Luke Seed

A survey on fall detection: Principles and approaches

Fall detection is a major challenge in the public health care domain, especially for the elderly, and reliable surveillance is a necessity to mitigate the effects of falls. The technology and products related to fall detection have always been in high demand within the security and the health-care industries. An effective fall detection system is required to provide urgent support and to significantly reduce the medical care costs associated with falls. In this paper, we give a comprehensive survey of different systems for fall detection and their underlying algorithms. Fall detection approaches are divided into three main categories: wearable device based, ambience device based and vision based. These approaches are summarised and compared with each other and a conclusion is derived with some discussions on possible future work.

Design and evaluation of an epoxy three-dimensional multichip module

A low-cost, three-dimensional multichip module (MCM) technology provides greatly improved system density and reduced mass over planar packaging technologies. The technology offers a high degree of testability that negates the need for known good die (KGD) procurement. Testing is achieved with very low cost overheads and with no increase in the volume of the module. The technology allows complete, heterogeneous systems to be packaged and interconnected in a single, ultra-dense module. The electrical characteristics of the technology are comparable to standard chip packages. However, the parasitics due to package-to-package interconnects are eliminated. This removes the dominant cause of parasitics, dramatically improving the electrical characteristics. A programmable integrated camera and image processing system has been developed which incorporates a grayscale camera, analog-to-digital conversion, four programmable processors and memory. Utilizing the three-dimensional multichip module technology, the system, which consists of nine chips and 36 discrete components, has an overall volume of 4.77 ml. This is approximately six times more dense than an advanced PCB implementation. The system forms the first stage in the design and manufacture of a portable video communications device. For such applications, low system volume and mass are key attributes. The system demonstrates the potential of the packaging technique for the integration of complete mixed signal systems incorporating sensors and processing. Further developments to the technology will provide increased module density, improved routing capacity, and electrical performance.

Single Ended Pass-Transistor Logic

SPL (Single-rail Pass-transistor Logic) is one of the most promising logic styles for low power circuits. This paper examines some key issues in the implementation of SPL: swing restoration, optimum number of pass-transistor stages between buffers and SPL circuits with two supply voltages. Simulation results based on netlists extracted from layout are presented to compare SPL, CPL and standard CMOS.

Utilizing a low cost 3D packaging technology for consumer applications

This paper demonstrates how a low cost three-dimensional packaging (multichip module-vertical) technology can be utilized to implement systems for consumer applications. In any application where system cost, volume and mass are important, this packaging technique can be advantageous, particularly in the rapidly growing portable electronics industry. To illustrate this we present a general-purpose, low-cost camera and image processing system in the new packaging technology. This can be used in multimedia, surveillance and smart vision applications.

Non‐planar interconnect

Purpose – This paper describes a method for patterning fine line interconnections over non‐planar surfaces and introduces the idea of using holographic masks for more challenging geometries.Design/methodology/approach – A photolithographic method for achieving grossly non‐planar interconnects is described. The patterning of electrical interconnections onto the piezo‐electric actuators of an ink‐jet print head is used as an example. Uniform coverage of the substrate is achieved using an electro‐depositable photoresist. The required pattern is transferred via a custom‐designed chrome‐on‐glass mask using a standard mask aligner.Findings – Large arrays of 100 μm‐pitch electrical interconnections were successfully deposited onto 500 μm‐high high piezo‐electric actuators. It was necessary to modify the shapes of the line segments on the mask in order to compensate for diffractive line broadening. For more extreme 3D geometries it becomes necessary to consider the use of holographic masks.Originality/value – Pri...

3D electrically small dome antenna

Modifications to a 3D electrically small antenna (ESA) are presented for dual-band and wide-band performance respectively. The design is based on a recently published dome antenna with conformal meanderlines and fed by a microstrip network. By modifying both the meanderlines and microstrips, the antenna is shown to have a voltage standing wave ratio (VSWR) below 3 for the primary 2.45 GHz band and a 3.5 GHz band. By altering this new feed structure, the antenna can be shown to increase the bandwidth at the 2.45 GHz band by nearly 100 MHz for VSWR equals 3. Rapid prototyping of two antenna designs was carried out using 3D additive printed substrates metalized by Damascening conductive silver ink; the manufactured antennas are scaled up to four times the size of simulations, and offer quick validations of the simulation claims.

Photolithography on three dimensional substrates

Photolithography is the primary technique for patterning planar substrates. However, some higher-density packaging solutions require tine features to be patterned onto grossly non-planar substrates, for example, in mechanical, optical and fluidic microsystems and packaging schemes. Standard photolithography cannot be used in these cases because the inevitable gap between the (planar) mask and (non-planar) substrate causes diffractive line broadening and loss of resolution. We address this issue by realising the mask as a computer generated hologram (CGH), which can then be illuminated to generate an image in space corresponding to the required non-planar profile. The CGHs are derived from analytical expressions and encode both amplitude and phase information. We illustrate the performance with a 100 mum line exposed onto a substrate in the form of a plane/slope/plane, in which the change in depth is 40mm. Enhancements to the line shape are discussed that make the technique more robust to manufacturing process variations. The fact that features in the range 10-100 mum can be imaged at large distance whilst coping with significant changes of depth indicates that the technique shows great potential in the microelectronics packaging industry

Efficiency measurements of additive manufactured electrically small antennas

Additive manufactured prototypes based on a novel inverted-F antenna design are presented and measured results discussed. Radiation efficiency is computed with the aid of a Wheeler cap box; the resulting ratio of the antennas quality factor to the lower limit described by Chu is shown to be 1.9 for a spherical variant. Measured and simulated S-parameter results show good agreement, with some evident discrepancies - these are explained by potential unknown changes to the powdered materials during the printing processes, and the rough surface finish of the metallization on the antennas.

3D printed electrically small planar inverted-F antenna: Efficiency improvement through voluminous expansion

An electrically small inverted-F antenna is designed, as a planar 2D antenna, and subsequently extended to a 3D profile to study the effects of voluminous expansion on the antennas gain and efficiency. 3D prototypes will be fabricated using two different additive manufacturing methods to compare and contrast the strengths of each, and benchmarked against 2D additive printed and standard lithographic fabricated samples. Simulation results show an improvement in the antenna gain from -14.0 dB to -5.6 dB from planar to 3D.

Compact Electrically Small Antenna for Smart Watch Application

With the rise in popularity of wearable gadgets and the birth of the internet of things, new challenges are presented to antenna engineers with respect to the design space available. To this end, a compact, electrically small inverted-F antenna is designed for use in a smart watch. The design is carried out in-vitro, using numerical modelling techniques, and is benchmarked against a traditional planar inverted-F antenna from literature. The novel design presented reduces the overall size of the antenna by a factor of 3.5. It has a gain of -12.7 dB, and a half-power fractional bandwidth of 32%, and is shown to operate well within the specific absorption rate regulatory limits when operated at 25 mW.