Bluetooth vs. BLE in Medical Devices: Understanding the key differences

Both Classic Bluetooth and BLE use the 2.4 GHz ISM (Industrial, Scientific, and Medical) band, a globally available frequency range used for wireless communication. However, their approaches to data transmission, power consumption, and application are different.

Before diving into comparisons, one key concept to understand for both Classic and BLE is data rate. Data rate refers to the speed at which data is transmitted between devices, typically measured in kilobits per second (Kbps) or megabits per second (Mbps). Higher data rates allow for faster and more continuous transmission, while lower data rates are more energy-efficient and suitable for devices that only need to send small amounts of data periodically.

• Designed for continuous, high-bandwidth data transmission
• Typically used in audio streaming, file transfers, and hands-free calling
• Requires more power, making it unsuitable for battery-powered medical devices

• Optimized for minimal power consumption
• Sends small packets of data at intervals rather than continuously
• Ideal for sensors, wearables, and implantable medical devices

One of our most insightful projects at HTD involved developing an app for a wristband-style device designed to help patients manage hand tremors, such as those caused by Parkinson’s disease. This project demonstrated why Bluetooth Low Energy is the go-to choice for medical devices:

• Power efficiency: The wristband needed to function for extended periods without frequent recharging.
• Easy to understand and implement: The entire communication protocol can be described as a set of four operations: scan (device discovery), read, write, and notification (unattended reads). This simplicity reduces the likelihood of software failures.
• Simple and reliable communication: The device only needed to send periodic movement data, making high-bandwidth transmission unnecessary. The total transmission rate is in order of a few hundred bytes per minute.
• Small form factor: BLE allowed the device to remain lightweight and comfortable for the wearer.

This comes with a caveat—transmitting large data payloads can take a lot of time. For example, updating the device firmware through BLE will take several minutes. However, this is not a common operation, so the benefits are still worth this small inconvenience.

Medical devices often have strict requirements regarding battery life, data transmission, and usability. Here’s how Bluetooth and Bluetooth Low Energy (BLE) compare in those areas:

The rise of BLE in healthcare isn’t just a passing trend—it’s a direct response to the needs of modern medical devices. Take our tremor control wristband project as an example. The device needed to:

• Communicate efficiently with a smartphone app
• Operate for long periods on a small battery
• Remain comfortable for the patient
• Transmit movement data reliably without draining power

For these reasons, BLE was the clear choice. It allowed us to build a solution that met all the necessary technical and usability requirements.

However, not all medical devices rely on BLE. Larger devices, such as portable ultrasound machines, benefit from Classic Bluetooth due to their need for continuous, high-data-rate transmission and their ability to support a larger power source.

While BLE is the preferred technology for medical devices, it does come with challenges. Here are some we’ve encountered—and how we solved them:

• Different phone manufacturers handle background processes differently, leading to inconsistent performance.
• Our solution: Standardize on specific phone models during clinical trials to ensure stability.

• Android fragmentation makes BLE communication inconsistent across different phone brands.
• Our solution: Initially focus on supporting specific phone models for medical trials, then expand support for commercial releases.

• BLE devices need to handle potential connection drops gracefully.
• Our best practices include:
  • Simplified pairing processes
  • Automatic reconnection
  • Clear feedback on connection status
  • Handling interference effectively

At HTD, our experience developing applications for medical devices has shown us that BLE is often the right choice for healthcare applications. While Classic Bluetooth has its place in high-bandwidth use cases, most medical devices prioritize power efficiency, intermittent data transmission, and small device size—areas where BLE excels.

Whether it’s a tremor control wristband, a heart rate monitor, or an implantable sensor, BLE allows medical devices to function efficiently without frequent charging. As healthcare technology continues to evolve, BLE will remain a foundational technology for innovation in wireless medical devices.