The heart is the pump responsible for circulating blood around the body, delivering essential minerals to the body, and carrying away waste product. This chapter describes routine physiological measurement techniques used to assess the hemodynamic, electrophysiological and biomechanical function of the heart. Physiological measurement of pressures and flows allow the diagnosis of disease and enable its severity to be assessed. This chapter describes principles that are fundamental to the measurement of blood flow within the human body. The measurement of blood pressure is described using both invasive and noninvasive measurement devices. Invasive hemodynamic monitoring techniques are explored in detail. These techniques include the Swann–Gantz catheter, which allows the determination of cardiac output using the thermodilution method. Echocardiography ultrasound is routinely used to noninvasively monitor fluid flow and cardiovascular wall structure and movement. Doppler ultrasound physics are introduced and how changes in blood velocity can be measured and used to determine cardiac performance. Electrocardiography (ECG) is routinely used to noninvasively monitor electrophysiological signals generated during the cardiac cycle. Three- and 12-lead ECGs are extensively used within a healthcare environment to provide information on the electrical characteristics of the heart.
This chapter is a general introduction to the subject of health technology assessment and health economics. It provides an overview of cost analysis in healthcare settings. It explains the difference between cost minimization and cost effectiveness. It explains how utility of a technology is measured and how cost effectiveness can be determined. It concludes with discussing why health economics poses some special challenges because of some specific features of healthcare markets.
Lung function testing provides useful diagnostic and prognostic information in patients with pulmonary disease. The most common tests are spirometry, for measuring airflow and volumes; full body plethysmography, for measuring lung volume and airway resistance; and gas transfer, also known as diffusing capacity, used to assess how well oxygen diffuses into the bloodstream from the lungs. This chapter discusses the physical principles behind each of these measurements and the equipment commonly used to perform them.
The background, historical context, and modern-day definition of functional electrical stimulation, or FES, are provided, prior to an explanation of the physiological principles of the subject being described. Following this introduction, the chapter describes the considerations that should be given to designing an FES system and how these are related to patient outcomes. A description of the relevant muscles and nerves is then provided, followed by the generation of the required response and its control specific to application.
Clinical measurement is fundamental to patient diagnostics, and good measurement forms the basis of good science. This chapter outlines the factors pertinent to good clinical measurement within a healthcare environment. The concept that a medical device can be precise but not accurate is explained, and that calibration against a traceable standard before use is crucial for the accurate interpretation of patient data. The idea that measurement error is a combination of human, systematic, and random errors summated is introduced. Measurement uncertainty, and the process of using Type I and Type II errors in hypothesis testing is described.
This chapter describes electrical safety testing of medical electrical equipment which is an integral function of Clinical Biomedical Engineers working in hospitals. It is a very important part of the job to ensure that the organisation complies with the law, meets national guidance (e.g. Medicines and Healthcare products Regulatory Agency (MHRA) in the UK), meets good engineering practice, complies with manufacturer's requirements and addresses clinical staff and patients' expectations. The IEC 60601 series is an International set of standards for electrical safety of medical electrical equipment and the structure and scope of the series are introduced. The three main physiological effects of electricity on the human body are described. The two methods of protection against electrocution according to the electrical safety class of the equipment are discussed. Finally, the process of performing field testing with an electrical safety tester is described.
This chapter builds on the preceding two chapters, which covered wheelchair assessment and prescription. It describes the reasons why a powered wheelchair might be considered before dealing with those factors of wheelchair prescription specific to powered chairs. Wheel layout, powered seating configurations, safety considerations, control interfaces, and specialized controls are described in detail. Various pieces of equipment have been produced over the last 20 years to provide powered assistance to manual wheelchairs, operable either by the user or by the attendant. These are included in the discussion as there are occasions where the line between powered and manual chairs becomes blurred.
The wheelchair is but one mode of mobility. In this chapter other common forms are discussed, such as walking frames and mobility scooters. Importance is attributed to the significance of mobility to the developmental needs of children and how equipment can either help or hinder this process. Environmental barriers to mobility are discussed, together with adaptations that can be made to address these problems. An overview of what is required from a wheelchair assessment is given, detailing the most critical medical, functional, social, and environmental factors to investigate, coupled with a description of the physical measurements that should be made and considerations of posture assessment. A method is described for setting objectives and developing conceptual ideas before finally deciding on a prescription.
The complete range of electromedical devices and systems bought by a hospital constitutes a valuable financial asset with capital and revenue resourcing requirements. Their selection, procurement, upkeep, and life cycle need to be carefully managed to ensure they are cost effective, up to date, and continue to support the corporate objectives of the healthcare organization. Managing healthcare technology and the risks involved should be governed by a strategic, organization-wide policy that informs and guides those who use and manage the technology. The term healthcare technology management (HTM) describes the scientific and technical support and financial stewardship of medical devices and clinical information technologies for the benefit of patients. This chapter focuses on the medical device management aspect of HTM, describing how clinical engineers manage the medical devices, ensure they are maintained in a satisfactory condition, and are kept available for use. This includes a discussion of how to develop device-specific equipment support plans and how to deal with the challenges of assigning often limited resources to execute these plans. The importance of delivering a health technology management programme within a quality cycle is emphasized.
Electrophysiological measurements are used to support the diagnosis and nature of neurological conditions. They are used to infer the structure of the nervous system. This chapter looks at several techniques that use the electrical fields developed from the movement of ions in the body that directly relate to the operation of the central and peripheral nervous system. The study of muscle activation, electromyography, is considered in its broadest sense, and then two specific situations are studied: during movements such as walking, and nonfunctional or evoked movements. The chapter then looks at different aspects of the neurological system from vision to brain function. Because interpretation is so closely linked to how we capture and process the signals, we briefly look at some signal-processing issues related to neurological measurements.
The CITI Good Clinical Practice (GCP) Optional Modules Course is a 13-module program that discusses good clinical practice as it relates to clinical trials of both drugs/biologics as well as devices. The GCP modules are described below and are intended for use by research personnel involved in conducting drug, device, or biologic studies and should be taken in the order they are listed. The optional course takes approximately 4 hours to complete.
