So how did my talk go?
My talk went reasonably smooth, overall I was happy with what I could put together in limited time. According to the polls and some in person conversations people seemed to like the fact that I attempted to break it down with a technical deep dive, especially taking time to go deeper on on-the-wire protocols and standards.

The talk was recorded by Robert Wood Johnson foundation and I’ll post a link around when they make it available online.

OSCON Healthcare Track
I attended most of the talks at OSCON HealthCare track. This was the first Healthcare track at the conference, in my opinion it turned out splendid! Andy Oram has a good summary of the first, second & third day, and Fred Totter has links to interviews of some of the presenters. Over the three days of Healthcare track I learnt a lot about various NHIN and VistA projects.

Sessions
In addition, I attended a few session and a couple of tutorials. I’ll summarize some of them below with key take-away or interesting links :

• Cloud computing  – “Situation Normal, Everything Must change”: If nothing else I would highly recommend watching this key-note, no new content but the Simon Wardley is very effective in communicating his point about Cloud computing and managing technology in general.
• Asynchronous Programming – I learnt a lot about nginx web-server and the principles behind node.js. Ilya’s talk was specific to Ruby but learnt a lot about the perf gain PostRank has gotten owing to Asychcrony. He was gracious to have lunch with me and one of interesting things he mention was use of AMQP. AMQP is near real-time (low latency, high throughput) general purpose message standard used by most of the guys on Wall-street! An open source implementation of the same is RabbitMQ.
• Another Go at Language Design: Since I’m a compiler wonk and systems’ programmer, it was great to see Rob Pike’s presentation on Go language and specially see the fast Go compilers, most optimizations are owing to managing the dependencies for linking.
• jQuery – The presentation on jQuery was very detailed even for a novice. I particularly liked the show-casing of selectors to write succinct iavascript code.
• Graph Database – Neo4j : At fore front in the NoSQL camp Neo4j offers up to 1000x performance gain over relational database for implementing applications like a social network. Key different from RDBMS is that the Graph itself is the main index!
• Android: I learnt a quite a bit about Google Android and their development methodology. Android developers in general focus a lot on remove perceivable slowness from the application (called “Jank” in Google lingo).Anything which takes more than 200ms to process is considered bad. A good rule of thumb to prevent “Jank” is to never stall the event loop.  To spur further Android excitement Google gave away the soon to be de-commissioned Nexus one devices in one of their workshops. 
• Open stack:Open source system for creating Amazon EC2-like clouds. In fact this project is open sourcing of the RackSpace cloud system.
• An interesting project to cross-compile Android projects to iPhone.

Birds of feather session on Healthcare Standards
I participated in the BOF on Healthcare Standards.

The conversation started by highlighting the classic problem of how people who have been in the industry want semantic interoperability  and how the new entrants in the area want simple systems. I contribute to this conversation by pointing out that if standards get developed with industrial strength open implementations they are more tend to be more sane (read NHIN-D).

The conversation then drifted towards terminologies. Everyone in the room was outraged with CPT and AMA’s greed J. David Riley (head of NHIN project) added to the conversation saying that ICD-10 procedures are designed to replace CPT. I contributed to the conversation detailing how it’s difficult to develop a coherent system with all the different vocabularies with different licensing requirement and incomplete  mappings to each other. David was then gracious to detail a project done in the federal government where they attempted to come up with a common terminology service by inventing something akin to OIDs for each terminology. He is hoping that he can open source those terminologies sometime soon. Brian Bhelendorf then added to the conversation asking how can we enable or create open source terminologies. I was suggested that may be can do something like RxNorm to create a uniform mapping system which the terminology licensors can adopt. There was more discussion on this topic, no one felt that UMLS was adequate.

PS: I’ll update the this post with more links and thought-blocks as I remember .

CCR or Continuity of Care Record is a standard meant to ease the exchange of clinical information with a relatively easy to read and practical data-format and schema. There is ton of great information about CCR on its resource site. CCR document format is supported by majority of personal Health clouds, both – Microsoft HealthVault & Google Health.

The CCR specification comprises an implementation guide, XML schema definition and a guidance spreadsheet for each data element that makes up the standard. These resources can be bought from ASTM.

The document format of CCR is very straight forward, consisting of a header, body and a footer with the following top-level elements:

Google Health supports only a limited set of entities from the above, while HealthVault supports the entire standard and also allows transformation of some of these entities in to native HealthVault types. You can read more about working with CCR in HealthVault and various input mappings, output mappings, and CCR vocabularies.

Here are some illustrative CCR figures from Dr. Waldren’s presentation (see end of article).

Using the SNOMED-CT concepts one can write the Systolic Blood pressure reading in CCR as the following (UPDATE: Well-formatted the CCR to include source, object-id and actors, thanks to Matt Wagner):

<?xml version="1.0" encoding="utf-8"?>
<ContinuityOfCareRecord xmlns='urn:astm-org:CCR'>
  <CCRDocumentObjectID>Doc</CCRDocumentObjectID>
  <Language>
    <Text>English</Text>
  </Language>
  <Version>V1.0</Version>
  <DateTime>
    <ExactDateTime>2008</ExactDateTime>
  </DateTime>
  <Patient>
    <ActorID>Patient</ActorID>
  </Patient>
  <Body>
    <VitalSigns>
      <Result>
        <CCRDataObjectID>0001</CCRDataObjectID>
        <Description>
          <Text>Blood Pressure</Text>
        </Description>
        <Source>
          <Description>
            <Text>Unknown</Text>
          </Description>
        </Source>
        <Test>
          <CCRDataObjectID>0002</CCRDataObjectID>
          <Description>
            <Text>Systolic</Text>
            <Code>
              <Value>163030003</Value>
              <CodingSystem>SNOMEDCT</CodingSystem>
            </Code>
          </Description>
          <Source>
            <Description>
              <Text>Unknown</Text>
            </Description>
          </Source>
          <TestResult>
            <Value>120</Value>
            <Units>
              <Unit>mmHg</Unit>
            </Units>
          </TestResult>
        </Test>
        <Test>
          <CCRDataObjectID>0003</CCRDataObjectID>
          <Description>
            <Text>Diastolic</Text>
            <Code>
              <Value>163031004</Value>
              <CodingSystem>SNOMEDCT</CodingSystem>
            </Code>
          </Description>
          <Source>
            <Description>
              <Text>Unknown</Text>
            </Description>
          </Source>
          <TestResult>
            <Value>75</Value>
            <Units>
              <Unit>mmHg</Unit>
            </Units>
          </TestResult>
        </Test>
      </Result>
    </VitalSigns>
  </Body>
  <Actors>
    <Actor>
      <ActorObjectID>Patient</ActorObjectID>
      <Person>
        <Name>
          <CurrentName>
            <Given>John</Given>
            <Family>Doe</Family>
          </CurrentName>
        </Name>
      </Person>
      <Source>
        <Description>
          <Text>Unknown</Text>
        </Description>
      </Source>
    </Actor>
  </Actors>
</ContinuityOfCareRecord>

Note CodingSystem element. It allows CCR to interpret various medical vocabularies.

Relevant Tools:

(Thanks to Kathleen Connor)

• The CCR Validator, is an important resource to test/validate a CCR instance, is a now available  Not only does it validate the CCR against the XSD but also the constraints of the implementation guide.
• An Open Source StyleSheet to view CCR files.
• CCR to CCD & HL7 Mappers – tools which Map CCR to CCD and HL7 V2 & V3. You can access them directly here.
• Application to embed CCR in PDF-HealthCare.

Related Article(s):

• To get familiar with CCR I would highly recommended this 13 minute video by Dr. Steve Waldren.
• Adam Bosworth posted an interesting read on standards, his take (simple, human readable, focus on known structured data, etc.) favors CCR.

In this series:

1. Understanding Vocabularies. Wait! What did you say?
2. Understanding Vocabularies #2 – HealthVault Recommendations
3. Understanding SNOMED CT
4. Understanding CCR

I’m going to describe how this capability of reading an application’s certificates from the file store could be used to run HealthVault application on Windows Azure. Here are the steps to get a simple HealthVault application (which I call HelloHV) running on Windows Azure:

1. Install the Azure SDK and HealthVault SDK. Create your HealthVault application as a Web Role.
2. Configure and create an HealthVault application using the application manager utility in HealthVault SDK. Make sure you set the Action-Url to http://<yourapp>.cloudapp.net/Redirect.aspx  using the Application Configuration Center.
3. Copy the Redirect.aspx & Redirect.cs from HealthVault samples (HelloWorld in HealthVault SDK) in to your application and add reference to HealthVault assemblies (you can find them in C:\Program Files\Microsoft HealthVault\SDK\DotNet\Assemblies)
4. Add the HealthVault related config settings to your WebRole’s Web.Config, the easiest way to do this would be copy the relevant key(s) from a sample in HealthVault SDK. Here is an illustration :

   <appSettings>
     <add key="ApplicationId" value="01e21bd1-cb13-40d6-8f01-596286827d6d"/>
     <add key="ShellUrl" value="https://account.healthvault-ppe.com/"/>
     <add key="HealthServiceUrl" value="https://platform.healthvault-ppe.com/platform/"/>
     <!-- when we call the SignOut() method on HealthServicePage,
          it redirects us to the page below -->
     <!--<add key="NonProductionActionUrlRedirectOverride" value="Redirect.aspx" />-->
     <!-- The redirect page (specified above) uses these keys below to redirect to different
          pages based on the response from the shell -->
     <add key="WCPage_ActionHome" value="default.aspx"/>
     <add key="WCPage_ActionAppAuthSuccess" value="HelloHV.aspx"/>
     <add key="ApplicationCertificateFileName"
          value="~\cert\WildcatApp-01e21bd1-cb13-40d6-8f01-596286827d6d.pfx"/>
   </appSettings>

5. While testing on your local machine uncomment the following line in the Web.Config, this will allow HealthVault to communicate with your local machine. However make sure that this is commented when you publish the application.  Alternatively the following key can also be stored in UserApplicationConfigs.xml, if you maintain one for your development.

   <!--<add key="NonProductionActionUrlRedirectOverride" value="Redirect.aspx" />—->

   Gotacha1: Windows Azure changes the port numbers for your application so its hard to make it work without using the action-url configured for your application in Application Configuration Center.

6. In your Default HealthVault Page Make sure you read the certificate for your application from a local file (you can also use Azure Storage).

   Gotacha2: HealthVault SDK expects the ApplicationCertificateFileName to be absolute filename, this is impossible to determine for a cloud system like Azure. However we can get the absolute path by changing the value of the key at run-time.

   
   public partial class HelloHV : HealthServicePage
   {
       protected void Page_PreInit(object sender, EventArgs e)
       {
           ConfigurationSettings.AppSettings["ApplicationCertificateFileName"] =
               MapPath(@"~\cert\WildcatApp-01e21bd1-cb13-40d6-8f01-596286827d6d.pfx");
       }
   
       protected void Page_Load(object sender, EventArgs e)
       {
   
   ..
   

7. Hit Run and see your Hello HealthVault  application in action!!

Now the show time:

Check out a simple (HelloHV application) running on Windows Azure here.

The associated code for this application is shared here.

Remember to switch to SSL and secure your application certificate (using password or Azure Storage) before you consider taking an application running on Windows Azure live as a production HealthVault application.

SNOMED-CT includes:

• Terms or synonyms relating to a clinical concept
• Links between different concepts

To give you a taste here is an example of Blood pressure reading represented using SNOMED-CT from the linked paper (“Towards semantic interoperability in healthcare: ontology mapping from SNOMED-CT to HL7 version 3”, Amanda Ryan):

In addition to having a model to represent concepts and linkages the biggest draw of SNOMED CT is a staggering number of coded qualifiers (which belong to one concept or other). According to IHTSO there are about 311,000 actively used SNOMED CT concepts.

You can register for SNOMED CT here. Its free for companies and individuals in United States, however your registration is processed by NLM and it might take over 3 days to receive a confirmation and access.

Once you are through with registration and have an account, start by downloading the core subset of SNOMED CT concepts here, this list consists of about 5000 most frequently used terms by institutions across US. Its a good set to get familiar with, it consists of the following concept area:

• Clinical finding        : 4,550 codes in total
• Procedure            :   414 codes in total
• Situation with explicit context    :   132 codes in total
• Event                :    38 codes in total
• Body structure            :    46 codes in total
• Social context            :     2 codes in total

We can use BCP to copy the files from SNOMED CT Core in to our local database, and do more interesting queries & data analysis like find distribution on these terms, co-relate problems vs. findings and of course work on the larger SNOMED CT database to find synonyms etc.; but I’ll keep that for another day. Here very quickly I’ll show how one can use a web-based browser, Snowflake, http://snomed.dataline.co.uk/ (requires registration) to lookup a SNOMED code and see what else it relates to. We can see that in line 3 above SNOMED CT concept 10085004 is marked as Metatarsalgia (finding), however using the Snowflake browser we can see in that in addition to being a finding this concept is a problem as well.

This was just tip of the ice-berg, please leave comments for future posts / areas to consider in the Ontology domain.

Further reading / relevant links:

• LexGrid: Wiki

In this series:

1. Understanding Vocabularies. Wait! What did you say?
2. Understanding Vocabularies #2 – HealthVault Recommendations
3. Understanding SNOMED CT

Earlier this year I had made a post about tracking Swine Flu using Ushahidi’s software. Various folks online have tried to help raise awareness of the pertinent epidemic, most noticeably CDC has launched a comprehensive website flu.gov to inform us better. Microsoft has launched the H1N1 Response Center and Google is helping through Flu trends.

Most common flu is the seasonal flu, which every year takes a toll of about 36,000 lives from late fall (Nov) to early Spring (March) and effects about 5-20 percent of population. This season we have a risk for a getting hit by swine flu (H1N1) which can cause more deaths, and there is an even deadlier version – the avian flu (H5N1).

So what should you do?

• Wash your hands and avoid close contact with sick people.
• Consider taking the Flu shot from a facility near you
• If you feel Flu, take a Flu assessment powered by HealthVault .
• Spread Flu Awareness – may be use the widget below:

Here is the code to copy this widget to your blog / website:

<iframe height="200" src="http://www.reemedix.com/misc/fluwidget.html"
    frameborder="0" width="300" scrolling="no">
</iframe>

There are quite a few challenges with regards to HealthVault SDK to work in this realm. The standard HealthServicePage no longer works in a controller paradigm. Eventually the SDK will need to provide a HealthServiceController, but until then I’ll try and explain how we can use the current SDK to work in an ASP.NET MVC world.

As I have explained earlier in my ruby series HealthVault authenticates an application in three contexts – anonymous, the application itself and the application in presence of user information. In this series I will try to take the same approach and explain how we can do the same with ASP.NET MVC.

It’s relative easy to talk to HealthVault via the anonymous GetServiceDefination method. Here is the heart of the code which enables this:

   1: public ActionResult Index()

   2: {

   3:     ViewData["Message"] = "Welcome to HealthVault ASP.NET MVC!";

   4:     

   5:     // Do an anonymous connection with HealthVault using the Hello World application id

   6:     ApplicationConnection appConnection = new ApplicationConnection(

   7:         new Guid("05a059c9-c309-46af-9b86-b06d42510550"),

   8:         "https://platform.healthvault-ppe.com/platform/");

   9:     // Get the service defination from HealthVault platform

  10:     ServiceInfo sInfo = appConnection.GetServiceDefinition();

  11:     // Pass the data for viewing

  12:     ViewData["ServiceInfo"] = sInfo.HealthServiceUrl.ToString();

  13:     return View();

  14: }

Next time: How to authenticate your application with HealthVault through ASP.NET MVC

Disclaimer: Please note this is not a definitive or complete list, and I will update the table as I discover inconsistencies. The definitive source are the XSDs associated with HealthVault data types.

As  you can notice above we recommend ICD-9, RxNorm, LOINC, NDC. x12-de-1130, x12-de-335. We do prefer SNOMED-CT as well, however the application using it need to have license for it.

Having written the above I would like to match that with what Dr. Halamka recommends in his post. Note that I mention content column for completeness, however its not useful for comparison.

Next Time: I’ll try to update the above tables with more details and try to come with recommendations of which clinical type (in the Data column above) would potentially match with which HealthVault type.

As usual leave your suggestions in the comments.

The Syncing Philosophy
Microsoft provides a sync framework which solves the problem of syncing between various data sources elegantly. However the framework is largely designed for data which is sourced using multiple masters, in WalkMe’s case we simplify this and consider HealthVault to be the master data source. Given that HealthVault is our master data source we radically simplify the complexity of syncing and don’t need to employ the services of sync framework.

To make HealthVault as the master data source any data input from WalkMe is always entered in HealthVault first and then the WalkMe database syncs with HealthVault

The Data Model
In WalkMe’s case it maintains a local database of all its users and their data with regards to aerobic exercise session and exercise. I’ll keep the discussion about where to look for which data in HealthVault data types context for some other day. So why does WalkMe need a local database? We need a local database to maintain running totals of a users total steps, weekly steps and yearly steps. Also various analytical, notificational and graphical tools are only able to run in context of local data.

For each HealthVault user WalkMe keeps the following in the database:

• HealthVault Person Id – This is unique to each person.
• HealthVault Record Id – This is unique to each record Id, since WalkMe is a single record application (doesn’t work on multiple records associated with a person at a time), the record id has one to one mapping with the WalkMe user id
• Last Sync Time with HealthVault – The time at which this user last synched with HealthVault. We will discuss the tuning aspects of sync time later in the mechanics section.
• Last Sync Entity – Who performed the last sync. We will discuss various sync mechanism WalkMe we employs in the mechanics section.
• Last Sync Status – Details about the sync status. This is helpful to reform the sync or flag whether the sync is in progress.

For each activity (aerobic exercise session and exercise) entry for each user, WalkMe keeps the following in the database:

• HealthVault Item Id – This is the GUID of the item (any HealthVault thing). The contents of this HealthVault item are stored in this particular activity row. The content in our case are – steps, aerobic steps, calories, distance.
• Updated_at – This is the time at which this item was last updated.

For each sync job / activity we maintain a database table having:

• sync server name
• sync status
• sync timestamp
• sync frequency (in hours)
• sync job id
• sync msg

Fig1. Relevant Parts Of WalkMe Data Model

The Mechanics
The key aspects to understand in any sync problem is when is it that your user will need the most up to date information and how are they going to access it. Other than the time when a user is directly logged in the application, WalkMe’s needs the most up to date information when showing the WalkMe pedometers (which exist outside the context of WalkMe and HealthVault and they are accessed via a public webpage). Other key piece is for the WalkMe groups to show the most up to date information with regards to the leaders in the group they need each users data to be synched at least in last 24 hours.

So I can summarize that we have the following three scenarios needing the most up to date HealthVault data:

1. When the user in logged in the application – data needed to show his analytics, and standings in age-group, BMI, Zip etx.
2. When the user pedometer is accessed from a public page – data needed to show the most recent steps.
3. When the user accesses their group page – the current standings of participants should be up to date at least as of last 24 hours.

When and How to Sync
Clearly for scenarios 1 and 2 above we need to sync for a single user while for scenario #3 (and a part of #2) we need to sync the entire list of application users. Also note that for scenario 1 the user is present and for scenario 2 the user is not online. Lets name them #1 is UserOnlineSync #2 is UserOfflineSync and #3 is ApplicationSync.

UserOnlineSync : We should sync it every 20 minutes (based on a cookie) and sync the account when the user signs in.

UserOfflineSync: This sync should be done as requested but in the context of this sync user is not online (This is done using HealthVault offline calls). However the frequency is deteremined by output caching enabled on the widgets (I would put that to 20 minutes as well).

ApplicationSync: This is done for all the user and typically by a background process the last table in the data model is primarily meant for this process. However we don’t want to ping HealthVault for all the records so we use the method GetUpdateRecordsForApplication. The background process can run once or twice a day the frequency of the same can be made configurable.

Please note application sync is not fully functional in WalkMe yet owing to resource constraints on background processes in our hosting environment.

What to do when things go wrong?
As you will note in the above three sync mechanisms are primarily tailored to be partial syncs i.e they dont fetch all the user activities all the time. So what happens if a user deletes an entry in HealthVault or lets say the sync never completed? Well the user will see discrepancy is his/ her record and in that case we provide a mechanism for them to do a full sync with HealthVault. The idea of full sync being that all the current items are deleted and all the items form the users HealthVault record are imported again, and of course all the totals are re-calculated. In addition to taking care of uncompleted syncs this process also account for deleted items (there is not other way for delete items to be communicated). This is a powerful “reset” button and is exposed to the user with caution.

The Implementation

 
Here is some code showing the implementation of above three sync mechanisms with full and partial syncs. Please take it with grain of salt its here for illustrative purposes only and is no way meant to be used as is.

• UserOnlineSync

   1: public static void OnlineSyncUser(ProfileModel profile, PersonInfo info, bool partialSync)

   2:  {

   3:      string syncType = "partial";

   4:      DateTime? lastSyncTime = profile.UserCtx.hv_last_sync_time;

   5:      DateTime timeStamp = DateTime.Now;

   6:  

   7:      // reset lastsynctime if this is a full sync

   8:      if (!lastSyncTime.HasValue || !partialSync)

   9:      {

  10:          WlkMiTracer.Instance.Log("HVSync.cs:OnlineSyncUser", WlkMiEvent.UserSync,

  11:                WlkMiCat.Info, string.Format("Full syncing for User: {0}",

  12:                  profile.UserCtx.user_id));

  13:          lastSyncTime = null;

  14:      }

  15:  

  16:      // Retrieve the latest info from HealthVault

  17:      HealthRecordItemCollection items = 

  18:          GetHVItemsOnline(info, lastSyncTime);

  19:      if (items != null && items.Count > 0)

  20:      {

  21:          foreach (HealthRecordItem item in items)

  22:          {

  23:              // Do the distinct per item work

  24:              ProcessStepsHealthItem(item, profile);

  25:          }

  26:      }

  27:  

  28:      //only update the last sync time if we are able to download items

  29:      if (items != null)

  30:      {

  31:          //set last sync time

  32:          profile.UserCtx.hv_last_sync_time = timeStamp;

  33:          profile.Save();

  34:      }

  35:  

  36:      // Clear the WlkMi data cache if the last sync is null or this is a full sync

  37:      if (!lastSyncTime.HasValue || !partialSync)

  38:      {

  39:          WlkMiTracer.Instance.Log("HVSync.cs:OnlineSyncUser", WlkMiEvent.UserSync,

  40:                WlkMiCat.Info, string.Format("Full sync deleting information for User: {0}",

  41:                  profile.UserCtx.user_id));

  42:          lastSyncTime = null;

  43:          WalkLogModel.ClearUserCache(profile);

  44:          syncType = "full";

  45:      }

  46:  

  47:      //Processtotals for this user

  48:      WalkLogModel.ProcessTotals(profile.UserCtx.user_id);

  49:      

  50:      WlkMiTracer.Instance.Log("HVSync:OnlineSyncUser", WlkMiEvent.UserSync,

  51:          WlkMiCat.Info, string.Format("Completed Online {1} Sync of User: {0}",

  52:          profile.UserCtx.user_id.ToString(), syncType));  

  53:  }

  54:  

  55: public static HealthRecordItemCollection GetHVItemsOnline(PersonInfo info, DateTime? lastSync)

  56: {

  57:     HealthRecordSearcher searcher = info.SelectedRecord.CreateSearcher();

  58:  

  59:     HealthRecordFilter filter = new HealthRecordFilter(Exercise.TypeId,

  60:         AerobicSession.TypeId);

  61:  

  62:     if(lastSync.HasValue)

  63:         filter.UpdatedDateMin = (DateTime) lastSync;

  64:  

  65:  

  66:     // TODO: Add filter so that we get only items with steps

  67:     searcher.Filters.Add(filter);

  68:     HealthRecordItemCollection items = searcher.GetMatchingItems()[0];

  69:  

  70:     return items;

  71: }

• UserOfflineSync

   1: public static void OfflineSyncUser(ProfileModel profile)

   2: {

   3:     DateTime timeStamp = DateTime.Now;

   4:  

   5:     // Retrieve the latest info from HealthVault

   6:     if (profile.UserCtx.hv_personid != null)

   7:     {

   8:         HealthRecordItemCollection items = GetHVItemsOffline(profile.UserCtx.hv_personid, 

   9:             profile.UserCtx.hv_recordid,profile.UserCtx.hv_last_sync_time);

  10:         if (items != null && items.Count > 0)

  11:         {

  12:             foreach (HealthRecordItem item in items)

  13:             {

  14:                 // Do the distinct per item work

  15:                 ProcessStepsHealthItem(item, profile);

  16:             }

  17:             WlkMiTracer.Instance.Log("HVSync.cs:OfflineSyncUser", WlkMiEvent.AppSync,

  18:                 WlkMiCat.Info, string.Format("Number of items retrieved from HV: {0}",

  19:                 items.Count));

  20:         }

  21:         //only update the last sync time if we are able to download items

  22:         if (items != null)

  23:         {

  24:             //set last sync time

  25:             profile.UserCtx.hv_last_sync_time = timeStamp;

  26:             profile.Save();

  27:         }

  28:     }

  29:  

  30:     // Clear the WlkMi data cache if the last sync is null

  31:     // In other words, you can also set the time stamp for user's last sync to null

  32:     // to trigger a full offline sync.

  33:     // TODO: Consider not doing this for production

  34:     if (!profile.UserCtx.hv_last_sync_time.HasValue)

  35:     {

  36:         WlkMiTracer.Instance.Log("HVSync.cs:OfflineSyncUser", WlkMiEvent.AppSync,

  37:             WlkMiCat.Info, string.Format("Deleting information for user {0}",

  38:             profile.UserCtx.user_id));

  39:  

  40:         WalkLogModel.ClearUserCache(profile);

  41:     }

  42:  

  43:     // Processtotals for this user

  44:     WalkLogModel.ProcessTotals(profile.UserCtx.user_id);

  45:  

  46:     WlkMiTracer.Instance.Log("HVSync.cs:OfflineSyncUser", WlkMiEvent.AppSync,

  47:         WlkMiCat.Info, string.Format("Completed Offline Sync of User: {0}",

  48:         profile.UserCtx.user_id.ToString()));

  49: }

  50:  

  51: public static HealthRecordItemCollection GetHVItemsOffline(Guid personId, 

  52:     Guid recordGuid, DateTime? lastSync)

  53: {

  54:     // Do the offline connection

  55:     OfflineWebApplicationConnection offlineConn =

  56:         new OfflineWebApplicationConnection(personId);

  57:     offlineConn.RequestTimeoutSeconds = 180;  //extending time to prevent time outs for accounts with large number of items

  58:     offlineConn.Authenticate();

  59:     HealthRecordAccessor accessor =

  60:         new HealthRecordAccessor(offlineConn, recordGuid);

  61:     HealthRecordSearcher searcher = accessor.CreateSearcher();

  62:  

  63:     HealthRecordFilter filter = new HealthRecordFilter(Exercise.TypeId,

  64:         AerobicSession.TypeId);

  65:  

  66:     if (lastSync.HasValue)

  67:         filter.UpdatedDateMin = (DateTime)lastSync;

  68:  

  69:     searcher.Filters.Add(filter);

  70:  

  71:     HealthRecordItemCollection items = null;

  72:     try

  73:     {

  74:         items = searcher.GetMatchingItems()[0];

  75:     }

  76:     catch (Exception err)

  77:     {

  78:         WlkMiTracer.Instance.Log("HVSync.cs:GetHVItemsOffline", WlkMiEvent.AppSync, WlkMiCat.Error,

  79:                 string.Format("Error for user {0} : {1} ", 

  80:                 recordGuid.ToString(),err.ToString()));

  81:     }

  82:     return items;

  83: }

• ApplicationSync

   1: public static void SyncWlkMiWithHealthVault(

   2:     DateTime? lastUpdatedDate)

   3: {

   4:     WlkMiTracer.Instance.Log("HVSync.cs", WlkMiEvent.AppSync, WlkMiCat.Info, 

   5:         "Getting updated records from HealthVault");

   6:     // Do the offline connection

   7:     OfflineWebApplicationConnection offlineConn =

   8:         new OfflineWebApplicationConnection();

   9:     offlineConn.Authenticate();

  10:     IList<Guid> updatedUserIds = 

  11:         offlineConn.GetUpdatedRecordsForApplication(lastUpdatedDate);

  12:     WlkMiTracer.Instance.Log("HVSync.cs", WlkMiEvent.AppSync, WlkMiCat.Info,

  13:         string.Format("Got {0} updated records from HealthVault", updatedUserIds.Count));

  14:  

  15:     foreach(Guid recordid in updatedUserIds)

  16:     {

  17:         ProfileModel syncUser = ProfileModel.Fetch(recordid);

  18:         if (syncUser == null)

  19:         {

  20:             WlkMiTracer.Instance.Log("HVSync.cs", WlkMiEvent.AppSync, WlkMiCat.Error,

  21:                 string.Format("No WlkMi user found for recordif {0} ", recordid));

  22:             continue;

  23:         }

  24:         // Decide to update this guy?

  25:         if (syncUser.UserCtx.hv_last_sync_time > DateTime.Now.AddSeconds(

  26:             -Constants.UserSyncIntervalInSeconds))

  27:         {

  28:             WlkMiTracer.Instance.Log("HVSync.cs", WlkMiEvent.AppSync, WlkMiCat.Info,

  29:                 string.Format("Skipping sync for user {0} ", syncUser.UserCtx.user_id));

  30:         }

  31:         else

  32:         {

  33:             HVSync.OfflineSyncUser(syncUser);

  34:         }

  35:     }

  36: }

Suggestions?

There are various ways in which the HealthVault platform can assist application in syncing with the data native to HealthVault. One thing comes to my mind is support for feedsync. You may have a lot of suggestions, please feel free to chime in the comments!!

1. Sign-In the WalkMe HealthVault application
2. Click on the “Share” tab
3. Make sure the “Allow Other to see my WalkMe data” checkbox is checked
4. If you check the box the page refreshes, saying Sharing is turn on
5. Scroll to the bottom of the page – to Share your steps as an image option
6. Click on file part of “Save this file as your outlook signature”
7. Save the walkme.htm file in your C:\Users\[YourUserName]\AppData\Roaming\Microsoft\Signatures director. Please note the part after [YourUserName] of this directory is hidden and you will manually need to type it in your Windows explorer to get to the full directory. Let me know if you can’t locate this directory on Windows systems other Vista or Seven (it should be under C:\Documents & Settings\[YourUserName]\Application Data\Roaming\Microsoft\Signatures on Windows XP).
8. To test the signature open Outlook and and create new mail. Click on the “Signature” part of ribbon (outlook 2007) and you will see WalkMe in drop down. If you select WalkMe signature you should see something like below in your outlook email : 

Enjoy your walking and keep yourself motivated by communicating your live pedometer through the signature.