Helping prevent photosensitive epilepsy


Mark Hodgetts TV-Bay Magazine
Read ezine online
by Dr Mark Hodgetts
Issue 79 - July 2013
Photosensitivity is sensitivity to flickering or intermittent light stimulation and visual patterns. It is a condition which affects approximately one in four thousand people. A number of young people have this sensitivity but have not yet had a seizure and therefore have not been diagnosed with the condition. At this age, seizures are terrifying for the individual, deeply distressing for families and friends and profoundly life changing for all concerned. As well as emotional distress, seizures also carry inherent and situational risks which often include physical harm and can, in extreme cases, lead to loss of life. Once triggered, three quarters of patients remain photosensitive for life.

Both natural and artificially occurring light may trigger seizures, but one of the most common triggers for photosensitive epilepsy is the domestic television set. The television set does not cause the photosensitive epilepsy, but watching it can and does trigger seizures in people where the condition is present even though it may be dormant. Other triggers include stroboscopic lighting, illuminated patterns and other forms of stimulation such as video games, digital signage, digital cinema, computer displays and web content.

There are three main stimuli that can trigger photosensitive seizures, bright flashing which involve rapid changes in luminance, colour changes to and from a saturated red, and certain spatial patterns consisting of regular light and dark features. Photosensitive individuals may be sensitive to different levels of stimulation and to all, or just some of the stimuli.
In the UK, in response to a Pot Noodles advert in 1993 which was irrefutably found to have caused a number of photosensitive epileptic seizures, the then Independent Television Commission (ITC) introduced its Guidelines for Flashing Images and Regular Patterns.

In December 1997 a childrens Pokemon cartoon episode in Japan produced 685 admissions to hospital. 560 cases were shown to have had proven seizures, triggered by a four second sequence of alternating saturated red and blue light used in the programme. Of those patients, 76% had had no previous history of seizures. This led to the adoption of Guidelines for Flashing Images and Regular Patterns in Television in Japan.

In December 2003, the UK Governments Office of Communications (Ofcom) inherited the duties of the ITC in the UK. They published a Guidance Note for Licensees on Flashing Images and Regular Patterns in Television as part of the licensing conditions for UK broadcasters.

However, even with these guidelines in place, events can still happen. In 2008 the broadcast of a promotional video launching the new logo for the London 2012 Olympics as part of an early morning news program led to 30 reported seizures. Unfortunately this material had not been checked for compliance with the UK Guidelines prior to broadcast. When it was checked on a HardingFPA system, significant levels of non-compliant flashing were detected.

With the march of technology, new sources of imagery, and continual market demands for exciting new visual styles and high impact effects, there is an increasing risk to the public of experiencing a photosensitive epileptic seizure. In response to this and following reports of seizures triggered by hand held video games, in 2008 John Penrose a member of the UK parliament started a campaign to extend the UKs Ofcom Guidelines to cover other sources of video imagery including Video Games, DVDs, digital signage and web based content.

Cambridge Research Systems has developed the market leading Harding FPA Broadcast Flash and Pattern Analyser using sophisticated image processing technology. It analyses material frame-by-frame, in real time or faster, directly from most video sources. It verifies compliance with UKs Ofcom, ITC or Japanese NAB guidelines and warns of any sequences likely to precipitate photosensitive epileptic seizures (PSE), while promoting a safer television viewing environment.

The Harding FPA can be used to check material well in advance of transmission, even during production, so that you can be confident about meeting deadlines and compliance. The information it provides allows greater creative flexibility in adjusting failing sequences to meet both creative and regulatory requirements and the system is available in forms which integrate fully into your workflow.

Visit www.hardingfpa.tv to find out more.


Tags: iss079 | photosensitivity | photosensitive epilepsy | prevention | guide | Mark Hodgetts
Contributing Author Mark Hodgetts

Read this article in the tv-bay digital magazine
Article Copyright tv-bay limited. All trademarks recognised.
Reproduction of the content strictly prohibited without written consent.

Related Interviews
  • Guided Tour of the Polecam Stand at BVE 2016

    Guided Tour of the Polecam Stand at BVE 2016

  • Guided tour of the Global Distribution Stand at BVE 2016

    Guided tour of the Global Distribution Stand at BVE 2016

  • Guided tour of the Holdan Stand at BVE 2016

    Guided tour of the Holdan Stand at BVE 2016

  • PAG talk about flying with batteries at IBC 2014

    PAG talk about flying with batteries at IBC 2014

  • TMD talk workflow on BroadcastShow LIVE at IBC 2013

    TMD talk workflow on BroadcastShow LIVE at IBC 2013

  • Triveni Digital at NAB 2012

    Triveni Digital at NAB 2012


Related Shows
  • Talking Streaming with Stream UK: BVE Day 3

    Talking Streaming with Stream UK: BVE Day 3


Articles
An Obituary to Timecode
Bruce Devlin - new A stoic and persistent character that stubbornly refused to change with the times, Timecode has finally passed on, but no-one has noticed. A long-lasting industry veteran, Timecode was brought into this world at an uncertain date in the late 1960s due to the needs of analogue tape workflows and the demand for synchronisation between audio and video devices. A joint activity between SMPTE and the EBU led to the work on Time and Control codes starting its journey to standardisation in the early 1970s.
Tags: iss134 | timecode | smpte | ebu | edit | Bruce Devlin - new
Contributing Author Bruce Devlin - new Click to read
Sony HDC-4800 Review
Andy McKenzie First announced at NAB 2016, the Sony HDC-4800 is a studio camera system capable of shooting 4K/UHD at up to 8x or full HD at up to 16x. With a price point upwards of £250,000 it is a very high-end product with a wide feature set. In Sony's own words, "This is the future of live production, designed to satisfy the storytelling aspect of modern sports production.” Deliveries began in mid 2017 and, after careful preliminary evaluation, we invested in several systems for our hire fleet ahead of the FIFA World Cup in Russia.
Tags: iss134 | review | hdc-4800 | sony | finepoint | Andy McKenzie
Contributing Author Andy McKenzie Click to read or download PDF
State of the Nation - November 2018
Dick Hobbs - new There is an interesting seminar called Size Matters at the KitPlus Show – organised by the publishers of this fine magazine – at MediaCityUK in Salford on 6 November. It’s a talk by cinematographer Alistair Chapman on the way that camera technology is changing, and in particular the size of the electronic device which creates the image is growing.
Tags: iss134 | cmos | 35mm | AJA | Arri | Blackmagic | Canon | Datavideo | GoPro | Grass Valley | Hitachi | Ikegami | JVC | Kinefinity | Nikon | Panasonic | Red | Sony | jpeg2000 | Dick Hobbs - new
Contributing Author Dick Hobbs - new Click to read or download PDF
AI in Media and Entertainment
David Candler Artificial Intelligence (AI) is a term appearing everywhere these days. What is happening in media and entertainment (M&E) that makes the industry ripe for AI? In other words, why does the M&E industry need AI?
Tags: iss134 | AI | wazee | David Candler
Contributing Author David Candler Click to read or download PDF
Shedding Light on the Blackmagic Pocket Cinema Camera 4k BMCPP4K
Garth de Bruno Austin “What is it about light that has us craving it?” Is the question asked in the opening seconds of Garth de Bruno Austin’s latest short, The Colour of Light. Exploring this natural, human need as well as our innate desire to control it, Garth’s film showcases everyday people going about their lives in differing degrees of luminance, whether that be an artificial streetlight or a natural morning sunrise.
Tags: iss134 | blackmagic | cinema camera | 4k | cpp4k | Garth de Bruno Austin
Contributing Author Garth de Bruno Austin Click to read or download PDF