Abstract:
A cryosurgical device, with a control for the supply and/or removal of a coolant gas to a cryoprobe via a return flow or a supply flow. The device has at least one socket for the attachment of a rigid cryoprobe and a flexible cryoprobe. The socket and the plugs of the cryoprobes each form probe couplings. The configuration of the cryosurgical device allows both rigid and flexible cryoprobes to be automatically connected to the appropriate return flow conduit, independently of the level of knowledge of operating personnel.

Description:
FIELD OF THE INVENTION 
       [0001]    The invention relates to a cryosurgical device with a probe coupling formed from a socket and a plug of cryoprobes and, more specifically, to a cryosurgical device with a control for the supply and/or removal of coolant gas. 
       BACKGROUND OF THE INVENTION 
       [0002]    Cryosurgical devices are used in surgery wherever they are of a particular advantage or where high-frequency surgery or other methods cannot be used. For example, due to their unfavourable distribution, it is not really feasible to cut tumors out of the liver. Instead, in such cases, pathologically degenerated tissue is killed by means of deep freezing and then left in the body. Also, with the availability of flexible probes, foreign bodies may be extracted from body cavities by freezing them solid onto the cryoprobe. For example, peanut kernels which have been swallowed and then inadvertently inhaled must be removed from the respiratory tract. It is not possible to use mechanical gripping methods because the risk of crumbling the peanut kernels is too high. 
         [0003]    There are various methods which may be used for deep-freezing during surgery. One of these is based on the Joule-Thomson effect, wherein the atoms or molecules of a gas expanding below the inversion temperature work against the mutual attraction so that the gas loses internal energy, and therefore cools down. This effect is used with a variety of cryosurgical methods. The expanding gas—hereinafter called working gas—is usually CO 2  or N 2 O (which is also known as laughing gas in anaesthesia) because these gases are widely used in medicine for various reasons. They are neither flammable nor toxic, they have a high Joule-Thomson coefficient (μ) and they are liquefiable at normal temperature, allowing a gaseous phase to be held under constant pressure above the liquid phase in the pressure cylinder. 
         [0004]    Cryosurgical devices of the above-described kind have a reservoir, which holds a sufficient amount of working gas, probes, which are applied on the area in the body to be treated, and conduits, which pass through the probes and discharge the working gas into the inner lumen of the probes where it expands and, as a result, cools the tips of the probes. The probes are preferably made of a thermally conductive material, thereby ensuring the dissipation of the tissue heat via the probes and hence, a cooling effect. 
         [0005]    When the tissue or possible foreign body that is to be deep-frozen has cooled to a sufficiently low temperature, thawing should start at a specified time. However, it is desired that this should not require any further devices on the device to make the thawing possible. It is advantageous to simply reverse the Joule-Thomson effect, meaning the gas is compressed below the inversion temperature. For this, the probes have to be connected to a deaerator which in turn has a valve. The probe must be able to withstand a pressure that occurs in the event of valve failure if the probe continues to be filled with gas. For this, the probe must have a pressure-resistant design. Therefore, only rigid probes can be considered for this valve design. To ensure safety in non-rigid (e.g., flexible) probes, the gas passage is preferably provisionally diverted with external hoses around the return flow valve and in this way the working gas supplied to the gas disposal. Malfunctions of the device can occur if the external connection for this procedure is not fully closed. If, in this regard, the working gas is simply discharged into the ambient air of the operating theatre. If this occurs, it is easily possible, in particular in the case of laughing gas, for the maximum allowable workplace concentration (MAC) of 100 ppm to be exceeded. 
         [0006]    It is an object of the present invention to develop a cryosurgical device of the above described type that does not have the described drawbacks and can be safely operated regardless of the level of knowledge of the operating personnel. 
       SUMMARY 
       [0007]    In particular, the object of the present invention may be achieved by a cryosurgical device with a control for the supply and/or removal of a coolant gas to a cryoprobe via a return flow or a supply flow and with at least one socket for the attachment of at least a first cryoprobe and a second cryoprobe, which requires a different backflow pressure in its return flow conduit than the first cryoprobe, wherein the plugs on the cryoprobes and the socket form a probe coupling in which the socket comprises at least two return flow conduits and/or supply flow conduits and the first cryoprobe has a plug which differs from the plug of the second cryoprobe in that the removal and/or supply of the coolant gas from/to the second cryoprobe on insertion into the socket takes place via different return flow conduits and/or supply flow conduits than the removal or supply of the coolant gas from/to the first cryoprobe on insertion into this socket. 
         [0008]    By using the invention, different cryoprobes, be they rigid or flexible, can be simply and reliably connected to the same cryosurgical device, independent of the level of knowledge of the operating personnel, while ensuring safety of operation. In this regard, the coupling geometry itself ensures the correct return flow for rigid cryoprobes (via a conduit with a valve) and for flexible cryoprobes (via a conduit without a valve) in the gas disposal device. 
         [0009]    In a first embodiment of the invention, the supply flow conduits and return flow conduits belonging to the probe coupling are connected by the socket directly to a gas disposal device of the cryosurgical device. This means that, when using flexible probes, the operating personnel no longer have to provisionally divert the return flow for the gas disposal of the cryosurgical device externally around the return flow valve with hoses which are generally not intended for this purpose and hence the possible malfunctions due to the “non-closure” of the connection and the possible exceeding of workplace concentrations of the coolant gas are avoided. 
         [0010]    In addition, the insertable plug-in regions of the cryoprobe plug have a round cross section and grooves surrounding the plug-in region at each of the openings of the supply flow conduit and return flow conduit. The grooves do not have to be made separately for this. The distance between the seals results in the formation of annular chambers which are suitable to serve as gas channels. This enables the plugs to be plugged into the socket in a simple way by the operating personnel, wherein the supply flow and the return flow of the coolant gas to the corresponding cryoprobes is ensured in any possible position of the inserted plug-in region and the possibility of errors due to faulty insertion is avoided. 
         [0011]    In addition, the grooves of the return flow conduit and of the supply flow conduit of the respective plug-in region and of a corresponding socket region of the socket are separated from each other in a gas-tight way by seals, in particular by O-rings in order to ensure the corresponding connection between the return flows and supply flows between the socket and plug-in region, wherein the supply flow conduit of the first cryoprobe and the second cryoprobe is arranged at the same position on the plug and on the socket so that for the rigid and flexible probe, the supply flow of the coolant gas through the supply flow conduit from the reservoir of the cryosurgical device via the socket region into the supply flow of the corresponding plug-in region is ensured. In addition, the return flow conduit of a first rigid cryoprobe via a conduit with a valve and the return flow conduit of a second flexible cryoprobe via a conduit without a valve lead to the gas disposal device of the cryosurgical device. This means that the rigid cryoprobe can be heated using the reverse Joule-Thomson effect, wherein the gas is compressed below the inversion temperature by the valve disposed in the conduit and the coolant gas in the flexible probe can be led off without compression through a valve, and hence without the risk of an accident due to an unforeseen pressure build-up, into the gas disposal device of the cryosurgical device. 
         [0012]    It is also possible for the plug-in region in the socket of the cryosurgical device to have a fixable design. This ensures that the plug is not pushed out of the socket by any possible pressure from the supply and return flow of coolant gas or that the coolant gas in the supply flow and/or return flow does not enter a non-intended supply flow and/or return flow. Hereby, the seal can be implemented, for example, by an external thread on the socket and a correspondingly attached nut at the plug-in region, by a detachable click seal, by a detent corresponding to a detachable seal, or by a magnet attached at the lower end of the plug-in region and/or metal plate or magnet attached in the lower socket region. A deaeration opening in the rear part of the socket makes plugging in easier because the insertion is unable to form an air cushion. Furthermore, this ensures that no axial forces from pressure push the plug out again. In this case, there is no need to fix the plug. 
         [0013]    In another embodiment of the invention, the plug-in region of the first and second cryoprobe can be formed by a separate adapter, wherein the first and second plug-in regions are adapted to a first or second conventional cryoprobe. This ensures that older models of various cryoprobes can also be used with the cryosurgical device of the present invention. In addition, the socket region can also be formed by a separate adapter, wherein the separate adapter is connected via conduits to the control of the cryosurgical device and/or the reservoir for coolant gas and/or the valve and/or the gas disposal device for the return flow of coolant gas. This means that older models of the cryosurgical device can also be used for the insertion of the cryoprobes of the present invention and/or for the insertion of older cryoprobes with corresponding adapters. 
         [0014]    A further embodiment of the invention provides that the probe coupling is contained in a cryosurgical device with a device for controlling ice-ball formation, wherein the ice-ball formation is controlled by an electromagnetic field surrounding the ice ball. This enables rigid and flexible probes with electrical regions for the generation of the electromagnetic field to be simply and reliably plugged into the corresponding cryosurgical device. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]    In the following, the invention will now be described in more detail with reference to an exemplary embodiment, which will be explained in more detail with reference to the enclosed drawings. 
           [0016]      FIG. 1  illustrates a perspective view of a cryosurgical device with a rigid probe and a flexible probe. 
           [0017]      FIG. 2   a  illustrates a perspective view of a plug-in region of a rigid cryoprobe. 
           [0018]      FIG. 2   b  illustrates a sectional view along the line A-B in  FIG. 1  of a plug-in region plugged into a socket. 
           [0019]      FIG. 3   a  illustrates a perspective view of a plug-in region of a flexible cryoprobe. 
           [0020]      FIG. 3   b  illustrates a sectional view along the line A-B in  FIG. 1  of a plug-in region plugged into a socket of a flexible cryoprobe. 
           [0021]      FIG. 4   a  illustrates a perspective view of an adapter for the plug-in region of a conventional rigid probe. 
           [0022]      FIG. 4   b  illustrates a sectional view of an adapter for the plug-in region of a conventional rigid probe with an inserted plug. 
           [0023]      FIG. 5   a  illustrates a perspective view of an adapter for the plug-in region of a conventional flexible probe. 
           [0024]      FIG. 5   b  illustrates a sectional view of an adapter for the plug-in region of a conventional flexible probe with an inserted plug. 
           [0025]      FIG. 6   a  illustrates a perspective view of an adapter for the socket region of a conventional cryosurgical device with a coupling for a return flow conduit surrounding the valve for the gas disposal. 
           [0026]      FIG. 6   b  illustrates a sectional view of an adapter for the socket region of a conventional cryosurgical device with an inserted rigid probe. 
           [0027]      FIG. 6   c  illustrates a perspective view of an adapter for the socket region of a conventional cryosurgical device with an inserted flexible probe. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0028]    In the following description, the same reference numbers are used for identical parts and parts with an identical function. 
         [0029]    The exemplary embodiment in  FIG. 1  shows a cryosurgical device with a control  30 , a reservoir  40 , a container for the gas disposal  41 , a rigid first probe  10  and a flexible second probe  20 . The control  30  of the cryosurgical device comprises a socket  300  for the attachment of the rigid first probe  10  or for the attachment of the flexible second probe  20 , wherein a plug  100  of the rigid first cryoprobe  10  or a plug  200  of the flexible second cryoprobe  20  and the socket  300  of the cryosurgical device form a probe coupling. The reservoir  40  of the cryosurgical device is filled with a coolant gas for cooling the corresponding cryoprobe  10 ,  20  and is connected via conduits to the control  30  and a supply flow conduit  304  (see  FIG. 2   b ) of the socket  300 . The gas disposal device  41  is connected to a respective return flow conduit  103 ,  202  (see  FIGS. 2   b ,  3   b ) of the cryoprobes  10 ,  20  via both return flow conduits  302 ,  303  of the socket  300 , once with a valve  305  and once without a valve. 
         [0030]      FIG. 2   a  shows a perspective view of the plug  200  of the flexible second cryoprobe  20 . A plug-in region  201  has two circular openings  202 ,  203 , wherein the opening  202  is arranged at the upper end of the plug-in region  201  and the opening  203  is arranged at the lower end of the plug-in region  201 . At the respective height of the openings  202 ,  203 , there is a groove  209 ,  210  surrounding the plug-in region  201  with a width at least that of the respective opening  202 ,  203 . Arranged on both sides of the respective openings  202 ,  203  and grooves  209 ,  210  are circumferential seals  204 ,  205 ,  206 ,  207  corresponding to the plug-in region  201  in such a way that, in the inserted condition of the plug  200 , they ensure a gas-tight separation between the supply flow conduit  304 ,  203  and the return flow conduit  302 ,  202 . In the plug  200  shown in  FIG. 2   a , at the lower end of the plug-in region  201 , there is a fixing  208  which is detachable by a detent and which on insertion snaps into the notches  306  arranged correspondingly in the socket region  201 . 
         [0031]    The structure of the present probe coupling and the action between the plug  200  and the socket  300  of the cryosurgical device will be explained in more detail with reference to the sectional drawing of the plug-in region  201  inserted in a socket region  301  shown in  FIG. 2   b.    
         [0032]    In the control  30  of the cryosurgical device, the supply flow conduit  304  and the two return flow conduits  302 ,  303  lead to the socket region  301  of the socket  300 , wherein in the exemplary embodiment in  FIG. 2   b  the return flow conduit  302  of the socket  300  without a valve is connected to the return flow conduit  202  of the flexible second cryoprobe  20  and the supply flow conduit  304  is connected to the supply flow conduit  203  of the flexible second cryoprobe  20 . This ensures that the coolant gas is diverted by a valve from the flexible second cryoprobe  20  into the gas disposal device  41  without any corresponding pressure build-up and hence any potential damage to the flexible second cryoprobe  20  is avoided. When the plug  200  of the flexible second cryoprobe  20  is inserted in the socket  300  of the cryosurgical device, the fixing  208  latches into the corresponding notches  306  of the socket  300  and hence ensures that the plug  200  is held reliably in the socket  300 . By the insertion of the plug  200 , the supply flow conduit  304  of the control  30  is automatically connected via the socket  304  to the supply flow conduit  203  of the flexible second cryoprobe  20 . In addition, the return flow conduit  302  of the control  30  leading to the gas disposal device  41  is connected to the return flow conduit  202  of the flexible second cryoprobe  20 , wherein the return flow conduit  302  of the control  30  leads past the valve  305  and hence directly into the gas disposal device  41 . The grooves  209 ,  210  surrounding the openings  202 ,  203  ensure that the supply and return flow of the coolant gas is ensured in every possible position of the inserted plug  200 . 
         [0033]      FIG. 3   a  is a perspective view of a plug  100  of a rigid first cryoprobe  10 . A plug-in region  101  has two circular openings  102 ,  103 , wherein the opening  103  in the middle region of the plug-in region  101  is arranged between seals  105  and  106  and an opening  102  at the lower end of the plug-in region  101  is arranged between the seals  106  and  107 . At the respective height of openings  103 ,  102 , there is a groove  109 ,  110  surrounding the plug-in region  101  with a width at least that of the respective opening  103 ,  102 . The seals  104 ,  105 ,  106  and  107  are arranged so that in the inserted condition of the plug  100 , they ensure a gas-tight separation between the supply flow conduit  304 ,  102  and the return flow conduit  303 ,  103 . In the plug  100  shown in  FIG. 3   a , at the lower end of the plug-in region  101 , there is a fixing  108  which is detachable by a detent and which on insertion snaps into the notches  306  correspondingly arranged on the socket region  301 . 
         [0034]    There now follows a more detailed explanation of the structure of the present probe coupling and the interaction between the plug  100  and the socket  300  of the cryosurgical device with reference to the sectional drawing of the plug-in region  101  inserted in the socket region  301  in  FIG. 3   b.    
         [0035]    In the control  30  of the cryosurgical device, a supply flow conduit  304  and the two return flow conduits  302 ,  303  lead to the socket region  301  of the socket  300 , wherein, in the exemplary embodiment in  FIG. 3   b , the return flow conduit  303  of the socket  300  with a valve  305  is connected to the return flow conduit  103  of the rigid first cryoprobe  10  and the supply flow conduit  304  is connected to the supply flow conduit  102  of the rigid first cryoprobe  10 . Due to this, on the discharge of the coolant gas through the valve  305  in the gas disposal device  41 , the coolant gas is compressed below the inversion temperature and the rigid first cryoprobe thaws more quickly due to the reversal of the Joule-Thomson effect. When the plug  100  of the rigid first cryoprobe  10  is inserted in the socket  300  of the cryosurgical device, the fixing  108  latches in the corresponding notches  306  of the socket  300  and hence ensures that the plug  100  is held reliably in the socket  300 . When the plug  100  is inserted, the supply flow conduit  304  of the control  30  is automatically connected via the socket  304  to the supply flow conduit  102  of the rigid first cryoprobe  10  and the return flow conduit  303  of the control  30  leading to the gas disposal device  41  is automatically connected to the return flow conduit  103  of the rigid first cryoprobe  10 , wherein the return flow conduit  303  of the control  30  leads through the valve  305  into the gas disposal device  41 . The grooves  109 ,  110  surrounding the openings  103 ,  102  ensure that the supply and return flow of the coolant gas is ensured in every possible position of the inserted plug  100 . 
         [0036]    The fixing of the plug  100 ,  200  in the socket  300  can also be implemented by other fixings suitable for the plugs  100 ,  200  of the cryoprobes  10 ,  20 . The plug  100 ,  200  can, for example, also be attached by an external thread attached to the outside of the socket  300  and a nut attached movably to the upper plug-in region and corresponding to the external thread in the socket  300 . In addition, the fixing of the plug  100 ,  200  in the socket  300  can also be achieved by a click seal or by a magnet attached at the lower end of the plug-in region  101  and/or a metal plate attached at the lower socket region  101 . Furthermore, this should also include possible fixings for a plug  100  in a socket  300  known or evident to the person skilled in the art. 
         [0037]    A further exemplary embodiment of a probe coupling is shown in  FIGS. 4   a ,  4   b ,  5   a , and  5   b . This involves two adapters  50 ,  60  for the plugs of rigid and flexible cryoprobes in older models which are not suitable for use with the cryosurgical device. The adapter comprises a plug-in region  501 ,  601  suitable for use in the cryosurgical device and a socket  520 ,  620  compatible with the respective plug of the conventional models. Each plug-in region  501 ,  601  of the adapter  50 ,  60  comprises two openings for the supply and return flow conduits  502 ,  503 ,  602 ,  603  and comprises grooves  509 ,  510 ,  609 ,  610  surrounding the plug-in region at the respective height of the openings  502 ,  503 ,  602 ,  603 . In addition, the openings  502 ,  503 ,  602 ,  603  and the grooves  509 ,  510 ,  609 ,  610  are separated from each other in a gas-tight way by seals  504  to  506  and  604  to  607 , in particular O-rings, in the inserted condition. At the lower end of the plug-in region  501 ,  601  of the adapter  50 ,  60 , there is, for example, a detent  508 ,  608  suitable for fixing the adapter  50 ,  60  in the socket region  301  of the cryosurgical device. The openings of the supply and return flow conduits  502 ,  503 ,  602 ,  603  of the adapter  50 ,  60  are arranged so that on insertion in the socket  300  of the cryosurgical device of the present invention, they are each connected to the supply flow conduit  304  and return flow conduit  302 ,  303  suitable for the corresponding flexible or rigid cryoprobe  10 ,  20 . In this regard, the supply flow conduit of the conventional rigid cryoprobe is connected via the adapter  50  to the supply flow conduit  304  of the control of the cryosurgical device and the return flow conduit of the conventional rigid cryoprobe is connected via the adapter  50  to the return flow conduit  303  with a valve  305  of the control of the cryosurgical device. On insertion in the socket  300  of the cryosurgical device of the present invention, the supply flow conduit of a conventional flexible cryoprobe is connected via the adapter  60  to the supply flow conduit  304  and the return flow conduit of the conventional flexible cryoprobe is connected via the adapter  60  to the return flow conduit  302  bypassing the valve  305 . 
         [0038]    In another exemplary embodiment of a probe coupling,  FIGS. 6   a ,  6   b  and  6   c  show an adapter  70  suitable for the attachment of the flexible and rigid cryoprobes  10 , of the invention for older models of a cryosurgical device. The adapter comprises a socket  701 , a plug  703  attached thereto for attachment to a conventional cryosurgical device and a connecting pipe  702  protruding out of the lower outer part of the socket. An internal socket region  708  comprises three openings of conduits  709 ,  710 , and  711  which are arranged so that on the insertion of flexible cryoprobe  20  of a cryosurgical device of the present invention, the supply flow conduit  203  of the flexible cryoprobe  20  is connected via the supply flow conduit  710  of the adapter  70  to the supply flow conduit of the conventional cryosurgical device and the return flow conduit of the flexible cryoprobe  20  is connected via the return flow conduit  711  of the adapter  70  and via an external conduit (not shown in  FIGS. 6   a ,  6   b ,  6   c ) without a valve to the gas disposal device of the conventional cryosurgical device and that, on the insertion of rigid cryoprobe  10  of a cryosurgical device of the present invention, the supply flow conduit  102  of the rigid cryoprobe  10  is connected via the supply flow conduit  710  of the adapter  70  to the supply flow conduit of the conventional cryosurgical device and the return flow conduit  103  of the rigid cryoprobe  10  is connected via the return flow conduit  709  of the adapter  70  to the return flow conduit of the cryosurgical device containing a valve. In addition, the openings of the conduits  709 ,  710 ,  711  are separated from each other in a gas-tight way by seals  704  to  707 , in particular O-rings, in the inserted condition. 
         [0039]    In a further exemplary embodiment, the adapters  50 ,  60 ,  70  can also be used for a connection between a conventional cryosurgical device and a conventional rigid or flexible cryoprobe. In this regard, the adapter  70  is inserted in the socket of the conventional cryosurgical device and the adapters  50 ,  60  placed on the respective plugs of the conventional flexible and/or rigid cryoprobes, which means the suitable connection between the supply flow- and return flow conduits of the flexible and/or rigid cryoprobe is ensured in each case. 
         [0040]    The probe coupling can also be installed internally on a cryosurgical device comprising a device for controlling the ice-ball formation by means of correspondingly generated electromagnetic fields or achieved by corresponding adapters on the cryosurgical device or on the plugs of the cryoprobes. Also possible are combinations of plugs with contacts to temperature sensors or electrical thawing aids. 
         [0041]    At this point, reference is made to the fact that all the parts described above are claimed as inventive in their own right and in any combination, in particular the details shown in the drawings. The person skilled in the art is familiar with modifications.