Introduction to Biomedical Instrumentation: The Technology of Patient Care

Citation

Christe, B. L. (2017). Introduction to Biomedical Instrumentation: The Technology of Patient Care (2nd ed.). Cambridge University Press.

Chapter Summary

The second edition is a compact book of 18 chapters on about 225 pages. Christe's preface addresses it to beginning technicians and technologists entering Healthcare Technology Management (HTM), the hospital profession that keeps medical equipment safe, effective and available, and says it aims to give them a working vocabulary and fundamental knowledge of the field. Devices are discussed by type and classification, with individual manufacturers as examples. The preface assumes basic anatomy, physiology and medical terminology, and an understanding of voltage, current, resistance, impedance, analog and digital signals, and sensors. The second edition revised all content and added two chapters, on device testing and on the electronic medical record. Each chapter ends with a "For Further Exploration" section of research questions whose answers lie outside the book; solutions to end-of-chapter questions and additional documents are provided online.

Chapters 1–5: A Career in the HTM Profession; Patient Safety; NFPA and Other Guidelines; Device Testing; In the Workplace

The opening group introduces the profession rather than the devices. Chapter 1 explains the many job titles (HTM technician, BMET, "biomeds", clinical engineers) and who employs them: hospitals, independent service organisations and manufacturers. Chapter 2 classifies devices as therapeutic, monitoring or diagnostic and by risk, and discusses balancing benefit and risk. Chapter 3 surveys the regulatory landscape, from consensus standards of the Association for the Advancement of Medical Instrumentation (AAMI) to the NFPA 99 Health Care Facilities Code. Chapter 4, new in this edition, covers incoming inspection, preventive maintenance and safety inspection. Chapter 5 deals with professional codes of ethics (from the Biomedical Engineering Society and the American College of Clinical Engineering), personal safety, infection control and customer service.

Chapter 6: Electrodes, Sensors, Signals, and Noise

The connection between patient and machine: passive sensors such as strain gauges, thermistors and photoresistors, active sensors such as piezoelectric crystals, LVDTs and thermocouples, and the electrodes, signals and noise involved in patient monitoring.

Chapters 7–11: The Heart; Cardiac Assist Devices; Blood Pressure; Respiration and Respiratory Therapy; The Brain and its Activity

Device chapters organised by body system. Each starts from the physiology (for example, the conduction pathway of the heart, the meaning of systolic and diastolic pressure, external respiration) and moves to the equipment: ECG and patient monitors, defibrillators and their waveforms, artificial hearts and implanted devices, non-invasive and invasive blood pressure measurement, pulse oximetry and capnography, and EEG.

Chapters 12–13: The Intensive Care Unit; The Operating Room

Two chapters organised by clinical setting rather than device. The ICU chapter describes the characteristics of intensive care (constant monitoring, ventilator-dependent patients, many lines and tubes) and the monitoring typically used there; the operating room chapter covers the equipment of surgery, including the types of anaesthesia.

Chapters 14–16: Imaging; Clinical Laboratory Equipment; Intravenous Pumps and Other Pumps

Imaging is treated by general categories of modality grouped by technique or source of the image, beginning with ultrasound; the clinical laboratory chapter explains the principles behind automated analysers, such as impedance-based cell counting, and the laboratory's own regulations; the pump chapter covers infusion pumps, their pumping mechanisms and alarms.

Chapters 17–18: Electronic Medical Record and IT; Miscellaneous Devices and Topics

Chapter 17, the second new chapter, traces the move to electronic records driven by the HITECH Act and the growing need for HTM staff to connect devices to information systems. The final chapter gathers technology that fits nowhere else, such as play therapy devices in children's hospitals, fetal monitoring, and equipment used by physiotherapists and occupational therapists.

Key Concepts

Chapters 1–5: The Profession and Its Rules

• Healthcare Technology Management (HTM): the hospital discipline that combines patient safety, medical technology and financial stewardship to keep equipment safe and available.
• Device classification by function and risk: therapeutic, monitoring and diagnostic devices; high-, medium- and low-risk technology.
• Standards and codes: voluntary consensus standards such as those from AAMI, and codes such as NFPA 99 that become legal requirements where states adopt them.
• Incoming inspection and preventive maintenance: scheduled checks that find hidden problems before they affect patient care.

Chapters 6–11: Signals and Body Systems

• Passive and active sensors: sensors that change a resistance, capacitance or inductance versus those that generate a voltage or current.
• ECG and defibrillation: recording the heart's electrical activity, and delivering energy to restore its rhythm, with biphasic waveforms now standard.
• Non-invasive and invasive blood pressure: cuff-based auscultatory or automated methods versus direct arterial measurement.
• Pulse oximetry and capnography: non-invasive measures of how effective breathing is.

Chapters 12–18: Settings, Systems and Information

• Care settings: the ICU and the operating room as environments with their own technology and constraints.
• Infusion pumps: devices that deliver fluids and drugs at a set rate, with alarms for occlusion and completion.
• Electronic medical record integration: connecting devices to hospital information systems.

Critical Analysis

Strengths

• Written for the hospital technician. The book's perspective is that of the person who inspects, maintains and supports equipment in clinical use, not the designer. Chapters on careers, regulations, testing, workplace ethics, infection control and customer service cover what engineering texts usually omit.
• Clinical context first. The device chapters open with the relevant physiology and the clinical purpose of the measurement before the technology, and two chapters describe whole care environments (ICU and operating room).
• Updated for practice. The second edition revised all content and added chapters on device testing and on the electronic medical record, two growing parts of HTM work. Ted Lucidi of Pennsylvania State University, quoted by the publisher, praises the update and the "For Further Exploration" sections that point to current information.
• Trains research skills. The further-exploration questions deliberately require outside sources, which the preface links to a key professional skill: finding information about unfamiliar technology.

Limitations

• Descriptive, not quantitative. Devices are explained at the level of function, block diagrams and practical concerns; there is no circuit analysis or design mathematics. Engineering students will need another text to learn how instruments are designed.
• United States regulatory frame. The regulatory material centres on US bodies and rules (AAMI, NFPA 99, CLIA, HITECH), and the NFPA chapter refers to the 2012 edition of the code, which has since been revised. Readers elsewhere, or after further revisions, must check current requirements.
• Breadth over depth. Eighteen chapters in about 225 pages means many device classes get a few pages; imaging, for example, has one chapter for all modalities.

Where It Fits in the Course

Among the books on medical instrumentation, Christe's is the one written from the hospital rather than the laboratory or the design office. Webb's Principles of Biomedical Instrumentation, a similarly accessible text, follows the design of an instrument from sensor through amplification, filtering and digitisation to safety testing; engineering students should read it alongside or after Christe to learn how the devices described here are built. Webster and Nimunkar's Medical Instrumentation: Application and Design is the standard engineering treatment of sensors, signal conditioning and clinical measurements and the natural next step for design work.

Togawa, Tamura and Öberg's Biomedical Sensors and Instruments and Cobbold's Transducers for Biomedical Measurements go deeply into sensing principles, the subject of Christe's Chapter 6. Northrop's Analog Electronic Circuits for Biomedical Instrumentation is a graduate-level text on the electronics between sensor and digitiser. For students in a biomedical equipment technology or clinical engineering programme, Christe can be the main text; for engineering students it serves best as the clinical companion to a design-oriented book.

How to Use This Book

The book suits students in biomedical equipment technology and HTM programmes, new hospital technicians, and engineering students who want to understand how equipment is used, regulated and maintained in patient care. Readers need the background the preface lists: basic anatomy, physiology and medical terminology, and electronics up to impedance, signals and sensors.

A practical plan:

• Core: Chapters 1–6 in order. They establish the profession, safety, regulations, testing and the patient–device connection on which the device chapters depend.
• Device chapters: Chapters 7–11 in order, since later chapters refer back to the heart and blood pressure material; then Chapters 14–16 according to the reader's work setting.
• Settings and systems: Chapters 12–13 after the device chapters, as they draw the devices together into clinical environments; Chapter 17 for anyone who will connect equipment to hospital networks.
• Optional: Chapter 18.

Do the "For Further Exploration" questions: they are designed to be answered from outside sources and train the information-searching skill the preface emphasises. Check every cited code and standard against its current edition, and if possible pair each device chapter with time in a hospital equipment shop or a manufacturer's service manual for one device of that class.