Patent Description:
It is known that ultrasound therapy improves peripheral blood circulation, tissue nutrition, and accelerates blood flow.

No. <CIT> discloses an ultrasonic foot massager comprising two piezoelectric transducers embedded in a insole of a person's shoe coupled to an ultrasonic excitation generator. The first and the second piezoelectric ultrasonic transducers are coupled to the first and the second groups of ultrasound generating transducers, respectively. Disadvantage of the specified device is that a large number of small-sized piezoelectric transducers of high ultrasonic frequency are used to create ultrasonic frequency oscillations (<NUM> units in the first group of ultrasonic generating transducers, and <NUM> in the second group of ultrasonic generating transducers), and a complex multi-channel controller is used to excite them.

<CIT> discloses a device for effect of acoustic waves on organs of a human body. The device comprises acoustic vibrators mounted on a special stand that can be mechanically adjusted so that the acoustic pulsations are directed locally to the intended place of body therapy, for example, blood vessels in lower legs, which results in the activation of blood flow in tissues of human legs. Effect of the indicated device promotes blood circulation in the tissues of human legs, but does not affect capillary tissues in feet, which is especially important for diabetic patients.

International patent application, publication No. <CIT>, represents the closest prior art and discloses systems and methods including wearable, non-invasive ultrasound modalities for treating a variety of medical conditions, including but not limited to peripheral vascular disease. The modality could be therapeutic ultrasound (TUS), and be configured to promote angiogenesis within a patient via stimulation of cavitation and shear stress, among other mechanisms.

The invention does not have the above-mentioned disadvantages and is associated with additional advantages, i.e. increases effectiveness of blood circulation stimulation.

The present invention is directed to a leg blood flow stimulation system and a method for combining low and high frequency acoustic in the system according to claims <NUM> and <NUM>, respectively. Additional features and embodiments of the invention are defined in the dependent claims.

The leg blood flow stimulation system comprises a closed chamber, bimorph type piezoelectric transducers in the closed chamber, in-chamber speakers built into side walls of the chamber and connected to same controller to which the bimorph piezoelectric transducers are connected.

The leg blood flow stimulation system is designed so that a person's legs up to knees can be placed in a closed chamber and encased in a standard type of elastic splint type system. Feet are affected by bimorph-type piezoelectric transducers connected to a controller, and the lower legs are affected by acoustic vibrations due to the speakers installed in the side walls of the closed chamber. The pulses sent from the controller control synchronous operation of bimorph piezoelectric transducers and acoustic speakers activating blood flow in tissues of human legs and increasing efficiency of blood flow stimulation.

Features of the invention, which is new and inventive are given in the Claims. However, the invention may be best understood from the following detailed description of the invention, in which, without limiting the scope of the invention, embodiments of the invention are given in conjunction with the accompanying drawings, where:.

It should be understood that numerous specific details are presented in order to provide a complete and comprehensible description of the invention embodiment. However, the person skilled in art will understand that the embodiment examples do not limit the application of the invention which can be implemented without these specific instructions. Well-known methods, procedures and components have not been described in detail for the embodiment to avoid misleading. Furthermore, this description should not be considered to be constraining the invention to given embodiment examples but only as one of possible implementations of the invention as disclosed in the appended claims.

The leg blood circulation stimulation system according to the invention and as shown in <FIG> for stimulation of blood circulation in a human leg (<NUM>) comprises: a closed chamber (<NUM>), speakers (<NUM>) arranged on sides of the closed chamber (<NUM>) that excite acoustic vibrations, and a matrix of piezoelectric bimorph transducers (<NUM>) installed in a plane of the closed chamber (<NUM>) corresponding to the plane of feet.

The matrix of bimorph piezoelectric transducers comprises a base (<NUM>) for example a rigid plastic plate with two to six piezoelectric bimorph transducers (<NUM>). Each piezoelectric bimorph transducer (<NUM>) consists of a thin, up to <NUM> thick, and a round, up to <NUM> diameter, metal plate rigidly and concentrically connected-glued to a thin, up to <NUM> thick, and round, up to <NUM> diameter, piezoelectric plate. Piezoelectric bimorph transducers (<NUM>) are placed in two support zones of a sole of the foot - in the area below toes and the heel area. Each of the mentioned areas comprises from one to three piezoelectric bimorph transducers (<NUM>).

In the piezoelectric bimorph transducers (<NUM>) ultrasonic frequency resonant oscillations of higher modes with a frequency range of <NUM> to <NUM> are excited. Piezoelectric bimorph transducers (<NUM>) are elastically and concentrically attached to the base (<NUM>) of the transducer matrix through round holes where the diameter of a hole is <NUM> smaller than the diameter of the round metal plate of the transducer (<NUM>). Free surface of the piezoelectric plate faces exposed surface of the sole of the foot. This allows the transducer (<NUM>) to make direct contact with the sole and induce acoustic vibrations in it.

The speakers (<NUM>) are placed symmetrically on both sides of the leg (<NUM>), facing each other. Number of speakers on one side of the leg (<NUM>) can be in the range from one to three.

Stimulation of blood circulation in the leg (<NUM>), particular in the area of the lower leg, is carried out by exciting low-frequency, from <NUM> to <NUM>, acoustic vibrations with speakers (<NUM>) powered by a first generator (<NUM>), and the high-frequency, from <NUM> to <NUM>, vibrations in the feet through piezoelectric bimorph transducers (<NUM>) powered by a second generator (<NUM>). Generators (<NUM>, <NUM>) are controlled by one controller (<NUM>).

The leg blood flow stimulation system is designed in such a way that the blood flow of the leg (<NUM>) below the knees is affected by the acoustic field without causing external effects on human internal organs. The acoustic energy of low-frequency sound, from <NUM> to <NUM>, and high-frequency ultrasound, from <NUM> to <NUM>, has little attenuation in biological tissue and effectively affects both external and deeper biological tissues, at a depth of up to <NUM>. In this range of ultrasonic frequencies the piezoelectric bimorph transducers (<NUM>) excite the acoustic field of maximum intensity.

The acoustics generated by bimorph transducers (<NUM>) and speakers (<NUM>) to different areas of the leg (<NUM>) can occur simultaneously or separately. The acoustics of the speakers (<NUM>) affect the blood flow of the large blood vessels of the lower leg, while the ultrasonic acoustics affect the small blood vessels/capillaries of a foot and nerve tissues of the sole.

One or both legs (<NUM>) of a person are placed in the closed chamber (<NUM>), which is hermetically sealed to protect environment from transmitted noise, so that the foot or feet rests on the matrix of piezoelectric bimorph transducers (<NUM>). Signals sent from the controller (<NUM>) to the generators (<NUM>, <NUM>) are used to excite low and high frequency vibrations in the human legs (<NUM>), which activates and stimulates blood flow in the legs (<NUM>).

By placing both, or only one, of the patient's legs (<NUM>) in the closed acoustic chamber (<NUM>), transmitting low frequency and ultrasonic frequency can be performed simultaneously, by turns, or only one of those frequencies. When the first generator (<NUM>) is turned on, which excites low-frequency acoustic waves through the speakers (<NUM>), surface of the lower leg and its deep tissues and blood circulation are affected. Depending on assigned program, by changing the amplitude, phase and signal duration of the electrical signal supplied to each speaker (<NUM>) it is possible to excite an acoustic field of intensity that is constant or variable according to a certain rule, e.g. harmonically pulsating or intermittent, in the closed chamber (<NUM>), as well as to excite an acoustic wave that travels from top to bottom or from bottom to top with respect to the leg. When the second generator (<NUM>) is turned on, which excites ultrasonic frequency acoustic waves through piezoelectric bimorph transducers (<NUM>), surface of the sole of the foot and its deep tissues and blood circulation are affected. In this case, each piezoelectric bimorph transducer (<NUM>) is excited by resonant higher-mode oscillations, and by changing the amplitude and duration of the electric signal supplied to each transducer (<NUM>), it is possible to excite an ultrasonic field of constant or variable intensity on the surface of the sole, as well as to excite a running ultrasonic field wave if at least three piezoelectric bimorph transducers (<NUM>) are installed in the base (<NUM>) of the transducer matrix.

The closed chamber (<NUM>) must comfortably accommodate both legs (<NUM>) from feet to knees of a seated adult with legs (<NUM>) bent at the knees. Body of the closed chamber (<NUM>) is preferably made of rigid structural material, such as reinforced plastic or metal, its interior is lined with sound-absorbing material, and the speakers (<NUM>) attached to both sides of the closed chamber (<NUM>) are additionally acoustically isolated from the outside so as not to spread noise to the environment. As an example, internal dimensions of the closed chamber (<NUM>) are: length - <NUM>; width - distance between speakers is <NUM>; height - <NUM>.

Depending on the assigned program, by changing the amplitude, phase and signal duration of the electric signal supplied to each speaker (<NUM>), an acoustic field of constant or variable intensity according to a certain rule, e.g. harmonically pulsating or intermittent, can be excited in the closed chamber (<NUM>) as well as a traveling acoustic wave, top-down or bottom-up relative to the leg (<NUM>). The distance of <NUM> between the loudspeakers (<NUM>) located on the opposite sides of the closed chamber (<NUM>) allows the phenomenon of a standing acoustic wave of the same length to be excited in the closed chamber (<NUM>) which is obtained by exciting the speakers (<NUM>) with a frequency signal of about <NUM>. Thus due to the superposition of two identical acoustic waves emanating from the opposite sides an acoustic field of about twice the intensity than near the speakers (<NUM>) is created in the central zone of the closed chamber (<NUM>), increasing the acoustic effect on the leg (<NUM>). Minimum distance between the calf of the leg (<NUM>) and the speaker (<NUM>) is about <NUM>. This ensures that the legs (<NUM>) are positioned in the central area of the closed chamber (<NUM>) and do not interfere with the speaker (<NUM>) generating the acoustic waves.

The system is most suitable for human lower limbs for several reasons. First, the main blood vessels are positioned shallowly enough and in case of any type of insufficiency of their function, it is not difficult to influence their function, which is not only local, but also systemic, due to the antero-retrograde effect through the vagus-sympathetic system innervating them. Second, there is an important effect on microcirculation, which is realized through the mechanical and partially thermal effects of ultrasound. Third, the effect was determined not only on the functional regulation of blood vessels, but also through the effect on blood-forming elements, i.e. modifying the function of platelets in the desired direction - reducing thrombogenesis as a thromboembolic factor or increasing it in case of a threat of hemorrhages. Fourth, since in diabetes, the red blood cells, which have a diameter of about <NUM> micrometers, become stiffer, it is more difficult for them to move in the blood stream in the capillary channels, which have a diameter of about <NUM> micrometers. As a result, the capillaries become clogged, slowing down the blood supply to the human limbs. Under the influence of ultrasonic vibrations, the coefficient of friction between the red blood cell and the capillary is reduced from static to kinematic, which is <NUM> percent lower, thus facilitating translational motion of the stiffer red blood cells and, at the same time, blood flow.

The system can be used in the presence of pathology of the main vessels of the lower limbs of various origins, especially after reconstructive operations in the case of diabetic angiopathy and, most importantly, in the case of microcirculatory dysfunction associated with tissue perfusion disorders, characteristic of the highly traumatic "diabetic foot" syndrome, often leading to amputations and irreversible disability.

Claim 1:
A leg blood flow stimulation system comprising means for stimulating acoustic vibrations, a closed chamber (<NUM>), speakers (<NUM>) for exciting low-frequency acoustic vibrations, located on sides of the closed chamber (<NUM>), a matrix comprising piezoelectric bimorph transducers (<NUM>) for exciting high-frequency vibrations, where the matrix is arranged in the closed chamber (<NUM>), in a plane of the closed chamber (<NUM>) corresponding to a plane of a foot, corresponding to a support zone of a sole below toes and support zone of a heel, where each zone comprises from one to three piezoelectric bimorph transducers (<NUM>), a controller (<NUM>) for controlling the first generator (<NUM>) and the second generator (<NUM>) at the same time characterized in that the leg blood flow stimulation system further comprises
a first generator (<NUM>) for powering the speakers (<NUM>) for exiting low-frequency acoustic vibrations,
a second generator (<NUM>) for powering the piezoelectric bimorph transducers (<NUM>) for exiting high-frequency vibrations,
wherein the
body of the closed chamber (<NUM>) is made of a rigid structural material where interior of the chamber (<NUM>) is lined with a sound-absorbing material, and speakers (<NUM>) attached from both sides of the closed chamber (<NUM>),
wherein the internal dimensions of the closed chamber (<NUM>) are: length - <NUM>; width, distance between the speakers (<NUM>), - <NUM>; height - <NUM>,
speakers (<NUM>) for exciting low-frequency acoustic vibrations, located on sides of the closed chamber (<NUM>),
wherein the frequency of the low-frequency acoustic vibrations generated by the speakers (<NUM>) is from <NUM> to <NUM>,
wherein the frequency of the high-frequency vibrations generated by the piezoelectric bimorph transducers (<NUM>) is from <NUM> to <NUM>,
wherein the piezoelectric bimorph transducers (<NUM>) are elastically and concentrically attached to the to round holes formed in a base (<NUM>) of the matrix of transducers, the diameter of each round hole is by <NUM> smaller than diameter of metal plate of each transducer (<NUM>) where surface of the metal plate of each transducer (<NUM>) free from a piezoelectric plate is directed to surface of the sole,
wherein each piezoelectric bimorph transducer (<NUM>) comprises a thin, up to <NUM> thick, and a round, up to <NUM> diameter, metal plate rigidly and concentrically connected-glued to thin, up to <NUM> thick, and round, up to <NUM> diameter, piezoelectric plate.