MedVenture Associates

MedVenture Associates is a California-based private equity firm, established in 1986, that focuses on early-stage investments in healthcare and medical technologies across North America. The firm, formerly located in Lincoln, specialized in identifying and funding innovative companies within the medical device, medical information technology, pharmaceutical, and biotechnology sectors. Throughout its operation, MedVenture Associates managed multiple venture capital funds aimed at supporting companies engaged in healthcare devices, life sciences, and related manufacturing. Although it has closed all its funds as of December 31, 2017, the firm played a significant role in fostering advancements in medical practice by investing in entrepreneurs and technologies poised to transform the healthcare landscape.

Wally Buch

Venture Partner

Christopher M. Kaster

Partner

45 past transactions

NeuroPace

Venture Round in 2013
NeuroPace, Inc. specializes in the design, development, manufacturing, and marketing of implantable devices aimed at treating neurological disorders through responsive stimulation. The company's flagship product, the RNS System, is specifically designed for patients with medically refractory partial epilepsy. This system includes a small implantable neurostimulator that monitors brain activity and delivers electrical pulses to targeted areas to prevent seizures. The RNS System comprises various components, such as depth leads and cortical strip leads for implantation, along with external devices like a programmer that allows healthcare professionals to communicate with the neurostimulator. Founded in 1997, NeuroPace is headquartered in Mountain View, California.

OptiScan Biomedical

Private Equity Round in 2013
OptiScan Biomedical Corporation develops glucose monitoring systems for the intensive care unit (ICU)/CCU. It offers OptiScanner, an automated, bedside glucose monitoring system to assist healthcare providers manage the glucose level of critically ill patients. The company’s OptiScanner provides serial blood glucose measurements for a range of glucose concentrations. OptiScan Biomedical Corporation was founded in 1994 and is based in Hayward, California.

Pulmonx

Private Equity Round in 2012
Pulmonx Corporation is a medical technology company focused on developing minimally invasive devices for diagnosing and treating chronic obstructive pulmonary disease (COPD), particularly severe emphysema. The company offers key products including the Zephyr Endobronchial Valve, which addresses hyperinflation in adult patients, and the Chartis Pulmonary Assessment System, a tool that evaluates collateral ventilation through flow and pressure measurements. Additionally, Pulmonx provides the StratX Lung Analysis Platform, a cloud-based service that utilizes computed tomography to analyze lung conditions, aiding in the identification of treatment targets for the Zephyr Valve. With a strong clinical foundation supported by numerous published studies, Pulmonx has received regulatory recognition, including FDA approval for its Zephyr Valve, which is now used by physicians in over 25 countries. The company aims to enhance the quality of life for emphysema patients worldwide, having facilitated the treatment of more than 19,000 patients with over 76,000 valves deployed. Founded in 1995 and headquartered in Redwood City, California, Pulmonx continues to lead in interventional procedures for COPD treatment.

Spinal Modulation

Series D in 2011
Spinal Modulation, Inc. provides medical devices research and development services. The company is based in Menlo Park, California. According to the 2002 Health Assessment on the Prevalence of Chronic Pain, severe chronic pain, as defined by the International Association for the Study of Pain, is prevalent in 10 to 13% of the adult population. Limited treatment options exist for these patients and the burden to the healthcare system is unsustainable. The Spinal Modulation AxiumTM Neurostimulator System is a next-generation intraspinal neuromodulation therapy that stimulates the dorsal root ganglion (DRG) to provide a new pain management option. It has shown promising results in managing chronic intractable leg pain, as well as difficult-to-target anatomies such as the back and foot. By stimulating the DRG, therapy can be adjusted to cover either broad or specific areas of pain throughout the torso and legs, while limiting uncomfortable postural effects typically experienced with other spinal cord stimulators.

PolyRemedy

Series C in 2011
PolyRemedy offers integrated wound management systems designed to increase consistency by extending wound care expertise to the point of care. The PolyRemedy Personalized Woundcare System (PWS) enables clinicians to document care through easy-to-use, web-based assessment tools and order personalized wound dressings, while also providing critical and unprecedented visibility into wound care data. It was founded in 2004 and is headquartered in Concord, Massachusetts.

Activaero

Series A in 2011
Activaero GmbH, a drug delivery company, engages in the research, development, manufacture, and marketing of controlled breathing technologies that are used for the delivery of inhaled therapeutic agents to the human lung and various lung regions. It offers AKITA, a controlled breathing device with smart card technology for the pulmonary delivery of inhaled therapeutics; and Watchhaler, an inhalation device tailored to the needs of children who need to take inhaled medication. The company also provides AKITA², a controlled breathing technology for the pulmonary delivery of inhaled therapeutics in the clinical trial setting; and LimiX, a first flow limitation valve that controls the flow rate. In addition, it offers measurement and diagnostic technologies for use in laboratory settings, including a system to measure the properties of aerosols in a minute. Further, the company provides contract development services for devices to use in clinical trials; and clinical trial logistics services. It markets its products through distributors. Activaero GmbH was founded in 2004 and is based in Gemunden, Germany. It also has locations in Munich, Germany; and Dublin, Ohio.

Sonoma Orthopedics

Series D in 2011
Sonoma Orthopedic Products designs, develops, and delivers proprietary orthopedic implants for physicians to address problematic fractures. The WaviBodyâ„¢ technology platform allows for quick, minimally invasive surgical solutions for active patients. Direct to Bone...Back To Life.

Game Ready

Debt Financing in 2010
Game Ready is a medical device maker focused on treating post-surgical orthopedic sports injuries. The company operates primarily through its flagship product GameReady. The GameReady device essentially provides ice cold water and pressure to injured joints/body parts.

Pulmonx

Series C in 2010
Pulmonx Corporation is a medical technology company focused on developing minimally invasive devices for diagnosing and treating chronic obstructive pulmonary disease (COPD), particularly severe emphysema. The company offers key products including the Zephyr Endobronchial Valve, which addresses hyperinflation in adult patients, and the Chartis Pulmonary Assessment System, a tool that evaluates collateral ventilation through flow and pressure measurements. Additionally, Pulmonx provides the StratX Lung Analysis Platform, a cloud-based service that utilizes computed tomography to analyze lung conditions, aiding in the identification of treatment targets for the Zephyr Valve. With a strong clinical foundation supported by numerous published studies, Pulmonx has received regulatory recognition, including FDA approval for its Zephyr Valve, which is now used by physicians in over 25 countries. The company aims to enhance the quality of life for emphysema patients worldwide, having facilitated the treatment of more than 19,000 patients with over 76,000 valves deployed. Founded in 1995 and headquartered in Redwood City, California, Pulmonx continues to lead in interventional procedures for COPD treatment.

eNeura

Venture Round in 2010
eNeura Inc. is a medical technology company focused on developing portable, non-invasive transcranial magnetic stimulation (TMS) devices for the treatment and prevention of migraines. Its flagship product, the sTMS mini, utilizes single-pulse TMS to provide migraine relief by generating targeted magnetic fields that pass through bone and tissue. This device is designed for both acute and prophylactic treatment of migraines in adolescents aged 12 and older, as well as adults, allowing for convenient use at home or on the go. eNeura was established in 2012 and is headquartered in San Jose, California, with an additional office in Baltimore, Maryland. The company, formerly known as eNeura Therapeutics LLC, rebranded in February 2014. However, it faced financial difficulties and filed for liquidation under Chapter 7 in August 2020.

Spinal Modulation

Series C in 2009
Spinal Modulation, Inc. provides medical devices research and development services. The company is based in Menlo Park, California. According to the 2002 Health Assessment on the Prevalence of Chronic Pain, severe chronic pain, as defined by the International Association for the Study of Pain, is prevalent in 10 to 13% of the adult population. Limited treatment options exist for these patients and the burden to the healthcare system is unsustainable. The Spinal Modulation AxiumTM Neurostimulator System is a next-generation intraspinal neuromodulation therapy that stimulates the dorsal root ganglion (DRG) to provide a new pain management option. It has shown promising results in managing chronic intractable leg pain, as well as difficult-to-target anatomies such as the back and foot. By stimulating the DRG, therapy can be adjusted to cover either broad or specific areas of pain throughout the torso and legs, while limiting uncomfortable postural effects typically experienced with other spinal cord stimulators.

Sleep Solutions

Series F in 2009
Sleep Solutions (SSI) is a privately held diagnostic service provider for home testing and evaluation of sleep-disordered breathing, which includes the diagnosis of Obstructive Sleep Apnea (OSA). Sleep Solutions® offers physicians and their patients a fast, cost-effective, accurate and comfortable alternative to in-laboratory sleep studies. Utilizing proprietary sound analysis technology, their NovaSom® QSG® home-diagnostic system is delivered directly to the patient.

BeneChill

Series C in 2009
BeneChill, Inc., a medical device company, develops non-invasive cooling technologies in the United States and Europe. The company develops non-invasive cooling technologies to improve patient outcomes after acute ischemic events, such as cardiac arrest, stroke, and traumatic brain injury. Its RhinoChill System focuses on reducing patient temperature. The company was founded in 2004 and is headquartered in San Diego, California.

SpinalMotion

Series C in 2009
SpinalMotion is dedicated to preserving motion in the spine for patients with degenerative disc disease. By developing innovative artificial discs and instrumentation, we seek to combine the kinematics of a mobile bearing design with materials designed for low wear and improved longevity. Building upon our international clinical experience since 2002, SpinalMotion obtained FDA approval to conduct lumbar and cervical artificial disc clinical trials in the United States in 2005. SpinalMotion is a private company founded in 2004 by Southern Medical, a spinal implant company in South Africa, and Thomas Weisel Healthcare partners. Three Arch Partners became an investor in 2005, and in 2006 Skyline Ventures and MedVenture Associates joined the company's investor group.

NanoVasc

Series A in 2008
NanoVasc, in stealth mode, is developing medical devices.

PolyRemedy

Series B in 2008
PolyRemedy offers integrated wound management systems designed to increase consistency by extending wound care expertise to the point of care. The PolyRemedy Personalized Woundcare System (PWS) enables clinicians to document care through easy-to-use, web-based assessment tools and order personalized wound dressings, while also providing critical and unprecedented visibility into wound care data. It was founded in 2004 and is headquartered in Concord, Massachusetts.

Amnis

Series C in 2008
Amnis Corporation engages in the development, manufacture, and marketing of cell analysis systems for the imaging and analysis of cells in flow. It provides ImageStream, an instrument that combines the functionalities of microscopy and flow cytometry in a single platform for various applications in drug discovery, basic biomedical research, and diagnostics. The company also offers upgrades for ImageStream system to add additional functionality, including violet and red lasers, and an extended depth of field technology (EDF) option. In addition, it provides IDEAS, a cell image analysis software that is used for the quantitative analysis of cell images, as well as for the evaluation of image-based data in various cell populations. Further, the company provides a calibration reagent for the operation of ImageStream system that allows the instrument to track flow rate and core position; and a sheath solution for the functioning of ImageStream system. Its systems are used in apoptosis, immune synapse analysis, nuclear translocation, leukocyte classification, cell cycle analysis, cell morphology analysis, intracellular molecular trafficking, surface markers co-localization, and gene expression quantitation applications. The company offers its products to academic, biotechnology, and pharmaceutical customers. Amnis Corporation was founded in 1998 and is headquartered in Seattle, Washington.

Pavad Medical

Series C in 2007
PAVAD Medical, Inc., a medical device startup company, develops therapeutic technologies in the areas of obstructive sleep apnea. The company was incorporated in 2002 and is based in Fremont, California.

Game Ready

Venture Round in 2007
Game Ready is a medical device maker focused on treating post-surgical orthopedic sports injuries. The company operates primarily through its flagship product GameReady. The GameReady device essentially provides ice cold water and pressure to injured joints/body parts.

BeneChill

Series B in 2007
BeneChill, Inc., a medical device company, develops non-invasive cooling technologies in the United States and Europe. The company develops non-invasive cooling technologies to improve patient outcomes after acute ischemic events, such as cardiac arrest, stroke, and traumatic brain injury. Its RhinoChill System focuses on reducing patient temperature. The company was founded in 2004 and is headquartered in San Diego, California.

Intact Medical

Series G in 2007
Intact Medical Corporation designs, develops, and markets minimally invasive systems for the volumetric excision of tissue for diagnostic and therapeutic applications in select cancer markets. Intact Medical Corporation was formerly known as Neothermia Corporation and changed its name to Intact Medical Corporation in November 2005. It is driven by its mission to alleviate pain, restore health, and extend life. The company was founded in 1998 and is based in Framingham, Massachusetts.

Sonoma Orthopedics

Series B in 2007
Sonoma Orthopedic Products designs, develops, and delivers proprietary orthopedic implants for physicians to address problematic fractures. The WaviBodyâ„¢ technology platform allows for quick, minimally invasive surgical solutions for active patients. Direct to Bone...Back To Life.

Pulmonx

Series B in 2007
Pulmonx Corporation is a medical technology company focused on developing minimally invasive devices for diagnosing and treating chronic obstructive pulmonary disease (COPD), particularly severe emphysema. The company offers key products including the Zephyr Endobronchial Valve, which addresses hyperinflation in adult patients, and the Chartis Pulmonary Assessment System, a tool that evaluates collateral ventilation through flow and pressure measurements. Additionally, Pulmonx provides the StratX Lung Analysis Platform, a cloud-based service that utilizes computed tomography to analyze lung conditions, aiding in the identification of treatment targets for the Zephyr Valve. With a strong clinical foundation supported by numerous published studies, Pulmonx has received regulatory recognition, including FDA approval for its Zephyr Valve, which is now used by physicians in over 25 countries. The company aims to enhance the quality of life for emphysema patients worldwide, having facilitated the treatment of more than 19,000 patients with over 76,000 valves deployed. Founded in 1995 and headquartered in Redwood City, California, Pulmonx continues to lead in interventional procedures for COPD treatment.

EKOS Corporation

Series C in 2006
EKOS Corporation pioneered the development and the clinical application of ultrasound accelerated thrombolysis, introducing its first system for the treatment of vascular thrombosis in 2005. Today, interventional radiologists, cardiologists and vascular surgeons at leading institutions around the world use the EKOS EkoSonic Endovascular System to provide faster, safer and more complete dissolution of thrombus.

Asthmatx

Series C in 2005
Asthmatx, Inc., a medical device company, focuses on developing and commercializing a therapeutic treatment for asthma in the United States. The company has developed a technology that is designed to deliver controlled thermal energy to the airways of adult patients to reduce the mass of airway smooth muscle in a procedure called Bronchial Thermoplasty. Asthmatx offers an interventional medical device, called the Alair System, for the bronchoscopic treatment of patients with moderate to severe asthma. Asthmatx was founded in 2003 and is headquartered in Mountain View, California. As of October 26, 2010, Asthmatx operates as a wholly-owned subsidiary of [Boston Scientific](/organization/boston-scientific).

Pavad Medical

Series B in 2005
PAVAD Medical, Inc., a medical device startup company, develops therapeutic technologies in the areas of obstructive sleep apnea. The company was incorporated in 2002 and is based in Fremont, California.

OptiScan Biomedical

Venture Round in 2005
OptiScan Biomedical Corporation develops glucose monitoring systems for the intensive care unit (ICU)/CCU. It offers OptiScanner, an automated, bedside glucose monitoring system to assist healthcare providers manage the glucose level of critically ill patients. The company’s OptiScanner provides serial blood glucose measurements for a range of glucose concentrations. OptiScan Biomedical Corporation was founded in 1994 and is based in Hayward, California.

eNeura

Series B in 2005
eNeura Inc. is a medical technology company focused on developing portable, non-invasive transcranial magnetic stimulation (TMS) devices for the treatment and prevention of migraines. Its flagship product, the sTMS mini, utilizes single-pulse TMS to provide migraine relief by generating targeted magnetic fields that pass through bone and tissue. This device is designed for both acute and prophylactic treatment of migraines in adolescents aged 12 and older, as well as adults, allowing for convenient use at home or on the go. eNeura was established in 2012 and is headquartered in San Jose, California, with an additional office in Baltimore, Maryland. The company, formerly known as eNeura Therapeutics LLC, rebranded in February 2014. However, it faced financial difficulties and filed for liquidation under Chapter 7 in August 2020.

Amnis

Series C in 2005
Amnis Corporation engages in the development, manufacture, and marketing of cell analysis systems for the imaging and analysis of cells in flow. It provides ImageStream, an instrument that combines the functionalities of microscopy and flow cytometry in a single platform for various applications in drug discovery, basic biomedical research, and diagnostics. The company also offers upgrades for ImageStream system to add additional functionality, including violet and red lasers, and an extended depth of field technology (EDF) option. In addition, it provides IDEAS, a cell image analysis software that is used for the quantitative analysis of cell images, as well as for the evaluation of image-based data in various cell populations. Further, the company provides a calibration reagent for the operation of ImageStream system that allows the instrument to track flow rate and core position; and a sheath solution for the functioning of ImageStream system. Its systems are used in apoptosis, immune synapse analysis, nuclear translocation, leukocyte classification, cell cycle analysis, cell morphology analysis, intracellular molecular trafficking, surface markers co-localization, and gene expression quantitation applications. The company offers its products to academic, biotechnology, and pharmaceutical customers. Amnis Corporation was founded in 1998 and is headquartered in Seattle, Washington.

Alteer

Venture Round in 2005
Alteer optimizes overall performance of medical practices of any size. Alteer’s Internet based software is the only integrated platform that eliminates paper completely and automates the entire workflow in a physician’s practice - from scheduling to charting to billing and patient messaging.

Intact Medical

Series E in 2005
Intact Medical Corporation designs, develops, and markets minimally invasive systems for the volumetric excision of tissue for diagnostic and therapeutic applications in select cancer markets. Intact Medical Corporation was formerly known as Neothermia Corporation and changed its name to Intact Medical Corporation in November 2005. It is driven by its mission to alleviate pain, restore health, and extend life. The company was founded in 1998 and is based in Framingham, Massachusetts.

PolyRemedy

Series A in 2005
PolyRemedy offers integrated wound management systems designed to increase consistency by extending wound care expertise to the point of care. The PolyRemedy Personalized Woundcare System (PWS) enables clinicians to document care through easy-to-use, web-based assessment tools and order personalized wound dressings, while also providing critical and unprecedented visibility into wound care data. It was founded in 2004 and is headquartered in Concord, Massachusetts.

EKOS Corporation

Series B in 2005
EKOS Corporation pioneered the development and the clinical application of ultrasound accelerated thrombolysis, introducing its first system for the treatment of vascular thrombosis in 2005. Today, interventional radiologists, cardiologists and vascular surgeons at leading institutions around the world use the EKOS EkoSonic Endovascular System to provide faster, safer and more complete dissolution of thrombus.

Aesthera Corporation

Series B in 2005
Aesthera is an innovative company focused on reinventing the world of high technology aesthetics. Based in Pleasanton, California, Aesthera was founded by an experienced team of professionals with decades of combined experience in innovative laser R&D, strong connnections to the medical community and proven successes in establishing global markets for medical devices. At the forefront of advancements in the field of light based aesthetic treatments, Aesthera has developed breakthrough Photopneumatic Therapy (PPx) bringing an unprecedented array of firsts to physicians and patients: First no pain treatments, the first light based therapy to require no pre-treatments, the first to treat legs and backs in under twenty minutes, and the first to offer hygienic treatments that are 4-5x safer and highly effective.

Insulet

Series D in 2004
Insulet Corporation is a medical device company that develops, manufactures, and sells insulin delivery systems for individuals with insulin-dependent diabetes. The company's primary product, the Omnipod System, consists of a disposable, tubeless insulin infusion device that adheres to the body for up to three days, along with a wireless personal diabetes manager for monitoring and control. Insulet markets its products through independent distributors and pharmacy channels, as well as directly to patients in the United States, Canada, Europe, and the Middle East. Founded in 2000, Insulet is headquartered in Acton, Massachusetts, and aims to enhance the quality of life for people managing diabetes through innovative technology.

Aesthera Corporation

Series A in 2004
Aesthera is an innovative company focused on reinventing the world of high technology aesthetics. Based in Pleasanton, California, Aesthera was founded by an experienced team of professionals with decades of combined experience in innovative laser R&D, strong connnections to the medical community and proven successes in establishing global markets for medical devices. At the forefront of advancements in the field of light based aesthetic treatments, Aesthera has developed breakthrough Photopneumatic Therapy (PPx) bringing an unprecedented array of firsts to physicians and patients: First no pain treatments, the first light based therapy to require no pre-treatments, the first to treat legs and backs in under twenty minutes, and the first to offer hygienic treatments that are 4-5x safer and highly effective.

Pulmonx

Series A in 2003
Pulmonx Corporation is a medical technology company focused on developing minimally invasive devices for diagnosing and treating chronic obstructive pulmonary disease (COPD), particularly severe emphysema. The company offers key products including the Zephyr Endobronchial Valve, which addresses hyperinflation in adult patients, and the Chartis Pulmonary Assessment System, a tool that evaluates collateral ventilation through flow and pressure measurements. Additionally, Pulmonx provides the StratX Lung Analysis Platform, a cloud-based service that utilizes computed tomography to analyze lung conditions, aiding in the identification of treatment targets for the Zephyr Valve. With a strong clinical foundation supported by numerous published studies, Pulmonx has received regulatory recognition, including FDA approval for its Zephyr Valve, which is now used by physicians in over 25 countries. The company aims to enhance the quality of life for emphysema patients worldwide, having facilitated the treatment of more than 19,000 patients with over 76,000 valves deployed. Founded in 1995 and headquartered in Redwood City, California, Pulmonx continues to lead in interventional procedures for COPD treatment.

Sleep Solutions

Venture Round in 2003
Sleep Solutions (SSI) is a privately held diagnostic service provider for home testing and evaluation of sleep-disordered breathing, which includes the diagnosis of Obstructive Sleep Apnea (OSA). Sleep Solutions® offers physicians and their patients a fast, cost-effective, accurate and comfortable alternative to in-laboratory sleep studies. Utilizing proprietary sound analysis technology, their NovaSom® QSG® home-diagnostic system is delivered directly to the patient.

Intact Medical

Series D in 2003
Intact Medical Corporation designs, develops, and markets minimally invasive systems for the volumetric excision of tissue for diagnostic and therapeutic applications in select cancer markets. Intact Medical Corporation was formerly known as Neothermia Corporation and changed its name to Intact Medical Corporation in November 2005. It is driven by its mission to alleviate pain, restore health, and extend life. The company was founded in 1998 and is based in Framingham, Massachusetts.

eNeura

Series A in 2002
eNeura Inc. is a medical technology company focused on developing portable, non-invasive transcranial magnetic stimulation (TMS) devices for the treatment and prevention of migraines. Its flagship product, the sTMS mini, utilizes single-pulse TMS to provide migraine relief by generating targeted magnetic fields that pass through bone and tissue. This device is designed for both acute and prophylactic treatment of migraines in adolescents aged 12 and older, as well as adults, allowing for convenient use at home or on the go. eNeura was established in 2012 and is headquartered in San Jose, California, with an additional office in Baltimore, Maryland. The company, formerly known as eNeura Therapeutics LLC, rebranded in February 2014. However, it faced financial difficulties and filed for liquidation under Chapter 7 in August 2020.

Sleep Solutions

Series E in 2002
Sleep Solutions (SSI) is a privately held diagnostic service provider for home testing and evaluation of sleep-disordered breathing, which includes the diagnosis of Obstructive Sleep Apnea (OSA). Sleep Solutions® offers physicians and their patients a fast, cost-effective, accurate and comfortable alternative to in-laboratory sleep studies. Utilizing proprietary sound analysis technology, their NovaSom® QSG® home-diagnostic system is delivered directly to the patient.

Genteric

Series B in 2001
Genteric, Inc. develops gene-based drug delivery that employs the secretor organs of the patient’s gastrointestinal system to produce and release therapeutic proteins into the bloodstream.

Sleep Solutions

Series D in 2000
Sleep Solutions (SSI) is a privately held diagnostic service provider for home testing and evaluation of sleep-disordered breathing, which includes the diagnosis of Obstructive Sleep Apnea (OSA). Sleep Solutions® offers physicians and their patients a fast, cost-effective, accurate and comfortable alternative to in-laboratory sleep studies. Utilizing proprietary sound analysis technology, their NovaSom® QSG® home-diagnostic system is delivered directly to the patient.

Genteric

Series A in 1997
Genteric, Inc. develops gene-based drug delivery that employs the secretor organs of the patient’s gastrointestinal system to produce and release therapeutic proteins into the bloodstream.

Spinal Dynamics

Series A in 1997
Spinal Dynamics develops neuro-surgical devices for the replacement of spinal disks. The company's Bryan Cervical Disc System is an implanted prosthesis designed to replace and mimic the flexibility and shock-absorbing characteristics of natural intervertebral discs. It features a shock-absorbing elastomer that is intended to cushion the vertebrae and allow movement of the head and neck and is designed to replace the disc that is removed from the patient in cervical spine surgery.