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1869 results in Biomedical engineering

Page 24 of 94

  • 14 - Imaging

  • Barbara L. Christe, Indiana University–Purdue University, Indianapolis
  • Book:
    Introduction to Biomedical Instrumentation
    Published online:
    06 August 2018
    Print publication:
    07 December 2017, pp 175-188

  • 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.

  • 1 - Implantable Wireless Medical Devices for Gastroesophageal Applications

  • Edited by Isar Mostafanezhad, University of Hawaii, Manoa, Olga Boric-Lubecke, University of Hawaii, Manoa, Jenshan Lin, University of Florida
  • Book:
    Medical and Biological Microwave Sensors and Systems
    Published online:
    14 December 2017
    Print publication:
    07 December 2017, pp 1-39

  • Summary

    Introduction

    Advances in low-power-consumption radiofrequency integrated circuits (RFICs), multifunctional integrated circuits, high-sensitivity sensing electrodes, biocompatible materials, and packaging techniques have made implants with wireless communication functionality and/or wireless charging capability more feasible and practical. However, wireless communication or wireless powering has not been widely used in implants. There are several challenges. The implant applications are typically disease oriented and implementation focused. The designs of implants have to address specific needs in the disease diagnosis or treatment modalities, which are strongly related to both electronic and mechanical parameters. The sensing modalities or therapy methods determine the electrical specifications, while the biological environments often present serious design constrains. The implementation has to suit clinical settings for safe, cost-effective, and relatively easy implantation procedures and, most important, the needs and comfort of patients in daily life.

    It is obvious that integration of wireless communication functionality in implants can provide critical and increased capabilities in applications. The outbound communication brings sensor signals and device conditions to the reader outside the body. The sensors can monitor physiologic signals, such as blood pressure, intracranial pressure, core temperature, electrical signals of tissue or motility of organs, and biochemical conditions such as pH and certain protein or factor concentrations, of patients in vivo and in real time. In addition, the wireless communication can periodically report device conditions such as battery level, electrical resistance of electrodes, and current/voltage delivered to tissues. The inbound communication can be used for device reconfiguration, dosage setting, and condition probing. Bidirectional communication will be ideal for remote access of the implants, adding capabilities for real-time feedback as an integrated system between body and computer. The wireless closed-loop system also can provide real-time patient condition alerts, patient self-diagnosis using smart phones, and autonomous treatment-efficacy studies over a population of patients.

    From the perspectives of patients, wireless communication removes the discomfort and inconvenience of tethered wires coming out of the body. Currently, the wires either go through small surgical openings in the body, such as for the extension wire from the head in deep brain stimulation, or an orifice, such as the nostril for stomach stimulation and multichannel intraluminal impedance tests or the urethra for bladder monitoring. The tethered wires connecting to the external electronic device, either a reader or a pulse generator, obviously bring some inconvenience to patients and sometimes pain, and they often limit patient mobility, hindering quality of life.

  • 2 - Patient Safety

  • Barbara L. Christe, Indiana University–Purdue University, Indianapolis
  • Book:
    Introduction to Biomedical Instrumentation
    Published online:
    06 August 2018
    Print publication:
    07 December 2017, pp 20-29

  • 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.

  • Therapeutic devices generally offer support or treatment to the patient, such as ventilators that provide assisted breathing for patients who cannot breathe on their own.

  • Monitoring devices gather physiological information for clinicians to interpret and utilize for treatment decisions, such as an automated device to measure blood pressure.

  • Some devices are diagnostic, offering information about the patient, such as an X- ray machine producing internal images to identify a broken bone.

    • Medical devices can also be categorized by inherent risk. Highrisk devices are associated with the functions critical to sustaining human life (life support) and can result in serious injury or death to a patient if they malfunction. An example would be an anesthesia machine utilized during surgery. Medium- risk technology is important to patient care but a malfunction is unlikely to cause serious injury. An example of a medium- risk device would be an ultrasound machine, whose images are extremely useful but not critical to patient survival. Lastly, low- risk devices have few consequences related to malfunction other than staff or patient frustration. An infant scale would be an example of a low- risk device.

    Patient Safety and Risk

    Medical care and treatment of patients depends on a balance between benefits and risks. If safety alone is the focus, then the safest approach in healthcare would be to offer no treatment, and utilize no techniques, or technology. This would be safe but not beneficial. In contrast, interventions are integral to healthcare. The HTM profession works to minimize any risks associated with use of technology. Understanding why patients who seek medical interventions are at risk from technology is important to minimizing potential hazards.

  • 7 - The Heart

  • Barbara L. Christe, Indiana University–Purdue University, Indianapolis
  • Book:
    Introduction to Biomedical Instrumentation
    Published online:
    06 August 2018
    Print publication:
    07 December 2017, pp 81-95

  • 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.

  • 2 - Embedded Wireless Device for Intracranial Pressure Monitoring

  • Edited by Isar Mostafanezhad, University of Hawaii, Manoa, Olga Boric-Lubecke, University of Hawaii, Manoa, Jenshan Lin, University of Florida
  • Book:
    Medical and Biological Microwave Sensors and Systems
    Published online:
    14 December 2017
    Print publication:
    07 December 2017, pp 40-88

  • Summary

    Introduction

    Intracranial pressure (ICP) monitoring is a significant tool that aids in the management of neurologic disorders such as hydrocephalus, head trauma, tumors, colloid cysts, and cerebral hematomas. ICP is the pressure exerted on the rigid, bony skull by its constituents, which are brain, cerebrospinal fluid (CSF), and cerebral blood. Increased ICP can lead to brain damage, disability, and death. Various modalities have been developed for monitoring ICP in hospitals and in ambulatory conditions. Currently, only catheter-based systems have made it to clinical practice. The catheter-based systems can only be used in a hospital setting and have a limited useful life owing to drift and the risk of infection. The wired methods of patient monitoring are cumbersome, cause patient discomfort, and can potentially introduce motion artifacts in the measured quantity. The contemporary medical world is witnessing a transition from a wired to a wireless healthcare domain.

    Wireless Technology in Medical Use

    The application of wireless technology in healthcare is becoming ubiquitous, if it is not already so. The therapeutic and diagnostic applications of radiofrequency (RF) and microwave technologies in medicine have been the subject of extensive study in the past [1–3]. Medical implants for the transfer of information at these nonionizing frequencies have been developed [4]. Research accomplishments using data communication links at microwave frequencies between a medical implant and an external unit have been reported by many researchers. The resonance characteristics of implanted antennas operating at a frequency band of 402 to 405 MHz and their radiation pattern outside the body have been shown to be favorable for short-range medical implants [5]. Poon et al. [6] demonstrated that the optimal frequency for power transmission in biologic media is in the gigahertz range. Gosalia et al. [7] demonstrated a novel approach of establishing a data telemetry link between an implant and an external unit in the 1.45 and 2.45 GHz band for retinal prostheses. Such medical implants are basic components for the success of telemedicine, which refers to the use of telecommunication technologies in healthcare. Telemedicine not only facilitates medical treatment and care but is also gaining popularity in posthospital patient care [8]. It provides expert consultation in remote understaffed locations and advanced emergency care via modern telecommunication techniques [9]. Mobile patient monitoring systems using wireless implants have been developed to maintain records of patient vital signs and history [10,11].

  • 4 - Microwave Biosensors for Noninvasive Molecular and Cellular Investigations

  • Edited by Isar Mostafanezhad, University of Hawaii, Manoa, Olga Boric-Lubecke, University of Hawaii, Manoa, Jenshan Lin, University of Florida
  • Book:
    Medical and Biological Microwave Sensors and Systems
    Published online:
    14 December 2017
    Print publication:
    07 December 2017, pp 124-153

  • Summary

    This chapter will give a status on the current possibilities of analysis at the molecular and cellular levels enabled by the convergence of microwave dielectric spectroscopy and the use of microtechnologies. Highlights of the technique will be addressed, such as its noninvasivity, its specificity in terms of high-frequency signature, its compatibility with high ionic and nutrient contents classically encountered with cell culture media, and its suitability and sufficient sensitivity for cell probing, even down to single-cell investigations. These particularities notably will be performed in the context of cancer studies in order to offer complementary noninvasive analyzing tools to the biologists and physicians for living cells in their typical liquid microenvironment.

    Introduction

    There are plenty of physical ways to identify and characterize (bio-)matter physically and/or chemically. Whereas humans exploit their traditional senses (sight, hearing, taste, smell, and touch) to probe the environment, (artificial) sensors – especially biosensors, which are the topic of this chapter – also rely on such sensing mechanisms, for example, mechanical (touch) and optical (sight), but also on other types of interactions, for example, electromagnetic. Such techniques feature a key characteristic: the frequency of the electromagnetic waves can be varied over a range (narrow or broad) to get a rich set of data from spectra, and consequently, the technique is called spectroscopy. Combined with the massive progress in micro- and nanotechnology, miniature biosensors based on dielectric spectroscopy have been in use for several decades, first initiated in direct current (dc) and low frequencies (kilohertz and megahertz) and now reaching microwave and millimeter-wave ranges.

    This chapter aims at showing the status of the current possibilities of analysis at the molecular and cellular levels enabled by the convergence of microwave dielectric spectroscopy and the use of microtechnologies. To understand the interests of developing microwave-based and miniature biosensors for molecular and cellular investigations, examples of the main and current cellular analyzing techniques that are available in biolabs will be given, followed by an introduction to microwave dielectric spectroscopy. Highlights of such a technique will then be addressed in terms of noninvasivity, specificity, compatibility with the high ionic and nutrient contents classically encountered in cell culture media, and suitability and sufficient sensitivity for cell probing, even down to single-cell investigations.

  • 18 - Miscellaneous Devices and Topics

  • Barbara L. Christe, Indiana University–Purdue University, Indianapolis
  • Book:
    Introduction to Biomedical Instrumentation
    Published online:
    06 August 2018
    Print publication:
    07 December 2017, pp 213-224

  • 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.

  • 3 - NFPA and Other Guidelines

  • Barbara L. Christe, Indiana University–Purdue University, Indianapolis
  • Book:
    Introduction to Biomedical Instrumentation
    Published online:
    06 August 2018
    Print publication:
    07 December 2017, pp 30-44

  • 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.

  • 6 - Physiological Radar Sensor Chip Development

  • Edited by Isar Mostafanezhad, University of Hawaii, Manoa, Olga Boric-Lubecke, University of Hawaii, Manoa, Jenshan Lin, University of Florida
  • Book:
    Medical and Biological Microwave Sensors and Systems
    Published online:
    14 December 2017
    Print publication:
    07 December 2017, pp 172-201

  • Summary

    Theory and Recent Advancements

    Using radar to detect small physiologic signals such as respiration and heartbeat dates back to the 1970s [1]. It was realized by detecting the change in carrier phase or the round-trip time of flight (RTOF) in the received radar signals that is caused by the physiologic motion of the human body. The fundamental principle is similar to that in the radar guns that detect the speed of vehicles. Based on the format of transmit signal, there are two basic types of radars: continuous-wave (CW) radar and pulse radar. CW radar falls into two subcategories: single tone, which is mostly operated in interferometry mode, and frequency-modulated CW (FMCW), which sends out a chirp signal with the carrier frequency dynamically changing in time domain. Each category of radar has its specific advantages. Single-tone CW radar has a simple system architecture that allows high-level chip integration. It can also easily achieve high accuracy (submillimeter) in relative displacement measurement. FMCW radar is able to detect the absolute distance between the radar source and the subject, which is referred to as range information. Researchers also have successfully integrated FMCW radar on a chip. Recently, a hybrid radar system combining the advantages of single-tone and FMCW radar was reported by Wang et al. [2]. Pulse radar, which is usually accompanied by ultra-wideband (UWB) characteristics, has very high special resolution due to its large-wideband nature [3]. The integration of UWB radar is also reported for noncontact physiologic sensing.

    A generalized setup of radar noncontact physiologic sensing is shown in Figure 6.1. To detect physiologic signals, the system usually consists of a waveform generator, a radiofrequency (RF) front end, baseband signal conditioning blocks, an analog-to-digital convertor (ADC), and a signal-processing unit. The radar-generated signal is transmitted toward the human subject, where it is modulated by the physiologic motion and partially reflected. The radar receiver captures the received signal, down-converts it into baseband, and sends the digitized signal to the signal-processing unit to extract physiologic motion information, from which important vital signs such as heartbeat, respiration, or even blood pressure can be derived.

    Operation of CW Physiologic-Sensing Radar

    The basic CW radar configuration normally transmits a single-tone RF signal (f 0) toward the human subject, as shown in Figure 6.2. The received signal will maintain the same frequency of f 0, but with a phase shift accumulated along the signal path.

  • 5 - In the Workplace

  • Barbara L. Christe, Indiana University–Purdue University, Indianapolis
  • Book:
    Introduction to Biomedical Instrumentation
    Published online:
    06 August 2018
    Print publication:
    07 December 2017, pp 55-65

  • 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:

  • Use their knowledge, skills, and abilities to enhance the safety, health, and welfare of the public.

  • Strive by action, example, and influence to increase the competence, prestige, and honor of the biomedical engineering profession.

    • Biomedical Engineering Healthcare Obligations

    Biomedical engineers involved in healthcare activities shall:

  • Regard responsibility toward and rights of patients, including those of confidentiality and privacy, as their primary concern.

  • Consider the larger consequences of their work in regard to cost, availability, and delivery of healthcare.

    • A second group has developed an applicable code of ethics. The American College of Clinical Engineering has established the following conventions:

    The American College of Clinical Engineering Code of Ethics

    In the fulfilment of [their] duties, Clinical Engineers will:

  • ■ Hold paramount the safety, health, and welfare of the public.

  • ■ Improve the efficacy and safety of healthcare through the application of technology.

  • ■ Support the efficacy and safety of healthcare through the acquisition and exchange of information and experience with other engineers and managers.

  • ■ Manage healthcare technology programs effectively and resources responsibly.

  • 9 - Blood Pressure

  • Barbara L. Christe, Indiana University–Purdue University, Indianapolis
  • Book:
    Introduction to Biomedical Instrumentation
    Published online:
    06 August 2018
    Print publication:
    07 December 2017, pp 110-118

  • 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.

  • 12 - The Intensive Care Unit

  • Barbara L. Christe, Indiana University–Purdue University, Indianapolis
  • Book:
    Introduction to Biomedical Instrumentation
    Published online:
    06 August 2018
    Print publication:
    07 December 2017, pp 143-157

  • 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:

  • Patients are very ill.

  • Patients have a high mortality rate.

  • Patients may not be conscious or mobile.

  • Most patients are restricted to bed.

  • There are no day/n ight cycles.

  • Physiological monitoring is constant.

  • Each staff member is assigned to only a few patients.

  • Units may be noisy.

  • Patients may be in an ICU for weeks or months.

  • There are restrictions about who can enter a patient room and when.

  • Patients must be monitored very closely.

  • Many tubes may be attached to patients include feeding tubes, endotracheal tubes, intravenous lines, and urinary catheters.

  • Patients may be dependent on a ventilator – a device that uses an endotracheal tube connection to get air into and out of the patient's lungs.

  • Within the ICU, monitoring often consists of

  • The heart's electrical signals, (often with either a three- or five- lead ECG)

  • Non-i nvasive blood pressure using a blood pressure cuff

  • Invasive blood pressure that uses an arterial line (a catheter that enters an artery)

  • 11 - The Brain and its Activity

  • Barbara L. Christe, Indiana University–Purdue University, Indianapolis
  • Book:
    Introduction to Biomedical Instrumentation
    Published online:
    06 August 2018
    Print publication:
    07 December 2017, pp 133-142

  • 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.

  • Neuron – this is the most basic cell associated with the brain. Neurons communicate using electrical energy.

  • Brainstem – this portion of the brain controls life-s ustaining functions.

  • Cerebellum and cerebrum – these major parts of the brain control various body functions and memory.

  • Ventricles of the brain – these spaces within the brain are important because implants and monitors often involve these areas.

  • Spinal cord sections – the spinal cord includes the cervical, thoracic, lumbar, and sacral regions.

  • Cerebral spinal fluid (CSF) – this fluid is very important because it cushions the brain and can be monitored to assess brain health. The fluid circulates around the brain and spinal cord.

    • Electrical Activity in the Brain

    Electroencephalography (or electroencephalogram): The electrical signals from the brain can be measured using many electrodes placed on the scalp. EEG signals created inside the brain are complex and relatively random. Measured at the scalp, EEG amplitudes are very small, in the range of microvolts. Specifically, EEGs are used to

  • Evaluate brain lesions

  • Identify epilepsy

  • Evaluate mental disorders

  • Assess sleep patterns

  • Evaluate brain responses to stimuli

    • Patterns and information are more difficult to obtain from an EEG than from an ECG. In contrast to the patterned electrical activity of the heart, EEG signals may be as unique as a fingerprint. Nevertheless, tests are often performed that evaluate the EEG waveform in response to an input like light or sound as well as to assess patient alertness. Since data can be gathered from many people, a normal EEG response can be predicted and compared to the response of a particular patient. Noise, motion artifacts, and ECG signal interference can present some major issues because EEG waveforms appear at the scalp in such low voltages.

  • 17 - Electronic Medical Record and IT

  • Barbara L. Christe, Indiana University–Purdue University, Indianapolis
  • Book:
    Introduction to Biomedical Instrumentation
    Published online:
    06 August 2018
    Print publication:
    07 December 2017, pp 206-212

  • 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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