139 megapixel chip needed for retinal substitute

139 megapixel chip needed for retinal substitute


this article is from 2007 when  cell phone cameras were not ubiquitous.

so what is the progress in the last 12 year ?

Published online 21 March 2007 | Nature | doi:10.1038/news070319-7

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A chip in the eye boosts sight

Amplification of light restores limited vision in some damaged retinas.

Ned Stafford

Retina Implant

The first test of an electrically boosted light-sensitive electronic chip implanted into the eye shows that it can restore sight to some blind patients.

This is another step in what is now a highly competitive — and commercial — global race to help the blind see again.

Eberhart Zrenner, executive director of the Eye Hospital at the University of Tübingen in Germany, announced at a recent press conference that his team had surgically implanted a 3-millimetre-square chip behind the retina of one eye in seven legally blind patients between the ages of 26 and 58. The chips restored limited vision to three of the patients, Zrenner said. The group will present its results at the Association for Research in Vision and Ophthalmology annual meeting in Fort Lauderdale, Florida, in May.

The chips were developed and made by Retina Implant of Reutlingen, Germany, a start-up company co-founded by Zrenner. Walter Wrobel, chief executive officer of the company, says they will now "fine tune" the chips and have them ready to market in 2009 at a price of €25,000 each. "We now know what improvements need to be made and we need more tests."

Broken retina

Research groups around the world are working on various type of implant designed to restore sight to people who have lost retinal function. Implants can work for conditions such as age-related macular degeneration or retinitis pigmentosa, but not for blindness caused by glaucoma or diabetes, among other conditions.

What distinguishes the Retina Implant from other sub-retinal devices is that it is powered by electricity to amplify the images, says Wrobel. The chip contains 1,500 light-sensitive microelectrodes, each generating a picture element (pixel), and each with an amplifier that boosts the signal delivered to stimulate the retina. The device is implanted in a five-hour operation, with a wire running out of the eye socket, under the skin, to behind the patient's ear. This is then connected to a power source.

For two of the patients who showed no improvement in the trial there were technical problems with the chips; two others had been blind for more than 10 years, and so seemed to have lost the ability to interpret the light signals.

The three patients in whom the chip worked reported seeing "sort of an illuminated window frame", in which they had limited vision. One was able to locate white dinner plates on a dark tablecloth, for example, but could not locate white plastic packages of coffee creamer.

"The patients were absolutely enthusiastic about it, to see light or find a plate on the table in front of them," says Wrobel. "For them, it was tremendous progress." A key to future success will be teaching patients to interpret the images better, he says.

Long-term effects of the implants are not yet known: six of the seven patients carried the implant for 30 days, after which it was surgically removed. The seventh patient carried the chip for 18 months with no complaints.

Tough competition

The German project is just one among many aiming to fix faulty retinas. Alan Chow at Rush University Medical Center in Chicago is a co-founder of Optobionics of Naperville, Illinois. His team has a sub-retinal implant that works without amplification, and is powered only by the incoming light. "We have demonstrated that a passive device works," Chow says, adding: "With ours there is no need for an exit wire."

An artificial silicon retina developed by Optobionics, with 5,000 microscopic solar cells, each with its own stimulating electrode, has been tested in ten people in a trial that began in 2000. The company says that sight improved for all of them. Chow says some have seen colours and others have been able to see their own face in a mirror. But Wrobel still argues that amplification is necessary to truly restore sight.

Yet another group, led by the Doheny Eye Institute at the University of Southern California in Los Angeles, is working on an implant that requires the patient to wear a tiny camera and microprocessor mounted in eyeglasses, along with an implant, a receiver and a battery pack.

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A device developed by Second Sight, a company involved with the Doheny project, has been in human trials since 2002. The first generation of these implants enabled a formerly blind patient to distinguish between objects on a table and make out large letters (see 'Artificial retina gets diamond coating'). A new device with more pixels is set to be tested soon, the team reported at the recent meeting of the American Association for the Advancement of Science in San Francisco.

But some say the small camera is clunky and intrusive. "I do not see this as practical," Wrobel says.

Brian Mech, senior director of business development at Second Sight, says Retina Implant has not presented much data publicly, making it difficult to comment on any advantages this system may offer.

Visit our chipintheeyeboostssight.html">newsblog to read and post comments about this story.  

Artificial retina gets diamond coating

Nanofilm will protect electronic implant.

Mark Peplow

The eyes have it: retinal implants could give sight back to people blinded by disease.© Punchstock

A bionic eye that allows blind people to see has now got a protective coat of diamond that should significantly improve its performance.

The silicon chip retinal implant is being developed by Second Sight, a company based in Sylmar, California, along with a consortium of university researchers. The device needs a hermetic case to prevent it from reacting with fluids in the eye.

"It's as if you're throwing a television into the ocean and expecting it to work," says the company's president, Robert Greenberg. "The approach until now has been to lock it in a big waterproof can, but it's very big and bulky," he explains.

So researchers have developed an ultrananocrystalline diamond (UNCD) film that is guaranteed to be safe, long-lasting, electrically insulating and extremely tough. The coating can also be applied at low temperatures that do not melt the chip's microscopic circuits.

“It's as if you're throwing a television into the ocean and expecting it to work.”

The UNCD film is the first coating to meet all the necessary criteria for the implant, says Xingcheng Xiao, a materials scientist at Argonne National Laboratory, Illinois, who developed the film.

The tiny diamond grains that make up the film are about 5 millionths of a millimetre across. They grow from a mixture of methane, argon and hydrogen passing over the surface of the five-millimetre-square chip at about 400 °C. Xiao and his colleagues have already tested the implants in rabbits' eyes, and saw no adverse reaction after six months. He will present the results on 1 April at the Materials Research Society meeting in San Francisco, California.

Lighter load

A healthy retina contains rod and cone cells that convert light into electrical impulses, which fly to the brain through the optic nerve. But for millions of people with diseases such as retinitis pigmentosa or macular degeneration, these cells do not work properly.

The retinal implant bypasses these diseased cells by electrically stimulating healthy cells that sit beneath them at the back of the eyeball. The patient 'sees' using a pair of glasses carrying a tiny video camera that sends digitized images to the implant using radio waves.

The first human trial of Second Sight's artificial retina has been running since 2002, and it has enabled a formerly blind patient to distinguish between objects such as cups and plates, and even to make out large letters. But with only 16 electrodes, the device does not allow the patient to see a clear picture. For that, thousands of electrodes are needed on the same size of chip, making it even more delicate.

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In the first trial, the electronics package was separated from the electrodes and implanted behind the patient's ear because its casing was so bulky, explains Greenberg. The team's goal is to integrate everything into a single unit that fits neatly into the eye. Xiao adds that a UNCD coating could be equally useful for other implantable devices, such as biosensors to monitor a patient's health.

"They've managed to create a diamond film that is of considerably higher quality than other methods have managed," says Doug Shire, a materials engineer at Cornell University in Ithaca, New York, who is part of the Boston Retinal Implant Project. "But the ultimate potential of these devices will only be told in long-term trials," he adds.

Second Sight is planning clinical trials of a 60-electrode device this year, but it may be several more years before the diamond-coated chip is used in humans, says Greenberg. 

President of Second Sigh

The Evidence: The Gap Between Guidelines and Clinical Reality

The Evidence: The Gap Between Guidelines and Clinical Reality

 Increasing the effectiveness of adherence interventions may have a far greater impact on the health of the population than any improvement in specific medical treatments
 – since a medication that is prescribed but not taken, is ineffective.

formal definition of true clinical inertia: physician behavior falls under Clinical Inertia if and only if 1. a Guideline (G) exists, explicit or implicit 2. the doctor (D) knows the Guideline (G) 3. the doctor (D) thinks that this Guideline (G) applies to the patient (P) 4. the doctor (D) has the resources to apply the Guideline (G) 5. conditions 1–4 have been met, yet the doctor (D) does not follow the Guideline (G) in the case of the patient (P). 

Retinal Detachment growth factors

(I-SMA a-smooth muscle actin
ACAID Antefior chamber-associated immune deviation
APCs Antigen-presenting cells
b-FGF Basic fibroblast growth factor
CTGF Connective tissue growth factor
 ECM Extracellular matrix
ERM Epiretinal (actually premacular) membrane
CJFPGlial fibrillary acidic protein
HCJF Green fluorescent protein
HGF Hepatocyte growth factor
Hypoxia-inducible factor-I
IGF-I Insulin-like growth factor-I
ILM Inner limiting membrane
¯MCP- I AMonocyte chemoattractant protein-
MLC Myosin light chain
HIF-I IGF-I ILM MCP-I MLC PDGF PDR PMM PVR ROCK RPE TGF-ß TNF-(I uPA VCAID VEG Hypoxia-inducible factor-I Insulin-like growth fact01%l Inner limiting membrane Monocyte chemoattractant protein-I Myosin light chain Platelet-derived growth factor Proliferative diabetic retinopathy Premacular membrane Posterior vitreous detachment Proliferative vitreoretinopathy Rho kinase Retinal pigment epithelium Transforming growth factor-I) Tumor necrosis factor-u Urokinase-type plasminogen activator Vitreous cavity-associated immune deviation

Nawab's laddu

Long time ago there was a small Kingdom in India which was ruled by a nawab. he  employed a physician who in Urdu is called a Hakeem.

Nawab was diagnosed with diabetes.

Hakeem was giving him dietary instructions to control his blood sugar.

One of the instructions was not to eat anything sweet.

Nawab was used to eating lot's of sweets specially laddus.

he begged the Hakeem to make an exception for this particular sweet.

Hakeem relented and told him” Jahapana  you are allowed to eat one half of a laddu every week.

After a few weeks Hakeem noticed  That the blood sugar of the nawab was sky-high.

He inquired with the chief cook, he was informed that the nawab was only eating One half laddu every week.

The Hakeem was intrigued and asked the chief cook to show him what kind of laddu the Nawab was eating.

A large plate Carried by four servants was brought in and once the cover was removed.

The Hakeem could not stop laughing because the plate contained just  half a laddu .

The only interesting thing was the laddu was 2 feet tall and was weighing about 25 kilograms.  

The moral of the story is every doctor has to be very specific in his instructions to his patients.
Otherwise they will always find some way or the other to defeat the purpose of the physician's instructions.

a distrust of the “rule of the hour”

 The discord between theoretically possible and desirable results and those obtained in current xvi practice implies numerous responsibilities. They fall roughly into three areas.
 (1) The health care system in general, its imperfect organization, its limited accessibility.
(2) The people with a disease and their lack of adherence .
 (3) The health care providers and their inertia.

 Those who worked on chronic inflammatory rheumatism and hypertension had chosen the word of observance to express the concordance between patient behavior and doctor prescriptions, with a touch of religious rule which translated the physician-patient relationship such as it was conceived and wished at the beginning of the 1970s.

 In a first analysis, the lack of adherence can be felt as disobedience by patients, and the inertia of doctors as lack of conscientiousness and a superficiality of their practices. I’m doing what you prescribed, says the patient, without following the entire diet and without always taking all medications. I’m doing enough for you, says the doctor to her patient, without modifying a treatment which is working poorly, or even not at all. According to this mode of reasoning, it is necessary to obtain a “confession” of her nonadherence from the patient, to make her correct it (no, doctor, I did not take your …, it gives me a stomach ache. Impossible, take it or I cannot make you better…) In the same way, one must just as rationally denounce inertia (it’s not perfect, but it’s better than nothing, says the doctor, and the common sense of both partners makes them prefer the probability of not having the disease which one wants to prevent over the complexity of the prescription and the risk of the treatment …)

 Likewise, can medical inertia translate a distrust of the “rule of the hour”, and the norm? In a medicine defined by norms, is the justification of these norms sufficient to transform them into a quality requirement? In reality, the norm arises from clinical trials performed on volunteer people by volunteer health care providers , and their external validity is unreliable because 90 % of the people on whom the treatments are applied are not included in the scientific studies, generally due to a social, psychological or medical complexity.

The lower the better, it is said, for blood Foreword to the French Edition xvii pressure, glycated hemoglobin, or cholesterol levels, generally based on observational studies associated with randomized clinical trials . But in daily life, age is associated with multiple pathologies, prescriptions become longer, psychology includes distrust and doubt.

Clinical Inertia and Nonadherence by Patients

First law of motion , or principle of inertia :
Every body persists in its state of being at rest or of moving uniformly straight forward ,
except insofar as it is compelled to change its state by force impressed.

 Sir Isaac Newton, Mathematical Principles
 of Natural Philosophy (1687)

Insanity : doing the same thing over and over again and expecting different results .

 Einstein \
 Nonadherence by Patients It might seem that nonadherenc e by patients to a medical or behavioral regime prescribed to them by their doctors can only be characterized as irrational. They want to get better; they know what to do to get better; and yet they don ’ t do it . In some cases, this characterization seems correct. Patients may fail to take their medication because it reminds them of their mortality, just as people sometimes put off writing a will until it’s too late because they don’t want to entertain the thought of their death. Anyone can forget to take their medication, but sometimes the forgetfulness is motivated . They may fail to do their midday injection because they would feel ashamed to do so in front of their peers .
 People who are told by their doctor to cut down their wine consumption to two glasses a day, may start using larger glasses;
Like the Nawab's laddu story

the initial enthusiasm to fight an illness typically wanes with time. As these energetic but short-lived emotions wane, so does treatment adherence . In this case, the irrationality consists in the failure to understand that the emotion is unlikely to last – the “hot-to-cold empathy gap”

but are there any more realistic technologies of self-control available? One possibility would be an automated phone-call, “It is time to take your daily medication”. If the doctor has ordained regular physical exercise, the patient can motivate himself by going to a fitness center where he pays a large down payment that is reimbursed in part after each visit.

 patients sometimes do not want to exercise their autonomy, preferring to leave the decisions in the hand of the doctor. In a variation on a phrase by T. S. Eliot, one might say that humankind cannot bear very much freedom. Some people, though, are obsessed with their freedom and Foreword xi autonomy of choice, and hate doing what they are told to do.

Let me mention some sources of rational non- compliance . First, there may be rational distrust of the doctor – either of the doctor’s competence or of his honesty . In the case of psychiatric treatment, for instance, the low degree of intersubjective agreement among doctors that belong to different schools of thought would seem to justify skepticism and sometimes nonadherence. Prescription of medication for attention deficit disorder may be an example. In the case of surgeons, their notorious eagerness to operate, sometimes motivated by a financial interest, can justify resistance to their advice. Four years ago, a doctor told me that I needed to have knee surgery immediately, since there was no cartilage left, only “bone on bone”. I discarded the advice, and instead lost weight, resumed biking, and am doing just fine. In such cases, one might want to seek a second opinion – but not tell the second doctor what the first doctor concluded!
 The mirror image of rational distrust is that of irrational trust . When deciding whether to follow the doctor’s advice, patients may attach unwarranted importance to his or her bedside manners. Psychologists have labeled this phenomenon the halo effect , and found it in a number of situations. “If we think a baseball pitcher is handsome and athletic, for example, we are likely to rate him better at throwing the ball, too” ( Kahneman 2011, p. 199). Patients, in other words, should learn to distrust their trust , just as doctors should learn to distrust their beliefs in their own competence and be willing to admit ignorance (see below). Second, there may be excusable ignorance on the patient’s part. As Dr. Reach mentions, if the doctor fails to educate the patient, he or she may pay excessive attention to the list of scary secondary effects – most of them very rare – that are usually listed on the instruction sheet that comes with the medication. In a very different set of cases, the patient may be exposed to a biased sample. People on dialysis sometimes refuse an offer to get a transplantation because the only transplantees they meet at the dialysis center are those whose grafts failed to take.


Among the sources of irrational or unjustified nonadherence, Dr. Reach singles out, once again, myopia as a main culprit. In a phrase, myopia causes inertia , that is, under-treatment or non-treatment. Before I proceed, I want to mention the possibility of overtreatment , not, as in the case of my knee-surgery, because of the pecuniary interest of the doctor, but because of an engrained medical “tendency toward action rather than inaction ”. Such an error is more likely to happen with a doctor who is overconfident, whose ego is inflated, but it can also occur when a physician is desperate and gives in to the urge to ‘ do something ’. The error, not infrequently, is sparked by pressure from a patient, and it takes considerable effort for a doctor to resist. ‘Don’t just do something, stand there’, Dr. Linda Lewis, one of my mentors once said when I was unsure of a diagnosis”. (Groopman 2007, p. 169; emphasis added). Even when the recommended procedure is to “wait and see”, the doctor’s inaction - aversion might get the better of him.
 rationality and morality do not coincide, any more than do rationality and wisdom.

 Almost without exception, a simple mechanical formula based on a few variables will outperform the diagnoses and prognoses of experts, including doctors

Groping after straws, terminal cancer patients often ignore the evidence-based advice of the oncologist and turn instead to a quack. By contrast, we would expect doctors to be calm, detached, and rational in their role as mediators between the medical authorities and the patients, disregarding recommendations when and only when they have adequate reasons for doing so. Unlike the patient, they have nothing at stake. As Dr. Reach shows, however, this idyllicizing picture is inaccurate. The amour-propre of doctors is at stake, and so is their professional reputation. Also, like the rest of us, doctors are subject to the horror vacui : “Many of this world’s abuses are engendered – or to put it more rashly, all of this world’s abuses are engendered – by our being schooled to be afraid to admit our ignorance and because we are required to accept anything which we cannot refute”

from  Gérard Reach Clinical Inertia