Patent Publication Number: US-2011060328-A1

Title: Portable therapy delivery device with fluid delivery

Description:
This application is a continuation of common-owned, co-pending U.S. application Ser. No. 11/414,503 filed on Apr. 28, 2006, and claiming priority to U.S. Provisional Application Ser. No. 60/682,936, filed May 20, 2005, the entire contents of which are incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The invention relates to medical devices and, more particularly, to devices for controlling therapy delivery. 
     BACKGROUND 
     While some patients must undergo major surgery to treat a diagnosed problem, other therapies may be performed quickly and at a variety of locations. Some of these therapies may include tissue ablation, tissue removal, cauterization, ultrasound therapy, and implantable device programming. Performing some therapies without an operating room enables more patient treatments at a lower cost. These outpatient routines are becoming increasingly popular with both physicians and patients. 
     Since outpatient procedures are commonly performed in small clinics with limited space for large therapy systems, portable therapy devices allow small clinics to treat patients with a limited number of operating or procedure rooms. Alternatively, some portable devices are moved to the patient&#39;s room and the procedure is performed in that room. These portable devices may have wheels to roll the device between rooms or be light enough for a user to carry between locations. Each procedure may be performed by a physician and may require one or more assistants. 
     One example of an outpatient therapy is treatment for benign prostatic hyperplasia (BPH). BPH is a condition caused by the second period of continued prostate gland growth. This growth begins after a man is approximately 25 years old and may begin to cause health problems after 40 years of age. The prostate growth eventually begins to constrict the urethra and may cause problems with urination and bladder functionality. While invasive surgery can remove the enlarged prostate, minimally invasive surgery has recently become an effective alternative. This therapy introduces a catheter and needle into the urethra and to the prostate. The needle is entered into the prostate where it heats and destroys a portion of the surrounding prostate tissue. In this example, the patient may enjoy effective therapy without any major side effects, and the physician may perform a less invasive procedure that incorporates less risk with respect to invasive surgery. 
     SUMMARY 
     This disclosure is directed to a system that may be used to deliver a plurality of therapies through the use of one portable system. The system includes a fluid pump that pumps fluid from a container to a therapy device to treat a patient. The fluid pump resides within a pump bay of the therapy delivery device. The fluid may be used to cool a tissue of the patient or clear debris. In one embodiment, generated signals may be delivered by a peripheral accessory connected to the generator through the connector board, and the generator may generate radio frequency (RF) energy for the purpose of prostate tissue ablation, where the effective ablation area of an electrode is increased by the fluid. In addition, the therapy delivery device may include a touch screen user interface, a visual operation indicator, a signal generator, and a removable connector board. 
     Portable therapy devices are increasingly important and valuable to medical clinics because they allow patients to be treated in any area or room of the facility. This portability may lessen the cost of therapy and enable a clinic to perform a wider variety of therapies than with larger systems. In addition, treatment efficacy increases when these portable therapy devices employ simple and easy to use controls that lessen complexity, and possibly error rate, of the procedure. 
     The fluid pump residing in the portable therapy device eliminates the need for the physician to use an external pump and provides all components within one package. A processor within the therapy delivery device controls the fluid pump to deliver the correct amount of fluid to the patient as needed by the therapy or when desired by the physician. In addition, the pump may be quickly removed so that fluid pumps may be exchanged in the clinic without technical support personnel. A channel of the pump bay also protects the fluid pump and internal components from damage by keeping fluid out of the pump bay. 
     In an exemplary use of the portable therapy device, the generator may generate radio frequency (RF) energy for the purpose of prostate tissue ablation. The energy may be directed through a connected lead of an ablation device, which is attached to the connector board, to an electrode or electrodes placed at a certain location within the prostate. As described, the system may provide fluid to cool the urethra and fluid to flow from an electrode during ablation to increase the efficacy of treatment. 
     Not only would the device be capable of modification to treat other conditions, the device may be conducive for equipment upgrades as technology or treatment methods advance. For example, an endoscopic camera may be implemented at the tip of the ablation catheter to help the physician guide electrodes into place and monitor treated tissue. 
     In one embodiment, this disclosure is directed to a fluid delivery system that includes a fluid pump that moves a fluid from a first container to a therapy device, wherein the therapy device delivers the fluid to a target tissue of a patient. The system also includes pump bay of a device housing that accepts the fluid pump, a processor that controls a rate that the fluid is moved from the first container to the therapy device, and a user interface that allows a user to provide instructions to the processor. 
     In another embodiment, this disclosure provides a method for delivering a fluid that includes accepting a fluid pump within a pump bay of a device housing and delivering a fluid from a first container to a target tissue of a patient via a fluid pump and a therapy device. The method also includes controlling a fluid delivery rate between the first container and the target tissue and receiving a user input specifying a particular fluid delivery rate. 
     In an additional embodiment, this disclosure provides a fluid delivery device that includes a device housing comprising a pump bay and a fluid pump that moves a fluid from a first container to a therapy device, wherein the fluid pump is disposed within the pump bay. The device also includes a pump bay door attached to the device housing via a hinge, wherein the pump bay door encloses the fluid pump when the pump bay door is in a closed configuration, and a securing mechanism that secures the fluid pump within the pump bay. 
     Although the device described herein may be especially applicable to an RF generator device and prostate tissue ablation, alternative diagnostic and therapeutic procedures may be used in the clinic with this device. Exemplary diagnostic procedures may include general endoscopy, gastric endoscopy, ultrasound imaging, blood pressure measurements, and blood oxygenation measurements. Alternative therapies may include ultrasound treatments, cauterizing, and implanted device programming. 
     In various embodiments, the device described in this disclosure may provide one or more advantages. For example, the fluid pump is integrated into the portable therapy device and controlled by a processor of the device. No external fluid pump is needed to deliver fluid to the patient. In addition, the fluid pump may be exchanged to support the needs of the therapy. 
     In some cases, the system may have the ability to transfer data between other devices. This aspect may be useful for analyzing therapy data, monitoring patient trends, troubleshooting device problems, and downloading software upgrades. The device may also be able to transfer data to a physician&#39;s hand held computer via a USB flash memory device or wireless communications. 
     The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a conceptual diagram illustrating an example generator system in conjunction with a patient. 
         FIG. 2  is a top view of an example generator system in the screen closed configuration. 
         FIG. 3  is a side view of an example generator system in the screen closed configuration. 
         FIG. 4  is a front view of an example generator system in the screen open configuration. 
         FIG. 5  is a top view of a peristaltic fluid pump in an open pump bay of an example generator system. 
         FIG. 6  is a top view of an internal gear fluid pump in an open pump bay of an example generator system. 
         FIG. 7A  is an enlarged side view of an example light bar of an example generator system. 
         FIGS. 7B and 7C  are enlarged end views of two example light bars with slightly different shapes. 
         FIG. 8A  is an enlarged side view of an example removable connector board. 
         FIG. 8B  is a top view of an example removable connector board. 
         FIG. 9  is functional block diagram illustrating components of an exemplary generator system. 
         FIG. 10  is a flow diagram illustrating an example technique for operating the generator system in attaching a peripheral accessory and providing therapy to a patient. 
         FIG. 11  is a flow diagram illustrating an example technique for identifying a connected peripheral accessory and determining its status before providing therapy to a patient. 
         FIG. 12  is an exemplary screen shot of the main menu provided by the user interface. 
         FIG. 13  is an exemplary screen shot of the delivery screen when the system becomes operational. 
         FIG. 14  is an exemplary screen shot of the delivery screen when ablation therapy is being delivered. 
         FIG. 15  is an exemplary screen shot of the delivery screen and a temperature warning message during therapy. 
         FIG. 16  is an exemplary screen shot of the delivery screen displaying an error message when the therapy is terminated due to the return electrode malfunction. 
         FIG. 17  is an exemplary screen shot of the delivery screen when the therapy is completed. 
         FIG. 18  is an exemplary screen shot of the post session menu. 
     
    
    
     DETAILED DESCRIPTION 
     This disclosure is directed to a portable therapy delivery device, or system, to be used by a physician to treat a variety of patient conditions. The portable delivery device may provide a platform for a plurality of peripheral accessories, i.e., therapy or diagnostic devices, to be connected. A platform such as this may be useful to the medical community by offering flexibility in a device that may be used for a variety of purposes. Additionally, costs for the manufacturer, physician, and patient may be decreased by utilizing a platform device which may be slightly modified to perform a number of diagnostic or therapeutic tasks. This platform device may even be used across multiple medical disciplines. Such examples may include any type of tissue ablation (e.g. prostate, heart, liver, mouth, throat, eye, etc.), ultrasound imaging, endoscopy, implantable programming, or any combination of these and other procedures. 
     For exemplary purposes, the description provided herein is aimed at a portable therapy delivery device that includes hardware and software capable of providing RF ablation to the prostate, in this case using a wet electrode. In some cases, RF ablation may be conducted with a dry electrode. The delivery device provides an RF generator, a fluid pump, a ablation device, and a user interface to control the aspects of the therapy. A needle is introduced to the prostate via the urethra, where it delivers the RF energy to the prostate to ablate surrounding tissue. The circulation of fluid from and/or around the electrode may allow for a greater volume of tissue to be destroyed in a shorter period of time, effectively increasing therapy efficacy. This therapy may also be coupled with other associated therapies or diagnostic equipment attached to the portable therapy delivery device. For example, multiple fluid pumps may be included within the platform or added via USB port control. Additional pumps may enable tissue irrigation for clearing ablated tissue or cooling surrounding tissue. 
       FIG. 1  is a conceptual diagram illustrating an example system  10  in conjunction with a patient  12 . As shown in  FIG. 1 , system  10  may include a portable therapy delivery device (PTD)  14  that delivers therapy to treat a condition of patient  12 . In this exemplary embodiment, PTD  14  is a radio frequency (RF) generator that provides RF energy to heat tissue of the prostate gland  24 . This ablation of prostate tissue destroys a portion of the enlarged prostate caused by, for example, benign prostatic hyperplasia (BPH). The RF energy is transmitted through electrical cable  16  to ablation device  20 . The energy is then transmitted through a probe  22  and is delivered to prostate  24  by an electrode (not shown). In addition to the electrode, a fluid may be pumped out of delivery device  14 , through tube  18 , into ablation device  20 , and through probe  22  to interact with the RF energy being delivered by the electrode. This wet electrode may increase the effective heating area of the electrode and increase therapy efficacy. 
     In the illustrated example, PTD  14  includes an RF generator that includes circuitry for developing RF energy from an included rechargeable battery or a common electrical outlet. The RF energy is produced within parameters adjusted to provide appropriate prostate tissue heating. The RF current is conveyed from the PTD  14  via an electrical cable  16  which is connected to a connector board of PTD  14 . A connector board may be inserted into PTD  14  for this therapy, and it may be replaced with a different connector board for additional therapies or diagnostics. Fluid is provided to the electrode by a pump (not shown) also located within PTD  14 . The pump may also be replaceable to enable substitute pumps to be used in this or other therapies. 
     Therapy energy and other associated functions such as fluid flow are controlled via a graphic user interface located on a color liquid crystal display (LCD), or equivalent screen. The screen may provide images created by the therapy software, and the user may interact with the software by touching the screen at certain locations indicated by the user interface. In this embodiment, no additional devices, such as a keyboard or pointer device, are needed to interact with the device. The touch screen may also enable device operation. In some embodiments, the device may require an access code or biometric authorization to use the device. Requiring the physician to provide a fingerprint, for example, may limit unauthorized use of the system. 
     Connected to PTD  14  are one cable  16  and one tube  18 . Cable  16  conveys RF energy and tube  18  conducts fluid from PTD  14  to ablation device  20 . Ablation device  20  may be embodied as a hand-held device as shown in  FIG. 1 . Ablation device  20  may include a trigger to control the start and stop of therapy. The trigger may be pressure sensitive, where increased pressure of the trigger provides an increased amount of RF energy or increase the fluid flow to the tissue of prostate  24 . Attached to the distal end of ablation device  20  is a probe  22 . The probe may provide a conduit for the fluid and provide isolation between one or more needles that conduct RF energy and patient  12 . Since the probe  22  would be entering patient  12  through the urethra, the probe may be very thin in diameter and long enough to reach the prostate in any patient. 
     Probe  22  may contain one or more electrodes for delivering RF current to the tissue of enlarged prostate  24 . Probe  22  may contain one or more needles, each with an electrode, for penetrating into two opposite areas of prostate  24  from the urethra. When RF energy is being delivered, tissue may increase in temperature, which may destroy tissue. This heating may last a few seconds or a few minutes, depending on the condition of prostate  24 . In some embodiments, the fluid may exit small holes in the needles and flow around the electrodes. This conducting fluid, e.g., saline, may increase the effective heating area and decrease the heating time. Additionally, ablating tissue in this manner may enable the physician to complete therapy without repositioning the needle. 
     In some cases, ablation devices may only be used for one patient. Reuse may cause infection and contamination, so it may be desirable for the ablation device to only be used once. A feature on the ablation device may be a smart chip in communication with the PTD  14 . For example, when the ablation device is connected to PTD  14 , the PTD may request use information from the ablation device. If the device has been used before, the PTD may disable all functions of the ablation device to prevent reuse of the device. Once an ablation device has been used, the smart chip may create a use log to identify the therapy delivered and record that the device has been used. The log may include data of RF energy delivered to the patient, total RF energy delivered in terms of joules or time duration, error messages created, or any other pertinent information. 
     In some embodiments, additional peripheral accessories, i.e., therapy devices or diagnostic devices, may be available to the physician at one time. For example, the ablation device for ablating prostate tissue might be coupled with an endoscopic camera for locating the prostate and monitoring therapy. The camera images may then be transferred back to PTD  14  and presented on the screen in real-time. Other examples may include ultrasound imaging coupled with ablation therapy or programming implanted medical devices. The flexible platform of the PTD  14  may allow various diagnostic and therapy combinations to be combined into one device. 
       FIG. 2  is a top view of an example generator system in the screen closed configuration. The screen housing  26  is folded down in the closed position. Attached to screen housing  26  are hinges  36 A and  36 B and light bar  28 . Pivot  34  is attached to hinges  36 A and  36 B to the main housing of PTD  14 . A spring steel member of hinges  36 A and  36 B is employed to provide a moment arm about the axis formed by pivot  34  and the hinges. The moment arm provides a pop-up of screen housing  26  and allows the screen housing to remain in place when open. Button  30  releases screen housing  26  and resides at the bottom of handle  32 . Also visible in this top view is the pump bay door  38  and bases  40 A and  40 B at the rear of PTD  14 . When screen housing  26  is closed, PTD  14  is able to be moved while protecting all internal components. PTD  14  includes device housing  19  which encloses the components of the PTD. 
     All housing materials used in PTD  14  may be a sturdy and light material capable of providing structural support and component protection. In a preferred embodiment, the housing may be constructed of a metal such as, for example a magnesium or an aluminum alloy, but other materials may be used. These materials may include, but not be limited to, polymers such as polyurethane, or a woven polymer fabric such as those available under the trade designation Kevlar from E.I. du Pont de Nemours, Wilmington, Del. Screen housing  26  may be constructed of at least one of a magnesium alloy, an aluminum alloy, polycarbonate, polypropylene, polyurethane, polyethylene, and polystyrene. 
     In this configuration, screen housing  26  is resting flat against the main housing of PTD  14  and latched so that it cannot be opened. The screen is on the inside of the screen housing  26  in this illustration. Once the user pushes button  30 , screen housing  26  pops up to enable the user to lift screen housing  26  and rotate it up to expose the screen. Screen housing  26  rotates along a longitudinal axis created by the interaction of hinges  36 A and  36 B with pivot  34 . Hinges  36 A and  36 B may include bushings on the outer interface with the main housing to seal the main housing from any liquid ingress at the hinges. Pivot  34  may include a mechanism which creates a small moment arm on screen housing  26  when the screen housing is latched closed. When button  30  is pressed, the torque is released to move the screen housing away from the main housing of PTD  14 . Pivot  34  may also include a mechanism for providing resistance against screen housing movement, once opened. This resistance may cause a user to push against screen housing  26  to create a moment arm that forces the screen housing into position. Resistance in pivot  34  also allows the screen to be placed at any angle with respect to the main housing of PTD  14 . 
     In some embodiments, screen housing  26  may open completely after pressing button  30  by the use of a spring system or an electrical stepper motor. This lifting mechanism may also utilize a small hydraulic lift to provide enough torque to raise the screen housing. In some cases, movement may be smoothed with the use of a dampening device. A damping device may aid in a gradual start and stop to screen movement. 
     A three-sided light bar  28 , e.g. a visual operation indicator, is located at the top of screen housing  26 . While the example of  FIG. 2  depicts the light bar as a concaved curved shape, the light bar may be presented in a variety of shapes. These various shapes may include a sphere, cube, rectangular cube, trapezoid, or any other polygon or rounded three dimensional shapes. This light bar may present the user with information regarding the operation of PTD  14 . Due to the three-sided nature of the light bar, the user may view the light bar from a variety of locations around PTD  14   
     Handle  32  is positioned at the front of PTD  14  and is part of the main housing. The handle is rounded with a large hole to allow a hand of any size to carry PTD  14 . Some locations on handle  32  may include ergonomic coverings to increase friction between a hand and handle  32 . These coverings may also be soft to provide a comfortable interface when the user is carrying PTD  14 . In some embodiments, handle  32  may be rectangular instead of curved as shown in the example of  FIG. 2 . In some cases, a strap or harness may be attached to handle  32  for easier carrying. This strap may be positioned over a shoulder of the user to remove a portion of the PTD load from the hand that is attached to handle  30 . 
     At the rear of PTD  14 , pump bay door  38  allows access to a replaceable fluid pump. The pump bay door  38  may be flush with the external housing and attached by a hinge along the top edge closest to the middle of PTD  14 . The door may rotate up along the hinge axis to expose the pump. When closed, the door may stay closed due to friction or be secured by a mechanical latch. Alternatively, the hinge may provide resistance to pump bay door  38  opening. In some embodiments, pump bay door  38  may open along a different axis or slide back within the main housing to expose the fluid pump. Under the pump bay door  38 , the pump bay may include a lip along all bay edges to keep fluid from entering the pump bay during an accidental spill on PTD  14 . 
     Bases  40 A and  40 B are located at the back end of PTD  14 . These may allow the device to stand on end when not in use. Bases  40 A and  40 B may be made out of a durable material, such as hard or soft rubber or polyurethane plastic. The material of bases  40 A and  40 B may measure between a  35  and  55  on a durometer. The material may absorb any impact from collisions or falls. In other embodiments, the bases may be shaped differently or connected to provide one large footing. 
       FIG. 3  is a side view of an example generator system in the screen closed configuration. The side view illustrated in  FIG. 3 . shows screen housing  26  closed against the main housing, with recess  44  lying underneath the screen housing. Handle  32  is located at the front of PTD  14 , while pads  42 A and  42 B are located at the bottom corners of the main housing. Inset into the main housing is connector board  46 , which contains accessory port  48  and accessory port  50 . Below pump bay door  38  is indent  54 . Ventilation holes  52  are located along the side at the rear of PTD  14 , and base  40 A is attached to the rear of PTD  14 . 
     In this example, recess  44  is only accessible when screen housing  26  is open. When the screen housing is lifted up, recess  44  may be used to hold device manuals, procedural notes, or any items that may be useful to the user. In some embodiments, recess  44  may include a clip or clips that hold a manual in position. These clips may hold down a portion of the manual or slide through the spiral binding of the manual. The clips may be able to be removed in order to read the manual closer or exchange the manual with an updated version. In another embodiment, recess  44  may include a self-adhesive label highlighting the connections necessary to operate PTD  14 . This may be referred to as a quick start guide to enable the user to correctly attach the necessary components to PTD  14 . Recess  44  may be one large rectangular area in the main housing, or it may be sectioned off to contain specific tools or items. In some embodiments, recess  44  may not be included in the construction of PTD  14 . 
     Along the side is the external portion of the connector board  46 . Connector board  46  is connected to the connector board port located within PTD  14 . Board  46  may snap into place, require multiple screws to be secure, or be installed into the main housing by removing a section of the main housing. In some embodiments, connector board  46  may be constructed in different shapes or sizes. For example, the connector board may be oval or diamond shaped. In addition, multiple smaller connector boards may be utilized by PTD  14 . 
     Connector board  46  may include accessory port  48  and accessory port  50  for connecting an ablation device to the connector board. Each accessory port may include a mechanism for securely attaching the associated ablation device. These mechanisms may include screws, latches, or a snap closure. While the illustrated connector board is configured for prostate ablation, many other connector boards may be exchanged to provide another therapy, diagnostic, or combination of the two procedures. 
     In this embodiment, accessory port  48  provides the connection between ablation device  20  and PTD  14  via cable  16 . Accessory port  48  transfers the RF energy produced within PTD  14  to cable  16 , and may receive therapy information such as tissue temperature as feedback. Connector  50  may be used to connect a return ground electrode that is attached to the lower back of the patient. In other embodiments, connector board  46  may include more or less accessory ports, and the accessory ports may be of any size and shape. For example, a video device for monitoring the therapy may be connected to the connector board. 
     In this illustration, some of the components for generating RF energy, generating the user interface, and providing power to PTD  14  may be located in the rear of the housing. For this reason, ventilation holes  52  may be included in the housing to allow heat from within the housing to escape. In some embodiments, the holes may form a different pattern and they may be of different shapes and sizes. Additionally, an exhaust fan may be placed by the holes on the inside of the housing. It should be noted that ventilation holes may be included on all or any sides of PTD  14 . In particular, holes may be provides on the bottom, each side, and the rear of PTD  14 . These holes may enable a steady flow of air to remove heat generated by the electrical components within PTD  14 . 
     Indent  54  may be located just below pump bay door  38  to allow a user to open the door. The indent may allow a user to fit a finger underneath the door and pop it open. The indent  54  may instead be located at a different site along door  38 . In some embodiments, indent  54  may be a button that includes a mechanism for opening the door. Alternatively, an electrical latch may be opened by using the touch screen in the screen housing when the device is operational. 
     The bottom of PTD  14  includes four pads  42  ( 42 A and  42 B are shown) at the four corners to support the device weight while protecting the components within PTD  14  and the surface which the device is resting on. The pads may be positioned at the four corners of PTD  14  to provide stability, and they may be spherical in shape in this embodiment. Additionally, the spherical pads may include a plurality of evenly spaced smaller spheres near the contact point of the pad to increase contact surface area. Pads  42  may be constructed of a soft or hard rubber or other durable material similar to bases  40 A and  40 B. Pads  42  may be compliant and such that the pads prevent PTD  14  from slipping or sliding on a level or non-level surface in which the PTD has been placed. In addition, pads  42  may not stick to the surface they contact. Pads  42  may be attached to PTD  14  by an adhesive, screw, or other fixation device. 
     The rear of PTD  14  is not shown, but it may contain a variety of features. An exhaust fan may be mounted within the main housing of PTD  14  to expel heat from the device though ventilation holes. A power connection may also be available for connecting the power supply to a common AC 115 Volt electrical outlet via a grounded electrical cable. Connected to the power supply may be a main power switch which is used to turn the system on and off. 
     Additionally, a ground terminal may be provided to electrically ground the entire system. This redundancy may be provided as a backup to the safety system provided herein. There may also be an accessory port for a floor pedal. Some users may prefer a foot operated pedal to start and stop therapy instead of, or in addition to, the controls on the hand held ablation device. A second USB port may also be provided on the back of PTD  14 . In some embodiments, a network cable connection may be provided for further communications with a network or the internet. 
       FIG. 4  is a front view of an example generator system in the screen open configuration. Open screen housing  26  includes touch screen  64 , universal serial bus (USB) port, and audio speaker  66 . Light bar  28  is attached to the top of screen housing  26  and includes lights  56 ,  58 , and  60 . Screen housing is attached to PTD  14  by hinges  36 A and  36 B, and is opened by button  30 . Handle  32  allows a user to carry the device, and pads  42  ( 42 A and  42 C are shown) provide secure and stable resting points for the PTD. 
     Screen housing  26  may be opened to allow the physician to view touch screen  64  by pressing button  30 . Button  30  is attached to a rolling latch mechanism that the downward movement of the button into lateral movement to retract the latch from the screen housing. Once this occurs, the screen may pop up a short distance to allow the user to open the screen with one hand. The screen may be left at any opening angle with respect to the closed position, and a screen housing stop may limit the opening angle. In some cases, this angle may be approximately 100 degrees from the resting position. In some embodiments, the screen may automatically open completely once button  30  is pressed. This opening may be enabled through a spring hinge or electronic motor. 
     Some embodiments of the screen housing  26  may include greater flexibility in screen positioning. Screen housing  26  may be mounted on a rotating hinge in which, once opened, the screen may be rotated 180 degrees in either direction. This screen rotation may allow the physician to view the screen from any location around the PTD. Other embodiments may allow further flexibility, such as a detachable screen or a wireless handheld viewing device. 
     Screen housing  26  may include a variety of features. Screen  64  may be a liquid crystal display (LCD) touch screen. The physician may interact with screen  64  by using a finger or stylus to touch the screen where certain icons appear. In this manner, the physician may control the therapy and PTD operation without the use of additional keyboards or pointer devices. Screen  64  may utilize any type of touch screen technology that allows the physician to select icons or graphics on the screen with a finger, stylus, or latex gloved finger. 
     Screen  64  may utilize a resistive system to detect the location of a touch on the screen. The resistive system consists of a normal glass panel that is covered with a conductive and a resistive metallic layer. The conductive and resistive layers are separated by spacers with a scratch-resistant layer disposed on the surface of screen  64 . An electrical current flows through the conductive and resistive layers when screen  64  is operational. When the physician touches the screen, the conductive layer contacts the resistive layer on the location of the touch. The change in the electrical field is detected by screen  64  and the coordinates of the location is calculated by a processor. Once the coordinates are calculated, a driver translates the location into data that the operating system uses to control system  14 . 
     In some embodiments of screen  64 , screen  64  may utilize a capacitive system. The capacitive system includes a capacitive layer that stores electrical charge that is placed on a glass panel of screen  64 . When the physician touches the monitor with a finger, a portion of the electrical charge is transferred to the physician. This transfer of electrical charge reduces the charge in the capacitive layer. A plurality of circuits located at each corner of screen  64  measures the decrease in charge, and a processor calculates the location of the touch from the relative differences in electrical charge at each corner of the screen. Screen  64  may be brighter when using the capacitive system as compared to the resistive system, but insulating objects may not be detected by the screen. 
     In alternative embodiments, screen  64  utilizes a surface acoustic wave system to detect touch on the screen. Two transducers, one receiving transducer and one sending transducer, are placed along an x axis and a y axis of the glass plate of screen  64 . A plurality of reflectors are also placed on the glass plate to reflect an electrical signal sent from one transducer to the other transducer. The receiving transducer detects any disturbance in the sending wave from a touch to screen  64  and determines the location of the disturbance. The surface acoustic wave system contains no metallic layers, which allows almost all light to be delivered from screen  64  to the physician. 
     Adjacent to screen  64  is speaker  66 . Speaker  66  may deliver audible tones or voice cues related to PTD operation or therapy progress. The volume of speaker  66  may be adjusted by touch screen  64  or a small dial on the side of screen housing  26 . On one side of screen housing  26 , a USB port  62  may be included for the transfer of data between PTD  14  and another computing device. In the preferred embodiment, USB port  62  may be located on the side of PTD  14  opposite to connector board  46  to keep USB port  62  separate from therapy connections. In some embodiments, a video camera may be located within screen housing  26 . 
     In other embodiments, screen housing  26  may include other communication devices different than a USB port  62 . For example, screen housing  26  may include an IEEE 1394 port, a serial port, a video output, a video input, a microphone, or an audio output. Alternatively, screen housing may contain a wireless communication antenna. The antenna may be completely inside screen housing  26  or protruding outside of the screen housing. The wireless communication antenna may provide communication via protocols such as 802.11 a, 802.11 b, 802.11 g, or Bluetooth. Other protocols may include the medical implant communication system (MICS) or the medical implant telemetry system (MITS) that operate at a frequency between  402  and  405  megahertz. 
     Light bar  28  is located at the top of screen housing  26 . The light source within light bar  28  may be one or more colored lights. These lights may include electric light bulbs, light emitting diodes (LEDs), light pipes, or any other device that emits visible light. Any number of light sources may be used, and they may each emit one or more wavelength of light, or color. In one embodiment, three LEDs may be used beneath the translucent light bar covering. Power light  56  may be green in color and illuminate when PTD  14  power is on. Therapy lights  58  and  60  may be blue in color and illuminate when therapy is being delivered. These light sources cause light bar  28  to glow when they are illuminated. Lights may continue to illuminate when screen housing  26  is closed. 
     In some embodiments, the light sources may blink at certain times. For example, therapy lights  58  and  60  may begin to blink when therapy is ready to be delivered. In some cases, the lights may be able to change color to indicate therapy progress or warn the physician of a problem. For example, lights  58  and  60  may begin to flash red in color if a device becomes disconnected or the therapy reaches unsafe levels for the patient. 
       FIG. 5  is a top view of a peristaltic fluid pump in an open pump bay of an example generator system. As shown in  FIG. 5 , PTD  39  is an alternative embodiment of PTD  14 . The partial view of PTD  39  includes opened pump bay door  38  attached to device housing  19  via hinges  41 A and  41 B. Pump bay  29  also includes channel  37  around the upper edge of the pump bay. Fluid pump  43  is disposed within pump bay  29  and attached to the pump bay via securing mechanisms  57 A and  57 B. Fluid pump  43  includes rotor  45 , tube channel  47 , bearings  49 , tube cover  51 , input  53  and output  55 . Fluid pump  43  also includes a cable to electrically couple the fluid pump to control circuitry of PTD  39 . 
     Pump bay  29  is an opening within device housing  19  large enough to accept fluid pump  43  and allow pump bay door  38  to lie flush with the device housing when the pump bay door is in the closed configuration. Channel  37  is disposed just inside of the perimeter of pump bay  29 . Channel  37  directs, or channels, uncontained fluid on device housing  19  that flows toward pump bay  29  away from entering the interior of the pump bay. An uncontained fluid may be water, saline, alcohol, blood, or any other fluid that may come into contact with PTD  39 . 
     Pump bay door  38  rotates about a longitudinal axis of hinges  41 A and  41 B when the physician or other user lifts the pump bay door from the closed configuration into the open configuration. As shown in  FIG. 5 , Pump bay door  38  may lock closed with a latch, snap fit, or other locking mechanism. In some embodiments, pump bay door  38  may mate with a rubber seal around the perimeter of pump bay  29  such that fluid pump  43  is protected from any uncontained fluid that comes into contact with device housing  19 . In other embodiments, hinges  41 A and  41 B may include springs that provide a moment arm bias to keep pump bay door  38  open when the door is not locked in the closed configuration. 
     Fluid pump  43  is a peristaltic pump that does not come into contact with the fluid being pumped. A flexible tube (such as tube  18  from  FIG. 1 ) includes an inflow opening placed within a first container and an outflow opening opposite the inflow opening. The outflow opening is attached to a therapy device that delivers the fluid. A middle section of flexible tube is placed within tube channel  47 , between rotor  45  and tube cover  51 . In this embodiment, the inflow opening end of the flexible tube is located in the direction of input  53  and the outflow opening is located in the direction of output  55 . 
     PTD  39  operates pump  43  by rotating rotor  45  in a counter-clockwise direction to move fluid forward within the flexible tube from input  53  to output  55 . As rotor  45  rotates, bearings  49  roll over the flexible tube and displace fluid within the flexible tube in the direction of the rotor. Rotor  45  may also rotate in the clockwise direction to move fluid in the reverse direction. The fluid delivery rate produced by fluid pump  43  is a function of the inner diameter of the flexible tube and the rotational speed of rotor  45 . In some embodiments, the flexible tube may include more than one tube sections. For example, the flexible tube within tube channel  47  may connect to a separate inflow tube and an outflow tube. 
     Securing mechanisms  57 A and  57 B secure fluid pump  43  within pump bay  29 . In the embodiment of  FIG. 5 , mechanisms  57 A and  57 B are Phillips head screws that are inserted through a base of fluid pump  43  to the interior of pump bay  29 . Pump bay  29  may include threaded holes within a bracket or mounting piece that accept securing mechanisms  57 A and  57 B. In alternative embodiments, securing mechanisms other than screws may be used. For example, pins, latches, sliding guides, or another type of mechanism may secure fluid pump  43  within pump bay  29 . 
     A user, such as a field technician or the physician, may remove fluid pump  43  in the event that the fluid pump fails or a different fluid pump is needed within PTD  39 . Being able to remove and replace fluid pump  43  allows PTD  39  to be used with a variety of therapies or to be upgradeable as system components improve to better treat patient  12 . 
     Fluid pump  43  may pump fluid in a different manner than described with respect to the peristaltic pump. Possible types of other positive displacement pumps may include an internal gear pump, and external gear pump, a vane pump, a flexible member pump, a lobe pump, a circumferential piston pump, or a screw pump. While these pumps are rotary pumps, reciprocating pumps may be used in some embodiments. In alternative embodiments, dynamic or centrifugal pumps may also be used as fluid pump  43 . 
       FIG. 6  is a top view of a internal gear fluid pump in an open pump bay of an example generator system. As shown in  FIG. 6 , PTD  59  is an alternative embodiment of PTD  14  and  39 . The partial view of PTD  59  includes opened pump bay door  38  attached to device housing  19  via hinges  61 A and  61 B. Pump bay  29  also includes channel  37  around the upper edge of the pump bay, similar to PTD  39 . Fluid pump  63  is disposed within pump bay  29  and attached to the pump bay via securing mechanisms  69 A and  69 B. Fluid pump  63  includes input  65  and output  67 . Fluid pump  63  also includes a cable to electrically couple the fluid pump to control circuitry of PTD  59 . 
     Pump bay  29  is an opening within device housing  19  large enough to accept fluid pump  63  and allow pump bay door  38  to lie flush with the device housing when the pump bay door is in the closed configuration. Channel  37  is disposed just inside of the perimeter of pump bay  29 . Pump bay door  38  rotates about a longitudinal axis of hinges  61 A and  61 B when the physician or other user lifts the pump bay door from the closed configuration into the open configuration. Pump bay door  38  may lock closed with a latch, snap fit, or other locking mechanism. In some embodiments, pump bay door  38  may mate with a rubber seal around the perimeter of pump bay  29  such that fluid pump  63  is protected from any uncontained fluid that comes into contact with device housing  19 . In other embodiments, hinges  61 A and  61 B may include springs that provide a moment arm bias to keep pump bay door  38  open when the door is not locked in the closed configuration. 
     Fluid pump  63  is an internal gear pump that fully encloses the fluid being pumped into and out of the fluid pump. Fluid pump  63  includes gear teeth that carry fluid from input  56  to output  67 . An input tube (not shown) connects a fluid container to input  65 , and an output tube (such as tube  18  from  FIG. 1 ) connects output  67  to a therapy device. An outer gear of fluid pump  63  drives an inner gear on a stationary pin. The outer and inner gears create voids as they move out of mesh, or when teeth are interlocked, and the fluid flows into the cavities between the gear teeth. As the outer and inner gears come back into mesh, the volume of the cavities is reduced and the fluid is forced out of, or discharged from, output  67 . In addition, a crescent shaped barrier between the outer and inner gears prevents the fluid from flowing backwards against the direction of the gears. The fluid delivery rate from output  67  is determined by the size are rotational speed of the inner and outer gears. In some embodiments, the internal gear setup may vary from fluid pump  63  described herein. 
     The input tube and output tube may attach to their respective input  65  and output  67  via a lure-lock connector. A female lure-lock connector is attached to the ends of each input tube and output tube. Each female lure-lock connector may then attach to the male lure-lock connector located at the end of each input  65  and output  67 . Each female lure-lock connector may be rotated to screw onto each male lure-lock connector and securely fasten each tube to fluid pump  63 . In some cases, a locking mechanism may not be necessary for a connection, but the locking connection may prevent tube disconnection when fluid pump  63  is used to produce high pressures. 
     Securing mechanisms  69 A and  69 B secure fluid pump  63  within pump bay  29 . In the embodiment of  FIG. 6 , mechanisms  69 A and  69 B are latches that snap over a base of fluid pump  63  to hold the pump in place. Mechanisms  69 A and  69 B may include springs that provide bias against the base. In alternative embodiments, securing mechanisms other than latches may be used. For example, pins, screws, sliding guides, or another type of mechanism may secure fluid pump  63  within pump bay  29 . 
       FIG. 7A  is an enlarged side view of an example light bar of an example generator system. As shown in  FIG. 7A , light bar  28  is a visual operation indicator that includes cover  35 , power light  56 , and therapy lights  58  and  60 . As mentioned previously, power light  56  visually indicates a system power status and therapy lights  58  and  60  visually indicate a therapy delivery status to the physician. In some embodiments, light bar  28  may secure two pieces, or more than two pieces, of screen housing  26 . 
     Lights  56 ,  58  and  60  may include any of electric light bulbs, light emitting diodes (LEDs), light pipes, or any other device that emits visible light. In the embodiment of  FIG. 7A , power light  56  is green in color and illuminates when PTD  14  is operational, e.g. the power is on. Power light  56  emits light at a wavelength between 491 nanometers (nm) and 575 nm. Therapy lights  58  and  60  each produce a blue light when ablation device  20  transmits RF energy to patient  12 . Each of therapy lights  58  and  60  emit blue light of a wavelength between 424 nm and 491 nm. In some embodiments, lights  56 ,  58  and  60  may emit light of different wavelengths, or colors. In other embodiments, lights  56 ,  58  or  60  may blink on and off at a certain rate to indicate a malfunction or other need that the physician needs to address. Alternatively, light bar  38  may include more or less lights to visually indicate power status or delivery status to the physician. 
     Cover  35  encloses lights  56 ,  58  and  60  against screen housing  26 . Cover  35  is constructed out of a translucent material, or a material that allows at least a portion of the light from lights  56 ,  58  and  60  to pass through the cover. In a preferred embodiment, the translucent material of cover  35  disperses the emitted light to simulate a glow. This softer light may be easier for the physician to look at than direct light through a clear cover  35 . However, cover  35  may be completely clear and transmit  100  percent of the emitted light in some embodiments The material of  35  may include polycarbonate, polypropylene, polyurethane, polytetrafluoroethylene, polyacetylene, polyethylene, polystyrene, or some combination of these materials. Other light transmitting materials may also be used in cover  35 . 
     Cover  35  also includes structure that allows the cover to manipulate a diffusion pattern of the emitted light. Cover  35  may include ribbing or other structures inside of the cover that separate the emitted light from lights  56 ,  58  and  60 . Cover  35  may also include a formation or cutout that allows a message to glow when light is being emitted. For example, cover  35  may include windows, icons, images, pictures, text, or other shapes extruded or printed onto the cover. In an example embodiment, light  56  may produce a glowing word “ON” when the system has power. Cover  35  may produce other lighting effects through the use of mirrors, prisms, and other light absorbing or light reflecting materials. 
     Cover  35  also includes a curved top surface that is higher at each side than in the middle. The curve of the curved top has a radius generally between 6 inches and 40 inches. Specifically, the curve has a radius between 14 inches and 24 inches. Each side of cover  28  is perpendicular to the curved top. The sides are also curved in the same direction as the curved top, but the curve of each side has a slightly smaller radius than the radius of the curved top. In some embodiments, the curved top of cover  28  may curve in the opposite direction, and each side would also curve in the opposite direction shown in  FIG. 7A . 
       FIGS. 7B and 7C  are enlarged end views of two example light bars with slightly different shapes.  FIG. 7B  shows an example cover  71 , which is an embodiment of cover  35 . Cover  71  includes sides  73  that are normal to the top of the cover. Corners  75  are at a right angle and form an edge where sides  73  meet the top of cover  71 . The dotted line indicates the top of cover  71  at the middle length of the cover. 
       FIG. 7C  shows an example cover  77 , which is an embodiment of cover  35 . Cover  77  includes sides  79  that are normal to the top surface of the cover. Corners  81  are curved to connect sides  79  with the op of cover  77 . Curved corners  81  may provide a rounded edge that allows a more continuous emission of light from cover  77  when compared to corners  75  of cover  71 . In some embodiments, sides  73  or  79  may not be perpendicular to the top of covers  71  or  77 , respectively. For example, sides  73  may be at an angle greater than 90 degrees with respect to the top of cover  71 , such that the distance between the sides is greater at the bottom of cover  71  than the distance between the sides at the top of cover  71 . 
       FIG. 8A  is an enlarged side view of an example removable connector board. As shown in  FIG. 8A , connector board  46  includes face plate  83 , securing mechanisms  85 A- 85 F (collectively securing mechanisms  85 ), accessory port  48  and accessory port  50 . Face plate  83  mates against device housing  19  to prevent PTD  14  internal circuits and mechanisms from being damaged during use. 
     In the example of  FIG. 8A , securing mechanisms  85  are screws that lock into helical tapped holes of device housing  19 . More or less securing mechanisms may be used in connector board  46 . Securing mechanisms  85  also coupled secures connector board  46  into the connector board port  99  (shown in  FIG. 8B ) that is electrically coupled to a motherboard of PTD  14  to enable the PTD operation. In this manner, connector board  46  is removably coupled to connector board port  99 . In some embodiments, securing mechanisms other than screws may be used to secure connector board  46 . For example, one or more latches or clips may be used instead of screws. Connector board  46  may also slide into tracks within device housing  19  and snap into place. 
     As described above, accessory port  48  transfers RF energy generated by a signal generator within PTD  14 . The signal generator is a specific type of energy source that may be within PTD  14 . Accessory port  50  provides an attachment for a ground electrode. Another accessory port may be provided to attach a video monitoring device. In other embodiments, connector board  46  may include more or less accessory ports than accessory ports  48  and  50 . For example, connector board  46  may only have an antenna if the connector board is designed to communicate with other devices. Other examples include connector board  46  including a plurality of accessory ports to support a 12-lead electrocardiogram (ECG) when the connector board is designed to diagnose cardiac dysfunction. PTD  14  may perform the function of delivering a therapy, presenting therapy data to a user or another device, or communicate directly with an external or implanted device. Some alternative peripheral accessories to ablation device  20  may include an ultrasound paddle, a communication antenna, or a battery recharging device. In other embodiments, connector board may support portable media slots, e.g. compact disks (CD) or digital versatile disk (DVD), a universal serial bus (USB) port, or any other port that allows PTD  14  to communicate with another media or device. 
       FIG. 8B  is a top view of an example removable connector board. As shown in  FIG. 8B , connector board  46  includes face plate  83 , accessory ports  48  and  50 , circuit board  97 , multiplexer  87 , processor  89 , memory controller  91  and memory  93 . Connector board  46  also includes multi-pin connector  95 . Connector board port  99  includes slot  101  that accepts multi-pin connector  95 , wherein connector board port is coupled to a motherboard or processor of PTD  14 . Connector board  46  does not include an enclosure that surrounds the connector board, but other connector boards may include an enclosure that would create a sealed module that is removable from connector board port  99  and PTD  14 .\ 
     Circuit board  97  electrically couples the components of connector board  46 . Circuit board  97  is a printed circuit that may also provide structural rigidity to hold each component. Multiplexer  87  controls the electrical signals from processor  89  to accessory ports  48  and  50 . Processor  89  processes information from a motherboard of PTD  14  and uses instructions stored in memory  93  to deliver the appropriate electrical signals to ablation device  20 . Memory  93  may also store data related to the operation of ablation device  20  and data related to identifying the type or identity of the ablation device connected to connector board  46 . 
     In some embodiments, connector board  46  may also include a device identity sensor that recognizes ablation device  20 . Processor  89  may then perform some function based upon the recognized device identity sensor. Processor  89  may enable a therapy, enable a test program that diagnoses PTD  14 , or allow patient  12  data to be transferred to another device. Processor  89  may also then load software associated to the recognized ablation device  20 . In other embodiments, memory  93  may recognize that the particular ablation device  20  has been used previously and prevent the physician from using the ablation device because a new ablation device should be used for patient  12 . The device identity sensor provides a mechanism, similar to a key, that enables a user to perform certain functions with PTD  14 . 
     In alternative embodiments, connector board  46  may not include a separate processor to control the operation of the connector board. In these embodiments, connector board  46  may not include any processing circuitry, as the connector board may only transfer electrically signals by a motherboard or other circuitry within PTD  14 . In addition, the motherboard may detect which type of connector board is electrically coupled to connector port  99 . 
     Multi-pin connector  95  may be constructed in a different configuration to connect PTD  14  and connector board  46 . For example, multi-pin connector  95  may include a four-pin snap connector. Any connector may be used based upon whether connector board  46  utilizes digital or analogue signals, or both. 
       FIG. 9  is functional block diagram illustrating components of an exemplary generator system. In the example of  FIG. 9 , PTD  14  includes a processor  68 , memory  70 , screen  72 , connector block  74 , RF signal generator  76 , pump  78 , telemetry interface  80 , USB circuit  82 , power source  84 , and light bar circuit  86 . As shown in  FIG. 9 , connector block  74  is coupled to cable  16  for delivering RF energy produced by RF signal generator  76 . Pump  78  produces pressure to deliver fluid through tube  18 . 
     Processor  68  controls RF signal generator  76  to deliver RF energy therapy through connector block  74  according to therapy parameter values stored in memory  70 . Processor  68  may receive such parameter values from screen  72  or telemetry interface  80  or USB circuit  82 . When signaled by the physician, which may be a signal from the ablation device  20  conveyed through connector block  74 , processor  68  communicates with RF signal generator  76  to produce the appropriate RF energy. As needed, pump  78  provides fluid to irrigate the ablation site or provides fluid to the electrode during wet electrode ablation. 
     In a preferred embodiment, the RF signal generator may have certain performance parameters. In this exemplary case, the generator may provide RF energy into two delivery channels with a maximum of 50 Watts per channel. Other embodiments may include generation in excess of 100 watts for one channel. Duty cycles of the energy may alter the total power capable of being produced. In other examples, the ramp time for a 50 Watt change in power may occur in less than 25 milliseconds, and the output power may be selected in 1 Watt steps. The maximum current to be provided to the patient may be 2 Amps, and the maximum voltage may be 180 Volts. Other embodiments of the signal generator may have different power capabilities as needed by the intended use of PTD  14 . 
     Connector block  74 , e.g. connector board  46 , may contain an interface for a plurality of connections, not just the connection for cable  16 . These other connections may include one for a return electrode, a second RF energy channel, or a separate temperature sensor. As mentioned previously, connector block  74  may be a variety of blocks used to diagnose or treat a variety of diseases. All connector blocks may be exchanged and connect to processor  68  for proper operation. Pump  78  may be replaceable by the physician to replace a dysfunctional pump or use another pump capable of pumping fluid at a different flow rate. 
     Processor  68  may also control data flow from the therapy. Data such as RF energy produced, temperature of tissue, and fluid flow may be channeled into memory  70  for analysis. Processor  68  may comprise any one or more of a microprocessor, digital signal processor (DSP), application specific integrated circuit (ASIC), field-programmable gate array (FPGA), or other digital logic circuitry. Memory  70  may include multiple memories for storing a variety of data. For example, one memory may contain therapy parameters, one may contain PTD operational files, and one may contain therapy data. Memory  70  may include any one or more of a random access memory (RAM), read-only memory (ROM), electronically-erasable programmable ROM (EEPROM), flash memory, or the like. 
     Processor  68  may also send data to USB circuit  82  when a USB device is present to save data from therapy. USB circuit  82  may control both USB ports in the present embodiment; however, USB circuit  82  may control any number of USB ports included in PTD  14 . In some embodiments, USB circuit may be an IEEE circuit when IEEE ports are used as a means for transferring data. 
     The USB circuit may control a variety of external devices. In some embodiments, a keyboard or mouse may be connected via a USB port for system control. In other embodiments, a printer may be attached via a USB port to create hard copies of patient data or summarize the therapy. Other types of connectivity may be available through the USB circuit  82 , such as internet access. 
     Communications with PTD  14  may be accomplished by radio frequency (RF) communication or local area network (LAN) with another computing device or network access point. This communication is possible through the use of communication interface  80 . Communication interface  80  may be configured to conduct wireless or wired data transactions simultaneously as needed by a user, e.g., a physician or clinician. In some embodiments, communication interface  80  may be directly connected to connector block  74 . 
     PTD  14  may communicate with a variety of device to enable appropriate operation. For example, PTD may utilize communication interface  80  to monitor inventory, order disposable parts for therapy from a vendor, and download upgraded software for a therapy. In some embodiments, the physician may communicate with a help-desk, either computer directed or human staffed, in real-time to solve operational problems quickly. These problems with PTD  14  or a connected ablation device may be diagnosed remotely and remedied via a software patch in some cases. 
     Screen  72  is the interface between PTD  14  and the physician. Processor  68  controls the graphics displayed on screen  72  and identifies when the physician presses on certain portions of the screen  72 , which is sensitive to touch control. In this manner, screen  72  operation may be central to the operation of PTD  14  and appropriate therapy or diagnosis. 
     Processor  68  also determines the operation of light bar circuit  86 . In the present embodiment, processor turns on a green light when PTD power is on while blue lights are illuminated when therapy is being delivered. Processor  68  may be capable of controlling any number of different lights which illuminate light bar  28 . 
     Power source  84  delivers operating power to the components of PTD  14 . Power source  84  may utilize electricity from a standard  115  Volt electrical outlet or include a battery and a power generation circuit to produce the operating power. In other embodiments, power source  84  may utilize energy from any outlet that provides between 100 and 240 Volts. In some embodiments, the battery may be rechargeable to allow extended operation. Recharging may be accomplished through the 115 Volt electrical outlet. In other embodiments, traditional batteries may be used. 
     In some embodiments, signal generator  76  may be a different type of energy source. For example, the energy source may convert power from power source  84  to produce steam, mechanical energy, or any other type of output that may perform work on patient  12 . Other energy may be laser energy or ultrasound energy. In this manner, the energy source may produce electrical, chemical, or mechanical energy. 
       FIG. 10  is a flow diagram illustrating an example technique for operating the generator system in attaching a ablation device and providing therapy to a patient. In the example of  FIG. 10 , system  10  delivers therapy. In another embodiment, system  10  may diagnose a condition, or diagnose a condition and provide an associated therapy. 
     In this embodiment, a physician (a user) turns on the generator ( 88 ). Once the system is powered up, the system looks for a connected device ( 90 ). If a device is not connected, a prompt is given to the user to connect a device ( 92 ). Once a device is connected, the system checks the device to determine if it is compliant with the system ( 94 ). If it is not, an error message may be issued to the user indicating that the device is not compliant with the system ( 96 ). 
     If the device is compliant, the system records the device identification number (ID) to memory so that the system may log the use of that device ( 98 ). The PTD may then load the associated software to operate the therapy of the connected device ( 100 ). Once the software is loaded, the user may begin to deliver therapy to the patient ( 102 ). After therapy is concluded, therapy data may be saved to the memory of PTD  14  and to a smart memory chip within the connected ablation device ( 104 ). With therapy data contained within the device, the device could be examined at a later date for quality control or therapy investigation reasons. 
     After data has been saved, the system may prompt the user to disconnect the ablation device ( 106 ). Once disconnected, the system may wait for the user to begin another therapy session ( 108 ). If another session is desired, the system begins again with block  90 . If no new session is desired, the generator may shut down ( 110 ). 
     This example of system operational flow is only an example, and other embodiments may be different. For example, the user may have much more flexibility in operation instead of being forced to the next step in therapy. The order of steps may also be rearranged depending on the user&#39;s preference or the therapy being delivered. The system may also enable a phantom operation mode to train new users on the system. In this case, a device may not be connected, or the connected device may be non-functional. 
       FIG. 11  is a flow diagram illustrating an example technique for identifying a connected ablation device and determining its status before providing therapy to a patient. In the example of  FIG. 11 , a ablation device is connected to the system in order for therapy to be delivered. The device is connected to the system, the generator in this case, by the user ( 112 ). Immediately, the system interrogates the connected ablation device to determine if it is compliant ( 114 ). 
     If the device is compliant, the system continues by loading the associated programs to control the connected ablation device ( 116 ). If the device does not comply with the system, the system determines if the device has been used before ( 126 ). This may be determined by either locating data within a smart memory chip of the ablation device or locating the ablation device ID within the PTD and any associated data. If the device has not been used before, but it is still not compliant with the system, a non-compliant message may be delivered to the user ( 128 ). If the device has been used before, an expiration message may be delivered to the user ( 130 ). In some cases, device may only be used once, with one patient. In other cases, a device may be used with a plurality of patients, but the operational life of the ablation device is limited to a set number of uses. For this reason, a device may be expired after a predetermined number of uses. In other embodiments, the smart memory chip may deem a device expired when it become dysfunctional due to a mechanical or electrical failure. 
     If an acceptable ablation device is connected, the ID number of the ablation device is saved to memory once the software is loaded ( 118 ). The user is then able to perform any appropriate therapy with the system ( 120 ). After therapy is concluded, a log of data encompassing the therapy delivered is loaded into the smart memory chip of the ablation device ( 122 ). Once this is completed, the user may be notified that the system is ready for the device to be removed ( 124 ). 
     In some embodiments, more involved operations may govern the use of ablation devices. For example, the system may check for older versions of ablation devices or determine the status of a device when multiple uses are acceptable. In other embodiments, a variety of error messages may be issued to the user. These error messages may even suggest possible methods to troubleshoot a malfunctioning device which should be compliant. 
       FIG. 12  is an exemplary screen shot of the main menu provided by the user interface. All boxed items in the following screens are interactive, meaning that the user may touch that portion of the screen to select that item. Although the following sample screen shots are used in this embodiment, any number of variations may be made to this graphic interface as ablation devices, diagnosis devices, or functionality are modified within the system. 
     In this main menu, a few options reside for the user. Therapy box  132  indicates that “TUNA Therapy,” or prostate ablation, would be delivered if the user pressed box  132 . In other embodiments, an plurality of therapy boxes may be present, depending on the device or devices connected to PTD  14 . When the user selects one of the boxes, that program is initialized. 
     Language box  134  may reside at the lower left hand corner of the screen. The selected language may be indicated, as English is shown in box  134 . If the user desires to change the language in the user interface, pressing the box may bring up another menu which includes other supported languages. Selecting one of those languages displayed may immediately change the language used in the interface. In some embodiments, English may always be the default language, while other embodiments may save the default language as the last selected language from box  134 . 
     Volume may also be modified on the main menu screen. Volume up triangle  136  may increase the volume one level for each time it is selected. Alternatively, volume triangle  138  may decrease the volume one level for each time it is pressed. Upon a volume change, an audible note may be played at the newly selected volume level. In some embodiments, a numeric indicator of the volume level may be shown for a certain period of time upon a volume change. In other embodiments, the shape of triangle  136  may be a square, circle, oval, or any other shape. 
       FIG. 13  is an exemplary screen shot of the delivery screen when the system becomes operational. Before the physician begins therapy, this screen displays the delivery information. Message box  140  indicates that the system is ready for the physician to begin therapy. Indicator  141  is associated with message box  140  and provides a reference to the user in case the user desires to further investigate the message or error in message box  140 . In some embodiments, the manual may be printed in more languages than the user interface supports. If needed, the user may use the indicator to identify the message of message box  140  in a particular language. 
     Timer  142  indicates the time remaining for the therapy. Since the therapy has not begun, two minutes and thirty seconds remain for therapy. Check box  144  indicates how many lesions, or ablation areas, have been completed. Graph  146  displays the temperature of the tissue with respect to time. The dotted line may indicate the threshold safe temperature for the urethra. At approximately 115 degrees Celsius, an arrow indicates the target temperature for the tissue to be ablated. 
     Omega symbol  148  indicates the units of resistance, in Ohms, of the tissue between the anode and cathode for each tissue area. Letter W  150  indicates the power, in Watts, of the RF energy being delivered to each needle. Degree C  152  indicates the temperature, in degrees Celsius, of each ablation site and the urethra. In some embodiments, these indicators may be in different units as requested by the therapy or the user. As other therapies are used, other measurable may be used to monitor the therapy. 
     Graphical representations of each electrode orientation are indicated by icons to identify what measured data corresponds to what area of the patient. Icon  154  represents the left needle site, icon  156  represents the right needle site, and icon  158  represents the urethra. Each needle site shows an orientation of each needle with respect to the tissue. Icons  154 ,  156  and  158  also indicate which channel is being used to ablate tissue. Each icon may be represented by a different color to further distinguish the icon. In other embodiments, words may be used instead of graphical icons. 
     If the user desires to return to the main menu, exit box  160  may be pressed to exit the therapy screen and return to the main menu. In this embodiment, exit box  160  is the only touch spot on the screen available to the user. Therapy is begun by pressing a button or handle on the connected ablation device. Exit box  160  is a multifunction button. For example, once therapy is started, exit box  160  may change to a stop icon. In other states of PTD  14 , exit box  160  may change to other icons as well. Other embodiments may allow further control of the therapy from the touch screen. 
       FIG. 14  is an exemplary screen shot of the delivery screen when ablation therapy is being delivered. Message box  162  delivers a message to the user that a lesion is in progress. This message corresponds to the user manual, as indicated by indicator  164 . Values for tissue resistance, power, and temperature are displayed in their respective areas. The graph also shows temperature in their appropriate areas. The colors of the temperatures plotted in the graph correspond to the color of each tissue location. 
     As shown by the timer, remaining time for therapy is counting down. Upon the end of the timer, the system may provide an audible indication of elapsed time, provide a visual cue to cease therapy, or cease therapy delivery automatically. If the physician desires to prematurely end therapy, they physician may press stop box  166 . This function may be an appropriate safety measure for dysfunctional therapy or an adverse patient reaction. 
       FIG. 15  is an exemplary screen shot of the delivery screen and a temperature warning message during therapy. As indicated by the graph, the temperature of the urethra is reaching an unsafe threshold. Caution message  168  is delivered to advise the physician to irrigate the urethra with fluid to cool the tissue. Indicator  170  corresponds to an index  51  for a user to find further information related to the message. 
     In some embodiments, the system may automatically shut down therapy if safe temperature levels are breached. In this case, if the urethra was not successfully irrigated with fluid, the therapy may be discontinued automatically or by the physician. 
       FIG. 16  is an exemplary screen shot of the delivery screen displaying an error message when the therapy is terminated due to the return electrode malfunction. The return electrode allows RF energy to flow from the needle to the return electrode, sometime located on the lower back of the patient. If this return electrode is malfunctioning or removed, the patient could be injured. Warning box  172  informs the user that the return electrode is not connected to the system appropriately. Indicator  174  corresponds to a message index that may be used by a user to find more information related to the problem or message. 
     In this exemplary embodiment, therapy has been suspended until the return electrode is replaced. Once it is, therapy may resume as normal. In some embodiments, a malfunction of the system may force therapy shut down. If this occurs, the therapy would need to be restarted after the system is operational again. 
     Warnings such as the one displayed in  FIG. 12  may not be the only warning issued by PTD  14 . Other warnings may be delivered as well, such as dysfunctional needles, improper impedances and high power output. Each warning may be accompanied by a suggestion for correcting the problem. 
       FIG. 17  is an exemplary screen shot of the delivery screen when the therapy is completed. Message box  176  indicates that the lesion created by ablation therapy is complete. Additional information is provided on how to proceed. Indicator  178  shows the user where to find for information regarding the message in the user manual. 
     Therapy was completed at a site in this screen shot; therefore, one lesion was created. This lesion number is indicated by check box  144 . As more lesions are created by the therapy, the number displayed by check box  144  will increase appropriately. Since each patient is different, the number of lesions required to effectively treat a patient may vary from one to many more than one. If no more lesions are required by the user, the user may exit to the menu by pressing exit box  160 . 
       FIG. 18  is an exemplary screen shot of the post session menu. The user may be presented with a variety of choices. By pressing resume box  182 , the user may re-enter the therapy screen that the user just exited from. In this case, the user would be free to then create more lesions. If a new session is required, the user may press new session box  184 . This option may be used to treat another patient or provide therapy to another location. By pressing quit box  186 , the user may return to the main menu to select a new therapy or turn off PTD  14 . 
     In some embodiments, more options may be available for the user. This screen of  FIG. 14  may contain additional features which could be modified to the user&#39;s preferences. For example, the user may decide to change the color scheme of the indicators, modify the volume, or request different information to be displayed during therapy. 
     While the screen shots provided in  FIGS. 12  though  18  show one type of display for use with PTD  14 , many other display formats may be used. These formats may include more or less user modifications, different sized indicators, different colors, pop-up messages, or any other format for displaying the described information pertinent to this RF ablation therapy or any other therapy described herein. 
     Various embodiments of the described invention may include processors that are realized by microprocessors, Application-Specific Integrated Circuits (ASIC), Field-Programmable Gate Arrays (FPGA), or other equivalent integrated logic circuitry. The processor may also utilize several different types of storage methods to hold computer-readable instructions for the device operation and data storage. These memory and storage media types may include a type of hard disk, random access memory (RAM), or flash memory, e.g. CompactFlash or SmartMedia. Each storage option may be chosen depending on the embodiment of the invention. While the implantable IMD  18  may contain permanent memory, external programmer  16  may contain a more portable removable memory type to enable easy data transfer for offline data analysis. 
     The preceding specific embodiments are illustrative of the practice of the invention. It is to be understood, therefore, that other expedients known to those skilled in the art or disclosed herein may be employed without departing from the invention or the scope of the claims. 
     Many embodiments of the invention have been described. Various modifications may be made without departing from the scope of the claims. These and other embodiments are within the scope of the following claims.