OMRON All for Healthcare

2016.04.18

Omron Healthcare develops the world's first technology to enable continuous beat-by-beat blood pressure monitoring with a wrist-attached device

Tokyo, Japan--Omron Healthcare Co. Ltd. (Headquarters: Muko, Kyoto; President and CEO: Isao Ogino) has developed a continuous, noninvasive beat-by-beat blood pressure monitoring technology. This technology, the first of its kind in the world, uses Omron's proprietary pressure sensor to apply pressure in a way to partially flatten the radial artery, thus enabling measurement of blood pressure for each heartbeat simply by attaching the monitor unit on the wrist.

Omron Healthcare's mission is "to help realize healthy and comfortable lives for people around the world." Living up to this mission, Omron Healthcare already began promoting the idea of blood pressure monitoring at home way back in the 1970s, when blood pressure could only be measured at a medical facility. Since then, the company, in cooperation with medical professionals, has been committed to establishing blood pressure management at home as a common practice in society. Presently, Omron home-use blood pressure monitors are available in more than 110 countries worldwide.

Nonetheless, the widespread occurrence and increasing severity of high blood pressure in patients creates a high possibility of cerebral or cardiovascular events such as strokes and myocardial infarction. In fact, these events are the leading cause for Japanese people requiring long-term nursing care, accounting for nearly one-fourth (22%) of all causes.1 The demand for long-term nursing care diminishes the quality of life for both the patient and the patient's family, while also contributing to soaring medical expenses.

To help cope with these social issues, Omron Healthcare launched a new endeavor toward the aim of realizing "zero cerebral and cardiovascular events."

The heart beats about 100,000 times in a day, and blood pressure varies from beat to beat. Above all, high blood pressure during the night or early morning, as well as a sharp rise in blood pressure, is known to increase the risk of developing cerebral or cardiovascular events.

However, the oscillometric method2 most commonly used in home-use blood pressure monitors today requires temporarily blocking off the flow of blood by compressing the entire blood vessel of the upper arm or wrist with a cuff. As a result, oscillometric monitoring equipment is unable to continuously measure blood pressure in a noninvasive manner, making it impossible to detect rapid blood pressure changes--a high-risk factor.

To achieve zero cerebral/cardiovascular events, Omron Healthcare realized the importance of predicting the risk of developing such events by continuously monitoring blood pressure and detecting high-risk blood pressure changes. This will help prevent cerebral/cardiovascular diseases. Based on this awareness, Omron Healthcare has strived to achieve beat-by-beat blood pressure monitoring. This effort has led to the recent development of the technology that employs tonometry3 to enable easy measurement of blood pressure for each heartbeat with a wrist-type unit.

Tonometry is a method of measuring blood pressure for each heartbeat by pressing a pressure sensor over the flattened surface of the radial artery close to the skin of the wrist. With conventional tonometric monitoring, it was necessary to check the blood pressure value for each heartbeat detected at the wrist against the blood pressure reading obtained at the upper arm, thus requiring costly large-sized equipment and a complicated monitoring procedure.

To address this problem, it was necessary to develop a technology that enables monitoring of beat-by-beat blood pressure through a wrist-type device. To make this happen, Omron Healthcare developed its own pressure sensor jointly with Omron Corporation. The sensor consists of an array of 46 sensing devices, leveraging Omron's core competencies in semiconductor, MEMS (ultrahigh-precision fabrication) and IC sensing technologies. These technologies are combined with Omron Healthcare's expertise in blood pressure monitoring cultivated over many years. Furthermore, a special mechanism was constructed for detecting if the sensor correctly applies pressure on the artery, and automatically adjusting the angle of the sensor if necessary. This has enabled a wrist-type unit to easily measure blood pressure for each heartbeat.

Omron Healthcare has already completed a prototype device capable of continuously monitoring blood pressure for a patient asleep at night, and launched a clinical research project using this prototype in March. Easy measurement of blood pressure for each heartbeat in turn enables the detection of abrupt changes in blood pressure as well as the assessment of their degree, pattern, and frequency. It also makes it possible to detect a drop in a natural function of the human body that keeps blood pressure in a normal range. By using this information of blood pressure changes, we aim to detect high-risk blood pressure increases for each patient and predict his/her risk of developing cerebral or cardiovascular events. This will allow Omron Healthcare to contribute to more reliable and efficient diagnosis and treatment of hypertension, which is essential for reducing the development of cerebral or cardiovascular events. Going forward, we will strive to further improve the accuracy of monitoring and usability and develop products for clinical research, with the aim of obtaining approval required by the Pharmaceuticals and Medical Devices Act.

Main Features
1. Omron proprietary pressure sensor enables beat-by-beat blood pressure monitoring through a wrist-type unit

Omron Healthcare's new pressure sensor is designed to measure blood pressure for each heartbeat simply by attaching the monitor unit on the wrist. This development combined Omron's core sensing technology with Omron Healthcare's blood pressure monitoring know-how accumulated over many years. The new sensor incorporates an array of 46 pressure sensing devices. By combining Omron's semiconductor, MEMS and IC sensing technologies, Omron Healthcare was able to complete a sensor dedicated to radial artery tonometry for blood pressure measurement that delivers the sensor precision required for accurate monitoring.

2. Automatic sensor angle adjustment mechanism ensures proper pressure application on the artery

To obtain accurate radial artery pressure readings, the pressure sensor must be positioned over the flattened surface of the radial artery. However, the wrist structure varies from person to person, and interference of the radial bone and tendon located close to the radial artery made it difficult to apply pressure on the flattened surface of the artery. With conventional equipment, only one sensor was used and applied to a single part of the artery, thus it was difficult to tell if the sensor was applied correctly.

To cope with these problems, Omron Healthcare built a mechanism to automatically adjust the sensor angle to match each patient by positioning two pressure sensors and obtaining pressure data from each of them. This made continuous beat-by-beat monitoring of blood pressure possible using a wrist-type monitor alone.

Omron Healthcare's technology adopted for AMED's ICT-based Diagnosis-Assisting Technology Research and Development Project

An R&D project using Omron Healthcare's pressure sensor, conducted jointly by Jichi Medical University and Kyushu University, was adopted by the Japan Agency for Medical Research and Development (AMED) as one of its ICT-based Diagnosis-Assisting Technology Research and Development Projects. As part of this project, clinical research was launched in March 2016.

Title of R&D project:
Development of Cardiovascular Diagnosis-Assisting Technology via a Wearable Monitor

Development task assigned to each party of the joint development project:
- Omron Healthcare Co., Ltd. (representative)
Development of a wearable continuous instant blood pressure monitor and a cardiovascular diagnosis-assisting system

- Jichi Medical University
Assessment of cardiovascular disease risk by a blood pressure surge evaluation algorithm

- Kyushu University
Assessment of cardiovascular disease risk by a cardiovascular homeostasis evaluation algorithm

1 Diseases causing the need for long-term nursing care in Japan
(According to the 2013 Comprehensive Survey of Living Conditions conducted by the Ministry of Health, Labor and Welfare.)

2 Oscillometric method
With the oscillometric method, the cuff is first inflated to compress a patient's upper arm or wrist for occlusion of the artery. During the course of the cuff's deflation, an oscillometric pulse (oscillometric waveform) generated on the arterial wall is detected by the pressure sensor and recorded for each heartbeat to take blood pressure readings. Over the deflation period, the oscilloscopic pulse amplitude increases to a maximum at one point and then diminishes sharply with further deflation until it reaches a point after which the amplitude remains nearly constant. The cuff's pressure at the maximum oscillometric pulse amplitude is referred to as the systolic (maximum) blood pressure while the cuff's pressure when the amplitude becomes unchanged is referred to as the diastolic (minimum) blood pressure.

3 Tonometry method
This method places a pressure sensor over an artery close to the skin, such as the radial artery, to detect blood pressure for each heartbeat. By applying mild pressure on the skin above the artery, the pressure sensor partially flattens the surface of the artery. The blood pressure value is determined from the pressure level at which balance is achieved between the force the pressure sensor applies on the artery and the force of the elastic artery to bounce back.

About Omron Healthcare
Committed to improving people's lives, Omron Healthcare provides clinically proven, innovative medical equipment for health monitoring and therapy. Our product portfolio includes blood pressure monitors, nebulizer, electronic thermometers, blood glucose monitors and activity counters as well as body composition monitors and professional medical devices. For many decades, Omron's devices have helped people to prevent, treat and manage lifestyle diseases both at home and in clinical practice in more than 100 countries in the world. Omron Healthcare Group is headquartered in Muko City, Kyoto Prefecture, Japan. Its President is Isao Ogino.

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