AU2020100418A4

AU2020100418A4 - Wearable calf stimulator with velocimetric sensor for increasing vascular blood flow

Info

Publication number: AU2020100418A4
Application number: AU2020100418A
Authority: AU
Inventors: Mohamed Salih; Ritesh Warty
Original assignee: Individual
Current assignee: Individual
Priority date: 2020-03-19
Filing date: 2020-03-19
Publication date: 2020-09-10
Anticipated expiration: 2028-03-19

Abstract

Title: Wearable calf stimulator with velocimetric sensor for increasing vascular blood flow Authors: Ritesh Warty, Mohamed Salih Abstract: The invention provides an apparatus and method for stimulating the muscles of the calf (gastrocnemius and soleus) to reduce the risks associated with venous stasis, for example thrombus formation or venous ulceration. This is performed by embedding a stimulator that is designed to emit biphasic, square-wave pulses at safe and controllable frequencies and amplitudes within an article of clothing, such as a sock or stocking, and increasing venous blood flow which will be monitored though the incorporation of a sensor that enables blood velocimetry.

Description

Editorial Note

2020100418

There are three pages of description only

Description:

Background:

Venous stasis occurs when blood flow in the veins becomes too slow for effective return of blood to the heart. Often, it occurs in the legs and can be caused by conditions such as chronic venous insufficiency, heart failure, or increased sedentary behaviour such as flying, sitting for extended durations such as at work, and hospitalisation. A common effect of venous stasis is thrombus formation which could be in the form of a deep vein thrombus (DVT) or pulmonary embolism (PE). Another common effect is venous ulceration. To try and prevent these severe events from occurring, clinicians recommend walking, calf exercises, and intermittent pneumatic compression via serial compression devices. In some cases, such as patients who suffer from chronic venous insufficiency, management may include conservative treatments such as massage therapy, compression stockings or serial compression devices; whilst surgical measures may be employed in some other cases.

Neuromuscular electrical stimulation (NMES) is a technological medium that elicits muscular contraction using electrical impulses. The introduction of electrical pulse trains into the body has demonstrated potential in muscle rehabilitation, strength training, post-event recovery for athletes, and evaluating neuromuscular function. The use of NMES in immediate post-surgical stimulation of calf muscles for prevention of venous thrombosis has become an FDA-approved indication for prescribed existing NMES devices, such as the Veinoplus. This provides another area of opportunity for the technology as creation of a wearable that can be targeted to at-risk members of the general public can assist in reducing the incidence rate of cardiovascular disease-related events.

To do this, a novel electrical stimulation apparatus which is embedded within specially designed clothing that may then be worn by the user is presented. To add a second layer of novelty, the use of a sensor capable of measuring venous blood flow velocity is included within the apparatus to provide a monitoring function that can also potentially enable automated control based on thresholds derived from blood velocity and timing.

Summary of the Invention:

The invention may provide, in a broad aspect, a specially designed apparatus for increasing venous blood velocity to reduce the risk of venous stasis-related complications through the use of controlled electrical impulses.

In one embodiment, the impulse generator and associated electronics are embedded within a specially designed article of clothing that will house and protect the circuitry from damaging factors, such as fluids; whilst ensuring adequate electrode contact with the user's skin.

In one embodiment, the electrodes used to transmit the electrical impulses are either of the standard disposable variety and can be attached to the clothing or the preferred conductive textile electrodes that have been embroidered into the fabric of the clothing itself.

In one embodiment, the embedded circuitry includes a velocimetry sensor that can analyse blood flow characteristics and relay that information to the user or even drive the control of the device using data analytics and thresholds related to blood velocity and prescribed stimulation regimen.

In one embodiment, the electronics component further consists of a wireless receiver and microcontroller to enable activation/deactivation of stimulation via a paired user device such as a smartphone, as well as provide control of pulse frequency and amplitude.

Detailed Description of Embodiments:

The present invention is a calf stimulator of wearable design for preventing the adverse events associated with venous stasis in at-risk members of the general population. When worn and activated, the device introduces safe electrical impulse trains into the body to initiate muscular contraction with the overall aim of increasing venous blood flow. The stimulation regime may be determined through future research or based upon clinician recommendation.

Fabrication of the wearable is performed by embedding the circuitry within an article of fitted/compressive clothing, such as a sock or stocking, using materials that are safe to be washed and can protect the circuitry from any damage that may occur in the product life span. There is potential for this wearable to be customised to the patient's body to ensure an adequate contact between the electrodes and appropriate skin areas. These skin areas are as considered for existing clinical tests and procedures, such as the nerve conduction study or lower limb electromyography.

Embedded within this wearable is the circuitry required to directly stimulate the muscles of the surrounding region (namely, the gastrocnemius and soleus) or a nerve responsible for calf innervation. This circuitry is composed of various sub-circuits which include the power supply (such as replaceable batteries), pulse generator, output modulation circuit, and electrodes. The electrodes may be standard disposable electrodes or the preferred conductive textile electrodes embroidered into the clothing. A Bluetooth Low-Energy (BLE) receiver, which can be paired with an external transmitter, is connected to a micro-controller to moderate activation/deactivation and output frequency and amplitude.

The output of this circuit, as mentioned prior, is controllable. The output currents may be set between 0 and 80 mA and the frequency of the pulses set to 0.8-100 Hz. Contained within the output modulation circuit is a voltage regulator which restricts the output to a maximum of 3.3V.

Blood velocimetry typically uses doppler techniques to measure the flow of blood through the vein. Other methods such as photoplethysmography can be used to derive the velocity as well. The use of doppler however has the advantage of controlling the depth of measurement and is therefore implemented here. Through the application of such technology, the device will monitor the blood flow at regular intervals as set by the clinician/trained user.

There is also the configuration that may be activated to enable "Sensor-driven Stimulation". In this mode, when the velocity drops below a certain threshold, the sensor will trigger the controller to start releasing impulses into the body for a certain duration. However, this mode will have precautionary measures implemented to prevent injury and/or over-stimulation. Hence, long-term application can be achieved as the therapy is only delivered when required and the unit can save energy and enable the user to focus on other tasks.

The circuitry associated with the measurement of blood flow velocity will be embedded with the clothing and designed such that the sensor is in the appropriate position to obtain accurate measurements.

After application (i.e. being worn), control of this device is performed externally and can be driven manually by the user or by the velocimetric circuitry. This is done using a BLE transmitter which can relay instructions to the microcontroller, via the receiver, regarding pulse frequency and intensity. Activation/deactivation of the circuit is also performed using this controller, which may be a smartphone or another type of device capable of user interfacing. The incorporation of controlled regimen may be designed and implemented through this controller for enhanced treatment plans.

Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognise that changes may be made in form and detail without departing from the spirit and scope of the invention.

Claims

Editorial Note 2020100418 There is one page of claims only Claims:

1) A customisable apparatus embedded in fitted/compressive clothing, such as socks or stockings, for initiating muscular contractions in the calf to increase venous blood velocity and prevent the complications associated with venous stasis. This apparatus contains an embedded electrical stimulator that emits biphasic, square-wave pulses at a safe frequency and amplitude.

2) The apparatus described in Claim 1 may employ the use of conductive textile electrodes that are embroidered into the clothing.

3) Control of the stimulation duration, blood flow threshold, pulse frequency, and amplitude in the stimulator of Claim 1 is performed by a micro-controller in conjunction with a wireless receiver that is paired with an external controller device.

4) The apparatus in Claim 1 employs a blood velocimetry sensor and the accompanying hardware and software components to accurately display, monitor and measure blood velocity in the lower limb/s of the user.

) The blood velocimetric circuitry described in Claim 4 may be used to drive the stimulation regimen.