One or more embodiments of this invention relate generally to a method and interface for cooling electronics that generate heat, especially electronics in ultrasound and biomedical systems.
As electronic devices are miniaturized, the amount of heat generated by the more densely populated electronics increases. As the amount of generated heat increases, the components within the device also operate at higher temperatures. These higher temperatures can degrade the performance of the devices. Moreover, the increased heat also emanates from the device. Accordingly, in some applications, for example, in medical ultrasound imaging probes that contact individuals during an exam, the increased heat not only can cause injury, but may exceeded acceptable regulatory levels. Accordingly, these devices have to be cooled.
In the medical imaging area, and particularly, in the ultrasound imaging area, heat is often a serious problem as a result of the intense processing that has to be performed at the scan head of the ultrasound probe. The dissipated heat from the scan head (e.g., from the miniaturized electronics in the scan head) needs to be transferred away from the scan head both to ensure the safety of the individual being scanned and to comply with certain regulatory guidelines to maximum heating conditions, which are especially critical when performing obstetrical scans. Additionally, increased heating of the scan head can affect the useful life of the ultrasound probe.
Current methods to dissipate the heat in devices with miniaturized electronics typically include heat sinks or heat exchangers that are complex, large and heavy. Thus, the reduced sized advantage gained from the miniaturized electronics is offset by the heat dissipation components that are needed. These current heat dissipation methods also add time and cost to manufacturing and maintenance, as well as result in a device that is often more cumbersome to use. For example, in ultrasound imaging systems (e.g., 3D ultrasound imaging systems), FR-4 (Flame Retardant 4) material is often used to manufacture the printed circuit boards within the probes of these systems. The processors and miniaturized components on these printed circuit boards generate heat that must be dissipated.
In order to dissipate the heat, these ultrasound imaging systems typically include several electronic circuit boards, for example, eight electronic circuit boards that are successively glued between metallic plates. The metallic plates are in connection with each other through one divergent plate on one side. The parallel metal plates function as cooling ribs for the electronic circuit boards and conduct to the divergent plate the heat dissipated by the electronics. The divergent plate is also connected to an aluminum body or housing. The assembly also may be surrounded in copper or aluminum tape. The aluminum housing includes machined channels to allow fluid flow therethrough. The channels are pneumatically connected to a connector end of a probe of the ultrasound system through tubing. The connector end of the probe includes a diaphragm pump and another aluminum body or liquid tank that is also in pneumatic connection with the tubing. Cooling liquid is circulated inside the tubing by the pump and through the two aluminum bodies (one at the transducer end of the probe and one at the connector end of the probe). This cooling system attempts to transfer heat away from the hand held transducer end to the connector end in order, for example, to meet mandated maximum temperature levels, as well as to improve the operation of the transducer. However, as a result of the different components needed in this cooling assembly, the overall device size and weight is increased, which affects the portability and potential applications for the ultrasound system. Also, the device is often time consuming to manufacture because the manufacturing steps have to be performed by hand. Additionally, the pump has a tendency to leak, which not only reduces the performance of the probe, but requires constant drying or maintenance.