero) in a porcine model. Materials and Methods: Three urologic surgeons representing three different RIRS experience levels (beginner, intermediate, and expert) participated. Four female pigs (aged 6 months) underwent manual or robotic RIRS. Under general anesthesia, a nephrostomy tract was created ventrally, and calcium stones (diameter, 1.0-1.5 cm) were inserted at renal calices. For manual RIRS, surgeons operated a flexible ureteroscope. For robotic RIRS, the ureteroscope was attached to the robotic slave device. The Auriga XL™ Holmium laser was used for lithotripsy. Lasering and stone retrieval time were measured. Kidneys and ureters were inspected for injury at the end of each session. Results: For the expert, both lasering and stone retrieval by manual RIRS were quicker than by robotic RIRS (22.8 ± 11.0 s/stone vs 234.5 ± 102.5 s/stone, p = 0.02; 41.5 ± 0.5 s/stone vs 79.3 ± 8.1 s/stone, p = 0.02). For the intermediate and beginner, lasering and stone retrieval times were not significantly different between manual and robotic procedures (127.8 ± 93.2 s/stone vs 284.8 ± 112.3 s/stone, p = 0.08; 86.0 ± 30.5 s/stone vs 84.1 ± 21.4 s/stone, p = 0.92). All stones were removed. Grade 1 ureteral and renal injuries occurred in both manual RIRS and robotic RIRS. Conclusions: The laser lithotripsy using the easyUretero robotic system is safe and feasible in a porcine model, even for less-experienced surgeons.

Sigmoidal Auxiliary Tendon-Driven Mechanism Reinforcing Structural Stiffness of Hyper-Redundant Manipulator for Endoscopic Surgery

The overtube of an endoscopic surgery robot is fixed when performing tasks, unlike those of commercial endoscopes, and this overtube should have high structural stiffness after reaching the target lesion so that sufficient tension can be applied to the lesion tissue with the surgical tool and there are fewer changes in the field of view of the endoscopic camera from this reaction force. Various methods have been proposed to reinforce the structural stiffnesses of hyper-redundant manipulators. However, the safety, rapid response, space efficiency, and cost-effectiveness of these methods should be considered for use in actual clinical environments, such as the gastrointestinal tract. This study proposed a method to minimize the positional changes of the overtube end tip due to external forces using only auxiliary tendons in the optimized path without additional mechanical structures. Overall, the proposed method involved moving the overtube to the target lesion through the main driving tendon and applying tension to the auxiliary tendons to reinforce the structural stiffness. The complete system was analyzed in terms of energy, and the sigmoidal auxiliary tendons were verified to effectively reinforce the structural stiffness of the overtube consisting of rolling joints. In addition, the design guidelines of the overtube for actual endoscopic surgery were proposed considering hollowness, retroflexion, and high structural stiffness. The positional changes due to external forces were confirmed to be reduced by 60% over the entire workspace.

Analysis of tendon tension and hysteresis by tendon twisting and development of anti-twist tendon mechanism of robotic surgical instruments

BACKGROUND

Control of the joints of robotic surgical instruments is difficult owing to hysteresis, and tendon twisting due to axial rotation of surgical tools also causes hysteresis. Therefore, a new mechanism is needed to prevent tendon twisting.

METHODS

Tendon tension and hysteresis change were analyzed by observing the movement of the joint depending on whether the tendons twisted for the same input signal. An anti-twist tendon mechanism to prevent twisting was developed. A 3-mm needle driver applied with the proposed mechanism was manufactured.

RESULTS

The anti-twist mechanism makes no tension change because of twisting or friction between the tendon and the system, i.e., the operating performance was the same regardless of rotation.

CONCLUSION

The proposed mechanism has been verified and can be applied to small surgical instruments 3 mm in size. These findings can be applied in the development of instruments for precise surgeries such as microsurgery. This article is protected by copyright. All rights reserved.

A novel encountered-type master device with precise manipulation for robot-assisted microsurgery

BACKGROUND

The unconstrained master devices have emerged as attractive alternatives to the existing linkage-based counterparts. However, the conventional unconstrained master device's manipulation methods have several disadvantages in efficiency and precision.

METHODS

We propose an encountered-type master device based on an electromagnetic tracking solution with a prismatic joint at the tip, capable of continuous spatial manipulation with the tip supported on the surface. We performed path-following task and pointing tasks to analyze the performance of the master device.

RESULTS

The most convenient, efficient, accurate positioning and precise pointing were possible with a closed loop support condition. Moreover, the tasks under this condition were also completed with higher accuracy, and precision when applying lower motion scale factors.

CONCLUSIONS

The proposed master device allowed precise and accurate manipulation for microsurgical tasks. Compared with the conventional unconstrained master devices, the proposed master device provides the ability to perform precise work with a clutching-free motion.

A novel microsurgery robot mechanism with mechanical motion scalability for intraocular and reconstructive surgery

BACKGROUND

Intraocular surgery and reconstructive surgery are challenging microsurgery procedures that require two types of motion: precise motion and larger motion. To effectively perform the requisite motion using a robot, it is necessary to develop a manipulator that can adjust the scale of motion between precise motion and less precise, yet larger motion.

AIMS

In this paper, we propose a novel microsurgery robot using the dual delta structure (DDS) to mechanically scale the motion to seamlessly adjust between precise and larger motion. MATERIALS & METHODS: The DDS forms a lever mechanism that enables the motion scaling at the end-effector using two delta platforms. Seamless scale adjustment enables the robot to effectively perform various surgical moves.

RESULTS

A prototype robot system was developed to validate the effectiveness of the DDS. The experiment results in various scale settings validated the scaling mechanism of the DDS.

CONCLUSION

Through a graphical simulation and measurement experiment, the robot's precision level and attainable workspace has been confirmed adequate for intraocular and reconstructive surgery.

easyEndo robotic endoscopy system: Development and usability test in a randomized controlled trial with novices and physicians

BACKGROUND

Some difficulties are common when using endoscopes. Steering is not intuitive, the endoscope weight is a physical burden to physicians and communication problems often occur between operators.

METHOD

To overcome these, we developed a robotic endoscopy system and conducted a usability test to compare conventional and robotic manipulation. Nine novices and eighteen physicians participated with the physicians being divided into intermediate and expert groups. The participants performed endoscope insertion into a simulator (physicians) or lesion marking on a testbed (novices) and simulate biopsies.

RESULT

Novices completed the tasks faster and with a lower workload when using robotic manipulation, whereas the experts showed the opposite trend. Still, the intermediates showed no significant difference as trials proceeded. Nevertheless, the learning curve analysis showed that the learning rate in all groups is greater for robotic manipulation (21.02% on average) than for conventional manipulation (13.75%) and predicted that physicians can reach manual performance.

CONCLUSION

The proposed robotic endoscopy system may allow solo-manipulation using one controller and may be more intuitive and convenient to use than conventional manipulation.

A highly intuitive and ergonomic redundant joint master device for four-degrees of freedom flexible endoscopic surgery robot

BACKGROUND

Studies have been conducted on slave-specific master devices with a similar kinematic structure to the slave to enhance intuitiveness. However, for the four-degrees of freedom (DOFs) slave of a flexible endoscopic surgery robot, only four DOFs in the master device causes low ergonomic performance.

METHODS

To enhance ergonomic performance, a second yaw joint was added as a redundant joint after considering the range of wrist motion and the workspace shape. Three experiments were performed to compare the intuitiveness and ergonomic performance of the proposed device with four-DOFs slave-specific and six-DOFs general-purpose master devices.

RESULTS

Significant differences were observed in terms of intuitiveness performance between the slave-specific and the general-purposed master device. On the other hand, there was no significant difference in ergonomic performance between the master devices with redundant joint.

CONCLUSIONS

Compared with a general-purpose master device, the proposed one exhibited noticeably improved intuitiveness performance and comparable ergonomic performance.

Evaluation of a robotic arm-assisted endoscope to facilitate endoscopic submucosal dissection (with video)

BACKGROUND AND AIMS

Endoscopic submucosal dissection (ESD) is considered technically difficult and challenging using a conventional flexible endoscope, mainly due to the lack of proper countertraction to expose the submucosal dissection plane. This study aimed to evaluate the feasibility of a traction method using a dexterous robotic arm in ex vivo gastric ESD.

METHODS

ESD was performed in a total of 45 procedures using a portable endoscopic tool handler (PETH) (n = 30) and using the conventional method (n = 15) at various locations in the stomach. For each procedure, the performance data were recorded, including the total procedure time (minutes), incision time (minutes), dissection speed (mm²/minute), and blind dissection rate (%), to enable a comparison of the 2 ESD methods.

RESULTS

The total procedure time was significantly shorter with PETH-ESD than in conventional ESD (23 vs 36 minutes, P = .011). This result is mainly attributed to the dissection speed, which was significantly faster, by more than 2.5 times, using the PETH (122.3 ± 76.5 vs 47.5 ± 26.9 mm²/minute, P < .001). The blind dissection rate was greatly decreased in PETH-ESD (0 vs 20%, P < .001). There was no significant difference in the incision time (6.1 ± 5.0 vs 5.5 ± 2.9 min, P = .612).

CONCLUSIONS

The countertraction method using the PETH significantly improved the dissection speed and reduced blind dissection by enhancing direct visualization of the submucosal plane. With the advantages of multidirectional traction, fine tension control, and regrasping, this new device is expected to improve the performance of ESD and further facilitate advanced endoscopic procedures.

Braille Display for Portable Device Using Flip-Latch Structured Electromagnetic Actuator

We propose an electromagnetic-based braille display that can represent two-dimensional information. The key principle is a flip-latch structure, which allows satisfying requirements of both protrusion force for braille recognition and low power consumption. A magnet-inserted flip-latch has an eccentric shape, and is driven by and flips over the protruded voice coil and pushing the braille pin. Then it acts as a latch to lock and maintain the pin protrusion without additional energy consumption. We manufacture braille display modules and arrange them into a braille display with a total of 192 pins (16 columns and 12 rows). The pin-to-pin spacing is 2.5 mm, and the thickness of the display is about 5.5 mm. Each pin can switch states in 5 ms of operating time with 1W of power. In this paper, we describe the design and operating mechanism of the proposed actuator and perform operation tests to obtain stable driving conditions for the display. Finally, applications and limitations of the proposed braille display are analyzed.

Effect of backlash hysteresis of surgical tool bending joints on task performance in teleoperated flexible endoscopic robot

BACKGROUND

The tendon-sheath mechanism provides flexibility but degrades the task performance of the flexible endoscopic robot because of the inherent backlash hysteresis problem. Previous studies have only focused on reducing backlash hysteresis. The goal of this study is to identify the backlash hysteresis criteria of surgical tool bending joints to maintain efficient surgical performance.

METHODS

A test platform for a surgical tool has been developed that has initial backlash hysteresis under 5° and can adjust the backlash hysteresis intentionally. Performance variation has been investigated in three bench-top endoscopic tasks in which various backlash hysteresis conditions were intentionally adjusted.

RESULTS

A clear drop-off in task performance has been observed when the backlash hysteresis of the bending joints was greater than 10° regardless of the type of task and link length.

CONCLUSIONS

The backlash hysteresis of surgical tool bending joints should be reduced to at least 10° to maintain efficient performance in robotic endoscopic surgery.

Mechanical Vibration Influences the Perception of Electrovibration

Recently, various methods using, simultaneously, two types of tactile feedback have been proposed to emulate a real object. However, the possible masking effect when providing two types of tactile feedback has been scarcely reported. In this study, we investigated the masking effect caused by mechanical vibration on the perception of electrovibration. The absolute and difference thresholds of the electrovibration were measured according to the presence/absence, frequency, and intensity of the mechanical vibration. The absolute threshold of electrovibration tended to increase in the form of a ramp function, as the intensity of the masking stimulus (mechanical vibration) increased. Particularly, the masking effect was more remarkable when the frequency of both the target and the masking stimulus was the same (up to 13 dB increase with 25 dB SL masker). Furthermore, the difference in the threshold (average of 1.21 dB) did not significantly change due to the masking stimulus, when the sensation level intensity of the target stimulus was within the section following the Weber’s law. The results further indicated that electrovibration contributes to the activation of slowly adapting afferents as well. This investigation will provide important guidelines for the design of haptic interface that employs multiple types of tactile feedback.

Haptic Rendering of 3D Geometry on 2D Touch Surface Based on Mechanical Rotation

In this paper, we present a robotic surface display that physically imitates the orientation of virtual 3D geometry touched through a 2D flat screen. The proposed approach renders the surface orientation of 3D geometry such that users can tactually obtain relative geometric information, which plays a significant role in the process of real-world haptic object perception. Taking advantage of the planar aspect of touch surfaces, the system constructs a rotation matrix to control the pose of a surface with minimal mechanical movements with given partial geometric information (i.e., normal vector at the point of touch). To evaluate the proposed rendering scheme, we conducted a geometric task (two alternative forced choices) with a set of hand-sized cylindrically curved geometries in which participants were asked to identify which of the two surfaces they perceived as being more curved. Curvatures with the same polarities (i.e., convex-convex and concave-concave) were employed in the study and psychometric curves estimated to obtain the threshold of the curvature difference and to validate the proposed rendering scheme. Possible applications of the proposed system and its limitations are also presented.

A single port surgical robot system with novel elbow joint mechanism for high force transmission

BACKGROUND

Despite its evident clinical benefits, single-incision laparoscopic surgery (SILS) imposes inherent limitations of collision between external arms and inadequate triangulation because multiple instruments are inserted through a single port at the same time.

METHODS

A robot platform appropriate for SILS was developed wherein an elbowed instrument can be equipped to easily create surgical triangulation without the interference of robot arms. A novel joint mechanism for a surgical instrument actuated by a rigid link was designed for high torque transmission capability.

RESULTS

The feasibility and effectiveness of the robot was checked through three kinds of preliminary tests: payload, block transfer, and ex vivo test. Measurements showed that the proposed robot has a payload capability >15 N with 7 mm diameter.

CONCLUSIONS

The proposed robot is effective and appropriate for SILS, overcoming inadequate triangulation and improving workspace and traction force capability.

Modeling and test of a kinaesthetic actuator based on MR fluid for haptic applications

Haptic display units have been widely used for conveying button sensations to users, primarily employing vibrotactile actuators. However, the human feeling for pressing buttons mainly relies on kinaesthetic sensations (rather than vibrotactile sensations), and little studies exist on small-scale kinaesthetic haptic units. Thus, the primary goals of this paper are to design a miniature kinaesthetic actuator based on Magneto-Rheological (MR) fluid that can convey various button-clicking sensations and to experimentally evaluate its haptic performance. The design focuses of the proposed actuator were to produce sufficiently large actuation forces (resistive forces) for human users in a given size constraint and to offer a wide range of actuation forces for conveying vivid haptic sensations to users. To this end, this study first performed a series of parametric studies using mathematical force models for multiple operating modes of MR fluid in conjunction with finite element electromagnetism analysis. After selecting design parameters based on parametric studies, a prototype actuator was constructed, and its performance was evaluated using a dynamic mechanical analyzer. It measured the actuator's resistive force with a varying stroke (pressed depth) up to 1 mm and a varying input current from 0 A to 200 mA. The results show that the proposed actuator creates a wide range of resistive forces from around 2 N (off-state) to over 9.5 N at 200 mA. In order to assess the prototype's performance in the terms of the haptic application prospective, a maximum force rate was calculated to determine just noticeable difference in force changes for the 1 mm stoke of the actuator. The results show that the force rate is sufficient to mimic various levels of button sensations, indicating that the proposed kinaesthetic actuator can offer a wide range of resistive force changes that can be conveyed to human operators.

Stability and Performance of Haptic Interfaces with Active/Passive Actuators—Theory and Experiments

This paper addresses both theoretical and experimental studies of the stability and performance of haptic interfaces containing active/passive actuators. Three different realizations of haptic interfaces are introduced to investigate their stability and performance: an active system equipped with a motor; a passive system equipped with a brake; and a hybrid system equipped with both brake and motor. The first objective is to demonstrate that a hybrid system is superior in its stability and performance to an active system via passivity theorem and Z-width. The second objective of this paper is to show that the conditions for the asymptotic stability of haptic interfaces during the static friction display are investigated via the absolute stability theory. Theoretical and experimental results are compared. An alternative haptic interface is proposed that provides its highly stable haptic interaction with high performance.

Surgical robot system for single-port surgery with novel joint mechanism

Single-port surgery is a new surgical method performed by inserting several surgical tools and a laparoscope through an umbilical incision. Compared with conventional laparoscopic surgery, the smaller incision in this procedure produces a lower amount of trauma, which leads to shorter hospitalization. However, with the current laparoscopic tools and surgical robots, the surgeon must overcome several difficulties, such as a limited range of motion and collisions between the surgical instruments and the laparoscope. This paper proposes a new surgical robot system for single-port surgery that uses a novel joint mechanism. The proposed joint mechanism is suitable for surgical instruments with multiple degrees of freedom (DOF). Thus, it can prevent hysteresis of the joint and achieve more accurate motion with a large force. A 6-DOF surgical instrument with this joint mechanism can avoid collisions between surgical tools or arms and approach the surgical target more easily than a conventional straight surgical tool. The external arm with 2-DOF passive joints can extend the workspace of the system during surgery. Preliminary tests and validations were performed with a prototype of the system.

Morbidity and mortality of the Hartmann procedure for diverticular disease over 18 years in a single institution

AIM

Hartmann's procedure for perforated diverticulitis is associated with substantial morbidity and mortality. This study analyses factors associated with morbidity/mortality and possible changes over time.

METHOD

Patients treated by urgent Hartmann's procedure for perforated diverticulitis between 1992 and 2010 were studied, and information was collected on age, sex, perioperative details, 30-day morbidity and mortality recorded in an institutional review board approved database supplemented by chart review. Patients were divided into four groups based on the year of surgery. Univariate and multivariate logistic regression analysis was performed to identify risk factors associated with morbidity and mortality.

RESULTS

In all, 199 patients (51% female, mean age 65 years, mean body mass index 28 kg/m(2)) were identified. The American Society of Anesthesiologists (ASA) score was 4 in 30% of patients and Hinchey Stage IV in 16%. The mean length of stay was 12.5 ± 10 days. Mortality was 15% and did not change significantly over time. Overall morbidity was 52% and significantly increased over time on univariate analysis (P = 0.007) but not on multivariate analysis (P = 0.11). Independent predictors of morbidity on multivariate analysis were Hinchey IV (P < 0.001) and hypoproteinaemia (P = 0.001). Independent predictors for mortality were ASA > 3 (P = 0.01), abnormal creatinine (P = 0.007), steroid use (P = 0.007), Hinchey IV (P = 0.032), low albumin (P < 0.001) and low body mass index (P = 0.001).

CONCLUSION

Mortality after Hartmann's procedure for perforated diverticulitis has not decreased during the last 18 years. Morbidity has actually increased over time although this is related to increased disease severity and comorbidity. Future efforts should focus on the identification of patient subgroups benefiting from earlier elective surgery and alternative surgical approaches when perforated diverticulitis does occur.

Effect of frequency difference on sensitivity of beats perception

Two vibrations with slightly different frequencies induce the beats phenomenon. In tactile perception, when two pins of different frequencies stimulate the fingertips, an individual perceives a beats caused by a summation stimulus of the two vibrations. The present study demonstrates experimentally that humans can perceive another vibration based on the beats phenomenon when two tactile stimuli with slightly different frequencies are stimulated on the finger pad with a small contactor in different locations at the same time. Moreover, we examined the amplitude of the detection threshold to be able to perceive beats phenomenon on the index finger with 5 carrier frequency (63.1, 100, 158.5, 251.2, and 398.1 Hz) and 4 beats frequency (2.5, 3.98, 6.31, and 10 Hz) when two stimuli 1 mm distance apart are vibrated at a slightly different frequency. From the experiments, it is concluded that the amplitude threshold to be able to perceive beats decreases as the standard frequency increases under 398 Hz. Furthermore, from comparing the absolute detection threshold and beats detection threshold, as the carrier frequency increases, the required amplitude at two pins for the detection of beats decreases compared to absolute vibration.

An anatomic study on the junctura tendinum in the 4th intermetacarpal space and its clinical implication

We report results of anatomic study in the fourth intermetacarpal space, focusing on the pattern of junctura tendinum and variations of extensor tendons of the little finger with its clinical implication on snapping of the little finger. Fifty unpaired cadaveric hands were dissected from the wrist to the middle phalanx of the ring and little fingers. The type of junctura tendinum was judged based on Von Schroder's classification and the relationship with EDC were recorded. EDC to the little finger and EDM were dissected and the numbers were recorded. Forty six hands (92%) exhibited a junctura tendinum in the fourth intermetacarpal space and it was Type III in 42 hands (84%). The EDC-little finger was absent in 76% (38 of 50 hands). When present, EDC-little finger originated most commonly as single thin tendon. The absence of an EDC-little finger was associated with increased incidence of Type III junctura tendinum (37 of 38 hands). An EDM was present in all 50 hands running from the fifth dorsal compartment. Based on these clinical and anatomic studies, we considered that the snapping of the little finger is more likely subluxation of junctura tendinum rather than subluxation/dislocation of EDC of the little finger.

Evolutionary programming-based univector field navigation method for past mobile robots

Most of navigation techniques with obstacle avoidance do not consider the robot orientation at the target position. These techniques deal with the robot position only and are independent of its orientation and velocity. To solve these problems this paper proposes a novel univector field method for fast mobile robot navigation which introduces a normalized two dimensional vector field. The method provides fast moving robots with the desired posture at the target position and obstacle avoidance. To obtain the sub-optimal vector field, a function approximator is used and trained by evolutionary programming. Two kinds of vector fields are trained, one for the final posture acquisition and the other for obstacle avoidance. Computer simulations and real experiments are carried out for a fast moving mobile robot to demonstrate the effectiveness of the proposed scheme.