1. Field of the Invention
The invention relates to application of a substance to a patient's skin, whereby the substance is an ascorbic acid, lidocaine, collagen, or other type of skin treatment substance.
2. Description of the Related Art
It is known that an electrical pulse applied to the skin is useful in order to increase the absorption of a substance previously applied to the skin, whereby this technique is known as electroporation. Such a substance to be applied to the skin may be a liquid, a gel, a lotion, or a cream, for example.
It is also known that a mechanical pulse can be applied to the skin at the same time as the electrical pulse, in order to increase the effectiveness of skin absorption.
It is desired to provide an apparatus and a method to increase the absorption of a substance to be applied to the skin, in order to obtain an increased (e.g., moisturizing) affect of the substance applied to the skin, as well as to obtain a fairly even absorption of the substance to the skin.
The present invention is directed to an apparatus and a method for enhancing the absorption of a substance to be applied on the skin.
According to one aspect of the invention, there is provided an apparatus for enhancing absorption of a substance to be provided on a region of a patient's skin. The apparatus includes a head portion having at least one electrode that outputs bursts of electronic pulses to the patient's skin, whereby the electronic pulses are generated by an electronic pulse generator. The apparatus also includes a mechanical vibrator that generates mechanical vibrations to be applied to the patient's skin at the same time the electronic pulses are applied to the patient's skin. The bursts of electronic pulses are output at a first burst rate, and the mechanical vibrations are output as bursts of vibrations at a second burst rate.
According to another aspect of the invention, there is provided a method of transdermal drug delivery to be provided to a patient's skin. The method includes applying at least one burst of electronic pulses to the patient's skin at a first burst rate. The method also includes applying at least one burst of mechanical vibrations to the patient's skin at a second burst rate, in which the mechanical vibrations are applied to the patient's skin at the same time the electronic pulses are applied to the patient's skin.
The foregoing advantages and features of the invention will become apparent upon reference to the following detailed description and the accompanying drawings, of which:
Preferred embodiments of the invention will be described in detail below, with reference to the accompanying drawings.
U.S. Pat. No. 7,376,460, which is incorporated in its entirety herein by reference, describes a method and an apparatus for skin treatment of a patient. In the '460 patent, mechanical vibrations are continuously applied to a patient's skin, while electronic bursts of pulses are applied to the patient's skin at the same time. The mechanical vibrations are applied at a vibration rate that is an integer multiple or submultiple with respect to the burst rate of the electronic pulses applied to the patient's skin.
Experimental results performed by the inventor have determined that applying the mechanical vibrations to a patient's skin in pulse bursts at a mechanical vibration burst rate, at the same time the electrical pulses are applied to the patient's skin, enhances the skin absorption effect of a drug that is provided to the skin while these mechanical and electrical vibrations are also being applied to the skin.
The electrical pulses are preferably applied to the patient's skin by an array of electrodes that are provided on a head of a skin treatment device, such as a hand-held probe.
As described in U.S. Pat. No. 7,376,460, the use of a continuous stream of mechanical vibrations at the same time that the electrical pulses are applied to skin, and at a same or nearly the same frequency as the burst pulse rate, results in a patient having a greater tolerance to the strength (current and voltage) of the electrical pulses applied to the patient's skin. For example, using a electrical pulse burst rate of 50 Hz (that is the rate between bursts of pulses), mechanical vibrations may be provided at a range of between 40 to 60 Hz at the same time that the electrical pulse bursts are applied to the skin, to provide a “masking effect.” U.S. Pat. No. 7,376,460 describes that utilizing mechanical vibrations at or around (e.g., +/−10% of) the fundamental frequency of the electrical pulse burst rate, at or around the first harmonic of the electrical pulse burst rate, at or around the second harmonic of the electrical pulse burst rate, and/or at or around the third harmonic of the electrical pulse burst rate, gives the patient a “good sensation” so that he/she can tolerate a higher strength of electrical pulses being applied to his/her skin at the same time. Thus, for a 50 Hz electrical pulse burst rate, mechanical vibrations may be applied to the patient's skin at the same time, with the mechanical vibration rate being either 40 to 60 Hz, 90 to 110 Hz, 140 to 160 Hz, and/or 190 to 210 Hz. By having mechanical vibrations applied to the patient's skin at the same time that the electrical pulse bursts are applied to patient's skin, the patient's discomfort level caused by the tinging sensation of the electrical pulses is lessened (e.g., masked somewhat).
In a first embodiment of the invention, the mechanical vibrations are provided in bursts of mechanical vibrations, as opposed to a continuous stream of mechanical vibrations.
The mechanical vibrations in each burst of mechanical vibrations need not be at an integer multiple or submultiple with respect to the bursts of electronic pulses applied to the patient's skin at the same time. For a 100 Hz mechanical pulse burst rate having 33 KHz mechanical vibration pulses in each of the bursts, one obtains a frequency spectrum of a 33 KHz carrier with harmonics of 100 Hz. That is, the mechanical vibration frequency spectrum for this example corresponds to a center frequency at 33 KHz, a first harmonic at 33.10 KHz and 32.90 KHz, a second harmonic at 33.200 KHz and at 32.800 KHz, a third harmonic at 33.30 KHz and 32.70 KHz, etc.
The effect of applying the probe to the skin is that the skin vibrates due to the electrical pulses applied by way of the array of electrodes (for example, the array of electrodes shown in FIGS. 2A and 2B of U.S. Pat. No. 7,376,460), and also due to the mechanical pulses applied to the patient's skin at the same time. The electrical pulses are preferably applied at a fixed frequency between 200 and 10,000 Hz (optimally at a frequency value between 2,000 to 3,000 Hz), and are grouped in burst of pulses (e.g., each burst may correspond to 100 to 1000 separate pulses that have opposite polarities with respect to adjacent pulses in the same burst of pulses). The ON time of each burst is a fixed value between 5 to 50 milliseconds, and the OFF time between two consecutive bursts is a fixed value between 5 to 50 milliseconds (the burst ON time can be 10 milliseconds and the OFF time between consecutive bursts can be 10 milliseconds).
As described above, the electrical pulses applied to the skin by way of the electrodes can be exponential pulses with peak-to-peak voltage of 160 V at a fixed frequency between 2,000 to 3,000 Hz. One way of providing such electrical pulses is by an electrical structure that corresponds to a pulse generator 400 as shown in
Along with the electrical pulses applied to the skin, a mechanical vibration is also provided to the skin in the first embodiment in order to increase the absorption of a substance that is applied on the skin.
The absorption effect is enhanced by the simultaneous increase of transpiration, whereby the absorption effect is greatest when the mechanical vibration is synchronized in phase and in frequency with the electric pulse application. Thus, in the example discussed above, while the electrical burst of pulses (at 2,200 Hz) are provided to the skin at a burst ON/OFF frequency, e.g., 50 or 100 Hz, by way of an electrode array, the skin is also mechanically vibrated at the same frequency, e.g., 50 or 100 Hz, by way of the vibrating plate, but whereby the mechanical vibrations are output as bursts of pulses at a high vibration rate, such as 33 KHz. The mechanical burst vibration and the electrical burst application can be provided in phase with respect to each other, in order to increase the skin absorption effect.
Thus, in the example discussed above, while the burst of electrical pulses are provided to the skin by way of the electrode array, the skin is also mechanically vibrated at the same frequency by way of the vibrating plate that provides bursts of mechanical vibrations to the patient's skin. The mechanical vibration and electrical pulse application can be provided in phase with respect to each other, in order to increase the skin absorption effect.
Moreover, the absorption effect is further enhanced when the mechanical vibration is applied orthogonal to the surface of the skin. While Applicant does not intend to be tied down to any particular theory of operation, one possible explanation of the physical phenomena of one or more embodiments of the present invention is that, while the electrical pulses “stretch” the skin, thus increasing periodically the diameter of the pores of the skin, at the same time the mechanical vibration “pumps” the substances (gel, liquid or cream) inside the skin (through the opened pores). The mechanical and electrical synchronization achieves the effect that the “pumping” action (due to the mechanical stimulation of the skin) takes place at the same instant in time that the pores are at their maximum “open” diameter (due to the electrical stimulation of the skin).
The apparatus according to a first embodiment the present invention includes a probe having two main parts:
A) a handle containing a power source (e.g., batteries) and a pulse generator; and
B) a vibrating head containing components for generating the bursts of mechanical vibrations and also containing an array of electrodes (see FIG. 3 of U.S. Pat. No. 7,376,460, for example, which shows one possible probe head structure for providing mechanical vibrations and electrical pulses to a patient's skin, whereby these are provided in bursts of vibrations and pulses in the first embodiment of the present invention).
The vibrating head, in a preferred configuration of the first embodiment, includes a D.C. electrical motor for generating vibrations to the skin, and a piezoelectric transducer.
Different embodiments of the present invention have been described according to the present invention. Many modifications and variations may be made to the techniques and structures described and illustrated herein without departing from the spirit and scope of the invention. Accordingly, it should be understood that the apparatuses described herein are illustrative only and are not limiting upon the scope of the invention. For example, the frequency of the mechanical vibration and the frequency of the bursts of electronic pulses may be the same, as described above with respect to several different embodiments, or they may be an integer multiple or submultiple of each other. For example, an electronic pulse burst frequency of 50 Hz may be utilized together with a mechanical vibration burst frequency of 100 Hz (each having mechanical and electrical pulses provided in each burst at a rate of between 20 KHz to 50 KHz, for example), and still one would achieve an effect of increased absorption and decrease in skin sensitivity (e.g., lowering of the pain) to the patient. Alternatively, an electronic burst frequency of 200 Hz may be utilized together with a mechanical vibration burst frequency of 100 Hz, and still one would achieve an effect of increased absorption and decrease in skin sensitivity. Also, the plate on which the electrodes are disposed on the probe in certain embodiments may be a sterilized disposable part (e.g., removed from a sterilized container and then affixed to the head of the probe). In this implementation, when one is finished treating a patient, the disposable plate is removed from the probe and discarded, and then a new sterilized plate is affixed to the probe (with the electrodes provided thereon) in order to treat another patient. By such an implementation, this greatly reduces the possibility of contamination between different patients, since the portion of the probe directly in contact with each patient is discarded after treatment of each patient.
This application claims the benefit under 35 U.S.C. §119(e) to U.S. Provisional Application No. 61/171,539, filed on Apr. 22, 2009, which is incorporated by reference herein in its entirety.
Number | Date | Country | |
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61171539 | Apr 2009 | US |