Freescan® Frequently Asked Questions
1. Why do users have to input correct personal profiles, including gender, height, weight, and age?
Artery and blood property between individual varies, and personal profile may give a good guidance in the calculation formula. For example, female usually has a thinner artery wall than male
2. Many papers use optical sensor (photoplethysmography, or PPG) to measure pulse waveform. What is the difference from our force sensor?
PPG is best to measure volume change in capillaries, and it is commonly used to measure heart rate and oxygen saturation. It cannot measure the pressure change in artery directly, and PPT measured in capillaries is not stable. On the contrary, the sensor in Freescan® can measure detail pressure change in artery which is useful to determine artery characteristic.
3. Will the pressure applied on the skin affects the measurement result?
It is almost no effect. Freescan® senses the pressure waveform from radial artery wall by an adequate force applied. It does not occlude artery as much as a cuff-based BPM, and not measure the absolute pressure either. All the parameters are relative to time interval and the sensor is in good linear response, so as long as the signal is qualified, the reading will be consistent no matter if it is pressed harder or softer. In fact, Freescan® is more reliable, repeatable, and immunes to human operation in the same physical condition.
4. Will the position of the wrist affect the measurement result?
Yes, it may affect the measurement result. Users are asked to keep their lower arm horizontal (see user manual). It is best to have both hands steady by lying on support (such as a table).
5. What makes the measurement difference from a typical cuff-based BPM?
First the theory is different: cuff-based BPM measures the absolute number of applied pressure on the arm or wrist; on the contrary, measures time interval of signals and derives an “equivalent” blood pressure number. The time interval is a combinational consequence of pulse wave from the left ventricle along the aorta and arteries, so the result will be different from the single point pressure measurement by a cuff-based BPM.
6. How does stress level determine?
It is derived from the standard deviation of heart rate during the measurement. Higher heart rate variation indicates lower stress level, and lower heart rate variation indicates higher stress level. Please keep your breath normally and relax yourself during measurement.
7. Do I have to have APPS installed before using Freescan®?
No, Freescan® can be used as a standalone BPM. However, we strongly recommend users to install APPS on their smartphones. Bluetooth connectivity is built in Freescan® device, which synchronizes the data and setting with APPS on smartphones. The APPS will be able to manage your health history more comprehensively, so you can save much paper work and deliver to your doctor in more efficient way. In APPS you can even see your ECG and pulse signal for each measurement as a reference as well.
8. What are the benefits for users to upload the data to cloud?
The cloud does not only have a backup of your data, but also provides additional analysis, such as “artery age”. You are required to upload at least 10 data in 3 days so we can make more sophisticated statistic analysis. This function is implemented in cloud because it is based on statistic among a group of people. It is a relative index as a reference of your cardiovascular condition.
9. Can I handle the device to measure others’ blood pressure?
No, as explained in Technology, Freescan® senses both ECG and pulse signal; and users to be measured must handle the device on their own for ECG signal acquisition. The “start” button is also an ECG electrode.