Abstract:
A device and method to cause hair loss or prevent or inhibit hair growth. The invention uses plasma (ionized gas) that is generated by flowing gas in close proximity to an electrode that has a high potential applied to it. The result is a stream of charged gas particles that are directed to the skin that contains hair. The flowing stream of gas is held above the surface of the skin. Additionally, a grounded conductive material is affixed to the skin to dissipate any charge buildup on the skin and focus the plasma.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to U.S. Provisional Patent Application No. 61/096,994, entitled “Device and Method to Prevent Hair Growth,” filed on Sep. 15, 2008, which is herein incorporated by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to a device and method to cause hair loss or prevent or inhibit hair growth. More specifically, the invention uses a stream of charged gas particles (i.e., plasma) that are directed to the skin that contains hair. 
     2. Description of the Prior Art 
     The principal methods presently used for inhibiting hair growth involve the use of lasers, electrolysis techniques, waxing, or chemical depilatories. These techniques involve some pain, can cause permanent damage to the skin, have high costs, are time consuming, and demand a fair degree of expertise in their application. 
     What is needed is a simple, safe, and cheap device and method for the removal of hair. However, in view of the prior art considered as a whole at the time the present invention was made, it was not obvious to those of ordinary skill in the art of hair removal how the identified needs could be met. 
     SUMMARY OF INVENTION 
     In view of the foregoing problems, the novel invention discloses a simple, harmless, and economical apparatus and method for the prevention of hair growth. 
     The method to cause hair loss or prevent or inhibit hair growth includes the steps of introducing a substantially continuous electric field, in the form of non-thermal plasma (i.e., ionized gas) generated by a DC voltage applied to an electrode, to the surface of a biological structure. Specifically, a DC voltage is applied to an electrode creating a first potential. A gas source supplies a stream of gas past the first potential creating a second potential, the second potential being either positive or negative plasma. The second potential is applied to a biological structure for the necessary time and at the necessary distance to achieve hair loss or inhibit/prevent growth. A means for controlling the flow of gas, run time, voltage, and current is provided. Multiple second potentials may be applied simultaneously or in series to expedite or improve the process. A conductive material that is grounded and in contact with the biological structure is used to dissipate any charge buildup and to focus the plasma to the target tissue. 
     The apparatus is a hollow body with a gas source in fluid communication. Gas enters the first end and exits the second end of the hollow body. The gas flow is controlled by a flowmeter. An electrode connected to a power supply is positioned at the second end of the hollow body. When the electrode is energized, an electric field is created. As the gas flows past the electric field, the gas becomes ionized (i.e., plasma). The plasma exits the hollow body and is directed to a biological source, resulting in hair growth prevention/inhibition or loss. A grounding device may be used in conjunction with the apparatus to dissipate any charge buildup. The grounding device is grounded and in electrical contact with the biological source. The grounding device may be connected to a material having high impedance. The voltage, current, and run time of the apparatus is controlled by computer interface program such as LabVIEW®. For accurate targeting, the hollow body has a pointing device attached to it and is mounted to a manipulator arm. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a fuller understanding of the invention, reference should be made to the following detailed description, taken in connection with the accompanying drawings, in which: 
         FIG. 1  is a perspective view of the plasma pen; 
         FIG. 2  is a perspective view of the ground ring; 
         FIG. 3  is perspective view of the plasma pen and ground ring; 
         FIG. 4  is a perspective view of the plasma pen system; 
         FIG. 5  is a perspective view of the plasma pen system as applied to a biological surface; 
         FIG. 6  shows photographs of animals treated with plasma; and 
         FIG. 7  shows photos of animals treated with plasma. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     In the following detailed description of the preferred embodiments, reference is made to the accompanying drawings, which form a part hereof, and within which are shown by way of illustration specific embodiments by which the invention may be practiced. It is to be understood that other embodiments may be utilized and structural changes may be made without departing from the scope of the invention. For example, charge from many sources can be applied to achieve the same effects. These can include but are not limited to: corona charge, DC plasma, AC plasma, RF plasma, plasma formed from any gas (including air), plasma formed from any mixture of two or more gasses, and electrospray technology. 
     The present invention includes a method and associated apparatus for the delivery of a potential which results in hair loss or prevents or inhibits hair growth. The method and apparatus in accordance with the present invention are effective in using an electrical field to adjust the potential of a target surface. 
     The plasma used in this invention is a nonthermal helium (He) plasma that is generated by passing high purity He through a conductive ring that is at a constant DC voltage. The resulting ionized gas (i.e., plasma) is directed by the He flow to the target tissue which is skin. It was determined in mouse skin that applying the plasma treatment to the shaved flanks of mice for different times completely stopped the regrowth of hair. Similar results were found when either a positive polarity electrode or negative polarity electrode were used to create the plasma. There was no physical contact between the plasma pen and the target tissue. In fact, the plasma generating device was several centimeters (0-20 cm) away from the skin during treatment. Further, there was no observed stimulation of muscles in the mice. This was due to the fact that the He plasma treatment supplied very low levels of current (microamps). 
     Referring now to  FIG. 1 , electric field generation device  100  includes tube  105  having inner channel  107 . Tube  105  is approximately 15 cm long and the diameter of inner channel  107  is approximately 1 cm. Annular electrode  110  is positioned substantially at the opening of tube  105 . Tube  105  is connected to a high-voltage and low-current direct current power supply. In this embodiment, an electric potential of about +8 kV or −8 kV is applied to electrode  110  depending on the desired polarity. A stream of ultra high purity helium is passed through inner channel  107  and electrode  110  at a rate of 15 l/min. 
     As shown in  FIGS. 2 and 3 , sample plate  120  is used in conjunction with electric field generation device  100 . Sample plate  120  includes inner chamber  122  and outer chamber  124 . Inner chamber  122  is adapted to hold a biological structure. Outer chamber  124  is adapted to receive grounding ring  126  which is connected to a ground through wire  128 . Grounding ring  126  and wire  128  can be made from any conductive material as is known in the art. In another embodiment, wire  128  passes through high impedance. Grounding ring  126  can be placed directly on the surface of the biological structure. For example, for preventing hair growth, grounding ring  126  may be temporarily placed directly on the skin with a mild adhesive. 
     Device  100  is a hollow tube about the size of a pen, as depicted in  FIGS. 4 and 5 . A first end of tube  100  has gas inlet  10  that is connected to a gas source by flexible plastic hose  11 . Gas hose  11  has inline flowmeter  12  used for precise control of the gas flow rate. A second end of tube  100 , where gas escapes, houses annular electrode  110  (a stainless steel washer). Electrode  110  is connected to a high voltage low power supply through rubber jacketed wire  14  positioned along the outside of tube  100 . The power supply is controlled remotely by computer interface program LabVIEW®  15 . Interface  15  is used to control treatment time and to monitor voltage and current values leaving the high voltage generator. Interface  15  allows the user to set the experimental run time, operating voltage, and maximum current output. The power supply and computer interface are mounted in transportable metal box  16 . Box  16  contains flowmeter  12 , all electrical connections, and gas hose  11  connections. Tube  100  contains a pointing device (not shown) that allows the user to identify the center of plume of charges that are emitted from the device. In addition, the tube is mounted to manipulator stand  18  that allows the apparatus to be steadily positioned in four dimensions (x, y, z, and φ). The fourth dimension refers to an angular movement with respect to any of the x, y or z planes. Ground source  19  is positioned around treatment field  20  to prevent the buildup of charge on areas of the body that are not intended for treatment. 
     Originally, helium plasma work in tissues was initiated for the purpose of delivering DNA to the cells of skin and tumors. However, unexpected results occurred; particularly, the absence of hair growth that resulted in the skin that was treated with plasma. 
     The initial experimental evidence for this invention was obtained by treating  10  groups of female C57Bl/6 mice. Each mouse in the study had its left flank shaved prior to treatment. The treatment groups were as follows: no treatment, injection of DNA alone, 4 groups treated by Injecting of DNA followed by either 2, 5, 10, or 20 minutes of positive polarity plasma treatment, and 4 groups treated by injecting DNA followed by either 2, 5, 10, or 20 minutes of negative polarity plasma treatment. During the experiment, the plasma pen was maintained at a constant distance of 3 cm from the skin. All DNA was injected as a 50 microliter volume containing 100 micrograms of gWiz-Luc plasmid (encoding luciferase). All DNA injections were performed intradermally using a 25 gauge needle mounted on a 1 cc syringe. This study was originally designed to deliver DNA to the dermis. These experiments were successful and are part of another disclosure. However, during the 40 day follow up period to check for expression, it was observed that no hair regrew in animals that were treated with plasma of either polarity. 
       FIG. 6  shows photographs of animals from three treatment groups on Day 0 (day of treatment) and Day 40 (termination of experiment). Animals that received no treatment are labeled as A, animals that received 20 minutes of positive plasma after DNA injection are labeled as B, and animals that received 20 minutes of negative plasma treatment after DNA injection are labeled as C. The shaved flanks of animals in the no treatment group (A—Day 0) compared to the total regrowth of hair in the same 4 animals at day 40 (A—Day 40). In contrast, animals that received 20 minutes of positive plasma treatment showed minimal hair regrowth from their shaved Day 0 state (B—Day 0) and the 40 day end point of the observation (B—Day 40). Similarly, the animals treated with negative plasma for 20 minutes showed a lack of hair regrowth over the 40 day follow up period (C—Day 0 versus C—Day 40). This data confirms that the absence of hair growth is a result of plasma treatment. 
     Following the initial unexpected results, additional experiments were conducted without injecting the mice with DNA.  FIG. 7  shows photographic data of animals from three treatment groups on Day 0 (day of treatment) and Day 30 (termination of experiment). Animals that received no treatment are labeled as No Treatment. The other two treatment groups received either 20 minutes of positive plasma treatment or 20 minutes of negative plasma treatment. In contrast to the animals shown in  FIG. 6 ,  FIG. 7  animals did not have any DNA injected into their respective treatment sites. In each photo in  FIG. 7 , the same animals are shown on Day 0 and Day 30. The animals are shown in the same order, left to right, to facilitate comparison. All Day 0 data shows animals with shaved left flanks that received no treatment. On Day 30 the hair in the flanks of animals in the no treatment group was almost completely regrown. This growth occurred between day 21 and day 30. In contrast, animals that received either 20 minutes of positive plasma treatment or 20 minutes of negative plasma treatment showed minimal hair regrowth on Day 30. 
     It will be seen that the advantages set forth above, and those made apparent from the foregoing description, are efficiently attained and since certain changes may be made in the above construction without departing from the scope of the invention, it is intended that all matters contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.