c# - 试图从Polar H10获得心率变异性[蓝牙低能耗样本UWP]

Question

我正在与Polar H10一起从中获取心率变异性。

我正在从Microsoft运行Bluetooth Low Energy Sample。

我已使用此样本从另一个极性设备(Polar OH1)获取心率，并且效果很好。

但是现在我想从Polar H10获得HRV。但是BLE示例代码并没有真正向我展示它应该像心率一样的HRV特征。

这些是我看到的唯一特征:

 // first layer keys are serviceUuid's
// second layer keys are characteristicUuid's
// with their respective name/description as values
{
    "1800"    /* Generic Access */                      : {
    "2a00": "Device Name",
    "2a01": "Appearance",
    "2a02": "Peripheral Privacy Flag",
    "2a03": "Reconnection Address",
    "2a04": "Peripheral Preferred Connection Parameters"
},
"1801"    /* Generic Attribute */                   : {
    "2a05": "Service Changed"
},
"180d"    /* Heart Rate */                          : {
    "2a37": "Heart Rate Measurement",
    "2a38": "Body Sensor Location"
   // This is where it should show Heart Rate Variability //
},
"180a"    /* Device Information */                  : {
    "2a23": "System ID",
    "2a24": "Model Number String",
    "2a25": "Serial Number String",
    "2a26": "Firmware Revision String",
    "2a27": "Hardware Revision String",
    "2a28": "Software Revision String",
    "2a29": "Manufacturer Name String"
},
"180f"    /* Battery Service */                     : {
    "2a19": "Battery Level"
},
"6217ff4b-fb31-1140-ad5a-a45545d7ecf3" /* unknown */: {
    "6217ff4c-c8ec-b1fb-1380-3ad986708e2d": "unknown", /* read:true */ // value = 
     uInt16Array [3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
    "6217ff4d-91bb-91d0-7e2a-7cd3bda8a1f3": "unknown" /* write:true, 
     indicate:true, descriptors:{ descriptorUuid: "2902" }*/
 {
     /* 6172 */
     this service has all the numbers which I have no idea about. 
     Example: 10905, 10906, and etc.  
  }
}

有谁知道我应该对代码进行哪些调整才能获得HRV？

                 **EDIT::** 


           private static ushort ParseHeartRateValue(byte[] data)
    {

        // Heart Rate profile defined flag values
        const byte heartRateValueFormat = 0x01;

        byte flags = data[0];
        bool isHeartRateValueSizeLong = ((flags & heartRateValueFormat) != 0);

        if (isHeartRateValueSizeLong)
        {
            return BitConverter.ToUInt16(data, 1);
        }
        else
        {
            return data[1];
        }
    }

////以上方法更新后//////

          private static ushort ParseHeartRateValue(byte[] data)
    {
        ushort offset = 1;
        // Heart Rate profile defined flag values
        const byte heartRateValueFormat = 0x01;

        byte flags = data[0];
        bool rr = (flags & (1 << 4)) != 0;
        if (rr)
        {
            int count = (data.Length - offset) / 2;
            for (int i = 0; i < count; i++)
            {

                ushort value = BitConverter.ToUInt16(data, offset);

                double intervalLengthInSeconds = value / 1024.0;
                offset += 2;
            }
        }
        bool isHeartRateValueSizeLong = ((flags & heartRateValueFormat) != 0);

        if (isHeartRateValueSizeLong)
        {
            return BitConverter.ToUInt16(data, 1);
        }
        else 
        {
            return data[1];
        }

    }

Answer 1

您使用的设备遵循心率蓝牙规范。因此，它发送的数据应遵守该标准。如果引用this documentation，您将阅读问题中列出的0x2A37特性，但不应将其作为整数接收。

我链接的文档中列出了特性给出的不同值。我认为您会对“RR间隔”感兴趣，它的分辨率为1/1024秒。

您将需要从您的值中检索所需的字节。注意字节顺序。如文档所述:

The fields in the above table are in the order of LSO to MSO. Where LSO = Least Significant Octet and MSO = Most Significant Octet.

因此，您正在寻找该值的最后2个字节，因为RR间隔是一个uint16。