Michael Whitt

Surface engineered surgical tools and medical devices

Surface engineered surgical tools and medical devices / , Surface engineered surgical tools and medical devices / , کتابخانه دیجیتال جندی شاپور اهواز

The use of portable particle measurement devices to characterise airborne particles generated in various settings

The accurate measurement of ultrafine and submicron sized airborne particles is a challenging task. Since several studies have linked exposures to airborne ultrafine particles to elevated human health risks, the need to assess the concentrations of particles in the workplace that are below one micron in diameter is imperative. Several techniques for directly monitoring micro and nanoparticles are available and others are being tested for their merit. Condensation Nuclei Counters (CNCs), portable condensation particle counters, differential mobility analysers, electron microscopy and other novel approaches to measuring micro and nanoparticles have been employed in investigations. The purpose of this paper is to elucidate the results from three studies involving the measurement of airborne particles with a laser particle counter and condensation nuclei counter. The three environments include: a gambling casino, a Shielded Metal Arc Welding (SMAW) operation and a general manufacturing facility with welding, cutting and grinding operations being performed.

Cardiovascular metrics and transepidermal water loss in a high heat risk environment

Heat stress is currently primarily classified by environmental factors and not physiological factors. It is already known that certain cardiovascular metrics such as heart rate, stroke volume, blood pressure and vascular compliance undergo changes as the body traverses the different classifications of heat stress from heat oedema to heat stroke. However, there is no specific metric that provides a consistent indication for the onset of heat stroke. Twenty four subjects were observed over a 30-minute time frame performing exercise where WBGT equalled 27.5°C to determine if gender, activity-level or age had a significant effect on transepidermal water loss (TEWL) rate in addition to the relationship that the cardiovascular metrics had with TEWL rate. It was determined that heart rate, elapsed time exercising in the high temperature/humidity environment and age of subject all had significant effects on TEWL rate at a 95% confidence. Preliminary results demonstrate the possible existence of a relationship between sympathetic baroreflex sensitivity, cardiovagal baroreflex sensitivity and TEWL.

Cardiovascular Interventional and Implantable Devices

Cardiovascular interventional and implantable devices must be safe and efficacious, as well as biocompatible. Surface treatment is of importance to the design and function of these devices. Lubricity, wear resistance, thrombogenicity, inflammation, and infections can all be affected significantly by surface treatments. The surfaces of cardiovascular interventional and implantable devices can either be modified with active or passive coating. Devices with active coating such as drug eluting stents (DES) deliver therapeutic agents that can enhance the mechanical function and modulate long-term vascular responses. In some implantable devices such as vascular grafts, endothelial cell growth is desirable. This is achievable with the addition of a coating or a modification to the surface properties of the device. This chapter reviews some of the most commonly used cardiovascular interventional and implantable devices with an overview of the role that surface treatments have in their functionality and safety.

Environmental and Occupational Health Issues with Nanoparticles

There are various environmental as well as worker health and safety issues involved with manufacturing or fabrication efforts that result in the creation of particles in the nanoparticle size range. While the research in this area is in the relatively early stages, several studies have been conducted over the last decade or so that focus on the environmental and human exposure issues surrounding the anthropogenic generation of airborne ultrafine or nanometre-range particles. The purpose of this chapter is to elucidate the current state of the literature regarding nanoparticles in the workplace and environment as well as to provide the latest characterization techniques used to conduct airborne nanoscale particle measurement.

Chapter 9 – Environmental and Occupational Health Issues with Nanoparticles

There are various environmental as well as worker health and safety issues involved with manufacturing or fabrication efforts that result in the creation of particles in the nanoparticle size range. While the research in this area is in the relatively early stages, several studies have been conducted over the last decade or so that focus on the environmental and human exposure issues surrounding the anthropogenic generation of airborne ultrafine or nanometre-range particles. The purpose of this chapter is to elucidate the current state of the literature regarding nanoparticles in the workplace and environment as well as to provide the latest characterization techniques used to conduct airborne nanoscale particle measurement.

Chapter 10 – Commercialization of Nanotechnologies: Technology Transfer from University Research Laboratories

The commercialization of nanotechnology from university spin-out companies is viewed as critical for the sustainable development of tertiary-level technologies. This chapter outlines the roles of venture capitalists, Government, academic institutions, and entrepreneurs in providing society with nanotechnology companies that turn science into money. The chapter also explains how the technology is transferred in the marketplace through patents, trade secrets, and copyrights, and allows the academic entrepreneur to understand the role of consumers and markets.

Sympathetic and cardiovagal baroreflex sensitivity as related to heat stroke

Heat stroke diagnosis takes place when core temperature exceeds 40.5°C. Many risk factors, environmental and non-environmental, are associated with increased occurrence of heat stroke. Early diagnosis of a heat related illness is believed to be important in the effective reduction of heat stress mortality and morbidity rates. Sympathetic and cardiovagal baroreflex sensitivity could provide metrics to aid in the early diagnosis. Data analysis took place using previous data from an experiment where 24 subjects performed 30 minutes of cardiovascular exercise in a chamber with WBGT equal to 27.5°C. The primary experimental objective was observation of a relationship between transepidermal water loss and cardiovascular metrics. Thus, the design of experiments limited the amount of valuable information able to be extracted pertaining to sympathetic and cardiovagal baroreflex sensitivity. However, a test of means demonstrated that diastolic pressure and heart rate underwent significant changes with time in the hot and humid environment.