Light-powered bionic eye invented to help restore sight

A retinal implant - or bionic eye - which is powered by light has been invented by scientists at Stanford University in California.

Implants currently used in patients need to be powered by a battery.

The new device, described in the journal Photonics, uses a special pair of glasses to beam near infrared light into the eye.

This powers the implant and sends the information which could help a patient see.

Diseases such as age-related macular degeneration and retinal pigmentosa result in the death of cells which can detect light in the eye.

Eventually this leads to blindness.

Wiring eliminated

Retinal implants stimulate the nerves in the back of the eye, which has helped some patients to see.

Early results of a trial in the UK mean two men have gone from being totally blind to being able to perceive light and even some shapes.

However, as well as a fitting a chip behind the retina, a battery needs to be fitted behind the ear and a cable needs to join the two together.

Prof Robert MacLaren from Oxford Eye Hospital explains how a bionic eye implant works

The Stanford researchers say their method could be a step forward by "eliminating the need for complex electronics and wiring".

A retinal implant, which works in a similar way to a solar panel, is fitted in the back of the eye.

A pair of glasses fitted with a video camera records what is happening before a patient's eyes and fires beams of near infrared light on to the retinal chip.

The creates an electrical signal which is passed on to nerves.

Natural light is 1,000 times too weak to power the implant.

The researchers said: "Because the photovoltaic implant is thin and wireless, the surgical procedure is much simpler than in other retinal prosthetic approaches.

"Such a fully integrated wireless implant promises the restoration of useful vision to patients blinded by degenerative retinal diseases."

The implant has not been tested in people, but has been shown to work in rats.

Exercise Reduces Breast And Colon Cancer Death Rates

A study in the May 8 edition of the Journal of the National Cancer Institute reveals that physical activity is linked to lower rates of breast and colon cancer deaths. However, there is not enough evidence to link physical activity to other types of 


Cancer survivors are able to enjoy a longer life due to improved cancer therapies and screenings and they frequently study information on how life factors, such as exercise, can affect their prognosis. Various observational studies and randomized control trials (RCTs) have evaluated the potential impact of physical activity on cancer survivors.

Rachel Ballard-Barbash, M.D., of the Applied Research Program in the Division of Cancer Control and Population Sciences at the National Cancer Institute and her team reviewed 45 articles of observational studies and randomized controlled trials (RCTs), published between January 1950 and August 2011, that examined the relationship between physical activity and cancer mortality and/or cancer biomarkers amongst those who survived the disease. They discovered that the RCTs with biomarker endpoints indicate that exercise is potentially beneficial in terms of the survivors' insulin levels and also reduces inflammation and may improve immunity.

The strongest evidence was found in those who survived breast cancer, followed by those who survived colorectal cancer. Most studies displayed a statistically considerably decreased risk of breast cancer and all-cause mortality related to exercise.

The researchers highlight the fact that due to the diversity of the various studies, specific recommendations in terms of exercise types or timing cannot be made, however, they do confirm that exercise contributes to the cancer survivors' overall safety and to their physical and mental benefits. 

They continue saying that future RCTs should examine various types of exercise, including how obesity, weight loss and cancer treatments may impact the effects of exercise on biomarkers, as well as how exercise may influence comorbidities in cancer survivors.

Edward L. Giovannucci, M.D., ScD, of the Department of Nutrition at the Harvard School of Public Health writes in a linked article that physical activity may prolong cancer survivor's life span and their quality of life, writing:

"Even though direct effects of physical activity on cancer are not definitely proven, given that physical activity is generally safe, improves quality of life for cancer patients, and has numerous other health benefits, adequate physical activity should be a standard part of cancer care."

Children with cerebral palsy may benefit from playing video games

According to a study published online in the Archives of Physical Medicine and Rehabilitation, children with cerebral palsy (CP) may benefit from playing active video games (AVG), such as Nintendo's Wii. 

The researchers found that not only did children enjoy playing AVGs, the games can also help children attain moderate levels of physical activity and could potentially be used in rehabilitation therapy.

Lead researcher Elaine Biddiss, Ph.D., of Toronto's Bloorview Research Institute at Holland Bloorview Kids Rehabilitation Hospital, and the University of Toronto, Canada, explained:

"Active video games (AVG) provide a low-cost, commercially available system that can be strategically selected to address specific therapeutic goals.

While our results did not show that AVG game play can be regarded as a replacement for more vigorous physical activity or muscle strengthening, we found that some games may provide targeted therapy focused on specific joints or movements."

The researchers examined 17 children with CP whilst they played four AVGs: Wii Boxing, Tennis, Bowling, and Dance Dance Revolution (DDR). The team recorded data on energy, muscle activity and motion. Study participants were given a survey in order to mark their level of enjoyment playing the games.

In addition, the team assessed the therapeutic potential of AVG play, the intensity of the physical activity, as well as the practical considerations surrounding the of active video games to promote physical activity. 

The researchers found that although the games were not vigorous enough to build endurance or strength, children with mild CP were able to attain moderate levels of physical activity with games such as Wii Boxing and DDR that require full body movements. 

According to the researchers, AVG play could promote neuroplastic change as they encourage repetitive movements and provide feedback to the player via on-screen game scores and avatars. The children rated enjoyment levels of AVG game play as high, which also improves neuroplasticity.

Wii Boxing may be a good choice for encouraging and training faster wrist movements, the researchers note, which is vital, as children with GP often have difficulty extending their wrists. 

Furthermore, the team found that children with hemiplegia (a form of CP that affects the limbs on one side of the body) who played Wii Boxing or DDR engaged both upper limbs when playing.

Dr. Biddiss said:

"Wii boxing, or similar games, may be an effective motivational environment for encouraging increased movement speed of the hemiplegic limb, in addition to the bilateral use of the limbs, because in-game success is strongly linked to these two metrics."

According to the researchers, the range of motion of the dominant limb was well within the typical norms associated with upper limb movements in able-bodied individuals.

Although further studies regarding safety are required, this study indicates that AVG should be a fairly low impact activity for children with the disorder.

The team found significant differences in the strategies used by the children to succeed in the game. They discovered that children may adapt a movement that reduces physical effort in order to maximize in-game rewards. In a therapeutic setting, it may be necessary to train and provide rewards for appropriate movement styles.

Dr. Biddiss concludes:

"While not a replacement for structured exercise and physical therapy, AVGs may encourage children with CP to be physically active and to practice complex motor activities.

There are many opportunities for further research. Further development and optimization of AVG technologies may usher in a new age in physical rehabilitation where virtual environments provide an arena for neuroplastic change in the comfort of one's home."

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