The answer depends on the intended use.  If someone were to ask me, "What are the validated measures to obtain health information through WiFi" or any other communication means, the answer is still, "it depends on the intended use."  I'll provide below a general outline with some specific examples.  

Step 0: Determine if the system is a medical device vs medical device data system (MDDS) .  Probably the latter.  See FDA MDDS link

Step 1: Define the intended use.  What is the purpose of sending data through a text messaging system?  Examples:  Is it to real-time alarms?  If so, in what time frame do standards require the alarms to reach the clinician?    Lab data: Generally, no emergency, but if lab results indicate for example an critically low electrolyte level, this is a life-threatening event.    General patient status/information on which no clinical action depends.  Perhaps this is a system to allow a patient to access his EHR via text messaging, in which case there is likely no clinical issue if the messages are delayed for minutes or hours, but there is a user expectation of receipt of the data in a timely manner.  

Step 2:  Determine the requirements for supplying the data in a time that meets the intended use.  Example:  What latency and jitter are allowed?  What percentage of data loss is acceptable?  (If no loss is acceptable, then there is an implicit requirement to verify every packet is received).  Is coverage for transmission and reception require everywhere in the health care delivery organization?  What are the HIPAA requirements (is there electronic protected health information, ePHI) in the data that needs to be encrypted?  See HHS link.  What are the user and device authentication requirements to ensure only the proper people/devices have access to the data?  What is the user expectation for the reliability/accuracy/protection of the data?  Requirements generation should include a risk analysis.  You might consider ISO 14971 for guidance.  See ISO14971 link.

Step 3:  Design the product/system to meet the requirements.

Step 4:  Develop a test plan to test the system to the requirements

Step 5: Execute the test plan.  Assuming it passes, the system is validated.

Step 6: File regulatory paperwork.

http://www.fda.gov/MedicalDevices/ProductsandMedicalProcedures/GeneralHospitalDevicesandSupplies/MedicalDeviceDataSystems/default.htm

https://en.wikipedia.org/wiki/ISO_14971

http://www.hhs.gov/ocr/privacy/hipaa/understanding/srsummary.html

 Thank you for the explanation Dr.Baker.