SECURITIES AND EXCHANGE COMMISSION
                              WASHINGTON, DC 20549
                   ------------------------------------------
                                    FORM 10-K

  (mark one)
  [ X ] Annual Report Pursuant to Section 13 or 15(d) of the Securities
        Exchange Act of 1934 for the fiscal year ended January 3, 1998
  [   ] Transition Report Pursuant to Section 13 or 15(d) of the Securities
        Exchange Act of 1934

                          Commission file number 1-9567

                                 THERMEDICS INC.
             (Exact name of Registrant as specified in its charter)
  Massachusetts                                                     04-2788806
  (State or other jurisdiction of                             (I.R.S. Employer
  incorporation or organization)                           Identification No.)

  470 Wildwood Street, P.O. Box 2999
  Woburn, Massachusetts                                             01888-1799
  (Address of principal executive offices)                          (Zip Code)
       Registrant's telephone number, including area code: (617) 622-1000

           Securities registered pursuant to Section 12(b) of the Act:

        Title of each class        Name of each exchange on which registered
    ----------------------------   -----------------------------------------
    Common Stock, $.10 par value            American Stock Exchange

          Securities registered pursuant to Section 12 (g) of the Act:
                                      None
  Indicate by check mark whether the Registrant (1) has filed all reports
  required to be filed by Section 13 or 15(d) of the Securities Exchange Act
  of 1934 during the preceding 12 months, and (2) has been subject to the
  filing requirements for at least the past 90 days. Yes [ X ] No [   ]

  Indicate by check mark if disclosure of delinquent filers pursuant to Item
  405 of Regulation S-K is not contained herein, and will not be contained, to
  the best of the Registrant's knowledge, in definitive proxy or information
  statements incorporated by reference into Part III of this Form 10-K or any
  amendment to this Form 10-K. [   ]

  The aggregate market value of the voting stock held by nonaffiliates of the
  Registrant as of January 30, 1998, was approximately $234,966,000.

  As of January 30, 1998, the Registrant had 36,725,953 shares of common stock
  outstanding.
                       DOCUMENTS INCORPORATED BY REFERENCE

  Portions of the Registrant's 1997 Annual Report to Shareholders for the year
  ended January 3, 1998, are incorporated by reference into Parts I and II.

  Portions of the Registrant's definitive Proxy Statement for the Annual
  Meeting of Shareholders to be held on June 1, 1998, are incorporated by
  reference into Part III.
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                                     PART I

    Item 1. Business

    (a) General Development of Business

        The businesses of Thermedics Inc. (the Company or the Registrant) are
    divided into two segments: Instruments and Other Equipment, and
    Biomedical Products. The Company's Instruments and Other Equipment
    segment includes Thermo Sentron Inc., which designs, develops,
    manufactures, and sells high-speed precision-weighing and inspection
    equipment for industrial production and packaging lines. Also part of the
    Instruments and Other Equipment segment is the Company's Orion laboratory
    products division, which manufactures electrode-based
    chemical-measurement products that determine the quality of a wide
    variety of substances by measuring components, such as pH, ion, dissolved
    oxygen, and conductivity levels and are used in the agricultural,
    biomedical research, food-processing, pharmaceutical, and many other
    industries. Through the Company's Thermedics Detection Inc. subsidiary,
    the Instruments and Other Equipment segment also develops, manufactures,
    and markets high-speed, on-line detection instruments used in a variety
    of industrial process applications, security applications, and laboratory
    analysis. In March and November 1996, Thermedics Detection issued shares
    of its common stock in private placements for net proceeds of $7.0
    million, and in March 1997, Thermedics Detection completed the sale of
    shares of common stock in its initial public offering for net proceeds of
    $28.1 million. The Instruments and Other Equipment segment, through the
    Company's Thermo Voltek Corp. subsidiary, also designs, manufactures, and
    markets electronic-test instruments, and a range of products related to
    power amplification, conversion, and quality.

        As part of its Biomedical Products segment, the Company's Thermo
    Cardiosystems Inc. subsidiary has developed two implantable left
    ventricular-assist systems (LVAS): a pneumatic, or air-driven, system and
    an electric version. Thermo Cardiosystems' Nimbus Medical Inc.
    subsidiary, the business of which was acquired in December 1996, has been
    involved in artificial heart technology for more than 20 years and has
    carried out research in two primary fields: ventricular-assist devices
    and total artificial hearts. Nimbus was instrumental in developing the
    basic technology for high-speed rotary blood pumps. On May 2, 1997,
    Thermo Cardiosystems acquired International Technidyne Corporation from
    Thermo Electron Corporation in exchange for the right to receive
    3,355,705 shares of Thermo Cardiosystems' common stock. International
    Technidyne is a leading manufacturer of near-patient, whole-blood
    coagulation testing equipment and related disposables and also
    manufacturers premium-quality, single-use skin-incision devices. The
    3,355,705 shares of Thermo Cardiosystems' common stock issuable in the
    merger will not be issued until the listing of such shares for trading
    upon the American Stock Exchange has been approved by Thermo
    Cardiosystems' shareholders. Because the Company is the majority
    shareholder and intends to vote its shares in favor of such listing, the
    approval is assured. In addition, as part of its Biomedical Products
    segment, the Company also develops, manufactures, and markets enteral
    nutrition-delivery systems and a line of medical-grade polymers used in
    medical disposables and nonmedical, industrial applications, including
    safety glass and automotive coatings.

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        The Company was incorporated in 1983 under the laws of Massachusetts
    as a wholly owned subsidiary of Thermo Electron. Prior to that time, the
    business of the Company was conducted by the R & D/New Business Center of
    Thermo Electron. As of January 3, 1998, Thermo Electron owned 21,141,471
    shares of the Company's common stock, representing 58% of such stock
    outstanding. Thermo Electron provides analytical and monitoring
    instruments; biomedical products including heart-assist devices,
    respiratory-care equipment, and mammography systems; paper recycling and
    papermaking equipment; alternative-energy systems; industrial process
    equipment; and other specialized products. Thermo Electron also provides
    industrial outsourcing, particularly in environmental-liability
    management, laboratory analysis, and metallurgical processing, and
    conducts advanced-technology research and development.

        Thermo Electron intends, for the foreseeable future, to maintain at
    least 50% ownership of the Company. This may require Thermo Electron to
    purchase additional shares of the Company's common stock (or debentures
    convertible into common stock) from time to time, as the number of the
    Company's outstanding shares increases. These or any other purchases may
    be made either in the open market or directly from the Company. See Notes
    4 and 7 to Consolidated Financial Statements in the Company's 1997*
    Annual Report to Shareholders for a description of the Company's
    outstanding stock options and convertible debentures. During 1997, Thermo
    Electron purchased 852,264 shares of the Company's common stock in the
    open market for $17.4 million. Additionally, during 1997, Thermo Electron
    purchased in the open market 50,400 shares, 186,500 shares, and 426,900
    shares of the common stock of Thermo Cardiosystems, Thermo Voltek, and
    Thermo Sentron, respectively, for $1.4 million, $1.8 million, and $4.8
    million, respectively.

        On February 5, 1998, the Company's Board of Directors voted to issue
    4,880,533 shares of its common stock to Thermo Electron in exchange for
    100% of the stock of TMO TCA Holdings Inc., which is the beneficial owner
    of 3,355,705 shares of Thermo Cardiosystems' common stock. The issuance
    of the 3,355,705 shares of Thermo Cardiosystems common stock is subject
    to the approval by Thermo Cardiosystems' shareholders for the acquisition
    of International Technidyne from Thermo Electron. The Company's issuance
    of the 4,880,533 shares of its common stock to Thermo Electron is subject
    to approval by the Company's shareholders. However, because Thermo
    Electron is the majority shareholder and intends to vote its shares in
    favor of the transaction, approval is assured. The shares of common stock
    will be exchanged at their respective fair market values as of February
    5, 1998.

    Forward-looking Statements

        Forward-looking statements, within the meaning of Section 21E of the
    Securities and Exchange Act of 1934, are made throughout this Annual
    Report on Form 10-K. For this purpose, any statements contained herein
    that are not statements of historical fact may be deemed to be

    * References to 1997, 1996, and 1995 herein are for the fiscal years
      ended January 3, 1998, December 28, 1996, and December 30, 1995,
      respectively.

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    forward-looking statements. Without limiting the foregoing, the words,
    "believes," "anticipates," "plans," "expects," "seeks," "estimates," and
    similar expressions are intended to identify forward-looking statements.
    There are a number of important factors that could cause the results of
    the Company to differ materially from those indicated by such
    forward-looking statements, including those detailed under the heading
    "Forward-looking Statements" in the Registrant's 1997 Annual Report to
    Shareholders, which statements are incorporated herein by reference.

    (b) Financial Information About Industry Segments

        Financial information concerning the Company's industry segments is
    summarized in Note 14 to Consolidated Financial Statements in the
    Registrant's 1997 Annual Report to Shareholders, which information is
    incorporated herein by reference.

    (c) Description of Business

    Instruments and Other Equipment

        Precision-weighing and Inspection Equipment. Thermo Sentron serves
    two principal markets: packaged goods and bulk materials. Thermo
    Sentron's products for the packaged-goods market include a broad range of
    checkweighing equipment and metal detectors that can be integrated at
    various stages in production lines for process control and quality
    assurance. These products are sold primarily to customers in the
    food-processing, pharmaceutical, mail-order, and other industries.
    Products in Thermo Sentron's bulk-material line include conveyor belt
    scales, solid level-measurement and conveyor-monitoring systems, sampling
    systems, and small-capacity feeders. These products are sold primarily to
    customers in the mining and material-processing industries, as well as
    electric utilities, chemical, and other manufacturing companies. In
    February 1997, the Company acquired the business of RCC Industrial
    Electronics Pty. Limited (RCCI), an Australia-based manufacturer of
    in-motion checkweighers for the food and pharmaceutical industries. In
    July 1997, the Company acquired Westerland Engineering Ltd., a United
    Kingdom-based manufacturer of process-weighing and control equipment.

        During 1997, 1996, and 1995, the Company derived revenues of $78.7
    million, $70.0 million, and $67.5 million, respectively, from its
    precision-weighing and inspection equipment.

        Laboratory Products. To expand its product quality assurance
    offerings, the Company acquired Orion in December 1995. Orion
    manufactures electrode-based chemical-measurement products that determine
    the quality of a wide variety of substances by measuring components, such
    as pH, ion, dissolved oxygen, and conductivity levels. Orion's products
    are used in the agricultural, biomedical research, food-processing,
    pharmaceutical, and many other industries. Pure water monitors, also
    marketed under the Orion name, use ion-selective technology to monitor
    parameters required for the control of high-purity water systems in power
    generation and other industrial applications. Other products include Cahn
    microweighing and moisture balances and Lear/Fischer filtration/moisture

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    analysis products, all marketed under the Orion brand name. Orion also
    markets consumable products for its earlier instruments line.

        During 1997 and 1996, the Company derived revenues from laboratory
    products of approximately $53.1 million and $50.9 million, respectively.

        Process Detection Instruments. Thermedics Detection designs,
    manufactures, and markets high-speed on-line trace (parts-per-trillion)
    measurement, detection, and rejection equipment that uses particle- and
    vapor-detection and other technologies for product quality and
    productivity applications. The Alexus(R) system detects trace amounts of
    constituents that affect product quality in refillable plastic soft
    drink, water and other beverage containers. In 1996, the Company began
    selling its high-speed X-ray imaging system, marketed under the brand
    name InScan(TM), which uses high-speed X-ray imaging technology to
    determine accurate fill volume, net volume, and package integrity of
    containers for the beverage, food, and other industries. In 1996, the
    Company also introduced a high-speed gas chromatography instrument,
    marketed under the brand name Flash-GC(TM), which analyzes chemical
    samples at speeds 20 to 50 times faster than conventional gas
    chromatography. Thermedics Detection's Moisture Systems division,
    acquired in 1996, designs, manufactures, and markets equipment that uses
    near-infrared (NIR) spectroscopy to measure moisture and other product
    constituents, including fats, proteins, oils, flavorings, solvents,
    adhesives, and coatings, in a variety of manufacturing processes. These
    systems are used across the food, pharmaceutical, chemical,
    petrochemical, tobacco, forest products, paper converting, plastics,
    textiles, corrugating, and other industries.

        During 1997, 1996, and 1995, the Company derived revenues of
    approximately $37.8 million, $34.0 million, and $18.5 million,
    respectively, from its process detection instrument business. 

        Security Instruments. Also through Thermedics Detection, the Company
    designs, manufactures, and markets security instruments that use trace
    particle- and vapor-detection techniques for forensics, search and
    screening applications under the direction of police, border police,
    transportation authorities, and carriers. The Company's principal
    security instrument is the EGIS(R) system, a highly sensitive particle-
    and vapor-detection system for screening people, baggage, packages,
    freight, and electronic equipment such as personal computers for the
    presence of a wide range of explosives, including plastic explosives that
    have proven difficult to detect using conventional methods. The EGIS
    system is designed for stand-alone use in the detection of explosives in
    carry-on items and on personnel, and can be used in conjunction with
    enhanced X-ray and other advanced imaging systems to provide a
    comprehensive explosives-detection system for checked luggage. Initially
    developed with internal funds and contract funding from the Federal
    Aviation Administration (FAA) and the U.S. Department of State, more than
    200 EGIS units have been deployed to date. The EGIS system is currently
    operational in 24 countries and is in use in carry-on and checked-luggage
    screening at more than 45 international airports. EGIS is also used in
    government buildings and embassies, and at border crossings and other

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    locations where there is a high degree of concern for security. The EGIS
    system has assisted in identifying explosives used in terrorist bombings,
    including those in the Federal Building in Oklahoma City and the World
    Trade Center in New York, as well as in Israel, Buenos Aires, and the
    United Kingdom. In March 1996, the Company supplied the U.S. government
    with eight EGIS systems to provide counter-terrorism support in Israel.
    Most recently, the Bureau of Alcohol, Tobacco and Firearms and the
    Federal Bureau of Investigation used EGIS systems in their attempt to
    identify the cause of the crash of TWA Flight 800.

        In September 1996, the Company entered into a development contract
    with the FAA to develop EGIS II, a lower-cost EGIS unit for use in more
    portable applications such as remote security checkpoints and
    counter-terrorism activities. In November 1996, the Company introduced
    its new SecurScan, a prototype of a walk-through trace detector designed
    to screen 10 passengers per minute, and introduced its Rampart system, a
    lower-cost unit for airport applications, in 1997. In addition, in 1997,
    the Company entered into a development contract with the British Ministry
    of Defense to develop an explosives-detection system that is even more
    sensitive than the EGIS system.

        Test Instruments and Power Products. Through its Thermo Voltek
    subsidiary, the Company designs, manufactures, and markets
    electronic-test instruments and a range of products related to power
    amplification, conversion, and quality. The Company's test instruments
    simulate pulsed electromagnetic interference, radio frequency
    interference, and changes in AC voltage, to allow manufacturers of
    electronic systems and integrated circuits to test for electromagnetic
    compatibility (EMC). These products are used in the product-development,
    design-verification, and quality-assurance stages, enabling customers to
    optimize performance, reliability, and safety in the final design, and to
    meet industry standards and regulatory requirements, including a European
    Union directive that took effect in January 1996. The Company's power
    products include radio frequency (RF) and microwave power amplifiers,
    power-conversion equipment, and high-voltage and application-specific
    power supplies. These power products are used in communications,
    broadcast, research, and medical imaging applications.  During 1997, the
    Company experienced lower demand for its EMC test products, due to the
    declining influence of IEC 801, the European Union directive on
    electromagnetic compatibility that took effect January 1, 1996, and, to a
    lesser extent, a decline in the component-reliability market for
    electrostatic discharge test equipment that resulted from a slowdown in
    capital expenditures by the semiconductor industry. Due in part to these
    developments, during 1997 the Company implemented certain operational,
    organizational, and personnel changes.

        During 1997, 1996, and 1995, the Company derived revenues of $44.6
    million, $48.5 million, and $36.3 million, respectively, from its test
    instruments and power products.

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    Biomedical Products

        Left Ventricular-assist Systems. The Company, through its Thermo
    Cardiosystems subsidiary, has developed two versions of its LVAS: an
    implantable pneumatic, or air-driven, system that can be controlled by
    either a bedside or portable console; and an electric system that
    features an internal electric motor powered by an external battery pack
    worn by the patient. Both of the Company's systems employ the Company's
    HeartMate(R) blood pump, and are designed for long-term use. This pump is
    implanted just below the diaphragm in a position that minimizes
    interference with normal circulation and other bodily functions. An inlet
    tube is inserted into the apex of the left ventricle to drain blood into
    the pump chamber. Blood is then forced out of the pump through an animal
    tissue valve and back into the aorta. The HeartMate blood pump works with
    the biological control mechanism of the natural heart to increase pumping
    capability when required for activities such as climbing stairs. The
    Company's LVAS devices are at various stages of regulatory approval.

        Air-driven LVAS. In October 1994, the FDA approved the air-driven
    system as a bridge to transplant for patients awaiting heart
    transplantation. This approval allows the Company to sell the air-driven
    LVAS to any of the nearly 900 cardiac surgery centers in the United
    States. In April 1994, the Company received the CE Mark for commercial
    sale of the air-driven LVAS in all European Community countries. In the
    air-driven LVAS, the HeartMate blood pump is coupled to an external
    console connected to the body by a tube. The Company has also developed
    the HeartPak(TM), a lightweight portable console that can be carried over
    the shoulder. The portable console received the CE Mark for commercial
    sale in European Community countries in February 1995. In July 1995, the
    FDA approved the beginning of Phase I clinical trials of the HeartPak
    portable pneumatic driver. The HeartPak is currently in Phase I clinical
    trials in the U.S. Phase I of the study is evaluating the safety of the
    system in the hospital; Phase II will evaluate the system in the home
    environment.

        Electric LVAS. The Company has also developed an electric LVAS that
    uses the HeartMate blood pump driven by an internal electric motor
    mounted in the blood pump housing. The system is connected to its
    external battery pack by wires that exit the body. Since the power source
    and control elements are worn on a battery belt, the system allows the
    patient complete mobility. In August 1995, the electric LVAS was awarded
    the CE Mark, allowing commercial sale of this system in all European
    Community countries. The electric system is used as a bridge to
    transplant in the United States and Europe, and is also implanted as an
    alternative to heart transplant in Europe. The electric LVAS may not be
    sold commercially in the United States until it has received approval
    from the FDA. The electric LVAS is currently being used in the United
    States in clinical trials for patients awaiting heart transplants. In
    June 1997, the Company submitted a PMA supplemental application to
    receive FDA approval of the electric LVAS as a bridge to transplant. This
    application is currently under review; however, no assurance can be given
    that the FDA will review this application on a timely basis or will grant
    approval once it completes its review.

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        During 1997, 1996, and 1995, the Company derived revenues of $25.0
    million, $30.0 million, and $20.6 million, respectively, from its LVAS.

        Blood-testing Equipment and Skin-incision Devices. The Company's
    International Technidyne subsidiary manufacturers and supplies
    whole-blood coagulation testing equipment and related disposables, as
    well as skin-incision devices. International Technidyne's product lines
    offer whole-blood coagulation systems for bedside anticoagulation
    management, coagulation screening, and transfusion management. Each
    analyzes small blood samples, then processes and quickly displays
    comprehensive patient homeostasis information. Blood management of this
    type is essential as the number of invasive medical procedures, such as
    cardiopulmonary bypass surgery and angioplasty, increase. The ProTime(R)
    Microcoagulation System is designed to allow long-term oral anticoagulant
    patient self-testing. International Technidyne also manufactures a family
    of single-use skin-incision devices for drawing blood from adults,
    children, and infants. 

        Medical-grade Polymers and Enteral Nutrition-delivery Systems. The
    Company's research relating principally to the development of its LVAS
    has resulted in the development of proprietary medical-grade plastics
    marketed under the names Tecoflex(R) and Tecothane(R). Tecoflex and
    Tecothane are thermoplastic polyurethanes used in medical disposables and
    industrial products. The Company sells Tecoflex and Tecothane in bulk
    form for fabrication by the customer, and the Company also extrudes
    precision tubing to customer specifications.

        In 1993, the Company introduced Scent Seal fragrance samplers, which
    were developed from the Company's polymer technology. Scent Seal
    fragrance samplers are used to hermetically seal a fragrance rendition in
    perfume advertisements for magazines, and are an alternative to commonly
    used fragrance strips. In June 1995, Thermedics entered into an agreement
    granting Arcade, Inc., the leading manufacturer of scent-sampling
    products, an exclusive, worldwide license to manufacture and distribute
    the Company's fragrance samplers under Thermedics' patents and know-how.
    Under the license agreement, Arcade pays royalties to Thermedics on
    licensed fragrance samplers sold by Arcade, and Thermedics continues to
    provide the polymer gels needed to produce the fragrance samplers. 

        The Company's Corpak Inc. subsidiary designs, manufactures, and
    markets enteral feeding systems that introduce special nutritional
    solutions into the stomach or the small intestine through tubes entering
    the nose or stomach. Enteral therapy is used for patients who are unable
    to feed themselves but who do not require parenteral (intravenous)
    feeding. Corpak's products include bags for nutritional fluids, delivery
    pumps, associated pump sets that hook up to the pumps, and feeding tubes.
    In addition, Corpak markets a range of enteral feeding supplements.

        (ii) and (xi) New Products; Research and Development

        The Company maintains research and development capability to support
    its existing products and to develop new products. A number of programs
    are underway, funded by the Company solely or jointly with an outside

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    source. These programs include development of new products to perform
    substantially all or part of the pumping function of the left ventricle
    of the natural heart, process detection and security instruments,
    electronic test instruments, and high voltage power supply products. The
    Company also develops new grades of polymers to meet specific customer
    requirements for industrial and medical applications.

        During 1997, 1996, and 1995, the Company expended $24,270,000,
    $21,363,000, and $14,874,000, respectively, on internally sponsored
    research and development programs, and $2,890,000, $1,410,000, and
    $3,125,000, respectively, on research and development programs sponsored
    by others. As of January 3, 1998, 213 professional employees were engaged
    full-time in research and development activities.

        (iii) Raw Materials

        Certain raw materials used in the manufacture of the Company's LVAS
    are available from only one or two suppliers. The Company is making
    efforts to minimize the risks associated with sole sources and ensure
    long-term availability, including qualifying alternative materials and
    components or developing alternative sources for the materials and
    components supplied by a single source. Although the Company believes
    that it has adequate supplies of materials and components to meet demand
    for the LVAS for the foreseeable future, no assurance can be given that
    the Company will not experience shortages of certain materials or
    components in the future that could delay shipments of the LVAS.

        The cost to the Company to evaluate and test alternative materials
    and components and the time necessary to obtain FDA approval for these
    materials and components are inherently difficult to determine because
    both time and cost are dependent on at least two factors: the similarity
    of the alternative material or component to the original material or
    component, and the amount of third-party testing that may have already
    been completed on alternative materials or components. There can be no
    assurance that the substitution of alternative materials or components
    will not cause delays in the Company's LVAS development program or
    adversely affect the Company's ability to manufacture and ship LVAS to
    meet demand.

        (iv) Patents, Licenses, and Trademarks

        The Company considers its intellectual property important in the
    operation and growth of its business, and its policy is to protect this
    property through patents, license and confidentiality agreements,
    trademarks, and trade secret protection. The Company applies for and
    maintains patents in the U.S. and in foreign countries, particularly in
    the areas of biomedical materials, medical products, and analytical
    instruments. Although some of these patent rights may provide the Company
    with a competitive advantage, the Company primarily relies on its
    know-how and trade secrets. In addition, there can be no assurance that
    third parties will not assert claims against the Company that the Company
    infringes the intellectual property rights of such parties. The Company
    could incur substantial costs and diversion of management resources with

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    respect to the defense of any such claims, which could have a material
    adverse effect on the Company's business, financial condition, and
    results of operations. Furthermore, parties making such claims could
    secure a judgment awarding substantial damages, as well as injunctive or
    other equitable relief, which could effectively block the Company's
    ability to make, use, sell, distribute, or market its products and
    services in the U.S. or abroad. In the event that a claim relating to
    intellectual property is asserted against the Company, the Company may
    seek licenses to such intellectual property. There can be no assurance,
    however, that such licenses could be obtained on commercially reasonable
    terms, if at all. The failure to obtain the necessary licenses or other
    rights could preclude the sale, manufacture, or distribution of the
    Company's products and, therefore, could have a material adverse effect
    on the Company's business, financial condition, and results of
    operations. Thermo Cardiosystems has received correspondence from a third
    party alleging that the textured surface of the LVAS housing infringes
    certain patent rights of such third party. The third party has offered
    Thermo Cardiosystems a license, which Thermo Cardiosystems has elected
    not to accept. Although Thermo Cardiosystems believes that it has
    meritorious defenses to the claims of the third party, due to the
    inherent uncertainty of litigation, no assurance can be made that Thermo
    Cardiosystems would be successful if any litigation were to begin.

        The Company also has certain licenses to the technology resulting
    from its customer-sponsored development of the Alexus system. The
    Company's patents and agreements have varying lives ranging from one year
    to approximately twenty years, and the Company does not believe that the
    expiration or termination of any one of these patents or agreements would
    materially affect the Company's business.

        (v) Seasonal Influences

        There are no significant seasonal influences on the Company's sales
    of its products.

        (vi) Working Capital Requirements

        There are no special inventory requirements or credit terms extended
    to customers that would have a material adverse effect on the Company's
    working capital.

        (vii) Dependency on a Single Customer

        No customer represented 10% or more of the Company's total revenues
    in 1997, 1996, and 1995.


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        (viii) Backlog

        The Company's backlog of firm orders at year-end 1997 and 1996 was as
    follows:

    (In thousands)                                           1997      1996
    -----------------------------------------------------------------------
    Instruments and Other Equipment                       $32,735   $39,000
    Biomedical Products                                     3,847     2,729
                                                          -------   -------
                                                          $36,582   $41,729
                                                          =======   =======

        Certain of these orders are cancellable by the customer upon payment
    of a cancellation charge. The Company anticipates that substantially all
    of the backlog at the end of 1997 will be shipped or completed during
    1998. The Company does not believe the size of its backlog is necessarily
    indicative of intermediate or long-term trends in its business.

        (ix) Government Contracts

        Not applicable.

        (x) Competition

    Instruments and Other Equipment

        Precision-weighing and Inspection Equipment. The Company's Thermo
    Sentron subsidiary encounters and expects to continue to encounter
    intense competition in the sale of its products. Thermo Sentron's
    principal competitors in the packaged-goods market are Ishida Scales Mfg.
    Co., Ltd. and Mettler-Toledo AG. In the more fragmented bulk-materials
    market, Thermo Sentron competes on a worldwide basis primarily with Carl
    Schenck AG and Milltronics Corporation. Thermo Sentron believes that the
    principal competitive pressures affecting the market for
    precision-weighing and inspection equipment include customer service and
    support, quality and reliability, price, accuracy, ease of use,
    distribution channels, technical features, compatibility with customers'
    manufacturing processes, and regulatory approvals.

        Laboratory Products. The Company's Orion division competes with
    several international companies. The Company competes on the basis of
    performance, service, technology, and price.

        Process Detection Instruments. The Company's process detection
    instruments compete with systems manufactured by numerous companies. The
    Company believes that these companies are generally focused on particular
    niches in the process detection systems market, only in some of which
    does the Company compete. Competition in the markets for each of the
    Company's process detection systems is based primarily on performance,
    durability, service and, to a lesser extent, price. The Company believes
    that its systems' performance and speed, as well as the Company's
    reputation for developing superior new technologies and for the
    innovative application of existing technologies to a variety of

                                       11PAGE
<PAGE>
    high-speed production environments and product quality-assurance
    problems, are competitive advantages.

        Security Instruments. In the explosives-detection market, the Company
    competes with a small number of companies, including other makers of
    chemical trace-detection instruments, and, to a lesser degree, makers of
    enhanced X-ray detectors. Competition in this market is based primarily
    on performance, including speed, accuracy, and the range of explosives
    that can be detected; ease of use; service; and price. The Company's
    principal competitor in the trace detection market is Barringer
    Technologies Inc., a Canadian firm that has placed several trace
    detectors in airport applications. 

        Test Instruments and Power Products. The Company is a leading
    supplier of EMC testing equipment. There are numerous companies worldwide
    that independently manufacture and market pulsed EMC test equipment for
    electronic products, and several more that independently manufacture and
    market component-reliability test equipment. In the market for RF power
    amplifiers and programmable power amplifiers, the Company competes with
    several companies worldwide.  In the market for high-voltage power supply
    systems of the general type manufactured and marketed by the Company, the
    Company competes with numerous companies for both contract and commercial
    sales. The Company competes in these markets primarily on the basis of
    performance, technical expertise, reputation, and price. Substantially
    all of the Company's contract and commercial revenues are subject to
    intense competitive bidding. Some of the Company's competitors have
    substantially greater financial resources than those of the Company.

    Biomedical Products

        Left Ventricular-assist Systems. The Company is aware of one other
    company that has submitted a PMA application with the FDA for an
    implantable LVAS. The Company is unaware whether this PMA application has
    been accepted for filing by the FDA. Also, the Company is aware of one
    other company that has received approval by the FDA Advisory Panel on
    Circulatory System Devices and subsequent commercial approval for its
    cardiac-assist device. This is an external device, positioned on the
    outside of the patient's chest, and is intended for short-term use in the
    hospital environment. In addition, the Company is aware that a total
    artificial heart is currently undergoing clinical trials. The requirement
    of obtaining FDA approval for commercial sale of an LVAS in the United
    States is a significant barrier to entry into the United States market
    for these devices. There can be no assurance, however, that FDA
    regulations will not change in the future, reducing the time and testing
    required for others to obtain FDA approval for commercial sale. In
    addition, other research groups and companies, some that have
    significantly greater resources than those of the Company, are developing
    cardiac systems using alternative technologies or concepts, one or more
    of which might prove functionally equivalent to, or more suitable than,
    the Company's systems. Among products that have been approved for
    commercial sale, the Company competes primarily on the basis of
    performance, service capability, and price. Competition in the market for
    medical devices is also significantly affected by the reimbursement

                                       12PAGE
<PAGE>
    policies of government and private insurers. Any product for which
    reimbursement is not available from such third-party payers will be at a
    significant competitive disadvantage.

        Blood-testing Equipment and Skin-incision Devices. International
    Technidyne's principal competitor in the market for coagulation
    monitoring instruments such as HEMOCHRON is the HemoTec division of
    Medtronic, which manufactures a whole-blood ACT instrument as well as the
    Hepcon Hemostatic Monitoring System. International Technidyne also
    competes with CDI, which is attempting to compete with HEMOCHRON.
    Boehringer Mannheim Corporation has developed a patient blood coagulation
    self-testing device similar to the ProTime, which is marketed to
    professionals. Boehringer Mannheim has also recently received FDA
    clearance for patient self-testing for this product. International
    Technidyne's incision devices compete with products offered by a number
    of companies, including Organon Teknika; Becton, Dickinson and Company;
    and Sherwood Medical Company. International Technidyne's products compete
    primarily on the basis of quality, reliability, price, and reputation.

        Medical-grade Polymers and Enteral Nutrition-delivery Systems. In the
    market for medical-grade polymers and enteral nutrition-delivery systems,
    the Company competes primarily with large pharmaceutical, medical-device,
    and chemical companies, many of which have substantially greater
    financial, technical, and human resources than those of the Company.
    Competition within these markets is intense, and is based primarily on
    price, efficacy, and technological advances.

        (xii) Environmental Protection Regulations

        The Company believes that compliance by the Company with federal,
    state, and local environmental protection regulations will not have a
    material adverse effect on its capital expenditures, earnings, or
    competitive position.

        (xiii) Number of Employees

        As of January 3, 1998, the Company's Instruments and Other Equipment
    and Biomedical Products segments employed 1,313 and 563 people,
    respectively.

    (d) Financial Information about Exports by Domestic Operations and about
        Foreign Operations

        Financial information about exports by domestic operations and about
    foreign operations is summarized in Note 14 to Consolidated Financial
    Statements in the Registrant's 1997 Annual Report to Shareholders, which
    information is incorporated herein by reference.

                                       13PAGE
<PAGE>
    (e) Executive Officers of the Registrant

                                     Present Title (Year First Became
        Name                   Age   Executive Officer)
        --------------------   ---   ---------------------------------------
        John T. Keiser         62    President (1998)
        Victor L. Poirier      56    Senior Vice President (1983)
        John N. Hatsopoulos*   63    Chief Financial Officer and Senior Vice
                                       President (1983)
        David H. Fine          55    Vice President (1993)
        Paul F. Kelleher       55    Chief Accounting Officer (1985)

        ----------
        *John N. Hatsopoulos and George N. Hatsopoulos, a director of the
         Company, are brothers.

        Each executive officer serves until his successor is chosen or
    appointed and qualified, or until earlier resignation, death, or removal.
    All executive officers have held comparable positions for at least five
    years, either with the Company or with its parent company, Thermo
    Electron. Mr. Keiser was appointed senior vice president of the Company
    in 1994. At the same time he was named president of Thermo Biomedical, a
    newly created subsidiary of Thermo Electron, and named President of the
    Company in March 1998. From 1985 until 1994, Mr. Keiser was President of
    the Eberline Instrument division of Thermo Instrument Systems Inc., a
    majority-owned public subsidiary of Thermo Electron. Dr. Fine is a
    full-time employees of the Company. Messrs. Hatsopoulos and Kelleher are
    full-time employees of Thermo Electron, and Mr. Poirier is a full-time
    employee of Thermo Cardiosystems, but they devote such time to the
    affairs of the Company as the Company's needs reasonably require.

    Item 2. Properties

        The Company believes that its facilities are in good condition and
    are adequate to meet its current needs and that other suitable space is
    readily available if any leases are not extended. The location and
    general character of the Company's properties by industry segment as of
    January 3, 1998, are as follows:

    Instruments and Other Equipment

        The Company owns approximately 81,200 square feet of office,
    engineering, laboratory, and production space primarily in New York,
    England, and Scotland, and leases approximately 607,000 square feet of
    office, engineering, laboratory, and production space principally in
    Minnesota, Massachusetts, California, Washington, Florida, Puerto Rico,
    Mexico, Italy, The Netherlands, Australia, Germany, Spain, South Africa,
    and the United Kingdom, under leases expiring from 1998 through 2010.

                                       14PAGE
<PAGE>
    Biomedical Products

        The Company owns approximately 66,000 square feet of office,
    engineering, laboratory, and production space in New Jersey and leases
    approximately 195,000 square feet of office, engineering, laboratory, and
    production space in Illinois and Massachusetts, under leases expiring in
    1998 through 2004.


    Item 3. Legal Proceedings

        Not applicable.

    Item 4. Submission of Matters to a Vote of Security Holders

        Not applicable.

                                       15PAGE
<PAGE>
                                     PART II

   Item 5. Market for Registrant's Common Equity and Related Stockholder
           Matters

       Information concerning the market and market price for the
   Registrant's Common Stock, $.10 par value, and dividend policy are
   included under the sections labeled "Common Stock Market Information" and
   "Dividend Policy" in the Registrant's 1997 Annual Report to Shareholders
   and is incorporated herein by reference.


   Item 6. Selected Financial Data

       Information concerning the Registrant's selected financial data is
   included under the sections labeled "Selected Financial Information" and
   "Dividend Policy" in the Registrant's 1997 Annual Report to Shareholders
   and is incorporated herein by reference.

   Item 7. Management's Discussion and Analysis of Financial Condition and
           Results of Operations

       The information required under this item is included under the
   heading "Management's Discussion and Analysis of Financial Condition and
   Results of Operations" in the Registrant's 1997 Annual Report to
   Shareholders and is incorporated herein by reference.


   Item 8. Financial Statements and Supplementary Data

       The Registrant's Consolidated Financial Statements as of January 3,
   1998, are included in the Registrant's 1997 Annual Report to Shareholders
   and are incorporated herein by reference.

   Item 9. Changes in and Disagreements with Public Accountants on
           Accounting and Financial Disclosure

       Not applicable.

                                       16PAGE
<PAGE>
                                    PART III

    Item 10. Directors and Executive Officers of the Registrant

        The information concerning directors required under this item is
    incorporated herein by reference from the material contained under the
    caption "Election of Directors" in the Registrant's definitive proxy
    statement to be filed with the Securities and Exchange Commission
    pursuant to Regulation 14A, not later than 120 days after the close of
    the fiscal year. The information concerning delinquent filers pursuant to
    Item 405 of Regulation S-K is incorporated herein by reference from the
    material contained under the heading "Section 16(a) Beneficial Ownership
    Reporting Compliance" under the caption "Stock Ownership" in the
    Registrant's definitive proxy statement to be filed with the Securities
    and Exchange Commission pursuant to Regulation 14A, not later than 120
    days after the close of the fiscal year.


    Item 11. Executive Compensation

        The information required under this item is incorporated herein by
    reference from the material contained under the caption "Executive
    Compensation" in the Registrant's definitive proxy statement to be filed
    with the Securities and Exchange Commission pursuant to Regulation 14A,
    not later than 120 days after the close of the fiscal year.


    Item 12. Security Ownership of Certain Beneficial Owners and Management

        The information required under this item is incorporated herein by
    reference from the material contained under the caption "Stock Ownership"
    in the Registrant's definitive proxy statement to be filed with the
    Securities and Exchange Commission pursuant to Regulation 14A, not later
    than 120 days after the close of the fiscal year.


    Item 13. Certain Relationships and Related Transactions

        The information required under this item is incorporated herein by
    reference from the material contained under the caption "Relationship
    with Affiliates" in the Registrant's definitive proxy statement to be
    filed with the Securities and Exchange Commission pursuant to Regulation
    14A, not later than 120 days after the close of the fiscal year.

                                       17PAGE
<PAGE>
                                     PART IV

    Item 14. Exhibits, Financial Statement Schedules, and Reports on Form 8-K

       (a,d) Financial Statements and Schedules.

             (1)The consolidated financial statements set forth in the list
                below are filed as part of this Report.

             (2)The consolidated financial statement schedule set forth in
                the list below is filed as part of this Report.

             (3)Exhibits filed herewith or incorporated herein by reference
                are set forth in Item 14(c) below.

             List of Financial Statements and Schedules Referenced in this
             Item 14

             Information incorporated by reference from Exhibit 13 filed
             herewith:

                Consolidated Statement of Income
                Consolidated Balance Sheet
                Consolidated Statement of Cash Flows
                Consolidated Statement of Shareholders' Investment
                Notes to Consolidated Financial Statements
                Report of Independent Public Accountants

             Financial Statement Schedules filed herewith:

                Schedule II: Valuation and Qualifying Accounts

             All other schedules are omitted because they are not applicable
             or not required, or because the required information is shown
             either in the financial statements or in the notes thereto.

         (b) Reports on Form 8-K

             None.

         (c) Exhibits

             See Exhibit Index on the page immediately preceding exhibits.

                                       18PAGE
<PAGE>
                                   SIGNATURES

        Pursuant to the requirements of Section 13 or 15(d) of the Securities
    Exchange Act of 1934, the Registrant has duly caused this report to be
    signed by the undersigned, thereunto duly authorized.

    Date: March 18, 1998            THERMEDICS INC.

                                    By: John T. Keiser
                                        ------------------------------
                                        John T. Keiser
                                        President

        Pursuant to the requirements of the Securities Exchange Act of 1934,
    this report has been signed below by the following persons on behalf of
    the Registrant and in the capacities indicated, as of March 18, 1998.

    Signature                       Title
    ---------                       -----
    By: John T. Keiser          President and Director
        -------------------------
        John T. Keiser

    By: John N. Hatsopoulos     Chief Financial Officer, Senior Vice
        -------------------------
        John N. Hatsopoulos            President, and Director

    By: Paul F. Kelleher        Chief Accounting Officer
        -------------------------
        Paul F. Kelleher

    By: Peter O. Crisp          Director
        -------------------------
        Peter O. Crisp

    By: Paul F. Ferrari         Director
        -------------------------
        Paul F. Ferrari

    By: George N. Hatsopoulos   Director
        -------------------------
        George N. Hatsopoulos

    By: John W. Wood Jr.        Chairman of the Board and Director
        -------------------------
        John W. Wood Jr.              

    By: Nicholas T. Zervas      Director
        -------------------------
        Nicholas T. Zervas
                                       19PAGE
<PAGE>
                    Report of Independent Public Accountants

    To the Shareholders and Board of Directors of Thermedics Inc.:

        We have audited, in accordance with generally accepted auditing
    standards, the consolidated financial statements included in Thermedics
    Inc.'s Annual Report to Shareholders incorporated by reference in this
    Form 10-K, and have issued our report thereon dated February 12, 1998.
    Our audits were made for the purpose of forming an opinion on those
    statements taken as a whole. The schedule listed in Item 14 on page 18 is
    the responsibility of the Company's management and is presented for
    purposes of complying with the Securities and Exchange Commission's rules
    and is not part of the basic consolidated financial statements. The
    schedule has been subjected to the auditing procedures applied in the
    audits of the basic consolidated financial statements and, in our
    opinion, fairly states in all material respects the consolidated
    financial data required to be set forth therein in relation to the basic
    consolidated financial statements taken as a whole.



                                            Arthur Andersen LLP



    Boston, Massachusetts
    February 12, 1998


                                       20PAGE
<PAGE>
  SCHEDULE II

                                 THERMEDICS INC.
                        Valuation and Qualifying Accounts

                                 (In thousands)


               Balance at   Provision             Accounts             Balance
                Beginning     Charged   Accounts   Written              at End
  Description     of Year  to Expense  Recovered       Off  Other (a)  of Year
  ----------------------------------------------------------------------------
  Allowance for
   Doubtful Accounts

  Year Ended
   Jan. 3, 1998   $ 4,903    $   815     $     -   $(1,406)  $  (105)  $ 4,207

  Year Ended
   Dec. 28, 1996  $ 4,244    $ 1,352     $   206   $(1,048)  $   149   $ 4,903

  Year Ended
   Dec. 30, 1995  $ 3,908    $   689     $     2   $  (720)  $   365   $ 4,244

  ---------------
  (a) Includes allowance of businesses acquired during the year as described
      in Note 3 to Consolidated Financial Statements in the Registrant's 1997
      Annual Report to Shareholders and the effect of foreign currency
      translation.

                                       21PAGE
<PAGE>
                                  EXHIBIT INDEX

    Exhibit
    Number    Description of Exhibit
    ------------------------------------------------------------------------
      2.1     Asset and Stock Purchase Agreement dated as of January 28,
              1994, between Thermo Electron and Baker Hughes
              Incorporated (filed as Exhibit 2.1 to the Registrant's
              Current Report on Form 8-K relating to events occurring on
              March 16, 1994 [File No. 1-9567] and incorporated herein
              by reference).

      2.2     Assignment and Assumption Agreement dated March 16, 1994,
              among Thermo Electron, the Registrant, and Thermo
              Instrument Systems Inc. (filed as Exhibit 2.2 to the
              Registrant's Current Report on Form 8-K relating to events
              occurring on March 16, 1994 [File No. 1-9567] and
              incorporated herein by reference).

      2.3     Agreement and Plan of Merger dated as of November 29,
              1995, by and among the Registrant, ATI Merger Corp.,
              Analytical Technology, Inc., and, for certain limited
              purposes, Thermo Instrument Systems Inc. (filed as Exhibit
              2 to the Registrant's Current Report on Form 8-K relating
              to events occurring on November 29, 1995 [File No. 1-9567]
              and incorporated herein by reference).

      2.4     Asset and Share Purchase Agreement dated as of November
              29, 1995, by and among Thermo Instrument Systems Inc., ATI
              Acquisition Corp., Analytical Technology, Inc., and, for
              certain limited purposes, the Registrant (filed as Exhibit
              10(a) to the Registrant's Current Report on Form 8-K
              relating to events occurring on November 29, 1995 [File
              No. 1-9567] and incorporated herein by reference).

      2.5     Asset Purchase Agreement dated as of January 25, 1996,
              among Thermedics Detection Limited, Moisture Systems
              Corporation, Moisture Systems Limited, and Anacon
              Corporation (filed as Exhibit 2.5 to the Registrant's
              Annual Report on Form 10-K for the fiscal year ended
              December 30, 1995 [File No. 1-9567] and incorporated
              herein by reference). Schedules to this Agreement have
              been omitted pursuant to Rule 601(b)(2) of Regulation S-K.
              The Registrant hereby undertakes to furnish supplementally
              a copy of any omitted schedule to the Commission upon
              request.

      2.6     Agreement and Plan of Reorganization among Thermo
              Cardiosystems Inc., ITC Acquisition Corp., Thermo Electron
              Corporation, ITC Holdings Inc., and International
              Technidyne Corporation dated as of May 2, 1997 (filed as
              Exhibit 2.1 to Thermo Cardiosystems' Quarterly Report on
              Form 10-Q for the quarter ended March 29, 1997 [File
              No. 1-10114] and incorporated herein by reference).

                                       22PAGE
<PAGE>
                                  EXHIBIT INDEX

    Exhibit
    Number    Description of Exhibit
    ------------------------------------------------------------------------
      3.1     Articles of Organization (filed as Exhibit 3(a) to the
              Registrant's Annual Report on Form 10-K for the fiscal
              year ended December 31, 1988 [File No. 1-9567] and
              incorporated herein by reference).

      3.2     Amendment to Articles of Organization dated October 25,
              1993 (filed as Exhibit 3(c) to the Registrant's Quarterly
              Report on Form 10-Q for the fiscal quarter ended October
              2, 1993 [File No. 1-9567] and incorporated herein by
              reference).

      3.3     Amended and Restated Articles of Incorporation of the
              Registrant (filed as Exhibit 3(i) to the Registrant's
              Quarterly Report on Form 10-Q for the fiscal quarter ended
              June 29, 1996 [File No. 1-9567] and incorporated herein by
              reference).

      3.4     Amended and Restated By-laws of the Registrant (filed as
              Exhibit 3(c) to the Registrant's Quarterly Report on Form
              10-Q for the fiscal quarter ended March 28, 1992 [File No.
              1-9567] and incorporated herein by reference).

      4.1     Fiscal Agency Agreement dated January 5, 1994, among
              Thermo Cardiosystems, Thermo Electron, and Chemical Bank
              (filed as Exhibit 4.11 to Thermo Cardiosystems' Annual
              Report on Form 10-K for the fiscal year ended January 1,
              1994 [File No. 1-10114] and incorporated herein by
              reference).

      4.2     Fiscal Agency Agreement dated November 19, 1993, among
              Thermo Voltek, Thermo Electron, and Chemical Bank (filed
              as Exhibit 4.3 to Thermo Voltek's Annual Report on Form
              10-K for the fiscal year ended January 1, 1994 [File No.
              1-10574] and incorporated herein by reference).

      4.3     Fiscal Agency Agreement dated as of June 3, 1996, among
              Thermedics, Thermo Electron, and Chemical Bank, as fiscal
              agent (filed as Exhibit 4 to the Registrant's Quarterly
              Report on Form 10-Q for the fiscal quarter ended June 29,
              1996 [File No. 1-9567] and incorporated herein by
              reference).

      4.4     Guarantee Reimbursement Agreement dated February 7, 1994,
              among Thermo Cardiosystems, Thermo Voltek, the Registrant,
              and Thermo Electron (filed as Exhibit 4.4 to the
              Registrant's Annual Report on Form 10-K for the fiscal
              year ended January 1, 1994 [File No. 1-9567] and
              incorporated herein by reference).

                                       23PAGE
<PAGE>
                                  EXHIBIT INDEX

    Exhibit
    Number    Description of Exhibit
    ------------------------------------------------------------------------
      4.5     Fiscal Agency Agreement dated as of May 14, 1997, among
              Thermo Cardiosystems Inc., Thermo Electron Corporation,
              and Bankers Trust Company as fiscal agent relating to
              $70 million principal amount of 4 3/4% Convertible
              Subordinated Debentures due 2004 (filed as Exhibit 4 to
              Thermo Cardiosystems' Quarterly Report on Form 10-Q for
              the quarter ended June 28, 1997 [File No. 1-10114] and
              incorporated herein by reference).

              The Registrant hereby agrees, pursuant to Item
              601(b)(4)(iii)(A) of Regulation S-K, to furnish to the
              Commission upon request, a copy of each other instrument
              with respect to other long-term debt of the Company or its
              subsidiaries.

     10.1     Amended and Restated Corporate Services Agreement between
              Thermo Electron and the Registrant dated as of January 3,
              1993 (filed as Exhibit 10(a) to the Registrant's Annual
              Report on Form 10-K for the fiscal year ended January 2,
              1993 [File No. 1-9567] and incorporated herein by
              reference).

     10.2     Lease dated November 1983 between WGO Limited Partnership,
              as Lessor and the Registrant, as Lessee (filed as Exhibit
              10(l) to the Registrant's Registration Statement on Form
              S-1 [Reg. No. 2-96962] and incorporated herein by
              reference; amendments thereto filed as Exhibit 10(l) to
              the Registrant's Annual Report on Form 10-K for the fiscal
              year ended December 31, 1988 [File No. 1-9567] and
              incorporated herein by reference).

     10.3     Thermo Electron Corporate Charter as amended and restated
              effective January 3, 1993 (filed as Exhibit 10(h) to the
              Registrant's Annual Report on Form 10-K for the fiscal
              year ended January 2, 1993 [File No. 1-9567] and
              incorporated herein by reference).

     10.4     Lease dated August 25, 1978, between National Boulevard
              Bank of Chicago and Walpak Company (filed as Exhibit 10(p)
              to the Registrant's Annual Report on Form 10-K for the
              fiscal year ended December 31, 1988 [File No. 1-9567] and
              incorporated herein by reference).

     10.5     Exclusive Base Technology License Agreement between Thermo
              Electron and the Registrant dated January 8, 1988 (filed
              as Exhibit 10(q) to the Registrant's Quarterly Report on
              Form 10-Q for the fiscal quarter ended April 2, 1988 [File
              No. 1-9567] and incorporated herein by reference).

                                       24PAGE
<PAGE>
                                  EXHIBIT INDEX

    Exhibit
    Number    Description of Exhibit
    ------------------------------------------------------------------------
     10.6     Research and Development Contract between Thermo Electron
              and the Registrant dated January 8, 1988 (filed as Exhibit
              10(r) to the Registrant's Quarterly Report on Form 10-Q
              for the fiscal quarter ended April 2, 1988 [File No.
              1-9567] and incorporated herein by reference).

     10.7     Exclusive License and Marketing Agreement between Thermo
              Electron and the Registrant dated January 8, 1988 (filed
              as Exhibit 10(s) to the Registrant's Quarterly Report on
              Form 10-Q for the fiscal quarter ended April 2, 1988 [File
              No. 1-9567] and incorporated herein by reference).

     10.8     Intellectual Property Cross-license Agreement between the
              Registrant and Thermo Cardiosystems (filed as Exhibit
              10(i) to Thermo Cardiosystems' Registration Statement on
              Form S-1 [Reg. No. 33-25144] and incorporated herein by
              reference).

     10.9     Amendment No. 1 dated March 29, 1991, to Exclusive License
              and Marketing Agreement between the Registrant and Thermo
              Electron (filed as Exhibit 10(r) to the Registrant's
              Quarterly Report on Form 10-Q for the fiscal quarter ended
              March 30, 1991 [File No. 1-9567] and incorporated herein
              by reference).

     10.10    Management Agreement by and between Thermo Electron and
              the Registrant dated November 15, 1991 (filed as Exhibit
              10(t) to the Registrant's Annual Report on Form 10-K for
              the fiscal year ended December 28, 1991 [File No. 1-9567]
              and incorporated herein by reference).

     10.11    Agreement dated May 26, 1993, between Thermo Cardiosystems
              and The Polymer Technology Group, Incorporated (filed as
              Exhibit 10(nn) to the Registrant's Quarterly Report on
              Form 10-Q for the fiscal quarter ended July 3, 1993 [File
              No. 1-9567] and incorporated herein by reference).

     10.12    Amended and Restated Master Repurchase Agreement dated as
              of July 2, 1996, between the Registrant and Thermo
              Electron (filed as Exhibit 10.12 to the Registrant's
              Annual Report on Form 10-K for the fiscal year ended
              December 28, 1996 [File No. 1-9567] and incorporated
              herein by reference).

     10.13    $38,000,000 Promissory Note dated as of December 11, 1995,
              issued by the Registrant to Thermo Electron (filed as
              Exhibit 10(b) to the Registrant's Current Report on Form
              8-K relating to events occurring on November 29, 1995
              [File No. 1-9567] and incorporated herein by reference).

                                       25PAGE
<PAGE>
                                  EXHIBIT INDEX

    Exhibit
    Number    Description of Exhibit
    ------------------------------------------------------------------------
     10.14    $15,000,000 Promissory Note dated as of February 13, 1996,
              issued by the Company to Thermo Electron (filed as Exhibit
              10 to the Registrant's Quarterly Report on Form 10-Q for
              the fiscal quarter ended March 30, 1996 [File No. 1-9567]
              and incorporated herein by reference).

    10.15-17  Reserved.

     10.18    Incentive Stock Option Plan of the Registrant (filed as
              Exhibit 10(d) to the Registrant's Registration Statement
              on Form S-1 [Reg. No. 33-84380] and incorporated herein by
              reference). (Maximum number of shares issuable in the
              aggregate under this plan and the Registrant's
              Nonqualified Stock Option Plan is 1,931,923 shares, after
              adjustment to reflect share increases approved in 1986 and
              1992, 5-for-4 stock split effected in January 1985,
              4-for-3 stock split effected in September 1985, and
              3-for-2 stock splits effected in October 1986 and November
              1993.)

     10.19    Nonqualified Stock Option Plan of the Registrant (filed as
              Exhibit 10(e) to the Registrant's Registration Statement
              on Form S-1 [Reg. No. 33-84380] and incorporated herein by
              reference). (Maximum number of shares issuable in the
              aggregate under this plan and the Registrant's Incentive
              Stock Option Plan is 1,931,923 shares, after adjustment to
              reflect share increases approved in 1986 and 1992, 5-for-4
              stock split effected in January 1985, 4-for-3 stock split
              effected in September 1985, and 3-for-2 stock splits
              effected in October 1986 and November 1993.)

     10.20    Equity Incentive Plan of the Registrant (filed as Appendix
              A to the Proxy Statement dated May 10, 1993, of the
              Registrant [File No. 1-9567] and incorporated herein by
              reference). (Maximum number of shares issuable is
              1,500,000 shares, after adjustment to reflect 3-for-2
              stock split effected in November 1993.)

     10.21    Thermedics Inc. - Thermedics Detection Inc. Nonqualified
              Stock Option Plan (filed as Exhibit 10.20 to Thermo
              Electron's Annual Report on Form 10-K for the fiscal year
              ended January 2, 1993 [File No. 1-8002] and incorporated
              herein by reference).

     10.22    Thermedics Inc. - Thermo Sentron Inc. Nonqualified Stock
              Option Plan (filed as Exhibit 10.51 to Thermo
              Cardiosystems' Annual Report on Form 10-K for the fiscal
              year ended December 30, 1995 [File No. 1-10114] and
              incorporated herein by reference).

                                       26PAGE
<PAGE>
                                  EXHIBIT INDEX

    Exhibit
    Number    Description of Exhibit
    ------------------------------------------------------------------------
     10.23    Thermedics Inc. - Thermo Cardiosystems Inc. Nonqualified
              Stock Option Plan (filed as Exhibit 4(b) to Thermo
              Cardiosystems' Registration Statement on Form S-8 [Reg.
              No. 33-45282] and incorporated herein by reference).

     10.24    Thermedics Inc. - Thermo Voltek Corp. Nonqualified Stock
              Option Plan.

     10.25    Directors Stock Option Plan of the Registrant (filed as
              Exhibit 10.20 to the Registrant's Annual Report on Form
              10-K for the fiscal year ended December 31, 1994 [File No.
              1-9567] and incorporated herein by reference).

     10.26    Deferred Compensation Plan for Directors of the Registrant
              (filed as Exhibit 10(g) to the Registrant's Registration
              Statement on Form S-1 [Reg. No. 33-96962] and incorporated
              herein by reference).

              In addition to the stock-based compensation plans of the
              Registrant, the executive officers of the Registrant may
              be granted awards under stock-based compensation plans of
              Thermo Electron for services rendered to the Registrant or
              to such affiliated corporations. The terms of such plans
              are substantially the same as those of the Registrant's
              Equity Incentive Plan.

     10.27    Restated Stock Holdings Assistance Plan and Form of
              Promissory Note.

     10.28    Amended and Restated Master Guarantee Reimbursement and
              Loan Agreement, dated December 10, 1997, between Thermo
              Electron and the Registrant.

     13       Annual Report to Shareholders for the year ended January
              3, 1998 (only those portions incorporated herein by
              reference).

     21       Subsidiaries of the Registrant.

     23       Consent of Arthur Andersen LLP.

     27.1     Financial Data Schedule for the year ended January 3,
              1998.

     27.2     Financial Data Schedule for the year ended December 30,
              1995 (restated for the adoption of SFAS No. 128 and the
              acquisition of International Technidyne Corporation).

     27.3     Financial Data Schedule for the quarter ended March 29,
              1996 (restated for the adoption of SFAS No. 128 and the
              acquisition of International Technidyne Corporation).

                                       27PAGE
<PAGE>
                                  EXHIBIT INDEX

    Exhibit
    Number    Description of Exhibit
    ------------------------------------------------------------------------
     27.4     Financial Data Schedule for the quarter ended June 28,
              1996 (restated for the adoption of SFAS No. 128 and the
              acquisition of International Technidyne Corporation).

     27.5     Financial Data Schedule for the quarter ended September
              28, 1996 (restated for the adoption of SFAS No. 128 and
              the acquisition of International Technidyne Corporation).

     27.6     Financial Data Schedule for the year ended December 28,
              1996 (restated for the adoption of SFAS No. 128 and the
              acquisition of International Technidyne Corporation).

     27.7     Financial Data Schedule for the quarter ended March 29,
              1997 (restated for the adoption of SFAS No. 128).

     27.8     Financial Data Schedule for the quarter ended June 28,
              1997 (restated for the adoption of SFAS No. 128).

     27.9     Financial Data Schedule for the quarter ended September
              27, 1997 (restated for the adoption of SFAS No. 128).