Ultrasound eradication of head lice
Head lice infestation is a common problem in children. Current treatments involve fine-tooth combing and administration of pesticides, which are however unpleasant and difficult to administer. With this in mind, the 'A novel integrated ultrasonic brush and sonically activated lotion to provide a full system approach to the eradication of the European head louse menace' (Clearbrush) project developed a device that consists of a special brush, designed to vibrate at a certain mode, and a special lotion, which immobilises, penetrates and kills eggs while lubricating their removal. The consortium focused on the development and integration of the Clearbrush system components. The amplitude of the ultrasonically activated bristles were investigated so that the forces at the hair surface destroy the lice eggs with no damage to the hair or scalp. The bristle construction material was also researched and it was found that certain metals, in particular stainless steel, aluminium and titanium, are most efficient in transferring ultrasound. As a result, the Clearbrush bristles were constructed from stainless steel. The active lotion properties were optimised to maximise the transfer of ultrasound waves and to effectively kill lice while simultaneously lubricating the hair to facilitate their removal. Study results showed that, compared to silicone-based lotions, certain aqueous emulsions have enhanced lubricating properties and are more efficient conductors of ultrasound. Project partners decided that for optimal system performance the active lotion should be dispensed by hand into the hair prior to applying the Clearbrush unit. The Clearbrush system was clinically validated on human subjects showing an 82 % lice eradication rate compared to 70 % of benchmark treatments. Minimal aesthetic and ergonomic improvements to the Clearbrush unit were planned prior to its European marketing.
