Cause of Device-Related Incident
Device factors; External factors

Clinical Specialty or Hospital Department
Anesthesia; CCU / ICU / NICU; Clinical/Biomedical Engineering; Gift Shop; Nursery; Nursing; OR / Surgery; Pediatrics; Pulmonary / Respiratory Therapy

Device Factors
Device interaction

Document Type
User Experience Network (UEN) reports

External Factors
Electromagnetic or radio-frequency interference (EMI and RFI)

Mechanism of Injury or Death
Failure to deliver therapy; Monitoring failure

Tampering and/or Sabotage
*Not stated

User Errors
*Not stated

UMDNS
Nurse Call Systems [15-614]; Oximeters, Pulse [17-148]; Oximeters, Pulse, Telemetric [17-667]

Furby Toys Are Not Likely to Interfere with Hospital Equipment



User Experience Network [Health Devices Jan-Feb 1999;28(1-2):81-2]

Hospital

Occasionally, pediatric patients and younger visitors to the hospital bring a toy called a Furby with them into the facility. Because these toys are mechanized and can transmit infrared signals, some of our clinical staff have expressed concern that the toy may interfere with medical equipment. Is this a valid concern?

ECRI

We believe that interference with medical equipment by a Furby toy is highly unlikely. Thus, although the possibility of interference cannot be completely ruled out, we believe that banning these toys from the hospital is unnecessary.

The Furby is a small, microprocessor-controlled stuffed animal manufactured by Tiger Electronics Ltd. (a division of Hasbro) for children aged six and older. The toy can move its eyes, mouth, and ears using a small electric motor powered by four AA batteries. These batteries also power various sensors and two small microprocessors that control the Furby. The Furby has a number of automated capabilities—for example, it moves and talks in response to sounds in its vicinity, it imitates certain sounds, and it can simulate conversation with other Furbies. To perform this last function, Furbies exchange short infrared signals.

Some hospitals have expressed concern that the Furby's motor, microprocessors, or infrared transmitter may cause interference with medical devices. However, we believe there is no significant risk of this happening. Since November 1998, when the Furby was first sold, ECRI has received no reports of medical device interference or malfunction attributed to the toy. In addition, we have researched certain aspects of the Furby's operation—this included performing some tests—and believe the toy is unlikely to cause problems in hospitals. Unfortunately, the concerns about the Furby have created excessive media attention, and some hospitals have reacted by needlessly banning the toy.

The two specific areas that have provoked concern are the production of electromagnetic noise by the Furby's motor and microprocessors and the toy's use of infrared signals. Our investigation of these areas is discussed below.

Electromagnetic Noise

We investigated the Furby's electromagnetic noise production using a spectrum analyzer and found that the toy does produce electromagnetic noise over the frequency range of the spectrum analyzer (up to 500 MHz). However, the noise appears to be of low amplitude, and it quickly diminishes when the Furby is moved away from the analyzer. We also placed the toy directly alongside the transmitters and receivers of two different telemetry systems, with each system transmitting and displaying a simulated ECG signal. We did not detect any distortion in the ECG signals.

To cause a medical device to malfunction, the electromagnetic fields generated by the toy would need to be strong enough to interrupt or distort electronic signals in other electronic devices, or to generate additional signals detected by those devices. Although the Furby produces a small amount of electromagnetic noise, we believe that this noise is of insufficient amplitude to interfere significantly with medical devices, even those in the toy's immediate vicinity.

Infrared Signals

Within a hospital, three types of medical devices that use infrared signals are commonly encountered: certain operating room (OR) equipment, nurse call systems, and pulse oximeters.

OR equipment. It is highly unlikely that a Furby would be found in an OR. Therefore, we did not investigate the toy's effects on the infrared-based functions of equipment used in this setting.

Nurse call systems. Although nurse call systems use infrared signals, those signals are very different from the ones produced by a Furby. A Furby generates an infrared pulse by switching its infrared emitter on and off only once. On the other hand, during each pulse produced by a nurse call system, the infrared emitter is turned on and off many times, at a very high frequency (in the kilohertz range). The infrared receptors of nurse call systems are designed to recognize these high-frequency pulses and would be unlikely to respond to the type of signal produced by a Furby.

Pulse oximeters. We tested the effect of the Furby's infrared signal on pulse oximeters by placing the toy's infrared transmitter directly alongside the reusable probe of a pulse oximeter being used on a human subject. (We employed a reusable probe because it is more likely to be susceptible to infrared interference.) The probe clamps to the top and bottom of a subject's finger, with its light detector on the underside. We positioned the Furby above and to the side of the subject's finger so the infrared signal could pass through the finger and strike the light detector.

We performed this test twice, each time using a different pulse oximeter. We did not detect any changes in the pulse oximeters' SpO2 values or pulse measurements while the toy emitted infrared signals. This was most likely because the toy's pulses were too infrequent to affect the pulse oximeter, which generally averages its measurements over several seconds.

Conclusions

Some hospitals may believe that it is best to ban the Furby to eliminate any risk of interference with medical equipment. In our opinion, such a ban is unnecessary. The Furby, like any other toy, may have a calming effect on a child being treated in the hospital. Given that a Furby's electromagnetic output is small and that its infrared emissions involve a simple pulsing scheme, ECRI considers it safe to allow Furby toys into the hospital, even in the immediate vicinity of medical equipment. In the unlikely event that a Furby does produce interference, we urge any healthcare institution experiencing such a problem to contact ECRI.

UMDNS Terms

  • Nurse Call Systems [15-614]
  • Oximeters, Pulse [17-148]
  • Oximeters, Pulse, Telemetric [17-667]

Cause of Device-Related Incident

Device factor: Device interaction

External factor: Electromagnetic or radio-frequency interference (EMI and RFI)

Mechanism of Injury or Death

Failure to deliver therapy; Monitoring failure


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