Parameter variation for proportional assist ventilation or proportional positive airway pressure support devices

• US 6,532,956 B2
• Filed: 03/20/2001
• Issued: 03/18/2003
• Est. Priority Date: 03/30/2000
• Status: Expired due to Term

• Current Assignee: RIC INVESTMENTS LLC (Koninklijke Philips N.V.)
• Original Assignee: Respironics Incorporated (Koninklijke Philips N.V.)
• Inventors: Hill, Peter D.
• Primary Examiner(s): Lewis, Aaron J.
• Assistant Examiner(s): MITCHELL, TEENA KAY
• Application Number:
  US09/813,189
• Publication Number:
  US 20010035186A1
• Time in Patent Office: 728 Days
• Field of Search: 128/204.18, 128/204.21, 128/204.23, 128/204.26, 600/529, 600/533, 600/538
• US Class Current: 128/204.18
• CPC Class Codes: A61M 16/00 Devices for influencing the respiratory system of patients by gas treatment, e.g. mouth-to-mouth respiration; Tracheal tubes stimulating the respiratory movement by mechanical, pneumatic or electrical means, iron lungs combined with gas breathing means A61H31/00
• CPC Class Codes: A61M 16/0069 the speed thereof being controlled by respiratory parameters, e.g. by inhalation
• CPC Class Codes: A61M 16/024 including calculation means, e.g. using a processor
• CPC Class Codes: A61M 16/06 Respiratory or anaesthetic masks
• CPC Class Codes: A61M 16/101 using an oxygen concentrator
• CPC Class Codes: A61M 16/161 with means for measuring the humidity
• CPC Class Codes: A61M 2016/0021 with a proportional output signal, e.g. from a thermistor
• CPC Class Codes: A61M 2016/0027 pressure meter
• CPC Class Codes: A61M 2016/0039 in the inspiratory circuit
• CPC Class Codes: A61M 2016/103 the CO2 concentration
• CPC Class Codes: A61M 2205/15 Detection of leaks
• CPC Class Codes: A61M 2205/502 User interfaces, e.g. screens or keyboards
• CPC Class Codes: A61M 2205/505 Touch-screens; Virtual keyboard or keypads; Virtual buttons; Soft keys; Mouse touches
• CPC Class Codes: A61M 2230/432 partial CO2 pressure (P-CO2)

Abstract

A system and method for providing a pressure support therapy administered to a patient, where at least one parameter associated with the pressure support therapy is varied according to a time-base parameter variation function. More specifically, at least one parameter or at least one group of parameters associated with a pressure control relation for providing a proportional assist ventilation (PAV) or a proportional positive airway pressure (PPAP) mode of ventilation is varied according to a time-based parameter variation function to control the PAV or PPAP ventilation with a maximum degree of flexibility.

Claims

1. A patient treatment system comprising:

gas flow generating means for providing a flow of breathing gas to an airway of a patient;

pressure controlling means, associated with the gas flow generating means, for controlling a pressure of breathing gas provided to an airway of such a patient;

sensing means for detecting an instantaneous flow rate V and an instantaneous volume V of the flow of breathing gas provided to such a patient; and

processing means, associated with the sensing means and the pressure controlling means, for controlling the pressure controlling means such that the flow of breathing gas is provided to such a patient at a pressure in accordance with the following relation;

2. A system according to claim 1, wherein parameter variation functions R₁(t), R₂(t), R₃(t), R₄(t), and R₅(t) are independent of one another.

3. A system according to claim 1, wherein the gas flow generating means comprises:

a blower that receives a supply of breathing gas an elevates a pressure of such gas and output a flow of breathing gas;

a patient circuit having a first end coupled to the blower and a second end, wherein the patient circuit carries the flow of breathing gas; and

a patient interface coupled to the second end of the patient circuit to communicate the flow of breathing gas from the patient circuit to an airway of a patient, and wherein the pressure controlling means comprises at least one of;

(a) a control valve coupled to the patient circuit that controls a pressure of flow of breathing gas delivered to a patient by at least one of exhausting gas from the patient circuit and restricting the flow of breathing gas in the patient circuit; and

(b) a variable speed motor coupled to the blower that controls a pressure of the flow of breathing gas delivered to a patient by controlling a rotational velocity of the blower, and, hence, a pressure of the flow of breathing gas output by the blower.

4. A system according to claim 1, further comprising an input/output means for setting at least one of the % Set, FA, VA, EPAP, R₁(t), R₂(t), R₃(t), R₄(t), and R₅(t).

5. A system according to claim 1, further comprising a memory for storing information regarding at least one of the % Set, FA, VA, EPAP, R₁(t), R₂(t), R₃(t), R₄(t), and R₅(t).

6. A method of treating a patient comprising:

providing a flow of breathing gas to an airway of a patient;

detecting an instantaneous flow rate {dot over (V)} and an instantaneous volume V of the flow of breathing gas provided to such a patient; and

controlling a pressure of breathing gas provided to an airway of such a patient in accordance with the following relation;

7. A method according to claim 6, further comprising setting parameter variation functions R₁(t), R₂(t), R₃(t), R₄(t), and R₅(t) independent of one another.

8. A method according to claim 6, wherein providing a flow of breathing gas to an airway of a patient includes:

generating the flow of breathing gas via a blower;

carrying the flow of breathing gas to a patient via a patient circuit having a first end coupled to the blower and a second end; and

communicating the flow of breathing gas to an airway of such a patient via a patient interface coupled to the second end of the patient circuit, and

wherein controlling the pressure of the breathing gas provided to the patient includes least one of;

(a) exhausting gas from the patient circuit,

(b) restricting the flow of breathing gas in the patient circuit, and

(c) controlling a rotational velocity of the blower, and, hence, a pressure of the flow of breathing gas output by the blower.

9. A method according to claim 6, further comprising setting at least one of the % Set, FA, VA, EPAP, R₁(t), R₂(t), R₃(t), R₄(t), and R₅(t) using an input/out device.

10. A method according to claim 6, further comprising storing in a memory information regarding at least one of the % Set, FA, VA, EPAP, R₁(t), R₂(t), R₃(t), R₄(t), and R₅(t).