Brushless, direct current (BLDC) motors are one of the options for motion control solutions in medical device development. BLDC motors typically offer higher power, higher efficiency, and lower wear than comparably sized motors of other types. The main challenge in incorporating these motors is the complexity in the drive electronics and control strategy. As an […]
A common challenge when designing medical devices that make optical measurements is ensuring the optical system state remains correlated with sensor measurements in order to maximize medical device optical signals. The sort of device I’m speaking of achieves its measurement by illuminating something and collecting the scattered or transmitted light. For this conversation, that “something” […]
Reference designs for medical device development are a great way to ramp up a project faster and more cost effectively. At work, we’ve adopted a strategy of developing our own reference designs of subsystems that we believe will be useful in future projects. A reference design is an implementation of a technology – such as […]
When I say temperature sensors, you’ll likely think thermocouples. But today I’d like to discuss NTC thermistors. Medical devices regularly need to measure temperature. Often engineers overlook or under-estimate the inherent challenges. Whether designing in thermal measurement and control capability or just temporarily instrumenting up a test rig, it’s worth thinking about how the device […]
Using Matched Filters Anyone who has taken a signals and communications course has likely heard of matched filters. Intuitively these filters use knowledge of the form of a transmitted signal to pull it out of the noise. Matched filter theory or related concepts are commonly used in RF communication but I often apply it to […]
CPU modules are off-the-shelf PCBs that combine a powerful microcomputer, support circuits and a number of key peripherals with their electrical connectivity provided by board-to-board connectors. This makes them perfectly suited to be incorporated onto a custom PCB in a medical device or IVD.
Open Source Software (OSS) is software with a copyright license that includes the right to view and alter the source code and to distribute derivative works. Usually, OSS is available free of charge and therefore offers the possibility to get a significant head start on your medical device development.
In many medical devices, especially those that are microprocessor controlled, it is common for programmable subsystems to communicate via asynchronous serial protocols. Such subsystems include things like programmable power supplies, syringe pumps, temperature controllers, motor controllers and smart linear actuators. I’m often surprised by how many of these devices have poorly thought-out protocols that make it […]
Lithium rechargeable batteries achieve some of the highest energy densities available today. Not surprisingly, medtech companies are keen to use lithium batteries in medical devices and benefit from reduced weight or increased battery life. There are a number of safety implications to choosing these batteries as well as practical business implications.
I find myself regularly designing motion control systems as part of the internal mechanisms of Medical Devices. There are predominately two types of motors that I use nowadays: DC motors and stepper motors. I find that knowing a little bit about how each of these motors operate and how they are typically used makes it […]
Prior to constructing ultrasound images out of raw radio-frequency (RF) data, the transducer pulse frequency must be removed from the data to prevent ripple artifacts in the image. There are a number of methods of demodulation in ultrasound although two ultrasound signal processing techniques are used predominately nowadays.
Last week I shared ideas, tips and suggestions that I believe increase the chances of being successful when designing printed circuit boards. Here’s a few more that come to mind.