Various IH Cooking Heater Tests

Effectiveness of the MG Vest in Preventing PM Malfunctions Caused by IH Cooking Heaters (Induction Cooktops)

Objective

This experiment evaluated whether the MG Vest could prevent pacemaker (PM) malfunctions caused by electromagnetic waves emitted from IH cooking heaters.

Method

A human phantom was equipped with a PM. To simulate the situation of leaning over a pot—where electromagnetic leakage is greatest—the IH cooking heater was tilted at a 45° angle, and the human phantom was positioned directly in front of it as shown in Figure 1. The shortest distance from the center arc of the PM leads to the outer edge of the IH heater’s top plate was measured to determine how close the IH device can approach before malfunction occurs. (Criteria for determining malfunction)

A tabletop IH cooking heater manufactured in 1994 was used. Its maximum power consumption was 1350W, and the power setting was set to high.

Figure 1: Test Configuration

As a safety mechanism, the IH heater only operates if a ferromagnetic pot is placed centered over it. We tested both with the pot centered and with the pot shifted to the edge where operation was still possible but leakage was greater, as confirmed via oscilloscope measurements. The shifted placement showed stronger electromagnetic leakage, so it was used in testing. Larger pots caused greater output, so a 22 cm diameter pot (matching the top plate) was used. A probe was placed near the PM in the phantom and connected to an oscilloscope to measure the frequency of leaked electromagnetic waves.

Results

Of the 20 PM models tested, 8 exhibited inappropriate operation. The results are shown in Table 1.

(Unit: cm)

(- indicates no inappropriate operation occurred at the minimum measurable distance of 10 cm.)

Discussion

The leads were wound centrally in a double loop and used unipolar leads, with sensitivity set to maximum and refractory period to minimum. Thus, the phantom test conditions were more prone to malfunction than actual human conditions. The heater was tilted at 45°, the pot was offset to the limit, and heating power was set to high—all of which represent the most hazardous conditions for PMs. While such a scenario is rare in reality, it is considered suitable for testing the effectiveness of protective garments.

Conclusion

The MG Vest demonstrated the ability to shield electromagnetic waves emitted by IH cooking heaters and prevent inappropriate operation of pacemakers.

A clinical trial based on this study was conducted, and the findings were presented on September 3, 2005, at the 14th Kinki Pacemaker Clinical Forum. Presentation Details