CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority from US Provisional Patent Application 61/840,540, filed June 28, 2013, which is assigned to the assignee of the present application and is incorporated herein by reference.

FIELD OF THE APPLICATION

The present invention relates generally to skin care, and specifically to devices and techniques for applying skin-care cream.

BACKGROUND OF THE APPLICATION

Many skin-care creams are available for application to the face, including anti- aging creams, antioxidant creams, anti-wrinkle creams, serum-infused creams, cellular regeneration creams, and moisturizing creams. Some creams combine more than one of these functions.

SUMMARY OF THE APPLICATION

In some embodiments of the present invention, a set of skin-care units is provided for applying one or more skin-care treatments to skin of a subject, such as skin of a face of the subject. Typically, the skin-care units are configured to apply a skin cream to the skin of the subject.

For some applications, the skin-care units are used sequentially to treat the skin, such as in accordance with the following treatment regimen:

• the subject uses a skin-care unit that defines a skin-abrasion lower surface to remove dead cells of a stratum corneum of the skin, in order to prepare the skin for application and better absorption of a skin cream;

• after removing the dead cells, the subject applies a skin cream that comprises ions;

• after applying the skin cream, the subject uses another skin-care unit to apply iontophoresis to the skin, in order to drive the skin cream into the skin; and

• before or after applying the iontophoresis, the subject uses yet another skin- care unit to apply massage to the skin, in order to help facilitate absorption of the skin cream into the skin.

For some applications, each of the skin-care units comprises (a) an upper part, (b) a lower part, which is shaped so as to define a lower skin-facing skin-care surface, and (c) a post, which couples the upper part to the lower part. Each of the skin-care units is configured to apply a skin-care treatment to the skin of the subject via the lower skin- facing skin-care surface.

The subject holds each of the skin-care units by holding the post between two fingers. Typically, the subject holds an upper surface of the lower part against palmar surfaces of at least two fingers, and a lower surface of the upper part against dorsal surfaces of at least the two fingers. This grasping of the skin-care unit gives the subject both a firm grip and good control of the position of the lower skin-facing skin-care surface, for application to the subject's skin. The height and the cross-sectional area or diameter of the lower part are typically such that the fingers can feel the skin (e.g., of the face) around the lower part. This provides sensory feedback for the subject while she is using, for example, the abrasion skin-care unit, which may improve the application of the abrasion, or the iontophoresis and massage skin-care units, for which she may receive realtime feedback regarding the success and/or level of completion of the iontophoretic treatment and/or massage treatment. Typically, the post of each of the skin-care units has a length, measured along a longitudinal axis of the post, of between 10 and 20 mm. Typically, the post has an average cross-sectional areas therealong, measured perpendicular to the longitudinal axis, of between 0.75 and 30 mm2, and/or for applications in which the post is circular in cross- section, a diameter of between 1 and 6 mm. These dimensions of the post generally provide for comfortable holding of the skin-care unit.

For some applications, a greatest cross- sectional area of the upper part, measured perpendicular to the longitudinal axis of the post, is between 19 and 3900 mm2. Alternatively or additionally, for applications in which the upper part is circular, the upper part has a diameter of between 5 and 40 mm. For some applications, a greatest cross- sectional area of the lower part, measured perpendicular to the longitudinal axis of the post, is between 19 and 1300 mm2. Alternatively or additionally, for applications in which the lower part is circular, the lower part has a diameter, measured perpendicular to the longitudinal axis of the post, of between 5 and 40 mm.

There is therefore provided, in accordance with some applications of the present invention, apparatus including a skin-care unit, which includes:

an upper part;

a lower part, which is shaped so as to define a lower skin-facing skin-care surface that has a surface area of between 19 and 1300 mm2; and

a post, which couples the upper part to the lower part, and which has (a) a length, measured along a longitudinal axis of the post, of between 10 and 20 mm, and (b) an average cross-sectional area therealong, measured perpendicular to the longitudinal axis, of between 0.75 and 30 mm2,

wherein the skin-care unit is configured to apply a skin-care treatment to skin of a subject via the lower skin-facing skin-care surface,

wherein a greatest cross- sectional area of the upper part, measured perpendicular to the longitudinal axis of the post, is between 19 and 3900 mm2, and

wherein a greatest cross- sectional area of the lower part, measured perpendicular to the longitudinal axis of the post, is between 19 and 1300 mm2.

For some applications, the apparatus further includes a skin cream.

For some applications, the surface area of the lower skin-facing skin-care surface is between 175 and 960 mm2. For some applications, the lower skin-facing skin-care surface is convex.

For some applications, a closest distance between any portion of the upper part and any portion of the lower part is at least 10 mm.

For some applications, the lower part is shaped so as to define a lower-part upper surface, which (a) faces away from the lower skin-facing skin-care surface, and (b) includes a generally flat portion that defines an angle of between 85 and 95 degrees with the longitudinal axis of the post.

For some applications, the upper part is shaped so as to define an upper-part lower surface, which (a) faces toward the lower part, and (b) includes a generally flat portion that defines an angle of between 85 and 95 degrees with the longitudinal axis of the post. For some applications, the greatest cross-sectional area of the upper part equals between 110% and 160% of the greatest cross-sectional area of the lower part. For some applications, a greatest height of the upper part equals between 100% and 250% of a greatest height of the lower part, both heights measured parallel to the longitudinal axis of the post.

For some applications, a greatest height of the upper part, measured parallel to the longitudinal axis of the post, is between 1 and 12 mm.

For some applications, a greatest height of the lower part, measured parallel to the longitudinal axis of the post, is between 1 and 5 mm.

For some applications, the lower part is circular in cross-section perpendicular to the longitudinal axis of the post. For some applications, the upper part is circular in cross-section perpendicular to the longitudinal axis of the post.

For some applications, a total mass of the skin-care unit is between 2 and 20 grams.

For some applications, a total water-displacement volume of the skin-care unit is between 5 and 60 cm3.

For some applications, a cross-sectional shape of the post, perpendicular to the longitudinal axis, is elliptical.

For some applications, the cross-sectional shape is circular.

For some applications, a cross-sectional shape of the post, perpendicular to the longitudinal axis, is polygonal.

For some applications, a cross-sectional shape of the post, perpendicular to the longitudinal axis, is constant along the post.

For some applications, an external surface of the post is soft.

For some applications, the upper part is shaped so as to define an upper-part lower surface, which (a) faces toward the lower part, and (b) is soft, and the lower part is shaped so as to define a lower-part upper surface, which (a) faces away from the lower skin- facing skin-care surface, and (b) is soft. For some applications, the upper part is shaped so as to define an upper-part upper surface, which (a) faces away from the lower part, and (b) is harder than the external surface of the post.

For some applications, the post is flexible. For some applications, the upper part is shaped so as to define an upper-part upper surface, which (a) faces away from the lower part, and (b) is rigid.

For some applications, the upper part is shaped so as to define (a) an upper-part upper surface, which faces away from the lower part, and (b) an upper-part lower surface, which faces toward the lower part, wherein the upper-part upper surface is harder than the upper-part lower surface.

For some applications, the upper part is shaped so as to define an upper-part upper surface, which (a) faces away from the lower part, and (b) is harder than the lower skin- facing skin-care surface.

For some applications, the skin-care unit is a first skin-care unit, wherein the upper and lower parts are first upper and lower parts, respectively, and wherein the post is a first post,

the skin-care treatment is a first skin-care treatment, and

the apparatus further includes a second skin-care unit, which includes:

a second upper part;

a second lower part, which is shaped so as to define a second lower skin-facing skin-care surface that has a surface area of between 19 and 1300 mm2; and

a second post, which couples the second upper part to the second lower part, and which has (a) a length, measured along a longitudinal axis of the second post, of between 10 and 20 mm, and (b) an average cross -sectional area therealong, measured perpendicular to the longitudinal axis, of between 0.75 and 30 mm2,

wherein the second skin-care unit is configured to apply a second skin-care treatment to the skin of the subject via the second lower skin-facing skin-care surface, which second skin-care treatment is different from the first skin-care treatment,

wherein a greatest cross-sectional area of the second upper part, measured perpendicular to the longitudinal axis of the second post, is between 19 and 3900 mm2, and wherein a greatest cross-sectional area of the second lower part, measured perpendicular to the longitudinal axis of the second post, is between 19 and 1300 mm2.

For some applications, the first and the second upper parts have respective, different cross-sectional shapes perpendicular to the longitudinal axes of the first and the second posts, respectively.

For some applications, the apparatus further includes a third skin-care unit, which includes:

a third upper part;

a third lower part, which is shaped so as to define a third lower skin-facing skin- care surface that has a surface area of between 19 and 1300 mm2; and

a third post, which couples the third upper part to the third lower part, and which has (a) a length, measured along a longitudinal axis of the third post, of between 10 and 20 mm, and (b) an average cross- sectional area therealong, measured perpendicular to the longitudinal axis, of between 0.75 and 30 mm2,

wherein the third skin-care unit is configured to apply a third skin-care treatment to the skin of the subject via the third lower skin-facing skin-care surface, which third skin-care treatment is different from the first skin-care treatment and from the second skin-care treatment,

wherein a greatest cross- sectional area of the third upper part, measured perpendicular to the longitudinal axis of the third post, is between 19 and 3900 mm2, and wherein a greatest cross- sectional area of the third lower part, measured perpendicular to the longitudinal axis of the third post, is between 19 and 1300 mm2.

For some applications, the first skin-care treatment is skin-care abrasion, wherein the first lower skin-facing skin-care surface includes a skin-abrasion surface,

wherein the second skin-care treatment is massage, and wherein the second skin- care unit is configured to apply the massage to the skin via the second lower skin-facing skin-care surface, and

wherein the third skin-care treatment is iontophoresis, and wherein the third skin- care unit includes (a) a plurality of electrodes, at least one of which is positioned on the third lower skin-facing skin-care surface, (b) a power source, and (c) a control unit, electrically coupled to the power source and the electrodes, and configured to drive the electrodes to apply the iontophoresis to the skin via the third lower skin-facing skin-care surface.

For some applications, the first, the second, and the third upper parts have respective, different cross- sectional shapes perpendicular to the longitudinal axes of the first, the second, and the third posts, respectively.

For some applications, the skin-care treatment is skin-care abrasion, and wherein the lower skin-facing skin-care surface includes a skin-abrasion surface.

For some applications, the skin-care unit includes:

a power source; and

an electrical vibrating element, electrically coupled to the power source.

For some applications, the skin-care unit is configured to provide a subject- selectable variable level of roughness to the lower skin-facing skin-abrasion surface.

For some applications, the lower part is one of a set of lower parts, which are removably couplable to the post, and which are shaped so as to define respective lower skin-facing skin-abrasion surfaces having respective, different levels of roughness.

For some applications, the lower part is shaped so as to define a lower-part upper surface, which faces away from the lower skin-facing skin-abrasion surface,

wherein the lower part includes a soft element disposed between the lower skin- facing skin-abrasion surface and the lower-part upper surface. For some applications, the skin-care treatment is application of a high frequency micro-current, wherein the skin-care unit includes:

a plurality of electrodes, at least one of which is positioned on the lower skin- facing skin-care surface;

a power source; and

a control unit, electrically coupled to the power source and the electrodes, and configured to drive the electrodes to apply the high frequency micro-current to the skin via the lower skin-facing skin-care surface.

For some applications, the control unit is configured to apply the high frequency micro-current at a frequency of 300 - 5000 Hz. For some applications, the control unit is configured to apply the high frequency micro-current at an amplitude of less than 1 milliamp. For some applications, the skin-care treatment is iontophoresis, wherein the skin- care unit includes:

a plurality of electrodes, at least one of which is positioned on the lower skin- facing skin-care surface;

a power source; and

a control unit, electrically coupled to the power source and the electrodes, and configured to drive the electrodes to apply an iontophoretic current to the skin via the lower skin-facing skin-care surface.

For some applications, the apparatus further includes a skin cream that includes ions, wherein the control unit is configured to configure the iontophoretic current to drive the skin cream into the skin.

For some applications, at least one of the electrodes is positioned on an external surface of the post.

For some applications, the control unit is configured to apply the iontophoretic current at less than 1 mA per cm2 of a skin-facing surface of the electrode.

For some applications, the control unit is configured to apply the iontophoretic current as direct current (DC).

For some applications, the control unit is configured to apply the iontophoretic direct current as a series of pulses. For some applications, the control unit is configured to apply the iontophoretic current as a series of alternating positive and negative pulses, having an average pulse duration of at least 1 ms.

For some applications, the average pulse duration is at least 2 seconds.

For some applications, the apparatus further includes a skin cream including positive and negative ions.

For some applications, the control unit is configured to apply the iontophoretic current at a frequency of up to 1 Hz.

For some applications, the control unit is configured to apply the iontophoretic current as a series of pulses at a frequency of between 1.5 kHz and 2.5 kHz. For some applications, the power source and the control unit are housed in the upper part.

For some applications, the control unit is configured to sense closing of a circuit between at least two of the electrodes upon contact with the skin, and to automatically drive the electrodes to apply the iontophoretic current upon sensing.

For some applications, the skin-care unit further includes a visual indicator of activation of the control unit.

For some applications, the skin-care unit further includes a subject-activatable switch, which is electrically coupled to the control unit, and configured to control activation of the control unit.

For some applications, the skin-care unit further includes a visual indicator of activation of the control unit.

For some applications, the skin-care treatment is massage, and wherein the skin- care unit is configured to apply the massage to the skin via the lower skin-facing skin-care surface.

For some applications, the lower skin-facing skin-care surface is shaped so as to define a plurality of skin-facing protrusions that are configured to apply the massage.

For some applications, the skin-care unit includes:

a power source; and

an electrical vibrating element, electrically coupled to the power source.

For some applications, the apparatus further includes a skin cream.

There is further provided, in accordance with some applications of the present invention, a method including:

holding, by a subject, a skin-care unit, which includes (a) an upper part, (b) a lower part, which is shaped so as to define a lower skin-facing skin-care surface that has a surface area of between 19 and 1300 mm2, and (c) a post, which couples the upper part to the lower part, and which has (i) a length, measured along a longitudinal axis of the post, of between 10 and 20 mm, and (ii) an average cross-sectional area therealong, measured perpendicular to the longitudinal axis, of between 0.75 and 30 mm2, wherein a greatest cross- sectional area of the upper part, measured perpendicular to the longitudinal axis of the post, is between 19 and 3900 mm2, and wherein a greatest cross-sectional area of the lower part, measured perpendicular to the longitudinal axis of the post, is between 19 and 1300 mm2; and

using the skin-care unit, applying a skin-care treatment to skin of the subject by bringing the lower skin-facing skin-care surface into contact with the skin,

wherein holding the skin-care unit includes holding the post between two fingers of the subject.

For some applications, the method further includes applying a skin cream to the skin at a skin site, wherein applying the skin-care treatment includes bringing the lower skin-facing skin-care surface into contact with the skin at the skin site.

For some applications, the surface area of the lower skin-facing skin-care surface is between 175 and 960 mm2.

For some applications, the lower skin-facing skin-care surface is convex, and wherein bringing the lower skin-facing skin-care surface into contact with the skin includes bringing the convex lower skin-facing skin-care surface into contact with the skin.

For some applications, a closest distance between any portion of the upper part and any portion of the lower part is at least 10 mm.

For some applications, the lower part is shaped so as to define a lower-part upper surface, which faces away from the lower skin-facing skin-care surface,

wherein holding the skin-care unit includes holding the skin-care unit with the lower-part upper surface against palmar surfaces of at least the two fingers.

For some applications, the lower-part upper surface includes a generally flat portion that defines an angle of between 85 and 95 degrees with the longitudinal axis of the post.

For some applications, the upper part is shaped so as to define an upper-part lower surface, which (a) faces toward the lower part,

wherein holding the skin-care unit includes holding the skin-care unit with the upper-part lower surface against dorsal surfaces of at least the two fingers. For some applications, the upper-part lower surface includes a generally flat portion that defines an angle of between 85 and 95 degrees with the longitudinal axis of the post.

For some applications, the greatest cross-sectional area of the upper part equals between 110% and 160% of the greatest cross-sectional area of the lower part.

For some applications, a greatest height of the upper part equals between 100% and 250% of a greatest height of the lower part, both heights measured parallel to the longitudinal axis of the post.

For some applications, a greatest height of the upper part, measured parallel to the longitudinal axis of the post, is between 1 and 12 mm.

For some applications, a greatest height of the lower part, measured parallel to the longitudinal axis of the post, is between 1 and 5 mm.

For some applications, the lower part is circular in cross-section perpendicular to the longitudinal axis of the post. For some applications, the upper part is circular in cross-section perpendicular to the longitudinal axis of the post.

For some applications, a total mass of the skin-care unit is between 2 and 20 grams.

For some applications, a total water-displacement volume of the skin-care unit is between 5 and 60 cm3.

For some applications, a cross-sectional shape of the post, perpendicular to the longitudinal axis, is elliptical.

For some applications, the cross-sectional shape is circular.

For some applications, a cross-sectional shape of the post, perpendicular to the longitudinal axis, is polygonal.

For some applications, a cross-sectional shape of the post, perpendicular to the longitudinal axis, is constant along the post. For some applications, an external surface of the post is soft, and wherein holding the post includes holding the post between the two fingers such that the fingers contact the soft external surface of the post.

For some applications, (a) the upper part is shaped so as to define an upper-part lower surface, which (i) faces toward the lower part, and (ii) is soft, and (b) the lower part is shaped so as to define a lower-part upper surface, which (i) faces away from the lower skin-facing skin-care surface, and (ii) is soft,

wherein holding the skin-care unit includes holding the skin-care unit with the lower-part upper surface against palmar surfaces of at least the two fingers, and the upper- part lower surface against dorsal surfaces of at least the two fingers.

For some applications, the upper part is shaped so as to define an upper-part upper surface, which (a) faces away from the lower part, and (b) is harder than the external surface of the post.

For some applications, the post is flexible. For some applications, the upper part is shaped so as to define an upper-part upper surface, which (a) faces away from the lower part, and (b) is rigid.

For some applications, the upper part is shaped so as to define (a) an upper-part upper surface, which faces away from the lower part, and (b) an upper-part lower surface, which faces toward the lower part,

wherein the upper-part upper surface is harder than the upper-part lower surface.

For some applications, the upper part is shaped so as to define an upper-part upper surface, which (a) faces away from the lower part, and (b) is harder than the lower skin- facing skin-care surface.

For some applications, the skin-care unit is a first skin-care unit, wherein the upper and lower parts are first upper and lower parts, respectively, and wherein the post is a first post,

wherein applying the skin-care treatment includes applying a first skin-care treatment,

wherein the two fingers are two first fingers, and wherein holding the skin-care unit includes holding the first post between the two first fingers, and

wherein the method further includes: holding, by the subject, a second skin-care unit, which includes (a) a second upper part, (b) a second lower part, which is shaped so as to define a second lower skin-facing skin-care surface that has a surface area of between 19 and 1300 mm2, and (c) a second post, which couples the second upper part to the second lower part, and which has (a) a length, measured along a longitudinal axis of the second post, of between 10 and 20 mm, and (b) an average cross-sectional area therealong, measured perpendicular to the longitudinal axis, of between 0.75 and 30 mm2, wherein a greatest cross-sectional area of the second upper part, measured perpendicular to the longitudinal axis of the second post, is between 19 and 3900 mm2, and wherein a greatest cross -sectional area of the second lower part, measured perpendicular to the longitudinal axis of the second post, is between 19 and 1300 mm2;

using the second skin-care unit, applying a second skin-care treatment to the skin by bringing the second lower skin-facing skin-care surface into contact with the skin, which second skin-care treatment is different from the first skin-care treatment,

wherein holding the second skin-care unit includes holding the post between two second fingers of the subject, which second fingers are selected from the group consisting of: (a) the first fingers, (b) two fingers other than the first fingers, and (c) one of the first fingers and a finger other than the first fingers.

For some applications, the first and the second upper parts have respective, different cross-sectional shapes perpendicular to the longitudinal axes of the first and the second posts, respectively.

For some applications, the method further includes:

holding, by the subject, a third skin-care unit, which includes (a) a third upper part, (b) a third lower part, which is shaped so as to define a third lower skin-facing skin-care surface that has a surface area of between 19 and 1300 mm2, and (c) a third post, which couples the third upper part to the third lower part, and which has (a) a length, measured along a longitudinal axis thereof, of between 10 and 20 mm, and (b) an average cross- sectional area therealong, measured perpendicular to the longitudinal axis, of between 0.75 and 30 mm2, wherein a greatest cross- sectional area of the third upper part, measured perpendicular to the longitudinal axis of the third post, is between 19 and 3900 mm2, and wherein a greatest cross-sectional area of the third lower part, measured perpendicular to the longitudinal axis of the third post, is between 19 and 1300 mm2; using the third skin-care unit, applying a third skin-care treatment to the skin by bringing the second lower skin-facing skin-care surface into contact with the skin, which third skin-care treatment is different from the first skin-care treatment and from the second skin-care treatment,

wherein holding the third skin-care unit includes holding the post between two third fingers of the subject, which third fingers are selected from the group consisting of: (a) the first fingers, (b) two fingers other than the first fingers, and (c) one of the first fingers and a finger other than the first fingers.

For some applications, the first skin-care treatment is skin-care abrasion, wherein the first lower skin-facing skin-care surface includes a skin- abrasion surface, and wherein applying the first skin-care treatment includes removing dead cells of a stratum corneum of the skin by applying abrasion to the skin by bringing the first skin-abrasion surface into contact with the skin,

wherein the second skin-care treatment is massage, wherein the second skin-care unit is configured to apply the massage to the skin via the second lower skin-facing skin- care surface, and wherein applying the second skin-care treatment includes applying the massage to the skin via the second lower skin-facing skin-care surface by bringing the second lower skin-facing skin-care surface into contact with the skin, and

wherein the third skin-care treatment is iontophoresis, wherein the third skin-care unit includes (a) a plurality of electrodes, at least one of which is positioned on the third lower skin-facing skin-care surface, (b) a power source, and (c) a control unit, electrically coupled to the power source and the electrodes, and configured to drive the electrodes to apply the iontophoresis to the skin via the third lower skin-facing skin-care surface, and wherein applying the third skin-care treatment includes applying the iontophoresis. For some applications, applying the first, the second, and the third skin-care treatments includes:

removing dead cells of a stratum corneum of the skin by applying the abrasion to the skin by bringing the first skin-abrasion surface into moving contact with the skin at a skin site;

after removing the dead cells, applying, to the skin at the skin site, a skin cream that includes ions;

after applying the skin cream, applying the iontophoresis by bringing the third lower skin-facing skin-care surface into contact with the skin at the skin site; and before or after applying the iontophoresis, applying the massage by bringing the second lower skin-facing skin-care surface into contact with the skin at the skin site.

For some applications, the first, the second, and the third upper parts have respective, different cross- sectional shapes perpendicular to the longitudinal axes of the first, the second, and the third posts, respectively.

For some applications, the skin-care treatment is skin-care abrasion, and the lower skin-facing skin-care surface includes a skin-abrasion surface,

wherein applying the skin-care treatment includes removing dead cells of a stratum corneum of the skin by applying abrasion to the skin by bringing the skin- abrasion surface into moving contact with the skin.

For some applications, the skin-care unit includes (a) a power source, and (b) an electrical vibrating element, electrically coupled to the power source,

wherein applying the abrasion includes vibrating the skin-abrasion surface using the vibrating unit. For some applications, the skin-care unit is configured to provide a subject- selectable variable level of roughness to the lower skin-facing skin-abrasion surface, wherein applying the abrasion includes selecting, by the subject, the level of roughness.

For some applications, the lower part is one of a set of lower parts, which are removably couplable to the post, and which are shaped so as to define respective lower skin-facing skin-abrasion surfaces having respective, different levels of roughness,

wherein applying the abrasion includes selecting the lower part from the set of lower parts, and coupling the lower part to the post.

For some applications, the lower part is shaped so as to define a lower-part upper surface, which faces away from the lower skin-facing skin-abrasion surface,

wherein the lower part includes a soft element disposed between the lower skin- facing skin-abrasion surface and the lower-part upper surface.

For some applications, the skin-care treatment is iontophoresis, wherein the skin- care unit includes (a) a plurality of electrodes, at least one of which is positioned on the lower skin-facing skin-care surface, (b) a power source, and (c) a control unit, electrically coupled to the power source and the electrodes, and configured to drive the electrodes to apply an iontophoretic current to the skin via the lower skin-facing skin-care surface, and wherein applying the skin-care treatment includes applying the iontophoresis.

For some applications, the method further includes applying, to the skin at a skin site, a skin cream that includes ions,

wherein the control unit is configured to configure the iontophoretic current to drive the skin cream into the skin, and

wherein applying the iontophoresis includes bringing the lower skin-facing skin- care surface into contact with the skin at the skin site. For some applications, at least one of the electrodes is positioned on an external surface of the post,

wherein holding the post includes holding the post between the two fingers such that at least one of the two fingers is in contact with the at least one of the electrodes positioned on the external surface of the post. For some applications, the control unit is configured to apply the iontophoretic current at less than 1 mA per cm2 of a skin-facing surface of the electrode.

For some applications, the control unit is configured to apply the iontophoretic current as direct current (DC).

For some applications, the control unit is configured to apply the iontophoretic direct current as a series of pulses.

For some applications, the control unit is configured to apply the iontophoretic current as a series of alternating positive and negative pulses, having an average pulse duration of at least 1 ms.

For some applications, the average pulse duration is at least 2 seconds. For some applications, the method further includes applying, to the skin at a skin site, a skin cream including positive and negative ions, wherein applying the iontophoresis includes bringing the lower skin-facing skin-care surface into contact with the skin at the skin site.

For some applications, the control unit is configured to apply the iontophoretic current at a frequency of up to 1 Hz. For some applications, the control unit is configured to apply the iontophoretic current as a series of pulses at a frequency of between 1.5 kHz and 2.5 kHz.

For some applications, the power source and the control unit are housed in the upper part. For some applications, the control unit is configured to sense closing of a circuit between at least two of the electrodes upon contact with the skin, and to automatically drive the electrodes to apply the iontophoretic current upon sensing.

For some applications, the skin-care unit further includes a visual indicator of activation of the control unit. For some applications, the skin-care unit further includes a subject-activatable switch, which is electrically coupled to the control unit, and configured to control activation of the control unit,

wherein applying the skin-care treatment includes activating the switch by the subject. For some applications, the skin-care unit further includes a visual indicator of activation of the control unit.

For some applications, the skin-care treatment is massage,

wherein applying the skin-care treatment includes applying the massage to the skin via the lower skin-facing skin-care surface by bringing the lower skin-facing skin- care surface into contact with the skin.

For some applications, the lower skin-facing skin-care surface is shaped so as to define a plurality of skin-facing protrusions that are configured to apply the massage, wherein applying the massage includes applying the massage by bringing the skin- facing protrusions into contact with the skin. For some applications, the skin-care unit includes (a) a power source, and (b) an electrical vibrating element, electrically coupled to the power source,

wherein applying the massage includes vibrating the lower skin-facing skin-care surface using the vibrating unit.

For some applications, the method further includes applying, to the skin at a skin site, a skin cream, wherein applying the massage includes bringing the lower skin-facing skin-care surface into contact with the skin at the skin site. There is further provided, in accordance with some applications of the present invention, apparatus including:

a container, which includes a magnet; and

a skin cream, contained in the container. For some applications, the apparatus further includes a skin-care unit, which (a) is shaped so as to define a lower skin-facing skin-care surface, and (b) includes:

a power source; and

a control unit, which is electrically coupled to the power source, and which is configured to apply, only when activated upon sensing the magnet, a skin-care treatment to skin of a subject via the lower skin-facing skin-care surface.

For some applications, the skin cream includes ions and the apparatus includes electrodes electrically coupled to the control unit.

There is further provided, in accordance with some applications of the present invention, apparatus including:

a container, which includes an activation element; and

a skin cream, contained in the container.

For some applications, the apparatus further includes a skin-care unit, which (a) is shaped so as to define a lower skin-facing skin-care surface, and (b) includes:

a power source;

a reader, which is configured to read information from the activation element; and a control unit, which is electrically coupled to the power source and the reader, and which is configured to apply, only upon finding that the read information specifies a particular code, a skin-care treatment to skin of a subject via the lower skin-facing skin- care surface. For some applications, the control unit is configured to function for only a limited amount of time or number of times for the code specified by the information.

For some applications, the activation element includes circuitry.

For some applications, the activation element includes a radio-frequency identification (RFID) tag. For some applications, the activation element includes a machine -readable code. There is further provided, in accordance with some applications of the present invention, apparatus including:

a container;

a skin cream, contained in the container;

an electronic chip; and

packaging, which packages the container and the electronic chip.

For some applications, the apparatus further includes a skin-care unit, which (a) is shaped so as to define a lower skin-facing skin-care surface, and (b) includes:

a power source;

a reader, which is configured to read information from the activation element; and a control unit, which is electrically coupled to the power source and the reader, and which is configured to apply, only upon finding that the read information specifies a particular code, a skin-care treatment to skin of a subject via the lower skin-facing skin- care surface. For some applications, the control unit is configured to function for only a limited amount of time or number of times for the code specified by the information.

There is further provided, in accordance with some applications of the present invention, apparatus including:

a container;

a skin cream, contained in the container; and

a skin-care unit, which (a) is shaped so as to define a lower skin-facing skin-care surface, and (b) includes:

a control unit, which is configured to apply a skin-care treatment to skin of a subject via the lower skin-facing skin-care surface; and

a power source, which is electrically coupled to the control unit, and which includes a battery having a capacity selected to be sufficient for application of the skin-care treatment using a quantity of the skin cream that is not more than three times the amount of the skin cream contained in the container.

For some applications, the capacity of the battery is no more than 60 mAh. The present invention will be more fully understood from the following detailed description of embodiments thereof, taken together with the drawings, in which: BRIEF DESCRIPTION OF THE DRAWINGS

Figs. 1A and IB are schematic illustrations of a set of skin-care units, from respective views, in accordance with an application of the present invention;

Fig. 2 is a schematic illustration of a subject holding one of the skin-care units of Figs. 1 A-B in a hand, in accordance with an application of the present invention;

Fig. 3 is a schematic illustration of a subject using one of the skin-care units of Figs. 1A-B to apply a skin-care treatment to a face of the subject, in accordance with an application of the present invention;

Fig. 4 is a schematic cross-sectional illustration of the set of skin-care units of Figs. 1A-B, in accordance with an application of the present invention;

Fig. 5 is a schematic illustration of the set of skin-care units of Figs. 1A-B, in accordance with an application of the present invention;

Fig. 6 is a schematic illustration of another skin-care unit, in accordance with an application of the present invention; and Fig. 7 is a schematic illustration of a kit comprising the set of skin-care units of

Figs. 1A-B and a container of skin cream, in accordance with an application of the present invention.

DETAILED DESCRIPTION OF APPLICATIONS

Figs. 1A and IB are schematic illustrations of a set 20 of skin-care units, from respective views, in accordance with an application of the present invention. The skin- care units are configured to apply one or more skin-care treatments to skin of a subject, such as skin of a face of the subject. For some applications, the skin-care units are configured to apply a skin cream to the skin of the subject. Optionally, the skin cream is provided in a kit in combination with the skin-care units, such as described hereinbelow with reference to Fig. 7.

Set 20 typically comprises between one and five skin-care units, e.g., three skin- care units, such as first, second, and third skin-care units 30, 40, and 50, as illustrated. The skin-care units may be used sequentially to treat the skin, such as described hereinbelow. For some applications, first, second, and third skin-care units 30, 40, and 50 comprise:

• respective first, second, and third upper parts 70A, 70B, and 70C;

• respective first, second, and third lower parts 72A, 72B, and 72C, which are shaped so as to define respective first, second, and third lower skin-facing skin- care surfaces 100A, 100B, and lOOC; and

• respective first, second, and third posts 74A, 74B, and 74C, which couple respective first, second, and third upper parts 70 A, 70B, and 70C to respective first, second, and third lower parts 72A, 72B, and 72C.

The skin-care units are configured to apply respective skin-care treatments to the skin of the subject via the respective lower skin-facing skin-care surfaces.

For some applications, lower parts 72A, 72B, and 72C are circular in cross-section perpendicular to respective longitudinal axes 90A, 90B, and 90C of respective posts 74A, 74B, 74C (the axes are labeled in Fig. 4, described hereinbelow). For some applications, upper parts 70A, 70B, and 70C are circular in cross-section perpendicular to respective longitudinal axes 90A, 90B, and 90C of respective posts 74A, 74B, and 74C. Alternatively, at least two (e.g., all) of upper parts 70A, 70B, and 70C have respective, different cross-sectional shapes perpendicular to longitudinal axes 90A, 90B, and 90C, such as described hereinbelow with reference to Fig. 5.

For some applications, a cross- sectional shape of one or more the posts, perpendicular to the respective longitudinal axes, is elliptical, such as circular. Alternatively, for some applications, a cross-sectional shape of one or more the posts, perpendicular to the respective longitudinal axes, is polygonal. Alternatively or additionally, for some applications, a cross- sectional shape of one or more of the posts, perpendicular to the respective longitudinal axes, is constant along the posts. Typically, each of lower skin-facing skin-care surfaces 100A, 100B, and lOOC has a surface area of at least 19 mm2 (e.g., at least 175 mm2, or at least 300 mm2), no more than 1300 mm2 (e.g., no more than 960 mm2), and/or between 19 and 1300 mm2, such as at least 175 mm2, no more than 960 mm2, and/or between 175 and 960 mm2, and/or, for applications in which the lower skin-facing skin-care surfaces are circular, a diameter of at least 5 mm (e.g., at least 15 mm or at least 20 mm), no more than 40 mm (e.g., no more than 35 mm), and/or between 5 and 40 mm, such as at least 15 mm, no more than 35 mm, and/or between 15 and 35 mm. For some applications, one or more of lower skin-facing skin-care surfaces 100 A, 100B, and lOOC are convex, as shown in the figures. Alternatively or additionally, one or more of the lower skin-facing skin-care surfaces are flat (configuration not shown). For some applications, a closest distance between any portion of first upper part

70A and any portion of first lower part 72A is at least 10 mm. First upper part 70A and first lower part 72A typically do not touch each other. For some applications, a closest distance between any portion of second upper part 70B and any portion of second lower part 72B is at least 10 mm. Second upper part 70B and second lower part 72B typically do not touch each other. For some applications, a closest distance between any portion of third upper part 70C and any portion of third lower part 72C is at least 10 mm. Third upper part 70C and third lower part 72C typically do not touch each other.

For some applications, first, second, and third lower parts 72A, 72B, and 72C are shaped so as to define respective first, second, and third lower-part upper surfaces 102A, 102B, and 102C, which (a) face away from respective first, second, and third lower skin- facing skin-care surface 100A, 100B, and lOOC, and (b) includes respective generally flat portions, each of which defines an angle of between 85 and 95 degrees, such as 90 degrees, with respective longitudinal axes 90A, 90B, and 90C of respective posts 74A, 74B, 74C. Alternatively, the flat portions form other non-perpendicular angles with the axes.

For some applications, first, second, and third upper parts 70A, 70B, and 70C are shaped so as to define respective first, second, and third upper-part lower surfaces 104 A, 104B, and 104C, which (a) face toward respective first, second, and third lower parts 72A, 72B, and 72C, and (b) include respective generally flat portions, each of which defines an angle of between 85 and 95 degrees, such as 90 degrees with respective longitudinal axes 90A, 90B, and 90C of respective posts 74A, 74B, 74C. Alternatively, the flat portions form other non-perpendicular angles with the axes.

For some applications, a total mass of each of first, second, and third skin-care units 30, 40, and 50 is at least 2 grams, no more than 20 grams, and/or between 2 and 20 grams. For some applications, a total water-displacement volume of each of the skin-care units is at least 5 cm3, no more than 60 cm3, and/or between 5 and 60 cm3.

For some applications, one or more of first, second, and third posts 74A, 74B, and 74C are flexible.

Reference is now made to Fig. 2, which is a schematic illustration of a subject holding one of the skin-care units in a hand 62, in accordance with an application of the present invention. Although the hand is illustrated holding third skin-care unit 50, the same grasping technique is typically used for the other skin-care units of set 20, including first and second skin-care units 30 and 40.

As can be seen in the figure, the subject holds skin-care unit 50 by holding post 74C between two of fingers 60 of the subject. Typically, the subject holds:

• lower-part upper surface 102C against palmar surfaces 64 of at least two of fingers 60, typically the same two fingers between which the post is held, and

• upper-part lower surface 104C against dorsal surfaces 66 of at least the two of fingers 60, typically the same two fingers between which the post is held.

This grasping of the skin-care unit gives the subject both a firm grip and good control of the position of the lower skin-facing skin-care surface, for application to the subject's skin. The height and the cross- sectional area or diameter of the lower part are typically such that the fingers can feel the skin (e.g., of the face) around the lower part. This provides sensory feedback for the subject while she is using, for example, abrasion skin-care unit 30, which may improve the application of the abrasion, or iontophoresis and massage skin-care units 50 and 40, for which she may receive realtime feedback regarding the success and/or level of completion of the iontophoretic treatment and/or massage treatment.

The subject applies a skin-care treatment to the subject's skin by bringing the lower skin-facing skin-care surface into contact with the skin. The subject may hold all three devices (at different times) between the same two fingers, or hold one or two of the devices between different sets of fingers.

For some applications, one or more (such as all) of the following finger-contacting surfaces are soft:

• an external surface of the post;

• the upper-part lower surface; and/or · the lower-part upper surface is soft. The softness of these finger-contacting surfaces may provide for comfortable usage of the skin-care unit.

Reference is now made to Fig. 3, which is a schematic illustration of a subject using one of the skin-care units to apply a skin-care treatment to a face 68 of the subject, in accordance with an application of the present invention. Although the subject is illustrated using second skin-care unit 40, the same application technique is typically used for the other skin-care units of set 20, including first and third skin-care units 30 and 50.

As can be seen in the figure, the subject holds the skin-care unit as shown in Fig. 2, and applies a skin-care treatment to the skin of face 68 of the subject by bringing the lower skin-facing skin-care surface into contact with the skin. As mentioned above, the height and the cross- sectional area or diameter of the lower part are typically such that the fingers can feel the skin (e.g., of the face) around the lower part.

Reference is now made to Fig. 4, which is a schematic cross- sectional illustration of set 20 of skin-care units 30, 40, and 50, in accordance with an application of the present invention.

Typically, first, second, and third posts 74A, 74B, and 74C have respective lengths LI, L2, and L3, measured along respective longitudinal axes 90A, 90B, and 90C of the posts, each of which lengths is at least 10 mm, no more than 20 mm, and/or between 10 and 20 mm. Typically, first, second, and third posts 74A, 74B, and 74C have (a) respective average cross- sectional areas therealong, measured perpendicular to respective longitudinal axes 90A, 90B, and 90C, of at least 0.75 mm2 (e.g., at least 3 mm2), no more than 80 mm2 (e.g., no more than 30 mm2), and/or between 0.75 and 80 mm2, such as between 0.75 and 30 mm2, e.g., between 3 and 30 mm2, and/or (b) for applications in which the posts are circular in cross-section, respective diameters of at least 1 mm (e.g., at least 2 mm), no more than 10 mm (e.g., no more than 6 mm), and/or between 1 and 10 mm, such as between 1 and 6 mm, e.g., between 2 and 6 mm. These dimensions of the posts generally provide for comfortable holding of the skin-care units, as described hereinabove with reference to Fig. 2.

For some applications, a greatest cross- sectional area of each of upper parts 70A, 70B, and 70C, measured perpendicular to the respective longitudinal axes of the posts, is at least 19 mm2 (e.g., at least 78 mm2), no more than 3900 mm2 (e.g., no more than 1250 mm2), and/or between 19 and 3900 mm2, such as between 78 and 1250 mm2. Alternatively or additionally, for applications in which the upper parts are circular, each of respective diameters D4, D5, and D6 of the upper parts, measured perpendicular to the respective longitudinal axes of the posts, is at least 5 mm (e.g., at least 10 mm), no more than 70 mm (e.g., no more than 40 mm), and/or between 5 mm and 70 mm, such as between 10 and 40 mm.

For some applications, a greatest cross- sectional area of each lower parts 72A, 72B, and 72C, measured perpendicular to respective longitudinal axes 90A, 90B, and 90C of the respective posts, is at least 19 mm2 (e.g., at least 78 mm2), no more than 1300 mm2 (e.g., no more than 700 mm2), and/or between 19 and 1300 mm2, such as between 78 and 700 mm2. Alternatively or additionally, for applications in which the lower parts are circular, each of respective greatest diameters Dl, D2, and D3 of the lower parts, measured perpendicular to the respective longitudinal axes of the posts, is at least 5 mm (e.g., at least 10 mm), no more than 40 mm (e.g. no more than 30 mm), and/or between 5 and 40 mm, such as between 10 and 30 mm. For some applications, the greatest cross- sectional area of first upper part 70A equals between 110% and 160% of the greatest cross- sectional area of first lower part 72A. For some applications, the greatest cross- sectional area of second upper part 70B equals between 110% and 160% of the greatest cross-sectional area of second lower part 72B. For some applications, the greatest cross -sectional area of third upper part 70C equals between 110% and 160% of the greatest cross- sectional area of third lower part 72C.

For some applications, each of respective greatest heights HI, H2, and H3 of upper parts 70A, 70B, and 70C, measured parallel to respective longitudinal axes 90A, 90B, and 90C of the respective posts, is at least 1 mm (e.g., at least 3 mm), no more than 12 mm (e.g., no more than 10 mm), and/or between 1 and 12 mm, such as between 3 and 10 mm. Alternatively or additionally, for some applications, each of respective greatest heights H4, H5, and H6 of lower parts 72A, 72B, and 72C, measured parallel to respective longitudinal axes 90A, 90B, and 90C of the respective posts, is at least 1 mm, no more than 5 mm, and/or between 1 and 5 mm. These ranges of cross-sectional areas or diameters of the lower parts, and heights of the lower parts, may allow the fingers to feel the skin (e.g., of the face) around the lower parts, as shown in Figs. 2 and 3. For some applications, greatest height HI equals between 100% and 250% of greatest height H4, greatest height H2 equals between 100% and 250% of greatest height H5, and/or greatest height H3 equals between 100% and 250% of greatest height H6.

For some applications, first, second, and third upper parts 70A, 70B, and 70C are shaped so as to define respective first, second, and third upper-part upper surfaces 106A, 106B, and 106C, which face away from respective lower parts 72A, 72B, and 72C. For some applications, one or more of upper-part upper surfaces 106A, 106B, and 106C are harder than respective external surfaces of first, second, and third posts 74A, 74B, and 74C. Alternatively or additionally, for some applications, one or more of upper-part upper surfaces 106A, 106B, and 106C are rigid. Further alternatively or additionally, for some applications, one or more of upper-part upper surfaces 106A, 106B, and 106C are harder than upper-part lower surfaces 104A, 104B, and 104C, respectively. Still further alternatively or additionally, for some applications, one or more of upper-part upper surfaces 106 A, 106B, and 106C are harder than lower skin-facing skin-care surfaces 100A, 100B, and lOOC, respectively.

For some applications, one or more of the posts are shaped as flat thin boards, e.g., beams. For example, each of the boards may extend partially or entirely across the diameter of the lower part.

Reference is now made to Figs. 1A-B and 4. Typically, first, second, and third skin-care units 30, 40, and 50 are configured to apply different, respective skin-care treatments.

The first skin-care unit

For some applications, first skin-care unit 30 is configured to apply a first skin- care treatment, which is skin-care abrasion, and first lower skin-facing skin-care surface 100A comprises a skin-abrasion surface 84. For example, skin-abrasion surface 84 may comprise plastic. Applying abrasion to the skin, by bringing the skin-abrasion surface into moving contact with the skin, removes dead cells of a stratum corneum of the skin, which prepares the skin for application and better absorption of a skin cream, as described below. For some applications, first skin-care unit 30 comprises a power source 88A

(which may comprise a battery), an electrical vibrating element 89A, electrically coupled to the power source, and, optionally, a control unit 86A, which is configured to drive the vibrating element to vibrate. The vibrating element assists with application of the abrasion by vibrating first lower skin-facing skin-abrasion surface 84. For some applications, power source 88A and control unit 86A, and, optionally, vibrating element 89A, are housed in first upper part 70A.

For some applications, first skin-care unit 30 is configured to provide a subject- selectable variable level of roughness to first lower skin-facing skin-abrasion surface 84. The subject selects the level of roughness. For example, the skin-care unit may comprise a subject-rotatable element that adjusts the level of roughness. For some applications, first lower part 72A is one of a set of first lower parts 72A, which are removably couplable to first post 74A, and which are shaped so as to define respective first lower skin-facing skin-abrasion surfaces 84 having respective, different levels of roughness. The subject selects the lower part from the set of lower parts, and couples the lower part to the post. For some applications, first lower part 72A comprises a soft element disposed between lower skin-facing skin-abrasion surface 84 and first lower-part upper surface 102A. The soft element may cushion the skin against over-application of abrasion. For some applications, the soft elements comprise a volume filled with a soft material, e.g., a gel. The second skin-care unit

For some applications, second skin-care unit 40 is configured to apply a second skin-care treatment, which is massage, and second skin-care unit 40 is configured to apply the massage to the skin via second lower skin-facing skin-care surface 100B. The massage typically helps facilitate absorption of the skin cream into the skin, such as by increasing blood circulation beneath the skin. The massage may be applied before and/or after applying the iontophoresis, as described hereinbelow.

For some applications, second lower skin-facing skin-care surface 100B is shaped so as to define a plurality of skin-facing protrusions 82, e.g., between two and five, such as three, or exactly one, or more than five, which are configured to apply the massage. For example, protrusions 82 may be hemispherical. For some applications, protrusions 82 are soft, e.g., comprise silicone, while for other applications they are hard. For some applications, a plurality (e.g., two) of second skin-care units 40 is provided, having skin-facing protrusions 82 with different respective hardnesses. For example, one skin-care unit may have protrusions that are soft (e.g., comprise silicone) for treating the eye area, while another skin-care unit may have protrusions that are hard for treating other areas of the face. Alternatively, for some applications, lower part 72B is one of a set of lower parts 72B, which are removably couplable to post 74B, and which are shaped so as to define respective skin-facing protrusions 82 with different respective hardnesses, e.g., as described immediately above.

For some applications, second skin-care unit 40 comprises a power source 88B (which may comprise a battery), an electrical vibrating element 89B, electrically coupled to the power source, and, optionally, a control unit 86B, which is configured to drive the vibrating element to vibrate. The vibrating element assists with application of the massage by vibrating second lower skin-facing skin-care surface 100B. Vibration may help open pores in the skin. For some applications, power source 88B and control unit 86B, and, optionally, vibrating element 89B, are housed in second upper part 70B.

The third skin-care unit

For some applications, third skin-care unit 50 is configured to apply a third skin- care treatment, which is iontophoresis, and third skin-care unit 50 comprises (a) a plurality of electrodes, (b) a power source 88C (which may comprise a battery), and (c) a control unit 86C, electrically coupled to the power source and the electrodes. At least a first one of the electrodes 78 is positioned on third lower skin-facing skin-care surface lOOC. Control unit 86C is configured to drive the electrodes to apply the iontophoresis to the skin via third lower skin-facing skin-care surface lOOC. For some applications, the electrodes are disposed as described hereinbelow with reference to Fig. 6. For some applications, a skin cream is provided that comprises ions, and control unit 86C is configured to configure the iontophoretic current to drive the skin cream into the skin of the subject.

For some applications, at least a second one of the electrodes 76 is positioned on an external surface of third post 74C, such as partially or completely surrounding the post. Control unit 86C configures second electrode 76 to acts as a return electrode, via the fingers, arm, chest, and face of the subject, for the current applied through first electrode

78. The subject holds third post 74C between the two fingers 66, such as shown in Figs. 2 and 3, such that at least one of the two fingers is in contact with electrode 76 positioned on the external surface of the post.

For some applications, control unit 86C is configured to apply the iontophoretic current at less than 1 niA per cm2 of a skin-facing surface of the electrode, such as less than 0.5 niA per cm2.

For some applications, control unit 86C is configured to apply the iontophoretic current as direct current (DC).

For some applications, control unit 86C is configured to apply the iontophoretic direct current as a series of pulses. For some applications, control unit 86C is configured to apply the iontophoretic current as a series of alternating positive and negative pulses, having an average pulse duration of at least 1 ms, such as at last 2 seconds. For some applications, a skin cream is provided that comprises positive and negative ions, and control unit 86C is configured to configure the iontophoretic current to alternatively drive the positive and the negative ions into the skin of the subject, such as to drive the positive ions for at least 2 seconds, to drive the negative ions for at least 2 seconds, and to repeat this alternation.

For some applications, control unit 86C is configured to apply the iontophoretic current as a series of unidirectional or bidirectional pulses at a frequency of between 0.1 kHz and 10 kHz, e.g., between 0.1 kHz and 5 kHz, e.g., between 1.5 kHz and 2.5 kHz, such as between 1.9 kHz and 2.1 kHz, e.g., 2 kHz. Normally, skin resistance is greater than 10 kOhm, e.g., 20-100 kOhm. When a current is applied at a high frequency of about 1.5 kHz to about 10 kHz (e.g., about 2 kHz), impedance goes down to about 1 kOhm, due to capacitance of the skin (even when the skin is dry). Applying the current at this frequency allows the use of lower voltage, which may result in less skin irritation. In addition, applying the current at 2 kHz may cause a pleasant tingling feeling, which relates to pore opening that further enhances delivery of the skin cream into the skin. Typically, but not necessarily, control unit 86C applies this iontophoretic current using a relatively high duty cycle of 30-90%.

Alternatively, for some applications, control unit 86C is configured to apply the iontophoretic current at a frequency of up to 1 Hz.

For some applications, control unit 86C is configured to apply a high frequency micro-current, e.g., in order to enhance production of ATP and, for example, to enhance collagen production. For some applications, the high frequency is at least 300 Hz and/or less than 5 kHz. Alternatively or additionally, the micro-current has an amplitude of less than 1 milliamp, e.g., at least 100 microamps and/or less than 800 microamps. Application of the high frequency micro-current may be practiced even in the absence of any use of iontophoresis, or, for some applications, in combination with the use of iontophoresis described herein (simultaneously or non-simultaneously therewith).

For some applications, power source 88C and control unit 86C are housed in third upper part 70C.

For some applications, control unit 86C is configured to sense closing of a circuit between at least two of the electrodes upon contact with the skin, and to automatically drive the electrodes to apply the iontophoretic current upon sensing. Alternatively, skin- care unit 50 further comprises a subject-activatable switch, which is electrically coupled to control unit 86C, and configured to control activation of the control unit. The subject activates the switch to apply the skin-care treatment. For some applications, third skin-care unit 50 further comprises a visual indicator, such as an LED, of activation of control unit 86C. For example, the visual indicator may be disposed on upper-part upper surface 106C, such that the subject can see the indicator in a mirror when the skin-care unit is applied to the face, as shown in Fig. 3.

In an application of the present invention, a single skin-care unit is configured to perform more than one skin-care treatment, e.g., more than one of abrasion treatment, iontophoresis treatment, and massage treatment, such as all three of these treatments, or two of these treatments.

Exemplary skin-care regimen

For some applications, applying the first, the second, and the third skin-care treatments comprises:

• removing dead cells of a stratum corneum of the skin by applying the abrasion to the skin by bringing first skin-abrasion surface 84 into contact with the skin at a skin site;

• after removing the dead cells, applying, to the skin at the skin site, a skin cream that comprises ions; • after applying the skin cream, applying the iontophoresis by bringing second lower skin-facing skin-care surface lOOC into contact with the skin at the skin site; and

• before or after applying the iontophoresis, applying the massage by bringing third lower skin-facing skin-care surface 100B into contact with the skin at the skin site.

Reference is now made to Fig. 5, which is a schematic illustration of set 20 of skin-care units, in accordance with an application of the present invention. In this configuration, first, second, the third upper parts 70A, 70B, and 70C have respective, different cross-sectional shapes perpendicular to respective longitudinal axes 90A, 90B, and 90C of posts 74A, 74B, and 74C. For example, as shown, one of the upper parts may be generally square, another generally circular, and the third generally triangular. Other shapes and combinations of shapes will be evident to those skilled in the art who have read the present application, and are within the scope of the present invention. The different shapes may allow the subject to readily identify the different skin-care units.

Reference is made to Fig. 6, which is a schematic illustration of a skin-care unit 150, in accordance with an application of the present invention. Skin-care unit 150 is identical to third skin-care unit 50, described hereinabove, except that the electrodes comprise first and second electrodes 176 and 178, both of which are positioned on third lower skin-facing skin-care surface lOOC, and except typically none of the electrodes is disposed on the external surface of third post 74C. Typically, one of electrodes 176 and 178 functions as a return electrode. The features of skin-care unit 150 may be implemented in combination with any of the features of skin-care units 30, 40, and 50 described hereinabove. Reference is now made to Fig. 7, which is a schematic illustration of a kit 200 comprising set 20 of skin-care units and at least one container 210 of skin cream 212, in accordance with an application of the present invention. As described hereinabove, skin cream 212 comprises ions, selected from the group consisting of: positive ions, negative ions, and both positive and negative ions. Skin cream 212 may comprise any skin cream currently available or available in the future, such as an anti-aging cream, an antioxidant cream, an anti-wrinkle cream, a serum-infused cream, a cellular regeneration cream, a moisturizing cream, a mixture of these creams, or a cream that combines more than one of these functions, with the addition of the above-mentioned ions.

For some applications, container 210 comprises an activation element 214, e.g., disposed on a cap 216 of the container or elsewhere on the container. Activation element 214 typically comprises circuitry (e.g., comprising a radio-frequency identification (RFID) tag) and/or a machine-readable code, such as a barcode. One or more of the skin- care units comprise respective readers, which are configured to read, e.g., wirelessly, information from activation element 214. The control units of these skin-care units are typically configured to be activated only upon reading information from the activation element that specifies a particular code, such as a code that corresponds with a preconfigured code in the skin-care units.

Alternatively, for some applications, container 210 is packaged in packaging with an electronic chip 228, which must be plugged into a reader of one or more of the skin- care units in order to activate the control units. Alternatively, the electronic chip comprises a wireless communication element, and the electronic chip must be brought near the readers of the skin-care units in order to activate the control units thereof.

Further alternatively, for some applications, container 210 comprises a magnet 230, for example, which is disposed within the container (e.g., fixed to an inner wall of the container), embedded in the wall of the container, or fixed to an external surface or label of the container, such as on the main body of the container or on cap 216. The control units of the skin-care units are configured to be activated only upon sensing the magnet when the skin-care units are brought near or into contact with the magnet.

In any case, the control units of the skin-care units are typically configured to function for only a limited amount of time or number of times, based on a given code or chip that is provided with container 210. For some applications, the control units of one or more of the skin-care units are configured to be activated by activation element 214 or electronic chip 228 for only a certain number of uses, such as 10-100 (e.g., 50) uses. After this maximum number of uses, a new activation element 214 or electronic chip 228 from a new cream container 210 must be provided. For applications in which the electronic chip is provided, the control units may disable the electronic chip after the certain number of uses.

For some applications, power source 88C comprises a battery 220C having a capacity selected to be sufficient for application of the skin-care treatment using a quantity of skin cream 212 that is not more than three times the amount of skin cream in kit 200, e.g., not more than two times the amount of skin cream in kit 200. Beyond this, the battery is insufficient to facilitate application of additional skin cream. For example:

(a) the battery may have a capacity of at least 10 mAh (e.g., at least 20 mAh), no more than 80 mAh (e.g., no more than 60 mAh), and/or between 10 and

80 mAh, such as between 20 and 60 mAh,

(b) container 210 may have a volume of at least 2 ml, no more than 25 ml, and/or between 2 and 25 ml of skin cream 212, and/or

(c) the battery capacity may be at least 1 mAh/ml, no more than 4 mAh/ml, and/or between 1 and 4 mAh/ml of skin cream 212.

Typically, the battery is not rechargeable. Typically, the housing of the skin-care unit is configured to not allow replacement of the battery without causing damage to the housing. For some applications in which skin-care units 30 and 40 comprise respective power sources 88A and 88B, as described hereinabove, power sources 88A and 88B comprise respective batteries 220A and 220B, which are configured as described above regarding battery 220C.

For some applications, a logo 220 is provided on one or more of upper-part upper surfaces 106A, 106B, and 106C, and a matching logo 222 is provided on container 210, such as on cap 216 and/or elsewhere on the container. It will be appreciated by persons skilled in the art that the present invention is not limited to what has been particularly shown and described hereinabove. Rather, the scope of the present invention includes both combinations and subcombinations of the various features described hereinabove, as well as variations and modifications thereof that are not in the prior art, which would occur to persons skilled in the art upon reading the foregoing description.