Content Listing

Summary

This book is designed to introduce the reader to the fundamental information necessary for work in the clinical setting, supporting the technology used in patient care. Beginning technicians/ technologists can use this book to develop a working vocabulary and fundamental knowledge of the Healthcare Technology Management (HTM) profession. Content includes a wide variety of medical technology, with an emphasis on device types and classifications; individual manufacturers are utilized as examples.

This work is intended for the reader with a fundamental understanding of anatomy, physiology, and medical terminology appropriate for their role in the healthcare field, and assumes the reader's understanding of electronic concepts, including voltage, current, resistance, impedance, analog and digital signals, and sensors. The material covered in this book will assist the reader in the development of his or her role as a knowledgeable and effective member of the patient care team. The second edition features revisions to all of the content to reflect changes in healthcare, regulations, standards, and technology. A new chapter addresses device testing, with emphasis on safety inspections. A second new chapter explores the interface of medical technology with the electronic medical record.

A vital connection exists between technology and the care of patients. In many cases, healthcare workers depend on technology to administer care or treatment or to make a diagnosis. This book helps readers understand how technology is tightly woven into patient care. The role of technical support for the medical team is, therefore, essential in the delivery of effective medical care.

The section of each chapter entitled “For Further Exploration” encourages readers to use the Internet to obtain in- depth information about a related topic. The questions are designed to push the reader to integrate concepts and ideas using external sources. Answers to the questions are not specifically available within the chapters. Research exercises encourage one of the most important professional skills – the ability to investigate topics that are not well understood. In the clinical setting, it is virtually impossible to be an expert about all technology and aspects of patient care. The ability to effectively search for information is vital.

Summary

Introduction

Technology is used to support heart function in numerous ways. Perhaps the most common and well- known device is the defi- brillator. In addition, the amazing life- saving powers of artificial hearts and implantable devices regularly capture the attention of the public and news media.

ACLS (advanced cardiac life support) is a detailed protocol to provide life- saving cardiac care. HTM professionals may be involved in the selection of technology and technical protocols used in a crisis. In addition, technicians may help establish training programs and awareness of the medical devices involved in emergency response.

Defibrillators

A defibrillator is familiar to most only from life- saving moments on television medical shows, but is often used in real life as first responders seek to help those with medical emergencies. It is a fairly simple device that delivers a large amount of energy across a patient's chest when the heart is not beating properly: that is, when the pacemaker of the heart, the sinoatrial (SA) node is not properly generating a periodic waveform. When the heart is not beating with a pattern, all cells are contracting at different times, this is known as fibrillation. Defibrillators, or defibs (as they are often called) in use today send about 3,000 volts (V) – up to 20 amperes (A) – across a patient's chest. (Note: The amount of voltage and current vary tremendously based on the patient's size and therapeutic settings.) This large amount of energy causes all cells in the heart to depolarize at once. This action may allow the SA node to resume function and generate a normal electrical pattern. Sometimes the SA node can recover and resume electrical control of the heart, but sometimes it cannot. The shape of the energy waveform delivered by a defibrillator has evolved with experience. The Lown waveform was the therapeutic waveform standard until recently. It looks like a damped sine wave.

The biphasic waveform is the standard of care in defibrillators today. It has both a positive and negative component and produces much better results for patients more quickly. Because it better simulates the electrical conduction pattern through the heart, biphasic waveforms are able to deliver results with less energy. The waveform is approximated in Figure 8.1.

Summary

Introduction

As part of the healthcare team, technicians must ensure medical technology is safe and available when needed by clinicians. In the healthcare workplace, work is done to ensure a device is operating properly. This is in contrast to corrective actions designed to remedy problems as a result of a device malfunction. The kind of work described in this chapter is focused on reducing equipment failures and discovering hidden problems before they could impact patient care or device performance.

Clinical sites and administrators generally define the scope of medical equipment managed by HTM technicians. As discussed in Chapter 2, medical technology is often grouped into three broad categories: therapeutic, monitoring, or diagnostic. Variation among hospitals is common based on historical support or individual skill sets, although devices that are disposable or singleuse and most implantable devices are beyond the responsibility of the HTM technician.

Before any work begins on any medical device, technicians should be sure to utilize appropriate personal safety measures as discussed in Chapter 5.

Device Inspection

When a new device is delivered to an institution, removal from the packing materials, initial assembly, and incoming inspection is performed. The complexity and time required to complete these steps varies greatly depending on the device. As mentioned in Chapter 1, incoming inspections are an essential part of the HTM technician's workload, with efforts focused on the assurance that a new device will function properly when put into service within the healthcare setting.

Preventative maintenance, another important workplace responsibility, evaluates the performance of an existing device to ensure proper operation. These activities are typically scheduled utilizing a predetermined timeline (such as once per year). The goal of these actions is to identify undetected problems before they impact patient care, reducing equipment downtime and reducing overall hospital costs.

Simple visual inspections look for signs of deterioration, damage, or missing hardware. The stressful clinical environment may result in unintended equipment mishandling that can cause broken plastic parts, missing doors or knobs, frayed power cords, or gashes. Power cord damage, especially at the junction with the device, can be both common and potentially hazardous. Experience in healthcare settings will offer technicians the opportunity to see a wide variety of device damage (some surprising and inexplicable), and to develop a special sense to predict and find device deterioration.

Summary

Introduction

The use of technology to push fluids into the circulatory system of a patient has evolved and expanded over time. In the past, glass bottles of fluids utilized gravity to promote fluid flow to “drip” fluids into a patient. As technology expanded into healthcare, the bottles were replaced with plastic bags and gravity was no longer medically adequate. Electromechanical pumps are more reliable and provide constant monitoring of fluid delivery. In addition, the flexibility of some pumps has improved medication dosing and caloric delivery. Healthcare has come to depend on the use of technology to deliver fluids and medications to patients.

Infusion Pumps

One of the most common pieces of equipment in the hospital, the infusion pump (also called intravenous pump, IVAC, and IV pump) delivers medication, blood, or fluid into the patient over a specific period of time at a particular rate. The name used may reflect brand names from the past, including IVAC. Many patients will be connected to several pumps delivering fluids to the patient through a vein (hence, the term “intravenous”). The pump ensures an accurate rate and, therefore, an exact dose. In addition, should there be a problem with the fluid delivery, an occlusion (blockage of the tubing) perhaps, or the complete fluid amount has been delivered, an alarm will sound to alert staff. The electronic monitoring allows delivery of IV fluids with minimum human intervention.

Bags, filled with fluids of many kinds, are hung on poles, connected through tubing to the pump, and then through the pump to the veins of the patient. Settings on the device include delivery/ flow rate as well as alarms to indicate blockages or empty fluid bags.

There are different techniques employed to pump in the fluid. One of the most common is a peristaltic pump. Rollers (in most cases) squeeze the tubing to push in the fluid. Traditional tubing from the fluid- filled bag to the patient is used.

Another method requires some additional disposable cassettes that hold the liquid for a piston to push the liquid. This requires that the infusion tubing be specifically chosen to work with the type of pump the hospital owns.

Summary

Introduction

The focus of this chapter is external human respiration. Moving air in and out of the lungs is external respiration and the focus of technological interventions. The exchange of gases in the alveoli is part of external respiration (although it occurs within the lungs) and reflects the effectiveness of breathing – note that internal respiration does not mean “inside the lungs,” it refers to the gas exchange at the cellular level within the tissues. Patients need to move air in and out of the lungs and exchange gases in the alveoli, a substructure of the lungs. Oxygen is taken in by the body and carbon dioxide is expelled. Air is made up of 79% nitrogen, 20.96% oxygen, and 0.04% carbon dioxide. However, the air that is expired out of the lungs contains differing percentages. Expired air still contains 79% nitrogen (unaffected by respiration), but notice that the concentration of oxygen is decreased to 17%, and the concentration of carbon dioxide is substantially increased to 4%.

Respiration Effectiveness

One important patient characteristic that is monitored is the effectiveness of respiration – a patient may be breathing (air moving in and out), but it is more important to know whether this activity is resulting in appropriate oxygenation of the body. One method to examine breathing effectiveness is to evaluate the properties of a patient blood sample. Chemical analysis of blood (often performed at the bedside or in the unit), especially the measurement of pH (i.e. the acidity of the blood), can help clinicians determine a patient's respiratory status. See Chapter 15 for more information regarding blood testing.

Pulse oximetry, as discussed in Chapter 7, is also used to simply and non- invasively characterize the effectiveness of respiration. The percentage of hemoglobin molecules that carry oxygen can be displayed by a simple device and will increase or decrease as the body is able to absorb and circulate oxygen.

Capnography is the measurement of carbon dioxide concentrations in expired air. This technique evaluates the changes in carbon dioxide values over time. Expired air is sampled or passed through sensors that can electronically detect the concentration of carbon dioxide. Sensors that utilize infrared (IR) light and light detectors are typically placed within the tubing that connects patients with respiratory devices.

Summary

Introduction

The clinical laboratory is vital to a hospital's ability to treat patients. Bodily fluids from patients are analyzed for their chemical makeup as well as evidence of disease. Many therapeutic and treatment decisions are made based on the results of this important analysis. Almost all testing is automated and most devices perform many tasks. As a very equipment- intensive department, technical support is vital. The high level of complex equipment does require some hospitals to obtain service contracts for the support of clinical laboratory equipment.

Common fluids from patients analyzed include blood, urine, and cerebrospinal fluid. A tremendous number of categories and tests are performed. This chapter focuses on the principles that form the foundation for the complex equipment. Most devices utilize multiple reagents, bar codes, robotics, and computers to perform the sample preparation and multiple tests. In addition to automated fluid analysis, many laboratory tests evaluate tissue and fluid samples for evidence of abnormalities. Many of these tests are not automated and require the expertise of a pathologist or clinical laboratory technician.

The naming conventions associated with this part of healthcare have varied over time. Originally termed medical technology, a shift was made to more clearly identify the profession. Previously, clinical staff who managed sample analysis techniques were known as “med techs,” causing confusion with medical assistants, phlebotomists, and HTM technicians. Now laboratory staff are often called clinical laboratory scientists. Newer labels for the department include medical laboratory, clinical laboratory, and clinical technology.

Clinical laboratories have their own specific regulations, and organizations that offer guidelines and best practices. These include the American Association of Blood Banks (AABB), College of American Pathologists, and Clinical Laboratory Improvement Amendments (CLIA). CLIA observance is a federal requirement.

Blood Analysis

Many tests are performed on blood. A common test is blood cell count. The automation of this test was vital to improvement in analysis speed. W. H. Coulter created an automated method of particle counting using electrical impedance. As the blood cells pass between electrodes, the impedance increases in pulses. These pulses can be counted to determine the amount of cells (particles) in a sample. Since red blood cells and platelets have different sizes, the pulses vary in size. This allows for very specific results.

Summary

Introduction

The technology involved in imaging the inside of the human body is tremendously complex and amazingly broad. There are a vast array of unique devices, but this chapter will deal with general categories of imaging modalities based on the technique or source of image.

Common Imaging Modalities

Ultrasound: this imaging technique uses sound waves to image anatomy and physiology function. Ultrasound can also be used to detect blood flow, anatomic movement (heart valves, for example), and, most commonly, anatomical structures. It is frequently chosen as an imaging modality because it does not use radiation and carries less risk to the patient. Ultrasound imaging uses highfrequency sound waves (1– 20 MHz) which are projected into the body. The waves hit an object, bounce back, and are detected with a piezoelectric crystal sensor (as discussed in Chapters 6 and 9). The distance from the transmitter probe and the anatomical structure can be calculated, and this data is used to produce an image. Computers can manipulate the transducer data to present three- dimensional or moving images.

Transducer probes, which contain both the transmitter and the sensor, come in many shapes and sizes. Some are designed to enter body cavities such as the esophagus or the vagina for better imaging quality. Most commonly, probes are placed on top of the skin and transmit high- frequency waves into the soft tissues. Ultrasound waves are generally blocked by air and bone. This can be a problem since air is contained in the lungs and there are bones surrounding some organs like the brain and heart. However, creative approaches to bypass bones (between the ribs, for example) are utilized to image most organs. In addition, a gel is often used to help block any air between the probe and the skin. This ensures effective transmission of the waves and an unobstructed image. An example of a probe used for a trans- thoracic (cardiac) ultrasound is shown in Figure 14.1.

Because of the inherent safety of this type of imaging, women often undergo ultrasound imaging to evaluate the progress of pregnancy. Many abnormalities can be detected early and, in some cases, perinatal treatment can take place. Another common application of ultrasound is echocardiography. The anatomy and function of the heart can be examined.

Summary

Introduction

An important responsibility of the HTM profession is related to patient safety. Ensuring the safe use of technology is a vital role of the HTM technician as part of the medical care team. Understanding the human body and its interaction with technology is critical to patient safety.

Healthcare Technology

Many forms of technology are utilized as tools in medical care. The devices must be safe and effective. In addition, the devices must perform in a way that healthcare providers expect, consistently and reliably. Devices range from very simple (without electricity or moving parts) to highly complex (imaging devices). In general, devices fall into three categories: therapeutic, monitoring, or diagnostic.

Summary

Introduction

The beat of the heart and the electrical signal transmitted to create the beat is one of the most familiar waveforms found in healthcare. The waveform deserves this status. The electrical activity of the heart is fairly simple to measure and tells a great deal about the health of the patient. In the very early 1900s, Willem Einthoven invented the electrocardiogram and won the Nobel Prize in medicine for this work.

Patient Monitoring

Monitoring a patient's heart is a very common procedure. A patient's vital signs are often tracked at regular time intervals or continuously (vital signs usually include blood pressure, related to heart function). Using technology means the patient's condition can be tracked without the need for someone standing next to the bedside continually taking measurements. In addition to tracking the condition of a patient continuously, monitoring can provide diagnostic information upon which treatment decisions are based. Vital signs such as blood pressure and respiration are discussed in their respective chapters.

Note about assumptions for vital signs: Most patients in most hospitals are adults (they are simply sicker more often). Therefore, when a vital sign is listed and unlabeled (as to the age/ type of patient) it is assumed to belong to an adult.

Electrical Activity of the Heart

The heart generates electrical signals to contract (pump blood). Cells within the heart have the ability to depolarize and repolarize, and this process generates electrical energy. The electrical signal in the heart begins at the sinoatrial (SA) node, which stimulates the atria (the two upper chambers of the heart) to contract. The signal then travels to the atrioventricular (AV) node, followed by the Bundle of His, and then through the Purkinje network, which stimulates the ventricles (the two lower chambers of the heart) to contract. When the ventricles are being stimulated to contract, the atria are repolarizing.

The electrical signal is called an electrocardiogram. The abbreviation used for this can be EKG (which comes from German Elektrokardiogramm) or ECG (you will find these letters used interchangeably). Some people prefer the term EKG since it is less likely to be confused with the term EEG when spoken. Generally, little consensus exists upon the use of the label EKG or ECG, although the EKG seems to be diminishing in clinical use over time. There may be times when the terms are used together.

Summary

Introduction

Many facets of healthcare delivery engage technology as part of patient care, but they do not fit neatly into the traditional categories discussed so far. Some devices are found in specialized areas of the healthcare setting, others found at every bedside. Children use technology (game consoles, for example) in play therapy. Women in labor are monitored using specific equipment. In addition, specialists such as physiotherapists and occupational therapists use many forms of technology. This chapter will explore these various technologies.

Play Therapy

Children's toys have increased in technological complexity over time. The role of play in a patient's recovery is well documented, and technicians support this endeavor. HTM professionals ensure the devices are safe to use in the clinical setting, are secure from theft, can be cleaned appropriately, and are repaired when needed. In addition, some devices need adaptation to suit the needs of a particular patient. Technicians employed in children's hospitals face these challenges utilizing creativity and sensitivity.

Fetal Monitoring

Fetal monitors are utilized to gather information about the fetus and mother, typically tracking uterine contractions and fetal heart rate simultaneously, sometimes printing the information on long strips of paper. The medical team uses the two pieces of information together to evaluate fetal health and labor progress. A fetal monitor is shown in Figure 18.1. Fetal heart monitoring is decribed in more detail in Chapter 7. This monitoring can use indirect measurements or direct, electrical measurements.

Indirect monitoring, called Doppler fetal heart monitoring, uses a transducer placed on the woman's abdomen. The device detects the movement of the fetal heart and converts the motion into sound. Many devices display a fetal heart rate: beats per minute (BPM).

Direct fetal heart monitoring uses an electrode attached to the fetal scalp and a reference electrode on the mother's skin. The measurement technique directly detects the fetal heart electrical activity. This monitoring method requires that the fetus be in a head- down presentation for delivery. In addition, the amniotic membranes which surround the fetus must not be intact.

Monitors used in labor can also measure the strength and duration of contractions. A pressure sensor (strain gauge) is placed externally on the mother's abdomen. The tightening movements of the abdominal muscles with each contraction are detected with the transducer.

Summary

Introduction

Healthcare settings are regulated by a wide variety of groups. Some groups have direct control over operations, such as the state board of health for a hospital. Others offer voluntary guidelines to follow in order to receive insurance payments for patients treated. Some environments have only a few requirements, such as when healthcare is delivered in the home. Understanding the myriad of guidelines, recommendations, and laws is helpful in promoting compliance and supporting safe patient care.

Codes and Standards

The Association for the Advancement of Medical Instrumentation (AAMI) and several other non- profit organizations have developed standards for best practices through consensus within the HTM profession. The standards are not legal requirements but recommendations for compliance. Some examples of AAMI standards are EQ56 Recommended Practice for a Medical Equipment Management Program and EQ89 Guidance for the Use of Medical Equipment Maintenance Strategies and Procedures.

The National Fire Protection Association has established recommendations for healthcare with NFPA 99: Health Care Facilities Code. The National Fire Protection Association first established the code in 1984 “to minimize the hazards of fire, explosion, and electricity in health care facilities providing services to human beings.” Code 99 applies to healthcare and the technology used within many types of clinical settings. The entire code is available online at www.nfpa.org. Some states have adopted NFPA 99 as state law. When states adopt these standards as law, the guidelines become absolute legal requirements.

The NFPA 99 code is revised from time to time. The latest version of the code was released in 2012. References to the 2012 edition code will be made in this chapter.

NFPA 99 Definitions

Anesthetizing locations: An area of the facility designated to be used for the administration of nonflammable inhalation anesthetic agents. (Flammable anesthetics, such as ether, are no longer used in this country. There were many precautions and regulations when flammable anesthetics were used.) Chapter 13 reviews the four types of anesthesia but only when general anesthesia is delivered is the area designated an anesthetizing location by NFPA 99. The other types of anesthesia are not subject to the requirements of anesthetizing locations.

Summary

Introduction

As part of the healthcare team, technicians must strive to serve the staff and patients in the safest and most effective ways possible. This chapter will explore important workplace characteristics that go beyond technical and analytical skills. The first section will review the various ethical codes that may guide the practice of the profession. Understanding personal safety and infection control can promote workplace safety. In addition, the task of serving staff and patients requires excellent customer service skills and professionalism.

Applicable Codes of Ethics

No code of ethics specifically and exactly addresses the needs of HTM technicians. Two codes, however, have parts that apply. First, there is the Code of Ethics from the Biomedical Engineering Society (www.bmes.org). Even though this group is research oriented, they do have a section that applies to technicians in the hospital environment.

Biomedical Engineering Professional Obligations

Biomedical engineers in the fulfilment of their professional engineering duties shall:

Summary

Introduction

Blood pressure is an important indicator of performance of the human heart, lungs, and circulatory system. Blood pressure is relatively easy to measure, and readings can be taken at specific time intervals to track patient health. The peak and resting pressure of blood within the arteries is the most commonly measured blood pressure vital sign. Blood pressure rises and falls as the heart beats and has a periodic waveform. The amount of pressure in the heart can reflect the overall health of a patient and can be an indicator of many diseases and conditions.

Indirect Measurement Methods

Techniques to determine blood pressure without entering the circulatory system (i.e. non- invasive) utilize relationships between heart blood pressures and pressures observed in the extremities. The most common non- invasive blood pressure (NIBP) measurement method involves a blood pressure cuff and a stethoscope (see Figure 9.1). The cuff is connected to a gauge that displays pressure in the cuff. The blood pressure cuff is usually placed around the arm and inflated to various pressures displayed on the gauge. The manual technique involves a person using the stethoscope to listen to Korotkoff sounds. The sounds are related to blood flow in the vessels of the arm. Listening to body sounds is an auscultatory method of measurement. These sounds are related to the equalization of pressures between the arm blood vessels and the pressure in the heart. This technique has been in use for many, many years.

A sphygmomanometer is a gauge and cuff combination that is utilized for the manual measurement of blood pressure. The cuff inflates with air and the pressure inside the cuff is displayed on a gauge. The pressures are reported in millimeters of mercury (mm Hg), even though most hospitals have disallowed the use of mercury.

Systolic pressure is the highest pressure in the heart and is measured when the heart is contracting. Diastolic pressure, the lowest pressure in the heart, occurs when the heart is filling.

These high and low pressures correspond to Korotkoff sounds in the vessels in the arm. Blood pressures are typically reported as a two- number ratio: systolic pressure “over” diastolic pressure. Typical adult pressures are 120 mm Hg for systolic pressure and 80 mm Hg for the diastolic pressure.

Summary

Introduction

Patients who are very ill or in a serious condition will usually be found in the intensive care unit (ICU). Although these patient care vicinities may be called various names, they have some similar qualities. Generally, intensive care units deliver highly specialized care and have a very large amount of technology involved in patient monitoring and treatment. Technical staff who work in this area need to understand the characteristics and special needs of intensive care units.

Each hospital in the United States has its own way of organizing and providing intensive care. For example, some hospitals do not separate surgical and medical patients. Some hospitals include transplant patients in their medical units, whereas others send transplant patients to the surgical floor and still others have stand- alone transplant intensive care units. It is virtually impossible to address the variations in this chapter. However, the issues important to intensive- care patients and staff who care for them transcend the hospital- defined categories.

Characteristics of Intensive Care Units

Some smaller or rural hospitals may not provide a high level of intensive care; consequently, patients who need intensive care are transferred to other hospitals. Here are the main characteristics of intensive care units:

Summary

Introduction

Measuring the activity and function of the brain is more complex than measuring the electrical activity of the heart. Signals from the brain are more random and have only recently been translated for use in specific applications. Even though brain signals can be extremely useful in patient assessment, in general, measuring the function of the brain is far less common than other technology- facilitated patient care tools.

Review of Neuroanatomy and Physiology

Here is a brief review of basic neuroanatomy and physiology terminology.

Summary

Introduction

Patient records generated during a stay at the hospital, including vital signs, test results, and notes by clinical staff, traditionally included a thick stack of papers stored in a binder at the bedside, or over time, with other charts at the nurses’ station. Dramatic shifts in record- keeping are underway, expanding the use of computers and computer networks to maintain patient charts and test results. The complexity of the challenge to connect devices, to transcribe information directly into a computerized system, will demand new information technology (IT) skills.

The Electronic Medical

Record Evolution

Computers have been used in healthcare for a very long time as a tool to gather and maintain billing information. However, initially, most computerized records were limited to non- patient care information. As noted in Chapter 3, the Health Insurance Portability and Accountability Act of 1996 (HIPAA) was perhaps the first significant regulatory step to address information technology in the healthcare setting, promoting privacy and security.

A major investment into the application of information technology within healthcare was driven by the American Recovery and Reinvestment Act (ARRA) adopted February 13, 2009. The Health Information Technology for Economic and Clinical Health (HITECH) Act part of ARRA offered financial incentives to hospitals to provide electronic medical records, driving the move from paper records to electronic files. Deadlines were set to speed hospitals toward change: 2012 was the first deadline for an electronic patient file. Additional deadlines were set with the aim of expanding communication to include clinical laboratory results and other healthcare information.

The Electronic Medical Record (EMR) or Electronic Health Record (EHR) are broadly defined tools designed to house medical information electronically. Ideally, each person would have one electronic medical record that would receive contributions from all healthcare providers, archiving all medical data, and all information could be shared between providers. EMRs are expected to improve the efficiency of healthcare, improve access to information, preserve complete records without gaps, and provide safer healthcare at lower cost. However, these benefits depend on significant integration between a multitude of clinical services and users.

The EMR did not specifically impact the HTM profession until clinicians sought to include physiological data directly from medical technology into the electronic record.

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