The possibilities of virtual reality and holographic technologies are no longer limited to entertainment but are helping many industries surmount problems and technical hurdles, notably in the medical domain.
The most advanced hologram technology, which is currently generating a lot of interest, is a three-dimensional projection which can be seen without using any special equipment such as cameras, headsets or glasses. The image can be viewed from any angle, so that when the user walks around the display the object will appear to move and shift realistically.
A hologram is created when a beam of laser light is split in two, with one of the resulting beams shone on an object which is then scattered onto a photographic plate, while the other beam is aimed directly onto the plate. In its pure form, holography needs a laser light for illuminating the subject and for viewing the finished hologram. Nowadays, though, the technology typically consists of a computer-generated replica of a light wavefront projected from a display screen or onto a transparent panel, using an interference pattern to mimic the real-world wavefront from an object—making 2D projections appear 3D.
A typical computer-generated hologram is calculated by algorithms and projected using a spatial light modulator. Some augmented reality (AR) systems use organic light emitting diode (OLED) displays that emit images or clear panels that reflect a projected image.
The next generation holographic displays will enable multiple users to experience the same hologram at the same time, from multiple 3D angles.
These new holographic devices have a significant potential for educational purposes. For example, they could immerse students in an environment they are learning about and allow them to virtually explore and interact with that environment.
The cutting-edge holographic technology can also be used in medical procedures. Cardiologists and cardiac surgeons at Toronto General Hospital’s Peter Munk Cardiac Centre (PMCC) performed the first live medical procedure using real-time holographic imaging developed by an Israeli company. HOLOSCOPE-I provides realistic, spatially accurate 3D in-air holograms. Using these images, cardiologists performed a minimally invasive procedure that replaced a worn-out surgical valve in a patient’s heart. The 3D visualisation technique is a big improvement compared to previous attempts with headsets, which led to eye fatigue and nausea when worn for long periods of time.
The HOLOSCOPE-I technology uses computer-generated holography to build the patient's anatomy from acquired volumetric data and uses points of light in space to represent each volumetric co-ordinate. By employing digital techniques, the image can be manipulated without the restrictions of solid structures, changing shapes and positions while remaining true to the acquired data. The hologram floats in the air in a space in front of the observer at touching distance. The observer can view the image from every angle and perspective. The image can be freely rotated, sliced and even marked. These interactions give the viewer intuitive and unlimited access to all the volumetric data, as if it is the actual object held in the viewer's hand.
Without going as far as live surgical procedures, medical hologram technology allows a complete 3D visualisation of internal organs and body parts. Using this visualisation technology will enable doctors to better examine diseases and injuries in individual patients and will lead to more accurate diagnoses.
The advent of high-speed/high latency 5G networks means that within a few years people could have a holographic phone conversation. At this year’s CES, a US company presented accessories enabling to create 3D holograms, which are viewable in daylight from Android or iOS smartphones equipped with a specialized proprietary chemical polymer lens.
Other advanced fields of science are using holographic microscopes to determine whether life exists on other planets. In digital holographic microscopy, an object is illuminated with a laser and the light that bounces off the object and back to a detector is measured. This scattered light contains information about the intensity of the scattered light and data about how far the light travelled after it scattered. With these two types of information, a computer can reconstruct a 3D image of the object that can show motion through all three dimensions. When applied to spots observed on far away planets, detecting motion helps to distinguish between specks of sand and bacteria.
IEC is preparing standards for this very advanced field of technology IEC Technical Committees 110 prepares standards for electronic displays, including OLED, 3D, holographic as well as flexible screens. It publishes IEC 62341-2-1 on OLED displays for instance, which specifies the essential ratings and characteristics of OLED display modules. It has also issued IEC 62629-41-1, a technical report on 3D and holographic display devices.
IEC TC 76 was set up to produce safety standards for lasers as well as LEDs. One of the TC’s major endeavours is the publication of IEC 60825-1. This standard offers a global classification scheme of laser products according to their safety requirements and emission limits. It is widely used by industry and is viewed as THE reference for any laser equipment by manufacturers, installers and regulators in most countries around the world. For instance, the standard specifies the determination of the nominal ocular hazard distance from the laser source. It also publishes IEC 62471-5 which applies to image projectors, using laser light.
In one of the latest Star War films, Princess Leia had become an emotion inducing hologram. This is close to happening in the real world and IEC Standards are helping these innovative technologies to prepare for mass market applications.