Opportunistic Medical Monitoring UsingBluetooth P2P Networks

Dae-Ki Cho, Seung-Hoon Lee, Alexander Chang, Tammara Massey, Chia-Wei Chang, Min-Hsieh Tsai,

Majid Sarrafzadeh and Mario Gerla

Department of Computer ScienceUniversity of California, Los Angeles

Outline• Motivation• Introduction• Bluetooth Overview• Patient Monitoring and Record Management

– NurseNet– BlueAlert

• Experiment• Simulation• Conclusion

2

Motivation• Gaining popularity of ubiquitous computing in medical

field• Tiny, non-intrusive computing nodes, integrating

sensors, actuators and radios can be applied to the human body to monitor vital signs.

• Limited bandwidth of GSM (e.g., EDGE), using Bluetooth or WiFi in medical monitoring is more appropriate.

• However, access to Bluetooth and WiFi access points may be intermittent

• The data can propagate hop-by-hop through the peers

Introduction• To examine the feasibility and effectiveness of

– Opportunistic ad hoc networking using Bluetooth – Data muling of medical records from patients to

the Internet medical database.– BlueTorrent

• A P2P file sharing application based on ubiquitous Bluetooth-enabled devices

• The Bluetooth network may be used to alert a nurse that a patient has a medical emergency requiring immediate attention.

Bluetooth Overview• Extended Inquiry Response (EIR)

– Short, urgent message propagation– Supported by a new BT version– No connection delay

Patient Monitoring and Record Management

• Identifying two scenarios and propose two techniques NurseNet and BlueAlert

• NurseNet– Large scale techniques (e.g., WiFi, 3G) are not

adequate or not allowed in some environments.

• BlueAlert– The conventional Bluetooth-based patient

monitoring system is not suitable for emergencies due to Bluetooth connection establishment time (typically, 5-10 seconds).

Scenario I: NurseNet

• NurseNet is a patient data uploading system to the Central Database

• The patients device passes the medical data to a caregiver (say, nurse) device that then transfers the stored data over Bluetooth P2P to the database.

Figure: NurseNet Architecture

Scenario II: BlueAlert• BlueAlert is an emergency alarm protocol

– For urgent messages, Bluetooth devices change their data propagation mode from BlueTorrent to BlueAlert.

• Use a new Bluetooth feature called EIR– EIR travels across a Bluetooth overlay without any

connection delay

Experiment Environments

• Where: Parking lot• Size: ~ 75 X 75 meters• Open Space

• battlefield or disaster area • When: Late Night

• Minimize interference• Three Components

• Patient/Nurse/Doctor• Used Kensington 33348

Bluetooth dongles (v2.0 EDR, Class 2, and Broadcom chipset) for nurse nodes, patient node and BT-AP node.

Experiment Setting• Patient

• Moves inside a designated area of 10x10 meters• Equip with two different body sensors – ECG and Pulse

Oximeter• Continuously transmit data to Gateway through Bluetooth

Connection• Nurse (Three nodes)

– Collects data from patients– Moves around– Exchange data with other nurses

• Doctor– Data collector

Experiment Result

• All nurse nodes contribute to data dissemination• Nurses exchange data, then upload data to AP• As the number of hops increases, data delivery delay

decreases

Simulation Setting: NurseNet

• Simulation Parameters– Area: 100 x 50 meters– Nodes: 50 patients + 5 nurses– Node Speed: 1 meter/seconds (Only nurse moves, Patients are static)– P: 20% (Returns to the main office.)

• At the office, the nurse uploads the data collected so far at one of the BT-APs.

…………

………… Patient

Nurse

Simulation Setting: NurseNet (cont)

• The setting is a Field Hospital. Each patient has body sensors and a Bluetooth-enabled gateway. The sensors keep generating medical data.

• Patient: static (50 nodes)• Nurses: Mobile (5 nurses, average speed: 1m/s)

– Stay with a patient for 5 minutes on average

• Examine two different Bluetooth Overlay mechanisms– P2N(Patient-to-Nurse): Nurse collects data from one

patient– P2N + N2N(Nurses-to-Nurse): Nurses exchange data each

other

Simulation Result: NurseNet

• Collection time– The collection delay is quite high. This is in part due to the assumption that

the nurse does not collect data during the pause.• Relaxing this constraint reduce the collection from 3000 to 100

seconds from annalistic model

• Uploading time– With N2N exchange, data upload rate to the hospital increases (and latency

decreases) with number of nurses and with P.

Collection time Uploading time

Simulation Setting: BlueAlert

• Patients move escorted by nurses• Suddenly, one of patients needs an emergency care from a nurse.• Emergency data is propagated by P2P using Bluetooth EIR• Compare the emergency alarm propagation delay with BT2.0 and BT2.1(EIR)

Patient

Nurse

Emergency

Simulation Result II

• Parameters: – Area: 100 x 100 meters– Nodes: {50, 100, 150 patients} + 5 nurses– Node Speed: 0.5 meter/seconds (Nodes are patients)– Delay measured until one of nurses receives an emergency message from a random patient.

• Analysis– The more number of hops helps the emergency data to reach to one of nurses– EIR: Even though the number of hops increases, propagation delay decreases because EIR does not

take any connection delay among hops; the data is immediately delivered to the next hop.– But 2.0 takes connection setup delays along with each hop and it causes large delay.

Number of nodes Number of nodes

Num

ber o

f Hop

s

Del

ay(s

econ

ds)

Conclusions• Examined Bluetooth based Patient monitoring

system• Established Feasibility and effectiveness of

data muling by Bluetooth Overlays

Future Work• Simulations

– Update the simulation scenario so that the result of our simulation is more close to real world results.

• Experiments– Implement BlueAlert once Bluetooth v2.1 is available and

merge BlueAlert and NurseNet together.– Brain storm on how to utilize EIR other then BlueAlert

• E.g., When NurseNet nodes exchange their file lists. (Reduce connection time)

Thank you

Q&A