A method of obtaining and installing, into a memory of a wearable computer device, analysis results for a biological sample of a user, the method comprising: providing a test cartridge for performing tests on said biological sample, the test cartridge being provided with a computer-readable test cartridge identifier; using a computer device to: read (302, 401) said computer-readable identifier from the test cartridge; receive user account information, and communicate with a server or servers via a data communication network to set-up a user account, associated with said test cartridge identifier, at said server(s); mechanically connecting the test cartridge to a test control system; at the test control system, sending (305, 406) the test cartridge identifier to said server(s) via said communication network so that the server(s) can associate a test being run with said user account; operating (306, 408) the test control system to cause the test cartridge to perform said tests on the biological sample in order to obtain test results; sending (308, 416) the test results from the test control system to said server(s) via said communication network; at the server(s), processing (309, 417) the test results to generate analysis results; using the user account information to send an activation code to the user, wherein the activation code allows a personal computing device of the user to retrieve the analysis results; sending the analysis results to the wearable device and installing them into said memory of the wearable computer device, the analysis results comprising information which defines a product recommendation for benefitting the health of the user, or from which such a product recommendation can be derived, for each of a multiplicity of product codes, the method further comprising installing a database containing said product codes into a memory of the wearable device either before, during or upon or following completion of said test. providing a test cartridge for performing tests on said biological sample, the test cartridge being provided with a computer-readable test cartridge identifier; using a computer device to: read (302, 401) said computer-readable identifier from the test cartridge; receive user account information, and communicate with a server or servers via a data communication network to set-up a user account, associated with said test cartridge identifier, at said server(s); read (302, 401) said computer-readable identifier from the test cartridge; receive user account information, and communicate with a server or servers via a data communication network to set-up a user account, associated with said test cartridge identifier, at said server(s); mechanically connecting the test cartridge to a test control system; at the test control system, sending (305, 406) the test cartridge identifier to said server(s) via said communication network so that the server(s) can associate a test being run with said user account; operating (306, 408) the test control system to cause the test cartridge to perform said tests on the biological sample in order to obtain test results; sending (308, 416) the test results from the test control system to said server(s) via said communication network; at the server(s), processing (309, 417) the test results to generate analysis results; using the user account information to send an activation code to the user, wherein the activation code allows a personal computing device of the user to retrieve the analysis results; sending the analysis results to the wearable device and installing them into said memory of the wearable computer device, the analysis results comprising information which defines a product recommendation for benefitting the health of the user, or from which such a product recommendation can be derived, for each of a multiplicity of product codes, the method further comprising installing a database containing said product codes into a memory of the wearable device either before, during or upon or following completion of said test.