Inspiratory airway pressure system controlled by the detection and analysis of patient airway sounds

• US 5,259,373 A
• Filed: 04/09/1992
• Issued: 11/09/1993
• Est. Priority Date: 05/19/1989
• Status: Expired due to Term

• Current Assignee: Nellcor Puritan Bennett LLC (Medtronic Plc)
• Original Assignee: Puritan Bennett Corp. (Medtronic Plc)
• Inventors: Snook, James A., Wyble, Marilyn S., Loethen, Steven W., Lasnier, Christopher D., Orlt, Jiri G., Gruenke, Roger A., Trimble, Russell L.
• Primary Examiner(s): Burr, Edgar S.
• Assistant Examiner(s): Asher, Kimberly L.
• Application Number:
  US07/846,133
• Time in Patent Office: 579 Days
• Field of Search: 128/204.18, 128/204.21, 128/204.23, 128/, 128/207.18, 128/207.14, 128/719, 128/724, 128/670, 128/205.25, 128/207.13
• US Class Current: 128/204.23
• CPC Class Codes: A61B 5/4818 Sleep apnoea
• CPC Class Codes: A61F 5/56 Devices for preventing snoring by influencing the respiratory system by gas treatment A61M16/00
• CPC Class Codes: A61M 16/0069 the speed thereof being controlled by respiratory parameters, e.g. by inhalation
• CPC Class Codes: A61M 16/026 specially adapted for predicting, e.g. for determining an information representative of a flow limitation during a ventilation cycle by using a root square technique or a regression analysis
• CPC Class Codes: A61M 16/06 Respiratory or anaesthetic masks
• CPC Class Codes: A61M 16/0633 with forehead support
• CPC Class Codes: A61M 16/0683 Holding devices therefor
• CPC Class Codes: A61M 16/1055 bacterial
• CPC Class Codes: A61M 16/107 in the inspiratory path
• CPC Class Codes: A61M 16/204 used for inhalation control
• CPC Class Codes: A61M 16/205 used for exhalation control
• CPC Class Codes: A61M 2016/0021 with a proportional output signal, e.g. from a thermistor
• CPC Class Codes: A61M 2016/0039 in the inspiratory circuit
• CPC Class Codes: A61M 2205/054 with electrotherapy
• CPC Class Codes: A61M 2205/3561 local, e.g. within room or hospital
• CPC Class Codes: A61M 2210/0618 Nose

Abstract

An apparatus and method for facilitating the respiration of a patient detects patient airway sounds and resolves these sounds into audio component bands whereupon an analysis is performed to produce a trend value. In response, a pressure action is determined using the trend value for controlling the pressure delivered to a patient for preventing the onset of obstructive apnea.

Claims

1. An apparatus for facilitating respiration of a patient, the patient exhibiting detectable sounds associated with respiration and exhibiting a breath cycle having inhalation and exhalation phases, the respiration-associated sounds including a spectrum of frequencies, said apparatus comprising:

means for detecting a patient'"'"'s respiration-associated sounds; and

control means, including means for operably coupling with a gas delivery device having means for controllably pressurizing at least a portion of a patient'"'"'s respiration passages with a breathable gas from a source thereof, and coupled with and responsive to said detecting means, for controlling the gas pressure delivered to at least a portion of a patient'"'"'s respiratory passages in accordance with said detected sounds, said control means including means for

resolving said airway sounds into a plurality of spectral bands of audio components making up said sounds;

producing an analysis of said spectral bands;

producing in response to said analysis a trend value representative of the breath sounds of at least two breaths;

storing in memory predetermined matter correlated with pressure actions for presenting the minimum pressure necessary to a patient for preventing the onset of obstructive apnea;

determining one of said pressure actions from said predetermined matter using said trend value; and

controlling said gas pressure in accordance with said one of said pressure actions thereby presenting the minimum pressure necessary to a patient for preventing the onset of obstructive apnea.

2. The apparatus as set forth in claim 1, said detecting means including a pressure transducer.

3. The apparatus as set forth in claim 1, said detecting means including a microphone.

4. The apparatus as set forth in claim 1, said detecting means being operable for producing detection signals in response to said sounds and representative thereof.

5. The apparatus as set forth in claim 1, said control means including a microprocessor.

6. The apparatus as set forth in claim 1, a patient sounds including snoring sounds.

7. The apparatus as set forth in claim 6, said control means being operable for repetitively increasing gas pressure until the snoring sounds are no longer detected.

8. The apparatus as set forth in claim 6, said control means being operable for decreasing said gas pressure in the absence of snoring sounds.

9. The apparatus as set forth in claim 1, said sounds including audible sounds.

10. The apparatus as set forth in claim 1, said control means including means for resolving said sounds into low, medium and high bands.

11. The apparatus as set forth in claim 10, said low band being below about 200 Hz., said medium band being between about 200 and 800 Hz., and said high band being above about 800 Hz.

12. The apparatus as set forth in claim 1, said pressure actions including increased pressure, decreased pressure and maintained pressure.

13. The apparatus as set forth in claim 1 further including said gas delivery device coupled with said control means.

14. The apparatus as set forth in claim 13, said gas delivery device including means for coupling with a patient'"'"'s nasal passages for providing said pressure thereto.

15. A method of facilitating respiration of a patient, the patient exhibiting detectable sounds associated with respiration and exhibiting a breath cycle having inhalation and exhalation phases, the respiration-associated sounds including a spectrum of frequencies, said method comprising the steps of:

detecting a patient'"'"'s respiration-associated sounds;

coupling a gas delivery device with a patient, said device being operable for controllably pressurizing at least a portion of a patient'"'"'s respiration passages with a breathable gas from a source thereof, and operable for controlling the gas pressure delivered to at least a portion of a patient'"'"'s respiratory passages in accordance with said sounds;

resolving said airway sounds into a plurality of spectral bands of audio components making up said sounds;

producing an analysis of said spectral bands;

producing in response to said analysis a trend value representative of the breath sounds of at least two breaths of a patient;

storing in memory predetermined matter correlated with pressure actions for presenting the minimum pressure necessary to a patient for preventing the onset of obstructive apnea;

determining one of said pressure actions from said predetermined matter using said trend value; and

controlling said gas pressure in accordance with said one of said pressure actions thereby presenting the minimum pressure necessary to a patient for preventing the onset of obstructive apnea.