BACKGROUND OF THE INVENTION

1. Technical Field

The present invention relates to a carotid physiological parameter monitoring system. More particularly, the invention is a physiological parameter monitoring system for monitoring carotid stenosis.

2. Description of Related Art

The carotid arteries are the main source arteries that supply blood to the brain but are also the predilection sites for atherosclerosis. Carotid arteriosclerosis may lead to brain ischemia or even a severe stroke and is therefore an important risk factor of cerebrovascular disease. Moreover, the presence and degree of carotid arteriosclerosis may reflect to a certain extent the presence and degree of arteriosclerosis of the other major arteries. The carotid arteries are shallow, easy to detect, and hence a clinical window through which to discover arteriosclerosis.

A stroke is a cerebrovascular disease that stems from insufficient blood supply to the brain and that causes damage to the central nervous system, occurring typically in those who are 60 to 70 years old. Apart from such risk factors as hypertension, diabetes, hyperlipidemia, smoking, and family history, atherosclerosis is the most common cause of ischemic strokes. Literature has shown that carotid stenosis-related occlusion accounts for about 20% of the cases of atherosclerosis, hypertension-related lacunar infarct about 20%, occlusion attributable to atrial fibrillation-related arrhythmia 25%, and occlusion of unknown causes 30%.

Carotid stenosis and its symptoms aggravate over time. It can be known from the above that the detection and quantitative assessment of carotid stenosis are of paramount clinical importance to the prevention of strokes. Methods conventionally used to diagnose carotid stenosis include carotid angiography, ultrasound scanning, magnetic resonance angiography (MRA), and so on.

BRIEF SUMMARY OF THE INVENTION

The conventional methods for diagnosing carotid stenosis are time-consuming, have their respective limitations, and are hence unsuitable for fast screening or real-time monitoring. For example, due to the cranium, only a limited portion of the carotid arteries is clinically detectable by ultrasonography. While the detection area can be increased by using an ultrasound device whose sound waves can penetrate the cranium, the detection ability of such a device is still limited, not to mention that it takes at least twenty minutes to complete one examination. Angiography has a false negative rate as high as about 40%, which was found by a comparison with the result of carotid endarterectomy. That is to say, angiography is prone to diagnostic errors and therefore often fails to provide an early diagnosis of carotid stenosis. Moreover, the contrast agent required to be injected into a patient undergoing angiographic examination may cause allergic reactions in the patient. MRA allows blood flow velocity to be observed with ease, but it is difficult to inspect the anatomical structures of blood vessels with MRA as precisely as with the conventional angiography. In addition, both angiography and MRA require a longer examination time than ultrasound scanning.

One objective of the present invention is to provide a carotid physiological parameter monitoring system that is suitable for fast screening and can monitor the degree of carotid stenosis in real time. The carotid physiological parameter monitoring system of the present invention comprises: an electrocardiographic (ECG) monitoring device, a carotid pulse wave detector, and at least one controller. The ECG monitoring device is disposed on a user's left and right wrists or on the user's chest, wherein the ECG monitoring device comprises a device body and a plurality of electrodes provided on the device body to obtain ECG waveforms. The carotid pulse wave detector is disposed on the user's neck at a position corresponding to the user's carotid arteries, wherein the carotid pulse wave detector comprises at least one sensor for obtaining carotid pulse waveforms. The controller is provided in at least one of the ECG monitoring device, the carotid pulse wave detector, and a mobile device, wherein the controller is configured to obtain a carotid physiological parameter of the user by calculating with the ECG waveforms and/or the carotid pulse waveforms.

In a preferred embodiment, the ECG monitoring device, the carotid pulse wave detector and the mobile device are connected via wireless transmission.

In a preferred embodiment, the carotid physiological parameter(s) includes/include carotid pulse wave velocity or carotid blood pressure.

In a preferred embodiment, the carotid pulse wave detector is any measuring device selected from the group consisting of a Doppler radar, a pressure sensor, an acoustic wave sensor, an ultrasound sensor, and a photoplethysmographic (PPG) sensor.

In a preferred embodiment, the sensor of the carotid pulse wave detector is disposed at a pulse measuring point on a user's neck, wherein the pulse measuring point is a point in a line segment defined as follows: the line segment starts from a starting point (or 0 cm position) defined as a point that is to the left or right of, and horizontally spaced apart by 3±0.3 cm from, the peak of the thyroid cartilage, and the line segment extends from the starting point (or 0 cm position) for 4 cm along a direction that extends distally at an angle of 135 degrees with respect to the horizontal direction.

In a preferred embodiment, the device body includes a left wrist-mounted device and a right wrist-mounted device; the electrodes comprise a right electrode (RA), a left electrode (LA), and a ground electrode (G); the right electrode (RA) is provided at the right wrist-mounted device; the left electrode (LA) is provided at the left wrist-mounted device; and the ground electrode (G) is provided in the left wrist-mounted device or the right wrist-mounted device and is adjacent to a lateral side of a corresponding one of the right electrode (RA) and the left electrode (LA).

In a preferred embodiment, the device body includes a chest-mounted device; the electrodes comprise a right electrode (RA), a left electrode (LA), and a ground electrode (G); the right electrode (RA) and the left electrode (LA) are provided on a right side and a left side of the chest-mounted device respectively; and the ground electrode (G) is provided alongside the right electrode but is not located between the right electrode and the left electrode.

In a preferred embodiment, the chest-mounted device is attached to a user's chest, the right electrode (RA) and the ground electrode (G) are horizontally arranged in an area higher than and to the right of the user's xiphoid process (from the user's point of view), and the left electrode (LA) is higher than and to the left of the user's xiphoid process (also from the user's point of view) and is horizontally aligned with the right electrode (RA) and the ground electrode (G).

In a preferred embodiment, the chest-mounted device is attached to a user's chest, the right electrode (RA) and the ground electrode (G) are horizontally arranged in an area higher than and to the right of the user's xiphoid process (from the user's point of view), and the left electrode (LA) is higher than and to the left of the user's xiphoid process (also from the user's point of view) and is lower than the right electrode (RA) and the ground electrode (G).

In a preferred embodiment, the chest-mounted device is attached to a user's chest, the right electrode (RA) and the ground electrode (G) are vertically arranged in an area higher than and to the right of the user's xiphoid process (from the user's point of view), with the right electrode (RA) higher than the ground electrode (G), and the left electrode (LA) is higher than and to the left of the user's xiphoid process (also from the user's point of view) and is horizontally aligned with the ground electrode (G).

Comparing to the conventional techniques, the present invention has the following advantages:

1. The carotid physiological parameter monitoring system of the present invention is configured to monitor a user's carotid physiological parameter(s) (which may include carotid pulse wave velocity or carotid blood pressure) in real time so that the user as well as a medical professional can use the system for fast screening or to determine the user's cardiovascular health and degree of cardiovascular disease.

2. The carotid physiological parameter monitoring system of the present invention is non-invasive during use and is not subject to the limitations of the cranium when disposed on the user's neck.

3. The carotid physiological parameter monitoring system of the present invention uses a controller configured for wireless transmission and therefore can be disposed on a user's neck and left and right wrists (or on the user's neck and chest) without the drawbacks associated with wired transmission, such as the physical discomfort caused by wires running over a user's body and unstable signal transmission (if not interruption of the ongoing monitoring process) resulting from the wires being caught.

