scholarly journals Smart surgical sutures using soft artificial muscles

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Phuoc Thien Phan ◽  
Trung Thien Hoang ◽  
Mai Thanh Thai ◽  
Harrison Low ◽  
James Davies ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Research Training ◽  
Fluid Pressure ◽  
Artificial Muscle ◽  
Physical Structure ◽  
Tension Distribution ◽  
Locking Mechanism ◽  
Core Technology ◽  
Surgical Sutures ◽  
Surgical Field

AbstractWound closure with surgical sutures is a critical challenge for flexible endoscopic surgeries. Substantial efforts have been introduced to develop functional and smart surgical sutures to either monitor wound conditions or ease the complexity of knot tying. Although research interests in smart sutures by soft robotic technologies have emerged for years, it is challenging to develop a soft robotic structure that possesses a similar physical structure as conventional sutures while offering a self-tightening knot or anchor to close the wound. This paper introduces a new concept of smart sutures that can be programmed to achieve desired and uniform tension distribution while offering self-tightening knots or automatically deploying secured anchors. The core technology is a soft hydraulic artificial muscle that can be elongated and contracted under applied fluid pressure. Each suture is equipped with a pressure locking mechanism to hold its temporary elongated state and to induce self-shrinking ability. The puncturing and holding force for the smart sutures with anchors are examined. Ex-vivo experiments on fresh porcine stomach and colon demonstrate the usefulness of the new smart sutures. The new approaches are expected to pave the way for the further development of smart sutures that will benefit research, training, and commercialization in the surgical field.

scholarly journals Performance of microvascular anastomosis with a new robotic visualization system: proof of concept

2021 ◽  
Author(s):  
F. Boehm ◽  
P. J. Schuler ◽  
R. Riepl ◽  
L. Schild ◽  
T. K. Hoffmann ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Body Position ◽  
Head Movements ◽  
Camera System ◽  
Visualization System ◽  
Head Mounted Display ◽  
General Evaluation ◽  
Surgical Field ◽  
Technical Instructions

AbstractMicrovascular procedures require visual magnification of the surgical field, e.g. by a microscope. This can be accompanied by an unergonomic posture with musculoskeletal pain or long-term degenerative changes as the eye is bound to the ocular throughout the whole procedure. The presented study describes the advantages and drawbacks of a 3D exoscope camera system. The RoboticScope®-system (BHS Technologies®, Innsbruck, Austria) features a high-resolution 3D-camera that is placed over the surgical field and a head-mounted-display (HMD) that the camera pictures are transferred to. A motion sensor in the HMD allows for hands-free change of the exoscope position via head movements. For general evaluation of the system functions coronary artery anastomoses of ex-vivo pig hearts were performed. Second, the system was evaluated for anastomosis of a radial-forearm-free-flap in a clinical setting/in vivo. The system positioning was possible entirely hands-free using head movements. Camera control was intuitive; visualization of the operation site was adequate and independent from head or body position. Besides technical instructions of the providing company, there was no special surgical training of the surgeons or involved staff upfront performing the procedures necessary. An ergonomic assessment questionnaire showed a favorable ergonomic position in comparison to surgery with a microscope. The outcome of the operated patient was good. There were no intra- or postoperative complications. The exoscope facilitates a change of head and body position without losing focus of the operation site and an ergonomic working position. Repeated applications have to clarify if the system benefits in clinical routine.

Ex vivo torsional properties of a 2.5 mm veterinary interlocking nail system in canine femurs

2017 ◽  
Vol 30 (02) ◽  
pp. 118-124 ◽  
Author(s):  
Aline Macedo ◽  
John Runciman ◽  
Tom Gibson ◽  
Bruno Minto ◽  
Noel Moens
Keyword(s):  
Ex Vivo ◽  
Angular Displacement ◽  
Locking Mechanism ◽  
Significant Difference ◽  
Transverse Osteotomy ◽  
Group 3 ◽  
Low Stiffness ◽  
Group 2 ◽  
Torsional Properties ◽  
Group 1

SummaryObjective: To evaluate the torsional properties of the Targon® Vet Nail System (TVS) in small canine femurs and to compare these properties to those of the 2.4 mm LC-DCP® plates.Methods: Thirty-six cadaveric femurs were allocated to three groups (n = 12). In all bones, points just distal to the lesser trochanter and just proximal to the fabellae were marked and a midshaft transverse osteotomy was performed. Group 1: bones were fixed with the 2.5 mm TVS with the bolts applied at the pre-identified marks. Group 2: A TVS system with 25% shorter inter-bolt distance was used. Group 3: A 7-hole 2.4 mm LCDCP® plates were applied. All constructs were tested non-destructively for 10 cycles, followed by an acute torsion to failure.Results: Torque at yield was 0.806 ± 0.183 and 0.805 ± 0.093 Nm for groups 1 and 2 and 1.737 ± 0.461 Nm for group 3. Stiffness was 0.05 ± 0.01, 0.05 ± 0.007, and 0.14 ± 0.015 Nm/° for groups 1 to 3 respectively. Maximal angular displacement under cyclic loading was 16.6° ± 2.5°, 15.6° ± 2.1°, and 7.8° ± 1.06° respectively. There was no significant difference for any of the parameters between groups 1 and 2. Both torque at yield and stiffness were significantly greater between group 3 and groups 1 and 2.Clinical significance: The TVS had approximately half the torsional strength and approximately 1/3 of the stiffness of the 2.4 mm bone plate. Slippage of the locking mechanism was probably the cause of the early failure. The system should be considered as a low-strength and low-stiffness system when compared to bone plates.

scholarly journals Stretch increases alveolar type 1 cell number in fetal lungs through ROCK-Yap/Taz pathway

2021 ◽  
Author(s):  
Tram Mai Nguyen ◽  
Johannes van der Merwe ◽  
Linda Elowsson Rendin ◽  
Anna-Karin Larsson-Callerfelt ◽  
Jan Deprest ◽  
...  
Keyword(s):  
Lung Development ◽  
Molecular Mechanisms ◽  
Ex Vivo ◽  
Fluid Pressure ◽  
Fetal Lung ◽  
In Vivo Model ◽  
Alveolar Type ◽  
Ex Vivo Model

Accurate fluid pressure in the fetal lung is critical for its development, especially at the beginning of the saccular stage when alveolar epithelial type 1 (AT1) and type 2 (AT2) cells differentiate from the epithelial progenitors. Despite our growing understanding of the role of physical forces in lung development, the molecular mechanisms that regulate the transduction of mechanical stretch to alveolar differentiation remain elusive. To simulate lung distension, we optimized both an ex vivo model with precision cut lung slices and an in vivo model of fetal tracheal occlusion. Increased mechanical tension showed to improve alveolar maturation and differentiation towards AT1. By manipulating ROCK pathway, we demonstrate that stretch-induced Yap/Taz activation promotes alveolar differentiation towards AT1 phenotype via ROCK activity. Our findings show that balanced ROCK-Yap/Taz signaling is essential to regulate AT1 differentiation in response to mechanical stretching of the fetal lung, which might be helpful in improving lung development and regeneration.

scholarly journals Ex vivo Induction of Apoptotic Mesenchymal Stem Cell by High Hydrostatic Pressure

2020 ◽  
Author(s):  
Tien Minh Le ◽  
Naoki Morimoto ◽  
Nhung Thi My Ly ◽  
Toshihito Mitsui ◽  
Sharon Claudia Notodihardjo ◽  
...  
Keyword(s):  
Hydrostatic Pressure ◽  
Stromal Cells ◽  
High Hydrostatic Pressure ◽  
Tissue Repair ◽  
Ex Vivo ◽  
Morphological Changes ◽  
Fluid Pressure ◽  
Physical Technique ◽  
Transmission Electron ◽  
The Impact

Abstract Among promising solutions for tissue repair and wound healing, mesenchymal stem (or stromal) cells (MSCs) have been a focus of attention and have become the most clinically studied experimental cell therapy. Recent studies reported the importance of apoptosis in MSC-mediated immunomodulation, in which apoptotic MSCs (apoMSCs) were shown to be superior to living MSCs. Nowadays, high hydrostatic pressure (HHP), a physical technique that uses only fluid pressure, has been developed and applied in various bioscience fields, including biotechnology, biomaterials, and regenerative medicine, as its safe and simply operation. In the current study, we investigated the impact of HHP treatment on human bone marrow-MSC survival and proliferation. Based on the detection of executioner caspase activation, phosphatidylserine exposure, DNA fragmentation (TUNEL) and irrefutable ultrastructural morphological changes on transmission electron microscopy (TEM), our data revealed that HHP treatment induced complete apoptosis in MSCs. Notably, this technique might provide manipulated products for use in cell-based therapies as manufacturing capability expands. We hope that our findings will contribute to the improvement of MSCs or EVs in translational research development.

scholarly journals Stretchable organic optoelectronic sensorimotor synapse

2018 ◽  
Vol 4 (11) ◽  
pp. eaat7387 ◽  
Author(s):  
Yeongjun Lee ◽  
Jin Young Oh ◽  
Wentao Xu ◽  
Onnuri Kim ◽  
Taeho Roy Kim ◽  
...  
Keyword(s):  
Artificial Muscle ◽  
Sensory Receptor ◽  
Optical Wireless ◽  
Optical Signals ◽  
Promising Strategy ◽  
Core Technology ◽  
Self Powered ◽  
Organic Optoelectronic ◽  
Soft Electronics ◽  
Electronic Synapse

Emulation of human sensory and motor functions becomes a core technology in bioinspired electronics for next-generation electronic prosthetics and neurologically inspired robotics. An electronic synapse functionalized with an artificial sensory receptor and an artificial motor unit can be a fundamental element of bioinspired soft electronics. Here, we report an organic optoelectronic sensorimotor synapse that uses an organic optoelectronic synapse and a neuromuscular system based on a stretchable organic nanowire synaptic transistor (s-ONWST). The voltage pulses of a self-powered photodetector triggered by optical signals drive the s-ONWST, and resultant informative synaptic outputs are used not only for optical wireless communication of human-machine interfaces but also for light-interactive actuation of an artificial muscle actuator in the same way that a biological muscle fiber contracts. Our organic optoelectronic sensorimotor synapse suggests a promising strategy toward developing bioinspired soft electronics, neurologically inspired robotics, and electronic prostheses.

scholarly journals Application of a Novel Film Sealant Technology for Penetrating Corneal Wounds: An Ex-Vivo Study

2020 ◽  
Vol 10 (9) ◽  
pp. 3193
Author(s):  
Jackie Tan ◽  
Leslie John Ray Foster ◽  
Stephanie Louise Watson
Keyword(s):  
Ex Vivo ◽  
Fluid Pressure ◽  
Burst Pressure ◽  
Cyanoacrylate Glue ◽  
Film Adhesive ◽  
Testing Chamber ◽  
Wound Leakage ◽  
Ex Vivo Study ◽  
Corneoscleral Rim ◽  
Corneal Wounds

Aim: To compare the burst pressures of corneal wounds closed with a laser-activated, chitosan-based thin film adhesive against self-seal, sutures and cyanoacrylate. Methods: 2, 4 or 6 mm penetrating corneal wounds were created on 100 freshly enucleated bovine eyes. The wounds were closed using a laser-activated chitosan adhesive (n = 30), self-sealed (control) (n = 30), sutures (n = 20) or cyanoacrylate glue (Histoacryl®) (n = 20). The corneoscleral rim was dissected and mounted onto a custom burst pressure testing chamber. Water was pumped into the chamber at 9ml/hr. The fluid pressure prior to wound leakage was recorded as the ‘burst pressure’. Results: The burst pressure for the 2, 4 and 6 mm wounds were 239.2 mmHg (SD = ±102.4), 181.7 mmHg (SD = ±72.8) and 77.4 mmHg (SD = ±37.4) (p < 0.00001), respectively, for chitosan adhesive. Burst pressure was 36.4 mmHg (SD = ±14.7), 4.8 mmHg (SD = ±4.9) and 2.7 mmHg (SD = ±1.3) (p < 0.00001), respectively, for the self-sealed group. For 4 and 6mm wounds, burst pressures with sutures were 33.0 mmHg (SD = ±19) and 23.5 mmHg (SD = ±17.4) (p = 0.0087), respectively. For cyanoacrylate, burst pressures for 2 and 4 mm wounds were 698 mmHg (SD = ±240.3) and 494.3 mmHg (SD = ±324.6) (p = 0.020087), respectively. Conclusion: This laser-activated chitosan-based adhesive sealed bovine corneal wounds up to 6 mm in length. Burst pressure was higher for the adhesive than sutured or self-sealed wounds, but lower than for cyanoacrylate.

Protection against high intravascular pressure in giraffe legs

2013 ◽  
Vol 305 (9) ◽  
pp. R1021-R1030 ◽  
Author(s):  
Karin K. Petersen ◽  
Arne Hørlyck ◽  
Kristine H. Østergaard ◽  
Joergen Andresen ◽  
Torbjoern Broegger ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Sympathetic Innervation ◽  
Fluid Pressure ◽  
Segment Length ◽  
Internal Diameter ◽  
Resistance Arteries ◽  
Structural Adaptation ◽  
Small Arteries ◽  
Viscous Pressure ◽  
Intravascular Pressure

The high blood pressure in giraffe leg arteries renders giraffes vulnerable to edema. We investigated in 11 giraffes whether large and small arteries in the legs and the tight fascia protect leg capillaries. Ultrasound imaging of foreleg arteries in anesthetized giraffes and ex vivo examination revealed abrupt thickening of the arterial wall and a reduction of its internal diameter just below the elbow. At and distal to this narrowing, the artery constricted spontaneously and in response to norepinephrine and intravascular pressure recordings revealed a dynamic, viscous pressure drop along the artery. Histology of the isolated median artery confirmed dense sympathetic innervation at the narrowing. Structure and contractility of small arteries from muscular beds in the leg and neck were compared. The arteries from the legs demonstrated an increased media thickness-to-lumen diameter ratio, increased media volume, and increased numbers of smooth muscle cells per segment length and furthermore, they contracted more strongly than arteries from the neck (500 ± 49 vs. 318 ± 43 mmHg; n = 6 legs and neck, respectively). Finally, the transient increase in interstitial fluid pressure following injection of saline was 5.5 ± 1.7 times larger ( n = 8) in the leg than in the neck. We conclude that 1) tissue compliance in the legs is low; 2) large arteries of the legs function as resistance arteries; and 3) structural adaptation of small muscle arteries allows them to develop an extraordinary tension. All three findings can contribute to protection of the capillaries in giraffe legs from a high arterial pressure.

scholarly journals Integrated Quad-Scanner Strategy-Based Optical Coherence Tomography for the Whole-Directional Volumetric Imaging of a Sample

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1305
Author(s):  
Sm Abu Saleah ◽  
Daewoon Seong ◽  
Sangyeob Han ◽  
Ruchire Eranga Wijesinghe ◽  
Naresh Kumar Ravichandran ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Ex Vivo ◽  
3D Visualization ◽  
Three Dimensional ◽  
Physical Structure ◽  
Mouse Heart ◽  
Optical Coherence ◽  
Volume Data ◽  
Data Set ◽  
Inspection Method

Whole-directional scanning methodology is required to observe distinctive features of an entire physical structure with a three dimensional (3D) visualization. However, the implementation of whole-directional scanning is challenging for conventional optical coherence tomography (OCT), which scans a limited portion of the sample by utilizing unidirectional and bidirectional scanning methods. Therefore, in this paper an integrated quad-scanner (QS) strategy-based OCT method was implemented to obtain the whole-directional volumetry of a sample by employing four scanning arms installed around the sample. The simultaneous and sequential image acquisition capabilities are the conceptual key points of the proposed QS-OCT method, and were implemented using four precisely aligned scanning arms and applied in a complementary way according to the experimental criteria. To assess the feasibility of obtaining whole-directional morphological structures, a roll of Scotch tape, an ex vivo mouse heart, and kidney specimens were imaged and independently obtained tissue images at different directions were delicately merged to compose the 3D volume data set. The results revealed the potential merits of QS-OCT-based whole-directional imaging, which can be a favorable inspection method for various discoveries that require the dynamic coordinates of the whole physical structure.

Preparation And elemental analysis of ancient fibers

1987 ◽  
Vol 45 ◽  
pp. 410-411
Author(s):  
Allen Angel ◽  
Kathryn A. Jakes
Keyword(s):  
Cross Sections ◽  
Physical Structure ◽  
Energy Dispersive ◽  
Archaeological Sites ◽  
X Ray ◽  
Long Term Storage ◽  
Backscattered Electron ◽  
Electron Imaging

Fabrics recovered from archaeological sites often are so badly degraded that fiber identification based on physical morphology is difficult. Although diagenetic changes may be viewed as destructive to factors necessary for the discernment of fiber information, changes occurring during any stage of a fiber's lifetime leave a record within the fiber's chemical and physical structure. These alterations may offer valuable clues to understanding the conditions of the fiber's growth, fiber preparation and fabric processing technology and conditions of burial or long term storage (1).Energy dispersive spectrometry has been reported to be suitable for determination of mordant treatment on historic fibers (2,3) and has been used to characterize metal wrapping of combination yarns (4,5). In this study, a technique is developed which provides fractured cross sections of fibers for x-ray analysis and elemental mapping. In addition, backscattered electron imaging (BSI) and energy dispersive x-ray microanalysis (EDS) are utilized to correlate elements to their distribution in fibers.

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