Electronic devices such as camera systems used in or with minimally invasive medical instruments generally have stringent performance requirements. In particular, such devices must be small enough, e.g., less than about 10 mm in diameter, to be inserted through a cannula or other guide and must be long enough to reach a work site within a patient in order to perform the required function. For example, a camera system for a minimally invasive medical instrument must be able to provide a surgeon or other clinical personnel with moving images, typically stereoscopic views, of sufficient clarity to enable precision procedures. The high image quality and reasonable frame rates generally require high-frequency data transmissions for digital transmission (e.g., from CMOS cameras) along the relatively long length of the instrument. The long signal path and metal employed in a shaft or other part of the medical instrument can unintentionally provide an effective antenna that could generate electromagnetic interference (EMI) particularly from high frequency data signals. Careful shielding of signals, particularly data signals, may thus be required.
Another issue for electronic devices in minimally invasive systems is generation and dissipation of heat. For a typical minimally invasive medical system, the heat generated from operation of a distal electronic device must be removed from a work site within a patient. Otherwise, heat buildup within the patient may interfere with operation of the device or worse injure the patient. Active cooling systems, e.g., that rely on electro-mechanical cooling techniques such as air or water flow or thermoelectric cooling devices, may consume premium space within the instrument and increase the complexity of the instrument. To provide a more compact device, passive cooling that conducts heat from the distal tip of the instrument may be used, but a heat conduction path from the distal tip of the instrument may be narrow and long, restricting heat flow and increasing the operating temperature of the electronic device. A mounting for an electronic device such as a camera system that is passively cooled should thus provide a thermal contact with low resistance to heat flow regardless of the length or narrowness of the heat path.
Yet another issue for connecting an electronic device at the distal end of a minimally invasive medical instrument is the ability of the connection to withstand forces that occur when the instrument moves or flexes. For example, a camera system at the distal end of a probe may need to be positioned and pointed for viewing of a work site from a user selected viewing point. A connector for such an electronic device must thus be able not only to withstand the forces that movement of the electronic device causes but also maintain electrical connections, EMI shielding, and a low-resistance thermal connection during such movement.