WO2023244199A1

WO2023244199A1 - An armband to locate an artery for opening vascular access

Info

Publication number: WO2023244199A1
Application number: PCT/TR2023/050522
Authority: WO
Inventors: Mustafa İlker BEYAZ
Original assignee: Antalya Bilim Universitesi Rektorlugu
Priority date: 2022-06-14
Filing date: 2023-06-04
Publication date: 2023-12-21
Also published as: TR2022009838A2

Abstract

The invention is about an armband comprising LEDs, photodiodes, and a microcontroller to locate an artery for opening vascular access. The armband does not comprise any image processing technique or tools.

Description

AN ARMBAND TO LOCATE AN ARTERY FOR OPENING VASCULAR ACCESS

TECHNICAL FIELD

BACKGROUND

Medical personnel often experience difficulties when locating a patient’s artery for taking blood samples or opening vascular access. Accordingly, they may have to insert the needle multiple times, which results in a high level of discomfort for the patient. To eliminate this problem especially for the children and elderly people, several systems to precisely locate arteries have been developed. However, complex image processing technologies and expensive hardware are being used in such systems.

LIST OF FIGURES

Figure 1 - The general view of the invention

The numbering on the figures are:

1 . Arm band

2. LED-Photodiode-LED group

3. Microcontroller

4. Battery

5. Opening

DETAILED DESCRIPTION OF THE INVENTION

This invention is about an arm band (1 ) to locate arteries comprising LEDs, photodiodes, and a microcontroller (3). The invention further comprises a rechargeable battery (4) for power, and does not involve any image processing techniques. The invention allows people to take their own blood sample without going to healthcare facilities due to its simple structure.

The invention comprises an arm band (1 ) and electronic components on it to be placed on brachial artery around the elbow. Brachial artery means inside artery in Latin. These arteries are located on the front and back side of the elbow. Therefore, stethoscopes are placed on these arteries during blood pressure measurements.

In the middle of the arm band (1 ) an opening (5) is comprised, where a LED- photodiode-LED groups (2) are lined up along both sides of this opening (5). The aforementioned LED-photodiode-LED group (2) further comprises two LEDs and a photodiode. While one of the LEDs is providing light inside the tissue for signal generation, the other LED is used to display the result to the user. The photodiode is used to measure the reflected light generated by the first LED.

The LED that emits light into the tissue in the LED-photodiode-LED group (2) described above, provides a light with wavelength between 650-940 nm. The reflected light is detected and measured by the photodiodes. This technique is called photoplethysmography (PPG), which is used to optically monitor the volumetric blood changes in the peripheral blood circulation. Since the hemoglobin in the blood absorbs light at this wavelength scale, the light reflection from the tissue decreases when the blood pulse passes below the LED-photodiode-LED group (2). Accordingly, the blood pulse can be monitored through the reduction in the photodiode response.

The microcontroller (3) on the arm band, samples the photodiode signal for five seconds at a rate of 100 samples per second. The microcontroller (3) then clears out the photodiode signal from noise using a digital band pass filter having cutoff frequencies of 0.5 Hz and 3 Hz. In other words, signals with frequencies below 0.5 Hz and above 3 Hz are eliminated, while the signals with frequencies between 0.5 Hz - 3 Hz that correspond to 30 - 180 beat per minute heart rate are obtained. Next, maximum and minimum signal levels from all the photodiodes are revealed using a peak detection algorithm embedded in the microcontroller (3). The artery is located below the photodiode that provides the highest difference between the maximum and minimum peak levels. The two such photodiodes on the two sides of the opening (5) correspond to the two points in perfect alignment with the artery. Accordingly, the needle should be inserted in the middle of these two photodiodes in the opening (5). The LED in the LED-photodiode-LED group (2), which is used to display the result to the user, is lit by the microcontroller (3) so that the user knows where exactly those two photodiodes are, and where the needle should be inserted.

Claims

1 - An arm band (1 ) to locate the artery location for opening vascular access on the brachial artery around the elbow characterized by comprising;

- LED-photodiode-LED (2) groups,

- A microcontroller (3),

- A battery (4),

- An opening (5).

2- The arm band (1 ) to locate the artery location for opening vascular access on the brachial artery around the elbow according to Claim 1 characterized by the LED- photodiode-LED groups are placed along the two sides of the opening (5).

3- The arm band (1 ) to locate the artery location for opening vascular access on the brachial artery around the elbow according to Claim 2 characterized by the LED- photodiode-LED group (2) further comprises two LEDs and a photodiode, where one LED provides light into the tissue, and one LED displays the result to the user.

4- The arm band (1 ) to locate the artery location for opening vascular access on the brachial artery around the elbow according to any claim above characterized by the LED in the LED-photodiode-LED group (2), that emits light into the tissue, further comprises a wavelength between 650-940 nm.

5- The arm band (1 ) to locate the artery location for opening vascular access on the brachial artery around the elbow according to any claim above characterized by comprising the photodiode in the LED-photodiode-LED (2) group, that obtains the blood pulse signal by monitoring the reduction in the reflected light emitted into the tissue by the LED.

6- The arm band (1 ) to locate the artery location for opening vascular access on the brachial artery around the elbow according to Claim 1 characterized by comprising the microcontroller (3) further comprising the functions below;

- Sampling photodiode signals at a rate of 100 samples/second for 5 seconds,

- Including a digital band pass filter with cutoff frequencies of 0.5 Hz - 3 Hz to processes the 500 photodiode signal data and clear out the noise, - Including a peak detection algorithm to detect the maximum and minimum signal levels obtained from all the photodiodes,

- Determining the photodiode with the highest difference between the maximum and minimum signal levels,

- Showing the user where the needle should be inserted by lighting the LED faced to the user in the LED-photodiode-LED group (2). - A method to locate the artery location for opening vascular access on the brachial artery around the elbow with the arm band (1 ) to locate the artery location for opening vascular access on the brachial artery around the elbow according to any claim above characterized by comorising the steps below;

- Emitting a light at a wavelength between 650-940 nm using a LED in a LED-photodiode-LED group (2),

- Measuring the reflected light using photodiodes,

- Collecting photodiode signal data at a rate of 100 samples/second for 5 seconds using the microcontroller (3) on the arm band (1 ),

- Processing and clearing out the noise on the 500 photodiode signal data using a digital band pass filter with cutoff frequencies of 0.5 Hz - 3 Hz that is coded in the algorithm on the microcontroller (3),

- Detecting the maximum and minimum peak signal levels for all the photodiodes with a peak deteection algorithm,

- After determining the two photodiodes on the two sides, showing the user where the needle should be inserted by lighting the corresponding LEDs faced to the user in the LED-photodiode-LED group (2).