Wearable electronic device

1. An apparatus comprising:

an elongated apparatus structure configured to fit around a body part of a user;

an actuator configured to change shape of the elongated apparatus structure; and

at least one sensor,

wherein the actuator is configured to automatically tighten the elongated apparatus structure around the body part of the user in response to initiating collection of data by the sensor and automatically loosen the elongated apparatus structure around the body part of the user in response to ending the collection of data by the sensor.

2. The apparatus according to claim 1 , wherein the actuator is configured to tighten the elongated apparatus structure around the body part of the user based on an action the apparatus is performing, and wherein the action comprises detecting a need to provide the user with an alert.

3. The apparatus according to claim 1 , wherein the actuator is configured to loosen the elongated apparatus structure around the body part of the user based on an action the apparatus is performing, and wherein the action comprises an action other than ending the collection of data by the sensor.

4. The apparatus according to claim 1 , wherein the sensor is configured to measure heart rate or skin moisture or blood pressure.

5. The apparatus according to claim 1 , wherein the actuator is configured to change tightness of the elongated apparatus structure around the body part of the user as an indication of activity in the apparatus.

6. The apparatus according to claim 1 , wherein the actuator comprises shape memory material.

7. The apparatus according to claim 1 , wherein the actuator comprises a motor.

8. The apparatus according to claim 1 , further comprising a user interface unit.

9. The apparatus according to claim 1 further comprising

a memory;

a communications unit; and

a processing unit.

10. The apparatus according to claim 9 , wherein the processing unit is configured to control the actuator to change tightness of the elongated apparatus structure around the body part as an indication of activity in the processing unit.

11. The apparatus according to claim 9 , wherein the processing unit and the elongated apparatus structure are physically separate and the processing unit is configured to control, over a wireless communication connection, the actuator to change tightness of the elongated apparatus structure around the body part.

12. The apparatus according to claim 9 , wherein the actuator is configured to change tightness of the elongated apparatus structure around the body part of the user as an indication of an incoming call or message received at the communications unit.

13. A method comprising:

controlling an apparatus comprising a sensor, an elongated apparatus structure configured to fit around a body part of a user and an actuator configured to change shape of the elongated apparatus structure; and

controlling the actuator to automatically tighten the elongated apparatus structure around the body part of the user in response to initiating collection of data by the sensor and automatically loosen the elongated apparatus structure around the body part of the user in response to ending the collection of data by the sensor.

14. The method according to claim 13 , further comprising tightening the elongated apparatus structure around the body part of the user based on an action the apparatus is performing, wherein the action comprises detecting a need to provide the user with an alert.

15. The method according to claim 13 , further comprising loosening the elongated apparatus structure around the body part of the user based on an action the apparatus is performing, wherein the action comprises an action other than ending the collection of data by the sensor.

16. The method according to claim 13 , further comprising changing tightness of the elongated structure around the body part as an indication of activity in a processing unit of the apparatus.

17. The method according to claim 13 , further comprising changing tightness of the elongated apparatus structure around the body part of the user as an indication of an incoming call or message.