LASER TREATMENT COOLING HEAD

Abstract: A cooling head (1) for a skin treatment laser has a body (2) with a mount (3) at one end for attachment to a laser head (12). A cooling surface (4) at the other end is used for application to a patient's skin, and a coolant chamber (5) is disposed between the mount and the cooling surface. The chamber has wall portions (60, 61) transparent to non-visible laser light to allow a laser beam to be passed from the mount to the patient's skin through the cooling surface. A coolant inlet (9) and outlet (8) provided in the body enable the supply and removal of coolant in order to cool the cooling surface and an extraction port (42) enables removal of debris from the treatment area and is connected to a vacuum source. A window (100) is provided in the body optically transparent in the visible light range to allow the laser beam at the cooling surface to be viewed.

Description: 1 LASER TREATMENT COOLING HEAD The present invention relates generally to means of cooling the surface of skin during laser treatment (resurfacing) , the aim being to reduce the sensitivity to pain, reduce the need for anaesthetic or both. More particularly, the present invention relates to a laser treatment cooling head and, particularly, to a cooling head which can be used with a C0 2 or other laser employed for laser resurfacing of a patient's skin. The advent of easily usable laser equipment has led to a great increase in this kind of treatment, but the problem of the control of pain, which can be severe as the process is essentially one of burning away skin, remains an obstacle to the wider use of the technique. In particular, according to clinical judgment and patient tolerance of pain, a general or local anaesthetic may be necessary. The use of a general anaesthetic enables the clinician to proceed rapidly with the treatment without constant checking of the comfort of the patient, but carries the severe drawbacks of the well known trauma of general anaesthetics, including the risk and the need for a recovery time before the patient resumes normal life, the need for an anaesthetist and the time for preparation and recovery. The latter two, in particular, make the cost of the treatment very high. In contrast, use of a local anaesthetic can allow a dermatologist to administer the anaesthetic, but again there are drawbacks. Pain control over certain areas of the body, particularly the face, requires multiple injection sites which is traumatic for the patient and the need for top-up doses during treatment is also unpleasant for the patient, also slowing down the 2 treatment. The total dose of local anaesthetic is also limited which can therefore limit a particular treatment session, thus requiring further sessions and associated increased cost. It has been proposed to use localised cooling to overcome the problems of anaesthesia and. In particular, it has been proposed to utilise a flow of coolant through a laser-transparent glass chamber which can be held against the skin while the laser treatment is carried out. However, this is only possible with visible light lasers, not with C02 or Erbium YAG (yitrium aluminium garnet) lasers, as existing cooling devices use coolants and windows that are not lucent to the wavelengths of C02 or Erbium YAG radiation, i.e. current cooling devices using water would absorb the energy at these wavelengths so skin treatment would be impossible. According to the present invention, there is provided a cooling head for a skin treatment laser, the cooling head comprising a body having a mount at one end for attachment to a laser head to secure the body relative to the head in a fixed position; a cooling surface at the other end for application to a patient's skin; a coolant chamber disposed between the mount and the cooling surface, the chamber having wall portions transparent to C0 2 , Erbium YAG or other non-visible laser light to allow a laser beam to be passed from the mount to the patient's skin through the cooling surface, and 3 a coolant inlet and outlet provided in the body to enable the supply of coolant to and the removal of coolant from the body in use in order to cool the cooling surface; an extraction port for enabling removal of debris from the treatment area and for connection to a vacuum source; and a window in the body optically transparent in the visible light range to allow the laser beam at the cooling surface to be viewed through the body by a surgeon using the laser. Preferably, the transparent wall portions comprise a pair of aligned windows on opposite sides of the coolant chamber, one adjacent the mount and the other in or adjacent to the cooling surf ce. In a first embodiment, the extraction port may be connected to an aperture in the cooling surface adjacent the wall portion in the cooling surface through which the laser light impinges on the patient's skin, but, alternatively, a flexible skirt may be provided around the cooling surface to form an extraction chamber of variable volume and to which the extraction port, together with an air inlet port, may be connected for debris removal. During treatment, the cooling head is pushed onto the skin so that the cooling surface is in contact with the skin and thereby cools the skin. The head is lifted off at times during treatment and at the end of treatment, when the skirt provides some sealing to help with debris removal. The skirt may be very compliant neoprene . The laser light transparent wall portion in the cooling surface may also be optically transparent in the visible spectrum to provide for viewing of the skin surface 4 by the surgeon or else a separate transparent window may be provided. A further visible light transparent window is preferably disposed in an angled side wall of the body facing towards the aperture in the cooling surface. One or more of the transparent windows may be in the form of a lens to magnify the treatment area. At least the cooling surface of the body may be formed of metal in order to enable the surface to be efficiently cooled by the flow of coolant through coolant chamber in the body so as to provide cooling to the patient's skin by the application of the cooled surface to the skin. Using a metal body enables a relatively large mass of cold material to be provided as, in effect, a store of refrigerated material, ensuring that cooling around the treatment area can be maintained with a high degree of certainty. A C0 2 laser would be incapable of use with the prior art systems mentioned above and therefore the present invention enables the direct application of C0 2 or YAG laser energy to the skin, whilst ensuring that both satisfactory cooling and required visibility for the surgeon are maintained. Preferably the mount comprises an annular counter-bore at the open end of the bore and has fastenings for securing a laser head in a defined position within the counter-bore. The surface applied to the patient's skin may be substantially flat or significantly curved, depending on the precise application, ie the particular area of the skin to be treated. For example, when treating significantly concave areas of the skin, such as adjacent the nose, a convex surface in necessary in order that as much of the 5 surface as possible can engage the skin to provide an effective seal with the skin. Preferably, the coolant passage comprises inlet and outlet ports and an internal chamber formed within the body and opening to the patient's skin through the surface. The coolant may be a low temperature gas such as nitrogen which may be removed through the extraction port together with debris, by a suitable vacuum pump or the like. A light may be provided within the chamber to illuminate the treatment area. One examples of a cooling head according to the present invention will now be described with reference to the accompanying drawings in which : Figure 1 is an exploded view; and Figures 2A-D show the assembled head in a number of views from different positions. The cooling head 1 shown in the drawings comprises a generally box-like die-cast or injection moulded body 2 having an annular mounting lip 3 on its top, at the other end a cooling surface 4, and sidewalls 21-24, with a pair of apertures 6 formed in the end face 4, into which a pair of windows 60,61 are provided. A first window 60 is transparent to C0 2 or Erbium YAG laser light to allow a laser beam to be passed therethrough and a second window 61 is transparent in the visible light range. Within the body 2 is a chamber 5 which extends from the mount 3 connecting with it through a bore or passage 7. The annular lip 3 provides for accurate and secure location of the lower end of a laser housing 12, three locking screws 70 serving to locate the lower end of the tubular housing 12 for the laser within the bore or passage 7. A further window 120, which is transparent to C0 2 or 6 Erbium YAG laser light, allows the laser beam to be passed therethrough to the window 60 and hence to the patient's skin. A pair of tubular coolant ports 8,9 are fixed to the sidewalls 21,23 respectively at corresponding apertures 81,91 to provide for the outflow and inflow respectively of coolant from and to the chamber 5. An inclined bore sidewall 25 has a circular aperture 10 into the chamber 5, which thus provides for a viewing window. Within the aperture 10 is fitted a lens 100, held in place by a circlip 101 and sealed to the side of the aperture with an O-ring synthetic rubber seal 102. The aperture 10 is directed towards the aperture 6 which contains the window 61 to enable the surgeon to view, with slight magnification, the area of skin being treated whilst treatment is actually taking place. A neoprene rubber skirt 40 is provided around the cooling surface 4 and has inlets 41 and an outlet 42 through which air or another suitable fluid are drawn by a pump such as a vacuum pump, in order to remove debris from the patient's skin during treatment, the surgeon lifting the cooling surface 4 from the skin temporarily, allowing the fluid to entrain the debris for removal. In use, the body is pre-cooled my means of the flow of refrigerant through the chamber 5, whilst attached to the laser head housing 12, and is then applied to the skin of the patient, the flexible skirt 40 allowing the cooling surface 4 to engage the skin, to cool the area of treatment, debris from the skin being removed through the outlet port 42. Coolant is provided to the chamber through the port 9 and spent coolant, which may be filtered and re- 7 cooled for re-circulation through the chamber 5, is removed from the port 8. To increase visibility of the treatment area, a light 50 can be provided inside the chamber 5, by means of a suitable LED 51 mounted on a tube 52 extending into the chamber through an aperture 53 in the sidewall 23. The head may be anatomically shaped to suit particular areas. The contact head may be articulated to allow the head to move smoothly over anatomical obstacles and contours (eg from cheek to nose) more easily whilst maintaining intimate skin contact. The head may be arranged to rotate, for example, between specific indexed orientations, to enable the direction of traverse to be changed without having to rotate the whole body. Furthermore, the contact head may be made as a disposable component.

Claims: 8 CLAIMS 1. A cooling head for a skin treatment laser, the cooling head comprising a body having a mount at one end for attachment to a laser head to secure the body relative to the head in a fixed position; a cooling surface at the other end for application to a patient's skin; a coolant chamber disposed between the mount and the cooling surface, the chamber having wall portions transparent to C0 2 , Erbium YAG or other non-visible laser light to allow a laser beam to be passed from the mount to the patient's skin through the cooling surface, and a coolant inlet and outlet provided in the body to enable the supply of coolant to and the removal of coolant from the body in use in order to cool the cooling surface; an extraction port for enabling removal of debris from the treatment area and for connection to a vacuum source; and a window in the body optically transparent in the visible light range to allow the laser beam at the cooling surface to be viewed through the body by a surgeon using the laser. 2. A cooling head according to claim 1, wherein the transparent wall portions comprise a pair of aligned windows on opposite sides of the coolant chamber, one 9 adjacent the mount and the other in or adjacent to the cooling surface. 3. A cooling head according to claim 1 or claim 2, wherein the extraction port is connected to an aperture in the cooling surface adjacent the wall portion in the cooling surface through which the laser light impinges on the patient's skin. 4. A cooling head according to claim 1 or claim 2, wherein, a flexible skirt is provided around the cooling surface to form an extraction chamber of variable volume and to which the extraction port, together with an air inlet port, may be connected for debris removal. 5. A cooling head according to any of claims 1 to 4, wherein the laser light transparent wall portion in the cooling surface is optically transparent in the visible spectrum to provide for viewing of the skin surface by the surgeon. 6. A cooling head according to any of claims 1 to 4, wherein a separate transparent window may be provided in the cooling surface to provide for viewing of the skin surface by the surgeon. 7. A cooling head according to any of claims 1 to 6 , wherein a visible light transparent window is disposed in an angled side wall of the body facing towards the aperture in the cooling surface. 10 8. A cooling head according to any of claims 5 to 7 , wherein one or more of the transparent windows is in the form of a lens to magnify the treatment area. 9. A cooling head according to any of claims 1 to 8, wherein at least the cooling surface of the body is formed of metal in order to enable the surface to be efficiently cooled by the flow of coolant through coolant chamber in the body so as to provide cooling to the patient's skin by the application of the cooled surface to the skin. 10. A cooling head according to any of claims 1 to 9 , wherein the mount comprises an annular counter-bore at the open end of the bore and has fastenings for securing a laser head in a defined position within the counter-bore. 11. A cooling head according to any of claims 1 to 10, wherein the coolant passage comprises inlet and outlet ports and an internal chamber formed within the body and opening to the patient's skin through the surface. 12. A cooling head according to any of claims 1 to 11, further including a light within the chamber to illuminate the treatment area.

Inventors: MCMAHON RICHARD ANTHONY, WHITCROFT IAN ANDREW, MCMAHON, RICHARD, ANTHONY, WHITCROFT, IAN, ANDREW
Applicants: MCMAHON RICHARD ANTHONY, WHITCROFT IAN ANDREW, MCMAHON, RICHARD, ANTHONY, WHITCROFT, IAN, ANDREW
Application year: 1999
Main classification: A61N5
IPC codes: A61B18, A61N5