Management application of medical power supply in various fields--Patient Monitoring
Patient monitoring
Such systems are all clinical systems. They are used to measure blood pressure, but can also be used in electrocardiogram (ECG) and pulse oximeter systems. This type of power management usually uses line power, so as long as heat dissipation can be handled well, energy efficiency is not a big issue. What is really important is reliability, galvanic isolation for safety purposes, and low noise. To increase reliability, backup batteries are sometimes provided. When patients are transferred to different hospitals, spare batteries help provide uninterrupted vital signs monitoring.
Isolation needs to comply with the most stringent medical safety standards, namely IEC 60601-1. Digital isolators using iCouplers technology are replacing optocouplers without affecting isolation integrity. The advantage of this trend is to avoid the aging effect of optocouplers to obtain long-term stability, while providing different semiconductor functions in a single package, such as USB, I2C, and power management switching regulators. These devices provide reinforced insulation and can withstand the 10kV surge specified in the IEC 60747-5-5 standard. iCoupler products use chip-scale transformers, which have very robust common-mode transient immunity compared with optocouplers and capacitor-based digital isolators.
Figure 4: Concept of inductive digital coupling across the isolation barrier.