Device for measuring inspiratory strength

Abstract

A device having variable inspiratory resistance suitable for measuring the inspiratory strength of a patient which comprises a chamber in communication with a mouthpiece, said chamber (a) being provided with a calibration system for measuring the inhalation flow rate during inhalation through the mouthpiece and (b) being provided with a variable resistance feature by which the resistance to airflow through the device may be altered.

1 - 22 . (canceled)  
   
   
       23 . A device having variable inspiratory resistance suitable for measuring the inspiratory strength of a patient comprising: 
 an elongate chamber having first and second ends and defining a pathway and adapted for air to enter the second end;    a calibration system adapted to measure an inhalation flow rate; and    a variable inspiratory resistance system adapted to include at least one specified setting that provides the device with a resistance matching that of an inhalation device.    
   
   
       24 . The device of  claim 23 , wherein the chamber has a circular cross sectional area.  
   
   
       25 . The device of  claim 23 , wherein the calibration system includes calibrations along the length of the chamber.  
   
   
       26 . The device of  claim 23 , wherein the calibration system includes a sliding member located within the chamber, wherein the sliding member is adapted to slide and be retained within the chamber and has calibrations along its length, and wherein a distance of travel by the sliding member from a rest position indicates a patient's maximum inspiratory flow rate.  
   
   
       27 . The device of  claim 26 , wherein the sliding member includes a rod located along the chamber axis and adapted to guide movement of the sliding member.  
   
   
       28 . The device of  claim 26 , further comprising a means for restoring the sliding member to rest position.  
   
   
       29 . The device of  claim 23 , wherein the variable resistance system includes an iris.  
   
   
       30 . The device of  claim 23 , wherein the variable resistance system includes first and second co-operating aperture-bearing plates adapted to vary the area through which air leaves the chamber by orienting the plates.  
   
   
       31 . The device of  claim 30 , wherein the first and second plates include at least two apertures.  
   
   
       32 . The device of  claim 31 , including two or more orientations each defining a specific area.  
   
   
       33 . The device of  claim 23 , wherein the variable inspiratory resistance system is adapted to vary the area through which air leaves the chamber at the first end or enters the chamber at the second end.  
   
   
       34 . The device of  claim 23 , wherein the first end of the elongate chamber is in communication with a mouthpiece.  
   
   
       35 . A device having variable inspiratory resistance suitable for measuring the inspiratory strength of a patient comprising: 
 an elongate chamber having first and second ends and defining a pathway and adapted for air to enter the second end;    a calibration system adapted to measure an inhalation flow rate; and    a variable resistance system adapted to vary the area through which air leaves the chamber at the first end, wherein the variable resistance system includes a co-operating section, with at least one aperture, the outer surface of which section in conjunction with a portion of the inner surface of the chamber defines a ring, the area of which may be altered by rotational movement of the chamber along its longitudinal axis relative to the co-operating section, and wherein at least part of the chamber or co-operating section is tapered.    
   
   
       36 . The device of  claim 35 , wherein the outer surface of the co-operating section is tapered.  
   
   
       37 . The device of  claim 35 , wherein the inner surface of the chamber and the outer surface of the co-operating section are tapered.  
   
   
       38 . The device of  claim 35 , adapted to provide two or more specific positions along the axis which each correspond to a ring of a defined area.  
   
   
       39 . The device of  claim 38 , wherein at least one position on the axis and the associated ring area provide a resistance which corresponds to the resistance of an inhalation device.  
   
   
       40 . The device of  claim 35 , wherein the rotational motion is by means of a screw and thread system.  
   
   
       41 . The device of  claim 35 , wherein the calibration system includes a sliding member located within the chamber, and wherein the sliding member is adapted to slide and be retained within the chamber.  
   
   
       42 . A device having variable inspiratory resistance suitable for measuring the inspiratory strength of a patient comprising: 
 an elongate chamber having first and second ends and defining a pathway and adapted for air to enter the second end wherein the first end of the chamber is in communication with a mouthpiece;    a calibration system adapted to measure an inhalation flow rate; and    a variable inspiratory resistance system adapted to vary the area through which air leaves the chamber at the first end or enters the chamber at the second end, and further adapted to include at least one specified setting that provides the device with a resistance matching that of an inhalation device.