Soft tissue characterisation using a force feedback-enabled instrument for robotic assisted minimally invasive surgery systems

An automated laparoscopic instrument capable of non-invasivemeasurement of tip/tissue interaction forces for direct application in robotic assisted minimally invasive surgery systems is introduced in this chapter. It has the capability to measure normal grasping forces as well as lateral interaction forces without any sensor mounted on the tip jaws. Further to non-invasive actuation of the tip, the proposed instrument is also able to change the grasping direction during surgical operation. Modular design of the instrument allows conversion between surgical modalities (e.g., grasping, cutting, and dissecting). The main focus of thispaper is on evaluation of the grasping force capability of the proposed instrument. The mathematical formulation of fenestrated insert is presented and its non-linear behaviour is studied. In order to measure the stiffness of soft tissues, a device was developed that is also described in this chapter. Tissue characterisation experiments were conducted and results are presented and analysed here. The experimental results verify the capability of the proposed instrument in accurately measuring grasping forces and in characterising artificial tissue samples of varying stiffness.

Motion analysis of a robotic assisted surgery and microsurgery system - experimental verification

Motion analysis of a parallel robot assisted minimally invasive surgery/microsurgery system (PRAMiSS) and the control structures enabling it to achieve milli/micromanipulations under the constraint of moving through a fixed penetration point or so-called remote centre-of-motion (RCM) are presented in this article. Two control algorithms are proposed suitable for minimally invasive surgery (MIS) with submillimeter accuracy and for minimally invasive micro-surgery (MIMS) with submicrometer accuracy. The RCM constraint is performed without having any mechanical constraint. Control algorithms also apply orientation constraint preventing the tip to orient relative to the soft tissues due to the robot movements. Experiments were conducted to verify accuracy and effectiveness of the proposed control algorithms for MIS and MIMS operations. The experimental results demonstrate accuracy and performance of the proposed position control algorithms.

Force measurement capability for robotic assisted minimally invasive surgery systems

An automated laparoscopic instrument capable of non-invasive measurement of tip/tissue interaction forces for direct application in robotic assisted minimally invasive surgery systems_ is introduced in this paper. It has the capability to measure normal grasping forces as well as lateral interaction forces without any sensor mounted on the tip jaws. Further to non-invasive actuation of the tip, the proposed instrument is also able to change the grasping direction during surgical operation. Modular design of the instrument allows conversion between surgical modalities (e.g., grasping, cutting, and dissecting). The main focus of this paper is on evaluation of the grasping force capability of the proposed instrument. The mathematical formulation of fenestrated insert is presented and its non-linear behaviour is studied. In order to measure the stiffness of soft tissues, a device was developed that is also described in this paper. Tissue characterisation experiments were conducted and results are presented and analysed here. The experimental results verify the capability of the proposed instrument in accurately measuring grasping forces and in characterising artificial tissue samples of varying stiffness.

Tumour but not stromal expression of β3 integrin is essential, and is required early, for spontaneous dissemination of bone-metastatic breast cancer.

Although many preclinical studies have implicated β3 integrin receptors (αvβ3 and αIIbβ3) in cancer progression, β3 inhibitors have shown only modest efficacy in patients with advanced solid tumours. The limited efficacy of β3 inhibitors in patients could arise from our incomplete understanding of the precise function of β3 integrin and, consequently, inappropriate clinical application. Data from animal studies are conflicting and indicate heterogeneity with respect to the relative contributions of β3-expressing tumour and stromal cell populations in different cancers. Here we aimed to clarify the function and relative contributions to metastasis of tumour versus stromal β3 integrin in clinically relevant models of spontaneous breast cancer metastasis, with particular emphasis on bone metastasis. We show that stable down-regulation of tumour β3 integrin dramatically impairs spontaneous (but not experimental) metastasis to bone and lung without affecting primary tumour growth in the mammary gland. Unexpectedly, and in contrast to subcutaneous tumours, orthotopic tumour vascularity, growth and spontaneous metastasis were not altered in mice null for β3 integrin. Tumour β3 integrin promoted migration, protease expression and trans-endothelial migration in vitro and increased vascular dissemination in vivo, but was not necessary for bone colonization in experimental metastasis assays. We conclude that tumour, rather than stromal, β3 expression is essential and is required early for efficient spontaneous breast cancer metastasis to bone and soft tissues. Accordingly, differential gene expression analysis in cohorts of breast cancer patients showed a strong association between high β3 expression, early metastasis and shorter disease-free survival in patients with oestrogen receptor-negative tumours. We propose that β3 inhibitors may be more efficacious if used in a neoadjuvant setting, rather than after metastases are established. Copyright © 2014 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Muscle atrophy and changes in spinal morphology: is the lumbar spine vulnerable after prolonged bed-rest?

STUDY DESIGN: prospective longitudinal study. OBJECTIVE: to evaluate the effect of bed-rest on the lumbar musculature and soft-tissues. SUMMARY OF BACKGROUND DATA: earlier work has suggested that the risk of low back injury is higher after overnight bed-rest or spaceflight. Changes in spinal morphology and atrophy in musculature important in stabilizing the spine could be responsible for this, but there are limited data on how the lumbar musculature and vertebral structures are affected during bed-rest. METHODS: nine male subjects underwent 60-days head-down tilt bed-rest as part of the second Berlin Bed-Rest Study. Disc volume, intervertebral spinal length, intervertebral lordosis angle, and disc height were measured on sagittal plane magnetic resonance images. Axial magnetic resonance images were used to measure cross-sectional areas (CSAs) of the multifidus (MF), erector spinae, quadratus lumborum, and psoas from L1 to L5. Subjects completed low back pain (LBP) questionnaires for the first 7-days after bed-rest. RESULTS: increases in disc volume, spinal length (greatest at lower lumbar spine), loss of the lower lumbar lordosis, and move to a more lordotic position at the upper lumbar spine (P < 0.0097) were seen. The CSAs of all muscles changed (P < 0.002), with the rate of atrophy greatest at L4 and L5 in MF (P < 0.002) and at L1 and L2 in the erector spinae (P = 0.0006). Atrophy of the quadratus lumborum was consistent throughout the muscle (P = 0.15), but CSA of psoas muscle increased (P < 0.0001). Subjects who reported LBP after bed-rest showed, before reambulation, greater increases in posterior disc height, and greater losses of MF CSA at L4 and L5 than subjects who did not report pain (all P < 0.085). CONCLUSION: these results provide evidence that changes in the lumbar discs during bed-rest and selective atrophy of the MF muscle may be important factors in the occurrence of LBP after prolonged bed-rest.

Canadian Society for Exercise Physiology position stand : the use of instability to train the core in athletic and nonathletic conditioning

The use of instability devices and exercises to train the core musculature is an essential feature of many training centres and programs. It was the intent of this position stand to provide recommendations regarding the role of instability in resistance training programs designed to train the core musculature. The core is defined as the axial skeleton and all soft tissues with a proximal attachment originating on the axial skeleton, regardless of whether the soft tissue terminates on the axial or appendicular skeleton. Core stability can be achieved with a combination of muscle activation and intra-abdominal pressure. Abdominal bracing has been shown to be more effective than abdominal hollowing in optimizing spinal stability. When similar exercises are performed, core and limb muscle activation are reported to be higher under unstable conditions than under stable conditions. However, core muscle activation that is similar to or higher than that achieved in unstable conditions can also be achieved with ground-based free-weight exercises, such as Olympic lifts, squats, and dead lifts. Since the addition of unstable bases to resistance exercises can decrease force, power, velocity, and range of motion, they are not recommended as the primary training mode for athletic conditioning. However, the high muscle activation with the use of lower loads associated with instability resistance training suggests they can play an important role within a periodized training schedule, in rehabilitation programs, and for nonathletic individuals who prefer not to use ground-based free weights to achieve musculoskeletal health benefits.

The use of instability to train the core musculature

Training of the trunk or core muscles for enhanced health, rehabilitation, and athletic performance has received renewed emphasis. Instability resistance exercises have become a popular means of training the core and improving balance. Whether instability resistance training is as, more, or less effective than traditional ground-based resistance training is not fully resolved. The purpose of this review is to address the effectiveness of instability resistance training for athletic, nonathletic, and rehabilitation conditioning. The anatomical core is defined as the axial skeleton and all soft tissues with a proximal attachment on the axial skeleton. Spinal stability is an interaction of passive and active muscle and neural subsystems. Training programs must prepare athletes for a wide variety of postures and external forces, and should include exercises with a destabilizing component. While unstable devices have been shown to be effective in decreasing the incidence of low back pain and increasing the sensory efficiency of soft tissues, they are not recommended as the primary exercises for hypertrophy, absolute strength, or power, especially in trained athletes. For athletes, ground-based free-weight exercises with moderate levels of instability should form the foundation of exercises to train the core musculature. Instability resistance exercises can play an important role in periodization and rehabilitation, and as alternative exercises for the recreationally active individual with less interest or access to ground-based free-weight exercises. Based on the relatively high proportion of type I fibers, the core musculature might respond well to multiple sets with high repetitions (e.g., >15 per set); however, a particular sport may necessitate fewer repetitions.

Evolution of 3D printed soft actuators

Developing soft actuators and sensors by means of 3D printing has become an exciting research area. Compared to conventional methods, 3D printing enables rapid prototyping, custom design, and single-step fabrication of actuators and sensors that have complex structure and high resolution. While 3D printed sensors have been widely reviewed in the literature, 3D printed actuators, on the other hand, have not been adequately reviewed thus far. This paper presents a comprehensive review of the existing 3D printed actuators. First, the common processes used in 3D printing of actuators are reviewed. Next, the existing mechanisms used for stimulating the printed actuators are described. In addition, the materials used to print the actuators are compared. Then, the applications of the printed actuators including soft-manipulation of tissues and organs in biomedicine and fragile agricultural products, regenerative design, smart valves, microfluidic systems, electromechanical switches, smart textiles, and minimally invasive surgical instruments are explained. After that, the reviewed 3D printed actuators are discussed in terms of their advantages and disadvantages considering power density, elasticity, strain, stress, operation voltage, weight, size, response time, controllability, and biocompatibility. Finally, the future directions of 3D printed actuators are discussed.