Patent Publication Number: US-2010119411-A1

Title: Apparatus and method to deliver a sterile, filled syringe to a user

Description:
BACKGROUND 
     Use of sterile syringes is a standard industry practice in the medical field. Prior to filling a syringe with a medicinal or therapeutic agent of choice, the filled syringe is sterilized to remove potential contaminants. In many cases, the syringes are packaged in sterilized conditions. Additionally, some syringes may come prefilled with therapeutic agents and delivered in a sterilized condition within hermetically sealed pouches which are delivered to treatment facilities. However, pre-filled sterilized syringes have the limitation of coming in pre-determined concentrations and amounts. Additionally, some therapeutic agents such as ozone are not suitable for use in prefilled syringes due to the shelf life of the agents. 
     Ozone as a therapeutic agent of choice may be used as a curative for herniated disks, rheumatoid arthritis, and osteoarthritis. Ozone may also be used therapeutically to treat inflammation such as bursitis of a knee, shoulder, or hip. Additionally, there may be veterinary applications of ozone to animals suffering from disc and degenerative diseases. 
     Lavage of a surgical space prior to placement of a permanent surgical implant such as a hip or knee prosthesis, or pacemaker or treatment of an infected joint can be facilitated by the use of medical ozone as a sterilizing substance. Similarly, a colostomy stoma can be created such that the adhesive disk is infused with ozone to aid in healing and inhibit infection. The post surgical recovery from sternotomy after cardiac surgery is often complicated by wound infection. Placement of a resorbable catheter in the wound that could be irrigated with ozone would aid healing. Indeed, many wounds could have a resorbable multisided hole catheter placed in it to allow ozone to be injected through it. This would have anti-infective, analgesic, and wound healing properties. This would shorten recovery time and decrease complication rates after surgery. Ozone administration can be performed by directly delivering an ozone gas mixture, or a liquid or gel that contains ozone, to the treatment site. 
     Ozone could be applied to a site of high probability of infection such an abdominal incision/wound after appendectomy, or urgent colectomy with colostomy or after percutaneous endoscopic cholecystectomy. Endoscopic procedural infusion of ozone and trans catheter infusion of ozone can be used to inhibit the complications due to endoscopic medical intervention or image guided or non-image guided catheter based intervention, for example, in endoscopic evaluation of the pancreatic duct. Dental injection of ozone may also augment the preparation and repair of dental cavities, and aid in reduction of root canal inflammation or periodontal disease. The therapeutic and medicinal applications of ozone are being continually researched. 
     In some applications, ozone is also used for sterilization purposes. Unless bound by other molecular couplings, ozone may break down to dioxygen within 20 to 30 minutes or so at atmospheric pressure. Ozone is highly reactive with many substances not desired in the human body including yeast, mold, water borne parasites and harmful bacteria. Ozone is therefore used as a sterilizing agent for medical equipment in hospitals and to sterilize food and laundry in care facilities, as well as in many other environments and applications. 
     As the success of ozone gas therapy continues to gain recognition in medical and therapeutic applications, there is a lack of conventional methods and products to effectively implement ozone generation and ozone sterilization. 
     SUMMARY 
     According to described embodiments, a syringe dispenser to deliver a sterile, filled syringe to a user is disclosed. The syringe dispenser includes a controller to accept input from the user and to convert the input into an electrical control signal used primarily within the apparatus. The syringe dispenser also includes an ozone generator coupled to the controller. The ozone generator generates ozone on demand according to the input from the user. For instance, the user may input a parameter for a concentration and/or a volume of ozone. Additionally, a syringe preparation station is coupled to the ozone generator. The syringe preparation station sterilizes the syringe with a first amount of the ozone and fills the syringe with a second amount of the ozone. 
     In another embodiment, a syringe dispenser to deliver a sterile, filled syringe to a user may additionally include an ozone sensor coupled to the ozone generator and to the controller. The ozone sensor senses a characteristic of the ozone. The syringe dispenser also may include a scrubber to receive excess ozone from the ozone generator and dispose of the excess ozone. Other embodiments of the syringe dispenser are also described. 
     Embodiments for a method of autonomously sterilizing and filling a syringe are also described. The method includes automatically moving the syringe from a syringe repository to a sterilization station and generating ozone on demand from an oxygen source. The generated ozone is used both to sterilize the syringe and to fill the syringe. Other embodiments of the method are also described herein. 
     Other aspects and advantages of embodiments of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, illustrated by way of example of the principles of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  depicts a schematic diagram of one embodiment of a syringe dispenser to deliver a sterile, filled syringe to a user. 
         FIG. 2  depicts a block diagram of one embodiment of a syringe dispensing system to deliver a sterile, filled syringe to a user. 
         FIG. 3  depicts one embodiment of a process flow diagram for generating ozone from water in the syringe dispenser of  FIG. 2 . 
         FIG. 4  depicts one embodiment of a process flow diagram for generating ozone from air in the syringe dispenser of  FIG. 2 . 
         FIG. 5  depicts one embodiment of a process flow diagram for generating ozone from steam in the syringe dispenser of  FIG. 2 . 
         FIG. 6  depicts a flow chart diagram of an embodiment of a method for autonomously sterilizing and filling a syringe. 
         FIG. 7  depicts a flow chart diagram of an embodiment of a method for generating ozone according to user input. 
     
    
    
     Throughout the description, similar reference numbers may be used to identify similar elements. 
     DETAILED DESCRIPTION 
       FIG. 1  depicts a schematic diagram of one embodiment of a syringe dispenser  100  to deliver a sterile, filled syringe  110  to a user. The illustrated syringe dispenser  100  includes a syringe  110 , an ozone generator  120 , a syringe preparation station  130 , a pump  160 , and a scrubber  170 . The various components of the syringe dispenser  100  are coupled together by several channels of tubing, designated as T 1 -T 8 , as well as several valves, designated as V 1 -V 5 . Although the syringe dispenser is illustrated with several components and interconnections, other embodiments may include fewer or more components to implement more or less functionality. Additionally, some embodiments may implement different connection paths through the same or different channels of tubing and valves, or other connecters. 
     In general, the ozone generator  120  generates ozone on demand according to input from a user. The syringe preparation station  130  contains the syringe  110  and is connected to the ozone generator  120 . The syringe preparation station  130  is configured to sterilize the syringe  110  with a first amount of the generated ozone and to fill the syringe  110  with a second amount of the generated ozone. The pump  160  may activate to facilitate moving the ozone from the ozone generator  120  to the syringe preparation station  130  and/or from the syringe preparation station  130  to a scrubber or ozone destruction unit  170 . The scrubber  170  decomposes the excess ozone evacuated from the syringe preparation station  130 . Additionally, the scrubber  170  may receive and destroy the excess ozone from the syringe  110 . In some embodiments, the scrubber  170  is a charcoal, potassium iodide (KI), magnesium dioxide (MnO 2 ), and/or copper oxide (CuO) filter. In other embodiments, the scrubber  170  is a thermal-type ozone destruct unit. 
     Referring more specifically to  FIG. 1 , the ozone generator  120  can be based on any known ozone generator. The ozone generator  120  connects to the scrubber  170  and the syringe preparation station  130  via the flexible tubing and valves for selectively directing the flow of gas therebetween. More specifically, a first channel of tubing T 1  connects the generator  120  to a three-way valve V 1 . A second channel of tubing T 2  connects the valve V 1  to another three-way valve V 2 . The valve V 2  is further connected to the scrubber  170  through another channel of tubing T 3 . A third three-way valve V 3  is connected by another channel of tubing T 4  to the second three-way valve V 2 . The valve V 3  is also connected to the syringe preparation station  130  by another channel of tubing T 5  and to the syringe  110  within the syringe preparation station  130  by a separate channel of tubing T 6 . The tubing is made of any suitable material, such as silicone or Teflon of the known medical types, and has a diameter and wall thickness to withstand the pressure of ozone gas being carried therethrough. The valves, also known as stopcocks, are also of the known medical type and have fittings complementary to the various portions of tubing. 
     In the illustrated embodiment, the syringe  110  includes a three-way valve V 4  and a needle  180 . The syringe  110  may be made of polyethylene, or another similar material, to resist the corrosive effect of ozone. The three-way valve V 4  is releasably connected directly to the valve V 5 , providing a selective pathway between the syringe  110  and the ozone generator  120  and/or the scrubber  170 . 
     The valves V 1  and V 2  have a first position to allow the ozone generator  120  to transfer ozone to the syringe preparation station  130  through the tubing channels T 1 , T 2 , and T 3 , as well as the valve V 3 . The valve V 3  has a first position which allows the ozone to flow from the tubing channel T 4  into the syringe preparation station  130  via the tubing channel T 5 . By directing the ozone into the syringe preparation station  130  via the tubing channel T 5 , the syringe  110  within the syringe preparation station  130  may be sterilized as the ozone collects within the syringe preparation station  130 . Further details about sterilizing the syringe  110  in this manner are provided below. 
     The valve V 3  has a second position which allows the ozone to flow from the tubing channel T 4  into the syringe preparation station  130  via the tubing channel T 6 . By directing the ozone into the syringe preparation station  130  via the tubing channel T 6 , the syringe  110  may be filled with a volume of the ozone from the ozone generator  120 . More specifically, the ozone is directed through the valve V 5 , which may be used to connect to the syringe  110 , and the ozone is directed into the valve V 4  to fill the syringe  110 . Further details about filling the syringe  110  with the ozone in this manner are provided below. 
     Thus, by toggling the valve V 3  when the ozone generator  120  is on, the syringe  110  is sterilized within the syringe preparation station  130  and the syringe  110  is filled with ozone. In other embodiments, the valve V 3  may be omitted and the valve V 4  may be configured to fill the syringe  110  and to release additional ozone into the syringe preparation station  130  for sterilizing the syringe  110 . Therefore toggling the valve V 4  will allow sterilizing the syringe  110  with a first amount of ozone from the ozone generator  120  and filling the syringe  110  with a second amount of ozone from the ozone generator  120 . Other embodiments may implement similar functionality using fewer or more valves and/or tubing channels, or configurations thereof. 
     In some embodiments, excess ozone from the syringe preparation station  130  is evacuated to the scrubber  170  through the tubing channels T 7 , T 8 , T 2 , and T 3 . In some embodiments, the pump  160  creates a vacuum condition within the syringe preparation station  130 , and the valves V 1  and V 2  direct the evacuated ozone into the scrubber  170 . In particular, the valve V 1  has a second position which facilitates the flow of ozone from the pump  160  to the valve V 2 . Therefore, when the valves V 1  and V 2  are in the second position, the pump  160  may evacuate excess ozone from the syringe preparation station  130  into the scrubber  170 . It should be noted that the pump  160  may also be placed in other channels between valves, or multiple pumps may be placed throughout the syringe dispenser  100  to facilitate ozone flow and/or evacuation. In some embodiments, the syringe dispenser  100  may operate without a pump. In some embodiments, the ozone generator  120  includes an internal pump. 
     Additionally, excess ozone from the ozone generator  120  may be directed to the scrubber  170  via the tubing channels T 1 , T 2 , and T 3 , as well as the valves V 1  and V 2 . In particular, the valve V 2  has a second position which blocks flow to the tubing channel T 4  and the valve V 3 . As an additional safeguard, the valve V 5  has a closed position to effectively cap the tubing channel T 6 , preventing flow from the tubing channel T 6  to the syringe  110 . Therefore, when valve V 2  is in the second position and valve V 1  is in the first position, any ozone generated by ozone generator  120  is captured by scrubber  170 . 
     Any excess ozone still present in the tubing may also be captured by the scrubber  170  and thereby reduce and/or substantially eliminate the unwanted escape of ozone into the atmosphere where it may harm the operator or other individuals proximal to apparatus  100 . Once generator  120  is turned “off” after filling and sterilizing syringe  110  as described above, valves V 1 , and V 2  are each moved from their respective first position to their respective second position, and valve V 3  is toggled to open up channels  140  and  150   
     The valve V 4  also has a second position which prevents backflow from the syringe  110  to the valve V 5  (or the open fitting on the valve V 4  that connects to the valve V 5 ). Additionally, the valve V 4  may prevent the flow of ozone out of the needle  180  of the syringe  110 , in the absence of sufficient pressure or mechanical control of the valve V 4 . Thus, once the syringe  110  is filled with ozone, the valve V 4  is placed in the second position to retain the ozone within the syringe  110  even after the syringe  110  is disconnected from the valve V 5  and dispensed to a user. 
     Once the syringe  110  is charged, or filled, with ozone, the syringe  110  can be dispensed from the syringe dispenser  100  so that the syringe  110  can be used to administer ozone, for example, to a target area of a patient. Thus, the valve V 4  also has a third position that places the syringe  110  in communication with needle  180  for discharging the ozone from the syringe  180 . 
       FIG. 2  depicts a block diagram of one embodiment of a syringe dispensing system  200  to deliver a sterile, filled syringe  110  to a user. The illustrated syringe dispensing system includes the syringe dispenser  100  of  FIG. 1 , as well as an oxygen source  205  and a water source  210 . In general, the syringe dispenser  100  receives user input (e.g., ozone concentration (%), ozone volume (cc), etc.) and oxygen, air, or water in order to generate the ozone. The illustrated syringe dispenser includes the ozone generator  120 , the syringe preparation module  130 , a controller  220 , and a syringe repository  225 . 
     The controller  220  is connected to the ozone generator  120  via a first communication channel  230 , to the syringe preparation station  130  via a second communication channel  235 , and to the syringe repository via a third communication channel  240 . In one embodiment, the controller  220  accepts the user input from a user and converts the user input into at least one electrical control signal transferred over communication channels  230 ,  235 , and  240 . The depicted controller  220  includes a user interface  245  and a memory device  250 . The user may input a parameter such as a concentration of ozone or a volume of ozone into the user interface  245 , which stores the user input in the memory device  250 . The user may input the concentration and volume, or other parameters, through the user interface  245  such as a keypad to the controller  120  or through other methods such as voice recognition or document scanning. Alternatively, the parameters (e.g., concentration and volume) may be stored in a memory  250  from source other than the user interface  245 . Based on the stored parameters or the user input directly, the controller  220  then may send electrical signal(s) to the ozone generator  120  to control the generation of a volume and concentration of ozone to be generated. Other parameters to characterize the ozone may also be input by the user via the user interface  245  or stored in the memory device  250 . 
     In one embodiment, the ozone generator uses oxygen from the oxygen source  205  and/or water from the water source  210  to generate the ozone. Additional details about generating ozone from air are shown in  FIG. 4  and described below. Additional details about generating ozone from water are shown in  FIG. 3  and described below. 
     Generally, oxygen constitutes about 88.8% of the mass of water and about 20.9% of the volume of air. Therefore, a larger amount of ozone may be generated from a volume of water than from a comparable volume of air. In one embodiment, the water source  210  provides sterile, deionized water to facilitate ozone generation. In another embodiment, the water source  210  provides tap or soft water into the ozone generator  120 . 
     In one embodiment, the controller  220  also controls the valves depicted in  FIG. 1  and other mechanical systems (not shown) within the syringe dispenser  100 . For example, the controller  220  may control a mechanical element to move the syringe  110  within the dispenser  100  from the syringe repository  225  to the syringe preparation station  130 . The syringe repository  225  may hold one or several unfilled syringes prior to sterilization and filling of the stored syringes. Additionally, in some embodiments, the syringe dispenser  100  may include a syringe dispenser (not shown) coupled to the syringe repository  225  to provide an unfilled syringe to a user prior to sterilization and/or filling. In some embodiments, the syringe dispenser  100  includes a separate syringe repository (not shown) which stores used syringes for disposal. In some embodiments, the used syringes may be sterilized prior to storage and batch disposal. Further, in some applications, it may be useful to sterilize used syringes that have been used previously, either for sanitation and disposal or for reuse (in jurisdictions with applicable safety standards). 
     The syringe preparation station  130  may include a dispensary to vend the sterile, filled syringe  110  to a user. The dispensary may be part of the syringe preparation station  130 . Alternatively, the dispensary may be separate from the syringe preparation station  130 . 
       FIG. 3  depicts one embodiment of a process flow diagram  300  for generating ozone from water in the syringe dispenser  100  of  FIG. 2 . In one embodiment, a water reservoir  310  holds water for a water treatment module  320 . The water treatment module  320  treats the water using deionization and other conventional treatment methods to supply deionized water to a water intake  330 . The water intake  330  delivers the water from the water treatment module  320  to an electrochemical ozone generator  360 . The electrochemical ozone generator  360  generates ozone from the deionized water using conventional electrochemical processes. 
     In one embodiment, an ozone sensor  370  monitors the ozone generated by the electrochemical ozone generator  360 . In some embodiments, the ozone sensor  370  may communicate with the controller  220  to adjust the concentration, volume, or another characteristic of the generated ozone. Alternatively, the controller  220  may communicate a feedback signal directly to the electrochemical ozone generator  360  in order to adjust a characteristic of the generated ozone, according to the user input. The electrochemical ozone generator  360  sends the generated ozone to the syringe preparation station  130  for use in sterilizing and/or filling the syringe  110 . 
       FIG. 4  depicts one embodiment of a process flow diagram  400  for generating ozone from air in the syringe dispenser  100  of  FIG. 2 . In one embodiment, an air mover  410  brings ambient air to a dioxygen generator  420 . The air mover  410  may be a fan, a negative pressure induction device, or another type of device which facilitates the flow of air toward or into the dioxygen generator  420 . In another embodiment, the air mover  410  may supply treated air from a tank (not shown) or other source to the dioxygen generator  420 . The dioxygen generator  420  generates dioxygen on demand from the ambient air. An oxygen intake  430  moves the dioxygen from the dioxygen generator  420  into an ozone generator  450  to produce ozone of substantial purity, as monitored by the ozone sensor  370 . The ozone generator  450  sends the generated ozone to the syringe preparation station  130 . In an alternative embodiment, the air mover  410  and the dioxygen generator  420  may be omitted, and oxygen from a tank (not shown) or other source may be directly supplied to the oxygen intake  430 . In another embodiment, ambient air may be supplied directly to the oxygen intake  430 . 
     There are many types of ozone generators  450  which may be used to generate the ozone from the dioxygen. For example, ozone may be made by applying ultra violet (UV) energy or electrical discharge energy to either pure oxygen, or more commonly just plain air. Therefore, the ozone generator  450  may be a corona discharge generator or a UV light. In such embodiments, the ozone generated from the corona discharge generator or the UV light is delivered to the syringe preparation station  130  through tubing and valves such as are shown in  FIG. 1 . 
     In another embodiment, the ozone generator  450  includes a solid electrolyte oxygen separator (SEOS) to generate substantially pure oxygen on demand from the ambient air. In another embodiment, the ozone generator  450  includes a polymeric membrane electrolyte to generate substantially pure oxygen on demand from the ambient air. In another embodiment, the ozone generator  450  includes a pressure swing absorption (PSA) oxygen separator to generate substantially pure oxygen on demand from the ambient air. Other embodiments may implement a combination of two or more conventional ozone generation technologies. 
       FIG. 5  depicts one embodiment of a process flow diagram  500  for generating ozone from steam in the syringe dispenser  100  of  FIG. 2 . In the illustrated embodiment, the syringe dispenser  100  includes a steam source  510 , a dioxygen generator  420 , an ozone generator  530 , and an ozone sensor  370 . The steam source supplies steam, water vapor, or another form of H 2 O to the dioxygen generator  420  and/or the ozone generator  530 . The dioxygen generator  420  generates dioxygen from the air content in the steam. The ozone generator  530  then generates ozone from the dioxygen generated by the dioxygen generator  420 . The ozone generator  530  may include one or more of the technologies described above to generate the ozone from the dioxygen. 
     Additionally, the ozone generator  530  may generate ozone directly from the water content in the steam using, for example, the electrochemical ozone generator  360  described above. Thus, the ozone generator  530  may generate ozone from multiple oxygen sources using a combination of ozone generator technologies. In other embodiments, the ozone generator  530  may selectively generate ozone from one or more oxygen sources. Also, a condenser (not shown) may be included to facilitate the separation of the air and water components of the steam. The ozone sensor  370  monitors the generated ozone, and the ozone generator  530  sends the generated ozone to the syringe preparation station  130 , as described above. 
       FIG. 6  depicts a flow chart diagram of an embodiment of a method  600  for autonomously sterilizing and filling a syringe  110 . The illustrated method  600  includes automatically moving  610  the syringe  110  from the syringe repository  225  to a sterilization station (within the syringe preparation station  130 ) and generating  620  ozone on demand from an oxygen source. The method  600  also includes sterilizing  630  the syringe  110  with a first amount of the generated ozone within the sterilization station and filling  640  the syringe  110  with a second amount of the generated ozone. 
     Other embodiments of the method  600  may include fewer or more operations. For example, the method  600  also may include dispensing the sterilized, filled syringe  110  to a user. The method  600  also may include extracting oxygen from ambient air, for example, by moving the air to a solid electrolyte oxygen separator (SEOS), a polymeric membrane electrolyte oxygen separator, and/or a pressure swing absorption (PSA) oxygen separator to generate substantially pure oxygen. Other embodiments of the method  600  also include generating an amount of dioxygen from the ambient air and generating the ozone from the dioxygen. Some example technologies which may be implemented to generate the ozone include a corona discharge electrode, a UV light, a plasma generator, and an electrochemical ozone generator. 
       FIG. 7  depicts a flow chart diagram of an embodiment of a method  700  for generating ozone according to user input. The illustrated method  700  includes receiving  710  user input to specify a concentration and volume of the second amount of the generated ozone to be introduced into the syringe  110 . The method  700  also includes sensing  720  a characteristic of the generated ozone and altering  730  a parameter for generating the ozone to adjust the characteristic of the generated ozone. The method  700  also includes filling  740  the syringe  110  with approximately the specified concentration and volume of the second amount of the generated ozone. 
     Other embodiments of the method  700  may include fewer or more operations. For example, the method  700  also may include communicating one or more control signals between the ozone generator  120 , the controller  220 , and the ozone sensor  370 . In one embodiment, the controller  220  may process the signal from the ozone sensor  370  and control the generation of the ozone at the ozone generator  120 . The controller  220 , the ozone sensor  370 , and the communication channels within the syringe dispenser  100  are not limited to simply electrical implementations, but also may be include mechanical or electromechanical implementations. 
     The method  700  for generating ozone according to the user input also may include receiving excess ozone from the syringe  110  and disposing of the excess ozone in the scrubber  170 . Similarly, the method  700  may also include evacuating excess ozone from the sterilization station within the syringe preparation station  130  and disposing of the excess ozone in the scrubber  170 . 
     While many embodiments are described herein, at least some embodiments present a technical application with certain advantages over conventional technologies. As one example, a therapeutic administrator may use a tabletop implementation of the syringe dispenser  100  to dispense sterilized, filled syringes  110  on demand. The syringe dispenser  100  dispenses the syringe  110  in accordance with specified parameters such as ozone volume and concentration inputs for a patient. The syringe dispenser  100  automatically moves a syringe  110  from the syringe repository  225  and sterilizes the syringe  100  with ozone generate on demand from the ambient air, tap water, or another oxygen source available onsite. The syringe  110  is also filled with ozone generated on demand having the precise characteristics meeting the specified parameters. The syringe dispenser may vend the sterile and filled syringe  110  into a dispensary for on-demand access to the ozone-filled syringe  110 . 
     Some advantages of at least one embodiment of the syringe dispenser  100  include generating the therapeutic agent ozone on demand. Generating ozone on demand avoids aspects of inventory control to accurately account for the shelf-life of stored perishable therapeutic and medicinal agents. Since the syringe dispenser  100  is a self-contained apparatus, there is no contamination risk, or the contamination risk is minimized, associated with servicing and refilling syringes  110  and agents in the syringe dispenser  100 . Also, according to an embodiment, the syringe dispenser  100  may use commonly available and inexpensive raw materials such as ambient air and tap water. 
     Another advantage of at least one embodiment of the syringe dispenser  100  is that the syringe dispenser  100  is easily portable and may sit on a desktop or on the top of a laboratory bench in a medical facility, a therapy clinic, or a veterinary doctor&#39;s office. Because of its ease of portability and self-containment, the syringe dispenser  100  may be used on-site in hazardous and hostile environments to service, for example, construction and military personnel. The syringe dispenser  100  may also be easily leased or sold to treatment facilities. Alternatively, the syringe dispenser may be provided free-of-charge, with payments made for each unit dispensed from the syringe dispenser  100 . 
     Although the operations of the method(s) herein are shown and described in a particular order, the order of the operations of each method may be altered so that certain operations may be performed in an inverse order or so that certain operations may be performed, at least in part, concurrently with other operations. In another embodiment, instructions or sub-operations of distinct operations may be implemented in an intermittent and/or alternating manner. 
     Although specific embodiments of the invention have been described and illustrated, the invention is not to be limited to the specific forms or arrangements of parts so described and illustrated. The scope of the invention is to be defined by the claims appended hereto and their equivalents.