Abstract:
A blood pressure monitoring system that includes a compact housing that contains a pneumatic circuit that is removably attached to an inflatable cuff by a hoseless connector so that the cuff can be inflated and deflated to provide blood pressure readings that are detected by a pressure sensor. A controller is also contained in the housing which controls the circuit activities and records blood pressure related data. The controller is linked via a bidirectional communication system with a processor that is contained in a host station which programs the controller and collects and records blood pressure related data. The communication system also allows the monitoring system to communicate over a wider network with other remote stations.

Description:
FIELD OF THE INVENTION 
       [0001]    This invention relates to a blood pressure device and, in particular, to a blood pressure system that provides a flexible and low cost platform for automatically performing a non-invasive procedure without the need of external interconnections such as pneumatic tubes and electrical wiring. 
       BACKGROUND OF THE INVENTION 
       [0002]    Non-invasive blood pressure devices generally utilize an inflatable cuff to measure a patients blood pressure. The cuff is affixed to a limb over an artery and is then inflated to constrict the flow of blood through the artery. Blood passing through the constrained vessel produces changes in the cuff pressure which can be measured by a pressure sensor to give an indication of the condition of the patients heart. Two pressures of specific interest are the systolic pressure and the diastolic pressure. Systolic pressure is the maximum arterial pressure produced during the contraction of the left ventricle of the heart. The diastolic pressure is the minimum pressure that is produced during the relaxation period during which the ventricles are filling with blood. Using the well known oscillometric method, the blood pressure cuff is initially inflated to a pressure that is higher than the expected systolic reading and the cuff is then deflated to a pressure that is lower than that of the expected diastolic reading. As the cuff pressure falls to a pressure near the systolic pressure, the pressure sensor that monitors the arterial pressure detects oscillations that are superimposed on the falling cuff pressure. Correspondingly, when the cuff pressure falls below the diastolic pressure the oscillations are no longer detected. These two events can be recorded by the sensor to provide valuable information relating to the patients heart as well as the patients heart rate. 
         [0003]    Blood pressure devices are presently available that will automatically provide accurate blood pressure readings and, to a large extent, eliminate or minimize human error. These prior art devices, however, tend to be rather large and have external tubing and electrical wires interconnect the various components of the system. The monitoring system generally is located at a fixed location and the patient must come to the system at that specific location. Some automatic systems, particularly those found in health care facilities where many of the patients are not ambulatory, are mounted upon mobile carriers which permit the system to be wheeled between patient locations. However, because of the number of tubes and wire involved, the transporting of these systems can be difficult and the tubes and wires tend to become entangled with other fixtures and furniture. In addition, these systems usually contain a single cuff that is exchanged between patients and cross contamination is thus an ever present concern. 
       SUMMARY OF THE INVENTION 
       [0004]    It is a primary object of the present invention to improve non-invasive blood pressure devices and, in particular, monitors that are capable of automatically taking a patients blood pressure. 
         [0005]    A further object of the present invention is to eliminate the need of sharing a common blood pressure cuff between a number of patients. 
         [0006]    Another object of the present invention is to eliminate the need for loose pneumatic and electrical lines running between the components of an automatic blood pressure monitor. 
         [0007]    These and other objects of the current invention are attained by a blood pressure device that includes a compact housing that contains a pneumatic circuit that is attached to an inflatable cuff by a hoseless releasable connection so that the cuff can be automatically inflated and deflated to provide blood pressure readings that are detected by a pressure sensor located in the housing. A controller is also contained in the housing which controls the activity of the pneumatic circuit and which is capable of recording and storing blood pressure reading. The controller is linked via a wireless bi-directional communication system with a processor contained within a host station which programs the controller and processes blood pressure data generated by the pressure sensor. The communication system further enables the host station to communicate with other remote stations. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    For a better understanding of these and other objects of the invention reference will be made to the following detailed description of the invention which is to be read in conjunction with the accompanying drawings, wherein: 
           [0009]      FIG. 1  is a perspective view illustrating a non-invasive blood pressure cuff and a compact housing contains a number of components of the present blood pressure monitoring system wherein the monitor housing is shown separated from the cuff prior to the two units being connected. 
           [0010]      FIG. 2  is a further perspective view illustrating the bottom face of the housing and showing in further detail one member of a hoseless connection for co-joining the housing and the cuff; 
           [0011]      FIG. 3  is an enlarged perspective view of the compact housing shown in  FIG. 1  with the top cover being removed as well as a printed circuited board which is shown inverted and to the left of the open bay of the housing; and 
           [0012]      FIG. 4  is a flow diagram schematically illustrating the relation component parts of the present blood pressure monitoring system. 
       
    
    
     DETAILED DESCRIPTION 
       [0013]    A blood pressure system, generally referenced  10 , that embodies the present invention is shown schematically in  FIG. 4 . The system  10  includes a small compact housing  12  that contains a three element pneumatic circuit  13 . The pneumatic circuit includes a pump  15 , an exhaust valve  16  and a pressure sensor  17 . The elements of the pneumatic circuit are all connected to a common pneumatic line  19  which, in turn, is coupled to one part  50  of a two piece connector that is generally referenced  20 . As will be explained in further detail below, the other part of the connector  53  is attached to a non-invasive blood pressure cuff  23 . 
         [0014]    Also contained in the housing  12  is a controller  25  which is a microprocessor that can be programmed to control the pump and valve to inflate and deflate the cuff and to receive pressure related data from the pressure sensor. The controller is coupled to a wireless bi-directional communication unit  26  which links the controller to a remote host station that is generally referenced  30 . A rechargeable battery  27  is located within the housing  12  and is arranged to power the system components situated within the housing. 
         [0015]    The host station contains a second bi-directional communication unit  31  that is capable of linking the controller to a processor  33  that is contained within the host station. The processor is arranged to program the controller so as to carry out a desired blood pressure monitoring cycle via the pneumatic circuit  13 . The processor also includes a storage unit  35  for storing blood pressure related data as well as patient related information and the time and date of various occurrences. 
         [0016]    A display unit  37  is also contained within the host station for displaying real time blood pressure related data from the processor or historical patient related data that can be recalled from the storage unit  35 . Stored or real time data can also be broadcast by bi-directional communication unit  31  to other remote stations such as a central control station  36  for further evaluation or processing of related data. 
         [0017]    The compact housing  12 , because of the limited number of compartments that are contained therein, can be extremely small in size and light of weight thus allowing it to be directly connected to and carried upon a blood pressure cuff. In addition, the connector  20 , through which the pneumatic circuit communicates with a cuff, is a releasable device and accordingly, a single housing can be used in association with a number of cuffs within a heath care facility, physician&#39;s office, or the like. In this type of location, each patient can be issued his or her cuff upon entering the facility and the attendant health care worker can simply connect the monitor housing to the individual cuffs when taking blood pressure readings. As can be seen, all readings will then be sent to a central host station for processing, evaluation and storage. This procedure will reduce the risk of cross contamination that is normally present in facilities where a single cuff is used continuously to take the pressure readings of a large number of patients. 
         [0018]    The present monitoring system can also be used in physicians offices where the patients typically must wait to be seen in a waiting area. Here, the waiting patients can be issued cuffs and a single monitor housing exchanged between patients to provide blood pressure data to the host station that will be available to the examining physician immediately upon seeing a patient. This procedure can save many hours of each day both of the physicians time and the patients time in a typical office setting. 
         [0019]    Turning now to  FIGS. 1-3 , there is illustrated in further detail, a monitor housing  10 . As noted above, the housing is compact and is about 4.0″ high, 2.5″ wide and has a depth of about 1.0″. This coupled with the light weight of the limited number of components that are contained within the housing, permits the housing to be easily and safely attached to the cuff by means of the two piece connector  20 . As illustrated in  FIGS. 2 and 3 , the connector  20  includes a female member  50  that is secured to the back panel  51  of the monitor housing  12 . The female member is adapted to mate with a male member  53  that is secured to the sleeve  54  of a non-invasive blood pressure cuff, as for example cuff  23  ( FIG. 4 ). As will be explained in further detail below, the male member is capable of being snap fitted into the female member to establish a releasable leak tight joint between the co-joined members. 
         [0020]    As illustrated in  FIG. 2  the female member  50  includes a cylindrical or tubular sleeve  55  that opens through the back panel of the housing into a flow channel  56  that contains a pair of entry ports  57 - 57  that are in fluid flow communication with the pneumatic circuit  13  ( FIG. 4 ) via the previously noted common flow line  19 . A circular groove  58  is formed in the interior wall of the tubular sleeve so that the sleeve and the groove share a common axial centerline  59 . 
         [0021]    In  FIG. 1 , the housing  12  is shown positioned directly over the sleeve  54  of cuff  23  just prior to closure o the two piece connector  20 . At this time, the male member  53  of the connector is axially aligned with the female member of the connector along a common center line  59 . The male member  53  contains a cylindrical body  63  that extends upwardly from a grommet that secures the body to the cuff sleeve. A circular bead  64  surrounds the body of the male member which snap fits into the circular groove in the female at closure. One or both of the connector members may be fabricated of a resilient material such that the joint formed between the two members at closure is leak tight but flexible enough to allow the housing to be rotated about the common axis  59  without breaking the joint. At closure, the cylindrical opening  65  in the male member is in direct fluid flow communication with the pneumatic circuit via flow ports  57 - 57  and flow line  19 . 
         [0022]      FIG. 3  shows the lower portion or pan  70  of the housing with the cover and the printed circuit board  71  removed from the pan so that most of the components that are contained in the housing can be more clearly viewed. The backside of the female connector  50  can be seen in the mid-section of the pan. The two flow ports  57  and  57  are shown extending to either side of the connector body. The tubing for connecting the ports to the pneumatic circuit have been removed for the sake of clarity. Immediately beneath the connector is the pump  15  and the exhaust valve  16 . Above the connector  50  is the rechargeable battery  27 . The communication system transmitter  75  and receiver  76  are mounted upon the backside of the circuit board  71  along with the controller  25  and the pressure sensor  17 . 
         [0023]    As can be seen, the pneumatic components and related drive and electrical components of the present invention are all tightly packaged inside the housing to provide a compact unit that can be suspended from a blood pressure cuff. As should be evident from the disclosure above, the present system has eliminated the need for troublesome electrical and pneumatic lines running between various components of the system and reduces the danger of cross contamination between patients that are forced to share a common blood pressure cuff. 
         [0024]    While the invention has been described with reference to preferred embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof to adapt to particular situations without departing from the scope of the invention. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope and spirit of the appended claims.