Enabling multi-point haptic grasping in virtual environments

Haptic interaction has received increasing research interest in recent years. Currently, most commercially available haptic devices provide the user with a single point of interaction. Multi-point haptic devices present a logical progression in device design and enable the operator to experience a far wider range of haptic interactions, particularly the ability to grasp via multiple fingers. This is highly desirable for various haptically enabled applications including virtual training, telesurgery and telemanipulation. This paper presents a gripper attachment which utilises two low-cost commercially available haptic devices to facilitate multi-point haptic grasping. It provides the ability to render forces to the user's fingers independently and using Phantom Omni haptic devices offers several benefits over more complex approaches such as low-cost, reliability, and ease of programming. The workspace of the gripper attachment is considered and in order to haptically render the desired forces to the user's fingers, kinematic analysis is discussed and necessary formulations presented. The integrated multi-point haptic platform is presented and exploration of a virtual environment using CHAI 3D is demonstrated.

Design of a compact microfludic device for controllable cell distribution

A compact microfluidic device with 96 microchambers allocated within four circular units was designed and examined for cell distribution. In each unit, cells were distributed to the surrounding chambers radially from the center. The circular arrangement of the chambers makes the design simple and compact. A controllable and quantitative cell distribution is achievable in this device. This design is significant to the microfluidic applications where controllable distribution of cells in multipule microchambers is demanded.

Design and analysis of an antenna for wireless energy harvesting in head-mountable DBS device

This paper presents design and simulation of a circular meander dipole antenna at the industrial, scientific, and medical band of 915 MHz for energy scavenging in a passive head-mountable deep brain stimulation device. The interaction of the proposed antenna with a rat body is modeled and discussed. In the antenna, the radiating layer is meandered, and a FR-4 substrate is used to limit the radius and height of the antenna to 14 mm and 1.60 mm, respectively. The resonance frequency of the designed antenna is 915 MHz and the bandwidth of 15 MHz at a return loss of -10 dB in free space. To model the interaction of the antenna with a rat body, two aspects including functional and biological are considered. The functional aspect includes input impedance, resonance frequency, gain pattern, radiation efficiency of the antenna, and the biological aspect involves electric field distribution, and SAR value. A complete rat model is used in the finite difference time domain based EM simulation software XFdtd. The simulated results demonstrate that the specific absorption rate distributions occur within the skull in the rat model, and their values are higher than the standard regulated values for the antenna receiving power of 1W.

Design and analysis of a low actuation voltage electrowetting-on-dielectric device

This paper presents an Electrowetting-on-Dielectric (EWOD) device with optimized insulating layers operated by low actuation voltage. The device consists of an electrode array on a silicon substrate, covered by a dielectric layer and a hydrophobic layer. To characterize the performance of the device, simulations are performed for the dielectric layer of Sio₂ and the hydrophobic layer of Sio₂, Su-8 and Parylene C at different voltages. The volume finite difference approach of the Coventorware software was used to carry out the simulations. Two different molar of di-ionized water droplet were considered in the simulations. It was observed that the device having the Sio₂ dielectric layer and the Parylene C hydrophobic layer moved the 1M KCL (potassium chloride) droplet at the actuation voltage of 25V.

Design and properties of a new hybrid stent-graft device

This PhD work explored a novel bio-inspired approach for designing artificial blood vessel implants known as stent-grafts. The design was inspired from body design of a caterpillar. This design concept induced natural flexibility and expandability property in the new stent-graft, which is considered critical in deciding long-term health of treated patients.

Architect as composer: engaging architecture students with music in the design studio

This paper explores the engagement of architectural students with music in a second year design studio, through a Game and two design projects. A ‘Game’, in the context of this research, is a low-risk learning activity derived from the model established in the CUTSD ‘Reflective Making’ project. The Game required students to complete one of three tasks; to compose and record a piece of electronic music; to research the works of a composer within a digital presentation or to design a prototype musical instrument. This was used as a generative device to inform the design of a Music Room: a space for the contemplation and composition of music. A third stage of the project involved the actual construction of 8 Music Rooms, a high-risk, high-reward activity that requires physical resolution of an established relationship between music and architecture.

This paper will focus on the engagement of architecture students with the Game and related design projects. Student perceptions of the project are used to inform an evaluation of the project as an authentic learning experience and as a valuable component of their architectural education.

Low-flow oxygen therapy: selecting the right device

The authors provide and overview of oxygen therapy principles, describing the indications and care requirements of three low flow oxygen therapy devices and providing an algorithm for managing refractory hypoxaemia.

Extending haptic device capability for 3D virtual grasping

This paper presents an investigation into the workspace constraints observed through the use of multiple single point haptic interfaces, which lead to the design of a novel grasping device that improves upon current commercial haptic interfaces. The presented device is desktop based, and has been designed to maximise the haptic workspace while offering the ability to grasp and manipulate virtual objects, which is a function that current commercial interfaces are limited in providing. The performance of the commercial haptic interface in producing sustained effective operation and increased workspace with the attached haptic gripper is evaluated, and the improvement of both has been determined.

A low-cost intelligent gas sensing device for military applications

The field of electronic noses and gas sensing has been developing rapidly since the introduction of the silicon based sensors. There are numerous systems that can detect and indicate the level of a specific gas. We introduce here a system that is low power, small and cheap enough to be used in mobile robotic platforms while still being accurate and reliable enough for confident use. The design is based around a small circuit board mounted in a plastic case with holes to allow the sensors to protrude through the top and allow the natural flow of gas evenly across them. The main control board consists of a microcontroller PCB with surface mount components for low cost and power consumption. The firmware of the device is based on an algorithm that uses an Artificial Neural Network (ANN) which receives input from an array of gas sensors. The various sensors feeding the ANN allow the microcontroller to determine the gas type and quantity. The Testing of the device involves the training of the ANN with a number of different target gases to determine the weightings for the ANN. Accuracy and reliability of the ANN is validated through testing in a specific gas filled environment.

Microprocessor-based insulin delivery device with amperometric glucose sensing

This paper details the design of a closed-loop insulin delivery device, consisting of a glucose sensing circuit, and a basic microprocessor-based syringe pump. The glucose sensing circuit contains the required components to interface with CGMS's glucose sensor assembly, while the syringe pump design uses microprocessor to allow flexible control over the pump driver. Instrumentation developed in this paper provides a ready reference to other researchers on the construction of a closed-loop insulin delivery apparatus with amperometric glucose sensor.

Design and optimization of LNA topologies with image rejection filters

An important problem in designing RFIC in CMOS technology is the parasitic elements of passive and active devices that complicate design calculations. This article presents three LNA topologies including cascode, folded cascade, and differential cascode and then introduces image rejection filters for low-side and high-side injection. Then, a new method for design and optimization of the circuits based on a Pareto-based multiobjective genetic algorithm is proposed. A set of optimum device values and dimensions that best match design specifications are obtained. The optimization method is layout aware, parasitic aware, and simulation based. Circuit simulations are carried out based on TSMC 0.18 um CMOS technology by using Hspice.

A microfluidics device to monitor platelet aggregation dynamics in response to strain rate micro-gradients in flowing blood

This paper reports the development of a platform technology for measuring platelet function and aggregation based on localized strain rate micro-gradients. Recent experimental findings within our laboratories have identified a key role for strain rate micro-gradients in focally triggering initial recruitment and subsequent aggregation of discoid platelets at sites of blood vessel injury. We present the design justification, hydrodynamic characterization and experimental validation of a microfluidic device incorporating contraction–expansion geometries that generate strain rate conditions mimicking the effects of pathological changes in blood vessel geometry. Blood perfusion through this device supports our published findings of both in vivo and in vitro platelet aggregation and confirms a critical requirement for the coupling of blood flow acceleration to downstream deceleration for the initiation and stabilization of platelet aggregation, in the absence of soluble platelet agonists. The microfluidics platform presented will facilitate the detailed analysis of the effects of hemodynamic parameters on the rate and extent of platelet aggregation and will be a useful tool to elucidate the hemodynamic and platelet mechano-transduction mechanisms, underlying this shear-dependent process.

A context-sensitive device to help people with autism cope with anxiety

We describe a smartphone application that helps people with Autism Spectrum Disorder (ASD) cope with anxiety attacks. Our prototype provides a one-touch interface for indicating a panic level. The device's response-to instruct, soothe, and/or contact carers-is sensitive to the user's context, consisting of time, location, ambient noise, and nearby friends. Formative evaluation unearths a critical challenge to building assistive technologies for ASD sufferers: can regimented interfaces foster flexible behaviour? Our observations suggest that a delicate balance of design goals is required for a viable assistive technology.

Design, development, and evaluation of a pinch-grasp haptic interface

Interaction with virtual or teleoperated environments requires contact with objects on a multipoint level. We describe the design of a pinch--grasp hand interface device for use as a grasping mechanism to complement haptic interfaces. To preserve a suitable level of transparency for human--computer interaction, this novel interface is designed for high-resolution contact forces, while centered around a lightweight structure. This functionality renders the device scalable and adaptable to a wide range of haptic interface structures and force level requirements. We present an optimal configuration for a pinch--grasp interface, which produces bidirectional forces to an operator's fingers and a rotational force to the wrist through a cable drive system. The device is characterized for use on a commercial haptic interface through demonstration of sustained peak performance and also workspace utilization. The dynamic performance of the pinch--grasp interface is experimentally determined, and the frequency response is identified to illustrate its contact force resolution.