APPARATUS AND METHODS FOR CALIBRATING AND/OR VALIDATING PULMONARY FUNCTION TEST EQUIPMENT
The present invention relates to quality control of pulmonary function test (PFT) devices. In particular, but not by way of limitation, the present invention relates to systems and methods for characterizing or verifying the measurement accuracy of pulmonary function testing devices used for measuring dynamic lung volumes (tidal volume (TV), inspiratory reserve volume (IRV), expiratory reserve volume (ERV), divisions thereof, and any other suitable dynamic lung volume) using spirometry, static and/or absolute lung volumes (total lung capacity (TLC), residual volume (RV), divisions thereof, and any other suitable absolute lung volume) using washout, dilution, and/or plethysmographic methods, and/or gas exchange, such as single-breath determination of carbon monoxide uptake in the lung (D LCO ).
1 . A method, comprising:
drawing ambient atmospheric gas having a room temperature into a syringe having a housing defining a primary surface area of the syringe, a piston, and a heat transfer element coupled to the housing and having a surface area at least three times greater than the primary surface area of the syringe;
transferring gas from the syringe into a pulmonary function test device; and
validating the pulmonary function test device based at least in part on a measurement of a volume of the gas transferred between the pulmonary function test device and the syringe.
2 . The method of claim 1 , wherein:
the syringe is in thermal contact with a surface at least 10 .degree. C. above the room temperature for an elapsed time of at least 2 minutes between drawing ambient atmospheric gas and transferring gas from the syringe; and
the specific volume of gas within the syringe changes by less than 0.2% between drawing ambient atmospheric gas into the syringe and transferring gas from the syringe.
3 . The method of claim 1 , wherein:
the syringe is in direct sunlight for at least 2 minutes between drawing ambient atmospheric gas and transferring gas from the syringe; and
the specific volume of gas within the syringe changes by less than 0.2% between drawing ambient atmospheric gas into the syringe and transferring gas from the syringe.
4 . The method of claim 1 , wherein the pulmonary function test device is validated to perform a dynamic lung volume test.
5 . The method of claim 1 , wherein the pulmonary function test device is validated to perform an absolute lung volume test.
6 . A device comprising:
a processor; and
a memory coupled with and readable by the processor and storing therein a set of instructions which, when executed by the processor, causes the processor to:
draw ambient atmospheric gas having a room temperature into a syringe having a housing defining a primary surface area of the syringe, a piston, and a heat transfer element coupled to the housing and having a surface area at least three times greater than the primary surface area of the syringe;
transfer gas from the syringe into a pulmonary function test device; and
validate the pulmonary function test device based at least in part on a measurement of a volume of the gas transferred between the pulmonary function test device and the syringe.
7 . The device of claim 6 , wherein:
the syringe is in thermal contact with a surface at least 10 .degree. C. above the room temperature for an elapsed time of at least 2 minutes between drawing ambient atmospheric gas and transferring gas from the syringe; and
the specific volume of gas within the syringe changes by less than 0.2% between drawing ambient atmospheric gas into the syringe and transferring gas from the syringe.
8 . The device of claim 6 , wherein:
the syringe is in direct sunlight for at least 2 minutes between drawing ambient atmospheric gas and transferring gas from the syringe; and
the specific volume of gas within the syringe changes by less than 0.2% between drawing ambient atmospheric gas into the syringe and transferring gas from the syringe.
9 . The device of claim 6 , wherein the pulmonary function test device is validated to perform a dynamic lung volume test.
10 . The device of claim 6 , wherein the pulmonary function test device is validated to perform an absolute lung volume test.
11 . A non-transitory, computer-readable medium comprising a set of instructions stored therein which, when executed by a processor, causes the processor to:
draw ambient atmospheric gas having a room temperature into a syringe having a housing defining a primary surface area of the syringe, a piston, and a heat transfer element coupled to the housing and having a surface area at least three times greater than the primary surface area of the syringe;
transfer gas from the syringe into a pulmonary function test device; and
validate the pulmonary function test device based at least in part on a measurement of a volume of the gas transferred between the pulmonary function test device and the syringe.
12 . The non-transitory, computer-readable medium of claim 11 , wherein:
the syringe is in thermal contact with a surface at least 10 .degree. C. above the room temperature for an elapsed time of at least 2 minutes between drawing ambient atmospheric gas and transferring gas from the syringe; and
the specific volume of gas within the syringe changes by less than 0.2% between drawing ambient atmospheric gas into the syringe and transferring gas from the syringe.
13 . The non-transitory, computer-readable medium of claim 11 , wherein:
the syringe is in direct sunlight for at least 2 minutes between drawing ambient atmospheric gas and transferring gas from the syringe; and
the specific volume of gas within the syringe changes by less than 0.2% between drawing ambient atmospheric gas into the syringe and transferring gas from the syringe.
14 . The non-transitory, computer-readable medium of claim 11 , wherein the pulmonary function test device is validated to perform a dynamic lung volume test.
15 . The non-transitory, computer-readable medium of claim 11 , wherein the pulmonary function test device is validated to perform an absolute lung volume test.