Egyptian Biomedical Engineers

HL7 Health Level Seven

noreply@blogger.com (Mohamed Sami) — Tue, 06 May 2008 16:18:00 +0000

BACKGROUND

The term "Level 7" refers to the highest level of the Open System Interconnection (OSI) model of the International Standards Organization (ISO).
Also, HL7 does not specify a set of ISO approved specifications to occupy layers 1 to 6 under HL7's abstract message specifications.
"Health Level Seven standard that enables disparate healthcare applications to exchange keys sets of clinical and administrative data."

NEED FOR A STANDARD

It is not uncommon today for the average hospital to have installed computer systems for admission, discharge, and transfer; clinical laboratories; radiology; billing and accounts receivable, to cite a few. Often these applications have been developed by different vendors or in-house groups, with each product having highly specific information formats.
As hospitals need to share critical data among the systems has emerged.

GOALS OF THE STANDARD

Implemented in the widest variety of technical environments.
Implemented in a wide variety of programming languages and operating systems.
Supported in a wide variety of communications environments.
Immediate transfer of single transactions and multiple transactions.
Supported the process of introducing extensions and new releases into existing operational environments.
Cooperation with other related healthcare standards efforts (e.g., ACR/NEMA DICOM, ASC X12, ASTM, IEEE/MEDIX, NCPDP, etc.) has become a priority activity of HL7.

HL7 encoding rules
Message formats prescribed in the HL7 encoding rules consist of :

data fields that are of variable length
Separated by a field separator character.
Rules describe how the various data types are encoded within a field and when an individual field may be repeated.
The data fields are combined into logical groupings called segments.
Segments are separated by segment separator characters.
Each segment begins with a three-character literal value that identifies it within a message.
Segments may be defined as required or optional and may be permitted to repeat.
Individual data fields are found in the message by their position within their associated segments.

Concept

Trigger event à an event in the real world of healthcare creates and initiates the need for data to flow among systems
Two types of data flow:
- unsolicited update/acknowledgement
- query/result

CONCEPTUAL APPROACH
Trigger events:

The real-world event is called the trigger event. For example: a patient is admitted may cause the need for data about that patient to be sent to a number of other systems.
Transferring of information is initiated by the application system that deals with the triggering event; the transaction is termed an unsolicited update.

Acknowledgments: original mode:

This acknowledgment mode specifies that it be acknowledged at the application level.
It is also necessary to know that the receiving application processed the data successfully at a logical application level

"Acknowledgement" messages can confirm the sender that the message has been received.

Acknowledgments: enhanced mode:

The HL7 acknowledgment has been extended to distinguish both accept and application acknowledgments, as well the conditions under which each are required.
After the message has been processed by the receiving system, an application acknowledgment may be used to return the resultant status to the sending system.

Queries:

A different data exchange occurs when one system sends a query to another.
HL7 queries can be formulated using one of several methods (Select statements, stored procedure, Virtual Table requests, Query Filter via QRD and QRF segments, Event Replay Queries).

If a patient is unknown, e.g., in a laboratory system, an enquiry using an HL7 query can be generated and addressed to the administrative system. The answer contains the missing patient information.

HL7 MESSAGES

A message is the atomic unit of data transferred between systems.
It is comprised of a group of segments in a defined sequence.
Each message has a message type that defines its purpose.
For example the ADT Message type is used for Patient Administration (ADT) data from one system to another. A three-character code contained within each message identifies its type.
The same trigger event code may not be associated with more than one message type; however a message type may be associated with more than one trigger event.

Admit/visit notification - event A01 (admitted patient)
MSH|^~\&|ADT1|MCM|LABADT|MCM|198808181126|ECURITY|ADT^A01|MSG00001|P|2.3|<cr>
EVN|A01|198808181123||<cr>
PID|||PATID1234^5^M11||JONES^WILLIAM^A^III||19610615|M||C|1200 N ELM STREET^^GREENSBORO^NC^27401-1020|GL|(919)379-1212|(919)271-3434||S|| PATID12345001^2^M10|123456789|987654^NC|<cr>
NK1|1|JONES^BARBARA^K|WIFE||||||NK^NEXT OF KIN<cr>
PV1|1|I|2000^2012^01||||004777^LEBAUER^SIDNEY^J.|||SUR||||ADM|A0|<cr>

Patient William A. Jones, III was admitted on July 18, 1988 at 11:23 a.m. by doctor Sidney J.Lebauer (#004777) for surgery (SUR). He has been assigned to room 2012, bed 01 on nursing unit 2000.
The message was sent from system ADT1 at the MCM site to system LABADT, also at the MCM site, on the same date as the admission took place, but three minutes after the admit.

Schematic content of an ADT message with the segments

MSH message header,
EVN description of the trigger events,
PID patient identification,

PV1 patient visit information.

SEGMENTS

A segment is a logical grouping of data fields. Segments of a message may be required or optional.
They may occur only once in a message or they may be allowed to repeat.
Each segment is given a name. For example, the ADT message may contain the following segments: Message Header (MSH), Event Type (EVN), Patient ID (PID), and Patient Visit (PV1).
Each segment is identified by a unique three-character code known as the Segment ID.

FIELDS

A field is a string of characters.
HL7 does not care how systems actually store data within an application.
When fields are transmitted, they are sent as character strings.

Position (sequence within the segment)

Ordinal position of the data field within the segment.
This number is used to refer to the data field in the text comments that follow the segment definition table.
In the segment attribute tables this information is in a column labeled SEQ.

Maximum length

Maximum number of characters that one occurrence of the data field may occupy.
The maximum length is not of conceptual importance in the abstract message or the HL7 coding rules.
The length of a field is normative.

Data type

Restrictions on the contents of the data field.
There are a number of data types defined by HL7.

Optionality

Whether the field is required, optional, or conditional in a segment. The designations are:
R - required
O - optional
C - Conditional on the trigger event or on some other field(s). The field definitions following the segment attribute table should specify the algorithm that defines the conditionality for this field.
X - not used with this trigger event
B - Left in for backward compatibility with previous versions of HL7. The field definitions following the segment attribute table should denote the optionality of the field for prior versions.

Repetition
Whether field may repeat. The designations are:

N - no repetition
Y - the field may repeat an indefinite or site-determined number of times
(integer) - the field may repeat up to the number of times specified in the integer

Extract from the segment table for the PID segment
SEQ : Position (sequence within the segment), LEN: Maximum Length,
DT: Data Type, R/O: Optionality, RP/#: Repetition, TBL#: Table Number
(of referred values), ITEM#: Number of the Item

MESSAGE CONSTRUCTION RULES

Step 1 Construct the segments in the order defined for the message. Each message is constructed as follows:

a) The first three characters are the segment ID code
b) Each data field in sequence is inserted in the segment in the following manner:

a field separator is placed in the segment
if the value is not present, no further characters are required
if the value is present, but null, the characters "" (two consecutive double quotation marks) are placed in the field
Otherwise, place the characters of the value in the segment. As many characters can be included as the maximum defined for the data field. It is not necessary, and is undesirable, to pad fields to fixed lengths. Padding to fixed lengths is permitted. Encode the individual data fields as shown in Section 2.8, "DATA TYPES."
if the field definition calls for a field to be broken into components, the following rules are used:

if more than one component is included they are separated by the component separator
components that are present but null are represented by the characters ""
components that are not present are treated by including no characters in the component
Components that are not present at the end of a field need not be represented by component separators. For example, the two data fields are equivalent: |ABC^DEF^^| and |ABC^DEF|.

if the component definition calls for a component to be broken into subcomponents, the following rules are used:

if more than one subcomponent is included they are separated by the subcomponent separator
subcomponents that are present but null are represented by the characters ""
subcomponents that are not present are treated by including no characters in the subcomponent
Subcomponents that are not present at the end of a component need not be represented by subcomponent separators. For example, the two data components are equivalent: ^XXX&YYY&&^ and ^XXX&YYY^.

if the field definition permits repetition of a field, the following rules are used, the repetition separator is used only if more than one occurrence is transmitted and is placed between occurrences. (If three occurrences are transmitted, two repetition separators are used.) In the example below, two occurrences of telephone number are being sent: |234-7120~599-1288B1234|

c) Repeat Step 1b while there are any fields present to be sent. If all the data fields remaining in the segment definition are not present there is no requirement to include any more delimiters.
d) End each segment with an ASCII carriage return character

Step 2 Repeat Step 1 until all segments have been generated. The following rules apply to receiving HL7 messages and converting their contents to data values:

a) Ignore segments, fields, components, subcomponents, and extra repetitions of a field that are present but were not expected
b) Treat segments that were expected but are not present as consisting entirely of fields that are not present
c) Treat fields and components that are expected but were not included in a segment as not present.

APPLICATION (LEVEL 7) PROCESSING RULES
In overview this exchange proceeds as follows:
Step 1 the initiating system constructs an HL7 message from application data and sends it to the responding system
Step 2 responder receives message and

2.1 when the original acknowledgment rules apply:
- validates the message syntactically and against the detailed rules
- passes the message to the application, which:
  - creates a response message, or
  - creates an error message, or
  - creates a reject message
- Sends the response, error, or reject message Initiator passes the message to the initiating application.
2.2 when enhanced acknowledgment rules apply:
- The responding system receives the message and commits it to safe storage. This means that the responding system accepts the responsibility for the message in a manner that releases the sending system from any obligation to resend the message. The responding system now checks the message header record to determine whether or not the initiating system requires an accept acknowledgment message indicating successful receipt and secure storage of the message. If it does, the accept acknowledgment message is constructed and returned to the initiator.
- At this point, the requirements of the applications involved in the interface determine whether or not more information needs to be exchanged. This exchange is referred to as an application acknowledgment and includes information ranging from simple validation to a complex application-dependent response. If the receiving system is expected to return application-dependent information, it initiates another exchange when this information is available. This time, the roles of initiator and responder are reversed.

QUERIES

Immediate vs. deferred response Responses to queries can be either immediate or deferred.
The query describes this as the expected response time. In the immediate mode, the responding process gives the response immediately or in a short period during which the requesting process will wait for the response.

QUERY TRIGGER EVENTS AND MESSAGE DEFINITIONS

These are the trigger event types associated with queries:

a need occurs for immediate access to data that may be available from another application, this may be an initial request for data or a continuation
a need occurs for deferred access to data that may be available from another application

Where an original-style query is involved, these trigger events are served by the query message (QRY). When display data is involved, these trigger events are served by the Query (QRY) and Display Response (DSR) and General Acknowledgment (ACK) messages. When the query is for record-oriented data, the QRY message is used, but the response message is specific to a functional area. Record-oriented queries are described in detail in the relevant application chapters. Display-oriented responses are described in detail in this chapter.

Nature of the Work

noreply@blogger.com (Mohamed Sami) — Tue, 06 May 2008 15:38:00 +0000

By combining biology and medicine with engineering, biomedical engineers develop devices and procedures that solve medical and health-related problems. Many do research, along with life scientists, chemists, and medical scientists, to develop and evaluate systems and products for use in the fields of biology and health, such as artificial organs, prostheses (artificial devices that replace missing body parts), instrumentation, medical information systems, and health management and care delivery systems. Biomedical engineers design devices used in various medical procedures, such as the computers used to analyze blood or the laser systems used in corrective eye surgery. They develop artificial organs, imaging systems such as magnetic resonance, ultrasound, and x-ray, and devices for automating insulin injections or controlling body functions. Most engineers in this specialty require a sound background in one of the basic engineering specialties, such as mechanical or electronics engineering, in addition to specialized biomedical training. Some specialties within biomedical engineering include biomaterials, biomechanics, medical imaging, rehabilitation engineering, and orthopedic engineering.

Unlike many other engineering specialties, a graduate degree is recommended or required for many entry-level jobs.

Employment

Biomedical engineers held about 7,600 jobs in 2002. Manufacturing industries employed 38 percent of all biomedical engineers, primarily in the pharmaceutical and medicine manufacturing and medical instruments and supplies industries. Many others worked for hospitals. Some also worked for government agencies or as independent consultants.

Job Outlook

Employment of biomedical engineers is expected to faster than the average for all occupations through 2012. The aging of the population and the focus on health issues will increase the demand for better medical devices and equipment designed by biomedical engineers. For example, computer-assisted surgery and molecular, cellular, and tissue engineering are being more heavily researched and are developing rapidly. In addition, the rehabilitation and orthopedic engineering specialties are growing quickly, increasing the need for biomedical engineers. Along with the demand for more sophisticated medical equipment and procedures is an increased concern for cost efficiency and effectiveness that also will boost demand for biomedical engineers. However, because of the growing interest in this field, the number of degrees granted in biomedical engineering has increased greatly, leading to the potential for competition for jobs.

Earnings

Median annual earnings of biomedical engineers were $60,410 in 2002. The middle 50 percent earned between $58,320 and $88,830. The lowest 10 percent earned less than $48,450, and the highest 10 percent earned more than $107,520. According to a 2003 salary survey by the National Association of Colleges and Employers, bachelor degree candidates in biomedical engineering received starting offers averaging $39,126 a year, and master degree candidates, on average, were offered $61,000.

Sources of Additional Information

For further information about biomedical engineers, contact:

Biomedical Engineering Society, 8401 Corporate Dr., Suite 225, Landover, MD 20785-2224. Internet: http://www.bmes.org

A History of Biomedical Engineering.

noreply@blogger.com (Mohamed Sami) — Sat, 03 May 2008 13:03:00 +0000

In its broadest sense, biomedical engineering has been with us for centuries, perhaps even thousands of years. In 2000, German archeologists uncovered a 3,000-year-old mummy from Thebes with a wooden prosthetic tied to its foot to serve as a big toe. Researchers said the wear on the bottom surface suggests that it could be the oldest known limb prosthesis. Egyptians also used hollow reeds to look and listen to the internal goings on of the human anatomy. In 1816, modesty prevented French physician Rene Laennec from placing his ear next to a young woman’s bare chest, so he rolled up a newspaper and listened through it, triggering the idea for his invention that led to today’s ubiquitous stethoscope.

No matter what the date, biomedical engineering has provided advances in medical technology to improve human health. Biomedical engineering achievements range from early devices, such as crutches, platform shoes, wooden teeth, and the ever-changing cache of instruments in a doctor’s black bag, to more modern marvels, including pacemakers, the heart-lung machine, dialysis machines, diagnostic equipment, imaging technologies of every kind, and artificial organs, implants and advanced prosthetics. The National Academy of Engineering estimates that there are currently about 32,000 bioengineers working in various areas of health technology.

As an academic endeavor, the roots of biomedical engineering reach back to early developments in electrophysiology, which originated about 200 years ago. An early landmark in electrophysiology occurred in 1848 when DuBois Reymond published the widely recognized Ueber die tierische Elektrizitaet. Raymond’s contemporary, Hermann von Helmholtz, is credited with applying engineering principles to a problem in physiology and identifying the resistance of muscle and nervous tissues to direct current.

In 1895, Wilhelm Roentgen accidentally discovered that a cathode-ray tube could make a sheet of paper coated with barium platinocyanide glow, even when the tube and the paper were in separate rooms. Roentgen decided the tube must be emitting some kind of penetrating rays, which he called “X” rays for unknown. This set off a flurry of research into the tissue-penetrating and tissue-destroying properties of X-rays, a line of research that ultimately produced the modern array of medical imaging technologies and virtually eliminated the need for exploratory surgery.

Biomedical engineering’s unique mix of engineering, medicine and science emerged alongside biophysics and medical physics early this century. At the outset, the three were virtually indistinguishable and none had formal training programs.

Between World War I and World War II a number of laboratories undertook research in biophysics and biomedical engineering. Only one offered formal training: the Oswalt Institute for Physics in Medicine, established in 1921 in Frankfurt, Germany, forerunner of the Max Planck Institute fur Biophysik.

The Institute’s founder, Friedrich Dessauer, pioneered research into the biological effects of ionizing radiation. The Oswalt Institute and the University in Frankfurt soon established formal ties that led to a Ph.D. program in biophysics by 1940. Research topics included the effects of X-rays on tissues and the electrical properties of tissues. The staff of 20 included university lecturers, research fellows, assistants and technicians.

Following the Second World War, administrative committees began forming around the combined areas of engineering, medicine and biology. A biophysical society was formed in Germany in 1943. Five years later, the first conference of engineering in medicine and biology convened in the United States, under the auspices of the Institute of Radio Engineers (forerunner of the Institute of Electrical and Electronics Engineers), the American Institute for Electrical Engineering, and the Instrument Society of America. It was a small meeting. About 20 papers were delivered to an audience of fewer than 100. The first 10 annual conferences paid most of their attention to ionizing radiation and its implications. As conference topics broadened, so did attendance. The topic of the 1958 conference, Computers in Medicine and Biology, drew 70 papers and more than 300 attendees. By 1961, conference attendance swelled to nearly 3,000.

The 1951 IRE convention generated enough interest in medical electronics that the IRE formed a Professional Group on Medical Electronics. An early action of this group was to collaborate on the Annual Conference on Electronic Instrumentation and Nucleonics in Medicine, which the AIEE began about 1948. In 1954, the AIEE, the IRE and the ISA formed the Joint Executive Committee on Medicine and Biology, which began organizing the annual conferences.

In 1963, the AIEE and the IRE merged to form the Institute of Electrical and Electronics Engineering. Contributing forces for the merger were the members of the AIEE and IRE technical committees for biomedical engineering. Most members favored it and had been collaborating with their counterparts in the other society for years.

At the merger it was decided to carry over to the IEEE the IRE system of Professional Groups. The IRE Professional Group on Medical Electronics became the IEEE Professional Group on Bio-Medical Engineering (PGBME), the name change reflecting the fact that many members, particularly former AIEE members, were concerned with non-electronic topics.

Also in the early 1960s the NIH took three significant steps to support biomedical engineering. First, it created a program-project committee under the General Medical Sciences Institute to evaluate program-project applications, many of which served biophysics and biomedical engineering. Then it set up a biomedical engineering training study section to evaluate training-grant applications, and it established two biophysics study sections. A special “floating” study section processed applications in bioacoustics and biomedical engineering. Many applications did not make it to the biomedical engineering study section and ended up in radiology, physiology or other panels.

The diversity of work in biomedical engineering and the diversity of background of the people contributing to this field made it difficult for a single organization to represent everyone. In the 1960s there were efforts by some leaders of the PGBME, which became the IEEE Engineering in Medicine and Biology Society, to achieve greater autonomy within the IEEE in order to accommodate a more diverse membership. Because there were quite a few professional groups, several umbrella organizations were established to facilitate cooperation. In the late 1960s the Alliance for Engineering in Medicine and Biology was formed. In 1968, the Biomedical Engineering Society was formed to give “equal status to representatives of both biomedical and engineering interests and promote the increase of biomedical engineering knowledge and its utilization.” Initially, the membership of the society consisted of 171 founding members and 89 charter members. Membership now numbers nearly 1,200 professional biomedical engineers, with another 1,600 student members.

The society awarded the Alza Distinguished Lectureship from 1971 to 1993 to encourage the theory and practice of biomedical engineering. The BMES Distinguished Lectureship Award was founded in 1991 to recognize outstanding achievements in biomedical engineering. Other honors include a young investigator award, the BMES Distinguished Service Award, and the Presidential Award, established in 1999 to enable BMES presidents to recognize extraordinary leadership within the society.

In addition to the professional societies, the field of biomedical engineering received a large ally when The Whitaker Foundation was created in 1975, upon the death of U.A. Whitaker. As an engineer and philanthropist, Whitaker recognized that major contributions to improving human health would come from the merging of medicine and engineering. Since its inception, the foundation has primarily supported interdisciplinary medical research and education, with the principal focus being on biomedical engineering. The foundation has become the nation’s largest private benefactor of biomedical engineering. By 2002, it had contributed more than $615 million to universities and medical schools to support faculty research, graduate students, program development, and construction of facilities.

In 1990 the National Science Foundation and The Whitaker Foundation observed that in spite of the numerous academic programs calling themselves “bioengineering” or “biomedical engineering,” there was no structure for this widely diversified field. Because many advances in biomedical engineering were generated through the collaboration of engineers and clinical scientists in a number of different fields, the evolution of biomedical engineering as a profession in the 1970s and 1980s was characterized by the emergence of separate professional societies with a focus on applications within their own field.

As a step toward unification, the American Institute for Medical and Biological Engineering was created in 1992. AIMBE was born from the realization that an umbrella organization was needed to address the issues of public policy and public and professional education that comprise these engineering sciences. Ten societies saw the virtue of this approach and formed the original members of AIMBE. Today, its 17 society members work to “establish a clear and comprehensive identity for the field of medical and biological engineering, and improve intersociety relations and cooperation within the field of medical and biological engineering.”

The earliest academic programs began to take shape in the 1950s. Their establishment was aided by Sam Talbot of Johns Hopkins University, who petitioned the National Institutes of Health for funding to support a group discussion of approaches to teaching biomedical engineering. Ultimately three universities were represented in these discussions: The Johns Hopkins University, the University of Pennsylvania and the University of Rochester. These three institutions, along with Drexel University, were among the first to win important training grants for biomedical engineering from the National Institutes of Health.

In 1973, discussions started about broadening the base of Pennsylvania’s graduate Department of Biomedical Electronic Engineering by including other activities and adopting and undergraduate curriculum. Its present graduate program is an extension of the earlier one.

During the late 1960s and early 1970s, development at other institutions followed similar paths, but occurred more rapidly in most cases due to the growing opportunities of the field and in response to the important NIH initiative to support the development of the field. The earlier institutions were soon followed by a second generation of biomedical engineering programs and departments. These included: Boston University in 1966; Case Western Reserve University in 1968; Northwestern University in 1969; Carnegie Mellon, Duke University, Renssselaer and a joint program between Harvard and MIT in 1970; Ohio State University and University of Texas, Austin, in 1971; Louisiana Tech, Texas A&M and the Milwaukee School of Engineering in 1972; and the University of Illinois, Chicago in 1973.

The number of departments and programs continued to rise slowly but steadily in the 1980s and early 1990s. In 1992, The Whitaker Foundation initiated large grant programs designed to help institutions establish or develop biomedical engineering departments or programs. Since then, the numbers of departments and programs have risen to more than 90. Some of the largest and most prominent engineering institutions in the country, such as the Georgia Institute of Technology, have established programs and emerged as leaders in the field. Many other new and existing programs have benefited from the foundation’s support.

A major development took place in late 2000 when President Clinton signed a bill creating the National Institute of Biomedical Imaging and Bioengineering at the NIH. According to NIBIB’s website, its mission is to "improve health by promoting fundamental discoveries, design and development, and translation and assessment of technological capabilities. The Institute coordinates with biomedical imaging and bioengineering programs of other agencies and NIH institutes to support imaging and engineering research with potential medical applications and facilitates the transfer of such technologies to medical applications."

The newest of the NIH institutes, NIBIB spent much of 2001 building program and administrative staff, preparing a budget request, setting up office space, determining funding and grant identification codes and procedures, and identifying program (research, training, and communication) focus areas and opportunities. NIBIB assumed administration of the NIH's Bioengineering Consortium (BECON) in September 2001, and awarded its first research grant in April 2002.

Additional resources:
The Biomedical Engineering Society

What is a Biomedical Engineer?

noreply@blogger.com (Mohamed Sami) — Sat, 03 May 2008 13:01:00 +0000

A Biomedical Engineer uses traditional engineering expertise to analyze and solve problems in biology and medicine, providing an overall enhancement of health care. Students choose the biomedical engineering field to be of service to people, to partake of the excitement of working with living systems, and to apply advanced technology to the complex problems of medical care. The biomedical engineer works with other health care professionals including physicians, nurses, therapists and technicians. Biomedical engineers may be called upon in a wide range of capacities: to design instruments, devices, and software, to bring together knowledge from many technical sources to develop new procedures, or to conduct research needed to solve clinical problems.

Biomedical Engineering Society, 2003

What is Biomedical Engineering?

noreply@blogger.com (Mohamed Sami) — Sat, 03 May 2008 12:35:00 +0000

Biomedical engineering is the application of engineering techniques and analyses to problem-solving in medicine and the biomedical sciences.In most aspects of health care, disease prevention, and treatment, or rehabilitation, there are problems that require an engineering approach. These may include developing systems to maintain and enhance life, designing replacement parts for people, or creating systems to allow the handicapped to use computers for work and communication.The growing complexity of medical technology has increased the demand for appropriately trained professionals to bridge the gap between clinical medicine and applied medical technology. This personnel must be capable of defining a medical problem in engineering science terms and of finding a solution that satisfies both engineering and medical requirements. Such trained personnel constitute the core of biomedical engineers.The biomedical engineer has expertise in engineering science, biological science, and medical science. Biomedical engineering is usually based on one of the traditional engineering disciplines, such as electrical or mechanical engineering. There has been a great expansion of biomedical engineering in areas such as medical electronics, clinical engineering, biomaterials, and rehabilitation engineering. The scope of the field is enormous: from cardiac monitors to clinical computing, artificial hearts to contact lenses, wheelchairs to artificial tendons, modeling dialysis therapy to modeling the cardiovascular system. Biomedical engineers are also integral in the management of technology in hospitals and health care delivery.