Method and apparatus for long-term monitoring of physiological activity to provide a compact portable record

• US 4,519,398 A
• Filed: 01/21/1982
• Issued: 05/28/1985
• Est. Priority Date: 07/09/1979
• Status: Expired due to Term

• Current Assignee: Del Mar Avionics
• Original Assignee: Del Mar Avionics
• Inventors: Lisiecki, Andrew I., Wong, Alan S.
• Primary Examiner(s): Kamm, William E.
• Application Number:
  US06/341,309
• Time in Patent Office: 1,223 Days
• Field of Search: 346/33 ME, 128/690, 128/695, 128/696, 128/702, 128/703, 128/704, 128/706, 128/710, 128/711, 128/736
• US Class Current: 600/523
• CPC Class Codes: A61B 5/02 Detecting, measuring or recording pulse, heart rate, blood pressure or blood flow; Combined pulse/heart-rate/blood pressure determination; Evaluating a cardiovascular condition not otherwise provided for, e.g. using combinations of techniques provided for in this group with electrocardiography or electroauscultation; Heart catheters for measuring blood pressure
• CPC Class Codes: G11C 11/417 for memory cells of the field-effect type
• CPC Class Codes: G11C 17/18 Auxiliary circuits, e.g. for writing into memory

Abstract

The system enables ambulatory monitoring of a patient'"'"'s blood pressure and heart rate without the need for the patient to wear a portable magnetic tape recorder. The system takes the place of the tape recorder. ECG electrodes and a blood pressure cuff are affixed to the patient and are connected to a blood pressure measuring apparatus worn by the patient. The Data Acquisition and Storage System (DAS) is connected to the blood pressure measuring apparatus and includes a solid state storage device in which the successive measurements are stored. After the monitoring session, which may last 24 hours, the patient returns to the clinic, where the DAS is connected to a stationary charter that prints and plots the stored data in tabular and graphical form. The DAS includes a clock for determining the time of day at which the successive blood pressure readings are taken, and these times are stored along with the data. The clock is kept running even when the blood pressure measuring apparatus is disconnected from the DAS, so that when connection is reestablished the elapsed time can be determined. The clock also permits the heart rate to be determined and stored by the DAS. In the event the voltage of the source that powers the DAS should fall below a preset level, the DAS goes into a dormant mode to conserve power and prevent erroneous calculations. In the dormant mode the data stored in the solid state storage device is preserved.

Claims

1. A method for creating a long term chronology of a physiological parameter of a patient comprising the steps of:

coupling a portable, lightweight apparatus to said patient;

coupling transducers to said patient;

intermittently sensing said physiological parameter through transducers coupled to said patient and to said apparatus;

intermittently storing said physiological parameter sensed in a solid state memory included in said apparatus; and

intermittently storing a time-of-day signal in said memory corresponding to each one of said stored physiological parameters;

selectively ceasing said storing of said physiological parameter upon a power reduction; and

continuing said storing of said time-of-day signal during said power reduction,

whereby said chronology of patient'"'"'s physiological parameters is created.

2. A method of long-term monitoring physiological parameters and generating time dependent measures in a portable apparatus comprising the steps of:

intermittently measuring said physiological parameter;

intermittently storing said physiological parameter in a solid state memory included in said apparatus;

intermittently storing a corresponding time-of-day data signal in said memory in association with each said stored physiological parameter;

selectively ceasing said measuring of said physiological parameter upon a lower power condition;

continuing said storing of said time-of-day data signal during said low power condition;

retrieving said stored physiological parameters and said corresponding time-of-day signals,

whereby said stored physiological parameters, said stored time-of-day data signals and said measures comprise a compact chronological history of said measures and parameters in a portable memory having no moving parts.

3. A method for keeping a compact intermittent chronological long-term history of a physiological parameter in a portable apparatus worn by a patient comprising the steps of:

intermittently measuring said physiological parameter in a solid state memory;

generating a time-of-day signal in a clock included within said portable apparatus;

intermittently storing said time-of-day signal in said memory corresponding to measurement of said physiological parameter, said step of measuring performed at the chronological time and date indicated by said time-of-day signal;

detecting a low power condition in said portable apparatus;

reducing power consumption in said apparatus without stopping the steps of generating said time-of-day signal and storing said time-of-day signal in memory,

whereby said compact chronological history, at least with respect to time-of-day data, is kept accurate for when full power and operation is restored in said portable apparatus.

4. An improvement in a method for creating a compact chronological long-term record in a portable apparatus having a solid state memory and circuit for intermittently measuring and storing a physiological parameter in association with a time-of-day signal also stored in said memory, comprising the steps of:

detecting a lower power condition in said portable apparatus;

reducing power consumption in said apparatus;

maintaining adequate power to said memory to fully retain the contents thereof;

maintaining adequate power to a clock to continue to generate said time-of-day signa; and

continuing to store said time-of-day signal in said memory to maintain the time-of-day portion of said chronological record during said lower power condition.

5. The improvement of claim 4 wherein the step of reducing power consumption includes ceasing said measurement of said physiological parameter by said circuit.

6. The improvement of claim 4 or 5 further comprising the steps of:

restoring full power to said portable apparatus; and

restricting the storing of said physiological parameter corresponding to said time-of-day signal in said memory beginning with the then current state of said time-of-day signal, all prior time-of-day signals previously stored in said memory remaining in said memory.

7. An apparatus for generating a compact chronological long-term record of a physiological parameter comprising:

a main battery power supply;

an auxiliary battery power supply;

a circuit for intermittently measuring said physiological parameter;

a solid state memory for storing said physiological parameter normally coupled to said main battery power supply;

a clock means for generating a time-of-day signal and for storing said time-of-day signal in said memory, said clock means normally coupled to said main battery power supply; and

circuit means for reducing power consumption in said apparatus to maintain information in said memory and to generate said time-of-day signals in said clock means, said circuit means for coupling said auxiliary battery power supply to said memory and time-of-day clock when said main battery power supply fails, said circuit means for ceasing recordation of said physiological parameter and cessation of the storing of new measurements of said physiological parameter in said memory but still maintaining power to said clock means so that time-of-day signal continues to be stored in said memory when said circuit means detects power failure,

whereby said chronological record is maintained in said memory even during power failure so that when main power is restored to said apparatus, new recordations of said physiological parameter are made in association with accurate time-of-day signals.

8. A method of long-term monitoring of the blood pressure of a patient to provide a compact, portable record of said activity comprising the steps of:

sensing and measuring said blood pressure of said patient at a predetermined time;

generating a time-of-day signal;

storing said measured blood pressure and time-of-day signal in a portable solid state memory as a singular data event;

inhibiting said steps of sensing and measuring, generating and storing for a predetermined interval;

resequencing through said steps of sensing and measuring, generating, storing and inhibiting to place a plurality of said data events in said portable solid state memory over a long-term period of time, the number of said steps of resequencing corresponding to the number of data events stored in said portable solid state memory said long-term monitoring equalling at least on day,

selectively ceasing said resequencing upon a low power condition; and

continuing said steps of generating, storing and inhibiting said time-of-day signal during said low power condition,

whereby said compact portable record is provided in said solid state memory during said long-term monitoring.