The present invention relates to a scalp treatment device, and more particularly to a hand held scalp treatment device using light for the stimulation of hair growth.
BACKGROUND AND PRIOR ARTLight biostimulation has been recognized as a method for providing stimulation to the scalp which has beneficial and therapeutic effects in terms of stimulating the natural growth of hair. For example, low level laser light is believed to enhance the physiological state of the scalp and encourage hair growth when radiated onto the hair follicles on the scalp. Non-coherent light sources such as light emitting diodes (LED) have also been described in this context.
A number of hand held devices have been designed to exploit the biostimulation effects of light sources such as low level laser and LED in a convenient and portable format.
WO01/60457 describes a hand-held, comb-like device emitting laser beams from laser diodes set in a row centred between two parallel rows of teeth for parting hair. The parting of the hair by the comb teeth is said to improve contact between the laser beam or beams and the scalp to be treated.
WO02/102228 describes a similar device, further including a stepped beam splitting reflector which splits one or more laser beams to allow a laser to simultaneously provide multiple laser beams which are distributed across a segment of an individual's scalp. The beam splitting reflector is mechanically aligned with the laser source and has a zigzag structure that mechanically deflects portions of the laser beam as it passes over the peaks of the beam splitting reflector. The portions of the laser beam form a line of reflected laser beams that project towards the users scalp.
In use, the devices described in WO01/60457 and WO02/102228 emit a narrow strip of parallel light beams from the comb housing onto the scalp. This produces a narrow strip of small, discrete beam spots on the surface under treatment. A problem associated with this pattern of scalp irradiation is that a proportion of the hair follicles present in the surface under treatment may be inadequately irradiated, or not irradiated at all, due to the size and spacing of the beam spots when applied to the scalp. This proportion may be especially significant in areas where the density of hair follicles is high. Repeated passage of the device over the area in question is not a satisfactory solution since there is an overall limit to the amount of laser power that can be applied to a person's scalp before the benefits of laser treatment are outweighed by more harmful conditions such as scalp redness, dryness and peeling.
The object of the present invention is to improve the pattern of scalp irradiation delivered from a hand held scalp treatment device using light for the stimulation of hair growth.
The invention solves the problem of uneven or inadequate scalp irradiation by means of a configuration which channels light through a plurality of hollow tines and spreads the light outwardly from the ends of the tines onto the surface of the scalp to be treated.
U.S. Pat. No. 5,303,722 describes a light comb including a plurality of comb teeth, a device for guiding light from a light source through the comb back into the comb teeth, and a device for radiating the light from the comb teeth. However, the purpose of the device of U.S. Pat. No. 5,303,722 is to selectively irradiate hair to be bleached which is located between the teeth of the comb, and not the scalp. Concave mirrors are used in the tips of the comb teeth to guide light away from the scalp and into the intermediate spaces between the comb teeth.
SUMMARY OF THE INVENTIONThe present invention provides a hand held hair treatment device for the stimulation of hair growth on the scalp, which device comprises:
- a housing which includes a handle portion and a head portion;
- a plurality of hollow tines, each tine having a proximal end affixed to the head portion, a longitudinal length extending from the head portion and a distal end terminating in a tip section;
- a light source disposed within the housing and configured to output light;
- light guide means for channeling the light from the light source through the tines, and
- optical devices which are located at the distal ends of the tines;
- characterised in that the optical devices are configured to spread light which is incident upon them in an outward direction from the distal ends of the tines and onto the surface of the scalp to be treated.
The handle portion may be any structure which facilitates gripping of the device by the user. For example, the handle portion may be formed by an elongated section of the housing, or alternatively may be a strap provided on the housing so that the device may be retained by the hand of the user.
The hollow tines serve to part the hair, enabling light to reach the surface of the scalp. The tines also provide the structures through which light is channeled by the light guide means. The longitudinal lengths of the tines may be formed from any material which enables the tines to perform these functions. Preferably the longitudinal lengths of the tines are formed from a substantially rigid material such as polypropylene, polyethylene, polyester, polycarbonate, polyvinylchloride or other material having similar characteristics.
The individual tines may have a longitudinal length ranging from 0.5 to 5 cm, preferably about 1 to 2 cm.
The individual tines may have a diameter ranging from 0.5 to 5 mm, preferably about 1 to 2 mm.
In an especially preferred embodiment, the tip sections of the tines are formed from a soft and flexible material (such as thermoplastic elastomer, rubber or other material having similar characteristics). This provides a pleasant feel when combing the user's hair or massaging the user's scalp. To this end, it is preferable to round the ends of the tip sections of the tines.
The tines are preferably arranged in a rectangular array of 1 to 3, preferably 2 to 3 rows.
The device may also include further tines in addition to those described above, which do not contain light. Such non-light containing tines may serve to assist in hair parting, scalp exposure, scalp massage or the like.
The device comprises a light source disposed within the housing and configured to output light. Suitable light sources include low power lasers, light emitting diodes or low power semiconductor lasers, capable of delivering light from the visible or infrared spectrum. Examples of preferred light sources are low power lasers having a wavelength ranging from about 600 nm to about 1000 nm, and an intensity ranging from about 1 mW/cm2to about 150 mW/cm2. Such lasers are available commercially as complete modules which are small cylindrical units in which is encased the lasing medium which creates the laser beam and the electronics that control and process the electric current that passes through the lasing medium. Other preferred light sources are light emitting diodes having a wavelength ranging from about 620 to 690 nm, and an intensity ranging from about 1 mW/cm2to about 150 mW/cm2.
The light source may deliver continuous or pulsed light, and may be powered by mains, battery or both. Battery power is advantageous for portability of the device. The battery can be rechargeable or disposable, preferably rechargeable.
Combinations, pluralities or assemblies of any of the above described light sources may also be used. For example, a plurality of laser modules as described above may be disposed in the housing at the proximal ends of the tines.
The light guide means serve to channel light from the housing and through the tines. Preferably the light guide means is constituted by a system of optical fibres which extends from the light source or sources, into the tines and through the tines. Suitable materials used to form the optical fibres may include fused silica, glass or an optical polymer such as polymethylmethacrylate. The optical fibres may extend singly through individual tines or may be provided in bundles.
The optical devices are configured to spread light incident upon them outwardly from the distal ends of the tines onto the surface of the scalp to be treated.
The optical devices will typically include one or more optical components which are capable of spreading light incident upon them in a controlled manner in the desired direction(s), so that a light beam footprint of a predetermined shape is produced on the target surface. By “light beam footprint” is meant the area of the target surface irradiated by the light beam at any moment, or in other words, the intersection of the light beam with the target surface.
Examples of suitable optical components include lenses, optical fibres, mirrors, transparent materials, semi-transparent materials, prisms, reflective coatings, reflecting grooves, beam splitters, light channels or gratings.
Combinations, pluralities or assemblies of any of the above described optical components may also be used.
The optical devices are located at the distal ends of the tines. In order to optimize the pattern of scalp irradiation delivered from the device, it is preferred that the optical devices are located slightly upstream from the actual end points of the tines. This slight spacing ensures that the light which is spread from the distal ends of the tines by the optical devices is not “buried” in the soft scalp surface when the tines are applied to the scalp.
Accordingly, in a preferred tine construction, the optical devices are disposed in a region adjacent to the tip sections of the tines, in the direction of the head portion of the device. An especially preferred tine construction has a substantially rigid longitudinal length and a soft flexible tip section, with the optical device located at the interface between these two component parts.
The optical devices are configured to spread light outwardly from the distal ends of the tines onto the surface of the scalp to be treated. The optical devices serve to deliver an optimal pattern of irradiation to the target scalp surface. By “optimal pattern of irradiation” is generally meant a pattern in which the irradiation is spread over the target surface so that it covers at least 60%, preferably at least 80% of the total area of that target surface. Preferred patterns of irradiation have a regular or substantially regular spatial distribution.
In a preferred construction, the optical devices of the tines are configured so that they produce an array of circular light beam footprints on the target scalp surface. It is preferable to avoid a significant degree of overlap between individual footprints in the array. Accordingly, it is preferred that each individual footprint borders on those footprints which are adjacent to it in the array. The individual beam footprints could alternatively be square, polygonal, or any other shape suitable to deliver an optimal pattern of irradiation.
BRIEF DESCRIPTION OF THE DRAWINGSEmbodiments of the present invention will now be described with reference to the following non-limiting drawings in which:
FIG. 1 depicts a partial schematic sectional view of a hair treatment device of the invention applied to the surface of the scalp;
FIG. 2 depicts a partial schematic top planar view of the device ofFIG. 1 in use, illustrating the pattern of light beam footprints produced by the device, and
FIG. 3 depicts an enlarged schematic sectional view of the distal end of a tine of the device ofFIG. 1 in use on the surface of the scalp.
DETAILED DESCRIPTION OF THE INVENTIONAs shown inFIGS. 1 to 3, ahair treatment device10 has ahousing11 formed from a handle portion12 (shown in part) which is connected to ahead portion13. Two parallel rows of fourhollow tines14 are connected to headportion13 and project downward fromhead portion13. Eachindividual tine14 has aproximal end14aaffixed tohead portion13, a rigidlongitudinal length14bextending fromhead portion13, and adistal end14c. The distal ends14cof the tines terminate in rounded softflexible tip sections15.Lens assemblies16 are interposed betweenlongitudinal lengths14bandflexible tip sections15.
In use, thedevice10 is applied to an area ofscalp17, with theflexible tip sections15 applied to the surface of thescalp18. A system offibre optics19 channels light from a light source (not shown) through thehandle portion12, into thehead portion13, and down through each of thetines14 towardslens assemblies16. Light incident uponlens assemblies16 is spread bylens assemblies16 in an outward direction from the distal ends14coftines14 onto the surface of thescalp18. The light emerging from lens assemblies16 (shown as21 onFIG. 3) produces an array of circular light beam footprints (shown as20 onFIG. 2) on thesurface18.