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Page last updated on Tuesday November 19, 2013

Implantable VHF Systems (IMP)

Historically implants have been used to instrument animals to monitor physiological parameters such as core body temperature, subcutaneous temperature, and heart rate. In early studies there were many concerns over the potential adverse health effects of implant surgery and long term implantation of the system in the body of subject animals. Early reports and observations on several species of mammals, birds, and reptiles implanted for extended time periods indicated that implantation did not seem to adversely affect the behavior of the animal, induce a generalized inflammatory response, or prevent the reproduction of the species that were studied. It was noted that implants were "walled off" soon after implantation. Implants have been successfully removed from animals as long as 7 years after initial implantation surgery. In many instances animals carrying implants have successfully reproduced born and reared young. Although much of this information is anecdotal and has been collected as simply observations during studies specifically addressing other research topics, field reports on the health issues of implanted animals have been extremely favorable. If you choose to use an implant device in a study, Telonics recommends that you review the appropriate literature and consult with the appropriate oversight entities responsible for animal care, health, and treatment at your institution or agency.

Implants though initially used to monitor physiological parameters have more recently been used on numerous species which have a body morphology not suited to wearing external transmitting units. For example, otters simply do not wear collars well and harnessing techniques have been shown to be ineffective and in some cases dangerous to the animal's survival in its environment. Similarly snakes, lizards, and many species of fish are only instrumented using implant technology.

In other applications, the presence of an external device can influence the individual interaction with predators, conspecifics, or even offspring. Therefore in some behavioral studies implant technology is the preferred instrumentation technique because there are no external marks or devices.

Other applications include detection or parturition, the onset of disease processes, or estrous. Radio transmitter implant technology has developed steadily over the years and is today a mature technology for scientific research.

The first step in selecting an implantable transmitting subsystem is determining the appropriate size and weight for the configuration, which includes the transmitting electronics, power supply, and packaging. Often the size and weight of an implant can be greater than with configurations placed on the animal using an external attachment such as a collar. This is especially true with smaller subjects. This is not a recommendation to use the largest implant, but recognition that implants can often be positioned near the center of gravity of the animal, where more weight can be carried and the positioning of the unit is less likely to interfere with normal behavior.

Key Features

Standard Implantable Subsystems


Figure 1. Standard Implantable
Subsystems using Internal Antennas

Click here for
Micro-miniature Implantable Units

Models

Config. Dimensions L x Dia (in, cm) Unit Weight (g) Operational Life
@ 60 BPM
Std. Pow (months)
Operational Life
@ 60 BPM
Low Pow (months)
Transmitter
Electronics
Microprocessor
Control Options
IMP-100 1.6 x 0.7
4.1 x 1.8
11 0.7 1.8 MK8 MS6, MA, MS9, MDC, MS4, MS5
IMP-130 2.1 x 0.75
5.3 x 1.9
19 4.1 10.5 MK8 MS6, MA, MS9, MDC, MS4, MS5
IMP-140 4.2 x 0.75
10.7 x 1.9
40 9.2 23.5 MK8 MS6, MA, MS9, MDC, MS4, MS5
IMP-150 2.1 x 0.9
5.3 x 2.3
21 4.1 10.5 MK8 MS6, MA, MS9, MDC, MS4, MS5
IMP-200 2.4 x 0.9
6.1 x 2.3
25 7.5 19.2 MK8 MS6, MA, MS9, MDC, MS4, MS5
IMP-210 2.9 x 0.9
7.4 x 2.3
38 7.5 19.2 MK8 MS6, MA, MS9, MDC, MS4, MS5
IMP-325 3.7 x 0.9
9.4 x 2.3
42 15 38.3 MK8 MS6, MA, MS9, MDC, MS4, MS5
IMP-400 3.8 x 1.3
9.7 x 3.3
~95 31.8 81.2 MK8 MS6, MA, MS9, MDC, MS4, MS5
IMP-700 6.0 x 1.3
15.2 x 3.3
~158 63.6 162.4 MK8 MS6, MA, MS9, MDC, MS4, MS5

Specifications for Transmitter Electronics

MK8 Transmitter General Specifications Show

VHF Transmitter Sensor Option Descriptions

MK8 Microprocessor Control Sensor Options Show

Legacy Products

The information below is provided for individuals who are still deploying these older systems. Some of the system information or limitations, information on frequency allocation or usage, and/or comments made on "state of the art" may be time sensitive or even outdated. Please contact Telonics if you have any questions about the information provided in this section.

Telonics still supports and refurbishes the following products but no longer sells them new:

IMP-300, IMP-310

Micro-miniature Implantable Subsystems


Figure 3. Micro-miniature
Implantable Units

Click here for Standard Implantable Subsystems

Micro-miniature Implant Subsystems allow the instrumentation of smaller species of animals. The configurations are based on our CHP transmitter. To minimize the size of these configurations very small batteries are used. The smaller battery system limits the operational life of the configuration and also limits the radio frequency (RF) power that can be transmitted by the unit. The CHP electronics are matched to these small battery systems to avoid damaging the batteries yet provide as much range performance as is possible from the configuration. In order to further maximize range of these configurations, they are made with highly flexible external antennas that increase the radiated power. This common configuration is often used in fish and snake applications. Whenever this option is utilized, the implant is internally cast with a polymer and coated in physiological wax to minimize moisture penetration. However, this design is only water resistant - and the penetration of the wax coating by the antenna provides a potential moisture path that ultimately allows, in the long term, penetration of body fluids. The time-frame to moisture penetration is related to the type of external antenna structure selected as well as the flexation and strain placed on the antenna in the body. This technology is best suited to studies 3 to 6 months in duration.

Config Dimensions L x Dia (in, cm) Unit Weight (g) Transmitter Electronics Operational Life @ 60BPM (months) Operational Life @ 35BPM (months) Conventional Sensor Options
IMP-CHP-5P 1.44 x 0.62 x 0.37
3.66 x 1.57 x 0.94
6.8 CHP 8.5 13.6 conventional S2 temp
IMP-CHP-6P 1.0 x 0.62 x 0.37
2.54 x 1.57 x 0.94
3.7 CHP 4.2 6.8 conventional S2 temp
IMP-CHP-7P 0.83 x 0.45 x 0.37
2.11 x 1.14 x 0.94
2.2 CHP 1.6 2.7 conventional S2 temp
IMP-CHP-8P 0.90 x 0.42 x 0.25
2.29 x 1.07 x 0.64
1.2 CHP 0.7 1.1 conventional S2 temp

**Note: The CHP micro miniature transmitter is designed for use with a small battery system. The power output is matched to the power provided by the small battery. Therefore the standard power for an IMP/CHP is much lower than the standards power for a MK8 or MK9 subsystem. This is true of micro miniature transmitter technology in general and throughout the industry.

Specifications for Transmitter Electronics

µCHP Transmitter General Specifications

CHP Conventional Control Options

OPT. S2 Temperature Sensor. Sensor provides pulse rate which varies according to temperature within the transmitting subsystem. User specifies desired pulse rate at anticipated median temperature and approximate range of temperatures to be monitored. Pulse rate increases at higher temperatures and decreases at lower temperatures.

Cautionary Notes for Implantable Subsystems

1. Most Telonics implantable telemetry transmitting subsystems utilize an internal transmitting antenna structure. The structure is contained inside the packaging of the implant. This type of antenna can be tuned to either air or the dielectric of the body. The tuning choice will affect where (in air or in the body) the maximum range performance will be achieved. If the unit is tuned to air, the unit's best performance will be achieved when air surrounds the implant. If the implant antenna is tuned to the dialectic of the body, the best performance from the implant will be achieved when the implant is actually inside the body cavity. Note: When testing, it is necessary to place the implant in the medium in which it will be expected to operate. This is particularly true when trying to obtain more accurate range performance test data.
For extremely large bodied animals (over 100 pounds), it should be noted that the large mass reduces the effective radiated power of the implant, thereby reducing the range performance of the system. When implanting small terrestrial mammals, the implant is often carried only a few inches off the surface of the earth and thus the range is reduced because line-of-sight range is also reduced under these conditions.

2. Cold method sterilization should be utilized when sterilizing units prior to implantation. The physiological wax can melt with hot method sterilization techniques compromising the units' moisture repelling properties. Also note, units should be stored in a cool environment (such as a cooler) during transportation in vehicles, or kept in a cool environment during periods of storage.

Technical Note about Sterilization Methods

Telonics Quarterly - Vol 7 No. 3