Ambulatory ECG triggered blood pressure monitoring system and method therefor

• US 5,322,069 A
• Filed: 05/24/1993
• Issued: 06/21/1994
• Est. Priority Date: 11/12/1991
• Status: Expired due to Fees

• Current Assignee: Protocol Systems Inc
• Original Assignee: Stuart Medical, Inc.
• Inventors: Gallant, Stuart L., Caron, Paul R., Palmer, Walter E.
• Primary Examiner(s): Kamm, William E.
• Application Number:
  US08/064,928
• Time in Patent Office: 393 Days
• Field of Search: 128/670, 128/672, 128/680-683, 128/708, 128/900, 128/908
• US Class Current: 600/513
• CPC Class Codes: A61B 5/0205 Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition
• CPC Class Codes: A61B 5/02208 using the Korotkoff method
• CPC Class Codes: A61B 5/02225 using the oscillometric method
• CPC Class Codes: A61B 5/0225 the pressure being controlled by electric signals, e.g. derived from Korotkoff sounds
• CPC Class Codes: A61B 5/335 using integrated circuit memory devices
• CPC Class Codes: A61B 5/7232 involving compression of the physiological signal, e.g. to extend the signal recording period
• CPC Class Codes: A61B 5/7285 for synchronising or triggering a physiological measurement or image acquisition with a physiological event or waveform, e.g. an ECG signal A61B6/5205, A61B6/541, A61B8/5207, A61B8/543 take precedence
• CPC Class Codes: A61B 7/045 Detection of Korotkoff sounds A61B5/0225 takes precedence; measuring blood pressure A61B5/021
• CPC Class Codes: Y10S 128/90 Blood pressure recorder
• CPC Class Codes: Y10S 128/908 Patient protection from electric shock

Abstract

An ambulatory patient monitoring system (100) is provided for measuring and storing predetermined diagnostic parameters of a patient. The monitoring system includes a personal type computer (120) which may be selectively coupled to the portable portion (102) of system (100). Portable portion (102) may include one or more monitoring modules, such as ECG monitoring unit (110) and blood pressure monitoring unit (210). When ECG monitoring unit (110) and blood pressure monitoring unit (210) are disposed in side-by-side relationship and with respective optical interfaces (50, 254) in optical alignment, the two units operate in concert. ECG monitoring unit (110) supplies an R-wave gating signal to blood pressure monitoring unit (210) for establishing a window in which the receipt of a Korotkoff sound is expected. Additionally, the ECG unit (110) may trigger the blood pressure unit (210) to take a reading responsive to unit (110) identifying a predetermined abnormality in the ECG signal. Alternately, ECG monitoring unit (110) and blood pressure monitoring unit (210) may be used independently of one another as separate monitoring devices.

Claims

1. An ambulatory patient monitoring system for measuring and storing a plurality of blood pressure values powered by a portable power source, comprising:

a portable housing coupled to a patient, said portable power source being disposed within said portable housing;

microprocessor means disposed within said portable housing and coupled to said portable power source for (1) generating an inflate command control signal, (2) generating a deflate command control signal, and (3) determining said blood pressure values;

memory means disposed within said portable housing and coupled to said microprocessor means for storing said plurality of blood pressure values;

optical interface means disposed within said portable housing and coupled to said microprocessor means for receiving at least one control signal from an external monitoring unit, said microprocessor means generating said inflate command signal to initiate a blood pressure measurement responsive to receipt of said control signal from said external monitoring unit;

transducer means coupled to said microprocessor means for providing measurement data thereto, said microprocessor means calculating said blood pressure values from said measurement data, said transducer means including an inflatable cuff for occluding an artery of a patient;

inflation means coupled in fluid communication with said inflatable cuff and coupled to said microprocessor means for inflation of said inflatable cuff responsive to said inflate command control signal from said microprocessor means; and

,

deflation means coupled in fluid communication with said inflatable cuff and coupled to said microprocessor means for deflation of said inflatable cuff responsive to said deflate command control signal from said microprocessor means.

2. An ambulatory patient monitoring system for measuring and storing a plurality of blood pressure values powered by a portable power source, comprising:

a portable housing coupled to a patient, said portable power source being disposed within said portable housing;

transducer means coupled to a patient for providing measurement data, said transducer means including (1) an audio transducer for detecting K sounds, (2) an inflatable cuff for occluding an artery of a patient, and (3) a pressure transducer fluidly coupled to said inflatable cuff for measuring a plurality of cuff pressure values;

microprocessor means disposed within said portable housing and coupled to said portable power source for (1) generating an inflate command control signal, (2) generating a deflate command signal, and (3) determining said blood pressure values from said K sounds and said cuff pressure values;

memory means disposed within said portable housing and coupled to said microprocessor means for storing said plurality of blood pressure values, said K sounds, and said plurality of cuff pressure values;

means for supplying fluid to said inflatable cuff, said fluid supply means being coupled to said microprocessor means for actuation thereof responsive to said inflate command control signal from said microprocessor means; and

,

means for deflating said inflatable cuff coupled to said microprocessor means for deflating said inflatable cuff responsive to said deflate command signal from said microprocessor means.

3. A method of rapidly determining a systolic blood pressure measurement of a patient substantially concurrently with an arrhythmia, comprising the steps of:

a. providing an ECG monitoring unit having a plurality of electrodes and coupling said plurality of electrodes to a patient for conducting ECG signals therefrom, said ECG monitoring means including means for detecting arrhythmias from said ECG signals;

b. detecting an arrhythmia and generating an optical signal responsive thereto;

c. providing a blood pressure measurement controller for receiving said optical signal from an ECG monitoring unit;

d. providing an inflatable cuff and coupling said inflatable cuff to the patient;

e. inflating said inflatable cuff to a predetermined pressure responsive to said receipt of said optical signal;

f. deflating said cuff by a predetermined incremental pressure step;

g. checking for detection of K sounds;

h. repeating said steps f. through g. until said K sounds are detected; and

,

i. storing a cuff pressure value as a systolic pressure value responsive to said detection of said K sounds.

4. The method as recited in claim 3 where the step of deflating includes the step of reducing said cuff pressure by an incremental step in pressure within a range of 5.0-10.0 millimeters of Hg.

5. A method of rapidly determining a systolic blood pressure measurement substantially concurrently with a heart rate abnormality, comprising the steps of:

a. providing an ECG monitoring unit having a plurality of electrodes and coupling said plurality of electrodes to a patient for conduction of ECG signals therefrom, said ECG monitoring unit including means for detecting occurrences of heart abnormalities from said ECG signals;

b. detecting an occurrence of a heart abnormality and generating an optical signal responsive thereto;

c. providing a blood pressure measurement controller for (1) receiving said optical signal from said ECG monitoring unit, and (2) generating a first control signal responsive to receipt of said optical signal, said blood pressure measurement controller including timing means for generating a second control signal at predetermined time increments;

d. providing an inflatable cuff and coupling said cuff to the patient;

e. inflating said cuff to a predetermined pressure responsive to a respective one of said first or second control signals;

f. deflating said cuff, said cuff deflation being at a respective one of (1) a first incremental pressure value responsive to said first control signal, or (2) a second incremental pressure value responsive to said second control signal, said first incremental pressure value being greater than said second incremental pressure value;

g. checking for detection of K sounds;

h. repeating said steps f. through g. until said K sounds are detected; and

,

i. storing a cuff pressure value as a systolic pressure value responsive to said detection of said K sounds.

6. A method of ambulatory blood pressure measurement, comprising the steps of:

a. providing a pressure cuff and coupling said cuff to a patient;

b. providing a pressure transducer coupled in fluid communication with said cuff for measuring pressure values thereof;

c. inflating said cuff to a predetermined first pressure value;

d. deflating said cuff to a plurality of second pressure values in a succession of predetermined increments;

e. providing an audio transducer for detecting K sounds from said patient and converting said K sounds to electrical signals;

f. providing means for filtering said electrical signals and establishing an envelope signal representing an absolute value representation of said filtered electrical signals;

g. providing means for detecting a peak value of said envelope signal;

h. identifying a first of said second pressure values as a systolic pressure value responsive to a detection of said peak value of said envelope signal;

i. providing a non-volatile memory and storing in said non-volatile memory (1) said systolic pressure value, (2) subsequent second pressure values, (3) said filtered electrical signals, and (4) said envelope signal;

j. identifying one of said plurality of second pressure values as a diastolic pressure value responsive to termination of said detection of K sounds; and

,

k. storing said diastolic pressure value in said non-volatile memory.