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Autism Treatment : ABA, RDI, and Sensory Treatment

Saturday, 8 February 2014
Autism Treatment : ABA, RDI, and Sensory Treatment

Autism


Autism is a disorder of neural development characterized by impaired social interaction and verbal and non-verbal communication, and by restricted, repetitive or stereotyped behavior. The diagnostic criteria require that symptoms become apparent before a child is three years old. Autism affects information processing in the brain by altering how nerve cells and their synapses connect and organize; how this occurs is not well understood. It is one of three recognized disorders in the autism spectrum (ASDs), the other two being Asperger syndrome, which lacks delays in cognitive development and language, and pervasive developmental disorder, not otherwise specified (commonly abbreviated as PDD-NOS), which is diagnosed when the full set of criteria for autism or Asperger syndrome are not met.
Autism has a strong genetic basis, although the genetics of autism are complex and it is unclear whether ASD is explained more by rare mutations, or by rare combinations of common genetic variants. In rare cases, autism is strongly associated with agents that cause birth defects.Controversies surround other proposed environmental causes, such as heavy metals, pesticides or childhood vaccines; the vaccine hypotheses are biologically implausible and lack convincing scientific evidence. The prevalence of autism is about 1–2 per 1,000 people worldwide, and it occurs about four times more often in boys than girls.The Centers for Disease Control and Prevention (CDC) report 20 per 1,000 children in the United States are diagnosed with ASD as of 2012, up from 11 per 1,000 in 2008. The number of people diagnosed with autism has been increasing dramatically since the 1980s, partly due to changes in diagnostic practice and government-subsidized financial incentives for named diagnoses;the question of whether actual prevalence has increased is unresolved.

Causes


It has long been presumed that there is a common cause at the genetic, cognitive, and neural levels for autism's characteristic triad of symptoms. However, there is increasing suspicion that autism is instead a complex disorder whose core aspects have distinct causes that often co-occur.
Three diagrams of chromosome pairs A, B that are nearly identical. 1: B is missing a segment of A. 2: B has two adjacent copies of a segment of A. 3: B's copy of A's segment is in reverse order.
Deletion (1), duplication (2) and inversion (3) are all chromosome abnormalities that have been implicated in autism.[50]
Autism has a strong genetic basis, although the genetics of autism are complex and it is unclear whether ASD is explained more by rare mutationswith major effects, or by rare multigene interactions of common genetic variants. Complexity arises due to interactions among multiple genes, the environment, and epigenetic factors which do not change DNA but are heritable and influence gene expression.[20] Studies of twins suggest thatheritability is 0.7 for autism and as high as 0.9 for ASD, and siblings of those with autism are about 25 times more likely to be autistic than the general population.[40] However, most of the mutations that increase autism risk have not been identified. Typically, autism cannot be traced to a Mendelian(single-gene) mutation or to a single chromosome abnormality, and none of the genetic syndromes associated with ASDs have been shown to selectively cause ASD. Numerous candidate genes have been located, with only small effects attributable to any particular gene. The large number of autistic individuals with unaffected family members may result from copy number variations—spontaneous deletions or duplications in genetic material during meiosis.Hence, a substantial fraction of autism cases may be traceable to genetic causes that are highly heritable but not inherited: that is, the mutation that causes the autism is not present in the parental genome.
Several lines of evidence point to synaptic dysfunction as a cause of autism. Some rare mutations may lead to autism by disrupting some synaptic pathways, such as those involved with cell adhesion. Gene replacement studies in mice suggest that autistic symptoms are closely related to later developmental steps that depend on activity in synapses and on activity-dependent changes. All known teratogens (agents that cause birth defects) related to the risk of autism appear to act during the first eight weeks from conception, and though this does not exclude the possibility that autism can be initiated or affected later, it is strong evidence that autism arises very early in development.
Although evidence for other environmental causes is anecdotal and has not been confirmed by reliable studies, extensive searches are underway.Environmental factors that have been claimed to contribute to or exacerbate autism, or may be important in future research, include certain foods, infectious disease, heavy metals, solvents, diesel exhaust, PCBs, phthalates andphenols used in plastic products, pesticides, brominated flame retardants, alcohol, smoking, illicit drugs, vaccines, and prenatal stress, although no links have been found, and some have been completely disproven.
Parents may first become aware of autistic symptoms in their child around the time of a routine vaccination. This has led to unsupported theories blaming vaccine "overload", a vaccine preservative, or the MMR vaccine for causing autism.The latter theory was supported by a litigation-funded study that has since been shown to have been "an elaborate fraud". Although these theories lack convincing scientific evidence and are biologically implausible, parental concern about a potential vaccine link with autism has led to lower rates of childhood immunizations,outbreaks of previously controlled childhood diseases in some countries, and the preventable deaths of several children




Many children with autism and related disorders exhibit unwanted behaviors, such as head-banging or slapping others. For parents and other caregivers, trying to reduce these behaviors can be difficult and frustrating. In fact, efforts at discouragement often end up making the behaviors more frequent.
One approach for dealing with these issues is applied behavior analysis, or ABA, training. One of the most widely accepted autism therapies, 32 out of the 50 states in the U.S. have laws that require health insurers to cover it.

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Latest Treatment For Cancer

Thursday, 6 February 2014
Latest Treatment For Cancer




Cancer is a nearly invincible disease that has plagued humankind for centuries. Only in recent decades have doctors found effective ways to treat it. In that time we have also found better methods for early detection of this devastating disease. Despite great efforts to develop better treatments, more than 6 million people worldwide died from cancer in 1997. And we are still years away from any possible cure for cancer, something that many scientists think is impossible. While early detection is your best form of prevention, there are several techniques that are used to treat cancer. As you can read in our article on How Cancer Works, these techniques include:
  • Surgery
  • Radiation therapy
  • Chemotherapy
  • Hormone therapy
  • Immunotherapy






Surgery is the oldest and most widely used treatment available for cancer patients. About 60 percent of people diagnosed with cancer will undergo surgery, according to the American Cancer Society. If a growth is found early, doctors may opt to remove it before it has a chance to grow. Surgery is also used when there is a good chance to remove an entire tumor before it spreads. Surgery is rarely used as a stand-alone treatment. Usually, it is combined with radiation therapy and /or chemotherapy.
In radiation therapy, the specific part of the body containing a cancerous growth is exposed to radiation energy to attack reproducing cancer cells. However, the radiation cannot affect the cancer cells without affecting normal cells, which can lead to several unpleasant side effects, including fatigue, dryness and peeling of skin, nausea and vomiting. Radiation therapy is often used to shrink a tumor so that it can be removed through surgery, or to prevent tumor growth following surgery.
Chemotherapy, the treatment of cancer through drugs, is an effective treatment method for fighting cancerous cells that have spread to other parts of the body and that cannot be treated with any other method. There are dozens of cancer drugs that, in some cases, can cure the cancer, limit the spread of cancer and alleviate the symptoms of cancer. Similar to radiation therapy, chemotherapy also can affect normal cells, causing the same kinds of side effects.
Two more recent treatments for cancer are hormone therapy and immunotherapy. Hormone therapy involves anything that deals with manipulating the body's hormones to treat the cancer, including administering hormones and drugs. Doctors may also remove hormone glands to kill cancer cells or prevent further cancerous growth. Immunotherapy also manipulates the body's normal functions. During immunotherapy, patients are given medication to stimulate the body's immune system to fight cancerous cells.
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Top 5 Medical Technology Innovations

Sunday, 2 February 2014

Top 5 Medical  Technology Innovations



Against the backdrop of health care reform and a controversial medical device tax, medical technology companies are focusing more than ever on products that deliver cheaper, faster, more efficient patient care. They are also making inroads with U.S. Food & Drug Administration regulators to re-engineer the complex review and approval process for new medical devices.
Many in the industry have long felt overly burdened by what they consider to an unnecessarily complex approval process. Critics claim it impedes innovation and delays the availability of better health care. To change that perception, the FDA last year announced a new Medical Device Innovation Consortium (MDIC) charged with simplifying the process of designing and testing new technologies. With input from industry, government, and other nonprofit organizations, public-private MDIC will prioritize the regulatory science needs of the medical device community and fund projects to streamline the process.
"By sharing and leveraging resources, MDIC may help industry to be better equipped to bring safe and effective medical devices to market more quickly and at a lower cost," says Jeffrey Shuren, M.D., J.D., director of the FDA's Center for Devices and Radiological Health.
As the regulators, politicians, and corporate executives hash out these details, industry engineers and scientists continue to push through new ideas for improving and managing human health. Every year, industry observers like the Cleveland Clinic and the medical device trade press single out their favorite technology trends. These thought leaders agree that today's best technologies strike a balance between reducing the overall cost of medical care and increasing safety and survival rates—and isn't that what health care reform is all about?
Here are five emerging technologies to watch in the year ahead.


The MelaFind optica

1. Cutting Back on Melanoma Biopsies

With the most deadly form of skin cancer, melanoma, a huge number of dangerous-looking moles are actually harmless, but has always been impossible to know for sure without an invasive surgical biopsy. Today dermatologists have new help in making the right call — a handheld tool approved by the FDA for multispectral analysis of tissue morphology. The MelaFind optical scanner is not for definitive diagnosis but rather to provide additional information a doctor can use in determining whether or not to order a biopsy. The goal is to reduce the number of patients left with unnecessary biopsy scars, with the added benefit of eliminating the cost of unnecessary procedures. The MelaFind technology (MELA Sciences, Irvington, NY) uses missile navigation technologies originally paid for the Department of Defense to optically scan the surface of a suspicious lesion at 10 electromagnetic wavelengths. The collected signals are processed using heavy-duty algorithms and matched against a registry of 10,000 digital images of melanoma and skin disease.
The ATI Neurostimu

2. Electronic Aspirin

For people who suffer from migraines, cluster headaches, and other causes of chronic, excruciating head or facial pain, the "take two aspirins and call me in the morning" method is useless. Doctors have long associated the most severe, chronic forms of headache with the sphenopalatine ganglion (SPG), a facial nerve bundle, but haven't yet found a treatment that works on the SPG long-term. A technology under clinical investigation atAutonomic Technologies, Inc., (Redwood City, CA) is a patient-powered tool for blocking SPG signals at the first sign of a headache. The system involves the permanent implant of a small nerve stimulating device in the upper gum on the side of the head normally affected by headache. The lead tip of the implant connects with the SPG bundle, and when a patient senses the onset of a headache, he or she places a handheld remote controller on the cheek nearest the implant. The resulting signals stimulate the SPG nerves and block the pain-causing neurotransmitters.
The Symph

3. Needle-Free Diabetes Care

Diabetes self-care is a pain—literally. It brings the constant need to draw blood for glucose testing, the need for daily insulin shots and the heightened risk of infection from all that poking. Continuous glucose monitors and insulin pumps are today's best options for automating most of the complicated daily process of blood sugar management – but they don't completely remove the need for skin pricks and shots. But there's new skin in this game. Echo Therapeutics(Philadelphia, PA) is developing technologies that would replace the poke with a patch. The company is working on a transdermal biosensor that reads blood analytes through the skin without drawing blood. The technology involves a handheld electric-toothbrush-like device that removes just enough top-layer skin cells to put the patient's blood chemistry within signal range of a patch-borne biosensor. The sensor collects one reading per minute and sends the data wirelessly to a remote monitor, triggering audible alarms when levels go out of the patient's optimal range and tracking glucose levels over time.

The Telemedic

4. Robotic Check-Ups

A pillar of health reform is improving access to the best health care for more people. Technology is a cost-effective and increasingly potent means to connect clinics in the vast and medically underserved rural regions of the United States with big city medical centers and their specialists. Telemedicine is well established as a tool for triage and assessment in emergencies, but newmedical robots go one step further—they can now patrol hospital hallways on more routine rounds, checking on patients in different rooms and managing their individual charts and vital signs without direct human intervention. The RP-VITA Remote Presence Robot produced jointly by iRobot Corp. and InTouch Health is the first such autonomous navigation remote-presence robot to receive FDA clearance for hospital use. The device is a mobile cart with a two-way video screen and medical monitoring equipment, programmed to maneuver through the busy halls of a hospital.

The Sapien tra
5. A Valve Job with Heart

The Sapien transcatheter aortic valve is a life-saving alternative to open-heart surgery for patients who need new a new valve but can't endure the rigors of the operation. Manufactured by Edwards Life Sciences (Irvine, CA), the Sapienhas been available in Europe for some time but is only now finding its first use in U.S. heart centers—where it is limited only to the frailest patients thus far. The Sapien valve is guided through the femoral artery by catheter from a small incision near the grown or rib cage. The valve material is made of bovine tissue attached to a stainless-steel stent, which is expanded by inflating a small balloon when correctly placed in the valve space. A simpler procedure that promises dramatically shorter hospitalizations is bound to have a positive effect on the cost of care.


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Laser technology Allow Parkinsonism Patients To Wlk Again

Sunday, 2 February 2014

Laser technology Allow Parkinsonism Patients To Wlk Again




Researchers at the Mayo Clinic have developed a device that re-routes brain signals in Parkinsonism disorder patients, allowing them to regain mobility. For at least one patient in Florida, the device is having a life-changing impact.







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New Techonology That Will Change The future Of Medicines

Sunday, 2 February 2014
New Techonology That Will Change The future Of Medicines



From a spit test for cancer to a shot that helps your body re-grow nerves along your spinal cord, these new advances in the world of medicine blur the line between biology and technology—to help restore, improve and extend our lives







 1. Decay-Fighting Microbes

Bacteria living on teeth convert sugar into lactic acid, which erodes enamel and causes tooth decay. Florida-based company ONI BioPharma has engineered a new bacterial strain, called SMaRT, that cannot produce lactic acid—plus, it releases an antibiotic that kills the natural decay-causing strain. Dentists will only need to swab SMaRT, now in clinical trials, onto teeth once to keep them healthy for a lifetime. 

* 2. Artificial Lymph Nodes

Scientists from Japan's RIKEN Institute have developed artificial versions of lymph nodes, organs that produce immune cells for fighting infections. Though they could one day replace diseased nodes, the artificial ones may initially be used as customized immune boosters. Doctors could fill the nodes with cells specifically geared to treat certain conditions, such as cancer or HIV. 

* 3. Asthma Sensor

Asthma accounts for a quarter of all emergency room visits in the U.S., but a sensor developed at the University of Pittsburgh may finally cause that number to plummet. Inside the handheld device, a polymer-coated carbon nanotube—100,000 times thinner than a human hair—analyzes breath for minute amounts of nitric oxide, a gas that lungs produce prior to asthma attacks. 

* 4. Cancer Spit Test

Forget biopsies—a device designed by researchers at the University of California-Los Angeles detects oral cancer from a single drop of saliva. Proteins that are associated with cancer cells react with dyes on the sensor, emitting fluorescent light that can be detected with a microscope. Engineer Chih-Ming Ho notes that the same principle could be applied to make saliva-based diagnostic tests for many diseases. 

* 5. Biological Pacemaker

Electronic pacemakers save lives, but use hardware that eventually wears out. Now, researchers at several universities are developing a batteryless alternative: pacemaker genes expressed in stem cells that are injected into damaged regions of the heart. Better suited for physical exertion, biological pacemakers have been shown to bring slow canine hearts back up to speed without complications. 







6. Prosthetic Feedback

One challenge of prosthetic limbs is that they're difficult to monitor. "You and I sense where our limbs are spatially without having to look at them, whereas amputees don't," says Stanford University graduate student Karlin Bark. Skin is sensitive to being stretched—it can detect even small changes in direction and intensity—so Bark is developing a device that stretches an amputee's skin near the prosthesis in ways that provide feedback about the limb's position and movement. 

7. Smart Contact Lens

Glaucoma, the second-leading cause of blindness, develops when pressure builds inside the eye and damages retinal cells. Contact lenses developed at the University of California-Davis contain conductive wires that continuously monitor pressure and fluid flow within the eyes of at-risk people. The lenses then relay information to a small device worn by the patient; the device wirelessly transmits it to a computer. This constant data flow will help doctors better understand the causes of the disease. Future lenses may also automatically dispense drugs in response to pressure changes. 

8. Speech Restorer

For people who have lost the ability to talk, a new "phonetic speech engine" from Illinois-based Ambient Corporation provides an audible voice. Developed in conjunction with Texas Instruments, the Audeo uses electrodes to detect neuronal signals traveling from the brain to the vocal cords. Patients imagine slowly sounding out words; then the quarter-size device (located in a neck brace) wirelessly transmits those impulses to a computer or cellphone, which produces speech. 

9. Absorbable Heart Stent

Stents open arteries that have become narrowed or blocked because of coronary artery disease. Drug-eluting stents release medication that keeps the artery from narrowing again. The bio-absorbable version made by Abbott Laboratories in Illinois goes one step further: Unlike metal stents, it does its job and disappears. After six months the stent begins to dissolve, and after two years it's completely gone, leaving behind a healthy artery. 


10. Muscle Stimulator

In the time it takes for broken bones to heal, nearby muscles often atrophy from lack of use. Israeli company StimuHeal solves that problem with the MyoSpare, a battery-operated device that uses electrical stimulators—small enough to be worn underneath casts—to exercise muscles and keep them strong during recovery. 

11. Nerve Regenerator

Nerve fibers can't grow along injured spinal cords because scar tissue gets in the way. A nanogel developed at Northwestern University eliminates that impediment. Injected as a liquid, the nanogel self-assembles into a scaffold of nanofibers. Peptides expressed in the fibers instruct stem cells that would normally form scar tissue to produce cells that encourage nerve development. The scaffold, meanwhile, supports the growth of new axons up and down the spinal cord. 

12. Stabilizing Insoles

When Erez Lieberman's grandmother suffered a dangerous fall, he wanted to ensure it never happened again. "But it wasn't till a few years later at NASA that I found a way to channel that into something tangible," says the MIT graduate student. Using technology developed to monitor the balance of astronauts who have just returned from space, Lieberman's iShoe analyzes the pressure distribution of the feet. Doctors can use the insole to diagnose balance problems in elderly patients before falls occur. 

13. Smart Pill

California-based Proteus Biomedical has engineered sensors that track medication use by recording the exact time drugs are ingested. Sand-grain-size microchips emit high-frequency electrical currents that are logged by Band-Aid-like receivers on the skin. The receivers also monitor heart rate and respiration and wirelessly transmit the data to a computer. "To really improve pharmaceuticals, we need to do what is now common in every other industry—embed digital technology into existing products and network them," says David O'Reilly, senior vice president of corporate development. 

14. Autonomous Wheelchair

MIT researchers have developed an autonomous wheelchair that can take people where they ask to go. The chair learns about its environment by listening as a patient identifies locations—such as "this is my room" or "we're in the kitchen"—and builds maps using Wi-Fi, which works well indoors (unlike GPS). The current model, which is now being tested, may one day be equipped with cameras, laser rangefinders and a collision- avoidance system. 








15. Gastrointestinal Liner

Obesity is associated with type II diabetes, which over time wears out the pancreas. A gastrointestinal liner developed by Massachusetts-based GI Dynamics may restore the obese to a healthy weight by preventing food from contacting the intestinal wall. The Endobarrier is routed endoscopically through the mouth—unlike a gastric bypass, no surgery is necessary—and lines the first 2 ft of the small intestine, where the most calories are absorbed (nutrients are still absorbed farther down the intestine). 

16. Liver Scanner

How healthy is your liver? Until recently, answering that question often required a painful biopsy. French company EchoSens has developed a machine that scans the organ for damage in just 5 minutes. Studies have shown that damaged livers become stiffer and less elastic, so the scanner, called the Fibroscan, measures the organ's elasticity using ultrasound. 

 17. Nanoscale Adhesive

Gecko feet are covered with nano-size hairs that exploit intermolecular forces, allowing the lizards to stick firmly to surfaces. By replicating this nanoscale topography, MIT scientists have developed an adhesive that can seal wounds or patch a hole caused by a stomach ulcer. The adhesive is elastic, waterproof and made of material that breaks down as the injury heals. 

18. Portable Dialysis

More than 15 million adult Americans suffer from diseases of the kidneys, which often impair the ability of the organs to remove toxins from the blood. Standard dialysis involves three long sessions at a hospital per week. But an artificial kidney developed by Los Angeles-based Xcorporeal can clean blood around the clock. The machine is fully automated, battery-operated, waterproof and, at less than 5 pounds, portable. 

19. Walking Simulator

Stroke victims are being tricked into recovering more quickly with a virtual-reality rehabilitation program developed at the University of Portsmouth in Britain. As patients walk on a treadmill, they see moving images that fool their brains into thinking they are walking slower than they are. As a result, patients not only walk faster and farther, but experience less pain while doing so. 

20. Rocket-Powered Arm

Adding strength to prosthetic limbs has typically required bulky battery packs. Vanderbilt University scientist Michael Goldfarb came up with an alternative power source: rocket propellant. Goldfarb's prosthetic arm can lift 20 pounds—three to four times more than current prosthetics—thanks to a pencil-size version of the mono-propellant rocket-motor system used to maneuver the space shuttle in orbit. Hydrogen peroxide powers the arm for 18 hours of normal activity. 

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3D printing ( FUTURE OF PRODUCTION ) or ( DISASTER )

Saturday, 1 February 2014
3D printing or Additive manufacturing is a process of making a three-dimensional solid object of virtually any shape from a digital model. 3D printing is achieved using an additive process, where successive layers of material are laid down in different shapes. 3D printing is also considered distinct from traditional machining techniques, which mostly rely on the removal of material by methods such as cutting or drilling (subtractiveprocesses).
A 3D printer is a limited type of industrial robot that is capable of carrying out an additive process under computer control.
While 3D printing technology has been around since the 1980s, it was not until the early 2010s that the printers became widely available commercially.The first working 3D printer was created in 1984 by Chuck Hull of 3D Systems Corp. Since the start of the 21st century there has been a large growth in the sales of these machines, and their price has dropped substantially. According to Wohlers Associates, a consultancy, the market for 3D printers and services was worth $2.2 billion worldwide in 2012, up 29% from 2011.
The 3D printing technology is used for both prototyping and distributed manufacturing with applications in architecture, construction (AEC), industrial design, automotive, aerospace, military, engineering, civil engineering, dental and medical industries, biotech (human tissue replacement), fashion, footwear, jewelry, eyewear, education, geographic information systems, food, and many other fields. One study has found that open source 3D printing could become a mass market item because domestic 3D printers can offset their capital costs by enabling consumers to avoid costs associated with purchasing common household objects.

General principles

3D Printable Models

3D printable models may be created with a computer aided design package or via 3D scanner. The manual modeling process of preparing geometric data for 3D computer graphics is similar to plastic arts such as sculpting. 3D scanning is a process of analyzing and collecting data of real object; its shape and appearance and builds digital, three dimensional models.
Both manual and automatic creation of 3D printable models is difficult for average consumers. This is why several 3D printing marketplaces have emerged over the last years. Among the most popular are Shapeways, Thingiverse and Threeding 

Printing

To perform a print, the machine reads the design from an STL file and lays down successive layers of liquid, powder, paper or sheet material to build the model from a series of cross sections. These layers, which correspond to the virtual cross sections from the CAD model, are joined or automatically fused to create the final shape. The primary advantage of this technique is its ability to create almost any shape or geometric feature.
Printer resolution describes layer thickness and X-Y resolution in dpi (dots per inch), or micrometers. Typical layer thickness is around 100 Âµm (250 DPI), although some machines such as the Objet Connex series and 3D Systems' ProJet series can print layers as thin as 16 µm (1,600 DPI).[19] X-Y resolution is comparable to that of laser printers. The particles (3D dots) are around 50 to 100 µm (510 to 250 DPI) in diameter.
Construction of a model with contemporary methods can take anywhere from several hours to several days, depending on the method used and the size and complexity of the model. Additive systems can typically reduce this time to a few hours, although it varies widely depending on the type of machine used and the size and number of models being produced simultaneously.
Traditional techniques like injection molding can be less expensive for manufacturing polymer products in high quantities, but additive manufacturing can be faster, more flexible and less expensive when producing relatively small quantities of parts. 3D printers give designers and concept development teams the ability to produce parts and concept models using a desktop size printer.

Finishing

Though the printer-produced resolution is sufficient for many applications, printing a slightly oversized version of the desired object in standard resolution and then removing material with a higher-resolution subtractive process can achieve greater precision.
Some additive manufacturing techniques are capable of using multiple materials in the course of constructing parts. Some are able to print in multiple colors and color combinations simultaneously. Some also utilize supports when building. Supports are removable or dissolvable upon completion of the print, and are used to support overhanging features during construction.

TypeTechnologiesMaterials
ExtrusionFused deposition modeling (FDM)Thermoplastics (e.g. PLA, ABS), HDPE, eutectic metals, edible materials, Rubber (Sugru), Modelling clay, Plasticine, RTV silicone, Porcelain, Metal clay (including Precious Metal Clay)
WireElectron Beam Freeform Fabrication(EBF3)Almost any metal alloy
GranularDirect metal laser sintering (DMLS)Almost any metal alloy
Electron-beam melting(EBM)Titanium alloys
Selective laser melting(SLM)Titanium alloys, Cobalt Chrome alloys, Stainless Steel, Aluminium
Selective heat sintering(SHS) [25]Thermoplastic powder
Selective laser sintering(SLS)Thermoplastics, metal powders, ceramic powders
Powder bed and inkjet head 3D printingPlaster-based 3D printing (PP)Plaster
LaminatedLaminated object manufacturing (LOM)Paper, metal foil, plastic film
Light polymerisedStereolithography (SLA)photopolymer
Digital Light Processing(DLP)photopolymer

Mask-image-projection-based stereolithography


In this technique a 3D digital model is sliced by a set of horizontal planes. Each slice is converted into a two-dimensional mask image. The mask image is then projected onto a photocurable liquid resin surface and light is projected onto the resin to cure it in the shape of the layer.
In research systems, the light is projected from below, allowing the resin to be quickly spread into uniform thin layers, reducing production time from hours to minutes.
The technique has been used to create objects composed of multiple materials that cure at different rates.
Commercially available devices such as Objet Connex apply the resin via small nozzles

Consumer use

RepRap version 2.0 (Mendel).
MakerBot Cupcake CNC.
Printing in progress in a MakerBot 3D printer during Mozilla Maker party, Bangalore
Airwolf 3D AW3D v.4 (Prusa).
Several projects and companies are making efforts to develop affordable 3D printers for home desktop use. Much of this work has been driven by and targeted at DIY/enthusiast/early adopter communities, with additional ties to the academic and hacker communities.
RepRap is one of the longest running projects in the desktop category. The RepRap project aims to produce a free and open source software (FOSS) 3D printer, whose full specifications are released under the GNU General Public License, and which is capable of replicating itself by printing many of its own (plastic) parts to create more machines. Research is under way to enable the device to print circuit boards and metal parts.
Because of the FOSS aims of RepRap, many related projects have used their design for inspiration, creating an ecosystem of related or derivative 3D printers, most of which are also open source designs. The availability of these open source designs means that variants of 3D printers are easy to invent. The quality and complexity of printer designs, however, as well as the quality of kit or finished products, varies greatly from project to project. This rapid development of open source 3D printers is gaining interest in many spheres as it enables hyper-customization and the use of public domaindesigns to fabricate open source appropriate technology through conduits such as Thingiverse and Cubify. This technology can also assist initiatives insustainable development since technologies are easily and economically made from resources available to local communities.
The cost of 3D printers has decreased dramatically since about 2010, with machines that used to cost $20,000 costing less than $1,000. For instance, as of 2013, several companies and individuals are selling parts to build various RepRap designs, with prices starting at about €400 /US$500.The open source Fab@Home project has developed printers for general use with anything that can be squirted through a nozzle, from chocolate to silicone sealant and chemical reactants. Printers following the project's designs have been available from suppliers in kits or in pre-assembled form since 2012 at prices in the US$2000 range. The Kickstarter funded Peachy Printer is designed to cost $100and several other new 3D printers are aimed at the small, inexpensive market including the mUVe3D and Lumifold. Professional grade 3D-printer crowdsourced costing $1499 is designed by Rapide 3D and has no fumes nor constant rattle during use.
As the costs of 3D printers have come down they are becoming more appealing financially to use for self-manufacturing of personal products.[8] In addition, 3D printing products at home may reduce the environmental impacts of manufacturing by reducing material use and distribution impacts.
The development and hyper-customization of the RepRap-based 3D printers has produced a new category of printers suitable for small business and consumer use. Manufacturers such as Solidoodle, RoBo, and RepRapPro have introduced models and kits priced at less than $1,000, thousands less than they were in September 2012. Depending on the application, the print resolution and speed of manufacturing lies somewhere between a personal printer and an industrial printer. A list of printers with pricing and other information is maintained. Most recently delta robots, like theTripodMaker, have been utilized for 3D printing to increase fabrication speed further.For delta 3D printers, due to its geometry and differentiation movements, the accuracy of the print depends on the position of the printer head.
Some companies are also offering software for 3D printing, as a support for hardware manufactured by other companies


Great Contribution In The Field Of Meical 

Tissue engineering is the use of a combination of cells, engineering and materials methods, and suitable biochemical and physio-chemical factors to improve or replace biological functions. While it was once categorized as a sub-field of bio materials, having grown in scope and importance it can be considered as a field in its own right.
While most definitions of tissue engineering cover a broad range of applications, in practice the term is closely associated with applications that repair or replace portions of or whole tissues (i.e., bone, cartilage, blood vessels, bladder, skin, muscle etc.). Often, the tissues involved require certain mechanical and structural properties for proper functioning. The term has also been applied to efforts to perform specific biochemical functions usingcells within an artificially-created support system (e.g. an artificial pancreas, or a bio artificial liver). The term regenerative medicine is often used synonymously with tissue engineering, although those involved in regenerative medicine place more emphasis on the use of stem cells to produce tissues.




Organ-on-a-chip


An Organ-on-a-Chip (OC) is a multi-channel 3-D microfluidic cell culture chip that simulates the activities, mechanics and physiological response of entire organs and organ systems.[1] It constitutes the subject matter of significant biomedical engineering research, more precisely in bio-MEMS. The convergence of Lab-on-Chips (LOCs) and cell biology has permitted the study ofhuman physiology in an organ-specific context, introducing a novel model of in vitro multicellular human organisms. One day, they will perhaps abolish the need for animals in drug development and toxin testing.
Although multiple publications claim to have translated organ functions onto this interface, the movement towards this microfluidic application is still in its infancy. Organs-on-chips will vary in design and approach between different researchers. As such, validation and optimization of these systems will likely be a long process. Organs that have been simulated by microfluidic devices include the heart, the lung, kidney, artery, bone, cartilage, skin and more.
Nevertheless, building valid artificial organs requires not only a precise cellular manipulation, but a detailed understanding of the human body’s fundamental intricate response to any event. A common concern with Organs-on-Chips lies in the isolation of organs during testing. “If you don’t use as close to the total physiological system that you can, you’re likely to run into troubles”says William Haseltine, founder of Rockville, MD. Microfabrication, microelectronics and microfluidics offer the prospect of modeling sophisticated in vitro physiological responses under accurately simulated conditions.





Disadvantages of 3D Printers



In the prototyping sector of product development, 3D printing is lauded as being a fast, efficient means of creating parts to test for form, fit and function before said parts go into the manufacturing stage of development. While 3D printing is a viable technology in terms of validating parts and making sure that no design and engineering tweaks are necessary before any product is green-lighted for production, there are disadvantages in using the technology as well. These range from a limited use of materials to questions over whether the technology is feasible for short-run and long-run manufacturing.

Limited Materials

3D printed parts are built in additive fashion -- that is, layer-by-layer from the ground up. While the technology is a major process breakthrough, the materials that can be used are still limited. For instance, the 3D printing material of choice is plastic, as it can be deposited down in melted layers to form the final part. The kinds of plastic vary among the likes of high-strength and high temperature materials, so part strength can't accurately be tested in many cases. Some developers are offering metal as a material, but final parts often are not fully dense. There are several more specialized materials that companies are printing in, such as glass and gold, but such technologies have yet to be commercialized.


Manufacturing Limitations

3D printing is perfect for creating prototype parts because it's an economical, inexpensive way of creating one-run parts for which you don't have to create tooling. Parts typically are created in hours and changes to the design and engineering of the part can be made in a CAD (computer-aided design) file after the part is analyzed. But in terms of a manufacturing process, 3D printing is not a realistic option as of the date of publication. In manufacturing processes such as thermoforming and stamping, several parts are typically made in one minute, not hours.

Size

Parts created additively through 3D printing are also limited in size. For instance, the most affordable, common 3D printing machines typically are small enough to fit on your desktop, meaning they have build chamber sizes of similar proportions. There are 3D printers that are able to create larger parts, but they're much more expensive and thereby an unrealistic option for many companies. As a general rule of thumb, the larger the part that needs to be fabricated, the longer it takes to create.




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