Contactless (BCG) technology (Ballistocardiography) or cardiac shock mapping is of great interest in the field of biomedical measurements and health monitoring. This technique is used to monitor the human heart's activity, in particular the mechanical vibrations of the heart. It works on the principle of recording and analysing the tiny vibrations generated by the beating heart and blood flow in the human body, by recording and analysing these vibrations without direct contact with the skin.

2.1. Sensors: Contactless BCG technology uses highly sensitive sensors such as piezoelectric sensors. These sensors are able to detect the vibrations caused by the heartbeat.

2.2. Data Acquisition: The vibration data captured by the sensors is transmitted to a background computing device, such as a computer or mobile device, for further analysis.

2.3. Data analysis: By analysing the vibration data, useful information about the cardio activity can be extracted. This includes information such as heart rate, heartbeat intensity, systole and diastole of the heart.

2.4. Application areas: Contactless BCG technology can be used in a variety of medical and physiological monitoring applications, including sleep studies, heart health monitoring, health care and more. It is non-intrusive, requires no direct contact with the skin, and is non-invasive, which gives it an advantage over traditional biomedical measurement methods in some cases.

- BCG (ballistocardiography) is a non-invasive, non-contact, convenient means of monitoring cardiovascular function.

- LANGZHI uses PVDF sensors to collect BCG signals when the human body is resting in bed, and determines the time interval between heartbeats by the similarity of adjacent heartbeat signals, generating the current heart rate or respiration value.

- The calculation of heart rate and respiration using BCG technology is non-contact, without the need to wear any sensors, to achieve senseless monitoring. This ensures that the collected data reaches medical grade accuracy without affecting the user's normal sleeping habits and sense of use.

- When the heart rate or respiratory rate is abnormal: the main page of the APP displays the alert status in real time, and at the same time, it records the historical data and sends an additional short message to remind the user.

- Non-contact, no need to wear it.

- Non-invasive, avoid skin allergies.

- Real-time tracking to keep track of the heart's (or cardio) status.

- Suitable for people of all ages and health states.

- Suitable for sleep tracking and helps to understand health problems related to sleep quality.

- Non-restrictive, this technology requires no special preparation or operational requirements.