Pulse Wave Velocity measurement

Pulse Wave Velocity (PWV) is considered as the gold standard in the assessment of arterial stiffness, can be conducted to evaluate efficacy and effectiveness of anti-aging and nitric oxide boosting interventions (such as oral hygiene, mouth taping, diet with dark leafy green vegetables, physical exercise, sauna, red light, fasting and sunbathing), yet the accuracy of portable devices for home use might vary.

Which ones are the best?