Artificial organ
Encyclopedia
An artificial organ is a man-made device that is implanted or integrated into a human to replace a natural organ
Organ (anatomy)
In biology, an organ is a collection of tissues joined in structural unit to serve a common function. Usually there is a main tissue and sporadic tissues . The main tissue is the one that is unique for the specific organ. For example, main tissue in the heart is the myocardium, while sporadic are...

, for the purpose of restoring a specific function or a group of related functions so the patient may return to as normal a life as possible. The replaced function doesn't necessarily have to be related to life support
Life support
Life support, in medicine is a broad term that applies to any therapy used to sustain a patient's life while they are critically ill or injured. There are many therapies and techniques that may be used by clinicians to achieve the goal of sustaining life...

, but often is.

Implied by this definition is the fact that the device must not be continuously tethered to a stationary power supply, or other stationary resources, such as filters or chemical processing units. (Periodic rapid recharging of batteries, refilling of chemicals, and/or cleaning/replacing of filters, would exclude a device from being called an artificial organ.) Thus a dialysis
Dialysis
In medicine, dialysis is a process for removing waste and excess water from the blood, and is primarily used to provide an artificial replacement for lost kidney function in people with renal failure...

 machine, while a very successful and critically important life support device that completely replaces the duties of a kidney
Kidney
The kidneys, organs with several functions, serve essential regulatory roles in most animals, including vertebrates and some invertebrates. They are essential in the urinary system and also serve homeostatic functions such as the regulation of electrolytes, maintenance of acid–base balance, and...

, is not an artificial organ. At this time an efficient, self-contained artificial kidney
Artificial kidney
Artificial kidney is often a synonym for hemodialysis, but may also, more generally, refer to renal replacement therapies that are in use and/or in development...

 has not become available.
construct and install an artificial organ, an extremely expensive process initially, which may entail many years of ongoing maintenance services not needed by a natural organ, might include:
  • Life support to prevent imminent death while awaiting a transplant
    Organ transplant
    Organ transplantation is the moving of an organ from one body to another or from a donor site on the patient's own body, for the purpose of replacing the recipient's damaged or absent organ. The emerging field of regenerative medicine is allowing scientists and engineers to create organs to be...

     (e.g. artificial heart
    Artificial heart
    An artificial heart is a mechanical device that replaces the heart. Artificial hearts are typically used in order to bridge the time to heart transplantation, or to permanently replace the heart in case transplantation is impossible...

    )
  • Dramatic improvement of the patient's ability for self care (e.g. artificial limb
    Prosthesis
    In medicine, a prosthesis, prosthetic, or prosthetic limb is an artificial device extension that replaces a missing body part. It is part of the field of biomechatronics, the science of using mechanical devices with human muscle, skeleton, and nervous systems to assist or enhance motor control...

    )
  • Improvement of the patient's ability to interact socially (e.g. cochlear implant
    Cochlear implant
    A cochlear implant is a surgically implanted electronic device that provides a sense of sound to a person who is profoundly deaf or severely hard of hearing...

    )
  • Cosmetic restoration
    Plastic surgery
    Plastic surgery is a medical specialty concerned with the correction or restoration of form and function. Though cosmetic or aesthetic surgery is the best-known kind of plastic surgery, most plastic surgery is not cosmetic: plastic surgery includes many types of reconstructive surgery, hand...

     after cancer surgery
    Surgical oncology
    Surgical oncology is the branch of surgery which focuses on the surgical management of cancer.The specialty of surgical oncology has evolved in steps similar to medical oncology, which grew out of hematology, and radiation oncology, which grew out of radiology...

     or accident


The use of any artificial organ by humans is almost always preceded by extensive experiments with animals
Animal testing
Animal testing, also known as animal experimentation, animal research, and in vivo testing, is the use of non-human animals in experiments. Worldwide it is estimated that the number of vertebrate animals—from zebrafish to non-human primates—ranges from the tens of millions to more than 100 million...

. Initial testing in humans is frequently limited to those either already facing death, or who have exhausted every other treatment possibility. (Rarely testing may be done on healthy volunteers who are scheduled for execution pertaining to violent crime
Violent crime
A violent crime or crime of violence is a crime in which the offender uses or threatens to use violent force upon the victim. This entails both crimes in which the violent act is the objective, such as murder, as well as crimes in which violence is the means to an end, such as robbery. Violent...

s.)

Although not typically thought of as organs, one might also consider replacement bone, and joints thereof, such as hip replacement
Hip replacement
Hip replacement is a surgical procedure in which the hip joint is replaced by a prosthetic implant. Hip replacement surgery can be performed as a total replacement or a hemi replacement. Such joint replacement orthopaedic surgery generally is conducted to relieve arthritis pain or fix severe...

s, in this context.

Brain

Brain pacemaker
Brain pacemaker
"Brain pacemakers" are used to treat people who suffer from epilepsy, Parkinson's disease, major depression and other diseases. The pacemaker is a medical device that is implanted into the brain to send electrical signals into the tissue. Depending on the area of the brain that is targeted, the...

s, including deep brain stimulator
Deep brain stimulation
Deep brain stimulation is a surgical treatment involving the implantation of a medical device called a brain pacemaker, which sends electrical impulses to specific parts of the brain...

s, send electrical impulses to the brain in order to relieve depression
Clinical depression
Major depressive disorder is a mental disorder characterized by an all-encompassing low mood accompanied by low self-esteem, and by loss of interest or pleasure in normally enjoyable activities...

, epilepsy
Epilepsy
Epilepsy is a common chronic neurological disorder characterized by seizures. These seizures are transient signs and/or symptoms of abnormal, excessive or hypersynchronous neuronal activity in the brain.About 50 million people worldwide have epilepsy, and nearly two out of every three new cases...

, tremor
Tremor
A tremor is an involuntary, somewhat rhythmic, muscle contraction and relaxation involving to-and-fro movements of one or more body parts. It is the most common of all involuntary movements and can affect the hands, arms, eyes, face, head, vocal folds, trunk, and legs. Most tremors occur in the...

s of Parkinson's disease
Parkinson's disease
Parkinson's disease is a degenerative disorder of the central nervous system...

, and other conditions such as increased bladder secretions. Rather than replacing existing neural network
Biological neural network
In neuroscience, a biological neural network describes a population of physically interconnected neurons or a group of disparate neurons whose inputs or signalling targets define a recognizable circuit. Communication between neurons often involves an electrochemical process...

s to restore function, these devices often serve by disrupting the output of existing malfunctioning nerve centers to eliminate symptoms.

Cardia and pylorus valves

Artificial cardia
Cardia
The cardia is the anatomical term for the part of the stomach attached to the esophagus. The cardia begins immediately distal to the z-line of the gastroesophageal junction, where the squamous epithelium of the esophagus gives way to the columnar epithelium of the gastrointestinal tract.Just...

 and pylorus
Pylorus
The pylorus is the region of the stomach that connects to the duodenum . It is divided into two parts:* the pyloric antrum, which connects to the body of the stomach.* the pyloric canal, which connects to the duodenum....

 can be used to fight esophageal cancer
Esophageal cancer
Esophageal cancer is malignancy of the esophagus. There are various subtypes, primarily squamous cell cancer and adenocarcinoma . Squamous cell cancer arises from the cells that line the upper part of the esophagus...

, achalasia
Achalasia
Achalasia , also known as esophageal achalasia, achalasia cardiae, cardiospasm, and esophageal aperistalsis, is an esophageal motility disorder involving the smooth muscle layer of the esophagus and the lower esophageal sphincter...

 and gastroesophageal reflux disease
Gastroesophageal reflux disease
Gastroesophageal reflux disease , gastro-oesophageal reflux disease , gastric reflux disease, or acid reflux disease is chronic symptoms or mucosal damage caused by stomach acid coming up from the stomach into the esophagus...

. This pertains to gastric repairs, specifically of the valve
Valve
A valve is a device that regulates, directs or controls the flow of a fluid by opening, closing, or partially obstructing various passageways. Valves are technically pipe fittings, but are usually discussed as a separate category...

s at either end of the stomach
Stomach
The stomach is a muscular, hollow, dilated part of the alimentary canal which functions as an important organ of the digestive tract in some animals, including vertebrates, echinoderms, insects , and molluscs. It is involved in the second phase of digestion, following mastication .The stomach is...

.

Corpora cavernosa

To treat erectile disfunction, both corpora cavernosa
Corpus cavernosum penis
The corpus cavernosum penis is one of a pair of sponge-like regions of erectile tissue which contain most of the blood in the penis during penile erection...

 can be irreversibly surgically replaced with manually inflatable penile implants. This is a drastic therapeutic surgery meant only for men suffering from complete impotence that has resisted all other treatment approaches. An implanted pump in the (groin) or (scrotum) can be manipulated by hand to fill these artificial cylinders, normally sized to be direct replacements for the natural corpus cavernosa, from an implanted reservoir in order to achieve an erection.

Ear

While natural hearing, to the level of musical quality, is not typically achieved, most recipients are pleased, with some finding it useful enough to return to their surgeon with a request to do the other ear.

Eye

The most successful function-replacing artificial eye so far is actually an external miniature digital camera
Digital camera
A digital camera is a camera that takes video or still photographs, or both, digitally by recording images via an electronic image sensor. It is the main device used in the field of digital photography...

 with a remote unidirectional electronic
Electronics
Electronics is the branch of science, engineering and technology that deals with electrical circuits involving active electrical components such as vacuum tubes, transistors, diodes and integrated circuits, and associated passive interconnection technologies...

 interface implanted on the retina
Retina
The vertebrate retina is a light-sensitive tissue lining the inner surface of the eye. The optics of the eye create an image of the visual world on the retina, which serves much the same function as the film in a camera. Light striking the retina initiates a cascade of chemical and electrical...

, optic nerve
Optic nerve
The optic nerve, also called cranial nerve 2, transmits visual information from the retina to the brain. Derived from the embryonic retinal ganglion cell, a diverticulum located in the diencephalon, the optic nerve doesn't regenerate after transection.-Anatomy:The optic nerve is the second of...

, or other related locations inside the brain
Brain
The brain is the center of the nervous system in all vertebrate and most invertebrate animals—only a few primitive invertebrates such as sponges, jellyfish, sea squirts and starfishes do not have one. It is located in the head, usually close to primary sensory apparatus such as vision, hearing,...

. The present state of the art yields only very partial functionality, such as recognizing levels of brightness, swatches of color, and/or basic geometric shapes, proving the concept's potential. While the living eye is indeed a camera, it is also much more than that.

Various researchers have demonstrated that the retina performs strategic image
Image
An image is an artifact, for example a two-dimensional picture, that has a similar appearance to some subject—usually a physical object or a person.-Characteristics:...

 preprocessing for the brain. The problem of creating a 100% functional artificial electronic eye is even more complex than what is already obvious. Steadily increasing complexity of the artificial connection to the retina, optic nerve or related brain areas advances, combined with ongoing advances in computer science
Computer science
Computer science or computing science is the study of the theoretical foundations of information and computation and of practical techniques for their implementation and application in computer systems...

, is expected to dramatically improve the performance of this technology.

For the person whose damaged or diseased living eye retains some function, other options superior to the electronic eye may be available.

Heart

While considered a success, the use of artificial heart
Artificial heart
An artificial heart is a mechanical device that replaces the heart. Artificial hearts are typically used in order to bridge the time to heart transplantation, or to permanently replace the heart in case transplantation is impossible...

s is limited to patients awaiting transplants whose death is imminent. The current state of the art devices are unable to reliably sustain life beyond about 18 months.

Artificial pacemaker
Artificial pacemaker
A pacemaker is a medical device that uses electrical impulses, delivered by electrodes contacting the heart muscles, to regulate the beating of the heart...

s are electronic
Electronics
Electronics is the branch of science, engineering and technology that deals with electrical circuits involving active electrical components such as vacuum tubes, transistors, diodes and integrated circuits, and associated passive interconnection technologies...

 devices which can either intermittently augment (defibrillator mode), continuously augment, or completely bypass the natural living cardiac pacemaker
Cardiac pacemaker
right|thumb|350px|Image showing the cardiac pacemaker which is the SA nodeThe contraction of heart muscle in all animals with hearts is initiated by chemical impulses. The rate at which these impulses fire controls the heart rate...

 as needed, are so successful that they have become commonplace.

Ventricular assist device
Ventricular assist device
A Ventricular assist device, or VAD, is a mechanical circulatory device that is used to partially or completely replace the function of a failing heart...

s are mechanical circulatory devices that partially or completely replace the function of a failing heart, without the removal of the heart itself.

Limbs

Artificial arms with semi-functional hands, some even fitted with working opposable "thumbs"
Thumb
The thumb is the first digit of the hand. When a person is standing in the medical anatomical position , the thumb is the lateral-most digit...

 plus 2 "fingers", and legs with shock absorbing feet capable of allowing a trained patient to even run, have become available. While the meaning of "full mobility" is debated, steady progress is made.

Liver

HepaLife is developing a bioartificial liver
Liver
The liver is a vital organ present in vertebrates and some other animals. It has a wide range of functions, including detoxification, protein synthesis, and production of biochemicals necessary for digestion...

 device intended for the treatment of liver failure using stem cell
Stem cell
This article is about the cell type. For the medical therapy, see Stem Cell TreatmentsStem cells are biological cells found in all multicellular organisms, that can divide and differentiate into diverse specialized cell types and can self-renew to produce more stem cells...

s. The artificial liver, currently under development, is designed to serve as a supportive device, either allowing the liver to regenerate upon acute liver failure, or to bridge the patient's liver functions until a transplant is available. It is only made possible by the fact that it uses real liver cells (hepatocytes), and even then, it is not a permanent substitute for a liver.

On the other hand, Researchers Dr. Colin McGucklin, Professor of Regenerative Medicine
Regenerative medicine
Regenerative medicine is the "process of replacing or regenerating human cells, tissues or organs to restore orestablish normal function". This field holds the promise of regenerating damaged tissues and organs in the body by replacing damaged tissue and/or by stimulating the body's own repair...

 at Newcastle University, and Dr. Nico Forraz, Senior Research Associate and Clinical Sciences Business Manager at Newcastle University, say that pieces of artificial liver could be used to repair livers injured in the next five years. These artificial livers could also be used outside the body in a manner analogous to the dialysis
Dialysis
In medicine, dialysis is a process for removing waste and excess water from the blood, and is primarily used to provide an artificial replacement for lost kidney function in people with renal failure...

 process used to keep alive patients whose kidneys have failed.

Lungs

With some almost fully functional, artificial lung
Artificial lung
An artificial lung is a prosthetic device that is implanted into the body to replace the biological lung. It is different from a heart-lung machine in that it is internal and designed to take over the functions of the lungs for long periods of time rather than on a temporary basis.Recent...

s promise to be a great success in near future. An Ann Arbor company MC3 is currently working on this type of medical device.

Pancreas

For the treatment of diabetes, numerous promising techniques are currently being developed, including some that incorporate donated living tissue housed in special materials to prevent the patient's immune system from killing the foreign live components.

Bladder

Artificial bladders represent a unique success in that these are autologous laboratory-grown living replacements, as opposed to most other artificial organs which depend upon electro-mechanical contrivances, and may or may not incorporate any living tissue.

Ovaries

Reproductive age patients who develop cancer often receive chemotherapy or radiation therapy which damages oocytes and leads to early menopause. An artificial human ovary has been developed at Brown University with self-assembled microtissues created using novel 3-D petri dish technology. The artificial ovary will be used for the purpose of in vitro maturation of immature oocytes and the development of a system to study the effect of environmental toxins on folliculogenesis.

Trachea

Surgeons in Sweden performed the first implantation of a synthetic trachea in July 2011, for a 36-year-old patient who was suffering from cancer. Stem cells taken from the patient's hip were treated with growth factors and incubated on a plastic replica of his natural trachea.

Beyond restoration

It is also possible to construct and install an artificial organ to give its possessor abilities which are not naturally occurring. Research is proceeding, particularly in areas of vision
Visual perception
Visual perception is the ability to interpret information and surroundings from the effects of visible light reaching the eye. The resulting perception is also known as eyesight, sight, or vision...

, memory
Memory
In psychology, memory is an organism's ability to store, retain, and recall information and experiences. Traditional studies of memory began in the fields of philosophy, including techniques of artificially enhancing memory....

, and information processing
Information processing
Information processing is the change of information in any manner detectable by an observer. As such, it is a process which describes everything which happens in the universe, from the falling of a rock to the printing of a text file from a digital computer system...

, however this idea is still in its infancy.

Some current research
Research
Research can be defined as the scientific search for knowledge, or as any systematic investigation, to establish novel facts, solve new or existing problems, prove new ideas, or develop new theories, usually using a scientific method...

 focuses on restoring inoperative short-term memory
Short-term memory
Short-term memory is the capacity for holding a small amount of information in mind in an active, readily available state for a short period of time. The duration of short-term memory is believed to be in the order of seconds. A commonly cited capacity is 7 ± 2 elements...

 in accident victims and lost access to long-term memory
Long-term memory
Long-term memory is memory in which associations among items are stored, as part of the theory of a dual-store memory model. According to the theory, long term memory differs structurally and functionally from working memory or short-term memory, which ostensibly stores items for only around 20–30...

 in dementia
Dementia
Dementia is a serious loss of cognitive ability in a previously unimpaired person, beyond what might be expected from normal aging...

 patients. Success here would lead to widespread interest in applications for persons whose memory is considered healthy to dramatically enhance their memory of far beyond what can be achieved with mnemonic
Mnemonic
A mnemonic , or mnemonic device, is any learning technique that aids memory. To improve long term memory, mnemonic systems are used to make memorization easier. Commonly encountered mnemonics are often verbal, such as a very short poem or a special word used to help a person remember something,...

 techniques. Given that our understanding of how living memory actually works is incomplete, it is unlikely this scenario will become reality in the near future.

One area of success was achieved in 2002 when a British Scientist, Kevin Warwick
Kevin Warwick
Kevin Warwick is a British scientist and professor of cybernetics at the University of Reading, Reading, Berkshire, United Kingdom...

, had an array of 100 electrodes fired into his nervous system in order to link his nervous system into the internet. With this in place he carried out a series of experiments including extending his nervous system over the internet to control a robotic hand, a form of extended sensory input and the first direct electronic communication between the nervous systems of two humans.

Another idea with significant consequences is that of implanting a Language Translator
Translation
Translation is the communication of the meaning of a source-language text by means of an equivalent target-language text. Whereas interpreting undoubtedly antedates writing, translation began only after the appearance of written literature; there exist partial translations of the Sumerian Epic of...

 for diplomatic and military applications. While machine translation
Machine translation
Machine translation, sometimes referred to by the abbreviation MT is a sub-field of computational linguistics that investigates the use of computer software to translate text or speech from one natural language to another.On a basic...

 does exist, it is presently neither good nor small enough to fulfill its promise.

This might also include the existing (and controversial when applied to humans) practice of implanting subcutaneous "chips" (integrated circuits) for identification and location purposes. An example of this is the RFID tags made by VeriChip Corporation.

More information

(BBC)Official Peer-Reviewed Journal of the International Federation for Artificial Organs (members of the Federation are: the American Society for Artificial Internal Organs, the European Society for Artificial Organs and the Japanese Society for Artificial Organs), the International Faculty for Artificial Organs, and the International Society for Rotary Blood Pumps.

Edited by: Paul S. Malchesky, D. Eng.

ISI Journal Citation Reports Ranking: 2009: Transplantation: 15 / 24; Engineering, Biomedical: 27 / 59 Impact Factor: 1.827

Since 1977, Artificial Organs has been publishing original articles featuring the studies of design, performance, and evaluation of the biomaterials and devices for the international medical, scientific, and engineering communities involved in the research and clinical application of artificial organ development. Artificial Organs, published monthly, brings its readership the depth and breadth of the science and technology that continues to advance the Replacement, Recovery and Regeneration of organ systems.

See also

  • Artificial bone
    Artificial bone
    Artificial bone refers to bone-like material created in a laboratory that can be used in bone grafts, to replace human bone that was lost due to severe fractures, disease, etc.-Overview:...

  • Artificial skin
    Artificial skin
    Artificial skin can refer to skin grown in a laboratory that can be used as skin replacement for people who have suffered skin trauma such as severe burns or skin diseases.Alternatively, it can also refer to skin synthetically produced for other purposes....

  • Bionics
    Bionics
    Bionics is the application of biological methods and systems found in nature to the study and design of engineering systems and modern technology.The word bionic was coined by Jack E...

  • Biomedical Engineering
    Biomedical engineering
    Biomedical Engineering is the application of engineering principles and design concepts to medicine and biology. This field seeks to close the gap between engineering and medicine: It combines the design and problem solving skills of engineering with medical and biological sciences to improve...

  • Cochlear implant
    Cochlear implant
    A cochlear implant is a surgically implanted electronic device that provides a sense of sound to a person who is profoundly deaf or severely hard of hearing...

  • Ocular prosthetic
  • Organ (anatomy)
    Organ (anatomy)
    In biology, an organ is a collection of tissues joined in structural unit to serve a common function. Usually there is a main tissue and sporadic tissues . The main tissue is the one that is unique for the specific organ. For example, main tissue in the heart is the myocardium, while sporadic are...

  • Organ transplant
    Organ transplant
    Organ transplantation is the moving of an organ from one body to another or from a donor site on the patient's own body, for the purpose of replacing the recipient's damaged or absent organ. The emerging field of regenerative medicine is allowing scientists and engineers to create organs to be...

  • Plastic surgery
    Plastic surgery
    Plastic surgery is a medical specialty concerned with the correction or restoration of form and function. Though cosmetic or aesthetic surgery is the best-known kind of plastic surgery, most plastic surgery is not cosmetic: plastic surgery includes many types of reconstructive surgery, hand...

  • Prosthesis
    Prosthesis
    In medicine, a prosthesis, prosthetic, or prosthetic limb is an artificial device extension that replaces a missing body part. It is part of the field of biomechatronics, the science of using mechanical devices with human muscle, skeleton, and nervous systems to assist or enhance motor control...

  • Tissue scaffold

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK