Background: Implantable medical devices have increasingly large capacities for storing patient data as a diagnostic aid and to allow patient monitoring. Although these devices can store a significant amount of data, an increased ability for data storage was required for chronic monitoring in recent physiological studies. Method of Approach: Novel high capacity implantable data recorders were designed for use in advanced physiological studies of canines and free-ranging black bears. These hermitically sealed titanium encased recorders were chronically implanted and programmed to record intrabody broadband electrical activity to monitor electrocardiograms and electromyograms, and single-axis acceleration to document relative activities. Results: Changes in cardiac T-wave morphology were characterized in the canines over a 6month period, providing new physiological data for the design of algorithms and filtering schemes that could be employed to avoid inappropriate implantable defibrillator shocks. Unique characteristics of bear hibernation physiology were successfully identified in the black bears, including: heart rate, respiratory rate, gross body movement, and shiver. An unanticipated high rejection rate of these devices occurred in the bears, with five of six being externalized during the overwintering period, including two devices implanted in the peritoneal cavity. Conclusions: High capacity implantable data recorders were designed and utilized for the collection of long-term physiological data in both laboratory and extreme field environments. The devices described were programmable to accommodate the diverse research protocols. Additionally, we have described substantial differences in the response of two species to a common device. Variations in the foreign body response of different mammals must be identified and taken into consideration when choosing tissue-contacting materials in the application of biomedical technology to physiologic research.

2.
Reveal Plus: Information for health professionals. Retrieved March 30, 2005 from http://www.medtronic.com/reveal/revealplus.htmlhttp://www.medtronic.com/reveal/revealplus.html.
3.
Iaizzo
,
P. A.
, 2005, “
Emerging Cardiac Devices and Technologies
,”
The Handbook of Cardiac Anatomy, Physiology and Devices
,
P. A.
Iaizzo
, ed.,
Humana Press
, Chap. 23.
4.
Byrd
,
C. L.
, 2000, “
Management of Implant Complications
,”
Clinical Cardiac Pacing and Defibrillation
,
2nd ed.
,
K. A.
Ellenbogen
,
G. N.
Kay
, and
B. L.
Wilkoff
, eds.,
W.B. Saunders Co.
, Philadelphia, PA, pp.
669
694
.
5.
Byrd
,
C. L.
, and
Wilkoff
,
B. L.
, 2000, “
Techniques and Devices for Extraction of Pacemaker and Implantable Cardioverter-Defibrillator Leads
,”
Clinical Cardiac Pacing and Defibrillation
,
2nd ed.
,
K. A.
Ellenbogen
,
G. N.
Kay
, and
B. L.
Wilkoff
, eds.,
W.B. Saunders Co.
, Philadelphia, PA, pp.
695
709
.
6.
Marshall
,
M. T.
,
et al.
, 2003, “
ICD System T-Wave Changes Impact of Lead and Time
,”
PACE
0147-8389,
26
, p.
1100
.
7.
Moody
,
G. B.
,
Mark
,
R. G.
,
Zoccola
,
A.
, and
Mantero
,
S.
, 1985, “
Derivation of Respiratory Signals from Multi-Lead ECGs
,”
Comput. Cardiol.
0276-6574,
12
, pp.
113
116
.
8.
Hirsch
,
J. A.
, and
Bishop
,
B.
, 1981, “
Respiratory Sinus Arrhythmia in Humans: How Breathing Pattern Modulates Heart Rate
,”
Am. J. Physiol.
0002-9513,
241
, pp.
H620
H629
.
9.
Korte
,
T.
,
Köditz
,
H.
,
Niehaus
,
M.
,
Paul
,
T.
, and
Tebbenjohanns
,
J.
, 2004, “
High Incidence of Appropriate and Inappropriate ICD Therapies in Children and Adolescents With Implantable Cardioverter Defibrillator
,”
Pacing Clin. Electrophysiol.
0147-8389,
27
(
7
), pp.
924
932
.
10.
Echols
,
K. N.
,
Vaughan
,
M. R.
, and
Moll
,
H. D.
, 2004, “
Evaluation of Subcutaneous Implants for Monitoring American Black Bear Cub Survival
,”
Ursus
,
15
, pp.
172
180
.
11.
Harlow
,
H. J.
,
Lohuis
,
T.
,
Beck
,
T. D.
, and
Iaizzo
,
P. A.
, 2001, “
Muscle Strength in Overwintering Bears
,”
Nature (London)
0028-0836,
409
, p.
997
.
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