Nonlinear Adaptive Optimal Controller Design for Anti-Angiogenic Tumor Treatment.

Angiogenesis is an important process in tumor growth as it represents the regime when the tumor recruits blood vessels from the surrounding tissue to support further tumor growth. Anti-angiogenic treatments aim to shrink the tumor by interrupting the vascularization of the tumor; however, the anti-angiogenic agents are costly and the tumor response to these agents is nonlinear. Simple dosing schemes, e.

Long Thoracic Nerve Injury Caused by Overhead Weight Lifting Leading to Scapular Dyskinesis and Medial Scapular Winging.

Scapular winging represents a rare phenomenon that most commonly results from nerve damage to either the long thoracic nerve, spinal accessory nerve, or, less commonly, the dorsal scapular nerve. This injury results in an abnormal scapulohumeral interaction during kinetic motion known as scapular dyskinesis. In this case report, the patient presented with scapular dyskinesis and medial scapular winging caused by overhead weight-lifting exercises, and a long thoracic nerve injury was diagnosed.

Learning to perceive haptic distance-to-break in the presence of friction.

Two experiments employed attunement and calibration training to investigate whether observers are able to identify material break points in compliant materials through haptic force application. The task required participants to attune to a recently identified haptic invariant, distance-to-break (DTB), rather than haptic stimulation not related to the invariant, including friction. In the first experiment participants probed simulated force-displacement relationships (materials) under 3 levels of friction with the aim of pushing as far as possible into the materials without breaking them.

Design and optimization of a novel bio-loom to weave melt-spun absorbable polymers for bone tissue engineering.

Bone graft procedures are currently among the most common surgical procedures performed worldwide, but due to high risk of complication and lack of viable donor tissue, there exists a need to develop alternatives for bone defect healing. Tissue engineering, for example, combining biocompatible scaffolds with mesenchymal stem cells to achieve new bone growth, is a possible solution. Recent work has highlighted the potential for woven polymer meshes to serve as bone tissue engineering scaffolds; since, scaffolds can be iteratively designed by adjusting weave settings, material types, and mesh parameters.

A Novel Platform for Assessment of Surgical Suturing Skill: Preliminary Results.

In this work, we describe a novel platform for quantifying surgical suturing skill. Forces and user movements are recorded using sensors during suturing maneuvers performed on a suture patch. Preliminary results from a pilot experiment suggest that force data could be used for objective assessment of suturing skill.

Investigating haptic distance-to-break using linear and nonlinear materials in a simulated minimally invasive surgery task.

Accurate detection of mediated haptic information in minimally invasive surgery (MIS) is critical for applying appropriate force magnitudes onto soft tissue with the aim of minimising tissue trauma. Force perception in MIS is a dynamic process, with surgeons' administration of force into tissue revealing information about the remote surgical site which further informs the surgeons' haptic interactions. The relationship between applied force and material deformation rate provides biomechanical information specifying the deformation distance remaining until a tissue will fail: which is termed distance-to-break (DTB).

A perspective on the role and utility of haptic feedback in laparoscopic skills training.

Laparoscopic surgery is a minimally invasive surgical technique with significant potential benefits to the patient, including shorter recovery time, less scarring, and decreased costs. There is a growing need to teach surgical trainees this emerging surgical technique. Simulators, ranging from simple "box" trainers to complex virtual reality (VR) trainers, have emerged as the most promising method for teaching basic laparoscopic surgical skills.

A real-time adaptive oxygen transfer rate estimator for metabolism tracking in Escherichia coli cultures.

Oxygen transfer rate (OTR) is the most significant signal for aerobic bioprocess control, since most microbic metabolic activity relies on oxygen consumption. However, accurate estimation of OTR is challenging due to the difficulty of determining uncertain oxygen transfer parameters and system dynamics. This paper presents an adaptive estimator, which incorporates exhaust gas, stir speed and dissolved oxygen measurements, to predict the real-time OTR.

A CMI (cell metabolic indicator)-based controller for achieving high growth rate Escherichia coli cultures.

A large fraction of biopharmaceuticals are produced in Escherichia coli, where each new product and strain currently requires a high degree of growth characterization in benchtop and industrial bioreactors to achieve economical production protocols. The capability to use a standard set of sensors to characterize a system quickly without the need to conduct numerous experiments to determine stable growth rate for the strain would significantly decrease development time. This paper presents a cell metabolic indicator (CMI) which provides better insight into the E.

Simulator-based assessment of haptic surgical skill: a comparative study.

The aim of this study was to examine if the forces applied by users of a haptic simulator could be used to distinguish expert surgeons from novices. Seven surgeons with significant operating room expertise and 9 novices with no surgical experience participated in this study. The experimental task comprised exploring 4 virtual materials with the haptic device and learning the precise forces required to compress the materials to various depths.

Endovascular seldinger needle placement: a simulator for examining haptic skills.

In this work, we develop an affordable haptic simulator for examining haptic skills required for endovascular Seldinger needle placement.

A haptic simulator to increase laparoscopic force application sensitivity.

Laparoscopic surgery demands perceptual-motor skills that are fundamentally different from open surgery, and laparoscopists must be adept at perceiving tissue interaction at the surgical site and then applying precise amounts of forces through instruments without damaging tissues. A haptic simulator that emulates multiple salient laparoscopic tasks and renders differing degrees of forces was created. Two of the haptic skills tasks were evaluated in two studies to determine their ability to distinguish and then train laparoscopic force application sensitivity.

Salient haptic skills trainer: initial validation of a novel simulator for training force-based laparoscopic surgical skills.

Background: There is an increasing need for efficient training simulators to teach advanced laparoscopic skills beyond those imparted by a box trainer. In particular, force-based or haptic skills must be addressed in simulators, especially because a large percentage of surgical errors are caused by the over-application of force. In this work, the efficacy of a novel, salient haptic skills simulator is tested as a training tool for force-based laparoscopic skills.

Objective differentiation of force-based laparoscopic skills using a novel haptic simulator.

Background: There is a growing need for effective surgical simulators to train the novice resident with a core skill set that can be later used in advanced operating room training. The most common simulator-based laparoscopic skills curriculum, the Fundamentals of Laparoscopic Skills (FLS), has been demonstrated to effectively teach basic surgical skills; however, a key deficiency in current surgical simulators is lack of validated training for force-based or haptic skills. In this study, a novel haptic simulator was examined for construct validity by determining its ability to differentiate between the force skills of surgeons and novices.

A quantitative metric for pattern fidelity of bioprinted cocultures.

This article describes a quantitative metric for coculture pattern fidelity and its use in the assessment of bioprinting systems. Increasingly, bioprinting is used to create in vitro cell and tissue models for the purpose of studying cell behavior and cell-cell interaction. To create meaningful models, a bioprinting system must be able to place cells in biologically relevant patterns with sufficient fidelity.

Haptic tasks for physical laparoscopic ("Box") trainers to differentiate surgeon skill.

In this work, we present four tasks, primarily testing haptic laparoscopic skill that can be simulated in a conventional box trainer. Results from examining expert surgeon and novice performance is presented as evidence that these tasks can be used for training haptic skills for laparoscopy in a box trainer.

Assessing surgeon and novice force skill on a haptic stiffness simulator for laparoscopic surgery.

Though several simulators and training methods are available for basic laparoscopic skills, few have addressed force-based skills. In this work, we discuss a haptic simulator that renders virtual materials of different stiffness profiles to be used for haptic skills differentiation. A force-based task was designed on the simulator and the performance of surgeons and novices was analyzed.

Characterizing the effects of cell settling on bioprinter output.

The time variation in bioprinter output, i.e. the number of cells per printed drop, was studied over the length of a typical printing experiment.

Cell settling effects on a thermal inkjet bioprinter.

This paper seeks to quantify cell settling in the print media reservoir of a bioprinter in order to determine its effect on consistent cell delivery per printed drop. The bioprinter studied here is based on the thermal inkjet HP26A cartridge, but any system that dispenses controlled volumes of fluid may be affected similarly. A simple model based on Stokes' law suggests that the cell concentration in the bottom of the reservoir should increase linearly up to some maximum and that the cell concentration in the printed drops should follow this trend.

Role of haptic feedback in a basic laparoscopic task requiring hand-eye coordination.

This work discusses the role and importance of haptic feedback and simulator training for simple laparoscopic tasks akin to the FLS peg-transfer task. Results from a study designed to examine haptics for this purpose are discussed.

Perceptual metrics: towards better methods for assessing realism in laparoscopic simulators.

This work proposes a novel class of metrics for assessing haptic realism in laparoscopic surgical simulators. Results from a proposed perceptual metric are presented and discussed.

Post-bioprinting processing methods to improve cell viability and pattern fidelity in heterogeneous tissue test systems.

Bioprinted tissue test systems show promise as a powerful tool for studying cell-cell interaction in heterogeneous, tissue-like co-culture. Several challenges were encountered while attempting to consistently fabricate samples with high viability and pattern fidelity. This paper evaluates four methods for processing samples after bioprinting but prior to adding media for incubation.

Building off-the-shelf tissue-engineered composites.

Rapid advances in technology have created the realistic possibility of personalized medicine. In 2000, Time magazine listed tissue engineering as one of the 'hottest 10 career choices'. However, in the past decade, only a handful of tissue-engineered products were translated to the clinical market and none were financially viable.

Design and implementation of a two-dimensional inkjet bioprinter.

Tissue engineering has the potential to improve the current methods for replacing organs and tissues and for investigating cellular process within the scope of a tissue test system. Bioprinting technology can aid in the difficult task of arranging live mammalian cells and biomaterials in viable structures for tissue engineering purposes. This paper describes a system, based on HP26 series print cartridge technology, capable of precisely depositing multiple cell types in precise patterns.

EDTA enhances high-throughput two-dimensional bioprinting by inhibiting salt scaling and cell aggregation at the nozzle surface.

Tissue-engineering strategies may be employed in the development of in vitro breast tissue models for use in testing regimens of drug therapies and vaccines. The physical and chemical interactions that occur among cells and extracellular matrix components can also be elucidated with these models to gain an understanding of the progression of transformed epithelial cells into tumours and the ultimate metastases of tumour cells. The modified inkjet printer may be a useful tool for creating three-dimensional (3D) in vitro models, because it offers an inexpensive and high-throughput solution to microfabrication, and because the printer can be easily manipulated to produce varying tissue attributes.