Abstract: An ambulatory recording system for medical and especially diagnostic purposes is described having synchronized communication between two processors. The recorder features two processors which are of differing architectures—the first processor being a real time processor which handles the sampling function, the second processor being a non real time processor which handles the operating system function. The invention further includes a protocol for communication between the two processors which permits the two processors to have synchronized and reliable communication.

Abstract: An ambulatory data recorder with enhanced infrared data transfer. In particular, the device features an infrared transmitter port having a multi-plane lens. The port, lens and recorder enclosure work together to permit a reliable infrared data link to be established between the recorder and a line voltage device even while the recorder is in a variety of positions. That is, the infrared data link may be established when the device is worn, of when the device is placed on a table in a variety of positions.

Abstract: An ambulatory recorder having real time non-real time processors is described. The real time processor handles sampling functions while the non real time processor handles other functions, such as high processing operations associated with multitasking, graphical user interface, floating point calculation, Infra Red communication and long term memory storage. The second processor is primarily provided to operate a Windows CE operating system as well as one or more embedded applications. Through this design, electrical power provided by a battery is only consumed by those components essential to device operation at any particular time.

Abstract: An ambulatory data recorder having a slidable patient activity period switch. The slidable patient activity period switch permits the patient to slide the switch from a first position to a second position upon the start of a pre-defined activity, e.g. eating. Upon completion of the pre-defined activity, the switch is slide from the second position back to the first position. While in either the first or second position the switch position corresponds to a marking on the recorder enclosure such that the patient can readily understand which activity the switch is indicating. The slidable patient activity period switch is further configured to have minimal power consumption. In one embodiment the switch is provided through a standard keyboard interrupt service routine.

Abstract: An ambulatory device having a case with an integral splash cover about the area of the catheter input ports is described. Moreover, the ports are angled such that when the device is carried in its intended manner by a patient, the ports are angled downwards. Through the case design, in combination with the angle of the ports, the device is relatively more resistant to splash-related problems as compared to prior devices.

Abstract: An ambulatory recording system, for medical and especially diagnostic purposes, is described having a communication watchdog between two processors. The two processors may be of differing types. For example, the first processor may be real time processor ("RTP") which handles the sampling function, while the second processor may be a non real time processor ("NRTP") which handles the operating system function. This dual processor design permits relatively low power consumption for data recording (which is handled by the relatively lower power consuming RTP), while also providing a graphical user interface for user simple user operation (which is handled by the relatively higher power consuming NRTP). A communication watchdog between the two processors is provided to reset the device upon the detection of a processor failure or communication failure between the two processors.