Portable instrument and docking station with divided universal serial bus communication device

1. A docking station comprising:

a housing having a receptacle formed therein, the receptacle sized and configured to receive and support at least a portion of a portable medical instrument and including electrical contacts arranged to electrically connect with the portable medical instrument, wherein the portable medical instrument includes a first portion of a USB communication device adapted to communicate in a serial data communication format; and

a second portion of the USB communication device enclosed in the housing, the second portion comprising:

a serial to USB converter arranged in the housing and electrically connected to the electrical contacts, wherein the serial to USB converter is arranged and configured to convert between the serial data communication format and a USB data communication format to facilitate communication between the portable medical instrument and a host device; and

electronic circuitry that detects the electrical connection of the portable medical instrument with the electrical contacts and initiates the communication with the host device after detecting the electrical connection;

wherein the electronic circuitry detects the electrical connection of the portable medical instrument by detecting a logic transition that occurs on at least one of the electrical contacts; and

wherein the initiation of the communication causes enumeration of the portable medical instrument at the host device.

2. A docking station comprising:

a housing having a receptacle formed therein, the receptacle sized and configured to receive and support at least a portion of a portable medical instrument and including electrical contacts arranged to electrically connect with the portable medical instrument, wherein the portable medical instrument includes a first portion of a USB communication device adapted to communicate in a serial data communication format; and

a second portion of the USB communication device enclosed in the housing, the second portion comprising:

a serial to USB converter arranged in the housing and electrically connected to the electrical contacts, wherein the serial to USB converter is arranged and configured to convert between the serial data communication format and a USB data communication format to facilitate communication between the portable medical instrument and a host device; and

electronic circuitry that detects the electrical connection of the portable medical instrument with the electrical contacts and initiates the communication with the host device after detecting the electrical connection;

wherein the electronic circuitry detects the electrical connection of the portable medical instrument by detecting a logic transition that occurs on at least one of the electrical contacts; and

wherein the electronic circuitry further detects the electrical disconnection of the portable medical instrument from the electrical contacts by detecting an absence of a logic signal and terminates the communication with the host device after detecting the electrical disconnection.

3. The docking station of claim 2 , wherein the termination of the communication causes de-enumeration of the portable medical instrument at the host device.

4. The docking station of claim 1 , wherein the serial to USB converter is part of the electronic circuitry.

5. A portable medical instrument comprising:

instrument electronics adapted to generate data associated with a physiological characteristic of an individual;

a first portion of a USB communication device, the first portion comprising:

a processing device, the processing device programmed to generate messages, at least one of the messages including the data; and

a serial communication device that receives the messages from the processing device and transmits the messages to a docking station in a non-USB serial data communication format

an instrument including the electronics and the first portion of the USB communication device; and

a cradle having a receptacle sized to receive at least a portion of the cradle therein, and electrically connected to the instrument when the instrument is in the receptacle, wherein the cradle includes electrical conductors for passing electrical signals from the instrument to the docking station.

6. The portable medical instrument of claim 5 , wherein the first portion further includes electrical contacts, wherein the first portion determines that the portable instrument is connected to the docking station by detecting a logic level transition that occurs upon electrical connection of the portable instrument to the docking station.

7. The portable medical instrument of claim 5 , wherein the non-USB serial data communication format conforms to one of the following serial data communication standards: RS-232, RS-485, and RS-422.

8. The portable medical instrument of claim 5 , wherein the portable medical instrument is incapable of direct communication with a USB communication device of a host device through a USB cable.

9. The portable medical instrument of claim 5 , wherein the portable medical instrument is an infrared ear thermometer.

10. The portable medical instrument of claim 5 , wherein the cradle further comprises at least one pull-down resistor electrically coupled between at least two of the electrical conductors, wherein the instrument detects when it is inserted into the cradle by detecting a voltage change caused at least in part by the electrical coupling between the electrical conductors through the pull-down resistor.