THL-IMDAG101Implantable Medical Device

AngelMed Guardian ® Implantable Medical Device (IMD) User’s Manual -2- Table of Contents 1 Introduction................................................................ 4 2 Guardian System Overview ...................................... 4 2.1 System Components .................................................... 5 2.2 Indications & Contraindications.................................. 5 3 IMD Device Description ............................................ 6 3.1 Data Acquisition, Characterization, and Storage......... 6 3.2 Vibration Patterns ........................................................ 9 3.3 Wireless Telemetry...................................................... 9 3.4 Radiopaque Identifier ................................................ 10 3.5 Certifications ............................................................. 10 4 Storage, Handling & Resterilization ...................... 11 5 Precautions ............................................................... 12 5.1 General ...................................................................... 12 5.2 Medical Therapy Precautions .................................... 13 5.3 Electromagnetic Interference Precautions ................. 15 6 Implant & Setup Procedures .................................. 16 6.1 Conduct the Pre-Implant Setup Procedure ................ 18 6.2 Implant the Lead........................................................ 20 6.3 Connect the St. Jude Lead to the AngelMed Guardian Lead Adapter ..................................................................... 20 6.4 Connect the Lead Adapter to the IMD ...................... 21 6.5 Implant the IMD and Lead Adapter .......................... 23 6.6 Conduct the Post-Implant Setup Procedure............... 24 6.7 Suture the Pocket Incision Closed ............................. 25 7 Patient Follow-up ..................................................... 26 7.1 Follow-Up Frequency................................................ 26 7.2 Follow-Up Tasks ....................................................... 26 -3- 8 Pre- and Post-Explanting Procedures .................... 27 9 Available Literature................................................. 28 10 Service & Support.................................................... 29 10.1 Service ....................................................................... 29 10.2 Technical Support...................................................... 29 11 Specifications ............................................................ 30 11.1 Physical & Mechanical Specifications ...................... 30 11.2 Environmental Specifications.................................... 31 11.3 Battery Type and Longevity Specifications .............. 31 11.4 Programmable Parameters: Defaults and Ranges..... 32 12 Index.......................................................................... 36 -4- 1 Introduction The AngelMed Guardian ® Implantable Medical Device (IMD) is an implantable programmable device that monitors the patient’s electrogram, vibrates to warn the patient of alarms and alerts, and stores electrogram signals and other data. The IMD is one of five primary components of the AngelMed Guardian System. How supplied – The IMD is supplied in a sterile tray for introduction into the operating field. The tray contains one IMD and a torque wrench. The outer box contains literature. About this manual – This document describes the IMD and provides implantation procedures, as well as an outline of pre- and post-implant setup procedures. For detailed information on pre- and post-implant setup procedures, see the AngelMed Guardian ® Programmer User’s Manual. 2 Guardian System Overview The Guardian System monitors and detects changes in patients’ electrograms, using baseline electrograms from the previous day for comparison. If a change exceeds a pre- specified threshold, the system warns the patient and stores pertinent data for subsequent review. Two levels of warnings are possible: emergency alarms, for significant events that require immediate medical attention, and “see doctor” alerts, for less-significant events that require medical attention as soon as possible (e.g., in 1-2 days.) -5- 2.1 System Components The Guardian System has the following components in addition to the IMD: Lead – a standard bipolar cardiac lead (St. Jude Medical Model 1488T) that is attached to the apex of the right ventricle. Lead Adapter – an adapter that connects the lead to the IMD and houses the antenna. External Device (EXD) – a hand-held telemetry device that warns the patient of alarms and alerts via beeps and a red or yellow flashing LED, and is used to silence alarms and alerts. The EXD is also used for communication between the Programmer and the IMD. Programmer – a customized computer that allows the physician to program IMD parameters and alarm settings for each patient. It also enables the physician to retrieve and review data collected by the IMD. 2.2 Indications & Contraindications The Guardian System is contraindicated when neither the patient nor patient caregiver can take appropriate action for alarms and alerts. Indications and contraindications for the EXD and IMD, individually, are discussed in the AngelMed Guardian ® Clinical Study Protocol. -6- 3 IMD Device Description The fundamental purpose of the IMD is twofold: 1) To detect an “ST shift” – in other words, a shift in the ST deviation of a patient’s electrogram 1 , and 2) If an ST shift occurs, to warn the patient to seek immediate medical help, by vibrating in a recognizable pattern. In addition to ST shift, the IMD detects other types of electrogram changes, such as high heart rate and initial ischemia. Each type of electrogram change is called a “condition.” The physician can specify the type of warning (emergency alarm or “see doctor” alert) that is associated with each condition. See the AngelMed Guardian ® Programmer User’s Manual for detailed information. 3.1 Data Acquisition, Characteriz…

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Angel Medical Systems, Inc. Guardian ® IMD/EXD System for monitoring electrograms (EGMs), 402 MHz – 405 MHz FCC ID: THL- IMDAG101 Photo One – External Implantable Medical Device (IMD) Sealed Product with Measurement / Antenna Leads FCC ID Number: Printed on Sterile Package of the IMD Implant. Once IMD is Implanted, FCC ID not visible. Angel Medical Systems, Inc. Guardian ® IMD/EXD System for monitoring electrograms (EGMs), 402 MHz – 405 MHz FCC ID: THL- IMDAG101 Photo Two – External Implantable Medical Device (IMD) Sealed Product / Backside with out Leads (Note: “Not for human use” labeling is used for verification type tests, not on final product. Angel Medical Systems, Inc. Guardian ® IMD/EXD System for monitoring electrograms (EGMs), 402 MHz – 405 MHz FCC ID: THL- IMDAG101 Photo Three – External Implantable Medical Device (IMD) External Antenna Connection – Close-up Angel Medical Systems, Inc. Guardian ® IMD/EXD System for monitoring electrograms (EGMs), 402 MHz – 405 MHz FCC ID: THL- IMDAG101 Photo Four – External Implantable Medical Device (IMD) Printed Art Work of IMD Implant Sterile Packaging with FCC ID Number ... THL-IMDAG101 Note: The IMD is a Sterile Product, implanted and not visible during operation. AngelMed Guardian ® IMD Model # AG101 Implantable Medical Device (IMD) for detecting and warning a patient of a variety of changes in his or her electrogram. For use ONLY with Angel Medical Systems, Inc. Model LA-001 Lead Adapter and St. Jude Model 1488T Bipolar Cardiac Lead Contents: One IMD, One Torque Wrench The contents (STERILE) of this inner package have been sterilized by ethylene-oxide gas. Sterility cannot be guaranteed if sterile package is damaged or opened. YYYY-MM YYYY-MM XXXXXX -10°C/14° F and +55°C/131°F Caution: Investigational Device. Limited by federal (or United States) law to investigational use. Manufactured for: Angel Medical Systems, Inc. THL-000AG101 1 Sheila Drive Tinton Falls, NJ 07724 USA Phone: 732-212-1888 (USA) (Hi-Tronics Document No.)

Angel Medical Systems, Inc. Guardian ® IMD/EXD System for monitoring electrograms (EGMs), 402 MHz – 405 MHz FCC ID: THL- IMDAG101 Implantable Medical Device (IMD) Printed Art Work of IMD Implant Sterile Packaging with FCC ID Number ... THL-IMDAG101 Note: The IMD is a Sterile Product, implanted and not visible during operation. AngelMed Guardian ® IMD Model # AG101 Implantable Medical Device (IMD) for detecting and warning a patient of a variety of changes in his or her electrogram. For use ONLY with Angel Medical Systems, Inc. Model LA-001 Lead Adapter and St. Jude Model 1488T Bipolar Cardiac Lead Contents: One IMD, One Torque Wrench The contents (STERILE) of this inner package have been sterilized by ethylene-oxide gas. Sterility cannot be guaranteed if sterile package is damaged or opened. YYYY-MM YYYY-MM XXXXXX -10°C/14° F and +55°C/131°F Caution: Investigational Device. Limited by federal (or United States) law to investigational use. Manufactured for: Angel Medical Systems, Inc. THL-000AG101 1 Sheila Drive Tinton Falls, NJ 07724 USA Phone: 732-212-1888 (USA) (Hi-Tronics Document No.)

Angel Medical Systems, Inc. Guardian ® IMD/EXD System for monitoring electrograms (EGMs), 402 MHz – 405 MHz FCC ID: THL- IMDAG101 Photo Four – External Implantable Medical Device (IMD) Printed Art Work of IMD Implant Sterile Packaging with FCC ID Number ... THL-IMDAG101 Note: The IMD is a Sterile Product, implanted and not visible during operation. AngelMed Guardian ® IMD Model # AG101 Implantable Medical Device (IMD) for detecting and warning a patient of a variety of changes in his or her electrogram. For use ONLY with Angel Medical Systems, Inc. Model LA-001 Lead Adapter and St. Jude Model 1488T Bipolar Cardiac Lead Contents: One IMD, One Torque Wrench The contents (STERILE) of this inner package have been sterilized by ethylene-oxide gas. Sterility cannot be guaranteed if sterile package is damaged or opened. YYYY-MM YYYY-MM XXXXXX -10°C/14° F and +55°C/131°F Caution: Investigational Device. Limited by federal (or United States) law to investigational use. Manufactured for: Angel Medical Systems, Inc. THL-IMDAG101 1 Sheila Drive Tinton Falls, NJ 07724 USA Phone: 732-212-1888 (USA) (Hi-Tronics Document No.)

Angel Medical Systems, Inc. Guardian ® IMD/EXD System for monitoring electrograms (EGMs), 402 MHz – 405 MHz FCC ID: THL- IMDAG101 Photo Four – External Implantable Medical Device (IMD) Printed Art Work of IMD Implant Sterile Packaging with FCC ID Number ... THL-IMDAG101 Note: The IMD is a Sterile Product, implanted and not visible during operation. AngelMed Guardian ® IMD Model # AG101 Implantable Medical Device (IMD) for detecting and warning a patient of a variety of changes in his or her electrogram. For use ONLY with Angel Medical Systems, Inc. Model LA-001 Lead Adapter and St. Jude Model 1488T Bipolar Cardiac Lead Contents: One IMD, One Torque Wrench The contents (STERILE) of this inner package have been sterilized by ethylene-oxide gas. Sterility cannot be guaranteed if sterile package is damaged or opened. YYYY-MM YYYY-MM XXXXXX -10°C/14° F and +55°C/131°F Caution: Investigational Device. Limited by federal (or United States) law to investigational use. Manufactured for: Angel Medical Systems, Inc. THL-IMDAG101 1 Sheila Drive Tinton Falls, NJ 07724 USA Phone: 732-212-1888 (USA) (Hi-Tronics Document No.)

Angel Medical Systems, Inc. Guardian ® IMD/EXD System for monitoring electrograms (EGMs), 402 MHz – 405 MHz FCC ID: THL- IMDAG101 Implantable Medical Device (IMD) Printed Art Work of IMD Implant Sterile Packaging with FCC ID Number ... THL-IMDAG101 Note: The IMD is a Sterile Product, implanted and not visible during operation. AngelMed Guardian ® IMD Model # AG101 Implantable Medical Device (IMD) for detecting and warning a patient of a variety of changes in his or her electrogram. For use ONLY with Angel Medical Systems, Inc. Model LA-001 Lead Adapter and St. Jude Model 1488T Bipolar Cardiac Lead Contents: One IMD, One Torque Wrench The contents (STERILE) of this inner package have been sterilized by ethylene-oxide gas. Sterility cannot be guaranteed if sterile package is damaged or opened. YYYY-MM YYYY-MM XXXXXX -10°C/14° F and +55°C/131°F Caution: Investigational Device. Limited by federal (or United States) law to investigational use. Manufactured for: Angel Medical Systems, Inc. THL-000AG101 1 Sheila Drive Tinton Falls, NJ 07724 USA Phone: 732-212-1888 (USA) (Hi-Tronics Document No.)

Angel Medical Systems, Inc. Guardian ® IMD/EXD System for monitoring electrograms (EGMs), 402 MHz – 405 MHz FCC ID: THL- IMDAG101 Implantable Medical Device (IMD) Printed Art Work of IMD Implant Sterile Packaging with FCC ID Number ... THL-IMDAG101 Note: The IMD is a Sterile Product, implanted and not visible during operation. AngelMed Guardian ® IMD Model # AG101 Implantable Medical Device (IMD) for detecting and warning a patient of a variety of changes in his or her electrogram. For use ONLY with Angel Medical Systems, Inc. Model LA-001 Lead Adapter and St. Jude Model 1488T Bipolar Cardiac Lead Contents: One IMD, One Torque Wrench The contents (STERILE) of this inner package have been sterilized by ethylene-oxide gas. Sterility cannot be guaranteed if sterile package is damaged or opened. YYYY-MM YYYY-MM XXXXXX -10°C/14° F and +55°C/131°F Caution: Investigational Device. Limited by federal (or United States) law to investigational use. Manufactured for: Angel Medical Systems, Inc. THL-000AG101 1 Sheila Drive Tinton Falls, NJ 07724 USA Phone: 732-212-1888 (USA) (Hi-Tronics Document No.)

Angel Medical Systems, Inc. Guardian ® IMD/EXD System for monitoring electrograms (EGMs), 402 MHz – 405 MHz FCC ID: THL- IMDAG101 Photo Four – External Implantable Medical Device (IMD) Printed Art Work of IMD Implant Sterile Packaging with FCC ID Number ... THL-IMDAG101 Note: The IMD is a Sterile Product, implanted and not visible during operation. AngelMed Guardian ® IMD Model # AG101 Implantable Medical Device (IMD) for detecting and warning a patient of a variety of changes in his or her electrogram. For use ONLY with Angel Medical Systems, Inc. Model LA-001 Lead Adapter and St. Jude Model 1488T Bipolar Cardiac Lead Contents: One IMD, One Torque Wrench The contents (STERILE) of this inner package have been sterilized by ethylene-oxide gas. Sterility cannot be guaranteed if sterile package is damaged or opened. YYYY-MM YYYY-MM XXXXXX -10°C/14° F and +55°C/131°F Caution: Investigational Device. Limited by federal (or United States) law to investigational use. Manufactured for: Angel Medical Systems, Inc. THL-IMDAG101 1 Sheila Drive Tinton Falls, NJ 07724 USA Phone: 732-212-1888 (USA) (Hi-Tronics Document No.)

AngelMed Guardian ® IMD Model # AG101 Implantable Medical Device (IMD) for detecting and warning a patient of a variety of changes in his or her electrogram. For use ONLY with Angel Medical Systems, Inc. Model LA-001 Lead Adapter and St. Jude Model 1488T Bipolar Cardiac Lead Contents: One IMD, One Torque Wrench The contents (STERILE) of this inner package have been sterilized by ethylene-oxide gas. Sterility cannot be guaranteed if sterile package is damaged or opened. YYYY-MM YYYY-MM XXXXXX -10°C/14° F and +55°C/131°F Caution: Investigational Device. Limited by federal (or United States) law to investigational use. Manufactured for: Angel Medical Systems, Inc. 1 Sheila Drive FCC ID: THL-IMDAG101 Tinton Falls, NJ 07724 USA Phone: 732-212-1888 (USA) ( Document No.)

AngelMed Guardian ® IMD Model # AG101 Implantable Medical Device (IMD) for detecting and warning a patient of a variety of changes in his or her electrogram. For use ONLY with Angel Medical Systems, Inc. Model LA-001 Lead Adapter and St. Jude Model 1488T Bipolar Cardiac Lead Contents: One IMD, One Torque Wrench The contents (STERILE) of this inner package have been sterilized by ethylene-oxide gas. Sterility cannot be guaranteed if sterile package is damaged or opened. YYYY-MM YYYY-MM XXXXXX -10°C/14° F and +55°C/131°F Caution: Investigational Device. Limited by federal (or United States) law to investigational use. Manufactured for: Angel Medical Systems, Inc. 1 Sheila Drive FCC ID: THL-IMDAG101 Tinton Falls, NJ 07724 USA Phone: 732-212-1888 (USA) ( Document No.)

SAR Analysis Report 1 March 10, 2006 Specific Absorption Rate (SAR) Analysis Using Finite Difference Time Domain (FDTD) Computation on behalf of Hi-tronics Designs, Inc. for the Angel Medical Systems Guardian IMD Model AG101 (Implantable Medical Device) The analysis has been performed by Remcom Inc. David C. Carpenter PhD. March 10, 2006 SAR Analysis Report 2 March 10, 2006 Introduction Hi-tronics Designs, Inc. has developed an Implantable Medical Device (IMD) which has the capability of wirelessly transmitting data to/from a patient/physician. The RF communication system utilizes the MICS band (Medical Implant Communications Service). The amount of radiated power transmitted through the human body tissue using this technology may be defined by a measure known as SAR (Specific Absorption Rate). Values of SAR that can be safely used in these applications have been defined by the ANSI/IEEE and are part of the FCC guidelines for medical implant communications. Certification of medical-implant transmitters under the FCC Part 95 Medical Implant Communication Services (MICS) requires a measurement of Finite Difference Time Domain (FDTD) analysis of the SAR associated with the presence of a radio frequency (RF) transmitter. This report details the SAR analysis of the RF transmitter used in the Angelmed Guardian IMD. Summary The commercial software analysis package XFDTD, a finite difference time domain analysis of the electromagnetic fields has been used to calculate the electromagnetic fields produced by the IMD and the resulting SAR (specific absorption rate) in human body tissue. The model used an accurate representation of the IMD and the HiFi Body Mesh available with the XFDTD Software. The results are as follows: Maximum SAR value 674 mW/kg Maximum 1g average SAR value 73 mW/kg Maximum 10g average SAR value 22 mW/kg Average SAR value in torso 18 μW/kg The ANSI C95-1-1992 limit is 1.6 W/kg. In this study, the computed value of the maximum 1g average is 73 mW/kg. The level of computed SAR is 4.5% of the limit stated in the specification. These FDTD results show that the Hi-tronics Designs, IMD can safely be used in its intended application with respect to the energy emitted during normal operation. SAR Analysis Report 3 March 10, 2006 Method of Analysis The software used for the simulation, modeling and analysis was XFDTD v6.3. A 3D CAD model of the IMD was supplied by Hi-tronics Designs, in SAT format. This is the generic format used by the modeling system within XFDTD. The material specification was obtained from Hi-tronics Designs, and the electromagnetic properties of the device were either supplied by Hi-tronics Designs, or obtained from published data. The specific values are provided in Appendix A. Figure 1: 3D CAD model and FDTD Mesh representation of IMD The HiFi Body Mesh supplied with XFDTD was used to model the human tissues and body structure for this analysis. This model included frequency dependent electromagnetic properties of human tissues such that the correct values may be automatically selected to match the frequency of interest. In this case the frequency was 402.5 MHz, which is within the narrow operation frequency of the IMD (FCC MICS Band of 402 MHz to 405 MHz). The tissue material data has been developed over many years and is based on work by Dr.s Smith and Collins of the Hershey Medical Center, Pennsylivania State University. The Human Body mesh was loaded first and the cell size set to 5mm. This matches the resolution of the tissue data within the HiFi Body Model. An initial mesh was generated to include only the Human Body. The IMD CAD model was then imported and positioned in the appropriate location (comparable to a pacemaker) within the Human Body Model. The cell size in the region of the IMD was then reduced to 0.5mm, using the built-in adaptive meshing features in XFDTD. This proved to be adequate to resolve the features of the IMD. From experience, it has become clear that the SAR is highest in the region of the antenna and so the Body Model was then limited to include only the torso to simplify computations and reduce simulation time. SAR Analysis Report 4 March 10, 2006 Figure 2: Torso biological tissue model (full model and selected tissues shown) With IMD in place A single frequency analysis was carried out at 402.5 MHz. XFDTD provides post processing features that allow SAR statistics to be calculated at a single frequency. The body tissue electromagnetic properties data have been determined by using a series of single pole Lorentz equations to fit published measured data to these equations. The equations are in the form of: Where ∞ ε is the infinite frequency permittivity s εis the static frequency permittivity 0 τis the relaxation time (s) ω is the frequency (radians/s) In the MICS region of 402 – 405 MHz, this represents a fairly slowly changing permittivity and conductivity values. Thus it is reasonable to expect similar SAR results over the narrow band of operation of the IMD. The SAR values are calculated from the following equation: z zz y yy x xx E E E SAR ρ σ ρ σ ρ σ 222 2 2 2 ++= where SAR – Specific Absorption Rate (W/kg) zyx,, σ- electrical conductivity (S/m) zyx E ,, - magnitude of electric field (V/m) zyx,, ρ - material density (kg/m 3 ) 2 0 0 ∞ ∞ − 2+ ) − (+ = )( 2 2 ωωδω ω εεεωε j s SAR Analysis Report 5 March 10, 2006 Results of SAR Analysis XFDTD provides results in a tabulated format and as distributed field and SAR values in planes of the model. Figure 3 shows a 3D view of the SAR distribution in the x-y plane where the value of 1 gm average SAR is a maximum. Figure 4 shows a more detailed view of this. The maximum value was computed as 73 mW/kg. Figure 3: 3D view of the SAR distribution at the maximum value SAR Analysis Report 6 March 10, 2006 Figure 4: 2D view of the SAR distribution with and without geometry The statistics table generated by XFDTD v6.3 is given in Figure 5. SAR Analysis Report 7 March 10, 2006 Figure 5: SAR Summ…

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Specific Absorption Rate (SAR) Analysis Using Finite Difference Time Domain (FDTD) Computation on behalf of Hi-tronics Designs, Inc. for the Angel Medical Systems Guardian IMD Model AG101 (Implantable Medical Device) The analysis has been performed by Remcom Inc. David C. Carpenter PhD. March 10, 2006 Introduction Hi-tronics Designs, Inc. (HDI) has developed an Implantable Medical Device (IMD) which has the capability of wirelessly transmitting data to/from a patient/physician. The RF communication system utilizes the MICS band (Medical Implant Communications Service). The amount of radiated power transmitted through the human body tissue using this technology may be defined by a measure known as SAR (Specific Absorption Rate). Values of SAR that can be safely used in these applications have been defined by the ANSI/IEEE and are part of the FCC guidelines for medical implant communications. Certification of medical-implant transmitters under the FCC Part 95 Medical Implant Communication Services (MICS) requires a calculation using Finite Difference Time Domain (FDTD) analysis of the SAR associated with the presence of a radio frequency (RF) transmitter. This report details the SAR analysis of the RF transmitter used in the Angel Medical Systems (AMS) Guardian IMD. Summary The commercial software analysis package XFDTD, a finite difference time domain analysis of the electromagnetic fields has been used to calculate the electromagnetic fields produced by the IMD and the resulting SAR (specific absorption rate) in human body tissue. The model used an accurate representation of the IMD and the HiFi Body Mesh available with the XFDTD Software. The results are as follows: Maximum SAR value 674 mW/kg Maximum 1g average SAR value 73 mW/kg Maximum 10g average SAR value 22 mW/kg Average SAR value in torso 18 μW/kg Table 1: Summary of SAR results from analysis The ANSI C95-1-1992 limit is 1.6 W/kg. In this study, the computed value of the maximum 1g average is 73 mW/kg. The level of computed SAR is 4.5% of the limit stated in the specification. These FDTD results show that the HDI IMD can safely be used in its intended application with respect to the energy emitted during normal operation. Method of Analysis The software used for the simulation, modeling and analysis was XFDTD v6.3. A 3D CAD model of the IMD was supplied by HDI in SAT format. This is the generic format used by the modeling system within XFDTD. The material specification was obtained from HDI and the electromagnetic properties of the device were either supplied by HDI or obtained from published data. The specific values are provided in Appendix A. The CAD model and mesh model used in this analysis are shown in Figure 1. Figures 1c and 1d show the antenna and lead adapter detail of the model. Figure 1d also shows the source voltage model that has been used to excite the antenna. Dimensions of the final mesh model where cross referenced to those described in the IMD users manual and found to be accurate to within 1 cell size (0.5mm). The HiFi Body Mesh supplied with XFDTD was used to model the human tissues and body structure for this analysis. This model included frequency dependent electromagnetic properties of human tissues such that the correct values may be automatically selected to match the frequency of interest. In this case the frequency was 402.5 MHz, which is within the narrow operating frequency of the IMD (FCC MICS Band of 402 MHz to 405 MHz). The Human Body mesh was loaded first and the cell size set to 5mm. This matches the resolution of the tissue data within the HiFi Body Model. An initial mesh was generated to include only the Human Body. The IMD CAD model was then imported and positioned in the appropriate location (comparable to a pacemaker) within the Human Body Model. The cell size in the region of the IMD was then reduced to 0.5mm, using the built-in adaptive meshing features in XFDTD. This proved to be adequate to resolve the features of the IMD. From experience, it has become clear that the SAR is highest in the region of the antenna and so the Body Model was then limited to include only the torso to simplify computations and reduce simulation time. The IMD was placed in the left area chest region, 33 mm below the chest skin (surface), 75 mm to the left of the spine and 160 mm down from the top of the shoulder. Figure 2 illustrates the location. Figure 1a: 3D CAD model of IMD Figure 1b: FDTD 3D Mesh model of IMD Figure 1c: Parts display of IMD Figure 1d: Section through mesh model of IMD Figure 2: Torso biological tissue model (full model and selected tissues shown) With IMD in place A single frequency analysis was carried out at 402.5 MHz, which is expected to be representative of the narrow band of MICS operation (402 MHz – 405 MHz). XFDTD provides post processing features that allow SAR statistics to be calculated at a single frequency. The body tissue electromagnetic properties data have been determined by using a series of single pole Lorentz equations to fit published measured data to these equations. The equations are in the form of: Where ∞ ε is the infinite frequency permittivity s εis the static frequency permittivity 0 τis the relaxation time (s) ω is the frequency (radians/s) In the region of 402.5MHz, this represents a slowly changing permittivity and conductivity. Thus it is reasonable to expect similar SAR results over the narrow band of operation of the IMD. The SAR values are calculated from the following equation: z zz y yy x xx E E E SAR ρ σ ρ σ ρ σ 222 2 2 2 ++= where SAR – Specific Absorption Rate (W/kg) zyx,, σ- electrical conductivity (S/m) zyx E ,, - magnitude of electric field (V/m) zyx,, ρ - material density (kg/m 3 ) Results of SAR Analysis XFDTD provides results in a tabulated format and as distributed field and SAR values in planes of the model. Figure 3 shows a 3D view of the SAR distribution in the x-y plane where the value of 1 gm average SAR is a maximum. Figure 4 shows a more…

Text truncated - open the document above for the full version.

Specific Absorption Rate (SAR) Analysis Using Finite Difference Time Domain (FDTD) Computation on behalf of Hi-tronics Designs, Inc. for the Angel Medical Systems Guardian IMD Model AG101 (Implantable Medical Device) The analysis has been performed by Remcom Inc. David C. Carpenter PhD. March 10, 2006 2 of 21 Introduction Hi-tronics Designs, Inc. (HDI) has developed an Implantable Medical Device (IMD) which has the capability of wirelessly transmitting data to/from a patient/physician. The RF communication system utilizes the MICS band (Medical Implant Communications Service). The amount of radiated power transmitted through the human body tissue using this technology may be defined by a measure known as SAR (Specific Absorption Rate). Values of SAR that can be safely used in these applications have been defined by the ANSI/IEEE and are part of the FCC guidelines for medical implant communications. Certification of medical-implant transmitters under the FCC Part 95 Medical Implant Communication Services (MICS) requires a calculation using Finite Difference Time Domain (FDTD) analysis of the SAR associated with the presence of a radio frequency (RF) transmitter. This report details the SAR analysis of the RF transmitter used in the Angel Medical Systems (AMS) Guardian IMD. Summary The commercial software analysis package XFDTD, a finite difference time domain analysis of the electromagnetic fields has been used to calculate the electromagnetic fields produced by the IMD and the resulting SAR (specific absorption rate) in human body tissue. The model used an accurate representation of the IMD and the HiFi Body Mesh available with the XFDTD Software. The results are as follows: Maximum SAR value 674 mW/kg Maximum 1g aver…

Text truncated - open the document above for the full version.