Method and apparatus for measuring heart-related parameters and deriving human status parameters from sensed physiological and contextual parameters

Abstract

A monitor device and associated methodology are disclosed which provide a self contained, relatively small and continuously wearable package for the monitoring of heart related parameters, including ECG. The detection of heart related parameters is predicated on the location of inequipotential signals located within regions of the human body conventionally defined as equivalent for the purpose of detection of heart related electrical activity, such as on single limbs. Amplification, filtering and processing methods and apparatus are described in conjunction with analytical tools for beat detection and display.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application is a continuation of co-pending U.S. application Ser. No. 10 / 940,889 entitled Method and Apparatus for Measuring Heart Related Parameters filed Sep. 13, 2004, which claims the benefit of U.S. Provisional Application Ser. No. 60 / 502,764, filed Sep. 12, 2003; U.S. Provisional Application Ser. No. 60 / 510,013, filed Oct. 9, 2003; and U.S. Provisional Application Ser. No. 60 / 555,280, filed Mar. 22, 2004.BACKGROUND[0002]1. Field[0003]The present invention relates to a method and apparatus for accurately measuring heart related parameters from within a conventionally defined equivalence region of the human body. More particularly, a method and apparatus is disclosed for measuring an ECG signal and other heart related parameters such as heart beats or heart rate from a single limb of the human body. Most specifically, the heart related parameters are taken from the upper left or right arm.[0004]2. Description of the Related Art[0...

AI Technical Summary

Benefits of technology

"The patent describes a small and wearable monitor device for monitoring heart-related parameters, such as ECG, in real-time. The device is designed to be comfortable and unobtrusive, with a simple and flexible housing that can be worn for extended periods of time. It is designed to continuously provide a quality signal or data record and reduce interference with the wearer's daily activity. The device is easy to put on and take off without needing extensive skin preparation. It includes sensors that can detect various parameters of the individual, such as respiration, temperature, and body conductance, and a processor that receives and generates data from the sensors. The device can also be used in conjunction with an external central monitoring unit. Overall, the invention provides a self-contained, comfortable, and effective solution for monitoring heart-related parameters."

Problems solved by technology

Such devices, while highly accurate, are very expensive and cumbersome and thus do not lend themselves well to ambulatory or long term uses such as in a free living environment.

The physical bulk and inconvenient accessories of this device restricts its continuous use to a relatively short time frame.

Consequently, the sensors are not easily interchanged and may limit physical or hygienic activity.

Holter monitors are relatively expensive and for the reasons listed above, are not comfortable for long term and / or active wear situations.

While some success with respect to longer term wearability and comfort is achieved, these loop monitor devices are still inconvenient for everyday use, and include lead wires from the device, snap on sensors affixed to the body by adhesives which require daily skin preparation and periodic re-alignment of the sensors to the original positions.

Implantable loop recorders have also been developed, which provide similar functionality, with the attendant inconvenience and risks associated with an invasive implant.

This device is not utilized for continuous monitoring, and has memory capability for only a limited number of event records.

Chest strap monitors of this type, while promoted for use in exercise situations, are not particularly comfortable to wear and are prone to lift off of the body during use, particularly when the wearer lies on his or her back.

Such watches, while comfortable to wear, only make measurements when touched in this particular manner and thus are not suitable for monitoring ECG and heart rate continuously over long periods of time or while conducting everyday activities such as eating, sleeping, exercising or even keyboarding at a computer.

Moreover, the traditional model rejects the measurement of the action potential from two locations on the same limb.

Another significant shortcoming of ambulatory devices is electrical noise.

A significant noise problem exists in that environment, including the heart action of the mother, as well as the significant noise and distortion caused by the fetus' location within a liquid sac inside the mother's abdomen.

The system, like many of the prior art, is unconcerned with the wearability of the monitoring device or the ability to continuously monitor the subject over a long period of time.

None of the above systems identified above combine wearability and accuracy in a compact device.

Although there are some examples in the prior art that recognize the possibility of inequipotential pairs within a single equivalence region, that the teachings of the prior art fail to utilize these pairs for obtaining a viable signal.

There are several barriers to the ability to utilize these signals from unconventional locations, including the small amplitude of the signal, which can be less than one tenth of the signal measured at most conventionally placed electrode locations, the high amount of noise with respect to that signal, as well as the significant effort and risk required to overcome limitations in accuracy, amplitude, and noise obtained from unconventional placements.

Additionally, what is lacking in the art is the ability to combine the continuous monitoring of the heart related parameters with a device which can detect, identify and record the physical activities of the wearer and correlate the same to the heart related parameters.

Each of these factors increases the wearability of the item and therefore increases the compliance of the wearer with the need for long term and continuous wear.

Images