Energy-efficient collection of wearable sensor data
A wearable garment with sensors attached to obtain physiological data. The sensors are incorporated to form a body area sensor network to obtain the data. This provides patients with improved health monitoring by aggregating multiple interconnected nodes on a human body for sensorimotor measurements and provides patients with quantitative measurements of their progress. The data is obtained in a way that allows for the number of transmissions to be reduced thereby conserving the energy of the wearable devices. This is made possible by each sensor reducing the number of samples by eliminating predictable samples and configuring the sensors to pack the data efficiently. A neural network can determine whether a sample can be skipped or needs to be reported. A long short term memory architecture creates a waveform for a given snapshot of samples based on the previous samples regardless of whether these samples were reported or predicted.
1 . A body area sensor network apparatus comprising:
a mesh of sensors that are networked and that are each configured to sample data related to one or more of full range of motion, muscle activation, and body vitals, creating a set of samples at each sensor;
wherein each sensor is configured to reduce the number of its samples by eliminating predictable samples in the set of samples, producing a set of remaining samples;
wherein each sensor is further configured to pack the set of remaining samples into a minimized combined payload;
wherein each sensor is configured to transmit the minimized combined payload; and
wherein the packing of the set of remaining samples comprises:
forming the minimized combined payload comprising the following fields:
a sample size specifying a number of bits in each sample in the minimized combined payload;
a sample count specifying a number of samples in the minimized combined payload;
a skip indicator field specifying which samples are eliminated and which samples are remaining samples; and
a plurality of remaining samples where eliminated samples are absent.
2 . The apparatus of claim 1 , wherein the skip indicator field comprises a bit for each sample where:
the bit is 1 if the sample is a remaining sample in the combined payload, and 0 if the sample is eliminated from the minimized combined payload.
3 . The apparatus of claim 1 wherein the minimized combined payload represents a snapshot of T consecutive samples, wherein T is optimized to minimize N and W in the equation
W=[N×P max −(┌log 2 S┐+T +┌log 2 T ┐)− T×S]/N
where
W is an amount of utilized space,
N is a packet count,
P max is a largest allowed payload, and
S is a number of bits needed per sample.
4 . The apparatus of claim 1 wherein a size of a sample is minimized adaptively while preserving precision of a signal represented by the sample.
5 . The apparatus of claim 4 wherein the sample size minimization comprises denormalizing a floating point representation of the signal.