Nasal pillows with high volume bypass flow and method of using same

A method of providing gases by a gases supply system having control circuitry, a variable speed fan unit controlled by said control circuitry, and a user interface having a known geometry and known dimensions, said gases supply system supplying gases for therapeutic purposes to a user via said user interface, said method comprising:

• receiving, by said control circuitry, an initial parameter value to control said fan unit, said fan unit causing a stream of gases to flow to said user via said user interface;
• measuring, with a pressure sensor in said user interface, a differential pressure value between atmospheric pressure and a pressure at said user interface and transmitting data representative of said measured differential pressure value to said control circuitry;
• measuring, with a flow sensor in fluid communication with said stream of gases, a flow rate value of said stream of gases and transmitting data reflective of said measured flow rate value to said control circuitry,
• calculating, by said control circuitry, an actual pressure value in an airway of said user based on said measured differential pressure data, said measured flow rate data, and said known geometry and known dimensions of said interface,
• causing said control circuitry to send a control signal to said fan unit to increase or decrease a speed of said fan unit so that said calculated difference between said calculated actual pressure value and said initial parameter value is decreased.

A system for providing gases to a patient having an airway and nares, said system comprising:

• a blower unit having control circuitry and a variable speed fan unit controlled by said control circuitry;
• a conduit having a first end and a second end, said conduit in fluid communication with said blower unit at said first end;
• a user interface in fluid communication with said second end of said conduit, said user interface comprising:
• a substantially hollow main body, adapted for attachment to said second end of said conduit so that in use said gases stream from said conduit and enter said main body;
• a pair of nasal pillows, in fluid connection with said main body, a portion of an outer surface of each one of said nasal pillows adapted so that in use each of said nasal pillows can substantially seal against the respective one of said nares of said patient;
• each one of said pair of nasal pillows divided into three separate passages, each of said passages sealed from the other passages at least within said pillows, the first one of said passages configured to act in use as a gases delivery passageway and connected to said main body so that in use gases from said conduit can pass along said first passage to said patient, the second one of said passages configured to act as a pressure measurement duct in use, and the third one of said passages open to atmosphere and adapted to act as a bypass passage, and further having known geometry and dimensions;
• said control circuitry configured to receive a parameter value that defines an initial rate at which said gases are to be provided to said airway of said patient, said blower providing said gases stream at said initial rate from said blower through said conduit to said user via said user interface;
• a pressure sensor, in said interface, configured to measure a differential pressure value between atmospheric pressure and a pressure at said user interface in use and to transmit data indicative of said measured differential pressure value to said control circuitry;
• a flow sensor, in said blower unit and in fluid communication with said gases stream, said flow sensor configured to measure a flow rate value of said gases stream provided by said blower and to transmit data indicative of said measured flow rate value to said control circuitry;
• said control circuitry configured to determine an actual pressure in said patient's airway by using said transmitted pressure data, said transmitted flow data, and said known geometry and dimensions of said user interface;
• said control circuitry configured to determine a difference between said determined actual pressure and said initial rate;
• and
• said control circuitry configured to send a control signal to said fan unit to increase or decrease a speed of said fan unit so that said determined difference between said calculated actual pressure and said initial rate is decreased.