Claims:I CLAIM
1. A system for conditioning and sterilizing air arranged on a sidewall of an enclosure having protected environment, said system comprising:
a first chamber having an air inlet;
an air passage in operative communication with said first chamber for conveying the air;
a second chamber having an air outlet, said second chamber being in operative communication with said air passage for receiving the air to be purified;
wherein, said system being ductless and operated at a positive pressure, in which:
said first chamber comprises at least one flow control means to control the inlet air flow, a first air diverter to direct the inlet air flow in a upward direction, at least two primary washable filters of 5 µm to filter the inlet air to obtain a filtered air stream, at least one ozone producing UV lamp to further treat said filtered and purified air stream; and at least one air heating system for getting the desired working temperature inside the enclosure between 18 -24OC.
said second chamber receiving said filtered and purified air stream from said first chamber through said air passage, , at least two secondary filter to filter said treated air stream, and a second air diverter to direct the outlet air flow of said treated air stream in a upward direction through said air outlet; and
said air inlet and said air outlet being at least relatively separated by means of said air passage..
2. The system as claimed in claim 1, wherein said secondary filters are HEPA filter of 0.3 micron and microvee filter 0f 3 micron.

3. The system as claimed in claim 1, wherein said first chamber comprises an expansion valve and filter for ac gas.

4. The system as claimed in claim 1, wherein said first chamber comprises a washable pre-filter of 5 micron at said air inlet.

5. The system as claimed in claim 1, wherein said flow control means comprises an auxiliary fan speed regulator. .

6. The system as claimed in claim 1, wherein said first chamber comprises a third air diverter to direct air flow through said first chamber to said second chamber.

7. The system as claimed in claim 1, wherein said system comprises of acoustic panels to reduce noise.

8. The system as claimed in claim 1, wherein said first chamber comprises an air heating system for controlling the relative humidity and for climate control.

9. The system as claimed in claim 1, wherein said fresh air flow control damper means are adapted to take about 12 - 16% of fresh air component per cycle.

10. The system as claimed in claim 1, wherein said system is adapted to provide more than 25 air changes per hour.
11. The system as claimed in claim 1, wherein said system comprises means for displaying and controlling at least one parameter selected from temperature, humidity, air flow, and the like.

12. A laminar air flow system, said system comprising:
a pre-filter positioned in operative communication with an air inlet to filter the incoming air;
an air purifying device including at least one HEPA filter being positioned in operative communication with said pre-filter to receive the pre-filtered air therefrom and to provide purified air; and
an air flow means for providing a laminar air flow of the purified air from said air purifying device so as to define an air tent over an operating or treating bed; and
wherein, said laminar air flow system being ductless.

13. The system as claimed in claim 12, wherein said air purifying device comprises a main filter and atleast one washable filter of 3 µm arranged lateral to said main filter.

14. A system for conditioning and sterilizing air in an enclosure having protected environment, said system comprising:
a first apparatus AHU without duct arranged on a sidewall about the height of an operating or treating bed, including:
a first chamber having an air inlet;
an air passage in operative communication with said first chamber for conveying the air;
an expansion valve with filter for AC gas;
a second chamber having an air outlet, said second chamber being in operative communication with said air passage for receiving the air to be purified;
wherein, said system being ductless and operated at a positive pressure, in which:
said first chamber comprises at least one fresh air flow control damper means to control the inlet air flow, a first air diverter to direct the inlet air flow in a upward direction, at least two primary filters to filter the inlet air to obtain a filtered air stream, at least one ozone producing UV lamp to further treat said filtered and purified air stream, and at least one cooling coil to cool the filtered and purified air stream thereof;
said second chamber receiving said filtered and purified air stream from said first chamber through said air passage, , at least two secondary filter to filter said treated air stream, and a second air diverter to direct the outlet air flow of said treated air stream in a upward direction through said air outlet; and
said air inlet and said air outlet being at least relatively separated by means of said air passage; and
a second apparatus arranged on a ceiling, said second apparatus being ductless, and including:
a pre-filter positioned in operative communication with an air inlet for filtering the incoming air;
an air purifying device including at least one HEPA filter being positioned in operative communication with said pre-filter for receiving the pre-filtered air therefrom and to provide purified air; and
an air flow means for providing a laminar air flow of the purified air from said air purifying device so as to define an air tent over the operating or treating bed.

15. The system as claimed in claim 14, wherein said secondary filters are a HEPA filter of 0.3 micron and microvee filters of 3 micron.

16. The system as claimed in claim 14, wherein said first chamber comprises an expansion valve with filter for AC gas..

17. The system as claimed in claim 14, wherein said first chamber comprises a washable pre-filter of 5 microns at said air inlet.

18. The system as claimed in claim 14, wherein said flow control means comprises an auxiliary fan speed regulator.

19. The system as claimed in claim 14, wherein said first chamber comprises a third air diverter to direct air flow through said first chamber to said second chamber.

20. The system as claimed in claim 14, wherein said system comprises of acoustic panels to reduce noise.

21. The system as claimed in claim 14, wherein said fresh air flow control damper means are adapted to take about 12 - 16% of fresh air component per cycle.

22. The system as claimed in claim 14, wherein said first apparatus is adapted to provide at least 25 air changes per hour.
23. The system as claimed in claim 14, wherein said second chamber comprises an air heating system for controlling the relative humidity and for climate control

24. The system as claimed in claim 14, wherein said air purifying device comprises a main filter and more than one HEPA filter arranged lateral to said main filter.

25. The system as claimed in claim 14, wherein said system comprises means for displaying and controlling at least one parameter selected from temperature, humidity, air flow, and the like.

26. The circulation air flow pattern with system in comprises of,
air comes inside the operating room or theatre through HEPA filters of the first apparatus 100 (AHU without duct);
air gets diverted towards second apparatus 200 (Laminar Air Flow system) through pre-filters as it having backward curve fans or auxiliary fans for drawing the air backward;
air further passes through HEPA filter from second apparatus 200 and air flow prepares an air tent on Operation table 301.
, Description:FIELD OF INVENTION

The present invention relates to a system for conditioning and sterilizing air.

More particularly, the present invention relates to a system for conditioning and sterilizing of operating rooms or theatres, burn treatment units, intensive care units, maternity wards, clinical environments and other critical premises where there are demands for purified or sterilized air by supply of air treated in an air conditioning system.

BACKGROUND & PRIOR ART
An efficient air purification cum air conditioning system is of utmost importance in critical care units of hospitals, operation theatres, theater sterile supply units and other clinical environments, where the environment must be kept free of bacteria, germs, microbes, fungus, virus and dust, and the humidity and the temperature must be strictly controlled. Any compromise thereof can result in the spreading of infectious diseases by the viruses and bacteria in the air.

Pneumonia, scarlet fever, mumps, rubella, meningitis, tuberculosis and chicken pox, are some diseases that are typically transmitted through droplets expelled as an infected person breathes, speaks, coughs or sneezes. These diseases are carried through the air by particulates, like dust particles, which particles hang in the air and travel through ventilation systems over considerable distances. At present the air purification is done through HEPA filters, however the viral, fungal and bacterial outbreaks have emphasized on the importance of better and more efficient systems and methods of air purification.

In a conventional operating theatre equipped with an air-conditioning system, the air is supplied at a controlled temperature and relative humidity through filters and is introduced into the operating theatre by diffusers located either in the walls or in the ceiling of the theatre. Tests have shown that the clean incoming air can be contaminated by entrained ambient air with the result that the organisms present on the floor of the operating theatre, as well as those emitted by the bodies of the surgical team and the patient, are circulated around the operating area with a consequent risk of infection.

Consequently, a number of air supply systems have been developed which provide a downward flow of air at a speed of about 0.5 m/sec. to oppose convection currents. These supply systems, however, have a variety of limitations such as those involved in providing enclosures within which downward airflow patterns have already been established.

Also, laminar airflow systems are desirable when deep invasive surgery is performed as such systems can ensure a particularly high level of air purity within a designated enclosed air space (e.g. in the region of the patient on the operating table). In effect, such laminar air flow systems cause the entire body of air within that space to move with uniform velocity in a single downwards direction along parallel flow lines. Turbulence within the air space is thus greatly reduced so that any particles of impurities are flushed out of the air space. National Accreditation Board for Hospitals & Healthcare (NABH) recommends Class II air particulate count i.e. > 10-100 particles per sq.ft. in Operation theaters. However, present air conditioning system provides Class I air particulate count i.e. > 1-10 particles per sq.ft.

However, traditional laminar air flow systems can be expensive to run as they require constant operation of high speed fans as the system requires twice air conditioning. Also, as the air flow is directed towards the operation table, it can cause discomfort, cold and shivering to the patient. Also, the filters which are provided to purify the air in these systems have a limited effective lifetime and require regular replacement. Furthermore, the dust and microbes may accumulate in the ducting of the laminar air flow system and over a very short period multiply and grow within the ducting and the filter unit and be carried along with the air into the operation theatre.

PCT Application WO2014106738 relates to a prior art air flow system for an operating theatre and a method of generating laminar air flow in an operating theatre. The air flow system comprises at least one laminar air flow fan operable to provide laminar air flow into an operating theatre from a ceiling and a laminar flow hood. The laminar flow hood is configured to guide the laminar air flow into the operating theatre. The laminar flow hood is configured to compress the laminar air flow so as to exploit the Bernoulli Effect, resulting in the laminar air flow increasing in velocity after exiting the laminar flow hood. The system, however, does not teach sterilization of the air.

The present invention is directed to a system for conditioning and sterilizing air for operation theatres and critical care units, which at least partially overcomes at least one of the above-mentioned deficiencies in the prior art.

SUMMARY OF THE INVENTION
Accordingly, an aspect of the present invention is directed to a system for conditioning and sterilizing air for an enclosure such as operation theatres, burn treatment units, critical care units, and the like, which require a protected environment.

An object of the present invention is to provide a system for conditioning and sterilizing air which is ductless, eliminates bacteria, dust, microbes, fungi, virus, etc., from the air, while conditioning the air to provide optimum temperature and relative humidity in the enclosure.

Another object of the present invention is to provide a system for conditioning and sterilizing air which provides 25 air changes per hour and fresh air component per air cycle to minimize the biological load in the enclosure.

An additional object of the present invention is to provide a system for conditioning and sterilizing air which provides a reduction in the particulate matter count to Class I i.e. >1-10 at the center of the enclosure, and to Class II i.e. >10- 100 at the corners and edges of the enclosure.

Yet another object of the present invention is to provide a system for conditioning and sterilizing air which provides for controlling the air temperature, humidity and level of purification, noise reduction, and which further provides a climate control system for temperature regulation during winters.

One more object of the present invention is to provide a system for conditioning and sterilizing air which is easy to maintain.

Other aspects, objects and advantages of the present invention will be apparent from the following description.

According to an aspect of the present invention, there is disclosed a system for conditioning and sterilizing air arranged on a sidewall of an enclosure having protected environment, said system comprising:
a first chamber having an air inlet;
an air passage in operative communication with said first chamber for conveying the air;
a second chamber having an air outlet, said second chamber being in operative communication with said air passage for receiving the air to be purified;
wherein, said system being ductless and operated at a positive pressure, in which:
said first chamber comprises at least one flow control means to control the inlet air flow, a first air diverter to direct the inlet air flow in a upward direction, at least two primary filter to filter the inlet air to obtain a filtered air stream, at least one UV ozone producing lamp to purify the filtered air stream, and at least one cooling coil to cool the filtered and purified air stream thereof; the first chamber may comprise an air heating system which further acts as humidity control means for controlling the
relative humidity and climate control when room temperature is less than the desired temperature.
said second chamber receiving said filtered and purified air stream from said first chamber through said air passage, said second chamber comprising at least two secondary filter to filter said treated air stream, and a second air diverter to direct the outlet air flow of said treated air stream in a upward direction through said air outlet; and
said air inlet and said air outlet being at least relatively separated by means of said air passage.
.
Typically, in accordance with the present invention, said secondary filters are HEPA filter of 0.3 microns and microvee filter of 3 microns. The first chamber may comprise an expansion valve with filter. The expansion valve provides best cooling temperature. The said first chamber filled with air conditioning gas with vacuum the copper/discharge line upto 100 micron. Further, the first chamber may comprise a pre-filter at said air inlet. Preferably, the flow control means comprise a volume control damper. Additionally, the first chamber comprises a third air diverter to direct air flow through said first chamber to said second chamber. Furthermore, the system is laminated with acoustic panels to reduce noise. The - first chamber may comprise an air heating system which further acts as humidity control means for controlling the relative humidity and climate control when room temperature is less than the desired temperature.

Preferably, the flow control means comprise a volume control damper. More preferably, the flow control means are adapted to take about 12 - 16% of fresh air component per cycle. Additionally, said system is adapted to provide more than 25 air changes per hour.

The system may comprise means for displaying and controlling at least one parameter selected from temperature, humidity, air flow, and the like.

According to another aspect of the present invention, there is disclosed a laminar air flow system, said system comprising:
a pre-filter positioned in operative communication with an air inlet for filtering the incoming air;
an air purifying device including at least one HEPA filter being positioned in operative communication with said pre-filter for receiving the pre-filtered air therefrom and to provide purified air; and
an air flow means for providing a laminar air flow of the purified air from said air purifying device so as to define an air tent over an operating or treating bed; and
wherein, said laminar air flow system being ductless.

Preferably, said air purifying device comprises a main filter and more than one filters arranged lateral to said main filter.

According to yet another aspect of the present invention, there is disclosed a system for conditioning and sterilizing air in an enclosure having protected environment, said system comprising:
a first apparatus arranged on a sidewall about the height of an operating or treating bed, including:
a first chamber having an air inlet;
an air passage in operative communication with said first chamber for conveying the air;
a second chamber having an air outlet, said second chamber being in operative communication with said air passage for receiving the air to be purified;
wherein, said system being ductless and operated at a positive pressure, in which:
said first chamber comprises at least one flow control means to control the inlet air flow, a first air diverter to direct the inlet air flow in a upward direction, at least two primary filter to filter the inlet air to obtain a filtered air stream, at least one UV ozone producing lamp for not to allow growth of fungus and bacteria’s on cooling coil, and at least one cooling coil to cool the filtered and purified air stream thereof; The said first chamber may comprise an air heating system which further acts as humidity control means for controlling the relative humidity and climate control when room temperature is less than the desired temperature.
said second chamber receiving said filtered and purified air stream from said first chamber through said air passage, said second chamber comprisingat least two secondary filter to filter said treated air stream, and a second air diverter to direct the outlet air flow of said treated air stream in a upward direction through said air outlet; and
said air inlet and said air outlet being at least relatively separated by means of said air passage; and
a second apparatus arranged on a ceiling, said second apparatus being ductless, and including:
a pre-filter positioned in operative communication with an air inlet for filtering the incoming air;
an air purifying device including at least one HEPA filter being positioned in operative communication with said pre-filter for receiving the pre-filtered air there from and to provide purified air; and
an air flow means for providing a laminar air flow of the purified air from said air purifying device so as to define an air tent over the operating or treating bed.

Typically, said secondary filters are a HEPA filter of 0.3 microns and microvee filter of 3 microns. The first chamber may comprise an expansion valve with filter for AC gas. Further, the first chamber may comprise a pre-filter at said air inlet. Preferably, the flow control means comprise a volume control damper. Additionally, the first chamber comprises a third air diverter to direct air flow through said first chamber to said second chamber. Furthermore, the system is laminated with acoustic panels to reduce noise. The first chamber may comprise a air heating system which further acts as a humidity control means for controlling the relative humidity and and climate control system.

According to yet another aspect of the present invention, there is disclosed a circulation pattern of air flow by said system, said circulation pattern comprising-
? Air comes inside the operating room or theatre through HEPA filters of the first apparatus (AHU without duct);
? Further air gets diverted towards second apparatus (Laminar Air Flow system) through pre-filters as it having backward curve fans or auxiliary fans for drawing the air backward;
? The air further passes through HEPA filter from second apparatus and air flow prepares an air tent on Operation table which is called as laminar air flow system or uni-directional air flow.
Generally, said flow control means comprise a volume control damper. The flow control means can be adapted to take about 12 - 16% of fresh air component per cycle.

Typically, said first apparatus is adapted to provide at least 25 air changes per hour. Preferably, said air purifying device comprises a main filter and more than one auxiliary fan arranged lateral to said main filter.

Additionally, said system may comprise means for displaying and controlling at least one parameter selected from temperature, humidity, air flow, and the like.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
The present invention will be described here below with reference to the following drawings, in which,

FIGURES 1A & 1B illustrate a schematic of the preferred embodiment of the system for conditioning and sterilizing air in accordance to the present invention;

FIGURES 2A & 2B illustrate a schematic of the preferred embodiment of the laminar air flow system in accordance to the present invention.

FIGURE 3 illustrate a schematic of the preferred embodiment of the circulation pattern of air flow with the system in accordance to the present invention.

DETAILED DESCRIPTION OF THE INVENTION
The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting examples in the following description. The examples used herein are intended merely to facilitate an understanding of the ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.

Figures 1A & 1B of the accompanying drawings illustrate a schematic of the preferred embodiment of the system for conditioning and sterilizing air in accordance with the present invention, the system being generally referenced in the figs. by the numeral 100 is Air Handling Unit (AHU). Figure 1A shows a front view of the embodiment 100. The embodiment 100 is a ductless system. Also, the system is operated at positive pressure, preventing outside air entering inside the operation theater from doors opening. The front view shows the AC on/off 102, the temperature display 104, the ozone on/off 106 and the sound regulator 108.
Figure 1B shows a sectional view of the embodiment 100. The embodiment 100 shows a lower first chamber and an upper second chamber positioned operatively above the first chamber. The first chamber has an inlet for air (indicated by arrows ‘A’). A first air diverter 110 is provided at the inlet for causing the air to enter in an upward direction. A pre-filter 112 of 5 microns is provided proximal to the inlet for filtering the inlet air stream. A primary filter of 5 microns and air damper 116 is provided in the first chamber. The volume control damper is provided to control the air flow rate into the system. The volume control damper is adapted to take about 12 to 16 %, preferably 16%, fresh air per air cycle so as to minimize the biological load in the enclosure. The inlet air is filtered through the pre-filter 112 and the primary filter for removing the particulate matter. The first chamber also comprises at least one ozone- producing UV lamp 118 for purifying and sterilizing the inlet air stream. The purified and sterilized air stream is then cooled by means of cooling coils 114 provided in the first chamber. The cooled and purified air stream is then conveyed through one or more expansion valves and filter 122 for filtration of air-conditioning gas. The cooled and purified air stream is directed to the second chamber by means of a third air diverter 120. The third air diverter 120 is a curved aluminum sheet with acoustic for directing the air flow upwards. An air passage clearly separates the first chamber and the second chamber. A drain pipe 126 is provided for draining the water produced during refrigeration. An air heating system 128 is provided after cooling coil which further acts as humidity control means for controlling the relative humidity and climate control when room temperature is less than the desired temperature.
One or more acoustic panels 124 are embedded within AHU system 100 provided for reducing the noise from the system. The first chamber also comprises an air heating system which further acts as humidity control means 127 for controlling the relative humidity of the outgoing air stream and climate control system

The second chamber comprises. The treated air is then conveyed through a secondary filter 130 is 3 microns washable filter and a HEPA filter is 0.3 microns paper filter 132 before exiting at the air outlet. The gap between the two filters is maintained around 1 foot. The air flow direction is indicated by arrows ‘A’. The outgoing air stream is conveyed through a second air diverter 134 to direct the outgoing air stream upwards, to prevent any mix-up between the incoming and the outgoing air stream. Air heating system is provided in between first chamber and second chamber above cooling coil for climate control and humidity control. The first chamber and the second chamber are covered by an acoustic panel, as shown in the front view Fig. 1A. The system comprises means for displaying and controlling at least one parameter selected from temperature, humidity, air flow, and the like. The system is adapted to provide at least 25 air changes per hour.

The embodiment 100 is a ductless system. Also, the system is operated at positive pressure, preventing any outside air from entering therein. The embodiment 100 provides conditioning and sterilizing of air, wherein the system is arranged on a sidewall of the enclosure where a protected environment is to be maintained.
Figures 2A & 2B illustrate the preferred embodiments of the laminar air flow system in accordance with the present invention. Further Figure 2A represents first part of the laminar air flow system and Figure 2B represents second part of the laminar air flow system, which collectively forms a whole laminar air flow system. The system being generally referenced by the numeral 200. The laminar air flow system of present invention is ductless. The laminar air flow system 200 is arranged on the ceiling, generally substantively above the operation table or treatment bed. The system 200 shown in Fig. 2A comprises a pre-filter 206 and a primary HEPA filter 202. The system 200 further comprises a fan speed regulator 208, a temperature and humidity display 210 and a HEPA filter condition display 212 (shown in the Fig. 2A). The system 200 is laminated by acoustic panels 204 to reduce noise from the system.

The system 200 shown in Fig. 2B comprises a pre-filter 220 in a first chamber 214. The pre-filter 220 is provided in operative communication with the air inlet. The pre-filtered air from the first chamber 214 is conveyed to a second chamber 216 through the air passage 218. The air passage 218 distinctly separates the first chamber 214 and the second chamber 216.

The second chamber 216 comprises an air purifying device including a main HEPA filter 222 and two HEPA filters 224 & 226 arranged lateral to the main filter 222. The said two filters 224 & 226 are separated by a recess 228 for mounting surgical OT light. The system 200 comprises an air flow means (not shown in figure) for providing a laminar air flow of the purified air from the air purifying device so as to define an air tent over an operating table or treating bed. The system 200 is attached to the ceiling by means of the attachment means 230 for mounting the laminar air flow system. The filters of the system 200 are adapted to be removed and cleaned, thereby making the maintenance of the system easy and economical.

Another preferred embodiment of the present invention may comprise a first apparatus comprising the system 100 for conditioning and sterilizing air provided together with a second apparatus comprising the laminar air flow system 200. The first apparatus is arranged on a sidewall of the enclosure, while the second apparatus is arranged on the ceiling. The first apparatus is preferably arranged about the height of the operating table or treating bed. The air from the second apparatus which forms a tent over the operation table or treatment bed, is absorbed by the first apparatus which purifies and cools the air before returning it into the enclosure. The first apparatus is adapted to take 12 – 16%, preferably 16%, fresh air component per cycle. The system provides at least 25 air changes per hour.

FIGURE 3 illustrate the preferred embodiments of the circulation air flow pattern with system in accordance with the present invention. Wherein, air comes inside the operating room or theatre through HEPA filters of the first apparatus 100 (AHU without duct); Further air gets diverted towards second apparatus 200 (Laminar Air Flow system) through pre-filters as it having backward curve fans or auxiliary fans for drawing the air backward The air further passes through HEPA filter from second apparatus 200 and air flow prepares an air tent on Operation table 301 which is called as laminar air flow system or uni-directional air flow.

EXPERIMENT-
On below laminar air flow at OT table level air particle counts measured with present system and plenum system.
Particles per cubic feet NABH Recommended Present System Plenum System
Class II
i.e. >10-100 Class I
i.e.>1-10 Class IV
i.e. >1000-10000

TECHNICAL ADVANTAGES OVER PRIOR ART

• Regular maintenance of the system from inside the operation theater can be maintained by non technical person by just cleaning of two washable filters once in fifteen days; which is not practically possible with ducted system;

• Secondary filter which are microvee filter of 3 microns of AHU extends the HEPA filter life; absorb air cutting sound, better air quality, and maintenance once in three months.

• HEPA filter life is two years in present system and replacement is easy in present system. In ducted system HEPA has to change once in six months and every time ducts to be cleaned with robotic duct cleaning otherwise HEPA filter will get chocked within a week and purpose of changing filter will not be solved;

• Recurring cost of maintenance of present system is very less i.e. once in two years changing the HEPA filter;
• The air gets filtered two times through HEPA filter before coming on Operation table, hence the air particle count of operation theater with present system is Class I i.e. >1-10 particles per sq. ft.

• Particle count of the present system below the laminar air flow system on OT table level is class I i.e. >1-10 and OT room class is between class III i.e. >100-1000. While other ducted ac systems gives class IV i.e. >1000-10000 on table and class V i.e. >10000-100000 in room;

• Ozone UV light lamp in first chamber does not allow fungus, bacterial growth on cooling coil;

• Climate control system maintains the inside temperature when the outer temperature is lesser than the required temperature.

Embodiment of the present invention is applicable over a wide number of uses and other embodiments may be developed beyond the embodiment discussed heretofore. Only the most preferred embodiments and their uses have been described herein for purpose of example, illustrating the advantages over the prior art obtained through the present invention; the invention is not limited to these specific embodiments or their specified uses. Thus, the forms of the invention described herein are to be taken as illustrative only and other embodiments may be selected without departing from the scope of the present invention. It should also be understood that additional changes and modifications, within the scope of the invention, will be apparent to one skilled in the art and that various modifications to the construction described herein may fall within the scope of the invention.