Abstract:
A method for measuring blood pressure and pulse rate with a pump-less mechanical compression apparatus, wherein the pump-less mechanical compression apparatus comprises a compression assembly with a closed system air bag having a fixed air volume fastened on the human body measuring site; a sensor coupled to the air bag for sensing pressure change inside the air bag; a processor for processing the pressure change; and a display. Through the use of the mechanical compression assembly, the pressure inside the air bag can be increased and steadily released to achieve the same measuring effects as traditional sphygmomanometer/sphygmometer. The apparatus invention also comprises a deactivation assembly and an alarm for safety purpose.

Description:
FILED OF THE INVENTION 
   The present invention relates to sphygmomanometers and sphygmometers and more particularly to a method for measuring blood pressure and pulse rate with a pump-less mechanical compression apparatus. 
   BACKGROUND OF THE INVENTION 
   As defined, blood pressure is the pressure exerted by the blood against the inner walls of the blood vessel, especially the arteries. Also, heart can receive blood from the veins and pump it through the arteries by alternate dilation and contraction. As such, pressure can be expressed as either contraction pressure (i.e., pressure exerted by the blood pumped from the heart against the inner walls of the arteries) or dilation pressure (i.e., exerted by the blood against the inner walls of the arteries when the heart stops contracting in a predetermined short period of time). Pulse rate can also be measured by a typical electronic sphygmometer. As defined, pulse is the regular beating in the arteries caused by the contraction and the dilation of the heart. 
   A typical electronic sphygmomanometer is advantageous for being compact, having a digital display, and without the cooperation of a stethoscope. Thus, the typical electronic sphygmomanometers are gaining popularity among consumers. The typical electronic sphygmomanometer is characterized in that an air bag is inflated by a pump, then pressure of the air bag is slowly released by a pressure release device, a sensor is deformed due to the pressure change inside the air bag, the differential electrical resistance of the sensor is then measured by the Wheatstone bridge, and finally a blood pressure is displayed. 
   Referring to  FIG. 1 , there is shown a block diagram of the typical electronic sphygmomanometer. The sphygmomanometer comprises a processor, an air pump controlled by the processor for pumping air into an air bag until a predetermined pressure is reached, a slow pressure release device is adapted to release pressure of the air bag, and other associated devices (e.g., power, alarm, display, sensor, trigger, fastening device, and quick pressure release device). However, the prior art suffers from several disadvantages. For example, for the sake of portability and the trend of compactness, the bulky pump and pressure release devices are not desirable. Further, strong noise is generated by the pump and the pressure release devices in operation. Hence, a need for improvement exists. 
   SUMMARY OF THE INVENTION 
   It is an object of the present invention to provide a method for measuring blood pressure and pulse rate by activating a pump-less mechanical compression apparatus, comprising the steps of fastening the unit with an air bag, which is a closed system containing fixed air volume, on the human body measuring site; activating the mechanical compression assembly to exert pressure on the air bag towards the human body and thus increase the pressure inside the air bag; release the mechanical compression on the air bag for the air bag pressure to steadily return to its original state and allow the sensor to measure the pressure change for calculating values; sending the values to the processor; processing the values by the processor to obtain a blood pressure including a contraction pressure and a dilation pressure, and a pulse rate; and showing the contraction pressure, the dilation pressure, and the pulse rate on a display. 
   It is another object of the present invention to provide a pump-less mechanical compression apparatus applied on a sphygmomanometer/sphygmometer, comprising a closed system air bag containing fixed air volume fastened on the human body; a sensor coupled to the air bag for sensing pressure change inside the air bag; a processor for processing the pressure change; a display for showing the measured contraction pressure, dilation pressure, and pulse rate; and a compression assembly, whereby activating the mechanical compression assembly to exert pressure on the air bag towards the human body measuring site will cause the pressure inside the air bag to increase and when the compression assembly is deactivated, the pressure will decrease and the change will be transmitted to the sensor and the processor for processing sequentially in order to calculate a contraction pressure, a dilation pressure, and a pulse rate, and show the contraction pressure, the dilation pressure, and the pulse rate on the display. 
   The above and other objects, features and advantages of the present invention will become apparent from the following detailed description taken with the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a block diagram of a conventional electronic sphygmomanometer; 
       FIGS. 2A and 2B  are exploded views of a pump-less mechanical compression sphygmomanometer/sphygmometer according to the invention; 
       FIGS. 3A and 3B  are cross-sectional views of the pump-less mechanical compression sphygmomanometer/sphygmometer of the invention for illustrating the expanded and the contracted states of the closed system air bag respectively; 
       FIGS. 4A and 4B  are side elevational views for illustrating the process of changing from the operating state to the disabled state of the deactivation assembly; 
       FIG. 5  is a block diagram of the pump-less mechanical compression sphygmomanometer/sphygmometer of the invention; and 
       FIG. 6  is a flow chart illustrating a process according to the invention. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Referring to  FIG. 5 , the pump-less mechanical compression apparatus applied on a sphygmomanometer/sphygmometer comprises a fastening device  30  having an air bag  20 , which is a closed system with fixed air volume, fastened at the measuring site (e.g., the wrist) of the body, a sensor  40  coupled to the air bag  20  for sensing pressure change inside the air bag  20 , a processor  50  for processing the pressure change, a display  60  for showing the measured results of contraction pressure, dilation pressure, and pulses in a digital form, and a compression assembly  10 . During compression, the compression assembly  10  is adapted to gradually exert pressure on the air bag  20  towards the measuring site such as the wrist. The pressure is increased inside the air bag and the pressure change is detected by the sensor  40 . During decompression, the compression assembly  10  is adapted to gradually return to its original state and thus the pressure on the air bag  20  is decreased. The pressure change inside the air bag  20  is detected by the sensor  40 . This forms a small, pump-less, mechanical compression sphygmomanometer/sphygmometer of the invention. 
   Referring to  FIGS. 2A and 2B , components of the inventions will be described in detail below. The compression assembly  10  comprises a holed, annular seat  11  including a lower, central cavity for receiving the air bag  20 , two opposite, upper arc walls  111  around a hole thereof, and two opposite slots  112 , an abutment disk  12  on top of the air bag  20 , a sleeve-like moveable member  13  on the abutment disk  12 , the moveable member  13  being moveable within a predetermined distance to and fro in the hole of the seat  11 , the moveable member  13  having internal threads  131  and two opposite projections  132  on its outer surface, the projections  132  being slidably fitted in the slots  112 , a force exertion assembly  14  for exerting a turning force on the moveable member  13  or stopping exerting force thereon, the force exertion assembly  14  including an annular, holed turning member  16  including a central, externally threaded extension  161  on the underside, the externally threaded extension  161  being coupled to the internal threads  131 , an annular flange  162  around a hole of the turning member  16 , and a ring  163  put on the flange  162 , the ring  163  having three spaced external hooks  164 , a gear  15  including a ratchet section  151  on its underside for catching and holding the hooks  164 , and an annular, toothed section  152  on its top, a speed regulator  18  including a shaft  181  having threads coupled to the toothed section  152 , a cylinder  182  having external threads coupled to the shaft  181 , and a weight  183  provided on the cylinder  182 , and a mainspring  17  anchored around the arc walls  111 , and a deactivation assembly  19  including a lever element  191  having a pivot  194 , a connecting element  193  at one end coupled to the cylinder  182 , a trigger element  192  at the other end, and a spring  195 . 
   Referring to  FIG. 6  in conjunction with  FIGS. 3A ,  3 B, and  5 , a process of the invention comprises the following steps: 
   Step a: Fasten the air bag  20  at the measuring site (e.g., the wrist) of the body by wrapping the fastening device therearound. 
   Step b: Activate the compression assembly  10  to gradually exert pressure on the air bag  20  and onto the wrist. At the same time, the sensor  40  senses the pressure change inside the air bag  20 . In the pressure exertion process, the turning member  16  rotates a number of times. Further, the internal threads  131  move downward due to threaded connection to the externally threaded extension  161 . The abutment disk  12  then moves downward in response to the downward movement of the moveable member  13 . Next, the air bag  20  contracts to press on the wrist in response to the downward movement of the abutment disk  12 . The pressure change inside the air bag  20  is transmitted to the sensor  40  through the duct  80  which is coupled to and connected between the air bag  20  and the sensor  40 . Also, the mainspring  17 , being connected to the arc walls  111  and annular seat  11 , is coiled during the pressure exertion process for storing elastic energy. Further, the gear  15  is motionless in the pressure exertion process because the rotating direction of hooks  164  does not positively engage the ratchet section  151 . 
   Step c: Release pressure of the compression assembly  10  for returning the air bag  20  to its original state in which the pressure change inside the air bag  20  is transmitted to the sensor  40  for calculating a value. 
   Step d: The value is sent from the sensor  40  to the processor  50  for processing in order to obtain a corresponding blood pressure including a contraction pressure and a dilation pressure, and a pulse rate. Note that all of the contraction pressure and dilation pressure, and the pulse rate are measured during the decompression (deflating) process of the air bag  20 . In detail, the stored elastic force of the mainspring  17  is released gradually by uncoiling for facilitating the upward movement of the moveable member  13 . Moveable member  13  moves upward while the expanding air bag  20  urges against the abutment disk  12 . Further, the turning member  16  rotates in a direction opposite to that in pressure exertion process due to the upward movement of the moveable member  13 . The ring  163  and ratchet section  151  are positively engaged and thus the gear  15  is free to rotate. The speed regulator  18  aims at providing a constant rotation mode in which the cylinder  182  is adapted to provide a constant rotating speed, the relative rotating speed of the shaft  181  about the gear  15  is determined by the cylinder  182  with the gear  15 , the turning member  16 , the moveable member  13 , and the abutment disk  12  being moved upward, and the weight  183  is adapted to provide a steady upward movement of the same. This facilitates the obtaining of a more precise blood pressure and the pulse rate. 
   Step e: Contraction pressure, dilation pressure, and pulse rate are transmitted from the processor  50  to the display  60  for showing in a digital form. The invention further comprises an alarm  70  coupled to the processor  50 . The alarm  70  will issue a warning when output pressure of the compression assembly  10 , as sensed by the sensor  40 , reaches a limit value. 
   It is possible that a person may feel uncomfortable during the blood pressure measuring process while pressure exerted on his/her wrist by the air bag  20  is increasing. In this case the person or the medical worker has to activate the deactivation assembly  19  to disable the pump-less mechanical compression apparatus applied in sphygmomanometer/sphygmometer via the speed regulator  18 . Referring to  FIGS. 4A and 4B , the operation of the deactivation assembly  19  is described below. In response to exerting force on the trigger element  192  of the lever element  191 , the lever element  191  moves downward for compressing the spring  195  for storing elastic force therein. Next, the lever element  191  pivots about the pivot  194  for causing the connecting element  193  to lift and the cylinder  182  is thus slanted by the connecting element  193 . Next, the slanted cylinder  182  disengages from the shaft  181 . As such, rotation of the toothed section  152  of the gear  15  is not stopped by the shaft  181 . As a result, the compressed states of the air bag  20  and thus the wrist of the person are changed to the uncompressed states by the release of the stored elastic force of the mainspring  17  if a person feels uncomfortable during the blood pressure measuring process. Once being uncompressed, the stored elastic force of the spring  195  below the trigger element  192  is released immediately to cause all components of the deactivation assembly  19  to return to their original states. 
   It will be evident from the foregoing that the invention has the following advantages: No provision of the bulky pump and pressure release device, resulting in compactness. Also, minimal noise is generated while measuring blood pressure and pulse rate. Moreover, the speed regulator  18  can provide a stable and steady decompression rate for pressure release and thus help facilitate the obtaining of a more precise blood pressure and the pulse rate. 
   While the invention herein disclosed has been described by means of specific embodiments, numerous modifications and variations could be made thereto by those skilled in the art without departing from the scope and spirit of the invention set forth in the claims.