How to buy Headlights
Surgical Headlights are worn by surgeons and dentists to help reduce the reliance on cumbersome overhead lighting systems. The main problem with overhead lights is that in order to achieve optimal lighting during a surgical procedure, they need to be readjusted and re-aimed every time the surgeon moves from one part of the operating field to another. This may happen several times during the course of an operation and can be very frustrating for the medical professional.
Furthermore, it is difficult to illuminate certain parts of the body, especially deeper cavities, using overhead lights. Headlights have the advantage that they directly aim light wherever the surgeon is working and can be combined with other items such as loupes or a camera. On the down side, some surgeons and dentists may find wearing a headlight restrictive or uncomfortable. This was certainly true with the old generation of heavy headband mounted headlights, which are attached to a light source with a light cable. Nowadays there are newer lower profile headlights which do not even need a cable!
TYPES OF HEADLIGHTS
Fibre Optic Lights
The fibre optic headlight consist of a light box (which emits the light), a fibre optic cable of variable length (which transmits the light) and a headlight (which shines the light onto the subject).
There are a variety of light boxes of different shapes and sizes. The basic feature is that they have a lamp (either a halogen or xenon), which emits light through a rotating turret with ports that fit to a variety of different commercially available fibre optic cables. This means the light source can be used in conjunction with different pieces of equipment including headlights, fibre optic cables, microscopes and endoscopes etc.
Xenon light sources consist of a xenon lamp powered by electricity. It uses ionized Xenon gas to produce a bright white light that closely mimics natural daylight. The colour of the light varies with the temperature measured in Kelvin and usually is around the 5500 to 6000°. As a general rule, the higher the temperature the whiter the light.
The power rating for commercially available Xenon light sources varies between 100 and 300 watts. The lamp life for a Xenon bulb varies between 500 to 1000 hours and is much longer than halogen bulbs (80 to 100 hours). Halogen lamps also produce a more yellow light. Replacement Xenon lamps can be expensive and this must be factored into the cost.
Fibre optic cable
An optical fibre cable is a cable containing one or more optical fibres. The optical fibre elements are typically individually coated with plastic layers and are contained in a protective tube. The function of the fibre optic cable is to transmit light from the light box to the headlight. The cable varies in length and is an important consideration when choosing a fibre optic system. Fibre optic cables can be damaged especially during heavy use and these may appear as specks in the light circle. Depending on how often they are used usually determines how often they need to be replaced, which also should be factored in to your budget.
This is the functional end of the fibre optic system which is used to shine the light onto the subject. Fibre optic headlights are usually headband mounted and can be combined with accessories such as loupes or even cameras. A good headlight will have the facility to aim the beam, adjust the spot size and even focus the light properly, to give a good depth of vision. Since headlights can get hot a suitable heat sink should also incorporated.
Non Fibre Optic Lights
A LED lamp is a type of solid state lighting (SSL) that utilizes light-emitting diodes (LEDs) as a source of illumination rather than electrical filaments or gas. LED headlights require much less power and therefore can be run on batteries which can be incorporated onto the headband or clip on battery pack. This means that the surgeon/dentist does not need to be restricted by a fibre optic cable attached to a light source. LED lights are rapidly developing and becoming more powerful and some units are 50,000+ lux (see below). LED lights tend to be quite lightweight and therefore can be headband mounted or can be clipped on to spectacle frames.
||1 = LED Lamp |
2 = Heat sink
3 = Switch
4 = Pivot Joint
5 = Charging jack
6 = Adjustment buckle
7 = Battery Pack
8 = Brow protecting pad
9 = Loupe (optional)
Things to consider when buying a headlight
This is especially important during lengthy procedures. The weight of the unit is important but the weight distribution is also a factor. A low profile lightweight system will allow the user to have an unrestricted view of the operating site. The material used is also important and leather material may be more comfortable than the traditional plastic materials used in headbands.
Some surgeons may find headbands restrictive, in which case, a clip-on light is an alternative (see below). The length of cable, if selecting a fibre optic light source, is also an important consideration and for surgeons/dentists who find fibre optic cables restrictive, a battery operated unit is a useful alternative. These will usually be LED powered lights.
As mentioned, most units are headband mounted. The advantages with headbands are that the weight is evenly distributed around the head; headlights can be combined with loupes and if high magnification is not required a simple magnifier can be incorporated into the mechanism. Clip-on lights are an alternative to headbands and can be clipped onto spectacle frames. Although these are usually lightweight, weight may bear on the bridge of the nose, especially if combined with a loupe system.
Headband mounted LED
light Clip on light
Most headlight systems allow the size of light circle to be adjusted, which is important if the user wants to adjust the area that is to be illuminated. Some headlights also have optics that allow focusing of light, which has implications for depth of vision.
An advantage of light boxes is that the intensity of the light can also be adjusted.
Colour of light
The colour of the light needs to be taken into account. For a brighter whiter light, a Xenon lamp and LEDs lamps are better than halogen.
The intensity of the light is measured