Device Usability

Each year, a vast sum of money is spent to produce various types of medical devices throughout the world. Their usability has become an important issue, because various studies conducted over the years indicate that poorly designed human-machine interfaces of medical devices significantly increase the risk for the occurrence of human errors [1-4], These errors can directly or indirectly result in patient injury or death. 

This chapter presents various important aspects of medical device usability. 

---

Cumulative trauma disorder presents a significant risk to health care workers and can be minimized by better medical device usability-related design and better work habits reinforced through effective instructions and warning labels [2,16]. 

Over the years, a large number of publications on engineering usability and related areas have appeared [2], Some that can be useful to improve medical device usability—and in turn, patient safety—are as follows ... 

Chapter 10 is devoted to medical device usability. It covers topics such as medical device users and use environments, medical device user interfaces, an approach to develop medical devices effective user interfaces, guidelines to reduce medical device user interface-related errors, guidelines for designing hand-operated devices with respect to cumulative trauma disorder, and useful documents for improving usability of medical devices. Chapter 11 presents three important topics relating to patient safety patient safety organizations, data sources, and mathematical models for performing probabilistic patient safety analysis. 

Orga.nic Colora.nts. The importance of coal-tar colorants cannot be overemphasized. The cosmetic industry, in cooperation with the FDA, has spent a great deal of time and money in efforts to estabUsh the safety of these dyes (see Colorants for food, drugs, cosmetics, and medical devices). Contamination, especially by heavy metals, and other impurities arising from the synthesis of permitted dyes are stricdy controlled. Despite this effort, the number of usable organic dyes and of pigments derived from them has been drastically curtailed by regulatory action. 

This technique provides a method of initiating primacord—-and thus any explosive charge—if a regular blasting cap is not available. The device may be rigged as a booby trap with trip wire or it can be fired remotely by the operator. Since the technique does require the destruction of a usable rifle it likely would be used only when there is no other alternative. In addition, care should be taken in all phases of the preparation, because when the weapon is fired it will break into many fragments which would severely injure anyone holding the weapon or close to it. 

For example, when = 200 mW is attenuated to / ml = 20 mW, then the attenuator indicates an output power P = -10 dB (see also Table 2.2). And when / ml = 2 mW, then P = -20 dB. Every additional attenuation by a factor of 10 gives another -10 dB in P. This type of device is usable to 50-60 dB attenuation, which also corresponds to the lower power limit at which the spectrometer is still operable. Note that, in addition to the relative dB scale, microwave engineers also use an absolute dBm scale. The m in dBm is shorthand for milliwatt and defines the reference point of this scale ... 

Another useful device is the carbon-glass thermometer (CGT) [73] usable between 1K and room temperature where it loses sensitivity. A nice property of CGT is its insensitivity to large magnetic fields [74,3, p. 269]. CGT are commercially available,... 

Poly(methylmethacrylate), PMMA, Is a well-known degradable polymer in the radiation chemistry of macromolecule (1). Hatzkis reported that PMMA is an excellent resist material usable in the microfabrication technology for manufacturing the microelectronic devices where X-rays and electron beams are used as radiation sources (2). 

Analyze each SCADA device to determine whether security features are present. Additionally, factory default security settings (such as in computer network firewalls) are often set to provide maximum usability, but minimal security. Set all security features to provide the maximum level of security. Allow settings below maximum security only after a thorough risk assessment of the consequences of reducing the security level. 

When natural gas is used directly in cooking devices, its efficiency can be as high as 90%. Thus, for every 16 g of gas burned, you get about 720 kJ (0.90 X 802 kJ) of usable energy as heat for cooking. This is a much higher fuel efficiency than you can get with appliances that use electrical energy produced in a power plant that runs on a fuel such as coal. 

Peterson, Iver. Smart Guns Set Off Debate Just How Smart Are They The New York Times, October 22, 1998, p. Al. Discusses development of smart gun features by Colt and other companies and debates the effectiveness of devices that would make guns usable only by their owner. Although the idea is attractive, the devices still have technical problems. 

Some of the most generally useful isothermal and adiabatic reactors and a few other devices, all usable under high vacuum conditions, will be described in the following sections. 

The development of novel optical devices requires suitable materials which have the required chemical and photochemical stability, with appropriate optical features, which can also be made into usable forms such as thin films and bulk pieces. Since the sol-gel process9,10,218 219 offers a very attractive possibility with the ability to incorporate organic materials in inorganic matrices at low temperatures in the form of monolithic glasses or thin films, it has opened the way to many possible applications in optics1,60,190,192,193,196,220-222 and electrooptics2,223,224. 

---