The present description relates to a system for aesthetic treatment of a human cutaneous and subcutaneous tissue and in particular for treatment of large segments of tissue.
Tissue is frequently treated non-invasively by different energies delivered to the skin. Types of energies that may be found in use for skin treatment include ultra sound (US) energy, Radio Frequency (RF) energy, microwave (MW) radiation or radiation energy emitted by a source of light or heat. The skin treatment energy is coupled to the skin by an applicator. The spot-size of the applicator is the area of the interface for delivering the energy and it defines to some extent the segment of skin or tissue to which the skin treatment energy is transferred. In order to treat another skin segments, the applicator is repositioned or re-aligned across a larger segment of the skin and activated to couple treatment energy to this segment of skin. The size of a treated segment of skin varies from about 3×3 mm2 to about 30×30 mm2.
After applying treatment to a specific skin segment the remaining segments of the skin are treated by moving or repositioning the applicator across a larger skin segment. A caregiver providing the skin treatment manually repositions the applicator. Although the time of skin treatment energy delivery could be controlled, other parameters would much depend on the expertise of the caregiver such as treated area overlap, quality of the contact, pressure applied to the applicator etc . . . As a result, not all skin segments are treated uniformly and evenly.
The human or animal skin has a three-dimensional contour and in addition to the caregiver errors, the skin contour complicates proper applicator positioning on the skin and optimal coupling or delivery of tissue or skin affecting energy.
The skin treatment usually continues for tens of minutes (20-60 minutes) depending on the treatment area size and naturally causes some fatigue to the caregiver. Reliance on the caregiver expertise for repositioning of the applicator frequently causes some of the skin treated areas to receive a lower than desired portion of energy and be at a temperature lower than the optimal treatment temperature, while other skin areas could receive a larger than desired portion of energy and be at a temperature higher than the optimal treatment temperature.
The term “skin” as used in the present disclosure includes the outer skin layers such as stratum corneum, dermis, epidermis, connective tissue and the deeper subcutaneous layers such as adipose tissue. The terms “tissue” or “skin” as used in the present disclosure have the same meaning and are used interchangeable through the text of the disclosure.
The term “skin treatment energy” as used in the present disclosure means electromagnetic energy delivered to the skin by a treatment energy application device.
The term “treatment energy source” may be a laser source, for example a semiconductor laser such as laser diode, VCSEL, an assembly of laser diodes or bars or a solid state laser such as an Nd:YAG or Alexandrite for example, or a fiber laser, or other laser source or sources. The treatment energy source may be a broad spectrum light source of either coherent or non-coherent radiation source such as a Xe, Kr, W, Quartz-Iodine lamps or a high power LED. In some examples the treatment energy source maybe microwave energy source or sources.
The term “scanning angle” as used in the present disclosure means half the angle between the extreme scanning beam locations on the skin of the incident treatment energy beam and the energy source or scanning mirror/deflector. In the case the energy source is a ultrasound phased array the “scanning angle” will mean half the angle between the extreme scanning locations of the incident treatment energy beam on the skin and the phase center of the array, which is the location that the radiation appears to emanate. The scanning angle defines the length of a treatment energy beam sweep on the skin. In some examples the scanning angle of the same scanning system could be a variable angle characterizing a shorter or a longer treatment energy beam sweep.
The term “incidence angle” as used in the present disclosure means an angle between the treatment energy beam and the skin at each of the locations the beam impinges the skin.
The term “tissue/skin affecting energy” or “treatment energy” as used in the present disclosure means energy capable of causing a change in the tissue including heating and affecting hair follicles, hair papillae, sebaceous glands, fat cells, blood vessels, connective tissue, or supporting such change. Such energy for example, may be optical radiation in visible or invisible part of electromagnetic spectrum. The exact parameters of the energy source such as power, fluence, wavelength, etc., may be chosen depending on the specific application and clinical effect to target tissue.
The term “target tissue temperature” as used in the present disclosure means temperature of the targeted tissue such as dermis, hair follicle, hair papillae, sebaceous glands, fat cells, blood vessel, pigmented lesion, adipose or deeper subcutaneous tissue. The temperature of the target tissue could be derived based on the temperature of the skin overlaying the target tissue.
The term “computer” as used in the present disclosure means a computer including a processing unit capable of receiving data or information, processing it, and delivering the data processing results to another device. As such, a computer may include, as non-limiting examples, a personal computer, a PDA computer, a mobile telephone, a micro controller and similar devices. Typically, a computer as defined herein would have a display or communicate with a display. The display could be a touch type of display such that the caregiver could use the display to enter commands or a monitor screen that displays information and images.
The term “three-dimensional (3D) Acquisition system” as used in the present disclosure means a device that acquires data to reconstruct a surface contour. It may include one or more cameras and may include a projector to project a light structure.
A system for skin treatment including a treatment energy source that generates a treatment beam. A treatment beam deflecting mechanism is configured to direct the treatment beam to a treated skin area. One or more video cameras are configured to capture a treated skin area and communicate the captured treated skin area image to a processor. The processor is configured to construct, based on a captured treated skin area a three-dimensional (3D) representation of the captured treated skin area. The processor is further configured to control a treatment beam deflecting mechanism to deflect the treatment beam to follow the three-dimensional representation of the captured skin area.
The system for skin treatment includes an infrared imager configured to capture an infrared image of the treated skin area captured by the at least one video camera and communicate the infrared image of the treated skin area to the processor. Based on the infrared image of the treated skin area, the processor is also configured to assess the temperature of adipose tissue located below the treated skin area.
Disclosed is also a method of skin treatment. The method includes providing a treatment energy source for generating a treatment beam and employing a scanning mechanism to scan the treatment beam across a three-dimensional skin area to be treated. The method is employing a temperature sensing device configured to sense a temperature of the skin area to be treated and uses a processor configured based on the temperature of the skin area to assess at least the temperature of adipose tissue located below the skin area to be treated.
Currently, most of the skin treatments by electromagnetic energy and in particular by light are performed by an applicator that when applied to the skin affects an area of 3×3 mm2 and up to 30×30 mm2. In order to treat other skin segments or areas, the applicator is repositioned or re-aligned across a large segment of the skin and activated to deliver or couple tissue or skin affecting or treatment energy to this segment of skin. Proper skin treatment and in particular adipose tissue treatment for circumference reduction would provide better results if efficient, homogenous affecting energy delivery over a relatively large skin areas or segments could be performed.
It has been found that it would be advantageous to affect simultaneously or almost simultaneously a large skin area without involving hand motion and applicator repositioning by the caregiver.
The present disclosure suggests an efficient, homogenous and almost simultaneous skin treatment energy delivery apparatus and method over a relatively large skin areas or segments of skin. Treatment energy beam scanning provided by a deflecting mirror or a rotating polygon supports almost simultaneous delivery of the skin treatment or skin affecting energy across a large area of skin. Overlap of the scanning spot formed by the treatment energy beam along the scanning path removes non-uniformities caused by any none-uniform energy distribution or hot-spots in the treatment energy beam pass. Application of treatment energy by scanning the treatment energy beam makes the skin treatment less dependent or almost not dependent on the caregiver's expertise and reduces the treatment time considerably.
An additional advantage of the treatment energy beam scanning is that it supports variability in position of the scanning spot in all three dimensions/axes. Treatment energy beam spot could be easily positioned at almost any location on the skin in X-Y plane and also moved over relatively large distance in direction of Z axis or depth.
The need to accurately identify the temperature readings or representation of target tissue temperature across the treated skin area under such conditions may represent a serious challenge to any caregiver. The present document also discloses a method of target tissue temperature determination in course of the skin treatment.
As light energy is absorbed rapidly when penetrating the skin, heating of the superficial layers of the skin is inevitable. In order to eliminate the risk of undesired harmful effect of the epidermis and dermis one may use a number of cooling methods such as contact cooling, dynamic-cooling, air-cooling, cryogenic cooling and other known in the art cooling methods. These epidermal protection methods cool the skin in any combination of before, during and after the delivery of light energy to the skin. So the temperature rise within the epidermal and dermal layer is below the threshold of harming the tissue, while still reaching desired treatment temperature in the targeted tissue.
Monitoring the temporal change of the skin temperature could be done by using a thermal camera, IR temperature sensor, ultrasound propagation speed temperature monitoring, contact temperature sensors, non-contact temperature sensing device, or any other means that can be used to assess the temperature in the target tissue. This could be achieved by measuring the amount of heat that has dissipated from the target to the skin and then cooled by either normal air convection of the skin or by taking into account the temporal dynamics of bio-heat equation for the entire treated skin area.
Another advantage of using a scanning treatment energy beam is the ability for continuous control of a large number of variables available in course of the skin treatment. This could include distribution of energy in each of wavelengths of the treatment radiation beam, the spot/area formed by irradiating the skin treatment beam, overlap between two neighbor treatment spots, treatment energy level, exposure duration per unit area or continuous irradiation, selected treatment duration and adaptation to treated skin/tissue area characteristics.
In some examples, the energy dose delivered by a scanning treatment beam spot could be set to cause immediate detectable temperature rise of the treated tissue. In other examples of the method and apparatus disclosed, the energy dose delivered by a scanning treatment beam spot could be set to cause a slow, immediately not detectable temperature rise of the treated tissue, such that the treated and surrounding tissue is heated but not damaged.
The scanning system could deliver the treatment energy in a continuous or pulsed mode. Uniform scanning treatment beam intensity or fluence distribution and location on the treated skin area among others could be regulated by processor 218 (
In a further example, the treatment beam scanning speed could be set to match the thermal relaxation time and perfusion rate of the targeted skin/tissue, such as dependent on the size of the treated area and desired temperature to be maintained, or a homogenous desired skin temperature is maintained for a certain volume of targeted tissue.
Reference is made to
When treatment energy beam 108 is directed to scan across the skin the actual spot size produced by the treatment beam intensity may change due to change in the incidence angle and the skin curvature at any location on skin, the fluence of the treatment energy changed in order to compensate and reach the desired treatment energy intensity by temporarily increasing the source power.
A computer 216 that includes a processor 218 which controls position of the scanning mechanism 212 and is configured to locate treatment beam scanning spot 220 at any coordinate in scanning plane 224. Processor 218 also controls the scanning mechanism 212 to produce a plurality of treated skin area scanning patterns and further controls the scanning speed of treatment scanning spot 220 and treatment energy source operation time. Control module 216 and in particular processor 218 controls all elements of system 200 including operation time and parameters of treatment energy source 204. It has been noted above that the human or animal skin usually has a three-dimensional contour or profile. In one example, system 200 includes a dynamic focus module 228, such as HPLK or Pro-series module, commercially available from Cambridge Technology, Inc., Bedford, Mass. 01730 U.S.A. However, in the current disclosure the Dynamic Focus Module (DFM) is used to follow the three-dimensional contour or profile of the human skin and not to flatten the X-Y plane. In order to compensate for any change in the curvature of the skin and deliver the prescribed fluence or power dose, the treatment radiation beam divergence could be changed. The change in divergence would cause a change in the spot size and changes to the treatment radiation intensity delivered by the scanning spot could be introduced. By changing treatment radiation beam 208 divergence, the diameter of the scanning spot 220 could be changed up to ten times or even more. The diameter of spot 220 could change for example, from 5 to 30 mm.
The scanning or treatment energy beam sweep angle and 3D (three dimensional) nature of human body distort to certain degree the scanning treatment spot shape and cause a treatment beam intensity roll-off at peripheral treatment beams. Scanning treatment energy spot shape distortion could be compensated among others by changing the size of the scanning spot and/or the amount of fluence delivered into the treatment energy radiation beam. The amount of fluence or intensity delivered into the treatment radiation beam could be compensated by providing a treatment intensity roll-off look-up table or by calculating the change in energy in real-time. Based on the treatment intensity roll-off look-up table processor 218 adjusts the deflected treatment energy beam intensity to maintain a roll-off the treatment energy beam intensity or fluence of less than 10% (10 percent). The look-up table is calculated based on the skin 3D contour and the treatment energy beam incidence angle that is usually less than 30 degrees. The scanning system could deliver the treatment energy in a continuous or pulsed mode. Uniform scanning treatment radiation beam distribution on the treated skin area among others could be regulated by processor 218 (
System 200 further includes a 3D acquisition system 232 (For example, video cameras 232-1 and 232-2) configured to capture a treated skin area or segment and communicate the captured treated skin area image to processor 218. The 3D acquisition system 232 also communicates the captured image or images to processor 218, which based on the communicated image or images is configured to reconstruct/determine the three-dimensional (3D) contour of the treated segment or area of the human body. The 3D acquisition system 232 could be equipped with an optical zoom system supporting imaging of different sizes of the treated skin area or segment. Processor 218 is also configured to construct based on the captured skin area a three-dimensional representation or topography of the captured skin area. Processor 218 is further configured to control the treatment energy beam deflecting mechanism to deflect the treatment energy beam to follow the topography or three-dimensional representation of the captured skin area.
System 200 further includes one or more infrared (IR) cameras or imagers 236 configured to provide processor 218 with a thermal image of the skin affected by the treatment energy radiation. Infrared imager 236 could be almost any infrared camera supporting temperature sensitivity of 1° K or better. Infrared imager supports non-contact and non-invasive skin temperature measurement. IR imager or camera 236 could have a resolution sufficient to support imaging of an area of the treated skin segment with dimensions of 30×30 cm2 or smaller. Processor 218 is configured to receive the thermal image indicating temperature distribution on the surface of the currently treated by the treatment energy beam skin segment and determine the temperature of the currently treated skin area or segment. Physical properties of human tissue are known and relatively well established. Temperature distribution below the skin surface can be calculated based on skin surface temperature and finite elements analyses, using the Bio-heat equation or other suitable numerical and statistical methods known for solving the different heat distribution equations.
(For Bio-heat equation details see H. H. Pennes, Analysis of Tissue and Arterial Blood Temperature in the Resting Human Forearm, J. Appl. Phys. vol. 1, pp. 93-122, 1948 and incorporated in its entirety in the present description.)
Methods of assessing temperature inside the body by analyzing the radiation reflection spectrum or any other known in the art method could be used to assess temperature of the adipose tissue located below the skin. Real-time temperature monitoring facilitates safe and effective skin treatment.
Imager or infrared camera 236 could be equipped by an optical zoom system supporting imaging of a large area or segment of the treated skin or a small area of the treated skin segment.
System 200 further includes a display 240. Processor 218 based on the signals received from the infrared imager 236 continuously or at predetermined intervals updates the displayed thermal image of the treated skin segment. Based on the signals received from the 3D acquisition system 232, processor 218 issues corrections to the treatment energy spot and treatment energy beam location to follow the skin contour.
Display 240 is configured to receive from processor 218 the thermal image of the treated skin segment and to display the temperature of the skin segment or thermal map 300 (
Display 240 is also configured to receive from computer 218 processor 216 (
In some examples control of the treatment process and of the scanning system could be simplified by forming a specific scanning geometry, for example, limiting the treatment energy beam incidence angle to 20, 15 or 10 degrees. At such treatment energy beam incident angles, scanned treatment energy power is almost constant and skin topography does not change significantly.
In
According to another example, control of the distance between the scanning mechanism and the treated skin surface could be performed based on the dimensions/size of the treated body. Image sensors, such as video cameras 232 (
In some examples the treatment process settings and control could be simplified by using prepared ahead of time standard skin treatment procedures parameters. The procedures could be stored in the memory as a Look-up-Table (LUT) of computer 216 (
While the method and apparatus have been particularly shown and described with references to some examples thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the method and apparatus encompassed by the appended claims.
Filing Document | Filing Date | Country | Kind |
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PCT/IL17/50005 | 1/1/2017 | WO | 00 |
Number | Date | Country | |
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62286458 | Jan 2016 | US |