Advances in Wireless Medical Device Technology

Advances in medical device technology have improved efficiency and convenience for both patients and healthcare providers. Updating devices with wireless technology can improve patient compliance by making use of devices, such as for a cardiac stress test, more convenient.  Additionally, we see increased safety by removing a possible danger and point of failure (the wires). 

With increased use of wireless devices in the medical field comes the necessity to be assured that the information can be effectively transmitted from the collection device to the recording device.  These devices may be on the other side of a room or multiple rooms away in a central location.  Wireless InSite provides an effective platform to simulate point-of-care wireless device electromagnetic performance. 

As shown in Figure 1, we have modeled a point-of-care suite where cardiac stress-testing takes place.  The room is approximately 6 m by 5 m and contains a number of pieces of medical equipment.  A treadmill can be seen in the middle of the room.  The patient is modeled as a cylinder filled with a liquid commonly used as a human surrogate in EM testing.  The transmitter is represented by the green cube toward the patient's "front."  The receiving device is in the corner of the room on the far right side, with the receiver point represented by the red cube.  There are other objects in the room such as a supply cabinet, computer system, examination table, and physician's chair. 

The transmitting device is modeled as a half-wave dipole transmitting a 2.4 GHz sinusoid at 1 mW.  The energy is modeled using Wireless InSite's Full 3D model, which allowed up to 3 reflections, and 1 diffraction.  With approximately 9,000 faces in the scene, the project required about 13 minutes to run on a system with a 2.33 GHz processor and 4 GB of RAM.

Figure 2 shows the received power calculated across an XY grid 1.5 m above the room's floor. 

Figure 3 shows some selected propagation paths that reflect off of objects, walls, and the ceiling before reaching the device receiver point. The color of the ray path indicates the receive power level at the receiver.