With advances in medicine and healthcare, the average life expectancy of humans continues to increase. The size and proportion of the elderly population is growing in almost every country in the world, and the total population aged 65 or over is expected to double to 1.5 billion by 2050. At the same time, home care or nursing facilities must scale up to support this growth.

According to the Centers for Disease Control and Prevention, nearly 25 percent of older adults fall each year, and falls are the leading cause of trauma-related hospitalizations among older Americans. Knowing when a fall or other health-related event occurs and being able to respond quickly helps ensure that individuals receive the care they need.

Technology Today – Home Health

Medical sensors and innovations in connectivity are helping seniors live normal lives at home and ensuring that if anything happens, help is nearby. These medical sensors are often based on accelerometers to detect motion signatures such as falls and can automatically call family or caregivers for help.

Elderly people must wear these battery-powered sensors around their necks or wrists; their placement on the body helps the sensors identify macroscopic motions such as falls and use connected nodes to contact family members or caregivers. Other sensors, such as electrocardiograms or pulse oximeters, can also provide a continuous view of health parameters, such as vital signs or sleep quality.

These medical sensors have their own challenges, as shown in Figure 1. To be effective, consumers must remember to wear them and charge them, which may not always be comfortable or feasible. Some models require a button to be pressed in the event of a health event, but this is useless if the person is incapacitated. Finally, the sensors need to be very accurate in order to distinguish between falls and everyday activities. Today’s sensors are prone to false detections when a person is sitting down quickly or clapping their hands. Sensor types like those used in optical cameras also present privacy concerns when placed in the home.

Figure 1: Technology can help enable home health by addressing issues such as detecting occupancy or movement, falls, and vital signs of long-term health trends or sleep quality

Millimeter-Wave Radar: Non-Contact, Privacy-Focused Sensing

60 GHz millimeter wave (mmWave) radar is an alternative sensing technology for detecting and tracking health and behavior in the home. Radar can help solve a variety of sensing challenges, including determining whether a room is occupied (and how many), identifying motion signatures to identify falls, and measuring a person’s vital signs to assess sleep quality. By its very nature as an RF-based sensor, mmWave radar senses without touching the body, and since the sensor does not provide any visually identifiable information, it can be installed in sensitive areas such as bedrooms or bathrooms . Combining these capabilities at the application level can help home monitoring systems reassure loved ones and caregivers that a person is safe and healthy.

The IWR6843AOP uses an on-chip antenna and is onboard with a microcontroller and digital signal processor for handling range, speed and target angle processing. The range and angle information can be used to generate a “point cloud” that, when fed into a history tracker, can determine not only whether a room is occupied, but also where someone is in that room. This point cloud and tracker information can be used to determine whether a person is moving or sedentary, or if they are exhibiting normal behavior, such as walking to the kitchen in the morning.

Using the example of a radar point cloud indicating a fall, Figure 2 shows the point cloud as a green dot, with a red trajectory assigned to the cluster. The graph on the right shows measurements of a person’s instantaneous and average height, which the algorithm can use to detect if a person has fallen.

Figure 2: Example of a radar point cloud from a fallen person

Velocity information can measure the motion characteristics of objects in the room. Through tailor-made algorithms or artificial intelligence, these motion signatures can identify behaviors such as unsteady gait, falls or near-falls. Another use is at the bedside to measure movement during sleep and determine if sleep patterns are changing. As shown in Figure 3, motion signatures can even measure a person’s heart rate and breathing rate while sitting or lying down.

Figure 3: Heart rate and respiratory rate measured using the IWR6843AOP sensor mounted at chest height of 1.2 m and 2.5 m from a seated person.

In Figure 3, the upper graph is compared with the processed output of the IWR6843AOP (green line) using a chest commercial heart rate monitor (black line). The heart rate error is less than 5 bpm (relative to the ground truth of the chest-mounted sensor), demonstrating good measurement accuracy without the need for the sensor to touch the body.

in conclusion

mmWave radar is an evolving technology well suited for new and innovative features in home monitoring and medical. Check out some of the resources linked in this article and listed below to learn more about mmWave radar sensors, including evaluation modules, demonstration software, or solutions from one of our third-party partners.

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