Device for stimulating hair growth with multiplexer

Abstract

The invention relates to a device (100) for stimulating hair growth, comprising a plurality of electrodes (106) for electrically stimulating the skin, wherein a control device (200) connected to the plurality of electrodes (106) triggers electrical impulses via the electrodes (106). According to the invention, the control device (200) alternately pairs two electrodes (106) of the plurality of electrodes (106) as cathode and anode and applies electrical stimulation impulses, wherein the device is constructed in three parts, wherein a first part is designed as a shell (101) covering the front of the head, a second part is designed as a shell (102) covering the back of the head, and a third part (103) connects the shell (101) covering the front of the head and the shell (102) covering the back of the head in a hinged manner.

Description

[0001] The invention relates to a device for stimulating hair growth, comprising a plurality of electrodes for electrically stimulating the skin, wherein a control device connected to a plurality of the electrodes triggers electrical impulses.

[0002] It is known that electrical stimulation of the scalp can stimulate hair follicles to produce new hair growth in cases of hair loss. To stimulate the scalp, electrodes are placed on the scalp. An electric current flows through these electrodes and into the scalp. To electrically stimulate larger areas of the scalp, it is necessary to apply a roughly equal current to each area. However, this uniformity is impossible due to geometric limitations, as an electric current always flows along a path. To achieve a uniform flow of electric current across large areas of the scalp, large electrodes would be required, delivering a high current that spreads evenly.Given the skin resistance of normal, dry human skin, which is a few kiloohms, comparatively high voltages would be required to conduct a broad electrical current across the affected scalp areas. However, applying high voltages to the scalp can be life-threatening. Therefore, to achieve uniform stimulation of all scalp areas, a large number of electrodes placed close together on the scalp are necessary. These electrodes apply an electrical voltage to the skin in pairs. The numerous electrodes must have uniform electrical parameters. Specifically, the resistance of all electrode pairs must be the same to achieve consistent electrical stimulation.If electrical stimulation is regulated according to the electrical resistance of human skin, then appropriate measures must be taken to prevent excessively high voltage peaks from building up in dry areas of the affected skin.

[0003] German patent DE 10 2015 002565 A1 discloses a system for controlling stimulation impulses, comprising a pulse unit, a data processing unit, and at least one sensor. The known device is used to apply electrical stimulation impulses to a user, with the stimulation parameters being automatically adjusted based on measured physiological values. The focus is on optimized training and therapy applications through sensor-based feedback, for example, for muscle strengthening or rehabilitation. The patent describes various sensor types, such as EMG sensors, pressure sensors, or heart rate sensors, and specifically envisions applications in sports, medicine, and recreational contexts.

[0004] However, DE 10 2015 002565 A1 does not disclose a device specifically designed to stimulate hair growth. In particular, it lacks a structure in which a plurality of electrodes are arranged for the targeted electrical stimulation of the scalp, with each pair of electrodes alternately serving as cathode and anode and subjected to stimulation pulses. The design of the device in three defined parts—namely, a shell covering the front of the head, a shell covering the back of the head, and a connecting hinged part—is also not disclosed in the aforementioned patent. Adapting the geometric shape of the device to the head shape for targeted and uniform stimulation of the scalp, as well as a mechanical structure for the articulated connection of the front and back shells, is not addressed therein.

[0005] The object of the invention is therefore to provide a device for electrical stimulation of hair growth which enables uniform stimulation over larger areas of the human scalp.

[0006] The problem according to the invention is solved by the control device alternately pairing two electrodes of the plurality of electrodes as cathode and anode and applying electrical stimulation impulses, wherein the device is constructed in three parts, wherein a first part is designed as a shell covering the front of the head, a second part is designed as a shell covering the back of the head, and a third part articulately connects the shell covering the front of the head and the shell covering the back of the head. Further advantageous embodiments are specified in the dependent claims to claim 1.

[0007] According to the invention, only one or a few pairs of paired electrodes are subjected to electrical voltage at any given time. The electrodes being paired can be switched according to a fixed program or randomly. For this purpose, a control device for activating the electrodes can include a multiplexer that switches a first electrode as the anode from a first plurality of electrodes and a second electrode as the cathode from a second plurality of electrodes. The first and second plurality of electrodes can overlap. Thus, upon request from a control device, the multiplexer programmatically or randomly activates two electrodes at a time, subjecting them to an electrical voltage. Depending on the electrical resistance of the scalp, a corresponding electrical current flows between these two electrodes for stimulation.The current flowing from one electrode to the other of an electrode pair can be regulated. This can be achieved by keeping the current constant through varying the voltage, by keeping the voltage constant, or by measuring or maintaining a charge using a capacitor, so that a predetermined charge flows into the scalp. If a voltage of 5 V were applied between two electrodes, resulting in a current of 5 mA with an assumed scalp resistance of 1 kΩ, a charge of 1 mC would be discharged into the scalp after only 0.2 seconds. In this case, the time integral of the measured current intensity and the duration of the current would be regulated to achieve a defined charge as stimulation. Thus, for a given stimulation frequency f, the pulse duration can be significantly shorter than 1 / f and can be a maximum of 1 / f.

[0008] As described earlier, the control device can sequentially pair different electrodes from a pool of electrodes. The entire device can activate either only one pair of electrodes at a time, or it can activate a few pairs of electrodes that are adjacent or spaced apart on the scalp. "Spaced apart" means that the line connecting one pair of electrodes does not intersect with the line connecting another pair of electrodes that are active simultaneously on the scalp. By selectively activating electrodes, the scalp can be electrically stimulated evenly and to a sufficiently high degree.The temporal stimulation pattern, consisting of sequentially activated connecting lines, creates a network of stimulation pathways along which the electrical current flows, stimulating the scalp, which in turn produces more hair. Depending on the chosen setting, it is also possible to deliberately stimulate the scalp unevenly, thus providing stronger stimulation to areas more affected by hair loss. Depending on the type of hair loss—whether it occurs uniformly due to thinning hair or in specific areas such as baldness at the crown or temples—it is advantageous to be able to adapt the stimulation pattern to the actual distribution of hair loss.

[0009] For stimulation, an electrical stimulation pattern has proven advantageous, characterized in that, controlled by the control device, the anode of a pair of electrodes delivers an anodic stimulation pulse to the skin for a first period, which is met by the other electrode with a potential of 0V, and the cathode of a pair of electrodes delivers a cathodic stimulation pulse to the skin for a second period following the first, which is also met by the other electrode with a potential of 0V. A short rest period of approximately 1 / (10 f) to 1 / (3 f), where f = frequency, can occur between the two stimulation pulses, during which both electrodes have no potential (high resistance) or a potential of 0V.The short rest period between anodic stimulation with a positive voltage pulse against 0V and cathodic stimulation with a negative voltage pulse against 0V causes the cells to be stimulated to calm down, which presumably helps to wait for intracellular or intercellular diffusion or transport processes.

[0010] Initial experiments show that electrical stimulation with the following pulse lengths has proven particularly effective: a duration between 1 / 100 s and 10 s, with a stimulation pulse frequency between 1 / 5 Hz and 80 Hz. Within the scope of the invention, it is also hypothesized that the stimulation frequency supports intracellular or intercellular diffusion or transport processes and is therefore particularly effective within this interval.

[0011] The device for stimulating hair growth has a three-part design. Specifically, it consists of a first part designed as a shell covering the front of the head, a second part covering the back of the head, and a third part that connects the two shells via a hinge. This design allows for the coverage of bald patches at the back of the head, the forehead, and receding hairlines. Since the stimulation is primarily used for the early stages of hair loss, this design is perfectly adequate, as human hair loss typically and predominantly occurs at the back of the head, on the forehead, and on both sides of the scalp. It is also possible to address hereditary hair loss with this device.

[0012] When using the device to stimulate hair growth, it has been found that achieving uniform pressure of all electrodes on the scalp is difficult. As a result, some electrodes do not make contact, and others puncture the scalp, which is uncomfortable and therefore reduces compliance. Compliance refers to the user's motivation to participate in the treatment, whether medical or cosmetic. Therefore, it may be possible to arrange the electrodes in bundles, so that within a single tray, several electrodes are bundled together as a single, interacting electrode, with each individual electrode held in a flexible receptacle, such as a rubber grommet.The electrode bundle with elastically or flexibly arranged electrodes that rest on the scalp and do not penetrate it has the advantage that, even if the shells covering parts of the head do not fit optimally, at least one electrode rests on the scalp in the desired manner.

[0013] If the device for stimulating hair growth consists of several electrodes, each covering a portion of the scalp, the control unit can be configured to pair two electrodes from different electrodes. This pairing creates longer stretches of scalp along which an electric current flows. Stimulation can be achieved with a higher voltage. In this case, the current flows between the area of ​​baldness at the back of the head and the area of ​​baldness at the front or the sides of the scalp, where receding hairlines are located. For stimulation with a lower voltage, the control unit can be configured to pair two electrodes from identical electrodes, so that the electrical stimulation only occurs within a commonly occurring balding area.Different stimulation methods are useful when hair loss is only occurring in one area. In this case, electrodes from the same tray are paired. For larger areas with incipient hair loss, electrodes from different trays can be paired together.

[0014] In a particular embodiment of the device for stimulating hair growth, the control unit pairs two electrodes together for a single pulse sequence consisting of an anodic and a cathodic stimulation pulse, and then pairs two other electrodes together. This stimulates parts of the scalp, allowing them time to recover between stimulation pulses.

[0015] The invention is explained in more detail with reference to the following figures. They show: Fig. 1. A device according to the invention for stimulating hair growth, which rests on a human head, in a side view. Fig. 2 a view into the inner shells of the device for stimulating hair growth Fig. 1, Fig. 3a a detail on Fig. 2 in a first design, Fig. 3b a detail on Fig. 2 in a second embodiment, Fig. 4. A flowchart of the control device used, Fig. 5 mating patterns of electrodes in the device for stimulating hair growth, Fig. 6. A pulse diagram for a stimulation pulse, Fig. 7 a diagram illustrating different stimulation frequencies.

[0016] In Fig. Figure 1 shows a side view of a device 100 according to the invention for stimulating hair growth, which rests on a human head. The human head is shown here with dashed lines and is only intended to show how the device 100 is used. The device 100 consists of three parts. A front shell 101 covers the forehead of the human head and the areas where receding hairlines form in cases of hair loss. A second shell 102 is located at the back of the head and covers the area where baldness preferably develops. Both shells, shell 101 and shell 102, are connected to each other by a third part 103 in a pivotal and optionally also slidable manner. Only a few degrees of articulated freedom, between 0° and 5°, are sufficient to securely position the two shells 101 and 102 on most human heads.To accommodate different head sizes, the cups 101 and 102 can be slidably guided in the part 103.

[0017] Fig. Figure 2 shows a view into the inner shells of the device 100 for stimulating hair growth. Fig. 1. The two shells 101 and 102 contain individual electrodes 105, here between five (shell 101) and six (shell 102) in number, which are assembled as a bundle electrode from different electrodes. The bundle electrodes enable at least one electrode 106 within the individual electrode 105 to make contact with the skin on the human head when the device 100 is worn as intended. The individual electrodes 105 are located in a bellows made of rubber, silicone, or another elastomer. Each individual electrode 106 is elastically held within the individual electrode 105. Detail A, marked in this figure, is shown enlarged in the next figure.

[0018] In Fig. 3a is a detail from Fig. Figure 2 shows an enlarged representation of a first embodiment. This consists of a metallic electrode 106, which is held in a receiving device 107, such as a rubber grommet or a grommet made of silicone or another elastomer. This metallic electrode 106 is open at the top and, during intended use of the device 100, comes into contact with human skin. Upon contact, the receiving device can deform elastically, so that the metallic electrode 106 is only pressed against the scalp. Inside the receiving device is a flexible wire to galvanically connect the metallic electrode 106 to a control device.

[0019] In Fig. 3b is a detail from Fig. Figure 2 shows a second embodiment enlarged. Instead of a metallic electrode 106, which is received in an elastic receiving device 107, the electrode 107' is made of a conductive elastomer. This can be conductive rubber or other elastomers that conduct electricity due to their chemical composition.

[0020] Fig. Figure 4 shows a flowchart of a control device 200. The central element of the control device 200 is a multiplexer that can simultaneously supply one anode and one cathode with electric current. In a very special embodiment of the control device 200, the multiplexer can also supply more than one pair of electrodes 106 with electric current. The electrodes 106 of the different pairs should not have a connecting path along which an electric current flows that crosses a connecting path of two other electrodes that are activated at the same time. This prevents unwanted stray currents from flowing in the scalp. The multiplexer is connected to a pulse generator that produces the electrical impulses.The pulse generator, connected to the electrodes via the multiplexer, outputs the applied voltage and a current signal to a microcontroller via an analog feedback line. The microcontroller derives control signals from this to control the pulse generator with respect to voltage amplitude, current, charge flow, frequency, and pulse duration. This control takes place via the digital input / output (digital I / O) line. The microcontroller controls the multiplexer via a digital bus to programmatically or randomly pair different electrodes 106, which are connected to the cathode and anode outputs of the multiplexer.

[0021] Fig. Figure 5 shows various electrode pairing patterns in the device for stimulating hair growth. In the embodiment shown here, the individual electrodes are connected as fixed cathodes and anodes with a distribution as shown in the lower center. However, in a further embodiment of the invention, it is also possible to selectively switch individual electrodes as either anodes or cathodes using the multiplexer. In a first program P1, which is shown here as an example, the control device with multiplexer pairs a single electrode 105 with other single electrodes 105 at a time offset, so that electrical stimulation of hair growth in the scalp occurs approximately along the connecting lines shown here in bold. To perform the stimulation symmetrically, the control device can alternately activate the electrode pairs shown by the bold connecting lines.The same conditions apply to the stimulation programs P1, P3, P4 and P5 shown here as examples.

[0022] In program P1, as many cathode-anode pairs as possible are formed to achieve the broadest possible stimulation. In program P2, the cathode-anode pairs are paired along frontal lines (in relation to the planes of the human body: sagittal, frontal, and transverse), including pairing cathodes and anodes that are far apart. In program P3, adjacent cathodes and anodes are paired to achieve stimulation along frontal and sagittal lines. Program P4 deliberately generates asymmetrical stimulation patterns, for example, to stimulate the upper scalp in an asymmetrical pattern if hair loss is asymmetrical. Finally, program P5 shows how individual cathode-anode pairs are paired within each of the two dishes 101 and 102.

[0023] In Fig. Figure 6 shows a pulse diagram for a stimulation pulse. Within a pulse sequence consisting of an anodic stimulation signal with the indicated anode signal duration, a subsequent time-out period, and a subsequent cathodic stimulation signal with the indicated cathode signal duration, three states exist: polarization during the anode signal with the indicated anode signal duration, a relaxation period or time-out period, and depolarization during the cathode signal with the indicated cathode signal duration. The cathode signal with the indicated cathode signal duration is followed by another time-out period until a new cycle begins. This cycle can be repeated on an existing electrode pair, or a different electrode pair can be activated to begin the next stimulation cycle.

[0024] Fig. Figure 7 shows a diagram illustrating different stimulation frequencies. It depicts the duration between two stimulation cycles consisting of polarization, relaxation, and depolarization (see Figure 7). Fig. 6) The duration can range from t = 1 / (10 Hz) through t = 1 / (9 Hz), t = 1 / (8 Hz), t = 1 / (7 Hz), and t = 1 / (6 Hz) down to 1 / (5 Hz). The length of a polarization / depolarization pulse as a stimulation pulse ranges from t = 1 / (25 Hz) to t = 1 / (5 Hz). The stimulation frequency, with electrode pair changes, can range between 5 Hz and 10 Hz. REFERENCE MARK LIST 100 Device for stimulating hair growth 101 bowls 102 bowls Part 103 105 single electrode 106 electrode 107 Recording device 107' Electrode, conductive rubber 108 strands 200 control device

Claims

[1] Device (100) for stimulating hair growth, comprising - a plurality of electrodes (106) for electrical stimulation of the skin, wherein a control device (200) connected to the plurality of electrodes (106) triggers electrical stimulation impulses via the electrodes (106), characterized by , that the control device (200) alternately pairs two electrodes (106) of the plurality of electrodes (106) as cathode and anode and applies electrical stimulation impulses, wherein the device is constructed in three parts, wherein - a first part is formed as a shell (101) covering the front of the head, - a second part is formed as a shell covering the back of the head (102), and - a third part (103) jointly connects the shell (101) covering the front of the head and the shell (102) covering the back of the head. [2] Device according to claim 1, characterized by, that the control device (200) pairs different electrodes (106) of the plurality of electrodes (106) successively over time. [3] Device according to claim 1 or claim 2, characterized by , that controlled by the control device (200), the anode of a pair of two electrodes (106) directs an anodic stimulation pulse onto the skin for a first period of time, which is met by the other electrode with a potential of 0V, and The cathode of a pair of two electrodes (106) directs a cathodic stimulation pulse onto the skin for a second period following the first period, which is met by the other electrode with a potential of 0V. [4] Device according to claim 3, characterized by , that between the two stimulation pulses both electrodes (106) have a potential of 0V. [5] Device according to any one of claims 1 to 4, wherein the stimulation pulses have a duration between 1 / 25 s and 1 / 5 s, the frequency of the stimulation pulses being between 5 Hz and 10 Hz. [6] Device according to any one of claims 1 to 5, characterized by , that the control device (200) pairs two electrodes (106) from different shells (101, 102) together. [7] Device according to any one of claims 1 to 5, characterized by , that the control device (200) pairs two electrodes (106) made of identical shells. [8] Device according to any one of claims 1 to 5, characterized by , that the control device (200) pairs two electrodes (106) together for only a single pulse sequence of anodic stimulation pulse and cathodic stimulation pulse, then pairs two other electrodes together.

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