The biological front-end SC2945 can be used in AED telemedicine equipment and is compatible with ADS1291

An AED, or Automated External Defibrillator, is a portable medical device capable of monitoring heart rate and effectively assisting patients in terminating ventricular fibrillation (VF) through rapid electrical shocks, thereby restoring normal heart rhythm. Ventricular fibrillation is the cause of approximately 80% of cardiac arrests, and defibrillation is the only effective method to prevent sudden cardiac death. For VF patients experiencing cardiac arrest, every minute of delay in defibrillation results in a 7-10% decrease in survival rates. Administering the correct aid within the first 5 minutes of cardiac arrest greatly increases the chances of successful resuscitation.

Remote-assisted medical care with AEDs comprises an AED data collection device, a remote server, and data terminals. The principle involves the AED data collection device collecting real-time audio information, real-time video information, location data, and AED data, and transmitting this data to a remote server. The remote server receives the information uploaded by the AED data collection device, stores it, and forwards it to data terminals.

The biological measurement front-end section within the collection device is of paramount importance. This article introduces a high-performance biological electrical measurement front-end analog chip, the SC2945, for use in remote-assisted medical care with AEDs.

The SC2945 biological electrical measurement front-end analog chip (compatible with ADS1291) integrates all the features required for portable, low-power electrocardiogram applications. It includes a built-in single-channel 24-bit Delta-Sigma (Δ-Σ) analog-to-digital converter (ADC), programmable gain amplifiers (PGA), internal references, and oscillators. Designed to ensure the accurate and stable capture of bioelectric signals while maintaining high precision and signal quality, the SC2945 boasts features such as ultra-low power consumption, high gain, and high sampling rates.

Key Features and Functions of the SC2945 Chip:

• Power consumption is as low as 420uW, and data rates from 125SPS to 16kSPS.
• Input reference noise: 8uVpp (150HzBW, G-6); input bias current 200pA.
• Common-mode rejection ratio (CMRR): 120 dB.
• Programmable gains: 1, 2, 3, 4, 6, 8, 12, 16, 24, 32, 64, 96.
• Oscillator initial accuracy: 0.5% (25°C), temperature drift ±1% (-40°C to 85°C).
• Single-supply voltage: Analog 2.7V to 3.6V; Digital 1.7V to 3.6V.
• Built-in right-leg drive amplifier, lead-off detection, and test signal; built-in pacing signal output and detection circuitry.
• Flexible transition between low power and standby modes.
• Compatible with SPI serial interface; operating temperature range: -40°C to 125°C.