Objective

for

System of

Quality of

Measure Life

Team Members

Maja Middleton – Team LeaderKayla Ericson – Communicator

Kristin Riching – BSACKatherine Davis - BWIG

ClientDr. Erwin B. Montgomery M.D.

Department of Neurology

AdvisorProf. Justin Williams

BME Department

Problem Statement

• Design a system or tool to measure the quality of life for a patient suffering from movement disorders.

• The system/device must provide evidence that the quality of life has improved post surgery so that insurance companies will continue to fund deep-brain stimulus rehabilitation.

Quality of Life• Definition: Quality of life is a measure of

the means that people live within their own environments in ways that are best for them

• Applicable Definition: The ultimate goal of deep brain stimulation surgery is to enable people to live quality lives -- lives that are both meaningful and enjoyed, but are also functional mentally, physically and socially.

Three Aspects of Quality of Life

• Mental – Patient’s feelings and attitudes about themselves and their abilities as related to their disease and quality of life – Cognitive assessment (PADLS or MSQOL54)

• Physical – Patient’s ability to perform daily tasks – Bluetooth accelerometer

• Social – Patient’s daily interactions with society and personal relationships– GPS

All three aspects will be measured pre- and post-surgery

Product Design SpecificationsPerformance Requirements

Repeated use, all types of patients, non-invasive, easy to operate

Safety Safe for patient and operator

Accuracy and Reliability Dependable, durable, precise, fulfill companies requirements for objective measure

Life in Service 7 days of operation and battery life, record tri-axial motion, 20 cycles per seconds (accelerometer)

Quantity Five (5) accelerometers Bluetooth enabled, one (1) PDA Bluetooth enabled, one (1) GPS CompactFlash card – one unit can be used for many repeated patients

Target Production Cost Approximately $1600

Ergonomics Light, non-invasive

Size Minimal, fitting watch or PDA (GPS)

Weight Not more than 750 grams (accelerometer)

Materials Hypo-allergenic for all types of patients

Background Material and Research

Movement Disorder Symptoms• Rigidity• Postural Instability• Tremor• Bradykinesia / akinesia

– Slowness– Absence of movement

• Dyskinesia– Abnormal, involuntary

movement– Side effect of drug therapy

Previous Methods

• No previous devices for objective measure of movement disorders found besides written questionnaires and doctor judgment.

• Doctor observation is becoming less accepted as insurance companies lean toward evidence based medicine

Background Material and Research

• Insurance companies only pay for necessary rehabilitation treatments that bring the patient to a normal functioning level for their environment– They continue to fund treatments so

long as progress continues – All progress is marked on a scale that

relates to daily functions of life• Reaching, lifting, standing, walking, dressing, etc…

Deep Brain Stimulation

• For neurologically based movement disorders

• Two electrodes implanted in the brain are fed to a pulse generator implanted in the chest

• The generator delivers high-frequency electrical stimulation that shuts down nerve cells to allow cells to regain self-control

Figure 1: http://www.clevelandclinic.org/neuroscience/techniques/dbs.htm

Physical Design Specifications

•Accelerometers–5 subunits

•One for each wrist (2 total)•One for each ankle (2 total)•One on the trunk as a reference

–Bluetooth enabled•Allows for wireless messaging of data to the central PDA

Figure 2: Top picture - front view; bottom picture – back view

http://www.gvu.gatech.edu/ccg/resources/btacc/index.html

35 mm

35 mmDepth: 5mm

Physical Technical Aspects • All accelerometers need to

communicate together – done via the PDA and Bluetooth technology

• Each signal must be recognized individually by the PDA (X, Y, Z data in ASCII format – number for a character)

• Will sample at 20 Hz (Nyquis’ Theorem)• Battery life (Lithium ion) is about 60

hours (840 mAh – 3.7V)• Has A-D conversion

Central Integration Unit

•Hewlett Packard - Personal Desktop Assistant (PDA)

–Bluetooth enabled PDA–CompactFlash slot–Expansion slot in

PDA for memory capabilities–USB port for easy

PC interfacing

HP iPAQ2215

Figure 3: http://www.circuitcity.com/detail.jsp?c=1&b=g&u=c&qp=0&bookmark=bookmark_0&oid=74016&catoid=-8028&m=0

Central Unit Technical Aspects• PDA

– 64 MB internal RAM– Up to 512 MB of add-on memory– 900 mAh lithium rechargeable battery– Software must be programmed for PDA

to record and store GPS data (every half hour)

– Software must also be programmed to receive, store, and manipulate accelerometer data

– All programming will be done using the software development kit (SDK) from Microsoft

Social Design Specifications

• Laipac Global Positioning System (GPS)

–Tracking GPS compact flash card (to log distance and location)–Low power consumption–Windows compatible

Figure 4: http://www.laipac.com/gps_tf30cf_eng.htm

Social Technical Aspects

• GPS– Record readings every half hour– Accurate to 25 m– 3.3 V– .2 W power consumption– PDA driver is downloadable from the

website

Thank you!

•We just want to extend our thanks to:

•Dr. Montgomery•Prof. Justin Williams•Dr. Jim Abbs•Daryn Belden•Gary Diny, PT

Future Work• The plan for the device is thoroughly

mapped out. The next steps include:– Purchasing the PDA and CompactFlash

card– Writing the software with the SDK for the

GPS– Purchasing the pieces for the

accelerometer – Purchasing the circuit board and

assembling the system– Design and build casing for the

accelerometers– Write software using the SDK for the

accelerometer– Test the integrated system

Overall schematic

Accelerometer

Integrated PDA and GPS

Reference Accelerometer

Upload data to PC

Figure 5: www.circuitcity.com

References

• Davis, William R. Personal Interview. 14 Feb. 2004.• Department of Neurology. (2001). What are Movement

Disorders and How are they Treated? Retrieved March 8, 2004, from Baylor College of Medicine Web site: http://www.bcm.tmc.edu/neurol/struct/park/park6.html

• Diny, Gary. Personal Interview. 27 Feb. 2004.• Hobson, J.P., et al., eds. “The Parkinson’s Disease

Activities of Daily Living Scale: a new simple and brief subjective measure of disability in Parkinson’s disease.” Clinical Rehabilitation 15:1 (2001): 241-246.

• Meyers, Allan R., et al., eds. “Health-Related Quality of Life in Neurology.” Neurology and Public Health 57:1 (2000): 1224-1227.

• Montgomery, Erwin B. Personal Interview. 27 Jan. 2004.• Deep Brain Stimulation surgery. Retrieved April 25, 2004.

http://www.clevelandclinic.org/neuroscience/techniques/dbs.htm

• Deep Brain Stimulation Surgery. Retrieved April 25, 2004. www.wemove.org