Signal and Power Integration in Medical Devices: Mixed Cabling Design Strategies

When developing modern medical devices, mixed cabling design is an absolutely critical challenge. These devices integrate power lines with high-speed or very low-amplitude signals within the same system.

High-precision equipment such as multiparameter monitors, diagnostic imaging devices, surgical robots, and life support systems require compact, reliable, and safe cabling solutions. In all cases, signal integrity and regulatory compliance must be ensured.

When power and data are integrated into a single harness, volume, weight, and costs decrease, although the risk of electromagnetic interference increases. Therefore, at Electrolomas we know that the design of hybrid harnesses, proper shielding, and a sound electromagnetic compatibility (EMC) strategy are fundamental from the earliest design phases.

Mixed Cabling Design: Hybrid Harnesses

Hybrid harnesses allow for the integration of power conductors, high-speed digital signals, and sensitive analog signals into a single interconnection solution. Their design must begin with a clear functional analysis of each line, considering voltage level, current, frequency, noise sensitivity, and clinical criticality.

Undoubtedly, internal segregation is among the key technical criteria. Although they share an outer sheath, power lines must be physically separated from sensitive signals using twisted pairs, internal sub-harnesses, or dielectric separators. This reduces capacitive and inductive coupling.

Material selection is also crucial. In medical settings, biocompatible insulation is prioritized. This insulation must be resistant to sterilization and possess good dielectric properties. Furthermore, properly sized conductors prevent overheating and voltage drops that could affect device operation.

A well-designed mixed cabling system addresses both electrical and mechanical criteria: bend radii, flex cycles, vibration, and ease of assembly directly influence long-term reliability.

Interference and EMC Mitigation

EMC is a critical regulatory and functional aspect of medical devices. Poorly controlled interference can lead to reading errors, false alarms, or even safety failures.

Among the most effective best practices is the use of individual and collective shielding. High-speed or low-amplitude signals must be shielded, with 360° terminations properly grounded to prevent ground loops.

The internal routing of the harness also plays a role: to reduce unwanted coupling, it is essential to maintain consistent distances, avoid prolonged parallel runs between power and signal cables, and cross lines at right angles whenever possible.

Proper grounding and reference management is another critical point. Designing a consistent grounding architecture, avoiding shared returns between power and signal, significantly improves the system’s EMC performance.

Finally, validating the results through simulations and early testing allows for the detection of problems before final certification, saving time and costs.

In short, a comprehensive approach to mixed cabling design is key to ensuring safety, performance, and regulatory compliance in medical devices. Choose Electrolomas; contact this leading supplier as soon as possible.