• Aucun résultat trouvé

Power-and Delay-Aware Mobile Application-Data Flow Adaptation: the MobiHealth system case study

N/A
N/A
Protected

Academic year: 2022

Partager "Power-and Delay-Aware Mobile Application-Data Flow Adaptation: the MobiHealth system case study"

Copied!
21
0
0

Texte intégral

(1)

Conference Presentation

Reference

Power-and Delay-Aware Mobile Application-Data Flow Adaptation:

the MobiHealth system case study

WAC, Katarzyna, et al.

Abstract

Emerging healthcare applications rely on personal mobile devices to monitor patient vital signs and to send it to the hospitals-backend servers for further analysis. However, these devices have limited resources that must be used optimally in order to meet the requirements of healthcare applications end-users: healthcare professionals and their patients. This paper reports on a case study of a cardiac telemonitoring application delivered by the so-called MobiHealth system. This system relies on a commercial device with multiple (wireless) network interfaces (NI). Our study focuses on how the choice of a NI affects the end-to-end applicationpsilas data delay (extremely important in case of patientpsilas emergency) and the energy consumption of the device (relating to the service sustainability while a patient is mobile). Our results show the trade-off between the delay and battery savings achieved by various NI activation strategies in combination with application-data flow adaptation. For a given mobile device, our study shows a gain of 40-90% in battery savings, traded against the higher delays (therefore applicable [...]

WAC, Katarzyna, et al. Power-and Delay-Aware Mobile Application-Data Flow Adaptation: the MobiHealth system case study. In: Proceedings of the 10th International Conference on e-health Networking, Applications and Services - HealthCom 2008, Singapore

(Singapore), 7-9 July 2008, 2008, p. 20

Available at:

http://archive-ouverte.unige.ch/unige:72670

Disclaimer: layout of this document may differ from the published version.

1 / 1

(2)

Kate WAC, HealthCom’08

Power- and Delay-Aware Mobile Application-Data Flow Adaptation

the MobiHealth system case study

Katarzyna Wac (Kate), PhD student

Pravin Pawar, Bert-Jan van Beijnum, Richard Bults Mortaza Bargh, Arjan Peddemors

(3)

Kate WAC, HealthCom’08

Outline

• Introduction

m-health services: from MobiHealth project to MobiHealthTM system

• Problem Description

telemonitoring service: battery consumption, delays vs. NI choice

• Approach

measurements-based performance evaluation of service for different NIs

• Conclusions & Recommendations

which NI choice is best for which application flow?

(4)

Kate WAC, HealthCom’08

Introduction

m-health services

from MobiHealth project to MobiHealth

TM

system

(5)

health tele-monitoring services

general practitioner Mobile Network

Operator

medical specialist

Internet

mobile patient (BAN-MBU)

healthcare centre

e.g. 2.5/3G, WLAN

MobiHealth project

MobiHealth™ System

(6)

Kate WAC, HealthCom’08

MobiHealth System History

2002-2004: MobiHealth – EU IST-2001-36006 (5 countries) m-health services: technically feasible? (emerging 2.5G/3G) 2005-2006: HealthService24 – EU eTEN-517352 (4 countries) m-health services: clinically/commercially feasible?

2004-2008: Freeband-Awareness – Dutch BSIK-5902390

m-health services: proactively context-aware? (security/privacy?) from 2007: MobiHealth BV – University of Twente (NL) spin-off commercial m-health services: platform for any sensor system?

2007-2009: Myotel – EU eTen-C046230 (4 countries)

telemonitoring/teletreatment services: chronic neck-shoulder pain?

(7)

Kate WAC, HealthCom’08

Problem Description

telemonitoring service:

battery consumption, delays vs. NIs status

(8)

Kate WAC, HealthCom’08

Problem description

Focus: explorative study

• mobile: limited processing, communication, storage, battery capacity

• mobile health services need to support emergency & non-emergency cases

• health telemonitoring service performance:

• data delay

• battery consumption

How to choose NI and parameterize application flow to

• match delay requirement to emergency/non-emergency case and

• minimize battery consumption

=f (NIs status)

(9)

Kate WAC, HealthCom’08

Approach

measurements-based performance evaluation

of telemonitoring service for different NIs

(10)

Kate WAC, HealthCom’08

Measurements Setup

MobiHealth™ system used

• cardiac patient case: 3 leads ECG, heart rate*, SpO2, pleth, alarm (128 Hz)

• MBU: Qtek 9090, Windows Mobile® 2003 (!battery drain!)

• main battery: Li-ion polymer 1490 mAh

• NI: Bluetooth (always ON gathering data from MOBI™)

• NI: WLAN (802.11b, OS ‘best-battery’ setting)

• NI: WWAN-GPRS (class 10: 4+1/3+2 slots)

• Application flow: 5-14 Bytes, 128Hz

• aggregation: 1 second of data

• compression (ZIP): 38-85 %

• TCP-IP end-to-end path

• continuous: ~1.2-1.5, 5.5 or 7.7 kbps

• bursts: 5.5 or 7.7 kbps, ~ Mbps

*heart rate is derived from 3 leads ECG

NI status: ON-IDLE-OFF

MOBI

MBU

(11)

Kate WAC, HealthCom’08

Approach: Measurements

Application-delay: App-RTT

• system response time for: telemonitoring/teletreatment

• does not require MBU & BEsys clocks synchronization

• MBU: measures it every 10 seconds

(12)

Kate WAC, HealthCom’08

Approach: Measurements

Remaining battery level (Windows Mobile

®

)

• MBU: measures every 5 seconds

(13)

Measurements setup

focus

BAN BEsys

(14)

Kate WAC, HealthCom’08

Selected Findings

(15)

NI choice: consumed battery capacity

Min: GPRS ON-ACTIVE, WLAN OFF

Max: WLAN ON-ACTIVE, GPRS ON-IDLE

(16)

NI choice: App-RTT delay

Min: WLAN ON-ACTIVE, GPRS ON-IDLE Max: GPRS ON-ACTIVE, WLAN OFF

(inverted to the battery profile!)

emergency

emergency (if no WLAN)

?

(17)

NI activation strategies: power efficiency

S-EM emergency

continuous flow: WLAN ON-ACTIVE, GPRS ON-IDLE (S-EM) bursty flow: WLAN OFF/ON-ACTIVE, GPRS OFF

patient reachable?

(18)

Kate WAC, HealthCom’08

Conclusions & Recommendations

telemonitoring service:

which NI choice is best?

(19)

Kate WAC, HealthCom’08

Conclusions & Recommendations

• GPRS vs WLAN have complementary profiles

• GPRS: power consumption lower, App-RTT higher than WLAN

• App-RTT vs power consumption

• minimal App-RTT if continuous application flow

• minimal power consumption if application flow in bursts

• ? WLAN App-RTT lower when GPRS ON-IDLE than when GPRS-OFF

• Optimal choices:

• emergency: continuous flow (App-RTT efficient)

• WLAN ON-ACTIVE (GPRS ON-IDLE)

• GPRS ON-ACTIVE (WLAN-OFF)

• non-emergency: bursty flow (power efficient)

• WLAN ON-ACTIVE/-IDLE (GPRS ON-IDLE) Æ n=4 seconds of data

• GPRS ON-ACTIVE/-IDLE (WLAN-OFF) Æ n=6 seconds of data

• larger n are not power-efficient enough to be considered (+ patient unreachable)

(20)

Kate WAC, HealthCom’08

Future work

• More measurements

• NI activation-deactivation (ON-OFF) and NI-NI WLAN-GPRS handovers

• multiple MBU-devices, NIs, different locations (mobile!) and times

• detailed study on delay variation as f(NI)

• multiple application data flows with different App-RTT requirements

• NI activation strategy vs.

• monetary cost of networks usage

• security considerations

• Further QoS/QoE considerations for the Mobihealth system

• requirements & provisions

• towards dependable system Æ dynamic system adaptation e.g. self-healing

(21)

Kate WAC, HealthCom’08

www.healthservice24.com www.mobihealth.org

www.awareness.freeband.nl www.myotel.eu

www.mobihealth.com

Thank You!

Références

Documents relatifs

How to organize the data flow of the City: a case study with the Spatial Data Infrastructure CartoPOLIS?.

Figure 1 illustrates how Insurable Object, Vehicle, Claim and Claim Folder entities can be defined in terms of attribute and can be linked to each other via relationships in

Maria-José Escorihuela, Yann H. Kerr, Andre Chanzy, Patricia de Rosnay, Jean-Pierre Wigneron. On the effective penetration depth of l-band radiometry and the validation of SMOS data:

3 depicts the cumulative distribution for the relative error committed by our solution (σ Dec ), as well as by the trivial solution (σ T rivial ) and by the Conditional method (σ

We propose a solution to estimate the first two moments of the end-to-end delay experienced by the packets of a flow in a wired network based only on delay measurements

The obtained results show that the method is generally good, with a relative error on the estimated standard deviation of the end-to-end delay usually close to 5%, though it may

Table 1: Estimated CO 2 from training a single French (Com- monVoice) or English (LibriSpeech) state-of-the-art end-to-end speech recognizer on Nvidia Tesla V100 GPUs2. Models CO

This observation of a discrepancy between what seems to be necessary to effectively manage risk (i.e. the managerialisation of field workers achieved through the