Abstract:
A respirator includes an external shell assembly, an internal shell assembly mounted inside the external shell assembly and communicating with outside of the external shell assembly through an intake passage, and a sound-absorbing member mounted inside the internal shell assembly and defining a channel therein. An air blower can be mounted inside the internal shell assembly for sucking the oxygen or air inputted externally into the internal shell assembly along the channel and then outputting it further to where it is required. The acoustic absorption of the sound-absorbing member and the covering of the internal and external shell assemblies can effectively lower the noise of the respirator, and the internal shell assembly can further focus the gas to enhance the efficiency of suction of the gas of the air blower and to reduce the heat generated by the air blower.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates generally to a medical apparatus, and more particularly, to a respirator. 
         [0003]    2. Description of the Related Art 
         [0004]    A conventional respirator is provided for the patient who suffers a particular disease, like SARS and H1N1, which disables his or her lungs from reaching sufficient gas exchange. The respirator is very common in the emergency ward or extensive care unit of the hospital. A household respirator is also available for the patient in need of long-term respiratory care at home. 
         [0005]    Most of the popular respirators are positive pressure ones, each of which is composed of a housing, an air blower mounted inside the housing, an intake pipeline connected with the housing, and a gas supply pipeline communicating with the air blower. The air blower can suck the oxygen or air entering the housing through the intake pipeline and then convey oxygen or air to the nasal or full-face mask that the patient wears through the gas supply pipeline and finally to the patient&#39;s lungs. 
         [0006]    However, the conventional respirator is defective because the air blower generates heat, which is not subject to dissipation, to heighten the temperature of the respirator, and makes much noise to not only interfere with the patient&#39;s rest but harass other people therearound. Besides, the conventional respirator can only provide oxygen or air without change to the gas source in communication with the intake pipeline; namely, the respirator cannot switch the gas type any time subject to the patent&#39;s need. In other words, the conventional respirator is still defective to need further improvement. 
       SUMMARY OF THE INVENTION 
       [0007]    The primary objective of the present invention is to provide a respirator, the working temperature of which is not subject to rise and the working noise of which is not much. 
         [0008]    The foregoing objective of the present invention is attained by the respirator composed of a housing and a sound-absorbing member. The housing includes an external shell assembly defining an external space outside itself, an internal shell assembly mounted inside the external shell and defining an internal space therein, and a first intake passage for communication between the external and internal spaces. The sound-absorbing member is mounted inside the internal space and defines a channel in communication with the internal space. The internal shell assembly can receive the oxygen or air inputted externally and the oxygen or air can flow along the channel of the sound-absorbing member and be pressurized and conveyed by the air blower out of the housing further to where it is required. The sound-absorbing member can absorb the noise made while the air blower sucks the gas inside the internal shell, and by the covering of the internal and external shell assemblies, the noise conveyed outside the housing can be greatly reduced, so the overall noise of the respirator is less than that of the prior art. In addition, the internal shell assembly can further focus the gas inside the housing to enhance the efficiency of suction of the gas of the air blower and to reduce the heat generated by the air blower, so the working temperature of the air blower is not subject to increase. 
         [0009]    The secondary objective of the present invention is to provide a respirator, which can switch gas type as per the patient&#39;s need. 
         [0010]    The foregoing objective of the present invention is attained by the respirator, the housing of which further comprises a second intake passage for communication between the internal and external spaces. The housing further comprises a rotary valve which is pivotable between a first position, at which the first intake passage is blocked from communicating with the internal space, and a second position, at which the second intake passage is blocked from communicating with the internal space. The first and second intake passages of the housing can communicate with an oxygen source and an air source separately. When the rotary valve is located at the first position, the second intake passage can have the air be inputted into the internal space for the air blower to suck and outputted to where it is required. Similarly, when the rotary valve is located at the second position, the respirator can output the oxygen inputted into the internal space through the first intake passage. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]      FIG. 1  is a partially exploded view of a preferred embodiment of the present invention, illustrating that the lower and upper shell pieces are separated from each other. 
           [0012]      FIG. 2  is a perspective view of the preferred embodiment of the present invention, from which the upper shell piece, the internal shell piece, and a plurality of the sound-absorbing members are removed for convenient illustration. 
           [0013]      FIG. 3  is an exploded view of parts of the preferred embodiment of the present invention. 
           [0014]      FIG. 4  is a sectional view of the preferred embodiment of the present invention, illustrating that the rotary valve is located at the first position. 
           [0015]      FIG. 5  is a top view of a part of the preferred embodiment of the present invention. 
           [0016]      FIG. 6  is a top view of parts of the preferred embodiment of the present invention. 
           [0017]      FIG. 7  is a bottom view of a part of the preferred embodiment of the present invention. 
           [0018]      FIG. 8  is a top view of parts of the preferred embodiment of the present invention. 
           [0019]      FIG. 9  is similar to  FIG. 4 , illustrating that the rotary valve is located at the second position. 
           [0020]      FIG. 10  is a schematic view of the preferred embodiment of the present invention, illustrating the filter cleanliness/turbidity identification system. 
           [0021]      FIG. 11  is a flow chart of the preferred embodiment of the present invention, illustrating the method of identifying the cleanliness/turbidity of the filter. 
       
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0022]    Referring to  FIGS. 1-3 , a respirator  10  constructed according a preferred embodiment of the present invention is composed of a housing  20 , a first sound-absorbing member  30 , a second sound-absorbing member  40 , and an air blower  50 . The detailed descriptions and operations of these elements as well as their interrelations are recited in the respective paragraphs as follows. 
         [0023]    The housing  20  includes a lower shell piece  21 , a rear shell piece  22 , an internal shell piece  23 , and an upper shell piece  24 . The lower shell piece  21  has a bottom  212 , as shown in  FIG. 4 , an external wall  214  integrally protruding upward from the bottom  212 , and an internal wall  216  integrally protruding upward from the bottom  212 . The rear shell piece  22  is mounted to a rear end portion of the lower shell piece  21  and connected with the external and internal walls  214  and  216 . The internal shell piece  23  is mounted above the lower shell piece  21  and connected with the internal wall  216  and the rear shell piece  22 . The upper shell piece  24  is mounted above the lower shell piece  21  and the internal shell piece  23  and connected with the external wall  214  and the rear shell piece  22 . The upper shell piece  24 , the bottom  212  of the lower shell piece  21 , the external wall  214 , and the rear shell piece  22  jointly constitute an external shell assembly  25  and define an external space outside the external shell assembly  25 . The internal shell piece  23 , the bottom  212  of the lower shell piece  21 , the internal wall  216 , and the rear shell piece  22  jointly constitute an internal shell assembly  26  and define an internal space inside the internal shell assembly  26 . Besides, the housing  20  further includes a first intake passage  27  and a second intake passage  28 , which are located at the rear shell piece  22 . The first intake passage  27  is provided with a first inner opening  272  and a first outer opening  274 ; the former faces the internal space of the internal shell assembly  26  and the latter faces the external space of the external shell assembly  25 . The second intake passage  28  is provided with a second inner opening  282  and a second outer opening  284 ; the former faces the internal space of the internal shell assembly  26  and the latter faces the external space of the external shell assembly  25 . In other words, the first and second intake passages  27  and  28  can allow communication between the internal and external spaces. 
         [0024]    Referring to  FIGS. 3-5 , each of the first and second sound-absorbing members  30  and  40  is made of foam which can absorb noise. The first sound-absorbing member  30  corresponds to the internal shell assembly  26  in profile and includes a curled channel  32  running therethrough. The channel  32  is provided with a first toothed portion  322  formed at one end of a center of the first sound-absorbing member  30 , and a second toothed portion  323  adjacent to the first toothed portion  322 . The second sound-absorbing member  40  is smaller than the first sound-absorbing member  30  in profile and has a through hole  42  running through a center thereof. Referring to  FIGS. 3  and  6 , the first and second sound-absorbing members  30  and  40  are mounted inside the internal space of the shell assembly  26 . In other words, the first sound-absorbing member  30  is mounted above the bottom  212  of the lower shell piece  21  and a shock-resistant bottom plate  61  is mounted between the first sound-absorbing member  30  and the bottom  212 . The second sound-absorbing member  40  is located above the first sound-absorbing member  30  and a shock-resistant intermediate plate  62  is mounted between the first and second sound-absorbing members  30  and  40 . The shock-resistant intermediate plate  62  is provided with an orifice  622 . The shock-resistant intermediate plate  62  covers a part of the channel  32 , so the channel  32  is provided with an entrance  324  and an exit  326 , both of which face upward. The first toothed portion  322  is located at the exit  326 . The second toothed portion  323  is adjacent to the exit  326 . Furthermore, a plurality of shock-resistant standing plates  63  are mounted between the first sound-absorbing member  30  and an inner side of the internal wall  216  of the lower shell piece  21 . 
         [0025]    Referring to  FIGS. 7-8 , the air blower  50  includes a case  52  and a motor  54  mounted inside the case  52 . The case  52  is provided with an inlet  56  and an outlet  58 . The motor  54  can make the gas be sucked into the case  52  through the inlet  56  and then exhaust, with a certain pressure, through the outlet  58 . The air blower  50  is mounted inside the internal space and makes its bottom be engaged with the through hole  42  to be mounted onto the shock-resistant intermediate plate  62 . In this way, the inlet  56  can communicate with the exit  326  through the orifice  622 . Besides, third sound-absorbing members  70  wrap the air blower  50  and are mounted to the second sound-absorbing member  40 . 
         [0026]    Referring to  FIGS. 4-8  again, while the respirator  10  of the present invention is being operated, the oxygen or air is inputted into the internal space through the first or second intake passage  27  or  28  and then enters the air blower  50  along the channel  32  through the entrance  324  subject to suction of the air blower  50 ; next, the air blower  50  provides a certain pressure to output the oxygen or air to the external space outside the housing  20  through an outtake passage  29  ( FIG. 1 ) from the outlet  58  and further to the patient&#39;s nasal or full-face mask to assist the patient in breathing. 
         [0027]    Specifically, the first and second intake passages  27  and  28  can provide the user of the respirator with two kinds of gases as required, i.e. oxygen and air. The housing  20  further includes a rotary valve  80  mounted close to the first and second inner openings  272  and  282 . The rotary valve  80  has a rotary shaft  82 , a first valve piece  84 , and a second valve piece  86 , the latter two of which integrally extend toward different directions. The rotary shaft  82  is pivoted between the lower and rear shell pieces  21  and  22  and can be driven for pivoting movement by a motor  88  ( FIG. 2 ) mounted to the rear shell piece  22 . When the rotary valve  80  pivots to a first position P 1  shown in  FIG. 4 , the first valve piece  84  fully blocks the first inner opening  272  to prevent the first intake passage  27  from communicating with the internal space; meanwhile, the second intake passage  28  communicates with the internal space, so the respirator  10  can supply the air to the user. When the rotary valve  80  pivots to a second position P 2  shown in  FIG. 9 , the second valve piece  86  fully blocks the second inner opening  282  to prevent the second intake passage  28  from communicating with the internal space; meanwhile, the first intake passage  27  communicates with the internal space, so the respirator  10  can supply oxygen to the user. 
         [0028]    In addition, a filter  90  can be further mounted between the second inner and outer openings  282  and  284  of the second intake passage  28 . The filter  90  is made of a material through which the gas can pass and which can filter impurities in the gas. For example, the filter  90  can be, but not limited to, a high efficiency particulate air (HEPA) filter. In light of this, when the rotary valve  80  is located at the first position P 1 , the air outside the housing  20  can be filtered by the filter  90  and then enter the internal space through the second intake passage  28  to allow the respirator  10  to supply fresh air. 
         [0029]    When the respirator  10  is being operated, the first sound-absorbing member  30  can absorb the noise generated by the air blower while it extracts the gas, especially the first and second toothed portions  322  and  323  of the channel  32 , which can reduce acoustic reflection, so the noise can be decreased. Besides, the second and third sound-absorbing members  40  and  70  can also absorb the noise of the motor  54  in operation and then by the covering the shock-resistant plates  61 - 63  and the external and internal shell assemblies  25  and  26 , the noise inside the internal space of the internal shell assembly  26  conveyed to the external space can be greatly reduced. Thus, less noise is the advantage of the respirator  10 . Furthermore, the housing  20  can concentrate the gas, which is to be pressurized and transmitted by the air blower  50 , on the internal shell assembly  26 , so the efficiency of the gas extraction of the air blower  50  is enhanced to decrease the thermal energy generated by the air blower  50  in such a way that the temperature of the respirator  10  is not subject to rise. 
         [0030]    It is to be noted that the primary effects of the present invention are less noise and less temperature rise and can be reached by that the external and internal shell assemblies  25  and  26  cover the noise inside the internal space, the channel  32  formed of the first sound-absorbing member  30  absorbs the noise of the gas extraction of the air blower  50 , and the internal shell assembly  26  concentrates the gas, which is to be pressurized and transmitted by the air blower  50 , to decrease the thermal energy of the air blower  50 . Under the circumstances, the second and third sound-absorbing members  40  and  70  and the shock-resistant plates  61 - 63  can be excluded from the respirator  10 . The present invention can reach another effect of switching gas type by that the first and second intake passages  27  and  28  supply two kinds of gases and the gases can be switched by the rotary valve  80 , so the housing  20  of the respirator  10  is not limited to the structure of the preferred embodiment as mentioned above as long as the housing  20  can have any space for saving gas and any two intake passages for communication with the space. Moreover, the second intake passage  28  can directly communicate with a device of supplying fresh air, like air cleaner, so the filter  90  can be excluded from the second intake passage  28 . 
         [0031]    However, if the filter  90  is mounted to the second intake passage  28 , the filter  90  will need cleaning or replacement after being used for a period of time. In light of this, the respirator  10  can further include a filter cleanliness/turbidity identification system for enabling the user to know when the filter  90  needs cleaning or replacement. As shown in  FIG. 10 , the system is composed of a suspended particle sensor  92 , a timer  94 , a display  96 , and a controller  98 . The suspended particle sensor  92  is mounted between the filter  90  and the second outer opening  284  for detecting concentration of suspended particles in the external air. The timer  94  can compute the working time of the air blower  50 , such as cumulative working fours, working hours for each booting of the air blower  50 , or cumulative hours of usage of the filter  90 . In this embodiment, the display  96  is mounted to the upper shell piece  24 , as shown in  FIG. 1 , and has three indicators indicative of “GOOD”, “AVERAGE”, and “BAD” for cleanliness/turbidity of the filter  90  separately. Interchangeably, the display  96  can be a screen capable of showing text or a device capable of giving off sound. The controller  98  is electrically connected with the suspended particle sensor  92 , the air blower  50 , the timer  94 , and the display  96  separately for receiving the data detected by the suspended particle sensor  92  and the timer  94  and for controlling the display  96  based on the data. 
         [0032]    As shown in  FIG. 11 , a method of identifying the cleanliness/turbidity of the filter can be carried out by the respirator  10  based on the aforesaid filter cleanliness/turbidity identification system, having the following steps. 
         [0033]    A) Detect the concentration of suspended particles in the external environment. As the concentration of the suspended particles is higher, the frequency of cleaning or replacing the filter  90  will be higher. 
         [0034]    B) Measure the wind speed of the air blower  50 . As the wind speed of the air blower  50  is higher, the air passing through the filter  90  within unit time will be more, so the frequency of cleaning or replacing the filter  90  will be higher. Besides, the wind speed of the air blower  50  is related to the wind pressure of the same, so measuring the wind speed of the air blower  50  can be replaced by measuring the wind pressure of the same. 
         [0035]    C) Calculate the working time of the air blower  50 . As the working hours of the air blower  50  are more to indicate that the filter  90  was used for longer time, it will be more necessary to clean or replace the filter  90 . According to different judgment conditions set, the timer can  94  can provide cumulative working hours of the air blower  50 , working hours of each booting, cumulative working hours of the filter  90 , etc. 
         [0036]    D) Identify the cleanliness/turbidity of the filter  90  pursuant to the concentration of the suspended particles in the external environment, the wind speed of the air blower  50 , and the working time of the air blower  50 . Because the results acquired from the steps A-C are closely related to the cleanliness/turbidity of the filter  90 , those results are transmitted to the controller  98  to be treated as judgment parameters and then computed together with a predetermined function to come up with the cleanliness/turbidity of the filter  90 . It is to be noted that the purposes of the steps A-C are for acquiring the aforesaid parameters and thus when the present invention is executed, the sequence of the steps A-C is not limited to that of the embodiment of the present invention. 
         [0037]    Last but not the least, the controller  98  can display the cleanliness/turbidity of the filter  90  on the display  96  for the user to decide whether to clean or replace the filter  90 . Alternatively, the controller  98  can identify the cleanliness/turbidity of the filter  90  and then decide whether it is necessary to clean or replace the filter  90  to generate a signal indicating that the filter  90  is too turbid to need cleaning or replacement and to display the signal on the display  96 . 
         [0038]    In conclusion, the respirator  10  can not only provide gas types that the user requires but provide filtered fresh air for the user, while the user selects the air, and enable the user to know whether the filter  90  should be replaced to further ensure the cleanliness of the air that the user breathes. 
         [0039]    Although the present invention has been described with respect to a specific preferred embodiment thereof, it is in no way limited to the specifics of the illustrated structures but changes and modifications may be made within the scope of the appended claims.