It is amazing how advancements in technology have revolutionized medicine in terms of analysis and imaging tools or technologies for minimally invasive surgery. And the trend goes on: more and more robots are used for surgeries, resolution of pictures is getting higher, and the RF surgical devices can carefully control the energy for a perfect cut or seal process.
This customer was working on the third generation of its RF surgical device and wanted to not only increase power to 800W but also add additional features for the surgeon, while maintaining the existing size of the equipment. The legacy power solution was only able to deliver 700W at maximum and the built-in fan would start when delivering more than 50W power.
As audible noise matters in
medical applications, getting rid of that noise source was another important point on the wish list for the redesign, which turned out to be a major challenge.
It was only until the customer talked to RECOM, which offers one of the world’s smallest AC/DC power supplies with up to 1000W power (conduction cooled), that thy realized there was a successful path to market. The RECOM solution took significantly less space than the previous
power solution. This freed up space for the additional circuitry needed for enhanced and new features.
This power supply not only generated less heat losses due to its very high efficiency, but also offered conduction cooling to the chassis of the medical device. Heat management became much easier, and no noisy fan was needed so the device works silently, a very important factor during surgeries.
With all these benefits, the customer was able to gain additional space in the existing housing for all the advanced and new features they wanted to add to the device during the redesign.
Most of the power is used by the RF generator and other voltages needed in the system like 24V, 12V, and 5V are generated from this 48V bus by small DC/DC converters from RECOM. A big advantage of this distributed power architecture was that currents on the bus are now low. Only thin wires or small traces on PCBs and smaller connectors are needed. For example, powering a 5V 6A load from the 48V bus with a local DC/DC converter reduced the current on the 48V bus down to less than 700mA. An additional advantage is that these point-of-load converters can be deployed across the system close to the load. This not only allows optimal usage of available space but also helps to spread heat across the system avoiding hot spots.
The main power supply used in this application has medical approvals and a completed risk assessment document, which helped reduce the cost for the final medical approval of the device. Moreover, the switching regulators used within the device power only the internal circuitry without direct patient or operator contact: so, compact industrial grade parts could be used, thus reducing the overall costs.
Feedback from the market was that besides the new features, the fanless, and therefore noiseless, operation was considered as one of the biggest, competitive advantages.
