Device and system that identifies cardiovascular insufficiency

• US 7,678,057 B2
• Filed: 03/24/2006
• Issued: 03/16/2010
• Est. Priority Date: 03/24/2005
• Status: Active Grant

• Current Assignee: Intelomed, Inc., University of Pittsburgh of The Commonwealth System of Higher Education
• Original Assignee: Intelomed, Inc., University of Pittsburgh of The Commonwealth System of Higher Education
• Inventors: Berkow, Jan, Pinsky, Michael, Puyana, Juan Carlos
• Primary Examiner(s): Nasser; Robert L
• Assistant Examiner(s): D'ANGELO, MICHAEL J
• Application Number:
  US11/388,661
• Publication Number:
  US 20070088222A1
• Time in Patent Office: 1,453 Days
• Field of Search: 600/485, 600/509, 600/300, 600/324
• US Class Current: 600/481
• CPC Class Codes: A61B 5/0002 Remote monitoring of patients using telemetry, e.g. transmission of vital signals via a communication network A61B5/07 takes precedence; transmission systems for measured values G08C; transmission H04B; transmission of digital information H04L; wireless communication networks H04W
• 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: A61B 5/02416 using photoplethysmograph signals, e.g. generated by infrared radiation A61B5/14552 takes precedence
• CPC Class Codes: A61B 5/412 Detecting or monitoring sepsis

Abstract

In an embodiment, the present invention provides a device that identifies cardiovascular dysfunction of a subject. The claimed device comprises a controller, a transducer, and a processor. The controller initiates collection of a plurality of data related to a physiological condition. The transducer collects data over a plurality of cycles and transfers the data to the processor, which reduces the received data signal into an output using a novel formula. In an example the data correlate with data that are directly related to cardiovascular dysfunction but that are of limited use.

Claims

1. A non-invasive device that identifies volume insufficiency in a patient, comprising:

a. a transducer that records a pulse density signal from said patient during at least one respiratory cycle prior to administration of a cardiovascular volume load and during at least one respiratory cycle following administration of said cardiovascular volume load, wherein each respiratory cycle includes a plurality of cardiovascular subcycles;

b. a controller that controls said transducer to initiate said record of said pulse density signal, said controller comprising at least one of the following;

i. a manual or an automated switch;

ii. a plurality of software rules;

or

iii. a combination thereof;

c. an activator that activates said cardiovascular volume load; and

d. a processor that is configured to filter said pulse density signal to capture a maximum and minimum data point in each cardiovascular subcycle and to calculate a percent deviation of said pulse density signal across all of said cycles, said percent deviation reflecting a volume status of said patient, said percent deviation being calculated according to the following formula;

percent deviation_{data signal}=(Pmean_max−

Pmean_min)/[(Pmean_max+Pmean_min)/2]×

100,

wherein percent deviation_{data signal} is a variation in said pulse density signal recorded by said transducer prior to said cardiovascular volume load and following said cardiovascular volume load,

wherein Pmean_max is a maximum mean value of said pulse density signal recorded during all of said cycles,

wherein Pmean_min is a minimum mean value of said pulse density signal recorded during all of said cycles,

wherein each said mean value of said pulse density signal is calculated for each said cardiovascular subcycle (c), as follows;

Pmean_c=Pmax_c+Pmin_c/2, wherein Pmax_c is a maximum pulse density signal in a given subcycle (c) and Pmin_c is a minimum pulse density signal in said given subcycle (c).

2. A device as in claim 1 wherein said device is portable and/or wearable.

3. A device as in claim 1 wherein said activator is at least one of the following:

a. a volume of fluid;

b. a pharmacologic agent;

c. a physical maneuver;

d. a mechanical ventilation;

e. a manual or an automated switch;

f. a motion sensor;

g. a compression device;

or

h. a combination thereof.

4. A device as in claim 3 wherein said physical maneuver is raising a leg of said patient by about 30%, a compression of a part of said patient'"'"'s body, or a change in a physical position of said patient.

5. A device as in claim 3 wherein said pharmacologic agent is at least one of:

a. a vasodilator;

b. a vasoconstrictor;

c. a vasoactive agent;

or

d. a combination thereof.

6. A device as in claim 1 wherein said processor is further configured to generate an output that is selected from the group consisting of a data set, said pulse density signal, an interface, an interpretation, and a suggested treatment or protocol.

7. A device as in claim 6 wherein said output is graphical, numerical, or textual.

9. A device as in claim 1 wherein said transducer is a photoplethysmographic device.

10. A device as in claim 1 wherein said device is an inflatable cuff.

8. A device wherein said output is displayed on at least one of the following:

a. a remote display;

b. a handheld display;

c. a display on said device;

d. a display integrated with an interface;

or

e. a combination thereof.

11. A method of using a device to identify volume insufficiency in a patient comprising the steps of:

a. initiating a recording of a pulse density signal by a transducer during at least one respiratory cycle prior to administration of a cardiovascular volume load and during at least one respiratory cycle following administration of said cardiovascular volume load;

b. activating administration of said cardiovascular volume load;

c. filtering said pulse density signal to capture a maximum and minimum data point in each cardiovascular subcycle and to calculate a percent deviation of said pulse density signal across all of said cycles, said percent deviation reflecting a volume status of said patient, said percent deviation being calculated according to the following formula;

percent deviation_{data signal}=(Pmean_max−

Pmean_min)/[(Pmean_max+Pmean_min)/2]×

100,

wherein percent deviation_{data signal} is a variation in said pulse density signal recorded by said transducer prior to said cardiovascular volume load and following said cardiovascular volume load,

wherein Pmean_max is a maximum mean value of said pulse density signal recorded during all of said cycles,

wherein Pmean_min is a minimum mean value of said pulse density signal recorded during all of said cycles,

wherein each said mean value of said pulse density signal is calculated for each said cardiovascular subcycle (c), as follows;

Pmean_c=Pmax_c+Pmin_c/2, wherein Pmax_c is a maximum pulse density signal in a given subcycle (c) and Pmin_c is a minimum pulse density signal in said given subcycle (c),

d. converting said pulse density signal to an output; and

e. analyzing said output to identify a volume status of said patient.

12. A method as in claim 11 further comprising the step of using output to:

a. monitor said patient either remotely or non-remotely;

b. manage said patient;

c. institute a treatment protocol for said patient;

or

d. a combination thereof.